AEP Texas 10-K 20 Feb 20 2019 FY Annual report Financial data

Cover

Cover	12 Months Ended
	Dec. 31, 2019USD ($)shares
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	1-3525
Entity Registrant Name	AMERICAN ELECTRIC POWER CO INC.
Entity Incorporation, State or Country Code	NY
Entity Tax Identification Number	13-4922640
Entity Address, Address Line One	1 Riverside Plaza,
Entity Address, City or Town	Columbus,
Entity Address, State or Province	OH
Entity Address, Postal Zip Code	43215-2373
City Area Code	(614)
Local Phone Number	716-1000
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float | $	$ 43,491,855,142
Entity Common Stock, Shares Outstanding	494,169,471
Documents Incorporated by Reference	Documents Incorporated By Reference Description Part of Form 10-K into which Document is Incorporated Portions of Annual Reports of the following companies for the fiscal year ended December 31, 2019: Part II American Electric Power Company, Inc. AEP Texas Inc. AEP Transmission Company, LLC Appalachian Power Company Indiana Michigan Power Company Ohio Power Company Public Service Company of Oklahoma Southwestern Electric Power Company Portions of Proxy Statement of American Electric Power Company, Inc. for 2020 Annual Meeting of Shareholders. Part III
Entity Central Index Key	0000004904
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
AEP Texas Inc. [Member]
Entity Information [Line Items]
Entity File Number	333-221643
Entity Registrant Name	AEP TEXAS INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	51-0007707
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding	100,000,000
Entity Central Index Key	0001721781
AEP Transmission Co [Member]
Entity Information [Line Items]
Entity File Number	333-217143
Entity Registrant Name	AEP TRANSMISSION COMPANY, LLC
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-1125168
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Central Index Key	0001702494
Appalachian Power Co [Member]
Entity Information [Line Items]
Entity File Number	1-3457
Entity Registrant Name	APPALACHIAN POWER COMPANY
Entity Incorporation, State or Country Code	VA
Entity Tax Identification Number	54-0124790
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding	13,499,500,000,000
Entity Central Index Key	0000006879
Indiana Michigan Power Co [Member]
Entity Information [Line Items]
Entity File Number	1-3570
Entity Registrant Name	INDIANA MICHIGAN POWER COMPANY
Entity Incorporation, State or Country Code	IN
Entity Tax Identification Number	35-0410455
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding	1,400,000,000,000
Entity Central Index Key	0000050172
Ohio Power Co [Member]
Entity Information [Line Items]
Entity File Number	1-6543
Entity Registrant Name	OHIO POWER COMPANY
Entity Incorporation, State or Country Code	OH
Entity Tax Identification Number	31-4271000
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding	27,952,473,000,000
Entity Central Index Key	0000073986
Public Service Co Of Oklahoma [Member]
Entity Information [Line Items]
Entity File Number	0-343
Entity Registrant Name	PUBLIC SERVICE COMPANY OF OKLAHOMA
Entity Incorporation, State or Country Code	OK
Entity Tax Identification Number	73-0410895
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding	9,013,000,000,000
Entity Central Index Key	0000081027
Southwestern Electric Power Co [Member]
Entity Information [Line Items]
Entity File Number	1-3146
Entity Registrant Name	SOUTHWESTERN ELECTRIC POWER COMPANY
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	72-0323455
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding	7,536,640,000,000
Entity Central Index Key	0000092487
New York Stock Exchange | Common Stock, $6.50 par value
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, $6.50 par value
Trading Symbol	AEP
Security Exchange Name	NYSE
New York Stock Exchange | 6.125% Corporate Units
Entity Information [Line Items]
Title of 12(b) Security	6.125% Corporate Units
Trading Symbol	AEP PR B
Security Exchange Name	NYSE

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues
Revenue from Contracts with Customers	$ 15,561.4	$ 16,195.7	$ 15,424.9
Sales to AEP Affiliates	0	0	0
TOTAL REVENUES	15,561.4	16,195.7	15,424.9
Expenses
Other Operation	2,743.7	2,979.2	2,525.2
Maintenance	1,213.9	1,247.4	1,145.6
Asset Impairments and Other Related Charges	156.4	70.6	87.1
Gain on Sale of Merchant Generation Assets	0	0	(226.4)
Depreciation and Amortization	2,514.5	2,286.6	1,997.2
Taxes Other Than Income Taxes	1,234.5	1,142.7	1,059.4
TOTAL EXPENSES	12,969.1	13,513	11,899.9
OPERATING INCOME (LOSS)	2,592.3	2,682.7	3,525
Other Income (Expense):
Other Income	26.6	18.2	34.6
Allowance for Equity Funds Used During Construction	168.4	132.5	93.7
Non-Service Cost Components of Net Periodic Benefit Cost	120	124.5	45.5
Gain on Sale of Equity Investment	0	0	12.4
Interest Expense	(1,072.5)	(984.4)	(895)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	1,834.8	1,973.5	2,816.2
Income Tax Expense (Benefit)	(12.9)	115.3	969.7
Equity Earnings (Loss) of Unconsolidated Subsidiaries	72.1	73.1	82.4
NET INCOME (LOSS)	1,919.8	1,931.3	1,928.9
Net Income Attributable to Noncontrolling Interests	(1.3)	7.5	16.3
EARNINGS ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ 1,921.1	$ 1,923.8	$ 1,912.6
Earnings Per Share
WEIGHTED AVERAGE NUMBER OF BASIC AEP COMMON SHARES OUTSTANDING	493,694,345	492,774,600	491,814,651
TOTAL BASIC EARNINGS PER SHARE ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS	$ 3.89	$ 3.90	$ 3.89
WEIGHTED AVERAGE NUMBER OF DILUTED AEP COMMON SHARES OUTSTANDING	495,306,238	493,758,277	492,611,067
TOTAL DILUTED EARNINGS PER SHARE ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS	$ 3.88	$ 3.90	$ 3.88
Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	$ 9,245.7	$ 9,556.7	$ 9,095.1
Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	4,319	4,552.3	4,328.9
Generation and Marketing Revenues [Member]
Revenues
Revenue from Contracts with Customers	1,721.8	1,818.1	1,771.4
Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	274.9	268.6	229.5
TOTAL REVENUES	61.7	25
Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	1,940.9	2,359.4	2,346.5
Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	3,165.2	3,427.1	2,965.3
AEP Texas Inc. [Member]
Revenues
Revenue from Contracts with Customers	1,551.6	1,493
Sales to AEP Affiliates	160.5	105.2	65.7
TOTAL REVENUES	1,709.3	1,595.3	1,538.4
Expenses
Other Operation	492	488.9	453.1
Maintenance	158.8	89.4	75.9
Asset Impairments and Other Related Charges	32.5	0	0
Depreciation and Amortization	622.3	499.6	450.1
Taxes Other Than Income Taxes	140.6	132.6	122.3
TOTAL EXPENSES	1,477.3	1,249	1,122.3
OPERATING INCOME (LOSS)	232	346.3	416.1
Other Income (Expense):
Interest Income	3.4	0.8	2.9
Allowance for Equity Funds Used During Construction	15.2	20	6.8
Non-Service Cost Components of Net Periodic Benefit Cost	11.3	12.3	3.6
Interest Expense	(137.2)	(147.3)	(142.3)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	124.7	232.1	287.1
Income Tax Expense (Benefit)	(53.6)	20.8	(23.4)
NET INCOME (LOSS)	178.3	211.3	310.5
AEP Texas Inc. [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	1,545.9	1,486.3	1,470.3
AEP Texas Inc. [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.9	3.8	2.4
TOTAL REVENUES	157.1	103.6
AEP Texas Inc. [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	31.1	38.5	20.9
AEP Transmission Co [Member]
Revenues
Revenue from Contracts with Customers	1,042.1	832
Sales to AEP Affiliates	806.7	598.9	568.1
TOTAL REVENUES	1,021.4	776.1	706.9
Expenses
Other Operation	93.9	83.8	60.1
Maintenance	15.4	10.5	8.5
Depreciation and Amortization	176	133.9	95.7
Taxes Other Than Income Taxes	168.9	137.8	109.7
TOTAL EXPENSES	454.2	366	274
OPERATING INCOME (LOSS)	567.2	410.1	432.9
Other Income (Expense):
Interest Income	3	2.5	1.2
Allowance for Equity Funds Used During Construction	84.3	70.6	49
Interest Expense	(97.4)	(83.2)	(70.2)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	557.1	400	412.9
Income Tax Expense (Benefit)	117.4	84.1	142.2
NET INCOME (LOSS)	439.7	315.9	270.7
AEP Transmission Co [Member] | Transmission [Member]
Revenues
Revenue from Contracts with Customers	214.6	177	138
AEP Transmission Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.1	0.2	0.8
TOTAL REVENUES	0	0
Appalachian Power Co [Member]
Revenues
Revenue from Contracts with Customers	2,911.1	2,993.2
Sales to AEP Affiliates	205.3	181.4	172
TOTAL REVENUES	2,924.7	2,967.5	2,934.2
Expenses
Other Operation	567.6	511.6	503.1
Maintenance	255.4	316.9	251.6
Asset Impairments and Other Related Charges	92.9	0	0
Depreciation and Amortization	466.8	428.4	407.9
Taxes Other Than Income Taxes	146.2	134.7	126.4
TOTAL EXPENSES	2,527.4	2,484	2,243.9
OPERATING INCOME (LOSS)	397.3	483.5	690.3
Other Income (Expense):
Interest Income	2.4	1.8	1.4
Carrying Costs Income	0	1.3	1.4
Allowance for Equity Funds Used During Construction	16.6	13.2	9.2
Non-Service Cost Components of Net Periodic Benefit Cost	17	17.9	5.2
Interest Expense	(205)	(194.8)	(190.9)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	228.3	322.9	516.6
Income Tax Expense (Benefit)	(78)	(44.9)	185.3
NET INCOME (LOSS)	306.3	367.8	331.3
Appalachian Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	2,708.2	2,777.1	2,749
Appalachian Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	11.2	9	13.2
TOTAL REVENUES	0	(1.9)
Appalachian Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	607.5	588.9	597.3
Appalachian Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	391	503.5	357.6
Indiana Michigan Power Co [Member]
Revenues
Revenue from Contracts with Customers	2,308.1	2,381
Sales to AEP Affiliates	10.5	22.1	1.8
Other Revenues - Affiliated	63.4	63.4	62.6
TOTAL REVENUES	2,306.7	2,370.7	2,121.2
Expenses
Purchased Electricity from AEP Affiliates	214.9	237.9	223.9
Other Operation	641.2	585.4	591.3
Maintenance	231.2	238.1	208.4
Depreciation and Amortization	350.6	293.1	210.9
Taxes Other Than Income Taxes	105.1	98.9	92.2
TOTAL EXPENSES	1,965.9	1,993.5	1,774
OPERATING INCOME (LOSS)	340.8	377.2	347.2
Other Income (Expense):
Other Income	18.2	19.2	25.6
Allowance for Equity Funds Used During Construction	19.4	11.9	11.1
Non-Service Cost Components of Net Periodic Benefit Cost	17.7	18.1	6.1
Interest Expense	(117.9)	(124.1)	(110.8)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	258.8	290.4	268.1
Income Tax Expense (Benefit)	(10.6)	29.1	81.4
NET INCOME (LOSS)	269.4	261.3	186.7
Indiana Michigan Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	2,222.1	2,272.6	2,042.5
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	10.7	12.6	14.3
Sales to AEP Affiliates	73	70
TOTAL REVENUES	0	(8.2)
Indiana Michigan Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	190.6	318.3	295.1
Indiana Michigan Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	232.3	221.8	152.2
Ohio Power Co [Member]
Revenues
Revenue from Contracts with Customers	2,748.8	3,079.9
Sales to AEP Affiliates	27.3	21	24.4
TOTAL REVENUES	2,797.6	3,063.4	2,883.9
Expenses
Purchased Electricity from AEP Affiliates	156	135.3	108.5
Amortization of Generation Deferrals	65.3	223.9	229.2
Other Operation	742.6	771.3	516
Maintenance	150.1	156	141.2
Depreciation and Amortization	240.9	259.7	225.9
Taxes Other Than Income Taxes	434.2	412.8	391.5
TOTAL EXPENSES	2,396.4	2,643.6	2,318.2
OPERATING INCOME (LOSS)	401.2	419.8	565.7
Other Income (Expense):
Interest Income	3.2	3.4	4.9
Carrying Costs Income	1	1.7	3.6
Allowance for Equity Funds Used During Construction	18.2	9.8	6.4
Non-Service Cost Components of Net Periodic Benefit Cost	14.6	15.5	4.5
Interest Expense	(106.2)	(100.7)	(101.9)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	332	349.5	483.2
Income Tax Expense (Benefit)	34.9	24	159.3
NET INCOME (LOSS)	297.1	325.5	323.9
Ohio Power Co [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	2,759.5	3,033.8	2,853.5
Ohio Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	10.8	8.6	6
TOTAL REVENUES	17.1	4.3
Ohio Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	607.3	684.6	705.9
Public Service Co Of Oklahoma [Member]
Revenues
Revenue from Contracts with Customers	1,512.8	1,536.4
Sales to AEP Affiliates	6.1	5.4	4.3
Provision for Refund	(9.1)	3.8	(43.5)
TOTAL REVENUES	1,481.8	1,547.3	1,427.2
Expenses
Other Operation	315	372.8	315.1
Maintenance	100.7	104.8	120.3
Depreciation and Amortization	169.5	164	130.4
Taxes Other Than Income Taxes	43.3	42.8	40.5
TOTAL EXPENSES	1,282.5	1,404.8	1,255.7
OPERATING INCOME (LOSS)	199.3	142.5	171.5
Other Income (Expense):
Interest Income	1.2	0.1	0.1
Allowance for Equity Funds Used During Construction	2.7	0.4	0.5
Non-Service Cost Components of Net Periodic Benefit Cost	8.4	8.7	3.4
Interest Expense	(66.5)	(63.5)	(53.4)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	145.1	88.2	122.1
Income Tax Expense (Benefit)	7.5	5	50.1
NET INCOME (LOSS)	137.6	83.2	72
Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	1,469.6	1,537.6	1,417.5
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	6.1	4.3	5.4
TOTAL REVENUES	0	0
Public Service Co Of Oklahoma [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	195.1	240.5	134.5
Public Service Co Of Oklahoma [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	458.9	479.9	514.9
Southwestern Electric Power Co [Member]
Revenues
Revenue from Contracts with Customers	1,799.2	1,817
Sales to AEP Affiliates	36.9	35.1	25.9
Provision for Refund	(32)	(6.7)	0
TOTAL REVENUES	1,750.9	1,821.9	1,779.9
Expenses
Other Operation	348	384.2	318.3
Maintenance	145.6	141.5	143.5
Asset Impairments and Other Related Charges	0	0	33.6
Depreciation and Amortization	249.1	239.5	217.4
Taxes Other Than Income Taxes	100.2	99.6	98.3
TOTAL EXPENSES	1,495.2	1,544.2	1,475.9
OPERATING INCOME (LOSS)	255.7	277.7	304
Other Income (Expense):
Interest Income	2.6	5.4	2.7
Allowance for Equity Funds Used During Construction	6.8	6	2.4
Non-Service Cost Components of Net Periodic Benefit Cost	8.5	8.7	3.7
Interest Expense	(119.1)	(127.9)	(123.4)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	154.5	169.9	189.4
Income Tax Expense (Benefit)	(4.7)	20.4	48.1
Equity Earnings (Loss) of Unconsolidated Subsidiaries	3	2.7	(3.8)
NET INCOME (LOSS)	162.2	152.2	137.5
Net Income Attributable to Noncontrolling Interests	3.6	5	12.8
EARNINGS ATTRIBUTABLE TO COMMON SHAREHOLDERS	158.6	147.2	124.7
Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	1,744.6	1,791.9	1,752.1
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	1.4	1.6	1.9
TOTAL REVENUES	0	0
Southwestern Electric Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	472.8	502.3	496.1
Southwestern Electric Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	$ 179.5	$ 177.1	$ 168.7

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net Income (Loss)	$ 1,919.8	$ 1,931.3	$ 1,928.9
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax	(79.4)	14.6	(2.6)
Securities Available for Sale, Net of Tax	0	0	3.5
Amortization of Pension and OPEB Deferred Costs, Net of Tax	(5.6)	(5.3)	1.1
Pension and OPEB Funded Status, Net of Tax	57.7	(33)	86.5
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)	(27.3)	(23.7)	88.5
TOTAL COMPREHENSIVE INCOME (LOSS)	1,892.5	1,907.6	2,017.4
Total Comprehensive Income Attributable to Noncontrolling Interest	(1.3)	7.5	16.3
TOTAL COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO SHAREHOLDERS	1,893.8	1,900.1	2,001.1
AEP Texas Inc. [Member]
Net Income (Loss)	178.3	211.3	310.5
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax	1	1	0.9
Amortization of Pension and OPEB Deferred Costs, Net of Tax	0.2	0.2	0.3
Pension and OPEB Funded Status, Net of Tax	1.1	(1)	1.1
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)	2.3	0.2	2.3
TOTAL COMPREHENSIVE INCOME (LOSS)	180.6	211.5	312.8
AEP Transmission Co [Member]
Net Income (Loss)	439.7	315.9	270.7
Appalachian Power Co [Member]
Net Income (Loss)	306.3	367.8	331.3
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax	(0.9)	(0.9)	(0.7)
Amortization of Pension and OPEB Deferred Costs, Net of Tax	(2.5)	(3.1)	(1.2)
Pension and OPEB Funded Status, Net of Tax	13.4	(2.6)	11.6
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)	10	(6.6)	9.7
TOTAL COMPREHENSIVE INCOME (LOSS)	316.3	361.2	341
Indiana Michigan Power Co [Member]
Net Income (Loss)	269.4	261.3	186.7
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax	1.6	1.6	1.3
Amortization of Pension and OPEB Deferred Costs, Net of Tax	(0.2)	0	0
Pension and OPEB Funded Status, Net of Tax	0.8	(0.6)	2.8
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)	2.2	1	4.1
TOTAL COMPREHENSIVE INCOME (LOSS)	271.6	262.3	190.8
Ohio Power Co [Member]
Net Income (Loss)	297.1	325.5	323.9
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax	(1)	(1.3)	(1.1)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)	(1)	(1.3)	(1.1)
TOTAL COMPREHENSIVE INCOME (LOSS)	296.1	324.2	322.8
Public Service Co Of Oklahoma [Member]
Net Income (Loss)	137.6	83.2	72
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax	(1)	(1)	(0.8)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)	(1)	(1)	(0.8)
TOTAL COMPREHENSIVE INCOME (LOSS)	136.6	82.2	71.2
Southwestern Electric Power Co [Member]
Net Income (Loss)	162.2	152.2	137.5
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax	1.5	4	1.4
Amortization of Pension and OPEB Deferred Costs, Net of Tax	(1.1)	(1.4)	(0.7)
Pension and OPEB Funded Status, Net of Tax	3.7	(3.1)	4.7
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)	4.1	(0.5)	5.4
TOTAL COMPREHENSIVE INCOME (LOSS)	166.3	151.7	142.9
Total Comprehensive Income Attributable to Noncontrolling Interest	3.6	5	12.8
TOTAL COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO SHAREHOLDERS	$ 162.7	$ 146.7	$ 130.1

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash Flow Hedges, Tax	$ (21.1)	$ 3.9	$ (1.4)
Securities Available for Sale, Tax	0	0	1.9
Amortization of Pension and OPEB Deferred Costs, Tax	(1.5)	(1.4)	0.6
Pension and OPEB Funded Status, Tax	15.3	(8.8)	46.7
AEP Texas Inc. [Member]
Cash Flow Hedges, Tax	0.3	0.3	0.5
Amortization of Pension and OPEB Deferred Costs, Tax	0	0.1	0.1
Pension and OPEB Funded Status, Tax	0.3	(0.3)	0.6
Appalachian Power Co [Member]
Cash Flow Hedges, Tax	(0.2)	(0.2)	(0.4)
Amortization of Pension and OPEB Deferred Costs, Tax	(0.7)	(0.8)	(0.6)
Pension and OPEB Funded Status, Tax	3.6	(0.7)	6.3
Indiana Michigan Power Co [Member]
Cash Flow Hedges, Tax	0.4	0.4	0.7
Amortization of Pension and OPEB Deferred Costs, Tax	0	0	0
Pension and OPEB Funded Status, Tax	0.2	(0.2)	1.5
Ohio Power Co [Member]
Cash Flow Hedges, Tax	(0.3)	(0.4)	(0.6)
Public Service Co Of Oklahoma [Member]
Cash Flow Hedges, Tax	(0.3)	(0.3)	(0.4)
Southwestern Electric Power Co [Member]
Cash Flow Hedges, Tax	0.4	1.1	0.8
Amortization of Pension and OPEB Deferred Costs, Tax	(0.3)	(0.4)	(0.4)
Pension and OPEB Funded Status, Tax	$ 1	$ (0.8)	$ 2.5

Condensed Consolidated Statemen

Condensed Consolidated Statements of Changes in Equity - USD ($) $ in Millions	Total	AEP Texas Inc. [Member]	AEP Transmission Co [Member]	Appalachian Power Co [Member]	Indiana Michigan Power Co [Member]	Ohio Power Co [Member]	Public Service Co Of Oklahoma [Member]	Southwestern Electric Power Co [Member]	Common Stock [Member]	Common Stock [Member]Appalachian Power Co [Member]	Common Stock [Member]Indiana Michigan Power Co [Member]	Common Stock [Member]Ohio Power Co [Member]	Common Stock [Member]Public Service Co Of Oklahoma [Member]	Common Stock [Member]Southwestern Electric Power Co [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member]AEP Texas Inc. [Member]	Additional Paid-in Capital [Member]AEP Transmission Co [Member]	Additional Paid-in Capital [Member]Appalachian Power Co [Member]	Additional Paid-in Capital [Member]Indiana Michigan Power Co [Member]	Additional Paid-in Capital [Member]Ohio Power Co [Member]	Additional Paid-in Capital [Member]Public Service Co Of Oklahoma [Member]	Additional Paid-in Capital [Member]Southwestern Electric Power Co [Member]	Retained Earnings [Member]	Retained Earnings [Member]AEP Texas Inc. [Member]	Retained Earnings [Member]AEP Transmission Co [Member]	Retained Earnings [Member]Appalachian Power Co [Member]	Retained Earnings [Member]Indiana Michigan Power Co [Member]	Retained Earnings [Member]Ohio Power Co [Member]	Retained Earnings [Member]Public Service Co Of Oklahoma [Member]	Retained Earnings [Member]Southwestern Electric Power Co [Member]	Accumulated Other Comprehensive Income [Member]	Accumulated Other Comprehensive Income [Member]AEP Texas Inc. [Member]	Accumulated Other Comprehensive Income [Member]Appalachian Power Co [Member]	Accumulated Other Comprehensive Income [Member]Indiana Michigan Power Co [Member]	Accumulated Other Comprehensive Income [Member]Ohio Power Co [Member]	Accumulated Other Comprehensive Income [Member]Public Service Co Of Oklahoma [Member]	Accumulated Other Comprehensive Income [Member]Southwestern Electric Power Co [Member]	Noncontrolling Interests [Member]	Noncontrolling Interests [Member]Southwestern Electric Power Co [Member]	AEP Wind Holdings LLC [Member]	AEP Wind Holdings LLC [Member]Noncontrolling Interests [Member]	Santa Rita East [Member]	Santa Rita East [Member]Noncontrolling Interests [Member]
TOTAL MEMBER'S EQUITY			$ 1,957.6														$ 1,455								$ 502.6
Common Stock, Dividends, Per Share, Declared	$ 2.39
Beginning Balance at Dec. 31, 2016	$ 17,420.1	$ 1,657.1		$ 3,583.5	$ 2,151.8	$ 2,117.5	$ 1,214.1	$ 2,215.2	$ 3,328.3	$ 260.4	$ 56.6	$ 321.2	$ 157.2	$ 135.7	$ 6,332.6	$ 857.9		$ 1,828.7	$ 980.9	$ 838.8	$ 364	$ 676.6	$ 7,892.4	$ 814.1		$ 1,502.8	$ 1,130.5	$ 954.5	$ 689.5	$ 1,411.9	$ (156.3)	$ (14.9)	$ (8.4)	$ (16.2)	$ 3	$ 3.4	$ (9.4)	$ 23.1	$ 0.4
Beginning Balance, Shares at Dec. 31, 2016	512,048,520								512,000,000
Issuance of Common Stock, Value	$ 12.2								$ 1.1						11.1
Issuance of Common Stock, Shares	162,124								200,000
Capital Contributions from Parent		200														200
Capital Contributions from Member		200	361.6														361.6
Common Stock Dividends	$ (1,191.9)																						(1,178.3)
Common Stock Dividends				(120)	(125)	(130)	(70)	(110)																		(120)	(125)	(130)	(70)	(110)
Common Stock Dividends								(13.6)																														(13.6)	(13.6)
Stockholders' Equity, Other	55.8														55																							0.8
Net Income (Loss)	1,912.6							124.7															1,912.6							124.7
Net Income (Loss) Attributable to Noncontrolling Interests	16.3							12.8																														16.3	12.8
Net Income (Loss)	1,928.9	310.5	270.7	331.3	186.7	323.9	72	137.5																310.5	270.7	331.3	186.7	323.9	72
Other Comprehensive Income (Loss)	88.5	2.3		9.7	4.1	(1.1)	(0.8)	5.4																							88.5	2.3	9.7	4.1	(1.1)	(0.8)	5.4
Ending Balance at Dec. 31, 2017	$ 18,313.6	2,169.9		3,804.5	2,217.6	2,310.3	1,215.3	2,234.5	$ 3,329.4	260.4	56.6	321.2	157.2	135.7	6,398.7	1,057.9		1,828.7	980.9	838.8	364	676.6	8,626.7	1,124.6		1,714.1	1,192.2	1,148.4	691.5	1,426.6	(67.8)	(12.6)	1.3	(12.1)	1.9	2.6	(4)	26.6	(0.4)
Ending Balance, Shares at Dec. 31, 2017	512,210,644								512,200,000
TOTAL MEMBER'S EQUITY			2,589.9														1,816.6								773.3
Common Stock, Dividends, Per Share, Declared	$ 2.53
Issuance of Common Stock, Value	$ 73.6								$ 8						65.6
Issuance of Common Stock, Shares	1,239,392								1,300,000
Capital Contributions from Parent		200														200
Capital Contributions from Member		200	664														664
Common Stock Dividends	$ (1,255.5)																						(1,251.1)
Common Stock Dividends				(160)	(124.7)	(337.5)	(50)	(65)																		(160)	(124.7)	(337.5)	(50)	(65)
ASU 2018-02 Adoption	(3)	(0.9)		0.4	(2.4)	0.4	0.5	(1.3)															14	1.8		0.1	0.3			(0.4)	(17)	(2.7)	0.3	(2.7)	0.4	0.5	(0.9)
ASU 2016-01 Adoption	0																						11.9								(11.9)
Common Stock Dividends								(4.3)																														(4.4)	(4.3)
Stockholders' Equity, Other	23.1														21.8																							1.3
Net Income (Loss)	1,923.8							147.2															1,923.8							147.2
Net Income (Loss) Attributable to Noncontrolling Interests	7.5							5																														7.5	5
Net Income (Loss)	1,931.3	211.3	315.9	367.8	261.3	325.5	83.2	152.2																211.3	315.9	367.8	261.3	325.5	83.2
Other Comprehensive Income (Loss)	(23.7)	0.2		(6.6)	1	(1.3)	(1)	(0.5)																							(23.7)	0.2	(6.6)	1	(1.3)	(1)	(0.5)
Ending Balance at Dec. 31, 2018	$ 19,059.4	2,580.5		4,006.1	2,352.8	2,297.4	$ 1,248	2,315.6	$ 3,337.4	260.4	56.6	321.2	157.2	135.7	6,486.1	1,257.9		1,828.7	980.9	838.8	364	676.6	9,325.3	1,337.7		1,922	1,329.1	1,136.4	724.7	1,508.4	(120.4)	(15.1)	(5)	(13.8)	1	2.1	(5.4)	31	0.3
Ending Balance, Shares at Dec. 31, 2018	513,450,036						10,482,000		513,500,000
TOTAL MEMBER'S EQUITY			3,569.8														2,480.6								1,089.2
Common Stock, Dividends, Per Share, Declared	$ 2.71
Issuance of Common Stock, Value	$ 65.3								$ 6						59.3
Issuance of Common Stock, Shares	923,595								900,000
Capital Contributions from Parent		200														200
Capital Contributions from Member		200	0
Common Stock Dividends	$ (1,350)																						(1,345.5)
Common Stock Dividends				(150)	(80)	(85)	$ (11.3)	(37.5)																		(150)	(80)	(85)	(11.3)	(37.5)
Common Stock Dividends								(3.3)																														(4.5)	(3.3)
Stockholders' Equity, Other	(7.6)														(9.8)								62															2.2
Acquisition																																								$ 134.8	$ 134.8	$ 118.8	$ 118.8
Net Income (Loss)	1,921.1							158.6															1,921.1							158.6
Net Income (Loss) Attributable to Noncontrolling Interests	(1.3)							3.6																															3.6				$ (1.3)
Net Income (Loss)	1,919.8	178.3	439.7	306.3	269.4	297.1	137.6	162.2																178.3	439.7	306.3	269.4	297.1	137.6													$ 1,919.8
Other Comprehensive Income (Loss)	(27.3)	2.3		10	2.2	(1)	(1)	4.1																							(27.3)	2.3	10	2.2	(1)	(1)	4.1
Ending Balance at Dec. 31, 2019	$ 19,913.2	$ 2,961.1		$ 4,172.4	$ 2,544.4	$ 2,508.5	$ 1,373.3	$ 2,441.1	$ 3,343.4	$ 260.4	$ 56.6	$ 321.2	$ 157.2	$ 135.7	$ 6,535.6	$ 1,457.9		$ 1,828.7	$ 980.9	$ 838.8	$ 364	$ 676.6	$ 9,900.9	$ 1,516		$ 2,078.3	$ 1,518.5	$ 1,348.5	$ 851	$ 1,629.5	$ (147.7)	$ (12.8)	$ 5	$ (11.6)	$ 0	$ 1.1	$ (1.3)	$ 281	$ 0.6
Ending Balance, Shares at Dec. 31, 2019	514,373,631						10,482,000		514,400,000
TOTAL MEMBER'S EQUITY			$ 4,009.5														$ 2,480.6								$ 1,528.9

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Current Assets
Cash and Cash Equivalents	$ 246.8	$ 234.1
Restricted Cash	185.8	210
Other Temporary Investments	202.7	159.1
Accounts Receivable:
Customers	625.3	699
Accrued Unbilled Revenues	222.4	209.3
Pledged Accounts Receivable - AEP Credit	873.9	999.8
Miscellaneous	27.2	55.2
Allowance for Uncollectible Accounts	(43.7)	(36.8)
Total Accounts Receivable	1,705.1	1,926.5
Fuel	528.5	319
Materials and Supplies	640.7	602.1
Risk Management Assets	172.8	162.8
Regulatory Asset for Under-Recovered Fuel Costs	92.9	150.1
Margin Deposits	60.4	141.4
Prepayments and Other Current Assets	242.1	208.8
TOTAL CURRENT ASSETS	4,077.8	4,113.9
Property, Plant and Equipment
Generation	22,762.4	21,699.9
Transmission	24,808.6	21,531
Distribution	22,443.4	21,195.4
Other Property, Plant and Equipment	4,811.5	4,265
Construction Work in Progress	4,319.8	4,393.9
Total Property, Plant and Equipment	79,145.7	73,085.2
Accumulated Depreciation and Amortization	19,007.6	17,986.1
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	60,138.1	55,099.1
Other Noncurrent Assets
Regulatory Assets	3,158.8	3,310.4
Securitized Assets	858.1	920.6
Spent Nuclear Fuel and Decommissioning Trusts	2,975.7	2,474.9
Goodwill	52.5	52.5
Long-term Risk Management Assets	266.6	254
Operating Lease Assets	957.4	0
Deferred Charges and Other Noncurrent Assets	3,407.3	2,577.4
TOTAL OTHER NONCURRENT ASSETS	11,676.4	9,589.8
TOTAL ASSETS	75,892.3	68,802.8
Current Liabilities
Accounts Payable	2,085.8	1,874.3
Short-term Debt:
Securitized Debt for Receivables - AEP Credit	710	750
Other Short-term Debt	2,128.3	1,160
Total Short-term Debt	2,838.3	1,910
Long-term Debt Due Within One Year	1,598.7	1,698.5
Risk Management Liabilities	114.3	55
Customer Deposits	366.1	412.2
Accrued Taxes	1,357.8	1,218
Accrued Interest	243.6	231.7
Obligations Under Operating Leases	234.1	0
Regulatory Liability for Over-Recovered Fuel Costs	86.6	58.6
Other Current Liabilities	1,373.8	1,190.5
TOTAL CURRENT LIABILITIES	10,299.1	8,648.8
Noncurrent Liabilities
Long-term Debt	25,126.8	21,648.2
Long-term Debt - Affiliated	0	0
Long-term Risk Management Liabilities	261.8	263.4
Deferred Income Taxes	7,588.2	7,086.5
Regulatory Liabilities and Deferred Investment Tax Credits	8,457.6	8,540.3
Asset Retirement Obligations	2,216.6	2,287.7
Employee Benefits and Pension Obligations	466	377.1
Obligations Under Operating Leases	734.6	0
Deferred Credits and Other Noncurrent Liabilities	719.8	782.6
TOTAL NONCURRENT LIABILITIES	45,571.4	40,985.8
TOTAL LIABILITIES	55,870.5	49,634.6
Rate Matters
Commitments and Contingencies
Redeemable Noncontrolling Interest	65.7	69.4
Contingently Redeemable Performance Share Awards	42.9	39.4
Total Mezzanine Equity	108.6	108.8
Equity
Common Stock	3,343.4	3,337.4
Paid-in Capital	6,535.6	6,486.1
Retained Earnings	9,900.9	9,325.3
Accumulated Other Comprehensive Income (Loss)	(147.7)	(120.4)
TOTAL COMMON SHAREHOLDERS' EQUITY	19,632.2	19,028.4
Noncontrolling Interests	281	31
TOTAL EQUITY	19,913.2	19,059.4
TOTAL LIABILITIES AND EQUITY	75,892.3	68,802.8
AEP Texas Inc. [Member]
Current Assets
Cash and Cash Equivalents	3.1	3.1
Restricted Cash	154.7	156.7
Advances to Affiliates	207.2	8
Accounts Receivable:
Customers	116	110.9
Affiliated Companies	10.1	15
Accrued Unbilled Revenues	68.8	70.4
Miscellaneous	0.3	1.9
Allowance for Uncollectible Accounts	(1.8)	(1.3)
Total Accounts Receivable	193.4	196.9
Fuel	5.9	8.8
Materials and Supplies	56.7	52.8
Accrued Tax Benefits	66.1	44.9
Prepayments and Other Current Assets	5.8	5.3
TOTAL CURRENT ASSETS	692.9	476.5
Property, Plant and Equipment
Generation	351.7	352.1
Transmission	4,466.5	3,683.6
Distribution	4,215.2	4,043.2
Other Property, Plant and Equipment	805.9	727.9
Construction Work in Progress	763.9	836.2
Total Property, Plant and Equipment	10,603.2	9,643
Accumulated Depreciation and Amortization	1,758.1	1,651.2
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	8,845.1	7,991.8
Other Noncurrent Assets
Regulatory Assets	280.6	430
Securitized Assets	623.4	649.1
Deferred Charges and Other Noncurrent Assets	147.1	56.3
TOTAL OTHER NONCURRENT ASSETS	1,051.1	1,135.4
TOTAL ASSETS	10,589.1	9,603.7
Current Liabilities
Advances from Affiliates	0	216
Accounts Payable	256.8	276.5
Affiliated Companies	35.6	30.3
Short-term Debt:
Long-term Debt Due Within One Year	392.1	501.1
Risk Management Liabilities	0	0.2
Accrued Taxes	84.9	75.5
Accrued Interest	35.7	37.3
Oklaunion Purchase Power Agreement	22.1	24.3
Obligations Under Operating Leases	12	0
Other Current Liabilities	188	98.3
TOTAL CURRENT LIABILITIES	1,027.2	1,259.5
Noncurrent Liabilities
Long-term Debt	4,166.3	3,380.2
Deferred Income Taxes	965.4	913.1
Regulatory Liabilities and Deferred Investment Tax Credits	1,316.9	1,344.3
Oklaunion Purchase Power Agreement	0	22.1
Obligations Under Operating Leases	71.1	0
Deferred Credits and Other Noncurrent Liabilities	81.1	104
TOTAL NONCURRENT LIABILITIES	6,600.8	5,763.7
TOTAL LIABILITIES	7,628	7,023.2
Rate Matters
Commitments and Contingencies
Equity
Paid-in Capital	1,457.9	1,257.9
Retained Earnings	1,516	1,337.7
Accumulated Other Comprehensive Income (Loss)	(12.8)	(15.1)
TOTAL EQUITY	2,961.1	2,580.5
TOTAL LIABILITIES AND EQUITY	10,589.1	9,603.7
AEP Transmission Co [Member]
Current Assets
Cash and Cash Equivalents	0	0
Advances to Affiliates	85.4	96.9
Accounts Receivable:
Customers	19	11.8
Affiliated Companies	66.1	61
Total Accounts Receivable	85.1	72.8
Materials and Supplies	13.8	19
Accrued Tax Benefits	9.3	33.4
Prepayments and Other Current Assets	3.8	3.4
TOTAL CURRENT ASSETS	197.4	225.5
Property, Plant and Equipment
Transmission	8,137.9	6,515.8
Other Property, Plant and Equipment	269.6	174
Construction Work in Progress	1,485.7	1,578.3
Total Property, Plant and Equipment	9,893.2	8,268.1
Accumulated Depreciation and Amortization	402.3	271.9
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	9,490.9	7,996.2
Other Noncurrent Assets
Regulatory Assets	4.2	12.9
Deferred Property Taxes	193.5	157.9
Deferred Charges and Other Noncurrent Assets	4.8	1.6
TOTAL OTHER NONCURRENT ASSETS	202.5	172.4
TOTAL ASSETS	9,890.8	8,394.1
Current Liabilities
Advances from Affiliates	137	45.4
Accounts Payable	493.4	347.2
Affiliated Companies	71.2	56
Short-term Debt:
Long-term Debt Due Within One Year	0	85
Accrued Taxes	355.6	288.9
Accrued Interest	19.2	15.9
Obligations Under Operating Leases	2.1	0
Other Current Liabilities	14.6	3.8
TOTAL CURRENT LIABILITIES	1,093.1	842.2
Noncurrent Liabilities
Long-term Debt	3,427.3	2,738
Deferred Income Taxes	817.8	704.4
Regulatory Liabilities and Deferred Investment Tax Credits	540.9	521.3
Obligations Under Operating Leases	1.9	0
Deferred Credits and Other Noncurrent Liabilities	0.3	18.4
TOTAL NONCURRENT LIABILITIES	4,788.2	3,982.1
TOTAL LIABILITIES	5,881.3	4,824.3
Rate Matters
Commitments and Contingencies
Equity
Members' Capital	2,480.6	2,480.6
Retained Earnings	1,528.9	1,089.2
TOTAL MEMBER'S EQUITY	4,009.5	3,569.8
TOTAL LIABILITIES AND EQUITY	9,890.8	8,394.1
Appalachian Power Co [Member]
Current Assets
Cash and Cash Equivalents	3.3	4.2
Restricted Cash	23.5	25.6
Advances to Affiliates	22.1	23
Accounts Receivable:
Customers	129	146.5
Affiliated Companies	64.3	73.4
Accrued Unbilled Revenues	59.7	63.5
Miscellaneous	0.5	2.3
Allowance for Uncollectible Accounts	(2.6)	(2.3)
Total Accounts Receivable	250.9	283.4
Fuel	149.7	61.3
Materials and Supplies	105.2	100.1
Risk Management Assets	39.4	57.2
Regulatory Asset for Under-Recovered Fuel Costs	42.5	99.6
Prepayments and Other Current Assets	64	44.3
TOTAL CURRENT ASSETS	700.6	698.7
Property, Plant and Equipment
Generation	6,563.7	6,509.6
Transmission	3,584.1	3,317.7
Distribution	4,201.7	3,989.4
Other Property, Plant and Equipment	571.3	485.8
Construction Work in Progress	593.4	490.2
Total Property, Plant and Equipment	15,514.2	14,792.7
Accumulated Depreciation and Amortization	4,432.3	4,124.4
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	11,081.9	10,668.3
Other Noncurrent Assets
Regulatory Assets	457.2	475.8
Securitized Assets	234.7	258.7
Long-term Risk Management Assets	0.1	0.9
Operating Lease Assets	78.5	0
Deferred Charges and Other Noncurrent Assets	215.3	188.1
TOTAL OTHER NONCURRENT ASSETS	985.8	923.5
TOTAL ASSETS	12,768.3	12,290.5
Current Liabilities
Advances from Affiliates	236.7	205.6
Accounts Payable	307.8	263.8
Affiliated Companies	92.5	84
Short-term Debt:
Long-term Debt Due Within One Year	215.6	430.7
Risk Management Liabilities	1.9	0.4
Customer Deposits	85.8	88.4
Accrued Taxes	99.6	89.3
Obligations Under Operating Leases	15.2	0
Other Current Liabilities	170.9	191.8
TOTAL CURRENT LIABILITIES	1,226	1,354
Noncurrent Liabilities
Long-term Debt	4,148.2	3,631.9
Long-term Risk Management Liabilities	0	0.2
Deferred Income Taxes	1,680.8	1,625.8
Regulatory Liabilities and Deferred Investment Tax Credits	1,268.7	1,449.7
Asset Retirement Obligations	102.1	107.1
Employee Benefits and Pension Obligations	50.9	57.1
Obligations Under Operating Leases	64	0
Deferred Credits and Other Noncurrent Liabilities	55.2	58.6
TOTAL NONCURRENT LIABILITIES	7,369.9	6,930.4
TOTAL LIABILITIES	8,595.9	8,284.4
Rate Matters
Commitments and Contingencies
Equity
Common Stock	260.4	260.4
Paid-in Capital	1,828.7	1,828.7
Retained Earnings	2,078.3	1,922
Accumulated Other Comprehensive Income (Loss)	5	(5)
TOTAL EQUITY	4,172.4	4,006.1
TOTAL LIABILITIES AND EQUITY	12,768.3	12,290.5
Indiana Michigan Power Co [Member]
Current Assets
Cash and Cash Equivalents	2	2.4
Advances to Affiliates	13.2	12.7
Accounts Receivable:
Customers	53.6	63.1
Affiliated Companies	53.7	75
Accrued Unbilled Revenues	2.5	3.6
Miscellaneous	0.3	1.4
Allowance for Uncollectible Accounts	(0.6)	(0.1)
Total Accounts Receivable	109.5	143
Fuel	56.2	37.3
Materials and Supplies	171.3	167.3
Risk Management Assets	9.8	8.6
Accrued Tax Benefits	0	26.6
Regulatory Asset for Under-Recovered Fuel Costs	3	0
Accrued Reimbursement of Spent Nuclear Fuel Costs	24	7.9
Prepayments and Other Current Assets	14	24.6
TOTAL CURRENT ASSETS	403	430.4
Property, Plant and Equipment
Generation	5,099.7	4,887.2
Transmission	1,641.8	1,576.8
Distribution	2,437.6	2,249.7
Other Property, Plant and Equipment	632.6	583.8
Construction Work in Progress	382.3	465.3
Total Property, Plant and Equipment	10,194	9,762.8
Accumulated Depreciation and Amortization	3,294.3	3,151.6
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	6,899.7	6,611.2
Other Noncurrent Assets
Regulatory Assets	482.1	512.5
Spent Nuclear Fuel and Decommissioning Trusts	2,975.7	2,474.9
Long-term Risk Management Assets	0.1	0.6
Operating Lease Assets	294.9	0
Deferred Charges and Other Noncurrent Assets	181.9	193
TOTAL OTHER NONCURRENT ASSETS	3,934.7	3,181
TOTAL ASSETS	11,237.4	10,222.6
Current Liabilities
Advances from Affiliates	114.4	1.1
Accounts Payable	169.4	174.7
Affiliated Companies	68.4	70.2
Short-term Debt:
Long-term Debt Due Within One Year	139.7	155.4
Risk Management Liabilities	0.5	0.3
Customer Deposits	39.4	38
Accrued Taxes	112.4	90.7
Accrued Interest	36.2	37.3
Obligations Under Operating Leases	87.3	0
Regulatory Liability for Over-Recovered Fuel Costs	6.1	27.4
Other Current Liabilities	109.6	103
TOTAL CURRENT LIABILITIES	883.4	698.1
Noncurrent Liabilities
Long-term Debt	2,910.5	2,880
Long-term Risk Management Liabilities	0	0.1
Deferred Income Taxes	979.7	948
Regulatory Liabilities and Deferred Investment Tax Credits	1,891.4	1,574.5
Asset Retirement Obligations	1,748.6	1,681.3
Obligations Under Operating Leases	211.6	0
Deferred Credits and Other Noncurrent Liabilities	67.8	87.8
TOTAL NONCURRENT LIABILITIES	7,809.6	7,171.7
TOTAL LIABILITIES	8,693	7,869.8
Rate Matters
Commitments and Contingencies
Equity
Common Stock	56.6	56.6
Paid-in Capital	980.9	980.9
Retained Earnings	1,518.5	1,329.1
Accumulated Other Comprehensive Income (Loss)	(11.6)	(13.8)
TOTAL EQUITY	2,544.4	2,352.8
TOTAL LIABILITIES AND EQUITY	11,237.4	10,222.6
Ohio Power Co [Member]
Current Assets
Cash and Cash Equivalents	3.7	4.9
Restricted Cash	0	27.6
Accounts Receivable:
Customers	53	111.1
Affiliated Companies	59.3	70.8
Accrued Unbilled Revenues	20.3	21.4
Miscellaneous	0.5	0.3
Allowance for Uncollectible Accounts	(0.7)	(1)
Total Accounts Receivable	132.4	202.6
Materials and Supplies	52.3	42.9
Renewable Energy Credits	30.9	25.9
Regulatory Asset for Under-Recovered Fuel Costs	0	0.4
Prepayments and Other Current Assets	19.2	15.7
TOTAL CURRENT ASSETS	238.5	319.6
Property, Plant and Equipment
Transmission	2,686.3	2,544.3
Distribution	5,323.5	4,942.3
Other Property, Plant and Equipment	765.8	574.8
Construction Work in Progress	394.4	432.1
Total Property, Plant and Equipment	9,170	8,493.5
Accumulated Depreciation and Amortization	2,263	2,218.6
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	6,907	6,274.9
Other Noncurrent Assets
Regulatory Assets	351.8	387.5
Securitized Assets	0	12.9
Deferred Charges and Other Noncurrent Assets	546.3	441
TOTAL OTHER NONCURRENT ASSETS	898.1	841.4
TOTAL ASSETS	8,043.6	7,435.9
Current Liabilities
Advances from Affiliates	131	114.1
Accounts Payable	233.7	211.9
Affiliated Companies	103.6	102.9
Short-term Debt:
Long-term Debt Due Within One Year	0.1	47.9
Risk Management Liabilities	7.3	5.8
Customer Deposits	70.6	113.1
Accrued Taxes	587.9	537.8
Obligations Under Operating Leases	12.5	0
Regulatory Liability for Over-Recovered Fuel Costs	2.8	0
Other Current Liabilities	151.2	214.2
TOTAL CURRENT LIABILITIES	1,297.9	1,347.7
Noncurrent Liabilities
Long-term Debt	2,081.9	1,668.7
Long-term Risk Management Liabilities	96.3	93.8
Deferred Income Taxes	849.4	763.3
Regulatory Liabilities and Deferred Investment Tax Credits	1,090.9	1,221.2
Obligations Under Operating Leases	76	0
Deferred Credits and Other Noncurrent Liabilities	42.7	43.8
TOTAL NONCURRENT LIABILITIES	4,237.2	3,790.8
TOTAL LIABILITIES	5,535.1	5,138.5
Rate Matters
Commitments and Contingencies
Equity
Common Stock	321.2	321.2
Paid-in Capital	838.8	838.8
Retained Earnings	1,348.5	1,136.4
Accumulated Other Comprehensive Income (Loss)	0	1
TOTAL EQUITY	2,508.5	2,297.4
TOTAL LIABILITIES AND EQUITY	8,043.6	7,435.9
Public Service Co Of Oklahoma [Member]
Current Assets
Cash and Cash Equivalents	1.5	2
Advances to Affiliates	38.8	0
Accounts Receivable:
Customers	28.9	32.5
Affiliated Companies	20.6	26.2
Miscellaneous	0.6	5.7
Allowance for Uncollectible Accounts	(0.3)	(0.1)
Total Accounts Receivable	49.8	64.3
Fuel	12.2	12.3
Materials and Supplies	46.8	44.8
Risk Management Assets	15.8	10.4
Accrued Tax Benefits	11.3	14.7
Prepayments and Other Current Assets	12	9.4
TOTAL CURRENT ASSETS	188.2	157.9
Property, Plant and Equipment
Generation	1,574.6	1,577
Transmission	948.5	892.3
Distribution	2,684.8	2,572.8
Other Property, Plant and Equipment	342.1	303.5
Construction Work in Progress	133.4	94
Total Property, Plant and Equipment	5,683.4	5,439.6
Accumulated Depreciation and Amortization	1,580.1	1,472.9
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	4,103.3	3,966.7
Other Noncurrent Assets
Regulatory Assets	375.2	369
Employee Benefits and Pension Assets	43.9	31.7
Operating Lease Assets	36.8	0
Deferred Charges and Other Noncurrent Assets	4.1	7.1
TOTAL OTHER NONCURRENT ASSETS	460	407.8
TOTAL ASSETS	4,751.5	4,532.4
Current Liabilities
Advances from Affiliates	0	105.5
Accounts Payable	134.3	126.9
Affiliated Companies	59.3	47.1
Short-term Debt:
Long-term Debt Due Within One Year	13.2	375.5
Risk Management Liabilities	0	1
Customer Deposits	58.9	58.6
Accrued Taxes	22.9	22.4
Obligations Under Operating Leases	5.8	0
Regulatory Liability for Over-Recovered Fuel Costs	63.9	20.1
Other Current Liabilities	87.5	64.5
TOTAL CURRENT LIABILITIES	445.8	821.6
Noncurrent Liabilities
Long-term Debt	1,373	911.5
Deferred Income Taxes	628.3	607.8
Regulatory Liabilities and Deferred Investment Tax Credits	837.2	864.7
Asset Retirement Obligations	44.5	46.3
Obligations Under Operating Leases	31	0
Deferred Credits and Other Noncurrent Liabilities	18.4	32.5
TOTAL NONCURRENT LIABILITIES	2,932.4	2,462.8
TOTAL LIABILITIES	3,378.2	3,284.4
Rate Matters
Commitments and Contingencies
Equity
Common Stock	157.2	157.2
Paid-in Capital	364	364
Retained Earnings	851	724.7
Accumulated Other Comprehensive Income (Loss)	1.1	2.1
TOTAL EQUITY	1,373.3	1,248
TOTAL LIABILITIES AND EQUITY	4,751.5	4,532.4
Southwestern Electric Power Co [Member]
Current Assets
Cash and Cash Equivalents	1.6	24.5
Advances to Affiliates	2.1	83.4
Accounts Receivable:
Customers	29	24.5
Affiliated Companies	34.5	28.8
Miscellaneous	13.5	20.2
Allowance for Uncollectible Accounts	(1.7)	(0.7)
Total Accounts Receivable	75.3	72.8
Fuel	140.1	98
Materials and Supplies	94	90
Risk Management Assets	6.4	4.8
Regulatory Asset for Under-Recovered Fuel Costs	4.9	18.8
Prepayments and Other Current Assets	29.7	22.2
TOTAL CURRENT ASSETS	354.1	414.5
Property, Plant and Equipment
Generation	4,691.4	4,672.6
Transmission	2,056.5	1,866.9
Distribution	2,270.7	2,178.6
Other Property, Plant and Equipment	733.4	762.7
Construction Work in Progress	216.9	199.3
Total Property, Plant and Equipment	9,968.9	9,680.1
Accumulated Depreciation and Amortization	2,873.7	2,808.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	7,095.2	6,871.8
Other Noncurrent Assets
Regulatory Assets	222.4	230.8
Deferred Charges and Other Noncurrent Assets	160.5	111.2
TOTAL OTHER NONCURRENT ASSETS	382.9	342
TOTAL ASSETS	7,832.2	7,628.3
Current Liabilities
Advances from Affiliates	59.9	0
Accounts Payable	138	129.1
Affiliated Companies	53.6	64.2
Short-term Debt:
Other Short-term Debt	18.3	0
Long-term Debt Due Within One Year	121.2	59.7
Risk Management Liabilities	1.9	0.4
Customer Deposits	65	64.5
Accrued Taxes	41.8	42.8
Accrued Interest	34.6	34.7
Obligations Under Operating Leases	6.5	0
Regulatory Liability for Over-Recovered Fuel Costs	13.6	11.1
Other Current Liabilities	133.9	117.5
TOTAL CURRENT LIABILITIES	674.7	512.9
Noncurrent Liabilities
Long-term Debt	2,534.4	2,653.7
Long-term Risk Management Liabilities	3.1	2.2
Deferred Income Taxes	940.9	902.8
Regulatory Liabilities and Deferred Investment Tax Credits	892.3	923
Asset Retirement Obligations	196.7	191.3
Employee Benefits and Pension Obligations	28.1	24.8
Obligations Under Operating Leases	34.7	0
Deferred Credits and Other Noncurrent Liabilities	86.2	102
TOTAL NONCURRENT LIABILITIES	4,716.4	4,799.8
TOTAL LIABILITIES	5,391.1	5,312.7
Rate Matters
Commitments and Contingencies
Equity
Common Stock	135.7	135.7
Paid-in Capital	676.6	676.6
Retained Earnings	1,629.5	1,508.4
Accumulated Other Comprehensive Income (Loss)	(1.3)	(5.4)
TOTAL COMMON SHAREHOLDERS' EQUITY	2,440.5	2,315.3
Noncontrolling Interests	0.6	0.3
TOTAL EQUITY	2,441.1	2,315.6
TOTAL LIABILITIES AND EQUITY	$ 7,832.2	$ 7,628.3

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Current Assets
Cash and Cash Equivalents	$ 246.8	$ 234.1
Restricted Cash	185.8	210
Other Temporary Investments	202.7	159.1
Fuel	528.5	319
Materials and Supplies	640.7	602.1
Property, Plant and Equipment
Other Property, Plant and Equipment	4,811.5	4,265
Accumulated Depreciation and Amortization	19,007.6	17,986.1
Current Liabilities
Long-term Debt Due Within One Year	1,598.7	1,698.5
Accrued Interest	243.6	231.7
Other Noncurrent Assets
Securitized Assets	858.1	920.6
Noncurrent Liabilities
Long-term Debt	$ 25,126.8	$ 21,648.2
Equity
Common Stock, Par Value Per Share	$ 6.50	$ 6.50
Common Stock, Shares Authorized	600,000,000	600,000,000
Common Stock, Shares, Issued	514,373,631	513,450,036
Treasury Stock, Shares	20,204,160	20,204,160
Sabine Mining Co [Member]
Current Assets
Materials and Supplies		$ 23
Subsidiaries [Member]
Current Assets
Restricted Cash	$ 185.8	210
Other Temporary Investments	187.8	152.7
Current Liabilities
Long-term Debt Due Within One Year	565.1	406.5
Noncurrent Liabilities
Long-term Debt	907	1,109.2
AEP Texas Inc. [Member]
Current Assets
Cash and Cash Equivalents	3.1	3.1
Restricted Cash	154.7	156.7
Fuel	5.9	8.8
Materials and Supplies	56.7	52.8
Property, Plant and Equipment
Other Property, Plant and Equipment	805.9	727.9
Accumulated Depreciation and Amortization	1,758.1	1,651.2
Current Liabilities
Long-term Debt Due Within One Year	392.1	501.1
Accrued Interest	35.7	37.3
Other Noncurrent Assets
Securitized Assets	623.4	649.1
Noncurrent Liabilities
Long-term Debt	4,166.3	3,380.2
AEP Texas Inc. [Member] | AEP Texas Transition and Restoration Funding [Member]
Current Assets
Restricted Cash	154.7	156.7
Current Liabilities
Long-term Debt Due Within One Year	281.4	251.1
Accrued Interest	7.5	11.3
Other Noncurrent Assets
Securitized Assets	621.2	636.8
Noncurrent Liabilities
Long-term Debt	495.4	540.1
AEP Transmission Co [Member]
Current Assets
Cash and Cash Equivalents	0	0
Materials and Supplies	13.8	19
Property, Plant and Equipment
Other Property, Plant and Equipment	269.6	174
Accumulated Depreciation and Amortization	402.3	271.9
Current Liabilities
Long-term Debt Due Within One Year	0	85
Accrued Interest	19.2	15.9
Noncurrent Liabilities
Long-term Debt	3,427.3	2,738
Appalachian Power Co [Member]
Current Assets
Cash and Cash Equivalents	3.3	4.2
Restricted Cash	23.5	25.6
Fuel	149.7	61.3
Materials and Supplies	105.2	100.1
Property, Plant and Equipment
Other Property, Plant and Equipment	571.3	485.8
Accumulated Depreciation and Amortization	4,432.3	4,124.4
Current Liabilities
Long-term Debt Due Within One Year	215.6	430.7
Other Noncurrent Assets
Securitized Assets	234.7	258.7
Noncurrent Liabilities
Long-term Debt	$ 4,148.2	$ 3,631.9
Equity
Common Stock, Shares Authorized	30,000,000	30,000,000
Common Stock, Shares Outstanding	13,499,500	13,499,500
Indiana Michigan Power Co [Member]
Current Assets
Cash and Cash Equivalents	$ 2	$ 2.4
Fuel	56.2	37.3
Materials and Supplies	171.3	167.3
Property, Plant and Equipment
Other Property, Plant and Equipment	632.6	583.8
Accumulated Depreciation and Amortization	3,294.3	3,151.6
Current Liabilities
Long-term Debt Due Within One Year	139.7	155.4
Accrued Interest	36.2	37.3
Noncurrent Liabilities
Long-term Debt	$ 2,910.5	$ 2,880
Equity
Common Stock, No Par Value	$ 0	$ 0
Common Stock, Shares Authorized	2,500,000	2,500,000
Common Stock, Shares Outstanding	1,400,000	1,400,000
Indiana Michigan Power Co [Member] | DCC Fuel [Member]
Current Liabilities
Long-term Debt Due Within One Year	$ 86.1	$ 76.8
Ohio Power Co [Member]
Current Assets
Cash and Cash Equivalents	3.7	4.9
Restricted Cash	0	27.6
Materials and Supplies	52.3	42.9
Property, Plant and Equipment
Other Property, Plant and Equipment	765.8	574.8
Accumulated Depreciation and Amortization	2,263	2,218.6
Current Liabilities
Long-term Debt Due Within One Year	0.1	47.9
Other Noncurrent Assets
Securitized Assets	0	12.9
Noncurrent Liabilities
Long-term Debt	$ 2,081.9	$ 1,668.7
Equity
Common Stock, No Par Value	$ 0	$ 0
Common Stock, Shares Authorized	40,000,000	40,000,000
Common Stock, Shares Outstanding	27,952,473	27,952,473
Ohio Power Co [Member] | Ohio Phase-In-Recovery Funding [Member]
Current Liabilities
Long-term Debt Due Within One Year	$ 0	$ 47.8
Other Noncurrent Assets
Securitized Assets	0	13
Public Service Co Of Oklahoma [Member]
Current Assets
Cash and Cash Equivalents	1.5	2
Fuel	12.2	12.3
Materials and Supplies	46.8	44.8
Property, Plant and Equipment
Other Property, Plant and Equipment	342.1	303.5
Accumulated Depreciation and Amortization	1,580.1	1,472.9
Current Liabilities
Long-term Debt Due Within One Year	13.2	375.5
Noncurrent Liabilities
Long-term Debt	$ 1,373	$ 911.5
Equity
Common Stock, Par Value Per Share	$ 15	$ 15
Common Stock, Shares Authorized	11,000,000	11,000,000
Common Stock, Shares, Issued	10,482,000	10,482,000
Common Stock, Shares Outstanding	9,013,000	9,013,000
Southwestern Electric Power Co [Member]
Current Assets
Cash and Cash Equivalents	$ 1.6	$ 24.5
Fuel	140.1	98
Materials and Supplies	94	90
Property, Plant and Equipment
Other Property, Plant and Equipment	733.4	762.7
Accumulated Depreciation and Amortization	2,873.7	2,808.3
Current Liabilities
Long-term Debt Due Within One Year	121.2	59.7
Accrued Interest	34.6	34.7
Noncurrent Liabilities
Long-term Debt	$ 2,534.4	$ 2,653.7
Equity
Common Stock, Par Value Per Share	$ 18	$ 18
Common Stock, Shares Authorized	7,600,000	7,600,000
Common Stock, Shares Outstanding	7,536,640	7,536,640
Southwestern Electric Power Co [Member] | Sabine Mining Co [Member]
Current Assets
Cash and Cash Equivalents	$ 0	$ 22
Fuel	47	13.2
Materials and Supplies	23.1	22.5
Property, Plant and Equipment
Other Property, Plant and Equipment	212.3	276.9
Accumulated Depreciation and Amortization	$ 107.5	$ 174.6

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Activites
NET INCOME (LOSS)	$ 1,919.8	$ 1,931.3	$ 1,928.9
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	2,514.5	2,286.6	1,997.2
Rockport Plant, Unit 2 Operating Lease Amortization	136.5	0	0
Deferred Income Taxes	(17.8)	104.3	901.5
Asset Impairments and Other Related Charges	156.4	70.6	87.1
Allowance for Equity Funds Used During Construction	(168.4)	(132.5)	(93.7)
Mark-to-Market of Risk Management Contracts	(29.2)	(66.4)	(23.3)
Amortization of Nuclear Fuel	89.1	113.8	129.1
Pension and Postemployment Benefit Reserves	(24.6)	(42.8)	27.8
Pension Contributions to Qualified Plan Trust	0	0	(93.3)
Property Taxes	(73.8)	(59.1)	(29.5)
Deferred Fuel Over/Under-Recovery, Net	85.2	189.7	84.4
Gain on Sale of Merchant Generation Assets	0	0	(226.4)
Recovery of Ohio Capacity Costs, Net	34.1	67.7	83.2
Refund of Global Settlement	(16.5)	(5.5)	(98.2)
Change in Other Noncurrent Assets	(97.4)	119.8	(423.9)
Change in Other Noncurrent Liabilities	(116.1)	129	181.7
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	247.8	145.9	28.5
Fuel, Materials and Supplies	(248.2)	20.7	17.9
Accounts Payable	5.8	36.6	(58)
Accrued Taxes, Net	138.9	153.2	91.9
Rockport Plant, Unit 2 Operating Lease Payments	(147.7)	0	0
Other Current Assets	70.7	10.5	(60.7)
Other Current Liabilities	(189)	149.8	(181.8)
Net Cash Flows from (Used for) Operating Activities	4,270.1	5,223.2	4,270.4
Investing Activities
Construction Expenditures	(6,051.4)	(6,310.9)	(5,691.3)
Purchases of Investment Securities	(1,576)	(2,067.8)	(2,314.7)
Sales of Investment Securities	1,494.2	2,010	2,256.3
Acquisitions of Nuclear Fuel	(92.3)	(46.1)	(108)
Acquisitions of Assets	(918.4)	0	0
Proceeds From Sale Of Merchant Generation Assets	0	0	2,159.6
Other Investing Activities	(0.6)	61.2	41.7
Net Cash Flows from (Used for) Investing Activities	(7,144.5)	(6,353.6)	(3,656.4)
Financing Activities
Issuance of Common Stock, Net	65.3	73.6	12.2
Issuance of Long-term Debt	4,536.6	4,945.7	3,854.1
Commercial Paper and Credit Facility Borrowings	0	205.6	0
Change in Short-term Debt, Net	928.3	271.4	(74.4)
Retirement of Long-term Debt	(1,220.8)	(2,782)	(3,087.9)
Commercial Paper and Credit Facility Repayments	0	(205.6)	0
Make Whole Premium on Extinguishment of Long-term Debt	(5)	(13.5)	(46.1)
Principal Payments for Finance Lease Obligations	(70.7)	(65.1)	(67.3)
Dividends Paid on Common Stock	(1,350)	(1,255.5)	(1,191.9)
Other Financing Activities	(20.8)	(12.7)	(3.6)
Net Cash Flows from (Used for) Financing Activities	2,862.9	1,161.9	(604.9)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	(11.5)	31.5	9.1
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	444.1	412.6	403.5
Cash and Cash Equivalents at Beginning of Period	234.1
Cash, Cash Equivalents and Restricted Cash at End of Period	432.6	444.1	412.6
Cash and Cash Equivalents at End of Period	246.8	234.1
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	1,022.5	939.3	858.3
Net Cash Paid (Received) for Income Taxes	6.1	(24.7)	(1.1)
Construction Expenditures Included in Current Liabilities as of December 31,	1,341.1	1,120.4	1,330.8
Acquisition of Nuclear Fuel Included in Current Liabilities as of December 31,	0.1	4	0
Expected Reimbursement For Spent Nuclear Fuel Dry Cask Storage	0.3	2.2	2.6
Noncash Increase in Advances to Affiliates, Net due to Contribution of Mutual Energy SWEPCo, LLC	0	84	0
AEP Texas Inc. [Member]
Operating Activites
NET INCOME (LOSS)	178.3	211.3	310.5
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	622.3	499.6	450.1
Deferred Income Taxes	(23.5)	(16.5)	63.3
Asset Impairments and Other Related Charges	32.5	0	0
Allowance for Equity Funds Used During Construction	(15.2)	(20)	(6.8)
Mark-to-Market of Risk Management Contracts	(0.2)	0.7	(0.3)
Pension Contributions to Qualified Plan Trust	0	0	(8.8)
Change in Regulatory Asset - Catastrophe Reserve	44	(24.9)	(99.2)
Change in Other Noncurrent Assets	(34.7)	(35.4)	(49.4)
Change in Other Noncurrent Liabilities	11.3	44.9	8.8
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	3.5	(2.9)	(23.5)
Fuel, Materials and Supplies	(1)	(6)	3.2
Accounts Payable	7.5	(20.3)	30.8
Accrued Taxes, Net	(11.8)	(5.6)	(31.3)
Other Current Assets	(0.4)	0.8	0.6
Other Current Liabilities	10.8	26.2	(15.3)
Net Cash Flows from (Used for) Operating Activities	823.4	651.9	632.7
Investing Activities
Construction Expenditures	(1,275.1)	(1,428.8)	(990.9)
Change in Advances to Affiliates, Net	(199.2)	103.9	(103.3)
Other Investing Activities	2.1	35.2	18.9
Net Cash Flows from (Used for) Investing Activities	(1,472.2)	(1,289.7)	(1,075.3)
Financing Activities
Capital Contributions from Member	200	200	200
Issuance of Long-term Debt	1,070.4	494	749.6
Change in Advances from Affiliates, Net	(216)	216	(169.5)
Retirement of Long-term Debt	(401.8)	(266.1)	(323.1)
Principal Payments for Finance Lease Obligations	(5.1)	(4.7)	(3.9)
Other Financing Activities	(0.7)	1.2	(0.2)
Net Cash Flows from (Used for) Financing Activities	646.8	640.4	452.9
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	(2)	2.6	10.3
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	159.8	157.2	146.9
Cash and Cash Equivalents at Beginning of Period	3.1
Cash, Cash Equivalents and Restricted Cash at End of Period	157.8	159.8	157.2
Cash and Cash Equivalents at End of Period	3.1	3.1
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	148.6	145.9	134.6
Net Cash Paid (Received) for Income Taxes	(11)	7.9	(28.3)
Noncash Acquisitions Under Finance Leases	11.4	10.6	8.2
Construction Expenditures Included in Current Liabilities as of December 31,	225.5	243.1	325.7
AEP Transmission Co [Member]
Operating Activites
NET INCOME (LOSS)	439.7	315.9	270.7
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	176	133.9	95.7
Deferred Income Taxes	91.3	98.9	271.5
Allowance for Equity Funds Used During Construction	(84.3)	(70.6)	(49)
Property Taxes	(35.6)	(32.9)	(22.8)
Change in Other Noncurrent Assets	9.6	14.6	11
Change in Other Noncurrent Liabilities	(8.1)	17.4	27.5
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(5.4)	36.7	(30.4)
Fuel, Materials and Supplies	5.2	(5.4)	(8.6)
Accounts Payable	37.6	(7.5)	23
Accrued Taxes, Net	90.8	73.4	16.3
Accrued Interest	3.3	0.9	4.5
Other Current Assets	(0.3)	(0.3)	(4.8)
Other Current Liabilities	(11.2)	(26.4)	0.2
Net Cash Flows from (Used for) Operating Activities	708.6	548.6	604.8
Investing Activities
Construction Expenditures	(1,410.1)	(1,526.4)	(1,513.4)
Change in Advances to Affiliates, Net	11.5	49.4	(79.2)
Acquisitions of Assets	(9.4)	(37.4)	(9.1)
Other Investing Activities	4.8	1.1	6.1
Net Cash Flows from (Used for) Investing Activities	(1,403.2)	(1,513.3)	(1,595.6)
Financing Activities
Capital Contributions from Member	0	664	361.6
Issuance of Long-term Debt	688	321	617.6
Change in Advances from Affiliates, Net	91.6	29.7	11.6
Retirement of Long-term Debt	(85)	(50)	0
Principal Payments for Finance Lease Obligations	0
Net Cash Flows from (Used for) Financing Activities	694.6	964.7	990.8
Net Increase (Decrease) in Cash and Cash Equivalents	0	0	0
Cash and Cash Equivalents at Beginning of Period	0	0	0
Cash and Cash Equivalents at End of Period	0	0	0
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	90.6	80.2	62.4
Net Cash Paid (Received) for Income Taxes	1.5	(30.7)	(107.3)
Construction Expenditures Included in Current Liabilities as of December 31,	472.7	345	485
Appalachian Power Co [Member]
Operating Activites
NET INCOME (LOSS)	306.3	367.8	331.3
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	466.8	428.4	407.9
Deferred Income Taxes	(126.2)	(16.8)	171.5
Asset Impairments and Other Related Charges	92.9	0	0
Carrying Costs Income	0	(1.3)	(1.4)
Allowance for Equity Funds Used During Construction	(16.6)	(13.2)	(9.2)
Mark-to-Market of Risk Management Contracts	19.9	(33)	(23.1)
Pension Contributions to Qualified Plan Trust	0	0	(10.2)
Deferred Fuel Over/Under-Recovery, Net	57.1	(10.8)	(20.5)
Change in Other Noncurrent Assets	(38.2)	58.1	11.4
Change in Other Noncurrent Liabilities	(40.3)	(4.8)	11.9
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	35.7	33.6	(28)
Fuel, Materials and Supplies	(93.4)	27.8	22.3
Accounts Payable	37.7	(13.3)	37.5
Accrued Taxes, Net	(10.2)	(13.2)	(12.7)
Other Current Assets	15.4	(6.1)	0.7
Other Current Liabilities	(45.5)	42.1	(10.8)
Net Cash Flows from (Used for) Operating Activities	661.4	846.6	880
Investing Activities
Construction Expenditures	(862.6)	(780.7)	(818.1)
Change in Advances to Affiliates, Net	0.9	0.5	0.6
Other Investing Activities	24.3	10.8	15.2
Net Cash Flows from (Used for) Investing Activities	(837.4)	(769.4)	(802.3)
Financing Activities
Issuance of Long-term Debt	478.2	203.2	320.9
Change in Advances from Affiliates, Net	31.1	19.6	106.4
Retirement of Long-term Debt	(180.5)	(124)	(377.9)
Principal Payments for Finance Lease Obligations	(6.7)	(6.9)	(6.9)
Dividends Paid on Common Stock	(150)	(160)	(120)
Other Financing Activities	0.9	1.5	0.5
Net Cash Flows from (Used for) Financing Activities	173	(66.6)	(77)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	(3)	10.6	0.7
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	29.8	19.2	18.5
Cash and Cash Equivalents at Beginning of Period	4.2
Cash, Cash Equivalents and Restricted Cash at End of Period	26.8	29.8	19.2
Cash and Cash Equivalents at End of Period	3.3	4.2
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	190.7	182	183.6
Net Cash Paid (Received) for Income Taxes	63	(13)	31.2
Construction Expenditures Included in Current Liabilities as of December 31,	149.7	134.4	126.3
Indiana Michigan Power Co [Member]
Operating Activites
NET INCOME (LOSS)	269.4	261.3	186.7
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	350.6	293.1	210.9
Rockport Plant, Unit 2 Operating Lease Amortization	69.2	0	0
Deferred Income Taxes	(52.7)	(42.9)	200.7
Amortization (Deferral) of Incremental Nuclear Refueling Outage Expenses, Net	(26.4)	29.2	8.5
Allowance for Equity Funds Used During Construction	(19.4)	(11.9)	(11.1)
Mark-to-Market of Risk Management Contracts	(0.6)	(4.1)	(2.3)
Amortization of Nuclear Fuel	89.1	113.8	129.1
Pension Contributions to Qualified Plan Trust	0	0	(13)
Deferred Fuel Over/Under-Recovery, Net	(24.3)	39.7	13.7
Change in Other Noncurrent Assets	8.3	(36.5)	(101.1)
Change in Other Noncurrent Liabilities	33.7	72.1	37.4
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	35.4	4.8	(1.1)
Fuel, Materials and Supplies	(22.4)	(11.2)	(7.5)
Accounts Payable	3.6	(14.1)	17.6
Accrued Taxes, Net	48.3	41.2	(16.6)
Rockport Plant, Unit 2 Operating Lease Payments	(73.9)	0	0
Other Current Assets	11.2	1.5	14.5
Other Current Liabilities	(13.9)	(10.3)	(5.1)
Net Cash Flows from (Used for) Operating Activities	685.2	725.7	661.3
Investing Activities
Construction Expenditures	(585.9)	(568.5)	(648.5)
Change in Advances to Affiliates, Net	(0.5)	(0.3)	0.1
Purchases of Investment Securities	(1,531)	(2,064.7)	(2,300.5)
Sales of Investment Securities	1,473	2,010	2,256.3
Acquisitions of Nuclear Fuel	(92.3)	(46.1)	(108)
Other Investing Activities	16.6	14.8	9.7
Net Cash Flows from (Used for) Investing Activities	(720.1)	(654.8)	(790.9)
Financing Activities
Issuance of Long-term Debt	123.3	1,168.1	530.1
Change in Advances from Affiliates, Net	113.3	(210.5)	(3.6)
Retirement of Long-term Debt	(117.1)	(884.9)	(260.7)
Principal Payments for Finance Lease Obligations	(5.7)	(8.8)	(12)
Dividends Paid on Common Stock	(80)	(124.7)	(125)
Other Financing Activities	0.7	(9)	0.9
Net Cash Flows from (Used for) Financing Activities	34.5	(69.8)	129.7
Net Increase (Decrease) in Cash and Cash Equivalents	(0.4)	1.1	0.1
Cash and Cash Equivalents at Beginning of Period	2.4	1.3	1.2
Cash and Cash Equivalents at End of Period	2	2.4	1.3
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	111.9	116.9	94.8
Net Cash Paid (Received) for Income Taxes	3.4	32.6	(89.9)
Construction Expenditures Included in Current Liabilities as of December 31,	86	93	88.5
Acquisition of Nuclear Fuel Included in Current Liabilities as of December 31,	0.1	4	0
Expected Reimbursement For Spent Nuclear Fuel Dry Cask Storage	0.3	2.2	2.6
Ohio Power Co [Member]
Operating Activites
NET INCOME (LOSS)	297.1	325.5	323.9
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	240.9	259.7	225.9
Deferred Income Taxes	43.8	(36.2)	147.9
Amortization of Generation Deferrals	65.3	223.9	229.2
Carrying Costs Income	(1)	(1.7)	(3.6)
Allowance for Equity Funds Used During Construction	(18.2)	(9.8)	(6.4)
Mark-to-Market of Risk Management Contracts	4	(32.2)	13
Pension Contributions to Qualified Plan Trust	0	0	(8.2)
Property Taxes	(33.7)	(12.5)	(17.9)
Refund of Global Settlement	(16.5)	(5.5)	(98.2)
Reversal of a Regulatory Provision	(56.2)	0	0
Change in Regulatory Assets	(20.1)	171.5	(70.7)
Change in Other Noncurrent Assets	(35.3)	(11.5)	(54.7)
Change in Other Noncurrent Liabilities	(93.2)	53.8	15.8
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	75	43.1	(30.1)
Fuel, Materials and Supplies	(16.4)	(11.3)	(11.1)
Accounts Payable	0.4	(13.8)	11.6
Accrued Taxes, Net	38.7	26.8	(9.4)
Other Current Assets	0.8	8.1	(9.2)
Other Current Liabilities	(55.2)	49.1	(29.2)
Net Cash Flows from (Used for) Operating Activities	421.2	1,028.7	622.2
Investing Activities
Construction Expenditures	(799.2)	(725.9)	(567.7)
Change in Advances to Affiliates, Net	0	0	24.2
Other Investing Activities	55.1	18.4	12.6
Net Cash Flows from (Used for) Investing Activities	(744.1)	(707.5)	(530.9)
Financing Activities
Issuance of Long-term Debt	444.3	392.8	0
Change in Advances from Affiliates, Net	16.9	26.3	87.8
Retirement of Long-term Debt	(80.3)	(397.1)	(46.4)
Principal Payments for Finance Lease Obligations	(3.5)	(3.8)	(4.1)
Dividends Paid on Common Stock	(85)	(337.5)	(130)
Other Financing Activities	1.7	0.9	0.8
Net Cash Flows from (Used for) Financing Activities	294.1	(318.4)	(91.9)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	(28.8)	2.8	(0.6)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	32.5	29.7	30.3
Cash and Cash Equivalents at Beginning of Period	4.9
Cash, Cash Equivalents and Restricted Cash at End of Period	3.7	32.5	29.7
Cash and Cash Equivalents at End of Period	3.7	4.9
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	100.6	97.1	100
Net Cash Paid (Received) for Income Taxes	7.3	51.3	48.5
Construction Expenditures Included in Current Liabilities as of December 31,	125.9	98.2	87.8
Public Service Co Of Oklahoma [Member]
Operating Activites
NET INCOME (LOSS)	137.6	83.2	72
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	169.5	164	130.4
Deferred Income Taxes	(18.2)	(31.1)	124.7
Allowance for Equity Funds Used During Construction	(2.7)	(0.4)	(0.5)
Mark-to-Market of Risk Management Contracts	(6.4)	(3)	(5.6)
Pension Contributions to Qualified Plan Trust	0	0	(5.3)
Deferred Fuel Over/Under-Recovery, Net	43.8	57.4	(5.4)
Provision for Refund	(9.1)	3.8	(43.5)
Change in Other Noncurrent Assets	5.7	0	(27.2)
Change in Other Noncurrent Liabilities	1.8	17.6	4.5
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	15.4	5.1	(10.9)
Fuel, Materials and Supplies	(1.9)	(2.6)	13
Accounts Payable	7	17.7	(10.7)
Accrued Taxes, Net	3.9	13.2	0.8
Other Current Assets	(0.7)	(0.8)	(2.1)
Other Current Liabilities	4.6	6.4	3.9
Net Cash Flows from (Used for) Operating Activities	350.3	330.5	238.1
Investing Activities
Construction Expenditures	(291.9)	(240.2)	(266.1)
Change in Advances to Affiliates, Net	(38.8)	0	0
Other Investing Activities	2.6	7.2	4.6
Net Cash Flows from (Used for) Investing Activities	(328.1)	(233)	(261.5)
Financing Activities
Issuance of Long-term Debt	349.5	0	0
Change in Advances from Affiliates, Net	(105.5)	(44.1)	97.6
Retirement of Long-term Debt	(250.5)	(0.5)	(0.5)
Make Whole Premium on Extinguishment of Long-term Debt	(3)	0	0
Principal Payments for Finance Lease Obligations	(3.1)	(3.3)	(3.9)
Dividends Paid on Common Stock	(11.3)	(50)	(70)
Other Financing Activities	1.2	0.8	0.3
Net Cash Flows from (Used for) Financing Activities	(22.7)	(97.1)	23.5
Net Increase (Decrease) in Cash and Cash Equivalents	(0.5)	0.4	0.1
Cash and Cash Equivalents at Beginning of Period	2	1.6	1.5
Cash and Cash Equivalents at End of Period	1.5	2	1.6
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	61.1	62	61.5
Net Cash Paid (Received) for Income Taxes	22.4	17.9	(72.6)
Noncash Acquisitions Under Finance Leases	5.3	4.3	2.1
Construction Expenditures Included in Current Liabilities as of December 31,	46	33.2	23.1
Southwestern Electric Power Co [Member]
Operating Activites
NET INCOME (LOSS)	162.2	152.2	137.5
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	249.1	239.5	217.4
Deferred Income Taxes	(11)	1.2	80.5
Asset Impairments and Other Related Charges	0	0	33.6
Allowance for Equity Funds Used During Construction	(6.8)	(6)	(2.4)
Mark-to-Market of Risk Management Contracts	0.8	4	(5.6)
Pension Contributions to Qualified Plan Trust	0	0	(8.9)
Deferred Fuel Over/Under-Recovery, Net	16.5	(2.4)	(0.8)
Provision for Refund	(32)	(6.7)	0
Change in Other Noncurrent Assets	6.2	(18.8)	(9.2)
Change in Other Noncurrent Liabilities	2.7	42.8	4.7
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	0	53.5	(32.9)
Fuel, Materials and Supplies	(46.1)	3.5	(16)
Accounts Payable	(28.4)	0.9	10.5
Accrued Taxes, Net	(3.2)	2.3	45.7
Other Current Assets	(8.9)	15.6	5.2
Other Current Liabilities	6.7	16.5	(14.6)
Net Cash Flows from (Used for) Operating Activities	339.8	504.8	444.7
Investing Activities
Construction Expenditures	(412.7)	(451)	(404.1)
Change in Advances to Affiliates, Net	81.3	(81.4)	167.8
Proceeds from Sales of Assets	0.2	1.4	12.6
Other Investing Activities	1	2.1	3.1
Net Cash Flows from (Used for) Investing Activities	(330.2)	(528.9)	(220.6)
Financing Activities
Issuance of Long-term Debt	0	1,065.7	114.6
Change in Short-term Debt, Net	18.3	(22)	22
Change in Advances from Affiliates, Net	59.9	(118.7)	118.7
Retirement of Long-term Debt	(59.7)	(794.5)	(353.7)
Principal Payments for Finance Lease Obligations	(11)	(11.5)	(11.3)
Dividends Paid on Common Stock	(37.5)	(65)	(110)
Dividends Paid on Common Stock	(3.3)	(4.3)	(13.6)
Other Financing Activities	0.8	(2.7)	0.5
Net Cash Flows from (Used for) Financing Activities	(32.5)	47	(232.8)
Net Increase (Decrease) in Cash and Cash Equivalents	(22.9)	22.9	(8.7)
Cash and Cash Equivalents at Beginning of Period	24.5	1.6	10.3
Cash and Cash Equivalents at End of Period	1.6	24.5	1.6
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	111.1	125.7	124.4
Net Cash Paid (Received) for Income Taxes	8.6	18.8	(75.3)
Noncash Acquisitions Under Finance Leases	7.4	3.6	3.3
Construction Expenditures Included in Current Liabilities as of December 31,	$ 69.1	$ 42	$ 71.2

Organization and Summary of Sig

Organization and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Organization and Summary of Significant Accounting Policies	ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES The disclosures in this note apply to all Registrants unless indicated otherwise. ORGANIZATION The Registrants engage in the generation, transmission and distribution of electric power. The Registrant Subsidiaries that conduct most of these activities are regulated by the FERC under the Federal Power Act and the Energy Policy Act of 2005 and maintain accounts in accordance with the FERC and other regulatory guidelines. Most of these companies are subject to further regulation with regard to rates and other matters by state regulatory commissions. AEP provides competitive electric and gas supply for residential, commercial and industrial customers in deregulated electricity markets and also provides energy management solutions throughout the United States, including energy efficiency services through its independent retail electric supplier. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Rates and Service Regulation AEP’s public utility subsidiaries’ rates are regulated by the FERC and state regulatory commissions in the eleven state operating territories in which they operate. The FERC also regulates the Registrants’ affiliated transactions, including AEPSC intercompany service billings which are generally at cost, under the 2005 Public Utility Holding Company Act and the Federal Power Act. The FERC also has jurisdiction over the issuances and acquisitions of securities of the public utility subsidiaries, the acquisition or sale of certain utility assets and mergers with another electric utility or holding company. The state regulatory commissions also regulate certain intercompany transactions under various orders and affiliate statutes. Both the FERC and state regulatory commissions are permitted to review and audit the relevant books and records of companies within a public utility holding company system. The FERC regulates wholesale power markets and wholesale power transactions. The Registrants’ wholesale power transactions are generally market-based. Wholesale power transactions are cost-based regulated when a cost-based contract is negotiated and filed with the FERC or the FERC determines that the Registrants have “market power” in the region where the transaction occurs. Wholesale power supply contracts have been entered into with various municipalities and cooperatives that are FERC-regulated, cost-based contracts. These contracts are generally formula rate mechanisms, which are trued up to actual costs annually. The state regulatory commissions regulate all of the retail distribution operations and rates of the Registrants’ retail public utility subsidiaries on a cost basis. The state regulatory commissions also regulate the retail generation/power supply operations and rates except in Ohio and the ERCOT region of Texas. For generation in Ohio, customers who have not switched to a CRES provider for generation pay market-based auction rates. In addition, all OPCo distribution customers paid for certain legacy generation deferral balances that were fully recovered as of December 31, 2019 and continue to pay for certain legacy deferred generation-related costs through PUCO approved riders. In the ERCOT region of Texas, the generation/supply business is under customer choice and market pricing is conducted by REPs. AEP has no active REPs in ERCOT. AEP’s nonregulated subsidiaries enter into short and long-term wholesale transactions to buy or sell capacity, energy and ancillary services in the ERCOT market. In addition, these nonregulated subsidiaries control certain wind and coal-fired generation assets, the power from which is marketed and sold in ERCOT. The FERC also regulates the Registrants’ wholesale transmission operations and rates. Retail transmission rates are based upon the FERC OATT rate when retail rates are unbundled in connection with restructuring. Retail transmission rates are based on formula rates included in the PJM OATT that are cost-based and are unbundled in Ohio for OPCo, in Virginia for APCo and in Michigan for I&M. AEP Texas’ retail transmission rates in Texas are unbundled but the retail transmission rates are regulated, on a cost basis, by the PUCT. Bundled retail transmission rates are regulated, on a cost basis, by the state commissions. Transmission rates for AEPTCo’s seven wholly-owned transmission subsidiaries within the AEP Transmission Holdco segment are based on formula rates included in the applicable RTO’s OATT that are cost-based. In West Virginia, APCo and WPCo provide retail electric service at bundled rates approved by the WVPSC, with rates set on a combined cost-of-service basis. In addition, the FERC regulates the SIA, Operating Agreement, Transmission Agreement and Transmission Coordination Agreement, all of which allocate shared system costs and revenues among the utility subsidiaries that are parties to each agreement. The FERC also regulates the PCA. See Note 16 - Related Party Transactions for additional information. Principles of Consolidation AEP’s consolidated financial statements include its wholly-owned and majority-owned subsidiaries and VIEs of which AEP is the primary beneficiary. The consolidated financial statements for AEP Texas include the Registrant Subsidiary, its wholly-owned subsidiaries, Transition Funding (consolidated VIEs) and Restoration Funding (a consolidated VIE). The consolidated financial statements for APCo include the Registrant Subsidiary, its wholly-owned subsidiaries and Appalachian Consumer Rate Relief Funding (a consolidated VIE). The consolidated financial statements for I&M include the Registrant Subsidiary, its wholly-owned subsidiaries and DCC Fuel (consolidated VIEs). The consolidated financial statements for OPCo include the Registrant Subsidiary and Ohio Phase-in-Recovery Funding (a consolidated VIE). In July 2019, the Ohio Phase-in Recovery Funding securitization bonds matured. The consolidated financial statements for SWEPCo include the Registrant Subsidiary, its wholly-owned subsidiary and Sabine (a consolidated VIE). Intercompany items are eliminated in consolidation. The equity method of accounting is used for equity investments where the Registrants exercise significant influence but do not hold a controlling financial interest. Such investments are initially recorded at cost in Deferred Charges and Other Noncurrent Assets on the balance sheets. The proportionate share of the investee’s equity earnings or losses is included in Equity Earnings of Unconsolidated Subsidiaries on the statements of income. AEP, AEP Texas, I&M, PSO and SWEPCo have ownership interests in generating units that are jointly-owned. The proportionate share of the operating costs associated with such facilities is included on the income statements and the assets and liabilities are reflected on the balance sheets. See Note 17 - Variable Interest Entities and Equity Method Investments and Note 18 - Property, Plant and Equipment for additional information. Accounting for the Effects of Cost-Based Regulation The Registrants’ financial statements reflect the actions of regulators that result in the recognition of certain revenues and expenses in different time periods than enterprises that are not rate-regulated. In accordance with accounting guidance for “Regulated Operations,” regulatory assets (deferred expenses) and regulatory liabilities (deferred revenue reductions or refunds) are recorded to reflect the economic effects of regulation in the same accounting period by matching expenses with their recovery through regulated revenues and by matching income with its passage to customers in cost-based regulated rates. Use of Estimates The preparation of these financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. These estimates include, but are not limited to, inventory valuation, allowance for doubtful accounts, goodwill, intangible and long-lived asset impairment, unbilled electricity revenue, valuation of long-term energy contracts, the effects of regulation, long-lived asset recovery, storm costs, the effects of contingencies and certain assumptions made in accounting for pension and postretirement benefits. The estimates and assumptions used are based upon management’s evaluation of the relevant facts and circumstances as of the date of the financial statements. Actual results could ultimately differ from those estimates. Cash and Cash Equivalents Cash and Cash Equivalents include temporary cash investments with original maturities of three months or less. Restricted Cash (Applies to AEP, AEP Texas, APCo and OPCo) Restricted Cash primarily includes funds held by trustees for the payment of securitization bonds and contractually restricted deposits held for the future payment of the remaining construction activities at the Santa Rita East wind generation facility. Reconciliation of Cash, Cash Equivalents and Restricted Cash The following tables provide a reconciliation of Cash, Cash Equivalents and Restricted Cash reported within the balance sheets that sum to the total of the same amounts shown on the statement of cash flows: December 31, 2019 AEP AEP Texas APCo OPCo (in millions) Cash and Cash Equivalents $ 246.8 $ 3.1 $ 3.3 $ 3.7 Restricted Cash 185.8 154.7 23.5 — Total Cash, Cash Equivalents and Restricted Cash $ 432.6 $ 157.8 $ 26.8 $ 3.7 December 31, 2018 AEP AEP Texas APCo OPCo (in millions) Cash and Cash Equivalents $ 234.1 $ 3.1 $ 4.2 $ 4.9 Restricted Cash 210.0 156.7 25.6 27.6 Total Cash, Cash Equivalents and Restricted Cash $ 444.1 $ 159.8 $ 29.8 $ 32.5 Other Temporary Investments (Applies to AEP) Other Temporary Investments primarily include marketable securities and investments by its protected cell of EIS. These securities have readily determinable fair values and are carried at fair value with changes in fair value recognized in net income. The cost of securities sold is based on the specific identification or weighted-average cost method. See “Fair Value Measurements of Other Temporary Investments” section of Note 11 for additional information. Inventory Fossil fuel inventories are carried at average cost with the exception of AGR and AEP’s non-regulated ownership share of Oklaunion Power Station, which is carried at the lower of average cost or net realizable value. Materials and supplies inventories are carried at average cost. AEP and SWEPCo reclassified approximately $23 million , as of December 31, 2018, from Fuel to Materials and Supplies related to Sabine. Accounts Receivable Customer accounts receivable primarily include receivables from wholesale and retail energy customers, receivables from energy contract counterparties related to risk management activities and customer receivables primarily related to other revenue-generating activities. Revenue is recognized over time as the performance obligations of delivering energy to customers are satisfied. To the extent that deliveries have occurred but a bill has not been issued, the Registrants accrue and recognize, as Accrued Unbilled Revenues on the balance sheets, an estimate of the revenues for energy delivered since the last billing. AEP Credit factors accounts receivable on a daily basis, excluding receivables from risk management activities, through purchase agreements with I&M, KGPCo, KPCo, OPCo, PSO, SWEPCo and a portion of APCo. Since APCo does not have regulatory authority to sell accounts receivable in its West Virginia regulatory jurisdiction, only a portion of APCo’s accounts receivable are sold to AEP Credit. AEP Credit has a receivables securitization agreement with bank conduits. Under the securitization agreement, AEP Credit receives financing from bank conduits for the interest in the billed and unbilled receivables they acquire from affiliated utility subsidiaries. See “Securitized Accounts Receivable – AEP Credit” section of Note 14 for additional information. Allowance for Uncollectible Accounts Generally, AEP Credit records bad debt expense based upon a 12-month rolling average of bad debt write-offs in proportion to gross accounts receivable purchased from participating AEP subsidiaries. For receivables related to APCo’s West Virginia operations, the bad debt reserve is calculated based on a rolling two-year average write-off in proportion to gross accounts receivable. For customer accounts receivables relating to risk management activities, accounts receivables are reviewed for bad debt reserves at a specific counterparty level basis. For AEP Texas, bad debt reserves are calculated using the specific identification of receivable balances greater than 120 days delinquent, and for those balances less than 120 days where the collection is doubtful. For miscellaneous accounts receivable, bad debt expense is recorded for all amounts outstanding 180 days or greater at 100%, unless specifically identified. Miscellaneous accounts receivable items open less than 180 days may be reserved using specific identification for bad debt reserves. Concentrations of Credit Risk and Significant Customers (Applies to Registrant Subsidiaries) APCo, I&M, OPCo, PSO and SWEPCo do not have any significant customers that comprise 10% or more of their operating revenues. AEP Texas had significant transactions with REPs which on a combined basis account for the following percentages of Total Revenues for the years ended December 31 and Accounts Receivable – Customers as of December 31: Significant Customers of AEP Texas: Centrica, TXU Energy and Reliant Energy 2019 2018 2017 (a) Percentage of Total Revenues 48 % 45 % 35 % Percentage of Accounts Receivable – Customers 43 % 35 % 31 % (a) TXU Energy did not meet the Total Revenue threshold of 10% in order to be considered a significant customer. AEPTCo had significant transactions with AEP Subsidiaries which on a combined basis account for the following percentages of Total Revenues for the years ended December 31 and Total Accounts Receivable as of December 31: Significant Customers of AEPTCo: AEP Subsidiaries 2019 2018 2017 Percentage of Total Revenues 79 % 77 % 80 % Percentage of Total Accounts Receivable 78 % 84 % 85 % The Registrant Subsidiaries monitor credit levels and the financial condition of their customers on a continuous basis to minimize credit risk. The regulatory commissions allow recovery in rates for a reasonable level of bad debt costs. Management believes adequate provisions for credit loss have been made in the accompanying Registrant Subsidiary financial statements. Renewable Energy Credits (Applies to all Registrants except AEP Texas and AEPTCo) In regulated jurisdictions, the Registrants record renewable energy credits (RECs) at cost. For AEP’s competitive generation business, management records RECs at the lower of cost or market. The Registrants follow the inventory model for these RECs. RECs expected to be consumed within one year are reported in Materials and Supplies on the balance sheets. RECs with expected consumption beyond one year are included in Deferred Charges and Other Noncurrent Assets on the balance sheets. The purchases and sales of RECs are reported in the Operating Activities section of the statements of cash flows. RECs are consumed to meet applicable state renewable portfolio standards and are recorded in Fuel and Other Consumables Used for Electric Generation at an average cost on the statements of income. The net margin on sales of RECs affects the determination of deferred fuel and REC costs and the amortization of regulatory assets for certain jurisdictions. Property, Plant and Equipment Regulated Electric utility property, plant and equipment for rate-regulated operations are stated at original cost. Additions, major replacements and betterments are added to the plant accounts. Under the group composite method of depreciation, continuous interim routine replacements of items such as boiler tubes, pumps, motors, etc. result in original cost retirements, less salvage, being charged to accumulated depreciation. The group composite method of depreciation assumes that on average, asset components are retired at the end of their useful lives and thus there is no gain or loss. The equipment in each primary electric plant account is identified as a separate group. The depreciation rates that are established take into account the past history of interim capital replacements and the amount of removal cost incurred and salvage received. These rates and the related lives are subject to periodic review. Removal costs accrued are typically recorded as regulatory liabilities when the revenue received for removal costs accrued exceeds actual removal costs incurred. The asset removal costs liability is relieved as removal costs are incurred. A regulatory asset balance will occur if actual removal costs incurred exceed accumulated removal costs accrued. The costs of labor, materials and overhead incurred to operate and maintain plant and equipment are included in operating expenses. Nuclear fuel, including nuclear fuel in the fabrication phase, is included in Other Property, Plant and Equipment on the balance sheets. Long-lived assets are required to be tested for impairment when it is determined that the carrying value of the assets may no longer be recoverable or when the assets meet the held-for-sale criteria under the accounting guidance for “Impairment or Disposal of Long-Lived Assets.” When it becomes probable that an asset in-service or an asset under construction will be abandoned and regulatory cost recovery has been disallowed or is not probable, the cost of that asset shall be removed from plant-in-service or CWIP and charged to expense. The fair value of an asset is the amount at which that asset could be bought or sold in a current transaction between willing parties, as opposed to a forced or liquidation sale. Quoted market prices in active markets are the best evidence of fair value and are used as the basis for the measurement, if available. In the absence of quoted prices for identical or similar assets in active markets, fair value is estimated using various internal and external valuation methods including cash flow analysis and appraisals. Nonregulated Nonregulated operations generally follow the policies of rate-regulated operations listed above but with the following exceptions. Property, plant and equipment of nonregulated operations are stated at original cost (or as adjusted for any applicable impairments) plus the original cost of property acquired or constructed since the acquisition, less disposals. Normal and routine retirements from the plant accounts, net of salvage, are charged to accumulated depreciation for most nonregulated operations under the group composite method of depreciation. A gain or loss would be recorded if the retirement is not considered an interim routine replacement. Removal costs are charged to expense. Allowance for Funds Used During Construction and Interest Capitalization For regulated operations, AFUDC represents the estimated cost of borrowed and equity funds used to finance construction projects that is capitalized and recovered through depreciation over the service life of regulated electric utility plant. The Registrants record the equity component of AFUDC in Allowance for Equity Funds Used During Construction and the debt component of AFUDC as a reduction to Interest Expense. For nonregulated operations, including certain generating assets, interest is capitalized during construction in accordance with the accounting guidance for “Capitalization of Interest.” Valuation of Nonderivative Financial Instruments The book values of Cash and Cash Equivalents, Advances to/from Affiliates, Accounts Receivable, Accounts Payable and Short-term Debt approximate fair value because of the short-term maturity of these instruments. Fair Value Measurements of Assets and Liabilities (Applies to all Registrants except AEPTCo) The accounting guidance for “Fair Value Measurements and Disclosures” establishes a fair value hierarchy that prioritizes the inputs used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurement) and the lowest priority to unobservable inputs (Level 3 measurement). Where observable inputs are available for substantially the full term of the asset or liability, the instrument is categorized in Level 2. When quoted market prices are not available, pricing may be completed using comparable securities, dealer values, operating data and general market conditions to determine fair value. Valuation models utilize various inputs such as commodity, interest rate and, to a lesser degree, volatility and credit that include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in inactive markets, market corroborated inputs (i.e. inputs derived principally from, or correlated to, observable market data) and other observable inputs for the asset or liability. For commercial activities, exchange-traded derivatives, namely futures contracts, are generally fair valued based on unadjusted quoted prices in active markets and are classified as Level 1. Level 2 inputs primarily consist of OTC broker quotes in moderately active or less active markets, as well as exchange-traded derivatives where there is insufficient market liquidity to warrant inclusion in Level 1. Management verifies price curves using these broker quotes and classifies these fair values within Level 2 when substantially all of the fair value can be corroborated. Management typically obtains multiple broker quotes, which are nonbinding in nature but are based on recent trades in the marketplace. When multiple broker quotes are obtained, the quoted bid and ask prices are averaged. In certain circumstances, a broker quote may be discarded if it is a clear outlier. Management uses a historical correlation analysis between the broker quoted location and the illiquid locations. If the points are highly correlated, these locations are included within Level 2 as well. Certain OTC and bilaterally executed derivative instruments are executed in less active markets with a lower availability of pricing information. Illiquid transactions, complex structured transactions, FTRs and counterparty credit risk may require nonmarket-based inputs. Some of these inputs may be internally developed or extrapolated and utilized to estimate fair value. When such inputs have a significant impact on the measurement of fair value, the instrument is categorized as Level 3. The main driver of contracts being classified as Level 3 is the inability to substantiate energy price curves in the market. A portion of the Level 3 instruments have been economically hedged which limits potential earnings volatility. AEP utilizes its trustee’s external pricing service to estimate the fair value of the underlying investments held in the benefit plan and nuclear trusts. AEP’s investment managers review and validate the prices utilized by the trustee to determine fair value. AEP’s management performs its own valuation testing to verify the fair values of the securities. AEP receives audit reports of the trustee’s operating controls and valuation processes. Assets in the benefits and nuclear trusts, cash and cash equivalents, other temporary investments and restricted cash for securitized funding are classified using the following methods. Equities are classified as Level 1 holdings if they are actively traded on exchanges. Items classified as Level 1 are investments in money market funds, fixed income and equity mutual funds and equity securities. They are valued based on observable inputs, primarily unadjusted quoted prices in active markets for identical assets. Items classified as Level 2 are primarily investments in individual fixed income securities. Fixed income securities generally do not trade on exchanges and do not have an official closing price but their valuation inputs are based on observable market data. Pricing vendors calculate bond valuations using financial models and matrices. The models use observable inputs including yields on benchmark securities, quotes by securities brokers, rating agency actions, discounts or premiums on securities compared to par prices, changes in yields for U.S. Treasury securities, corporate actions by bond issuers, prepayment schedules and histories, economic events and, for certain securities, adjustments to yields to reflect changes in the rate of inflation. Other securities with model-derived valuation inputs that are observable are also classified as Level 2 investments. Investments with unobservable valuation inputs are classified as Level 3 investments. Investments classified as Other are valued using Net Asset Value as a practical expedient. Items classified as Other are primarily cash equivalent funds, common collective trusts, commingled funds, structured products, private equity, real estate, infrastructure and alternative credit investments. These investments do not have a readily determinable fair value or they contain redemption restrictions which may include the right to suspend redemptions under certain circumstances. Redemption restrictions may also prevent certain investments from being redeemed at the reporting date for the underlying value. Deferred Fuel Costs (Applies to all Registrants except AEP Texas and AEPTCo) The cost of fuel and related emission allowances and emission control chemicals/consumables is charged to Fuel and Other Consumables Used for Electric Generation expense when the fuel is burned or the allowance or consumable is utilized. The cost of fuel also includes the cost of nuclear fuel burned which is computed primarily using the units-of-production method. In regulated jurisdictions with an active FAC, fuel cost over-recoveries (the excess of fuel-related revenues over applicable fuel costs incurred) are generally deferred as current regulatory liabilities and under-recoveries (the excess of applicable fuel costs incurred over fuel-related revenues) are generally deferred as current regulatory assets. Fuel cost over-recovery and under-recovery balances are classified as noncurrent when there is a commission-approved plan to delay refunds or recoveries beyond a one year period. These deferrals are amortized when refunded or when billed to customers in later months with the state regulatory commissions’ review and approval. The amount of an over-recovery or under-recovery can also be affected by actions of the state regulatory commissions. On a routine basis, state regulatory commissions review and/or audit the Registrants’ fuel procurement policies and practices, the fuel cost calculations and FAC deferrals. FAC deferrals are adjusted when costs are no longer probable of recovery or when refunds of fuel reserves are probable. Changes in fuel costs, including purchased power in Kentucky for KPCo, Indiana and Michigan for I&M, in Arkansas, Louisiana and Texas for SWEPCo, in Oklahoma for PSO, in Virginia and West Virginia for APCo and in West Virginia for WPCo are reflected in rates in a timely manner generally through the FAC. In Ohio, purchased power is reflected in rates through various PUCO approved mechanisms. The FAC generally includes some sharing of off-system sales margins. In West Virginia for APCo and WPCo, all of the non-merchant margins from off-system sales are given to customers through the FAC. A portion of margins from off-system sales are given to customers through the FAC and other rate mechanisms in Oklahoma for PSO, Arkansas, Louisiana and Texas for SWEPCo, Kentucky for KPCo, Virginia for APCo and in Indiana and Michigan for I&M. Beginning in 2020, Arkansas for SWEPCo will start giving all margins from off-system sales to customers through the FAC. Where the FAC or off-system sales sharing mechanism is capped, frozen or non-existent, changes in fuel costs or sharing of off-system sales impact earnings. Revenue Recognition Regulatory Accounting The Registrants’ financial statements reflect the actions of regulators that can result in the recognition of revenues and expenses in different time periods than enterprises that are not rate-regulated. Regulatory assets (deferred expenses or alternative revenues recognized in accordance with the guidance for “Regulated Operations”) and regulatory liabilities (deferred revenue reductions or refunds) are recorded to reflect the economic effects of regulation in the same accounting period by matching expenses with their recovery through regulated revenues and by matching revenue with its passage to customers in cost-based regulated rates. When regulatory assets are probable of recovery through regulated rates, assets are recorded on the balance sheets. Regulatory assets are tested for probability of recovery at each balance sheet date or whenever new events occur. Examples of new events include the issuance of a regulatory commission order or passage of new legislation. If it is determined that recovery of a regulatory asset is no longer probable, the regulatory asset is derecognized as a charge against income. Retail and Wholesale Supply and Delivery of Electricity The Registrants recognize revenues from customers for retail and wholesale electricity sales and electricity transmission and distribution delivery services. The Registrants recognize such revenues on the statements of income as the performance obligations of delivering energy to customers are satisfied. Recognized revenues include both billed and unbilled amounts. In accordance with the applicable state commission’s regulatory treatment, PSO and SWEPCo do not include the fuel portion in unbilled revenue, but rather recognize such revenues when billed to customers. Wholesale transmission revenue is based on FERC approved formula rate filings made for each calendar year using estimated costs. Revenues initially recognized per the annual rate filing are compared to actual costs, resulting in the subsequent recognition of an over or under recovered amount, with interest, that is refunded or recovered, respectively, in a future year’s rates. These annual true-ups meet the definition of alternative revenues in accordance with the accounting guidance for “Regulated Operations”, and are recognized by the Registrants in the second quarter of each calendar year following the filing of annual FERC reports. Any portion of the true-ups applicable to an affiliated company is recorded as Accounts Receivable - Affiliated Companies or Accounts Payable - Affiliated Companies on the balance sheets. Any portion of the true-ups applicable to third-parties is recorded as Regulatory Assets or Regulatory Liabilities on the balance sheets. See Note 20 - Revenue from Contracts with Customers for additional information. Gross versus Net Presentation of Certain Electricity Supply and Delivery Activities Most of the power produced at the generation plants is sold to PJM or SPP. The Registrants also purchase power from PJM and SPP to supply power to customers. Generally, these power sales and purchases are reported on a net basis as revenues on the statements of income. However, purchases of power in excess of sales to PJM or SPP, on an hourly net basis, used to serve retail load are recorded gross as Purchased Electricity for Resale on the statements of income. With the exception of certain dedicated load bilateral power supply contracts, the transactions of AEP’s nonregulated subsidiaries are reported as gross purchases or sales. Physical energy purchases arising from non-derivative contracts are accounted for on a gross basis in Purchased Electricity for Resale on the statements of income. Energy purchases arising from non-trading derivative contracts are recorded based on the transaction’s facts and circumstances. Purchases under non-trading derivatives used to serve accrual based obligations are recorded in Purchased Electricity for Resale on the statements of income. All other non-trading derivative purchases are recorded net in revenues. In general, the Registrants record expenses when purchased electricity is received and when expenses are incurred, with the exception of certain power purchase contracts that are derivatives and accounted for using MTM accounting where generation/supply rates are not cost-based regulated. In jurisdictions where the generation/supply business is subject to cost-based regulation, the unrealized MTM amounts are deferred as regulatory assets (for losses) and regulatory liabil

New Accounting Pronouncements

New Accounting Pronouncements	12 Months Ended
	Dec. 31, 2019
New Accounting Pronouncements	2 . NEW ACCOUNTING STANDARDS The disclosures in this note apply to all Registrants unless indicated otherwise. During the FASB’s standard-setting process and upon issuance of final standards, management reviews the new accounting literature to determine its relevance, if any, to the Registrants’ business. The following standards will impact the financial statements. ASU 2016-02 “Accounting for Leases” (ASU 2016-02) In February 2016, the FASB issued ASU 2016-02 increasing the transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheets and disclosing key information about leasing arrangements. Under the new standard, an entity must recognize an asset and liability for operating leases on the balance sheets. Additionally, capital leases are known as finance leases going forward. Leases with terms of 12 months or longer are also subject to the new requirements. Fundamentally, the criteria used to determine lease classification remains the same, but is more subjective under the new standard. New leasing standard implementation activities included the identification of the lease population within the AEP System as well as the sampling of representative lease contracts to analyze accounting treatment under the new accounting guidance. Based upon the completed assessments, management also prepared a gap analysis to outline new disclosure compliance requirements. Management adopted ASU 2016-02 effective January 1, 2019 by means of a cumulative-effect adjustment to the balance sheets. Management elected the following practical expedients upon adoption: Practical Expedient Description Overall Expedients (for leases commenced prior to adoption date and must be adopted as a package) Do not need to reassess whether any expired or existing contracts are/or contain leases, do not need to reassess the lease classification for any expired or existing leases and do not need to reassess initial direct costs for any existing leases. Lease and Non-lease Components (elect by class of underlying asset) Elect as an accounting policy to not separate non-lease components from lease components and instead account for each lease and associated non-lease component as a single lease component. Short-term Lease (elect by class of underlying asset) Elect as an accounting policy to not apply the recognition requirements to short-term leases. Existing and expired land easements not previously accounted for as leases Elect optional transition practical expedient to not evaluate under Topic 842 existing or expired land easements that were not previously accounted for as leases under the current leases guidance in Topic 840. Cumulative-effect adjustment in the period of adoption Elect the optional transition practical expedient to adopt the new lease requirements through a cumulative-effect adjustment on the balance sheets in the period of adoption. Management concluded that the result of adoption would not materially change the volume of contracts that qualify as leases going forward. The adoption of the new standard did not materially impact results of operations or cash flows, but did have a material impact on the balance sheets. See Note 13 - Leases for additional disclosures required by the new standard. ASU 2016-13 “Measurement of Credit Losses on Financial Instruments” (ASU 2016-13) In June 2016, the FASB issued ASU 2016-13 requiring the recognition of an allowance for expected credit losses for financial instruments within its scope. Examples of financial instruments that are in scope include trade receivables, certain financial guarantees, and held-to-maturity debt securities. The allowance for expected credit losses should be based on historical information, current conditions and reasonable and supportable forecasts. Entities are required to evaluate, and if necessary, recognize expected credit losses at the inception or initial acquisition of a financial instrument (or pool of financial instruments that share similar risk characteristics) subject to ASU 2016-13, and subsequently as of each reporting date. The new standard also revises the other-than-temporary impairment model for available-for-sale debt securities. Management adopted ASU 2016-13 and its related implementation guidance effective January 1, 2020, by means of a cumulative-effect adjustment to the balance sheets. The adoption of the new standard did not have a material impact to financial position, and had no impact on the results of operations or cash flows. Additionally, the adoption of the new standard did not result in any changes to current accounting systems. Implementation activities included: (1) the identification and evaluation of the population of financial instruments within the AEP system that are subject to the new standard and, (2) the development of supporting valuation models to also contemplate appropriate metrics for current and supportable forecasted information. As required by ASU 2016-13, the financial instruments subject to the new standard were evaluated on a pool-basis to the extent such financial instruments shared similar risk characteristics.

Comprehensive Income

Comprehensive Income	12 Months Ended
	Dec. 31, 2019
Comprehensive Income	COMPREHENSIVE INCOME The disclosures in this note apply to all Registrants except for AEPTCo. AEPTCo does not have any components of other comprehensive income for any period presented in the financial statements. Presentation of Comprehensive Income The following tables provide the components of changes in AOCI and details of reclassifications from AOCI for the years ended December 31, 2019 , 2018 and 2017 . The amortization of pension and OPEB AOCI components are included in the computation of net periodic pension and OPEB costs. See Note 8 - Benefit Plans for additional details. AEP Cash Flow Hedges Pension and OPEB For the Year Ended December 31, 2019 Commodity Interest Rate Amortization of Deferred Costs Changes in Funded Status Total (in millions) Balance in AOCI as of December 31, 2018 $ (23.0 ) $ (12.6 ) $ 136.3 $ (221.1 ) $ (120.4 ) Change in Fair Value Recognized in AOCI (127.2 ) (0.2 ) (a) — 57.7 (69.7 ) Amount of (Gain) Loss Reclassified from AOCI Generation & Marketing Revenues (b) (0.2 ) — — — (0.2 ) Purchased Electricity for Resale (b) 59.5 — — — 59.5 Interest Expense (b) — 1.5 — — 1.5 Amortization of Prior Service Cost (Credit) — — (19.2 ) — (19.2 ) Amortization of Actuarial (Gains) Losses — — 12.1 — 12.1 Reclassifications from AOCI, before Income Tax (Expense) Benefit 59.3 1.5 (7.1 ) — 53.7 Income Tax (Expense) Benefit 12.6 0.2 (1.5 ) — 11.3 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 46.7 1.3 (5.6 ) — 42.4 Net Current Period Other Comprehensive Income (Loss) (80.5 ) 1.1 (5.6 ) 57.7 (27.3 ) Balance in AOCI as of December 31, 2019 $ (103.5 ) $ (11.5 ) $ 130.7 $ (163.4 ) $ (147.7 ) AEP Cash Flow Hedges Pension and OPEB For the Year Ended December 31, 2018 Commodity Interest Rate Securities Available for Sale Amortization of Deferred Costs Changes in Funded Status Total (in millions) Balance in AOCI as of December 31, 2017 $ (28.4 ) $ (13.0 ) $ 11.9 $ 141.6 $ (179.9 ) $ (67.8 ) Change in Fair Value Recognized in AOCI 37.3 2.3 — — (33.0 ) 6.6 Amount of (Gain) Loss Reclassified from AOCI Generation & Marketing Revenues (b) (0.1 ) — — — — (0.1 ) Purchased Electricity for Resale (b) (32.6 ) — — — — (32.6 ) Interest Expense (b) — 1.1 — — — 1.1 Amortization of Prior Service Cost (Credit) — — — (19.5 ) — (19.5 ) Amortization of Actuarial (Gains) Losses — — — 12.8 — 12.8 Reclassifications from AOCI, before Income Tax (Expense) Benefit (32.7 ) 1.1 — (6.7 ) — (38.3 ) Income Tax (Expense) Benefit (6.9 ) 0.3 — (1.4 ) — (8.0 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (25.8 ) 0.8 — (5.3 ) — (30.3 ) Net Current Period Other Comprehensive Income (Loss) 11.5 3.1 — (5.3 ) (33.0 ) (23.7 ) ASU 2018-02 Adoption (6.1 ) (2.7 ) — — (8.2 ) (17.0 ) ASU 2016-01 Adoption — — (11.9 ) — — (11.9 ) Balance in AOCI as of December 31, 2018 $ (23.0 ) $ (12.6 ) $ — $ 136.3 $ (221.1 ) $ (120.4 ) Cash Flow Hedges Pension and OPEB For the Year Ended December 31, 2017 Commodity Interest Rate Securities Available for Sale Amortization of Deferred Costs Changes in Funded Status Total (in millions) Balance in AOCI as of December 31, 2016 $ (23.1 ) $ (15.7 ) $ 8.4 $ 140.5 $ (266.4 ) $ (156.3 ) Change in Fair Value Recognized in AOCI (20.4 ) 1.6 3.5 — 86.5 71.2 Amount of (Gain) Loss Reclassified from AOCI Generation & Marketing Revenues (b) (5.6 ) — — — — (5.6 ) Purchased Electricity for Resale (b) 28.8 — — — — 28.8 Interest Expense (b) — 1.5 — — — 1.5 Amortization of Prior Service Cost (Credit) — — — (19.6 ) — (19.6 ) Amortization of Actuarial (Gains) Losses — — — 21.3 — 21.3 Reclassifications from AOCI, before Income Tax (Expense) Benefit 23.2 1.5 — 1.7 — 26.4 Income Tax (Expense) Benefit 8.1 0.4 — 0.6 — 9.1 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 15.1 1.1 — 1.1 — 17.3 Net Current Period Other Comprehensive Income (Loss) (5.3 ) 2.7 3.5 1.1 86.5 88.5 Balance in AOCI as of December 31, 2017 $ (28.4 ) $ (13.0 ) $ 11.9 $ 141.6 $ (179.9 ) $ (67.8 ) AEP Texas Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2019 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2018 $ (4.4 ) $ 4.7 $ (15.4 ) $ (15.1 ) Change in Fair Value Recognized in AOCI — — 1.1 1.1 Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 1.3 — — 1.3 Amortization of Prior Service Cost (Credit) — (0.1 ) — (0.1 ) Amortization of Actuarial (Gains) Losses — 0.3 — 0.3 Reclassifications from AOCI, before Income Tax (Expense) Benefit 1.3 0.2 — 1.5 Income Tax (Expense) Benefit 0.3 — — 0.3 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 1.0 0.2 — 1.2 Net Current Period Other Comprehensive Income (Loss) 1.0 0.2 1.1 2.3 Balance in AOCI as of December 31, 2019 $ (3.4 ) $ 4.9 $ (14.3 ) $ (12.8 ) Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2018 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2017 $ (4.5 ) $ 4.5 $ (12.6 ) $ (12.6 ) Change in Fair Value Recognized in AOCI — — (1.0 ) (1.0 ) Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 1.3 — — 1.3 Amortization of Prior Service Cost (Credit) — (0.1 ) — (0.1 ) Amortization of Actuarial (Gains) Losses — 0.4 — 0.4 Reclassifications from AOCI, before Income Tax (Expense) Benefit 1.3 0.3 — 1.6 Income Tax (Expense) Benefit 0.3 0.1 — 0.4 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 1.0 0.2 — 1.2 Net Current Period Other Comprehensive Income (Loss) 1.0 0.2 (1.0 ) 0.2 ASU 2018-02 Adoption (0.9 ) — (1.8 ) (2.7 ) Balance in AOCI as of December 31, 2018 $ (4.4 ) $ 4.7 $ (15.4 ) $ (15.1 ) Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2017 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2016 $ (5.4 ) $ 4.2 $ (13.7 ) $ (14.9 ) Change in Fair Value Recognized in AOCI — — 1.1 1.1 Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 1.3 — — 1.3 Amortization of Prior Service Cost (Credit) — (0.1 ) — (0.1 ) Amortization of Actuarial (Gains) Losses — 0.5 — 0.5 Reclassifications from AOCI, before Income Tax (Expense) Benefit 1.3 0.4 — 1.7 Income Tax (Expense) Benefit 0.4 0.1 — 0.5 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 0.9 0.3 — 1.2 Net Current Period Other Comprehensive Income (Loss) 0.9 0.3 1.1 2.3 Balance in AOCI as of December 31, 2017 $ (4.5 ) $ 4.5 $ (12.6 ) $ (12.6 ) APCo Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2019 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2018 $ 1.8 $ 11.7 $ (18.5 ) $ (5.0 ) Change in Fair Value Recognized in AOCI — — 13.4 13.4 Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (1.1 ) — — (1.1 ) Amortization of Prior Service Cost (Credit) — (5.3 ) — (5.3 ) Amortization of Actuarial (Gains) Losses — 2.1 — 2.1 Reclassifications from AOCI, before Income Tax (Expense) Benefit (1.1 ) (3.2 ) — (4.3 ) Income Tax (Expense) Benefit (0.2 ) (0.7 ) — (0.9 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (0.9 ) (2.5 ) — (3.4 ) Net Current Period Other Comprehensive Income (Loss) (0.9 ) (2.5 ) 13.4 10.0 Balance in AOCI as of December 31, 2019 $ 0.9 $ 9.2 $ (5.1 ) $ 5.0 Pension and OPEB Cash Flow Hedges Amortization Changes in Interest of Deferred Funded For the Year Ended December 31, 2018 Commodity Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2017 $ — $ 2.2 $ 14.8 $ (15.7 ) $ 1.3 Change in Fair Value Recognized in AOCI (0.7 ) — — (2.6 ) (3.3 ) Amount of (Gain) Loss Reclassified from AOCI Purchased Electricity for Resale (b) 0.9 — — — 0.9 Interest Expense (b) — (1.1 ) — — (1.1 ) Amortization of Prior Service Cost (Credit) — — (5.2 ) — (5.2 ) Amortization of Actuarial (Gains) Losses — — 1.3 — 1.3 Reclassifications from AOCI, before Income Tax (Expense) Benefit 0.9 (1.1 ) (3.9 ) — (4.1 ) Income Tax (Expense) Benefit 0.2 (0.2 ) (0.8 ) — (0.8 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 0.7 (0.9 ) (3.1 ) — (3.3 ) Net Current Period Other Comprehensive Income (Loss) — (0.9 ) (3.1 ) (2.6 ) (6.6 ) ASU 2018-02 Adoption — 0.5 — (0.2 ) 0.3 Balance in AOCI as of December 31, 2018 $ — $ 1.8 $ 11.7 $ (18.5 ) $ (5.0 ) Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2017 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2016 $ 2.9 $ 16.0 $ (27.3 ) $ (8.4 ) Change in Fair Value Recognized in AOCI — — 11.6 11.6 Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (1.1 ) — — (1.1 ) Amortization of Prior Service Cost (Credit) — (5.2 ) — (5.2 ) Amortization of Actuarial (Gains) Losses — 3.4 — 3.4 Reclassifications from AOCI, before Income Tax (Expense) Benefit (1.1 ) (1.8 ) — (2.9 ) Income Tax (Expense) Benefit (0.4 ) (0.6 ) — (1.0 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (0.7 ) (1.2 ) — (1.9 ) Net Current Period Other Comprehensive Income (Loss) (0.7 ) (1.2 ) 11.6 9.7 Balance in AOCI as of December 31, 2017 $ 2.2 $ 14.8 $ (15.7 ) $ 1.3 I&M Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2019 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2018 $ (11.5 ) $ 5.1 $ (7.4 ) $ (13.8 ) Change in Fair Value Recognized in AOCI — — 0.8 0.8 Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 2.0 — — 2.0 Amortization of Prior Service Cost (Credit) — (0.8 ) — (0.8 ) Amortization of Actuarial (Gains) Losses — 0.6 — 0.6 Reclassifications from AOCI, before Income Tax (Expense) Benefit 2.0 (0.2 ) — 1.8 Income Tax (Expense) Benefit 0.4 — — 0.4 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 1.6 (0.2 ) — 1.4 Net Current Period Other Comprehensive Income (Loss) 1.6 (0.2 ) 0.8 2.2 Balance in AOCI as of December 31, 2019 $ (9.9 ) $ 4.9 $ (6.6 ) $ (11.6 ) Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2018 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2017 $ (10.7 ) $ 5.1 $ (6.5 ) $ (12.1 ) Change in Fair Value Recognized in AOCI — — (0.6 ) (0.6 ) Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 2.0 — — 2.0 Amortization of Prior Service Cost (Credit) — (0.8 ) — (0.8 ) Amortization of Actuarial (Gains) Losses — 0.8 — 0.8 Reclassifications from AOCI, before Income Tax (Expense) Benefit 2.0 — — 2.0 Income Tax (Expense) Benefit 0.4 — — 0.4 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 1.6 — — 1.6 Net Current Period Other Comprehensive Income (Loss) 1.6 — (0.6 ) 1.0 ASU 2018-02 Adoption (2.4 ) — (0.3 ) (2.7 ) Balance in AOCI as of December 31, 2018 $ (11.5 ) $ 5.1 $ (7.4 ) $ (13.8 ) Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2017 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2016 $ (12.0 ) $ 5.1 $ (9.3 ) $ (16.2 ) Change in Fair Value Recognized in AOCI — — 2.8 2.8 Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 2.0 — — 2.0 Amortization of Prior Service Cost (Credit) — (0.9 ) — (0.9 ) Amortization of Actuarial (Gains) Losses — 0.9 — 0.9 Reclassifications from AOCI, before Income Tax (Expense) Benefit 2.0 — — 2.0 Income Tax (Expense) Benefit 0.7 — — 0.7 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 1.3 — — 1.3 Net Current Period Other Comprehensive Income (Loss) 1.3 — 2.8 4.1 Balance in AOCI as of December 31, 2017 $ (10.7 ) $ 5.1 $ (6.5 ) $ (12.1 ) OPCo Cash Flow Hedge – For the Year Ended December 31, 2019 Interest Rate (in millions) Balance in AOCI as of December 31, 2018 $ 1.0 Change in Fair Value Recognized in AOCI — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (1.3 ) Reclassifications from AOCI, before Income Tax (Expense) Benefit (1.3 ) Income Tax (Expense) Benefit (0.3 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (1.0 ) Net Current Period Other Comprehensive Income (Loss) (1.0 ) Balance in AOCI as of December 31, 2019 $ — Cash Flow Hedge – For the Year Ended December 31, 2018 Interest Rate (in millions) Balance in AOCI as of December 31, 2017 $ 1.9 Change in Fair Value Recognized in AOCI — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (1.7 ) Reclassifications from AOCI, before Income Tax (Expense) Benefit (1.7 ) Income Tax (Expense) Benefit (0.4 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (1.3 ) Net Current Period Other Comprehensive Income (Loss) (1.3 ) ASU 2018-02 Adoption 0.4 Balance in AOCI as of December 31, 2018 $ 1.0 Cash Flow Hedge – For the Year Ended December 31, 2017 Interest Rate (in millions) Balance in AOCI as of December 31, 2016 $ 3.0 Change in Fair Value Recognized in AOCI — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (1.7 ) Reclassifications from AOCI, before Income Tax (Expense) Benefit (1.7 ) Income Tax (Expense) Benefit (0.6 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (1.1 ) Net Current Period Other Comprehensive Income (Loss) (1.1 ) Balance in AOCI as of December 31, 2017 $ 1.9 PSO Cash Flow Hedge – For the Year Ended December 31, 2019 Interest Rate (in millions) Balance in AOCI as of December 31, 2018 $ 2.1 Change in Fair Value Recognized in AOCI — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (1.3 ) Reclassifications from AOCI, before Income Tax (Expense) Benefit (1.3 ) Income Tax (Expense) Benefit (0.3 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (1.0 ) Net Current Period Other Comprehensive Income (Loss) (1.0 ) Balance in AOCI as of December 31, 2019 $ 1.1 Cash Flow Hedge – For the Year Ended December 31, 2018 Interest Rate (in millions) Balance in AOCI as of December 31, 2017 $ 2.6 Change in Fair Value Recognized in AOCI — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (1.3 ) Reclassifications from AOCI, before Income Tax (Expense) Benefit (1.3 ) Income Tax (Expense) Benefit (0.3 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (1.0 ) Net Current Period Other Comprehensive Income (Loss) (1.0 ) ASU 2018-02 Adoption 0.5 Balance in AOCI as of December 31, 2018 $ 2.1 Cash Flow Hedge – For the Year Ended December 31, 2017 Interest Rate (in millions) Balance in AOCI as of December 31, 2016 $ 3.4 Change in Fair Value Recognized in AOCI — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (1.3 ) Reclassifications from AOCI, before Income Tax (Expense) Benefit (1.3 ) Income Tax (Expense) Benefit (0.5 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (0.8 ) Net Current Period Other Comprehensive Income (Loss) (0.8 ) Balance in AOCI as of December 31, 2017 $ 2.6 SWEPCo Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2019 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2018 $ (3.3 ) $ (0.2 ) $ (1.9 ) $ (5.4 ) Change in Fair Value Recognized in AOCI — — 3.7 3.7 Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 1.9 — — 1.9 Amortization of Prior Service Cost (Credit) — (2.0 ) — (2.0 ) Amortization of Actuarial (Gains) Losses — 0.6 — 0.6 Reclassifications from AOCI, before Income Tax (Expense) Benefit 1.9 (1.4 ) — 0.5 Income Tax (Expense) Benefit 0.4 (0.3 ) — 0.1 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 1.5 (1.1 ) — 0.4 Net Current Period Other Comprehensive Income (Loss) 1.5 (1.1 ) 3.7 4.1 Balance in AOCI as of December 31, 2019 $ (1.8 ) $ (1.3 ) $ 1.8 $ (1.3 ) Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2018 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2017 $ (6.0 ) $ 1.2 $ 0.8 $ (4.0 ) Change in Fair Value Recognized in AOCI 2.3 — (3.1 ) (0.8 ) Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 2.1 — — 2.1 Amortization of Prior Service Cost (Credit) — (2.0 ) — (2.0 ) Amortization of Actuarial (Gains) Losses — 0.2 — 0.2 Reclassifications from AOCI, before Income Tax (Expense) Benefit 2.1 (1.8 ) — 0.3 Income Tax (Expense) Benefit 0.4 (0.4 ) — — Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 1.7 (1.4 ) — 0.3 Net Current Period Other Comprehensive Income (Loss) 4.0 (1.4 ) (3.1 ) (0.5 ) ASU 2018-02 Adoption (1.3 ) — 0.4 (0.9 ) Balance in AOCI as of December 31, 2018 $ (3.3 ) $ (0.2 ) $ (1.9 ) $ (5.4 ) Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2017 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2016 $ (7.4 ) $ 1.9 $ (3.9 ) $ (9.4 ) Change in Fair Value Recognized in AOCI — — 4.7 4.7 Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 2.2 — — 2.2 Amortization of Prior Service Cost (Credit) — (2.0 ) — (2.0 ) Amortization of Actuarial (Gains) Losses — 0.9 — 0.9 Reclassifications from AOCI, before Income Tax (Expense) Benefit 2.2 (1.1 ) — 1.1 Income Tax (Expense) Benefit 0.8 (0.4 ) — 0.4 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 1.4 (0.7 ) — 0.7 Net Current Period Other Comprehensive Income (Loss) 1.4 (0.7 ) 4.7 5.4 Balance in AOCI as of December 31, 2017 $ (6.0 ) $ 1.2 $ 0.8 $ (4.0 ) (a) The change in fair value includes $4 million related to AEP's investment in joint venture wind farms acquired as part of the purchase of Sempra Renewables LLC for the year ended December 31, 2019. See “Sempra Renewables LLC” section of Note 17 for additional information. (b) Amounts reclassified to the referenced line item on the statements of income.

Rate Matters

Rate Matters	12 Months Ended
	Dec. 31, 2019
Rate Matters	RATE MATTERS The disclosures in this note apply to all Registrants unless indicated otherwise. The Registrants are involved in rate and regulatory proceedings at the FERC and their state commissions. Rate matters can have a material impact on net income, cash flows and possibly financial condition. The Registrants’ recent significant rate orders and pending rate filings are addressed in this note. Impact of Tax Reform Rate and regulatory matters are impacted by federal income tax implications. In December 2017, Tax Reform was enacted, which impacts outstanding rate and regulatory matters. For additional details on the impact of Tax Reform, see Note 12 - Income Taxes. AEP Texas Rate Matters (Applies to AEP and AEP Texas) 2019 Texas Base Rate Case In May 2019, AEP Texas filed a request with the PUCT for a $56 million annual increase in rates based upon a proposed 10.5% return on common equity. The filing includes a proposed Income Tax Refund Rider that will refund $21 million annually of Excess ADIT that is primarily not subject to normalization requirements. The rate case also seeks a prudence determination on all transmission and distribution capital additions through 2018 included in interim rates from 2008 to December 2019. As of December 31, 2019 , AEP Texas’ cumulative revenues from transmission and distribution interim rate increases are estimated to be approximately $1.4 billion and are subject to reconciliation in this base rate case. In November 2019, ALJs issued a Proposal for Decision recommending a $60 million annual rate reduction based upon a 9.4% return on common equity. The ALJs also recommended disallowances that could potentially result in write-offs of $84 million related to capital incentives and $5 million related to other plant additions. Additionally, the ALJs recommended that AEP Texas should be required to file an application for a separate proceeding to determine if any refunds are required associated with any disallowances on distribution or transmission capital investments. In February 2020, AEP Texas, the PUCT staff and various intervenors filed a stipulation and settlement agreement with the PUCT. The agreement includes a proposed annual base rate reduction of $40 million based upon a 9.4% return on common equity with a capital structure of 57.5% debt and 42.5% common equity. The agreement provides recovery of $26 million in capitalized vegetation management expenses that were incurred through 2018. The agreement includes disallowances of $23 million related to capital investments recorded through 2018 and $4 million related to rate case expenses. In addition, AEP Texas will refund: (a) $77 million of Excess ADIT and excess federal income taxes collected as a result of Tax Reform to distribution customers over a one year period, (b) $31 million of Excess ADIT and excess federal income taxes collected as a result of Tax Reform to transmission customers as a one-time credit and (c) $30 million of previously collected rates that were subject to reconciliation in this proceeding over a one year period with no carrying costs. Per the agreement, AEP Texas is required to file its next base rate case within four years of the date of the final order. The agreement also: (a) states future financially based capital incentives will not be included in interim transmission and distribution rates, (b) contains various ring-fencing provisions and (c) will allow the PUCT to decide whether to adopt a dividend restriction ring-fencing provision. As a result of the stipulation and settlement agreement, AEP Texas (a) recorded an impairment of $33 million in December 2019 related to capital investments, which included $10 million of current year investments, in Asset Impairments and Other Related Charges on the statements of income, (b) recorded a $30 million provision for refund on the statements of income for revenues previously collected through rates and (c) wrote-off $4 million of rate case expenses to Other Operation on the statements of income. The PUCT is expected to issue an order in the first quarter of 2020. Upon approval of the 2019 Texas Base Rate Case, AEP Texas will refund $275 million of Excess ADIT associated with certain depreciable property using ARAM to transmission customers. AEP Texas will determine how to refund the remaining Excess ADIT that is not subject to normalization requirements in future proceedings. If the final order from the PUCT requires refunds or authorizes disallowances in excess of the amounts included within the February 2020 stipulation and settlement agreement, it could reduce future net income and cash flows and impact financial condition. Texas Storm Cost Securitization In August 2017, Hurricane Harvey hit the coast of Texas, causing power outages in the AEP Texas service territory. In March 2019, AEP Texas filed a request to securitize total estimated distribution-related system restoration costs with the PUCT, which included estimated carrying costs. In June 2019, the PUCT approved the financing order. As part of the financing order, AEP Texas agreed to offset $64 million of Excess ADIT that is not subject to normalization requirements against the total distribution-related system restoration costs. In September 2019, AEP Texas issued $235 million of securitization bonds. The securitization bonds included carrying costs of $33 million, which includes $21 million of debt carrying costs recorded as a reduction to Interest Expense in 2019. The stipulation and settlement agreement discussed in the 2019 Texas Base Rate Case above does not require any adjustments to the remaining $95 million of estimated net transmission-related system restoration costs and these costs will be recovered in base rates if the agreement is approved by the PUCT. If these costs are not recovered, it could have an adverse effect on future net income, cash flows and financial condition. APCo and WPCo Rate Matters (Applies to AEP and APCo) Virginia Legislation Affecting Earnings Reviews Under a 2015 amended Virginia law, APCo’s existing generation and distribution base rates were frozen until after the Virginia SCC ruled on APCo’s next biennial review. The 2015 amendments also precluded the Virginia SCC from performing biennial reviews of APCo’s earnings for the years 2014 through 2017. Further amendments to Virginia law impacting investor-owned utilities were enacted, effective July 1, 2018, that require APCo to file its next generation and distribution base rate case by March 31, 2020 using 2017, 2018 and 2019 earnings test years (triennial review). Triennial reviews are subject to an earnings test which provides that 70% of any earnings in excess of 70 basis points above APCo’s Virginia SCC authorized ROE would be refunded to customers. In such case, the Virginia SCC could also lower APCo’s Virginia retail base rates on a prospective basis. In November 2018, the Virginia SCC authorized a ROE of 9.42% applicable to APCo base rate earnings for the 2017-2019 triennial period. Virginia law provides that costs associated with asset impairments of retired coal generation assets, or automated meters, or both, which a utility records as an expense, shall be attributed to the test periods under review in a triennial review proceeding, and be deemed recovered. In 2015, APCo retired the Sporn Plant, the Kanawha River Plant, the Glen Lyn Plant, Clinch River Unit 3 and the coal portions of Clinch River Units 1 and 2 (collectively, the retired coal-fired generation assets). The net book value of these plants at the retirement date was $93 million before cost of removal, including materials and supplies inventory. Based on management’s interpretation of Virginia law and more certainty regarding APCo’s triennial revenues, expenses and resulting earnings upon reaching the end of the three-year review period, APCo recorded a pretax expense of $93 million related to its previously retired coal-fired generation assets in December 2019. This expense is included in Asset Impairments and Other Related Charges on the statements of income. As a result, management deems these costs to be substantially recovered by APCo during the triennial review period. APCo is currently in the process of retiring and replacing its Virginia jurisdictional Automated Meter Reading (AMR) meters with Advanced Metering Infrastructure (AMI) meters. As of December 31, 2019, APCo has approximately $51 million of Virginia jurisdictional AMR meters recorded in Total Property, Plant and Equipment - Net on its balance sheets. APCo intends to pursue full recovery of these assets through future depreciation rates. Inclusive of the $93 million expense associated with APCo’s Virginia jurisdictional retired coal-fired plants, APCo estimates its Virginia earnings for the triennial period to be below the authorized ROE range. If any APCo Virginia jurisdictional costs are not recoverable or refunds of revenues collected from customers during the triennial review period, it could reduce future net income and cash flows and impact financial condition. Virginia Staff Depreciation Study Request In November 2018, Virginia staff recommended that APCo implement new Virginia jurisdictional depreciation rates effective January 1, 2018 based on APCo’s depreciation study that was prepared at Virginia staff’s request using December 31, 2017 APCo property balances. Implementation of those depreciation rates would result in a $21 million pretax increase in annual depreciation expense ($6 million related to transmission) with no corresponding increase in retail base rates. In December 2018, APCo submitted a response to the Virginia staff stating that it was inappropriate for APCo to change Virginia depreciation rates in advance of the Virginia SCC’s Triennial Review of APCo’s earnings, citing the Virginia SCC’s November 2014 order to not change APCo’s Virginia depreciation rates until APCo’s next base rate case/review. If the Virginia SCC were to issue an order approving the Virginia staff’s recommended retroactive change in APCo’s Virginia depreciation rates, it would reduce future net income and cash flows and impact financial condition. Virginia Tax Reform In March 2019, the Virginia SCC issued an order to reduce APCo’s base rates to refund: (a) $40 million annually for ongoing annual tax savings, (b) $9 million annually of Excess ADIT associated with certain depreciable property using ARAM, (c) $94 million of Excess ADIT that is not subject to normalization requirements over three years and (d) a one-time credit of $22 million for estimated excess taxes collected from customers as a result of Tax Reform during the 15-month period ending March 31, 2019. 2018 West Virginia Base Rate Case In May 2018, APCo and WPCo filed a joint request with the WVPSC to increase their combined West Virginia base rates by $115 million ($98 million related to APCo) annually based on a 10.22% return on common equity. The proposed annual increase included $32 million ($28 million related to APCo) due to increased annual depreciation expense and reflected the impact of the reduction in the federal income tax rate due to Tax Reform. In October 2018, APCo and WPCo filed updated schedules supporting a $95 million ($80 million related to APCo) annual increase in West Virginia base rates primarily due to the impact of West Virginia Tax Reform. In February 2019, the WVPSC issued an order approving a stipulation and settlement agreement between APCo, WPCo, WVPSC staff and certain intervenors. The agreement included an annual base rate increase of $44 million ($36 million related to APCo) based upon a 9.75% return on common equity effective March 2019. The agreement also included: (a) $18 million ($14 million related to APCo) of increased annual depreciation expense, (b) a $24 million refund ($19 million related to APCo) over two years, through a rider beginning March 2019, of Excess ADIT that is not subject to normalization requirements, (c) the utilization of $14 million ($12 million related to APCo) of Excess ADIT that is not subject to normalization requirements to offset regulatory asset balances relating to ENEC, (d) an agreement to seek WVPSC approval of economic incentive programs to provide funds to aid in industrial and commercial development and (e) an agreement, barring any unforeseen events, to not initiate another base rate proceeding prior to April 1, 2020. ETT Rate Matters (Applies to AEP) ETT Interim Transmission Rates AEP has a 50% equity ownership interest in ETT. Predominantly all of ETT’s revenues are based on semi-annual interim rate changes which are subject to review and possible true-up in the next base rate proceeding. Through December 31, 2019 , AEP’s share of ETT’s cumulative revenues that are subject to review is estimated to be $1 billion. A base rate review could produce a refund if ETT incurs a disallowance of the transmission investment on which an interim increase was based. A revenue decrease, including a refund of interim transmission rates, could reduce future net income and cash flows and impact financial condition. Management is unable to determine a range of potential losses, if any, that are reasonably possible of occurring. In 2018, the PUCT adopted a rule requiring investor-owned utilities operating solely inside ERCOT to make periodic filings for base rate proceedings. The rule requires ETT to file for a comprehensive base rate review no later than February 1, 2021. I&M Rate Matters (Applies to AEP and I&M) Michigan Tax Reform In October 2018, I&M made a filing with the MPSC recommending to: (a) refund Excess ADIT associated with certain depreciable property using ARAM and (b) refund Excess ADIT that is not subject to normalization requirements over ten years. In November 2019, the MPSC issued an order authorizing I&M to: (a) refund $48 million of Excess ADIT associated with certain depreciable property using ARAM and (b) refund $28 million of Excess ADIT that is not subject to normalization requirements over ten years. In January 2020, the MPSC issued an order in the 2019 Michigan Base Rate Case that changed the refund period from ten years to five years. See “2019 Michigan Base Rate Case” below. 2019 Indiana Base Rate Case In May 2019, I&M filed a request with the IURC for a $172 million annual increase. The requested increase in Indiana rates would be phased in through January 2021 and is based upon a proposed 10.5% return on common equity. The proposed annual increase includes $78 million related to a proposed annual increase in depreciation expense. The requested annual increase in depreciation expense includes $52 million related to proposed investments and $26 million related to increased depreciation rates. The request includes the continuation of all existing riders and a new Automated Metering Infrastructure (AMI) rider for proposed meter projects. In August 2019, various intervenors filed testimony that recommended annual rate increases ranging from $2 million to $33 million based upon a return on common equity ranging from 9% to 9.73%. The difference between I&M’s requested annual base rate increase and the intervenor’s recommendations are primarily due to: (a) proposed denial of return on and of certain new plant investments, (b) proposed lower depreciation rates, (c) a reduction in the requested return on common equity and (d) exclusion of I&M’s proposed re-allocation of capacity costs related to I&M’s June 2020 loss of a significant FERC wholesale contract. In addition, certain intervenors recommended disallowances that could potentially result in write-offs of $41 million related to the remaining book value of existing Indiana jurisdictional meters if I&M is approved to deploy AMI meters as initially requested and $11 million associated with certain Cook Plant study costs. In September 2019, I&M filed testimony rebutting the various intervenors’ recommendations. In October 2019, a hearing at the IURC was held. The IURC is expected to issue an order on this case in the first quarter of 2020. If any of these costs are not recoverable, it could reduce future net income and cash flows and impact financial condition. 2019 Michigan Base Rate Case In June 2019, I&M filed a request with the MPSC for a $58 million annual increase. The requested increase in Michigan rates would be phased in through June 2020 and is based upon a proposed 10.5% return on common equity. The proposed annual increase includes $19 million related to a proposed annual increase in depreciation expense. The requested annual increase in depreciation expense includes $13 million related to proposed investments and $6 million related to increased depreciation rates. The proposed annual increase also includes $10 million for annual lost revenue related to the Michigan Electric Customer Choice Program that began in 2019. In January 2020, the MPSC issued an order approving a stipulation and settlement agreement authorizing an annual base rate increase of $36 million based upon a 9.86% return on common equity effective with the first billing cycle of February 2020. The order also requires I&M to amortize and refund to customers through I&M Michigan base rates: (a) Excess ADIT that is not subject to normalization (over a period of five years starting February 2020) and (b) Excess ADIT associated with certain depreciable property using ARAM. Additionally, the order states that I&M will not be allowed to file its next base rate case before 2022. OPCo Rate Matters (Applies to AEP and OPCo) Ohio ESP Filings In 2016, OPCo filed a proposal to extend the ESP through May 2024. In April 2018, the PUCO issued an order approving the ESP extension stipulation agreement, with no significant changes. In October 2018, an intervenor filed an appeal with the Ohio Supreme Court challenging various approved riders. In January 2020, the Ohio Supreme Court affirmed the PUCO order, rejecting the filed appeal. OPCo’s Enhanced Service Reliability Rider (ESRR) authorized under the ESP is subject to annual audits. In May 2018, the PUCO staff filed comments indicating that 2016 spending under the ESRR was subject to authorized limits and that OPCo overspent those limits. In March 2019, the PUCO staff filed additional comments that OPCo overspent the authorized limit in 2017. Management believes that both 2016 and 2017 ESRR spending is not subject to an authorized limit and that a spending limit was not established until 2018, as part of the ESP extension. A hearing was held in May 2019 to address the 2016 audit. In December 2019, the PUCO issued an order finding that OPCo’s 2016 ESRR spending was not subject to an authorized limit. If it is determined OPCo did have an authorized spending limit under the ESRR in 2017, and refunds are ordered, it would reduce future net income and cash flows and impact financial condition. 2016 SEET Filing Ohio law provides for the return of significantly excessive earnings to ratepayers upon PUCO review. Significantly excessive earnings are measured by whether the earned return on common equity of the electric utility is significantly in excess of the return on common equity that was earned during the same period by publicly traded companies, including utilities, that face comparable business and financial risk. In 2016, OPCo recorded a 2016 SEET provision of $58 million based upon projected earnings data for companies in the comparable utilities risk group. In determining OPCo’s return on equity in relation to the comparable utilities risk group, management excluded the following items resolved in OPCo’s Global Settlement that was filed at the PUCO in December 2016 and subsequently approved in February 2017: (a) gain on the deferral of Retail Stability Rider costs, (b) refunds to customers related to the SEET remands and (c) refunds to customers related to fuel adjustment clause proceedings. In February 2019, the PUCO issued an order that OPCo did not have significantly excessive earnings in 2016. As a result of the order, OPCo reversed the $58 million provision in the first quarter of 2019. PSO Rate Matters (Applies to AEP and PSO) 2018 Oklahoma Base Rate Case In 2018, PSO filed a request with the OCC for an $88 million annual increase in Oklahoma retail rates based upon a 10.3% return on common equity. PSO also proposed to implement a performance-based rate plan that combines a formula rate with a set of customer-focused performance incentive measures related to reliability, public safety, customer satisfaction and economic development. The proposed annual increase included $13 million related to increased annual depreciation rates and $7 million related to increased storm expense amortization. The requested increase in annual depreciation rates included the recovery of Oklaunion Power Station through 2028 (currently being recovered in rates through 2046). Management has announced plans to retire Oklaunion Power Station by October 2020. In March 2019, the OCC issued an order approving a stipulation and settlement agreement for a $46 million annual increase, based on a 9.4% return on equity effective with the first billing cycle of April 2019. The order also included agreements between the parties that: (a) depreciation rates will remain unchanged, (b) PSO will file a new base rate request no earlier than October 2020 and no later than October 2021 and (c) PSO will refund Excess ADIT that is not subject to normalization requirements over five years instead of the ten years ordered in the Oklahoma Tax Reform case. The order did not approve the performance-based rate plan but instead provided for an expansion of the SPP Transmission Tariff that tracks previously untracked SPP costs and a new Distribution Reliability and Safety Rider that provides additional revenues capped at $5 million per year for distribution projects related to safety and reliability that are not normal distribution replacements. SWEPCo Rate Matters (Applies to AEP and SWEPCo) 2012 Texas Base Rate Case In 2012, SWEPCo filed a request with the PUCT to increase annual base rates primarily due to the completion of the Turk Plant. In 2013, the PUCT issued an order affirming the prudence of the Turk Plant but determined that the Turk Plant’s Texas jurisdictional capital cost cap established in a previous Certificate of Convenience and Necessity case also limited SWEPCo’s recovery of AFUDC in addition to limits on its recovery of cash construction costs. Upon rehearing in 2014, the PUCT reversed its initial ruling and determined that AFUDC was excluded from the Turk Plant’s Texas jurisdictional capital cost cap. As a result, SWEPCo reversed $114 million of a previously recorded regulatory disallowance in 2013. The resulting annual base rate increase was approximately $52 million. In 2017, the Texas District Court upheld the PUCT’s 2014 order and intervenors filed appeals with the Texas Third Court of Appeals. In July 2018, the Texas Third Court of Appeals reversed the PUCT’s judgment affirming the prudence of the Turk Plant and remanded the issue back to the PUCT. In January 2019, SWEPCo and the PUCT filed petitions for review with the Texas Supreme Court. In May 2019, various intervenors filed replies to the petition. In July 2019, SWEPCo filed its response to these replies. In the fourth quarter of 2019 and first quarter of 2020, SWEPCo and various intervenors filed briefs with the Texas Supreme Court. As of December 31, 2019 , the net book value of Turk Plant was $1.5 billion , before cost of removal, including materials and supplies inventory and CWIP. If certain parts of the PUCT order are overturned and if SWEPCo cannot ultimately fully recover its approximate 33% Texas jurisdictional share of the Turk Plant investment, including AFUDC, it could reduce future net income and cash flows and impact financial condition. 2016 Texas Base Rate Case In 2016, SWEPCo filed a request with the PUCT for a net increase in Texas annual revenues of $69 million based upon a 10% return on common equity. In January 2018, the PUCT issued a final order approving a net increase in Texas annual revenues of $50 million based upon a return on common equity of 9.6%, effective May 2017. The final order also included: (a) approval to recover the Texas jurisdictional share of environmental investments placed in- service, as of June 30, 2016, at various plants, including Welsh Plant, Units 1 and 3, (b) approval of recovery of, but no return on, the Texas jurisdictional share of the net book value of Welsh Plant, Unit 2, (c) approval of $2 million in additional vegetation management expenses and (d) the rejection of SWEPCo’s proposed transmission cost recovery mechanism. As a result of the final order, in 2017 SWEPCo: (a) recorded an impairment charge of $19 million, which included $7 million associated with the lack of return on Welsh Plant, Unit 2 and $12 million related to other disallowed plant investments, (b) recognized $32 million of additional revenues, for the period of May 2017 through December 2017, that was surcharged to customers in 2018 and (c) recognized an additional $7 million of expenses consisting primarily of depreciation expense and vegetation management expense, offset by the deferral of rate case expense. SWEPCo implemented new rates in February 2018 billings. The $32 million of additional 2017 revenues was collected during 2018. In March 2018, the PUCT clarified and corrected portions of the final order, without changing the overall decision or amounts of the rate change. The order has been appealed by various intervenors. If certain parts of the PUCT order are overturned, it could reduce future net income and cash flows and impact financial condition. 2018 Louisiana Formula Rate Filing In April 2018, SWEPCo filed its formula rate plan for test year 2017 with the LPSC. The filing included a net $28 million annual increase, which was effective August 2018 and included SWEPCo’s Louisiana jurisdictional share of Welsh Plant and Flint Creek Plant environmental controls. The filing also included a reduction in the federal income tax rate due to Tax Reform but did not address the return of Excess ADIT benefits to customers. In July 2018, SWEPCo made a supplemental filing to its formula rate plan with the LPSC to reduce the requested annual increase to $18 million. The difference between SWEPCo’s requested $28 million annual increase and the $18 million annual increase in the supplemental filing is primarily the result of the return of Excess ADIT benefits to customers. In October 2018, the LPSC staff issued a recommendation that SWEPCo refund $11 million of excess federal income taxes collected, as a result of Tax Reform, from January 1, 2018 through July 31, 2018. In June 2019, the LPSC staff issued its report which reaffirmed its $11 million refund recommendation. The report also contends that SWEPCo’s requested annual rate increase of $18 million, which was implemented in August 2018, is overstated by $4 million and proposes an annual rate increase of $14 million. Additionally, the report recommends SWEPCo refund the excess over-collections associated with the $4 million difference for the period of August 2018 through the implementation of new rates. In July 2019, the LPSC approved the $11 million refund. A decision by the LPSC on the remaining formula rate plan issues is expected in the first half of 2020. If any of these costs are not recoverable, it could reduce future net income and cash flows and impact financial condition. Welsh Plant - Environmental Impact Management currently estimates that the investment necessary to meet environmental regulations for Welsh Plant, Units 1 and 3 could total approximately $520 million, excluding AFUDC. As of December 31, 2019 , SWEPCo had incurred costs of $399 million, including AFUDC, related to these projects. SWEPCo has received approval to recover $340 million of its in-service investments related to environmental controls installed at Welsh Plant through base rates in its Arkansas, Louisiana and Texas jurisdictions. SWEPCo also recovers a portion of its investments related to environmental controls installed at Welsh Plant through wholesale formula rates. See “2016 Texas Base Rate Case,” “2018 Louisiana Formula Rate Filing” and “2019 Arkansas Base Rate Case” disclosures for additional information. SWEPCo will seek recovery of future costs that have not yet been approved through base rate cases. If any of the remaining costs are not recoverable, it could reduce future net income and cash flows and impact financial condition. 2019 Arkansas Base Rate Case In February 2019, SWEPCo filed a request with the APSC for a $75 million increase in Arkansas base rates based upon a proposed 10.5% return on common equity. The filing requested rate base treatment for the Stall Plant and environmental retrofits that were being recovered through riders. Eliminating these riders would result in a net annual requested base rate increase of $58 million. The proposed net annual increase included $12 million related to vegetation management to improve the reliability of its Arkansas distribution system. The filing also provided notice of SWEPCo’s proposal to have its rates regulated under the formula rate review mechanism authorized by Arkansas law, including a Formula Rate Review Rider. In October 2019, SWEPCo reduced its requested base rate increase from $75 million to $67 million. In December 2019, the APSC issued an order approving a stipulation and settlement agreement authorizing an annual base rate increase of $53 million ($24 million net of amounts currently recovered through riders) based upon a 9.45% return on common equity. The order modified the stipulation and settlement agreement and included a disallowance of $4 million for previously recorded capital incentives. The base rate increase includes $6 million for increased annual depreciation expense and became effective with the first billing cycle in January 2020. The order provides recovery for: (a) the Stall Plant, (b) environmental retrofit projects and (c) the remaining net book value, with a debt return for investors, of Welsh Unit 2. The order also states that SWEPCo’s rates will be regulated under the formula rate mechanism authorized by Arkansas law, which includes a Formula Rate Review Rider. Additionally, SWEPCo agreed to make the necessary filings with the APSC, at least 12 months in advance, to seek regulatory approval to retire the Dolet Hills Power Station no later than December 31, 2026. FERC Rate Matters FERC Transmission Complaint - AEP’s PJM Participants (Applies to AEP, AEPTCo, APCo, I&M and OPCo) In 2016, seven parties filed a complaint at the FERC that alleged the base return on common equity used by AEP’s transmission owning subsidiaries within PJM in calculating formula transmission rates under the PJM OATT is excessive and should be reduced from 10.99% to 8.32%, effective upon the date of the complaint. In March 2018, AEP’s transmission owning subsidiaries within PJM and six of the complainants filed a settlement agreement with the FERC (the seventh complainant abstained). The settlement agreement: (a) established a base ROE for AEP’s transmission owning subsidiaries within PJM of 9.85% (10.35% inclusive of the RTO incentive adder of 0.5%), effective January 1, 2018, (b) required AEP’s transmission owning subsidiaries within PJM to provide a one-time refund of $50 million, attributable from the date of the complaint through December 31, 2017, which was credited to customer bills in the second quarter of 2018 and (c) increased the cap on the equity portion of the capital structure to 55% from 50%. As part of the settlement agreement, AEP’s transmission owning subsidiaries within PJM also filed updated transmission formula rates incorporating the reduction in the corporate federal income tax rate due to Tax Reform, effective January 1, 2018 and providing for the amortization of the portion of the Excess ADIT that is not subject to normalization requirements over a ten-year period through credits to the federal income tax expense component of the revenue requirement. In May 2019, the FERC approved the settlement agreement. FERC Transmission Complaint - AEP’s SPP Participants (Applies to AEP, AEPTCo, PSO and SWEPCo) In 2017, several parties filed a complaint at the FERC that states the base return on common equity used by AEP’s transmission owning subsidiaries within SPP in calculating formula transmission rates under the SPP OATT is excessive and should be reduced from 10.7% to 8.36%, effective upon the date of the complaint through September 5, 2018. In September 2018, the same parties filed another complaint at the

Effects of Regulation

Effects of Regulation	12 Months Ended
	Dec. 31, 2019
Effects of Regulation	EFFECTS OF REGULATION The disclosures in this note apply to all Registrants unless indicated otherwise. Regulated Generating Units to be Retired (Applies to AEP, PSO and SWEPCo) In September 2018, management announced that the Oklaunion Power Station is probable of abandonment and is to be retired by October 2020. See “2018 Oklahoma Base Rate Case” for additional information. In January 2020, management announced that the Dolet Hills Power Station is probable of abandonment and is to be retired by December 2026. See “Dolet Hills Lignite Company Operations” section of Executive Overview, “2019 Arkansas Base Rate Case ” section of Note 4 , and “DHLC” section of Note 17 for additional information. The table below summarizes the plant investments and their cost of removal, currently being recovered, as well as regulatory assets for accelerated depreciation for the generating units as of December 31, 2019 . Plant Gross Investment Accumulated Depreciation Net Investment Accelerated Depreciation Regulatory Asset Materials and Supplies Cost of Removal Regulatory Liability Expected Retirement Date Remaining Recovery Period (dollars in millions) Oklaunion Power Station $ 106.7 $ 86.6 $ 20.1 $ 27.4 (a) $ 3.2 $ 5.1 2020 27 years Dolet Hills Power Station 338.9 194.2 144.7 — (b) 5.8 23.6 2026 27 years (a) In October 2018, PSO changed depreciation rates to utilize the 2020 end-of-life and defer depreciation expense to a regulatory asset for the amount in excess of the previously OCC-approved depreciation rates for Oklaunion Power Station. See “2018 Oklahoma Base Rate Case” section of Note 4 for additional information. (b) Beginning in January 2020, SWEPCo began recording a regulatory asset for accelerated depreciation. Dolet Hills Power Station and Related Fuel Operations (Applies to AEP and SWEPCo) During the second quarter of 2019, the Dolet Hills Power Station initiated a seasonal operating schedule. In January 2020, in accordance with the terms of SWEPCo’s settlement of its base rate review filed with the APSC, management announced that SWEPCo will seek regulatory approval to retire the Dolet Hills Power Station by the end of 2026. Management also continues to monitor the economic viability of the Dolet Hills Power Station and DHLC mining operations, which may result in a decision to seek permission from appropriate regulatory agencies to discontinue operations earlier than 2026. The Dolet Hills Power Station costs are recoverable by SWEPCo through base rates. SWEPCo’s share of the net investment in the Dolet Hills Power Station is $157 million , including CWIP and materials and supplies, before cost of removal. Fuel costs incurred by the Dolet Hills Power Station are recoverable by SWEPCo through active fuel clauses. Under the Lignite Mining Agreement, DHLC bills SWEPCo its proportionate share of incurred lignite extraction and associated mining-related costs as fuel is delivered. As of December 31, 2019, DHLC has unbilled fixed costs of $106 million that will be billed to SWEPCo prior to the closure of the Dolet Hills Power Station. In 2009, SWEPCo acquired interests in the Oxbow Lignite Company (Oxbow), which owns mineral rights and leases land. Under a Joint Operating Agreement pertaining to the Oxbow mineral rights and land leases, Oxbow bills SWEPCo its proportionate share of incurred costs. As of December 31, 2019, Oxbow has unbilled fixed costs of $22 million that will be billed to SWEPCo prior to the closure of the Dolet Hills Power Station. Additional operational and land-related costs are expected to be incurred by DHLC and Oxbow and billed to SWEPCo prior to the closure of the Dolet Hills Power Station and recovered through fuel clauses. If any of these costs are not recoverable, it could reduce future net income and cash flows and impact financial condition. Regulatory Assets and Liabilities Regulatory assets and liabilities are comprised of the following items: AEP December 31, Remaining Recovery Period 2019 2018 Current Regulatory Assets (in millions) Under-recovered Fuel Costs - earns a return $ 44.7 $ 101.7 1 year Under-recovered Fuel Costs - does not earn a return 48.2 48.4 1 year Total Current Regulatory Assets $ 92.9 $ 150.1 Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Unrecovered Plant $ 35.2 $ 50.3 Kentucky Deferred Purchased Power Expenses 30.2 14.5 Oklaunion Power Station Accelerated Depreciation 27.4 5.5 Other Regulatory Assets Pending Final Regulatory Approval 0.7 9.3 Total Regulatory Assets Currently Earning a Return 93.5 79.6 Regulatory Assets Currently Not Earning a Return Plant Retirement Costs - Asset Retirement Obligation Costs 30.1 35.3 Vegetation Management Program - AEP Texas (a) 29.4 — Cook Plant Study Costs 7.6 — Storm-Related Costs (b) 7.2 152.4 Asset Retirement Obligation - Louisiana 7.2 5.3 Other Regulatory Assets Pending Final Regulatory Approval 6.7 15.4 Total Regulatory Assets Currently Not Earning a Return 88.2 208.4 Total Regulatory Assets Pending Final Regulatory Approval (c) 181.7 288.0 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Unrecovered Plant 690.5 680.9 23 years Plant Retirement Costs - Asset Retirement Obligation Costs 87.4 64.3 21 years Meter Replacement Costs 65.4 74.4 8 years Environmental Control Projects 41.0 43.4 21 years Cook Plant Uprate Project 32.6 35.0 14 years Ohio Distribution Decoupling 31.4 12.3 2 years Advanced Metering System 26.5 45.3 2 years Storm-Related Costs 21.3 31.1 3 years Mitchell Plant Transfer - West Virginia 16.2 17.0 21 years Deferred Cook Plant Life Cycle Management Project Costs - Michigan 15.1 16.1 15 years Cook Plant Turbine 13.4 15.8 19 years Ohio Capacity Deferral — 57.8 Other Regulatory Assets Approved for Recovery 48.4 46.1 various Total Regulatory Assets Currently Earning a Return 1,089.2 1,139.5 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 1,309.8 1,326.6 11 years Unamortized Loss on Reacquired Debt 129.0 134.2 29 years Unrealized Loss on Forward Commitments 106.8 104.6 13 years Cook Plant Nuclear Refueling Outage Levelization 63.8 37.5 3 years Vegetation Management - West Virginia 43.6 26.6 2 years Postemployment Benefits 34.2 35.6 4 years Plant Retirement Costs - Asset Retirement Obligation Costs 28.8 21.6 23 years Medicare Subsidy 23.2 27.9 5 years Peak Demand Reduction/Energy Efficiency 18.6 31.9 7 years PJM/SPP Annual Formula Rate True Up 7.3 22.0 2 years PJM Costs and Off-system Sales Margin Sharing - Indiana — 20.1 Other Regulatory Assets Approved for Recovery 122.8 94.3 various Total Regulatory Assets Currently Not Earning a Return 1,887.9 1,882.9 Total Regulatory Assets Approved for Recovery 2,977.1 3,022.4 Total Noncurrent Regulatory Assets $ 3,158.8 $ 3,310.4 (a) Includes $26 million of deferred expenses from a stipulation and settlement agreement filed in February 2020. See “2019 Texas Base Rate Case” section of Note 4 - Rate Matters for additional information. (b) In September 2019, AEP Texas securitized $235 million of storm-related costs. As a result of the securitization, the regulatory asset balance was transferred to Securitized Assets on the balance sheets. See “Texas Storm Cost Securitization” section of Note 4 - Rate Matters for additional information. (c) In 2015, APCo recorded a $91 million reduction, before cost of removal which was $11 million and $20 million as of December 31, 2019 and 2018, respectively, to Accumulated Depreciation and Amortization related to the remaining net book value of coal plants retired in 2015, primarily related to APCo’s Virginia jurisdiction. The net book value of these plants at the retirement date was $93 million before cost of removal, including materials and supplies inventory. Based on management’s interpretation of Virginia law and more certainty regarding APCo’s triennial revenues, expenses and resulting earnings upon reaching the end of the three-year review period, APCo recorded a pretax expense of $93 million related to its previously retired coal-fired generation assets. This expense is included in Asset Impairments and Other Related Charges on the statements of income. APCo is currently in the process of retiring and replacing its Virginia jurisdictional Automated Meter Reading (AMR) meters with Advanced Metering Infrastructure (AMI) meters. As of December 31, 2019, APCo has approximately $51 million of Virginia jurisdictional AMR meters recorded in Total Property, Plant and Equipment - Net on its balance sheets. APCo intends to pursue full recovery of these assets through future depreciation rates. AEP December 31, Remaining 2019 2018 Refund Period Current Regulatory Liabilities (in millions) Over-recovered Fuel Costs - pays a return $ 77.5 $ 35.7 1 year Over-recovered Fuel Costs - does not pay a return 9.1 22.9 1 year Total Current Regulatory Liabilities $ 86.6 $ 58.6 Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits Regulatory liabilities pending final regulatory determination: Regulatory Liabilities Currently Not Paying a Return Other Regulatory Liabilities Pending Final Regulatory Determination $ 0.2 $ 0.2 Total Regulatory Liabilities Currently Not Paying a Return 0.2 0.2 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 571.8 1,025.3 (b) Excess ADIT that is Not Subject to Rate Normalization Requirements 291.0 695.0 (c) (g) Total Income Tax Related Regulatory Liabilities 862.8 1,720.3 Total Regulatory Liabilities Pending Final Regulatory Determination 863.0 1,720.5 Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs 2,876.7 2,742.8 (d) Ohio Basic Transmission Cost Rider 37.2 68.8 2 years Excess Earnings 8.3 8.9 34 years Deferred Investment Tax Credits 6.2 8.7 41 years Other Regulatory Liabilities Approved for Payment 6.1 8.9 various Total Regulatory Liabilities Currently Paying a Return 2,934.5 2,838.1 Regulatory Liabilities Currently Not Paying a Return Excess Nuclear Decommissioning Funding 1,236.0 828.5 (e) Deferred Investment Tax Credits 215.3 204.9 43 years PJM Transmission Enhancement Refund 67.3 164.2 6 years Transition and Restoration Charges - Texas 50.5 46.0 10 years Spent Nuclear Fuel 43.6 42.9 (e) Ohio Enhanced Service Reliability Plan 29.7 43.1 2 years Virginia Transmission Rate Adjustment Clause 28.1 11.3 2 years Deferred Gain on Sale of Rockport Unit 2 27.2 — 3 years Peak Demand Reduction/Energy Efficiency 23.0 17.5 2 years Unrealized Gain on Forward Commitments 17.7 45.9 5 years Other Regulatory Liabilities Approved for Payment 70.0 73.5 various Total Regulatory Liabilities Currently Not Paying a Return 1,808.4 1,477.8 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 3,303.0 2,925.7 (f) Excess ADIT that is Not Subject to Rate Normalization Requirements 890.5 864.3 17 years Income Taxes Subject to Flow Through (1,341.8 ) (1,286.1 ) 56 years Total Income Tax Related Regulatory Liabilities 2,851.7 2,503.9 Total Regulatory Liabilities Approved for Payment 7,594.6 6,819.8 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 8,457.6 $ 8,540.3 (a) This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform. The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base. See “Federal Tax Reform” section of Note 12 for additional information. (b) Includes $275 million that will be refunded using ARAM upon receiving an order in the 2019 Texas Base Rate Case. See “2019 Texas Base Rate Case” section of Note 4 - Rate Matters for additional information. (c) Includes $71 million from a stipulation and settlement agreement filed in February 2020. See “2019 Texas Base Rate Case” section of Note 4 - Rate Matters for additional information. (d) Relieved as removal costs are incurred. (e) Relieved when plant is decommissioned. (f) Refunded using ARAM. (g) 2019 and 2018 amounts include approximately $172 million related to AEP Transmission Holdco’s investment in ETT and Transource Energy. AEP Transmission Holdco expects to amortize the balance commensurate with the return of Excess ADIT to ETT and Transource Energy’s customers. AEP Texas December 31, Remaining Recovery Period Regulatory Assets: 2019 2018 (in millions) Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Not Earning a Return Vegetation Management Program (a) $ 29.4 $ — Storm-Related Costs (b) — 152.4 Other Regulatory Assets Pending Final Regulatory Approval 1.4 0.2 Total Regulatory Assets Pending Final Regulatory Approval 30.8 152.6 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Meter Replacement Costs 35.2 40.1 8 years Advanced Metering System 26.5 45.3 2 years Total Regulatory Assets Currently Earning a Return 61.7 85.4 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 172.0 176.9 11 years Unamortized Loss on Reacquired Debt 6.4 6.0 18 years Other Regulatory Assets Approved for Recovery 9.7 9.1 various Total Regulatory Assets Currently Not Earning a Return 188.1 192.0 Total Regulatory Assets Approved for Recovery 249.8 277.4 Total Noncurrent Regulatory Assets $ 280.6 $ 430.0 (a) Includes $26 million of deferred expenses from a stipulation and settlement agreement filed in February 2020. See “2019 Texas Base Rate Case” section of Note 4 - Rate Matters for additional information. (b) In September 2019, AEP Texas securitized $235 million of storm-related costs. As a result of the securitization, the regulatory asset balance was transferred to Securitized Assets on the balance sheets. See “Texas Storm Cost Securitization” section of Note 4 - Rate Matters for additional information. AEP Texas December 31, Remaining Refund Period Regulatory Liabilities: 2019 2018 (in millions) Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits Regulatory liabilities pending final regulatory determination: Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property $ 274.9 $ 277.1 (b) Excess ADIT that is Not Subject to Rate Normalization Requirements 87.1 141.4 (c) Total Regulatory Liabilities Pending Final Regulatory Determination 362.0 418.5 Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs 689.6 645.2 (d) Excess Earnings 5.8 6.3 12 years Advanced Metering Infrastructure Surcharge 4.3 8.5 1 year Total Regulatory Liabilities Currently Paying a Return 699.7 660.0 Regulatory Liabilities Currently Not Paying a Return Transition and Restoration Charges 50.5 46.0 10 years Deferred Investment Tax Credits 9.6 10.8 43 years Other Regulatory Liabilities Approved for Payment 4.8 — various Total Regulatory Liabilities Currently Not Paying a Return 64.9 56.8 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 236.5 251.8 (e) Income Taxes Subject to Flow Through (46.2 ) (42.8 ) 13 years Total Income Tax Related Regulatory Liabilities 190.3 209.0 Total Regulatory Liabilities Approved for Payment 954.9 925.8 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 1,316.9 $ 1,344.3 (a) This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform. The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base. See “Federal Tax Reform” section of Note 12 for additional information. (b) Will be refunded using ARAM upon receiving an order in the 2019 Texas Base Rate Case. See “2019 Texas Base Rate Case” section of Note 4 - Rate Matters for additional information. (c) Includes $71 million from a stipulation and settlement agreement filed in February 2020. See “2019 Texas Base Rate Case” section of Note 4 - Rate Matters for additional information. (d) Relieved as removal costs are incurred. (e) Refunded using ARAM. AEPTCo December 31, Remaining Recovery Period Regulatory Assets: 2019 2018 (in millions) Noncurrent Regulatory Assets Regulatory assets approved for recovery: Regulatory Assets Currently Not Earning a Return PJM/SPP Annual Formula Rate True Up $ 4.2 $ 12.9 2 years Total Regulatory Assets Approved for Recovery 4.2 12.9 Total Noncurrent Regulatory Assets $ 4.2 $ 12.9 AEPTCo December 31, Remaining Refund Period Regulatory Liabilities: 2019 2018 (in millions) Noncurrent Regulatory Liabilities Regulatory liabilities pending final regulatory determination: Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property $ — $ 73.9 Excess ADIT that is Not Subject to Rate Normalization Requirements — 4.5 Total Regulatory Liabilities Pending Final Regulatory Determination — 78.4 Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs 141.0 99.5 (b) Total Regulatory Liabilities Currently Paying a Return 141.0 99.5 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 535.7 453.4 (c) Excess ADIT that is Not Subject to Rate Normalization Requirements (35.4 ) (28.5 ) 9 years Income Taxes Subject to Flow Through (100.4 ) (81.5 ) 44 years Total Income Tax Related Regulatory Liabilities 399.9 343.4 Total Regulatory Liabilities Approved for Payment 540.9 442.9 Total Noncurrent Regulatory Liabilities $ 540.9 $ 521.3 (a) This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform. The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base. See “Federal Tax Reform” section of Note 12 for additional information. (b) Relieved as removal costs are incurred. (c) Refunded using ARAM. APCo December 31, Remaining Recovery Period Regulatory Assets: 2019 2018 (in millions) Current Regulatory Assets Under-recovered Fuel Costs, Virginia - earns a return $ 36.8 $ 82.4 1 year Under-recovered Fuel Costs, West Virginia - does not earn a return 5.7 17.2 1 year Total Current Regulatory Assets $ 42.5 $ 99.6 Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Materials and Supplies $ 0.5 $ 9.0 Total Regulatory Assets Currently Earning a Return 0.5 9.0 Regulatory Assets Currently Not Earning a Return Plant Retirement Costs - Asset Retirement Obligation Costs 30.1 35.3 Other Regulatory Assets Pending Final Regulatory Approval — 0.6 Total Regulatory Assets Currently Not Earning a Return 30.1 35.9 Total Regulatory Assets Pending Final Regulatory Approval (a) 30.6 44.9 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Unrecovered Plant - West Virginia 86.4 85.3 24 years Other Regulatory Assets Approved for Recovery 0.5 1.2 various Total Regulatory Assets Currently Earning a Return 86.9 86.5 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 160.8 172.2 11 years Unamortized Loss on Reacquired Debt 85.5 89.3 23 years Vegetation Management Program - West Virginia 43.6 26.6 2 years Peak Demand Reduction/Energy Efficiency 19.5 19.7 7 years Postemployment Benefits 15.9 18.0 4 years Virginia Generation Rate Adjustment Clause 5.1 10.3 2 years Other Regulatory Assets Approved for Recovery 9.3 8.3 various Total Regulatory Assets Currently Not Earning a Return 339.7 344.4 Total Regulatory Assets Approved for Recovery 426.6 430.9 Total Noncurrent Regulatory Assets $ 457.2 $ 475.8 (a) In 2015, APCo recorded a $91 million reduction, before cost of removal which was $11 million and $20 million as of December 31, 2019 and 2018, respectively, to Accumulated Depreciation and Amortization related to the remaining net book value of coal plants retired in 2015, primarily related to APCo’s Virginia jurisdiction. The net book value of these plants at the retirement date was $93 million before cost of removal, including materials and supplies inventory. Based on management’s interpretation of Virginia law and more certainty regarding APCo’s triennial revenues, expenses and resulting earnings upon reaching the end of the three-year review period, APCo recorded a pretax expense of $93 million related to its previously retired coal-fired generation assets. This expense is included in Asset Impairments and Other Related Charges on the statements of income. APCo is currently in the process of retiring and replacing its Virginia jurisdictional Automated Meter Reading (AMR) meters with Advanced Metering Infrastructure (AMI) meters. As of December 31, 2019, APCo has approximately $51 million of Virginia jurisdictional AMR meters recorded in Total Property, Plant and Equipment - Net on its balance sheets. APCo intends to pursue full recovery of these assets through future depreciation rates. APCo December 31, Remaining Refund Period Regulatory Liabilities: 2019 2018 (in millions) Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits Regulatory liabilities pending final regulatory determination: Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property $ — $ 268.2 Excess ADIT that is Not Subject to Rate Normalization Requirements — 283.7 Total Regulatory Liabilities Pending Final Regulatory Determination — 551.9 Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs 635.3 618.3 (b) Deferred Investment Tax Credits 0.5 1.0 41 years Total Regulatory Liabilities Currently Paying a Return 635.8 619.3 Regulatory Liabilities Currently Not Paying a Return Virginia Transmission Rate Adjustment Clause 28.1 11.3 2 years PJM Transmission Enhancement Refund 19.5 47.7 6 years Unrealized Gain on Forward Commitments 9.3 34.7 5 years Consumer Rate Relief - West Virginia 5.4 8.8 1 year Other Regulatory Liabilities Approved for Payment 3.3 3.9 various Total Regulatory Liabilities Currently Not Paying a Return 65.6 106.4 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 718.9 453.5 (c) Excess ADIT that is Not Subject to Rate Normalization Requirements 210.7 84.5 9 years Income Taxes Subject to Flow Through (362.3 ) (365.9 ) 23 years Total Income Tax Related Regulatory Liabilities 567.3 172.1 Total Regulatory Liabilities Approved for Payment 1,268.7 897.8 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 1,268.7 $ 1,449.7 (a) This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform. The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base. See “Federal Tax Reform” section of Note 12 for additional information. (b) Relieved as removal costs are incurred. (c) Refunded using ARAM. I&M December 31, Remaining Recovery Period Regulatory Assets: 2019 2018 (in millions) Current Regulatory Assets Under-recovered Fuel Costs - earns a return $ 3.0 $ — 1 Year Total Current Regulatory Assets $ 3.0 $ — Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Not Earning a Return Cook Plant Study Costs $ 7.6 $ — Other Regulatory Assets Pending Final Regulatory Approval 0.1 3.3 Total Regulatory Assets Pending Final Regulatory Approval 7.7 3.3 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Unrecovered Plant 214.9 232.2 9 years Cook Plant Uprate Project 32.6 35.0 14 years Deferred Cook Plant Life Cycle Management Project Costs - Michigan 15.1 16.1 15 years Cook Plant Turbine 13.4 15.8 19 years Rockport Plant Dry Sorbent Injection System - Indiana 10.2 11.5 8 years Cook Plant, Unit 2 Baffle Bolts - Indiana 5.4 5.7 19 years Other Regulatory Assets Approved for Recovery 4.8 2.4 various Total Regulatory Assets Currently Earning a Return 296.4 318.7 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 67.5 84.9 11 years Cook Plant Nuclear Refueling Outage Levelization 63.8 37.5 3 years Unamortized Loss on Reacquired Debt 17.2 18.7 29 years Postemployment Benefits 7.2 6.5 4 years PJM Costs and Off-system Sales Margin Sharing - Indiana — 20.1 Other Regulatory Assets Approved for Recovery 22.3 22.8 various Total Regulatory Assets Currently Not Earning a Return 178.0 190.5 Total Regulatory Assets Approved for Recovery 474.4 509.2 Total Noncurrent Regulatory Assets $ 482.1 $ 512.5 I&M December 31, Remaining Refund Period Regulatory Liabilities: 2019 2018 (in millions) Current Regulatory Liabilities Over-recovered Fuel Costs, Michigan - pays a return $ — $ 4.5 Over-recovered Fuel Costs, Indiana - does not pay a return 6.1 22.9 1 year Total Current Regulatory Liabilities $ 6.1 $ 27.4 Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits Regulatory liabilities pending final regulatory determination: Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property $ — $ 125.0 Excess ADIT that is Not Subject to Rate Normalization Requirements — 40.6 Total Regulatory Liabilities Pending Final Regulatory Determination — 165.6 Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs 166.7 182.5 (b) Other Regulatory Liabilities Approved for Payment 0.3 — various Total Regulatory Liabilities Currently Paying a Return 167.0 182.5 Regulatory Liabilities Currently Not Paying a Return Excess Nuclear Decommissioning Funding 1,236.0 828.5 (c) Spent Nuclear Fuel 43.6 42.9 (c) Deferred Investment Tax Credits 25.8 29.4 20 years PJM Costs and Off-system Sales Margin Sharing - Indiana 17.0 — 2 years PJM Transmission Enhancement Refund 11.8 29.1 6 years Deferred Gain on Sale of Rockport Unit 2 10.9 — 3 years Other Regulatory Liabilities Approved for Payment 24.9 24.0 various Total Regulatory Liabilities Currently Not Paying a Return 1,370.0 953.9 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 470.9 362.0 (d) Excess ADIT that is Not Subject to Rate Normalization Requirements 184.5 192.6 5 years Income Taxes Subject to Flow Through (301.0 ) (282.1 ) 19 years Total Income Tax Related Regulatory Liabilities 354.4 272.5 Total Regulatory Liabilities Approved for Payment 1,891.4 1,408.9 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 1,891.4 $ 1,574.5 (a) This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform. The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base. See “Federal Tax Reform” section of Note 12 for additional information. (b) Relieved as removal costs are incurred. (c) Relieved when plant is decommissioned. (d) Refunded using ARAM. OPCo December 31, Remaining Recovery Period Regulatory Assets: 2019 2018 (in millions) Current Regulatory Assets Under-recovered Fuel Costs - earns a return $ — $ 0.4 Total Current Regulatory Assets $ — $ 0.4 Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Not Earning a Return Other Regulatory Assets Pending Final Regulatory Approval $ 0.1 $ 1.0 Total Regulatory Assets Pending Final Regulatory Approval 0.1 1.0 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Ohio Distribution Decoupling 31.4 12.3 2 years Ohio Capacity Deferral — 57.8 Other Regulatory Assets Approved for Recovery — 0.9 Total Regulatory Assets Currently Earning a Return 31.4 71.0 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 167.3 181.5 11 years Unrealized Loss on Forward Commitments 103.6 100.2 13 years Smart Grid Costs 13.7 8.1 2 years Distribution Investment Rider 10.9 — 2 years Postemployment Benefits 7.6 7.9 4 years Unamortized Loss on Reacquired Debt 5.3 6.5 19 years Other Regulatory Assets Approved for Recovery 11.9 11.3 various Total Regulatory Assets Currently Not Earning a Return 320.3 315.5 Total Regulatory Assets Approved for Recovery 351.7 386.5 Total Noncurrent Regulatory Assets $ 351.8 $ 387.5 OPCo December 31, Remaining Refund Period 2019 2018 Regulatory Liabilities: (in millions) Current Regulatory Liabilities Over-recovered Fuel Costs - does not pay a return $ 2.8 $ — 1 year Total Current Regulatory Liabilities $ 2.8 $ — Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits Regulatory liabilities pending final regulatory determination: Regulatory Liabilities Currently Not Paying a Return Other Regulatory Liabilities Pending Final Regulatory Determination $ 0.2 $ 0.2 Total Regulatory Liabilities Pending Final Regulatory Determination 0.2 0.2 Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs 446.3 436.6 (b) Ohio Basic Transmission Cost Rider 37.2 68.8 2 years Other Regulatory Liabilities Approved for Payment 1.3 0.4 various Total Regulatory Liabilities Currently Paying a Return 484.8 505.8 Regulatory Liabilities Currently Not Paying a Return Ohio Enhanced Service Reliability Plan 29.7 43.1 2 years PJM Transmission Enhancement Refund 29.4 71.3 6 years Peak Demand Reduction/Energy Efficiency 19.7 14.9 2 years Distribution Investment Rider — 7.8 Other Regulatory Liabilities Approved for Payment 2.9 11.3 various Total Regulatory Liabilities Currently Not Paying a Return 81.7 148.4 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 341.6 350.5 (c) Excess ADIT that is Not Subject to Rate Normalization Requirements 252.3 279.1 9 years Income Taxes Subject to Flow Through (69.7 ) (62.8 ) 28 years Total Income Tax Related Regulatory Liabilities 524.2 566.8 Total Regulatory Liabilities Approved for Payment 1,090.7 1,221.0 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 1,090.9 $ 1,221.2 (a) This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform. The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base. See “Federal Tax Reform” section of Note 12 for additional information. (b) Relieved as removal costs are incurred. (c) Refunded using ARAM. PSO December 31, Remaining Recovery Period 2019 2018 Regulatory Assets: (in millions) Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Earning a Return Oklaunion Power Station Accelerated Depreciation $ 27.4 $ 5.5 Total Regulatory Assets Currently Earning a Return 27.4 5.5 Regulatory Assets Currently Not Earning a Return Storm-Related Costs 7.2 — Other Regulatory Assets Pending Final Regulatory Approval — 0.5 Total Regulatory Assets Currently Not Earning a Return 7.2 0.5 Total Regulatory Assets Pending Final Regulatory Approval 34.6 6.0 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Unrecovered Plant 167.0 153.4 21 years Meter Replacement Costs 30.2 34.3 8 years Environmental Control Projects 27.8 29.2 21 years Storm-Related Costs 21.3 31.1 3 years Red Rock Generating Facility 8.4 8.6 37 years Other Regulatory Assets Approved for Recovery 0.6 0.5 various Total Regulatory Assets Currently Earning a Return 255.3 257.1 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 73.4 84.3 11 years Unamortized Loss on Reacquired Debt 6.5 4.3 15 years Peak Demand Reduction/Energy Efficiency — 6.3 Other Regulatory Assets Approved for Recovery 5.4 11.0 various Total Regulatory Assets Currently Not Earning a Return 85.3 105.9 Total Regulatory Assets Approved for Recovery 340.6 363.0 Total Noncurrent Regulatory Assets $ 375.2 $ 369.0 PSO December 31, Remaining Refund Period 2019 2018 Regulatory Liabilities: (in mil

Commitments, Guarantees and Con

Commitments, Guarantees and Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments, Guarantees and Contingencies	COMMITMENTS, GUARANTEES AND CONTINGENCIES The disclosures in this note apply to all Registrants unless indicated otherwise. The Registrants are subject to certain claims and legal actions arising in the ordinary course of business. In addition, the Registrants business activities are subject to extensive governmental regulation related to public health and the environment. The ultimate outcome of such pending or potential litigation against the Registrants cannot be predicted. Management accrues contingent liabilities only when management concludes that it is both probable that a liability has been incurred at the date of the financial statements and the amount of loss can be reasonably estimated. When management determines that it is not probable, but rather reasonably possible that a liability has been incurred at the date of the financial statements, management discloses such contingencies and the possible loss or range of loss if such estimate can be made. Any estimated range is based on currently available information and involves elements of judgment and significant uncertainties. Any estimated range of possible loss may not represent the maximum possible loss exposure. Circumstances change over time and actual results may vary significantly from estimates. For current proceedings not specifically discussed below, management does not anticipate that the liabilities, if any, arising from such proceedings would have a material effect on the financial statements. COMMITMENTS (Applies to all Registrants except AEP Texas and AEPTCo) The AEP System has substantial commitments for fuel, energy and capacity contracts as part of the normal course of business. Certain contracts contain penalty provisions for early termination. In accordance with the accounting guidance for “Commitments”, the following tables summarize the Registrants’ actual contractual commitments as of December 31, 2019 : Contractual Commitments - AEP Less Than 1 Year 2-3 Years 4-5 Years After 5 Years Total (in millions) Fuel Purchase Contracts (a) $ 1,047.0 $ 1,105.0 $ 234.4 $ 111.4 $ 2,497.8 Energy and Capacity Purchase Contracts 227.8 353.2 273.5 1,080.0 1,934.5 Total $ 1,274.8 $ 1,458.2 $ 507.9 $ 1,191.4 $ 4,432.3 Contractual Commitments - APCo Less Than 1 Year 2-3 Years 4-5 Years After 5 Years Total (in millions) Fuel Purchase Contracts (a) $ 415.3 $ 369.2 $ 4.6 $ 0.3 $ 789.4 Energy and Capacity Purchase Contracts 35.4 72.1 73.7 275.5 456.7 Total $ 450.7 $ 441.3 $ 78.3 $ 275.8 $ 1,246.1 Contractual Commitments - I&M Less Than 1 Year 2-3 Years 4-5 Years After 5 Years Total (in millions) Fuel Purchase Contracts (a) $ 299.8 $ 340.7 $ 211.6 $ 67.2 $ 919.3 Energy and Capacity Purchase Contracts 151.0 340.5 60.4 289.2 841.1 Total $ 450.8 $ 681.2 $ 272.0 $ 356.4 $ 1,760.4 Contractual Commitments - OPCo Less Than 1 Year 2-3 Years 4-5 Years After 5 Years Total (in millions) Energy and Capacity Purchase Contracts $ 29.0 $ 58.6 $ 58.8 $ 302.5 $ 448.9 Contractual Commitments - PSO Less Than 1 Year 2-3 Years 4-5 Years After 5 Years Total (in millions) Fuel Purchase Contracts (a) $ 52.3 $ 42.8 $ — $ — $ 95.1 Energy and Capacity Purchase Contracts 93.0 132.3 65.2 193.3 483.8 Total $ 145.3 $ 175.1 $ 65.2 $ 193.3 $ 578.9 Contractual Commitments - SWEPCo Less Than 1 Year 2-3 Years 4-5 Years After 5 Years Total (in millions) Fuel Purchase Contracts (a) $ 130.4 $ 147.4 $ 4.5 $ — $ 282.3 Energy and Capacity Purchase Contracts 14.0 12.5 8.4 8.4 43.3 Total $ 144.4 $ 159.9 $ 12.9 $ 8.4 $ 325.6 (a) Represents contractual commitments to purchase coal, natural gas, uranium and other consumables as fuel for electric generation along with related transportation of the fuel. GUARANTEES Liabilities for guarantees are recorded in accordance with the accounting guidance for “Guarantees.” There is no collateral held in relation to any guarantees. In the event any guarantee is drawn, there is no recourse to third-parties unless specified below. Letters of Credit (Applies to AEP, AEP Texas and OPCo) Standby letters of credit are entered into with third-parties. These letters of credit are issued in the ordinary course of business and cover items such as natural gas and electricity risk management contracts, construction contracts, insurance programs, security deposits and debt service reserves. AEP has a $4 billion revolving credit facility due in June 2022, under which up to $1.2 billion may be issued as letters of credit on behalf of subsidiaries. As of December 31, 2019 , no letters of credit were issued under the revolving credit facility. An uncommitted facility gives the issuer of the facility the right to accept or decline each request made under the facility. AEP issues letters of credit on behalf of subsidiaries under six uncommitted facilities totaling $405 million . The Registrants’ maximum future payments for letters of credit issued under the uncommitted facilities as of December 31, 2019 were as follows: Company Amount Maturity (in millions) AEP $ 206.8 January 2020 to December 2020 AEP Texas 2.2 July 2020 OPCo 1.6 April 2020 to September 2020 Guarantees of Equity Method Investees (Applies to AEP) In April 2019, AEP acquired Sempra Renewables LLC. See “Acquisitions” section of Note 7 for additional information. Indemnifications and Other Guarantees Contracts The Registrants enter into certain types of contracts which require indemnifications. Typically these contracts include, but are not limited to, sale agreements, lease agreements, purchase agreements and financing agreements. Generally, these agreements may include, but are not limited to, indemnifications around certain tax, contractual and environmental matters. With respect to sale agreements, exposure generally does not exceed the sale price. As of December 31, 2019 , there were no material liabilities recorded for any indemnifications. AEPSC conducts power purchase and sale activity on behalf of APCo, I&M, KPCo and WPCo, who are jointly and severally liable for activity conducted on their behalf. AEPSC also conducts power purchase and sale activity on behalf of PSO and SWEPCo, who are jointly and severally liable for activity conducted on their behalf. Lease Obligations Certain Registrants lease equipment under master lease agreements. See “Master Lease Agreements” and “AEPRO Boat and Barge Leases” sections of Note 13 for additional information. ENVIRONMENTAL CONTINGENCIES (Applies to All Registrants except AEPTCo) The Comprehensive Environmental Response Compensation and Liability Act (Superfund) and State Remediation By-products from the generation of electricity include materials such as ash, slag, sludge, low-level radioactive waste and SNF. Coal combustion by-products, which constitute the overwhelming percentage of these materials, are typically treated and deposited in captive disposal facilities or are beneficially utilized. In addition, the generation plants and transmission and distribution facilities have used asbestos, polychlorinated biphenyls and other hazardous and non-hazardous materials. The Registrants currently incur costs to dispose of these substances safely. Superfund addresses clean-up of hazardous substances that are released to the environment. The Federal EPA administers the clean-up programs. Several states enacted similar laws. As of December 31, 2019 , APCo, OPCo and SWEPCo are named as a Potentially Responsible Party (PRP) for one, three, and one sites, respectively, by the Federal EPA for which alleged liability is unresolved. There are 11 additional sites for which APCo, I&M, KPCo, OPCo and SWEPCo received information requests which could lead to PRP designation. I&M has also been named potentially liable at three sites under state law. In those instances where a PRP or defendant has been named, disposal or recycling activities were in accordance with the then-applicable laws and regulations. Superfund does not recognize compliance as a defense, but imposes strict liability on parties who fall within its broad statutory categories. Liability has been resolved for a number of sites with no significant effect on net income. Management evaluates the potential liability for each Superfund site separately, but several general statements can be made about potential future liability. Allegations that materials were disposed at a particular site are often unsubstantiated and the quantity of materials deposited at a site can be small and often non-hazardous. Although Superfund liability has been interpreted by the courts as joint and several, typically many parties are named as PRPs for each site and several of the parties are financially sound enterprises. As of December 31, 2019 , management’s estimates do not anticipate material clean-up costs for identified Superfund sites. NUCLEAR CONTINGENCIES (APPLIES TO AEP AND I&M) I&M owns and operates the two-unit 2,288 MW Cook Plant under licenses granted by the NRC. I&M has a significant future financial commitment to dispose of SNF and to safely decommission and decontaminate the plant. The licenses to operate the two nuclear units at the Cook Plant expire in 2034 and 2037. The operation of a nuclear facility also involves special risks, potential liabilities and specific regulatory and safety requirements. By agreement, I&M is partially liable, together with all other electric utility companies that own nuclear generation units, for a nuclear power plant incident at any nuclear plant in the U.S. Should a nuclear incident occur at any nuclear power plant in the U.S., the resultant liability could be substantial. Decommissioning and Low-Level Waste Accumulation Disposal The costs to decommission a nuclear plant are affected by NRC regulations and the SNF disposal program. Decommissioning costs are accrued over the service life of Cook Plant. The most recent decommissioning cost study was performed in 2018. According to that study, the estimated cost of decommissioning and disposal of low-level radioactive waste was $2 billion in 2018 non-discounted dollars, with additional ongoing costs of $6 million per year for post decommissioning storage of SNF and an eventual cost of $37 million for the subsequent decommissioning of the SNF storage facility, also in 2018 non-discounted dollars. I&M recovers estimated decommissioning costs for the Cook Plant in its rates. The amounts recovered in rates were $7 million , $8 million and $9 million for the years ended December 31, 2019 , 2018 and 2017 , respectively. Decommissioning costs recovered from customers are deposited in external trusts. As of December 31, 2019 and 2018 , the total decommissioning trust fund balances were $2.7 billion and $2.2 billion , respectively. Trust fund earnings increase the fund assets and decrease the amount remaining to be recovered from customers. The decommissioning costs (including unrealized gains and losses, interest and trust funds expenses) increase or decrease the recorded liability. I&M continues to work with regulators and customers to recover the remaining estimated costs of decommissioning the Cook Plant. However, future net income and cash flows would be reduced and financial condition could be impacted if the cost of SNF disposal and decommissioning continues to increase and cannot be recovered. Spent Nuclear Fuel Disposal The federal government is responsible for permanent SNF disposal and assesses fees to nuclear plant owners for SNF disposal. A fee of one-mill per KWh for fuel consumed after April 6, 1983 at the Cook Plant was collected from customers and remitted to the DOE through May 14, 2014. In May 2014, pursuant to court order from the U.S Court of Appeals for the District of Columbia Circuit, the DOE adjusted the fee to $0 . As of December 31, 2019 and 2018 , fees and related interest of $280 million and $274 million , respectively, for fuel consumed prior to April 7, 1983 were recorded as Long-term Debt and funds collected from customers along with related earnings totaling $323 million and $317 million , respectively, to pay the fee were recorded as part of Spent Nuclear Fuel and Decommissioning Trusts on the balance sheets. I&M has not paid the government the pre-April 1983 fees due to continued delays and uncertainties related to the federal disposal program. In 2011, I&M signed a settlement agreement with the federal government which permits I&M to make annual filings to recover certain SNF storage costs incurred as a result of the government’s delay in accepting SNF for permanent storage. Under the settlement agreement, I&M received $8 million , $11 million and $22 million in 2019 , 2018 and 2017 , respectively, to recover costs and will be eligible to receive additional payment of annual claims for allowed costs that are incurred through December 31, 2019. The proceeds reduced costs for dry cask storage. As of December 31, 2019 and 2018 , I&M deferred $24 million and $8 million , respectively, in Prepayments and Other Current Assets and $1 million and $23 million , respectively, in Deferred Charges and Other Noncurrent Assets on the balance sheets for dry cask storage and related operation and maintenance costs for recovery under this agreement. See “Fair Value Measurements of Trust Assets for Decommissioning and SNF Disposal” section of Note 11 for additional information. Nuclear Insurance I&M carries nuclear property insurance of $2.7 billion to cover an incident at Cook Plant including coverage for decontamination and stabilization, as well as premature decommissioning caused by an extraordinary incident. Insurance coverage for a nonnuclear property incident at Cook Plant is $1 billion . Additional insurance provides coverage for a weekly indemnity payment resulting from an insured accidental outage. I&M utilizes industry mutual insurers for the placement of this insurance coverage. Coverage from these industry mutual insurance programs require a contingent financial obligation of up to $47 million for I&M, which is assessable if the insurer’s financial resources would be inadequate to pay for industry losses. The Price-Anderson Act, extended through December 31, 2025, establishes insurance protection for public nuclear liability arising from a nuclear incident of $13.9 billion and applies to any incident at a licensed reactor in the U.S. Commercially available insurance, which must be carried for each licensed reactor, provides $450 million of coverage. In the event of a nuclear incident at any nuclear plant in the U.S., the remainder of the liability would be provided by a deferred premium assessment of $275 million per nuclear incident on Cook Plant’s reactors payable in annual installments of $41 million . The number of incidents for which payments could be required is not limited. In the event of an incident of a catastrophic nature, I&M is covered for public nuclear liability for the first $450 million through commercially available insurance. The next level of liability coverage of up to $13.5 billion would be covered by claim premium assessments made under the Price-Anderson Act. In the event nuclear losses or liabilities are underinsured or exceed accumulated funds, I&M would seek recovery of those amounts from customers through a rate increase. If recovery from customers is not possible, it could reduce future net income and cash flows and impact financial condition. OPERATIONAL CONTINGENCIES Insurance and Potential Losses The Registrants maintain insurance coverage normal and customary for electric utilities, subject to various deductibles. The Registrants also maintain property and casualty insurance that may cover certain physical damage or third-party injuries caused by cyber security incidents. Insurance coverage includes all risks of physical loss or damage to nonnuclear assets, subject to insurance policy conditions and exclusions. Covered property generally includes power plants, substations, facilities and inventories. Excluded property generally includes transmission and distribution lines, poles and towers. The insurance programs also generally provide coverage against loss arising from certain claims made by third-parties and are in excess of retentions absorbed by the Registrants. Coverage is generally provided by a combination of the protected cell of EIS and/or various industry mutual and/or commercial insurance carriers. See “Nuclear Contingencies” section above for additional information. Some potential losses or liabilities may not be insurable or the amount of insurance carried may not be sufficient to meet potential losses and liabilities, including, but not limited to, liabilities relating to a cyber security incident or damage to the Cook Plant and costs of replacement power in the event of an incident at the Cook Plant. Future losses or liabilities, if they occur, which are not completely insured, unless recovered from customers, could reduce future net income and cash flows and impact financial condition. Rockport Plant Litigation (Applies to AEP and I&M) In 2013, the Wilmington Trust Company filed a complaint in the U.S. District Court for the Southern District of New York against AEGCo and I&M alleging that it would be unlawfully burdened by the terms of the modified NSR consent decree after the Rockport Plant, Unit 2 lease expiration in December 2022. The terms of the consent decree allow the installation of environmental emission control equipment, repowering, refueling or retirement of the unit. The plaintiffs seek a judgment declaring that the defendants breached the lease, must satisfy obligations related to installation of emission control equipment and indemnify the plaintiffs. The New York court granted a motion to transfer this case to the U.S. District Court for the Southern District of Ohio. AEGCo and I&M sought and were granted dismissal by the U.S. District Court for the Southern District of Ohio of certain of the plaintiffs’ claims, including claims for compensatory damages, breach of contract, breach of the implied covenant of good faith and fair dealing and indemnification of costs. Plaintiffs voluntarily dismissed the surviving claims that AEGCo and I&M failed to exercise prudent utility practices with prejudice, and the court issued a final judgment. The plaintiffs subsequently filed an appeal in the U.S. Court of Appeals for the Sixth Circuit. In 2017, the U.S. Court of Appeals for the Sixth Circuit issued an opinion and judgment affirming the district court’s dismissal of the owners’ breach of good faith and fair dealing claim as duplicative of the breach of contract claims, reversing the district court’s dismissal of the breach of contract claims and remanding the case for further proceedings. Thereafter, AEP filed a motion with the U.S. District Court for the Southern District of Ohio in the original NSR litigation, seeking to modify the consent decree. The district court granted the owners’ unopposed motion to stay the lease litigation to afford time for resolution of AEP’s motion to modify the consent decree. The consent decree was modified based on an agreement among the parties in July 2019. As part of the modification to the consent decree, I&M agreed to provide an additional $7.5 million to citizens’ groups and the states for environmental mitigation projects. As joint owners in the Rockport Plant, the $7.5 million payment was shared between AEGCo and I&M based on the joint ownership agreement. The district court entered a stay that expired in February 2020. Settlement negotiations are continuing, and the parties filed a joint proposed case schedule in February 2020. See “Modification of the New Source Review Litigation Consent Decree” section of Management’s Discussion and Analysis of Financial Condition and Results of Operations for additional information. Management will continue to defend against the claims. Given that the district court dismissed plaintiffs’ claims seeking compensatory relief as premature, and that plaintiffs have yet to present a methodology for determining or any analysis supporting any alleged damages, management cannot determine a range of potential losses that is reasonably possible of occurring. Patent Infringement Complaint In July 2019, Midwest Energy Emissions Corporation and MES Inc. (collectively, the plaintiffs) filed a patent infringement complaint against various parties, including AEP Texas, AGR, Cardinal Operating Company and SWEPCo (collectively, the AEP Defendants). The complaint alleges that the AEP Defendants infringed two patents owned by the plaintiffs by using specific processes for mercury control at certain coal-fired generating stations. The complaint seeks injunctive relief and damages. Management will continue to defend against the claims. Management is unable to determine a range of potential losses that is reasonably possible of occurring. Claims Challenging Transition of American Electric Power System Retirement Plan to Cash Balance Formula The American Electric Power System Retirement Plan (the Plan) has received a letter written on behalf of four participants (the Claimants) making a claim for additional plan benefits and purporting to advance such claims on behalf of a class. When the Plan’s benefit formula was changed in the year 2000, AEP provided a special provision for employees hired before January 1, 2001, allowing them to continue benefit accruals under the then benefit formula for a full 10 years alongside of the new cash balance benefit formula then being implemented. Employees who were hired on or after January 1, 2001 accrued benefits only under the new cash balance benefit formula. The Claimants have asserted claims that (a) the Plan violates the requirements under the Employee Retirement Income Security Act (ERISA) intended to preclude back-loading the accrual of benefits to the end of a participant’s career; (b) the Plan violates the age discrimination prohibitions of ERISA and the Age Discrimination in Employment Act (ADEA); and (c) the company failed to provide required notice regarding the changes to the Plan. AEP has responded to the Claimants providing a reasoned explanation for why each of their claims have been denied, and offering an opportunity to appeal those determinations. Management will continue to defend against the claims. Management is unable to determine a range of potential losses that are reasonably possible of occurring.

Dispositions, Assets and Liabil

Dispositions, Assets and Liabilities Held for Sale and Impairments	12 Months Ended
	Dec. 31, 2019
Impairments, Disposition and Assets and Liabilities Held for Sale	DISPOSITIONS AND IMPAIRMENTS The disclosures in this note apply to AEP unless indicated otherwise. ACQUISITIONS 2019 Sempra Renewables LLC (Generation & Marketing Segment) In April 2019, AEP acquired Sempra Renewables LLC and its ownership interests in 724 MWs of wind generation and battery assets valued at approximately $1.1 billion . This acquisition is part of AEP’s strategy to grow its renewable generation portfolio and to diversify generation resources. AEP paid $580 million in cash and acquired a 50% ownership interest in five non-consolidated joint ventures with net assets valued at $404 million as of the acquisition date (which includes $364 million of existing debt obligations). Additionally, the transaction included the acquisition of two tax equity partnerships and the associated recognition of noncontrolling tax equity interest of $135 million . The purchase price was allocated as follows: Purchase Price Allocation of Sempra Renewables LLC at Acquisition Date - April 22nd, 2019 Assets: Liabilities and Equity: Net Purchase Price (in millions) Current Assets $ 8.8 Current Liabilities $ 12.9 Property, Plant and Equipment 238.1 Asset Retirement Obligations 5.7 Investment in Joint Ventures 404.0 Total Liabilities 18.6 Other Noncurrent Assets 82.9 Noncontrolling Interest 134.8 Total Assets $ 733.8 Liabilities and Noncontrolling Interest $ 153.4 $ 580.4 Management allocated the purchase price based upon the relative fair value of the assets acquired and noncontrolling interests assumed. The fair value of the primary assets acquired and the noncontrolling interests assumed was determined using a discounted cash flow method under the income approach. The key input assumptions utilized in the determination of the fair value of these assets were the pricing and terms of the existing PPAs, forecasted market power prices, expected wind farm net capacity and discount rates reflecting risk inherent in the future cash flows and future power prices. Estimating forecasted market power prices involved determining the cost of constructing and operating a new wind plant over an assumed life in the same geographic region as of the acquisition date using third-party market participant assumptions. The expected wind farm net capacity was developed by evaluating each wind farm’s historical and expected generation against historical generation of comparable wind farms in the same locations. Discount rates were evaluated by considering the cost of capital of comparable businesses. Additional key input assumptions for the fair value of the noncontrolling interests include the terms of the limited liability company agreements that dictate the sharing of the tax attributes and cash flows associated with the tax equity partnerships. Under the accounting rules for acquisitions, AEP has one year to finalize the purchase price allocation, including working capital adjustments and other closing adjustments. Upon closing of the purchase, Sempra Renewables LLC was legally renamed AEP Wind Holdings LLC. AEP Wind Holdings LLC develops, owns and operates, or holds interests in, wind generation facilities in the United States. The operating wind generation portfolio includes seven wind farms. Five wind farms are jointly-owned with BP Wind Energy, and two wind farms are consolidated by AEP and are tax equity partnerships with nonaffiliated noncontrolling interests. All seven wind farms have long-term PPAs for 100% of their energy production. One of the joint venture wind farms has PPAs with I&M and OPCo for a portion of its energy production which totaled $9 million and $17 million , respectively, for the year ended December 31, 2019 . Another joint venture wind farm has a PPA with SWEPCo for a portion of its energy production which totaled $10 million of purchased electricity for the year ended December 31, 2019 . The PPAs with I&M, OPCo and SWEPCo were executed prior to the acquisition of the wind farms and will be accounted for in accordance with the accounting guidance for “Related Parties.” Parent has issued guarantees over the performance of the joint ventures. If a joint venture were to default on payments or performance, Parent would be required to make payments on behalf of the joint venture. As of December 31, 2019, the maximum potential amount of future payments associated with these guarantees was $175 million , with the last guarantee expiring in December 2037. The liability recorded associated with these guarantees was $34 million as of December 31, 2019 . The acquired business contributed revenues and net income to AEP that were not material for the period April 22, 2019 to December 31, 2019 . The pro-forma revenue and net income related to the acquisition of Sempra Renewables LLC were not material for the year ended December 31, 2019 . See Note 17 - Variable Interest Entities and Equity Method Investments for additional information related to the purchased wind farms. Santa Rita East (Generation & Marketing Segment) In July 2019, AEP acquired a 75% interest, or 227 MWs, in Santa Rita East for approximately $356 million . In accordance with the accounting guidance for “Business Combinations,” management determined that the acquisition of Santa Rita East represents an asset acquisition. Additionally, and in accordance with the accounting guidance for “Consolidation,” management concluded that Santa Rita East is a VIE. As a result, to account for the initial consolidation of Santa Rita East, management applied the acquisition method by allocating the purchase price based on the relative fair value of the assets acquired and noncontrolling interest assumed. The fair value of the primary assets acquired and the noncontrolling interest assumed was determined using the market approach. The key input assumptions were the transaction price paid for AEP’s interest in Santa Rita East and recent third-party market transactions for similar wind farms. See “Santa Rita East” section of Note 17 for additional information. DISPOSITIONS 2017 Zimmer Plant (Generation & Marketing Segment) In February 2017, AEP signed an agreement to sell its 25.4% ownership share of Zimmer Plant to a nonaffiliated party. The transaction closed in the second quarter of 2017 and did not have a material impact on net income, cash flows or financial condition. The Income before Income Tax Expense and Equity Earnings of Zimmer Plant was immaterial for the years ended December 31, 2017 and 2016. Gavin, Waterford, Darby and Lawrenceburg Plants (Generation & Marketing Segment) In September 2016, AEP signed a Purchase and Sale Agreement to sell AGR’s Gavin, Waterford and Darby Plants as well as AEGCo’s Lawrenceburg Plant totaling 5,329 MWs of competitive generation assets to a nonaffiliated party. The sale closed in January 2017 for $2.2 billion , which was recorded in Investing Activities on the statements of cash flows. The net proceeds from the transaction were $1.2 billion in cash after taxes, repayment of debt associated with these assets including a make whole payment related to the debt, payment of a coal contract associated with one of the plants and transaction fees. The sale resulted in a pretax gain of $226 million that was recorded in Gain on Sale of Merchant Generation Assets on AEP’s statements of income for the year ended December 31, 2017. IMPAIRMENTS 2019 2019 Texas Base Rate Case (Transmission and Distribution Segment) (Applies to AEP and AEP Texas) In December 2019, AEP Texas recorded a pretax impairment of $33 million in Asset Impairments and Other Related Charges on the statements of income due to regulatory disallowances in the 2019 Texas Base Rate Case. See “2019 Texas Base Rate Case” section of Note 4 for additional information. Virginia Jurisdictional Book Value of Retired Coal-Fired Plants (Vertically Integrated Utilities Segment) (Applies to AEP and APCo) In December 2019, based on management’s interpretation of Virginia law and more certainty regarding APCo’s triennial revenues, expenses and resulting earnings upon reaching the end of the three-year review period, APCo recorded a pretax expense of $93 million related to its previously retired coal-fired generation. This expense is recorded in Asset Impairments and Other Related Charges on the statements of income. See “Virginia Legislation Affecting Earnings Reviews” section of Note 4 for additional information. Merchant Generating Assets (Generation & Marketing Segment) Due to a significant increase in the asset retirement costs recorded in December 2019 for the Ash Pond Complex at Conesville Plant, AEP performed an impairment analysis on Conesville Plant in accordance with accounting guidance for impairments of long-lived assets. AEP performed step one and step two of the impairment analysis using a cash flow model for the estimated useful life of Conesville Plant based upon energy and capacity price curves, which were developed internally with both observable Level 2 third-party quotations and unobservable Level 3 inputs, as well as management’s forecasts of operating expenses. The step two analysis resulted in a fair value determination for Conesville Plant of $0 and AEP recorded a $31 million pretax impairment, equal to the net book value of the plant, in Asset Impairments and Other Related Charges on AEP’s statements of income in the fourth quarter of 2019. 2018 Other Assets (Corporate and Other) (Vertically Integrated Utilities Segment) (Applies to AEP and APCo) In the first quarter of 2018, AEP was notified by an equity investee that it had ceased operations. AEP recorded a pretax impairment of $21 million in Asset Impairments and Other Related Charges on the statements of income related to the equity investment and related assets. The impairment also had an immaterial impact to APCo. Merchant Generating Assets (Generation & Marketing Segment) A project to reconstruct a defective dam structure at Racine began in the first quarter of 2017 and reconstruction activities continued throughout 2018. An initial impairment recorded related to Racine is discussed in the “2017” section below. As of September 30, 2018, the Racine reconstruction project had accumulated new capital expenditures of $35 million . Due to a significant increase in estimated costs to complete the reconstruction project, in the third quarter of 2018, an impairment analysis was performed. AEP performed step one of the impairment analysis using undiscounted cash flows for the estimated useful life of Racine based upon energy and capacity price curves, which were developed internally with observable Level 2 third-party quotations and unobservable Level 3 inputs, as well as management’s forecasts of operating expenses and capital expenditures. AEP performed step two of the impairment analysis on Racine using a ten-year discounted cash flow model based upon similar forecasted information used in the step one test. The step two analysis resulted in a determination that the fair value of Racine in its condition as of September 30, 2018 was $0 . As a result, AEP recorded a pretax impairment of $35 million in Other Operation on the statements of income in the third quarter of 2018. In October 2018, AEP received authorization from the FERC to restart generation at Racine and generation resumed in November 2018. Reconstruction activities at Racine are currently estimated to be completed in the first half of 2020. AEP expects to incur additional capital expenditures to complete the reconstruction project, at which point the fair value of Racine, as fully operational, is expected to approximate the book value once complete. Future revisions in cost estimates or delays in completion could result in additional losses which could reduce future net income and cash flows and impact financial condition. 2017 Merchant Generating Assets (Generation & Marketing Segment) In 2017, AEP recorded an additional pretax impairment of $4 million in Asset Impairments and Other Related Charges on AEP’s statements of income related to Cardinal, Unit 1, a 43.5% interest in Conesville, Unit 4, Conesville, Units 5 and 6, a 26% interest in Stuart, Units 1-4, a 25.4% interest in Zimmer, Unit 1, and a 54.7% interest in Oklaunion (collectively the “Merchant Coal-Fired Generation Assets”). In addition, AEP recorded a $7 million pretax impairment as Asset Impairments and Other Related Charges on AEP’s statements of income related to the sale of Zimmer Plant. The sale is further discussed in the “Disposition” section of this note. Due to a significant increase in estimated costs identified in December 2017 to repair a defective dam structure at Racine, AEP performed an impairment analysis on Racine in accordance with accounting guidance for impairments of long-lived assets. AEP performed step one of the impairment analysis using undiscounted cash flows for the estimated useful life of Racine based upon energy and capacity price curves, which were developed internally with both observable Level 2 third-party quotations and unobservable Level 3 inputs, as well as management’s forecasts of operating expenses and capital expenditures. AEP performed step two of the impairment analysis on Racine using a ten-year discounted cash flow model based upon similar forecasted information used in the step one test. The step two analysis resulted in a fair value determination for Racine of $0 and AEP recorded a pretax impairment of $43 million in Assets Impairments and Other Related Charges on the statements of income in the fourth quarter of 2017. Welsh Plant, Unit 2 and Turk Plant (Vertically Integrated Utilities Segment) (Applies to AEP and SWEPCo) In December 2017, SWEPCo recorded a pretax impairment of $19 million in Asset Impairments and Other Related Charges on the statements of income related to the Texas jurisdictional share of Welsh Plant, Unit 2 and other disallowed plant investments. Additionally in December 2017, SWEPCo recorded a pretax impairment of $15 million in Asset Impairments and Other Related Charges on the statements of income related to the Louisiana jurisdictional share of the Turk Plant. See the “2016 Texas Base Rate Case” section of Note 4 .

Benefit Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2019
Benefit Plans	BENEFIT PLANS The disclosures in this note apply to all Registrants except AEPTCo unless indicated otherwise. For a discussion of investment strategy, investment limitations, target asset allocations and the classification of investments within the fair value hierarchy, see “Fair Value Measurements of Assets and Liabilities” and “Investments Held in Trust for Future Liabilities” sections of Note 1 . AEP sponsors a qualified pension plan and two unfunded nonqualified pension plans. Substantially all AEP employees are covered by the qualified plan or both the qualified and a nonqualified pension plan. AEP also sponsors OPEB plans to provide health and life insurance benefits for retired employees. Due to the Registrant Subsidiaries’ participation in AEP’s benefit plans, the assumptions used by the actuary, with the exception of the rate of compensation increase, and the accounting for the plans by each subsidiary are the same. This section details the assumptions that apply to all Registrants and the rate of compensation increase for each Registrant. The Registrants recognize the funded status associated with defined benefit pension and OPEB plans on the balance sheets. Disclosures about the plans are required by the “Compensation – Retirement Benefits” accounting guidance. The Registrants recognize an asset for a plan’s overfunded status or a liability for a plan’s underfunded status, and recognize, as a component of other comprehensive income, the changes in the funded status of the plan that arise during the year that are not recognized as a component of net periodic benefit cost. The Registrants record a regulatory asset instead of other comprehensive income for qualifying benefit costs of regulated operations that for ratemaking purposes are deferred for future recovery. The cumulative funded status adjustment is equal to the remaining unrecognized deferrals for unamortized actuarial losses or gains, prior service costs and transition obligations, such that remaining deferred costs result in an AOCI equity reduction or regulatory asset and deferred gains result in an AOCI equity addition or regulatory liability. Actuarial Assumptions for Benefit Obligations The weighted-average assumptions used in the measurement of the Registrants’ benefit obligations are shown in the following tables: Pension Plans OPEB December 31, Assumption 2019 2018 2019 2018 Discount Rate 3.25 % 4.30 % 3.30 % 4.30 % Interest Crediting Rate 4.00 % 4.00 % NA NA NA Not applicable. Pension Plans December 31, Assumption – Rate of Compensation Increase (a) 2019 2018 AEP 4.95 % 4.85 % AEP Texas 5.00 % 4.95 % APCo 4.80 % 4.75 % I&M 4.95 % 4.90 % OPCo 5.15 % 5.00 % PSO 5.05 % 4.90 % SWEPCo 4.90 % 4.85 % (a) Rates are for base pay only. In addition, an amount is added to reflect target incentive compensation for exempt employees and overtime and incentive pay for nonexempt employees. A duration-based method is used to determine the discount rate for the plans. A hypothetical portfolio of high quality corporate bonds is constructed with cash flows matching the benefit plan liability. The composite yield on the hypothetical bond portfolio is used as the discount rate for the plan. The discount rate is the same for each Registrant. For 2019 , the rate of compensation increase assumed varies with the age of the employee, ranging from 3% per year to 11.5% per year, with the average increase shown in the table above. The compensation increase rates reflect variations in each Registrants’ population participating in the pension plan. Actuarial Assumptions for Net Periodic Benefit Costs The weighted-average assumptions used in the measurement of each Registrants’ benefit costs are shown in the following tables: Pension Plans OPEB Year Ended December 31, Assumption 2019 2018 2017 2019 2018 2017 Discount Rate 4.30 % 3.65 % 4.05 % 4.30 % 3.60 % 4.10 % Interest Crediting Rate 4.00 % 4.00 % 4.00 % NA NA NA Expected Return on Plan Assets 6.25 % 6.00 % 6.00 % 6.25 % 6.00 % 6.75 % NA Not applicable. Pension Plans Year Ended December 31, Assumption – Rate of Compensation Increase (a) 2019 2018 2017 AEP 4.95 % 4.85 % 4.80 % AEP Texas 5.00 % 4.95 % 4.90 % APCo 4.75 % 4.75 % 4.60 % I&M 4.95 % 4.90 % 4.85 % OPCo 5.20 % 5.00 % 4.95 % PSO 5.05 % 4.90 % 4.90 % SWEPCo 4.90 % 4.85 % 4.80 % (a) Rates are for base pay only. In addition, an amount is added to reflect target incentive compensation for exempt employees and overtime and incentive pay for nonexempt employees. The expected return on plan assets was determined by evaluating historical returns, the current investment climate (yield on fixed income securities and other recent investment market indicators), rate of inflation, third-party forecasts and current prospects for economic growth. The expected return on plan assets is the same for each Registrant. The health care trend rate assumptions used for OPEB plans measurement purposes are shown below: December 31, Health Care Trend Rates 2019 2018 Initial 6.00 % 6.25 % Ultimate 4.50 % 5.00 % Year Ultimate Reached 2026 2024 Significant Concentrations of Risk within Plan Assets In addition to establishing the target asset allocation of plan assets, the investment policy also places restrictions on securities to limit significant concentrations within plan assets. The investment policy establishes guidelines that govern maximum market exposure, security restrictions, prohibited asset classes, prohibited types of transactions, minimum credit quality, average portfolio credit quality, portfolio duration and concentration limits. The guidelines were established to mitigate the risk of loss due to significant concentrations in any investment. Management monitors the plans to control security diversification and ensure compliance with the investment policy. As of December 31, 2019 , the assets were invested in compliance with all investment limits. See “Investments Held in Trust for Future Liabilities” section of Note 1 for limit details. Benefit Plan Obligations, Plan Assets, Funded Status and Amounts Recognized on the Balance Sheets For the year ended December 31, 2019 , the pension plans had an actuarial loss due to a decrease in the discount rate, partially offset by updates to the mortality table. For the year ended December 31, 2019 , the OPEB plans had an actuarial loss due to a decrease in the discount rate and an update to the persistency assumption, partially offset by an update to the projected per capita cost assumption as well as savings resulting from legislation signed in December 2019 which eliminated two Affordable Care Act taxes. For the year ended December 31, 2018 , the pension and OPEB plans had an actuarial gain due to an increase in the discount rate as well as updated estimates for future medical expenses in the OPEB plans. The following tables provide a reconciliation of the changes in the plans’ benefit obligations, fair value of plan assets, funded status and the presentation on the balance sheets. The benefit obligation for the defined benefit pension and OPEB plans are the projected benefit obligation and the accumulated benefit obligation, respectively. AEP Pension Plans OPEB 2019 2018 2019 2018 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 4,810.3 $ 5,215.8 $ 1,194.5 $ 1,332.0 Service Cost 95.5 97.6 9.5 11.6 Interest Cost 204.4 187.8 50.5 47.4 Actuarial (Gain) Loss 493.6 (306.3 ) 58.8 (100.1 ) Plan Amendments 0.2 — (11.0 ) — Benefit Payments (367.2 ) (384.6 ) (113.0 ) (133.6 ) Participant Contributions — — 35.5 36.5 Medicare Subsidy — — 0.6 0.7 Benefit Obligation as of December 31, $ 5,236.8 $ 4,810.3 $ 1,225.4 $ 1,194.5 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 4,695.9 $ 5,174.1 $ 1,534.2 $ 1,732.5 Actual Gain (Loss) on Plan Assets 681.1 (104.9 ) 321.0 (118.3 ) Company Contributions (a) 5.6 11.3 4.1 17.1 Participant Contributions — — 35.5 36.5 Benefit Payments (367.2 ) (384.6 ) (113.0 ) (133.6 ) Fair Value of Plan Assets as of December 31, $ 5,015.4 $ 4,695.9 $ 1,781.8 $ 1,534.2 Funded (Underfunded) Status as of December 31, $ (221.4 ) $ (114.4 ) $ 556.4 $ 339.7 (a) AEP did not make contributions to the qualified pension plan in 2019 or 2018 . Contributions to the nonqualified pension plans were $6 million and $11 million for the years ended December 31, 2019 and 2018 , respectively. Pension Plans OPEB December 31, AEP 2019 2018 2019 2018 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ — $ — $ 590.8 $ 392.2 Other Current Liabilities – Accrued Short-term Benefit Liability (6.1 ) (5.7 ) (2.6 ) (2.8 ) Employee Benefits and Pension Obligations – Accrued Long-term Benefit Liability (215.3 ) (108.7 ) (31.8 ) (49.7 ) Funded (Underfunded) Status $ (221.4 ) $ (114.4 ) $ 556.4 $ 339.7 AEP Texas Pension Plans OPEB 2019 2018 2019 2018 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 409.3 $ 441.3 $ 95.9 $ 107.1 Service Cost 8.6 9.2 0.8 0.9 Interest Cost 17.5 16.0 4.0 3.8 Actuarial (Gain) Loss 40.1 (20.9 ) 3.9 (8.3 ) Plan Amendments — — (0.9 ) — Benefit Payments (34.3 ) (36.3 ) (8.8 ) (10.7 ) Participant Contributions — — 2.9 3.1 Benefit Obligation as of December 31, $ 441.2 $ 409.3 $ 97.8 $ 95.9 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 410.7 $ 455.9 $ 129.9 $ 147.3 Actual Gain (Loss) on Plan Assets 58.3 (9.3 ) 24.0 (14.6 ) Company Contributions 0.4 0.4 0.1 4.8 Participant Contributions — — 2.9 3.1 Benefit Payments (34.3 ) (36.3 ) (8.8 ) (10.7 ) Fair Value of Plan Assets as of December 31, $ 435.1 $ 410.7 $ 148.1 $ 129.9 Funded (Underfunded) Status as of December 31, $ (6.1 ) $ 1.4 $ 50.3 $ 34.0 Pension Plans OPEB December 31, AEP Texas 2019 2018 2019 2018 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ — $ 5.2 $ 50.3 $ 34.0 Other Current Liabilities – Accrued Short-term Benefit Liability (0.4 ) (0.4 ) — — Deferred Credits and Other Noncurrent Liabilities – Accrued Long-term Benefit Liability (5.7 ) (3.4 ) — — Funded (Underfunded) Status $ (6.1 ) $ 1.4 $ 50.3 $ 34.0 APCo Pension Plans OPEB 2019 2018 2019 2018 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 603.1 $ 665.0 $ 205.5 $ 236.5 Service Cost 9.4 9.3 1.0 1.1 Interest Cost 25.2 23.5 8.7 8.2 Actuarial (Gain) Loss 52.9 (49.2 ) 4.7 (21.9 ) Plan Amendments — — (1.7 ) — Benefit Payments (43.4 ) (45.5 ) (20.8 ) (24.7 ) Participant Contributions — — 5.9 6.1 Medicare Subsidy — — 0.2 0.2 Benefit Obligation as of December 31, $ 647.2 $ 603.1 $ 203.5 $ 205.5 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 593.3 $ 651.7 $ 238.4 $ 273.4 Actual Gain (Loss) on Plan Assets 87.1 (12.9 ) 45.3 (18.7 ) Company Contributions — — 2.2 2.3 Participant Contributions — — 5.9 6.1 Benefit Payments (43.4 ) (45.5 ) (20.8 ) (24.7 ) Fair Value of Plan Assets as of December 31, $ 637.0 $ 593.3 $ 271.0 $ 238.4 Funded (Underfunded) Status as of December 31, $ (10.2 ) $ (9.8 ) $ 67.5 $ 32.9 Pension Plans OPEB December 31, APCo 2019 2018 2019 2018 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ — $ — $ 92.0 $ 62.3 Other Current Liabilities – Accrued Short-term Benefit Liability — — (2.0 ) (2.1 ) Employee Benefits and Pension Obligations – Accrued Long-term Benefit Liability (10.2 ) (9.8 ) (22.5 ) (27.3 ) Funded (Underfunded) Status $ (10.2 ) $ (9.8 ) $ 67.5 $ 32.9 I&M Pension Plans OPEB 2019 2018 2019 2018 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 567.0 $ 624.3 $ 138.3 $ 153.5 Service Cost 13.4 13.6 1.4 1.6 Interest Cost 23.8 22.1 5.8 5.4 Actuarial (Gain) Loss 49.8 (53.9 ) 8.1 (10.6 ) Plan Amendments — — (1.5 ) — Benefit Payments (37.9 ) (39.1 ) (13.6 ) (16.2 ) Participant Contributions — — 4.4 4.5 Medicare Subsidy — — — 0.1 Benefit Obligation as of December 31, $ 616.1 $ 567.0 $ 142.9 $ 138.3 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 583.8 $ 636.7 $ 187.3 $ 211.1 Actual Gain (Loss) on Plan Assets 84.6 (13.8 ) 38.2 (12.1 ) Company Contributions — — — — Participant Contributions — — 4.4 4.5 Benefit Payments (37.9 ) (39.1 ) (13.6 ) (16.2 ) Fair Value of Plan Assets as of December 31, $ 630.5 $ 583.8 $ 216.3 $ 187.3 Funded Status as of December 31, $ 14.4 $ 16.8 $ 73.4 $ 49.0 Pension Plans OPEB December 31, I&M 2019 2018 2019 2018 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ 15.8 $ 18.0 $ 73.4 $ 49.0 Deferred Credits and Other Noncurrent Liabilities – Accrued Long-term Benefit Liability (1.4 ) (1.2 ) — — Funded Status $ 14.4 $ 16.8 $ 73.4 $ 49.0 OPCo Pension Plans OPEB 2019 2018 2019 2018 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 453.9 $ 501.1 $ 129.5 $ 144.3 Service Cost 7.9 7.7 0.8 0.9 Interest Cost 19.1 17.7 5.5 5.1 Actuarial (Gain) Loss 40.5 (36.6 ) 4.9 (9.4 ) Plan Amendments — — (1.2 ) — Benefit Payments (33.6 ) (36.0 ) (13.5 ) (15.8 ) Participant Contributions — — 4.1 4.3 Medicare Subsidy — — 0.1 0.1 Benefit Obligation as of December 31, $ 487.8 $ 453.9 $ 130.2 $ 129.5 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 466.1 $ 509.1 $ 175.4 $ 198.5 Actual Gain (Loss) on Plan Assets 66.6 (7.0 ) 31.1 (11.6 ) Participant Contributions — — 4.1 4.3 Benefit Payments (33.6 ) (36.0 ) (13.5 ) (15.8 ) Fair Value of Plan Assets as of December 31, $ 499.1 $ 466.1 $ 197.1 $ 175.4 Funded Status as of December 31, $ 11.3 $ 12.2 $ 66.9 $ 45.9 Pension Plans OPEB December 31, OPCo 2019 2018 2019 2018 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ 11.7 $ 12.6 $ 66.9 $ 45.9 Deferred Credits and Other Noncurrent Liabilities – Accrued Long-term Benefit Liability (0.4 ) (0.4 ) — — Funded Status $ 11.3 $ 12.2 $ 66.9 $ 45.9 PSO Pension Plans OPEB 2019 2018 2019 2018 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 253.8 $ 276.6 $ 62.3 $ 69.4 Service Cost 6.5 7.0 0.6 0.7 Interest Cost 10.6 9.9 2.6 2.5 Actuarial (Gain) Loss 16.8 (18.9 ) 3.8 (5.6 ) Plan Amendments — — (0.7 ) — Benefit Payments (20.2 ) (20.8 ) (5.9 ) (6.7 ) Participant Contributions — — 2.0 2.0 Benefit Obligation as of December 31, $ 267.5 $ 253.8 $ 64.7 $ 62.3 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 261.2 $ 287.8 $ 84.3 $ 95.5 Actual Gain (Loss) on Plan Assets 34.7 (5.9 ) 17.6 (9.2 ) Company Contributions 0.5 0.1 — 2.7 Participant Contributions — — 2.0 2.0 Benefit Payments (20.2 ) (20.8 ) (5.9 ) (6.7 ) Fair Value of Plan Assets as of December 31, $ 276.2 $ 261.2 $ 98.0 $ 84.3 Funded Status as of December 31, $ 8.7 $ 7.4 $ 33.3 $ 22.0 Pension Plans OPEB December 31, PSO 2019 2018 2019 2018 (in millions) Employee Benefits and Pension Assets – Prepaid Benefit Costs $ 10.6 $ 9.7 $ 33.3 $ 22.0 Other Current Liabilities – Accrued Short-term Benefit Liability (0.1 ) (0.2 ) — — Deferred Credits and Other Noncurrent Liabilities – Accrued Long-term Benefit Liability (1.8 ) (2.1 ) — — Funded Status $ 8.7 $ 7.4 $ 33.3 $ 22.0 SWEPCo Pension Plans OPEB 2019 2018 2019 2018 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 291.4 $ 314.6 $ 72.7 $ 80.3 Service Cost 8.6 9.3 0.8 0.9 Interest Cost 12.4 11.3 3.1 2.8 Actuarial (Gain) Loss 25.5 (19.2 ) 6.0 (5.9 ) Plan Amendments — — (0.8 ) — Benefit Payments (23.7 ) (24.6 ) (6.6 ) (7.7 ) Participant Contributions — — 2.2 2.3 Benefit Obligation as of December 31, $ 314.2 $ 291.4 $ 77.4 $ 72.7 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 281.0 $ 311.7 $ 98.5 $ 110.4 Actual Gain (Loss) on Plan Assets 39.5 (7.3 ) 23.1 (9.2 ) Company Contributions 0.1 1.2 — 2.7 Participant Contributions — — 2.2 2.3 Benefit Payments (23.7 ) (24.6 ) (6.6 ) (7.7 ) Fair Value of Plan Assets as of December 31, $ 296.9 $ 281.0 $ 117.2 $ 98.5 Funded (Underfunded) Status as of December 31, $ (17.3 ) $ (10.4 ) $ 39.8 $ 25.8 Pension Plans OPEB December 31, SWEPCo 2019 2018 2019 2018 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ — $ — $ 39.8 $ 25.8 Other Current Liabilities – Accrued Short-term Benefit Liability (0.1 ) (0.2 ) — — Employee Benefits and Pension Obligations – Accrued Long-term Benefit Liability (17.2 ) (10.2 ) — — Funded (Underfunded) Status $ (17.3 ) $ (10.4 ) $ 39.8 $ 25.8 Amounts Included in Regulatory Assets, Deferred Income Taxes and AOCI The following tables show the components of the plans included in Regulatory Assets, Deferred Income Taxes and AOCI and the items attributable to the change in these components: AEP Pension Plans OPEB December 31, 2019 2018 2019 2018 Components (in millions) Net Actuarial Loss $ 1,406.2 $ 1,355.2 $ 225.8 $ 419.8 Prior Service Cost (Credit) 0.2 — (285.7 ) (347.2 ) Recorded as Regulatory Assets $ 1,351.8 $ 1,267.9 $ (46.8 ) $ 52.5 Deferred Income Taxes 11.5 18.4 (2.7 ) 4.2 Net of Tax AOCI 43.1 68.9 (10.4 ) 15.9 AEP Pension Plans OPEB 2019 2018 2019 2018 Components (in millions) Actuarial (Gain) Loss During the Year $ 108.6 $ 88.8 $ (171.9 ) $ 120.4 Amortization of Actuarial Loss (57.6 ) (87.8 ) (22.1 ) (10.5 ) Prior Service (Credit) Cost 0.2 — (7.6 ) — Amortization of Prior Service Credit — — 69.1 69.1 Change for the Year Ended December 31, $ 51.2 $ 1.0 $ (132.5 ) $ 179.0 AEP Texas Pension Plans OPEB December 31, 2019 2018 2019 2018 Components (in millions) Net Actuarial Loss $ 184.7 $ 182.0 $ 23.5 $ 38.0 Prior Service Credit — — (24.2 ) (29.5 ) Recorded as Regulatory Assets $ 172.2 $ 168.2 $ (0.2 ) $ 8.7 Deferred Income Taxes 2.7 2.9 (0.1 ) — Net of Tax AOCI 9.8 10.9 (0.4 ) (0.2 ) AEP Texas Pension Plans OPEB 2019 2018 2019 2018 Components (in millions) Actuarial (Gain) Loss During the Year $ 7.6 $ 14.0 $ (12.7 ) $ 14.9 Amortization of Actuarial Loss (4.9 ) (7.2 ) (1.8 ) (0.8 ) Prior Service Credit — — (0.6 ) — Amortization of Prior Service Credit — — 5.9 5.9 Change for the Year Ended December 31, $ 2.7 $ 6.8 $ (9.2 ) $ 20.0 APCo Pension Plans OPEB December 31, 2019 2018 2019 2018 Components (in millions) Net Actuarial Loss $ 168.3 $ 172.2 $ 28.8 $ 58.9 Prior Service Credit — — (41.6 ) (50.4 ) Recorded as Regulatory Assets $ 166.3 $ 169.6 $ (5.5 ) $ 2.6 Deferred Income Taxes 0.3 0.5 (1.5 ) 1.2 Net of Tax AOCI 1.7 2.1 (5.8 ) 4.7 APCo Pension Plans OPEB 2019 2018 2019 2018 Components (in millions) Actuarial (Gain) Loss During the Year $ 3.1 $ 0.3 $ (26.4 ) $ 12.8 Amortization of Actuarial Loss (7.0 ) (10.6 ) (3.7 ) (1.9 ) Prior Service Credit — — (1.3 ) — Amortization of Prior Service Credit — — 10.1 10.0 Change for the Year Ended December 31, $ (3.9 ) $ (10.3 ) $ (21.3 ) $ 20.9 I&M Pension Plans OPEB December 31, 2019 2018 2019 2018 Components (in millions) Net Actuarial Loss $ 76.0 $ 80.6 $ 32.7 $ 54.7 Prior Service Credit — — (39.0 ) (47.4 ) Recorded as Regulatory Assets $ 73.7 $ 78.4 $ (6.2 ) $ 6.5 Deferred Income Taxes 0.5 0.5 — 0.2 Net of Tax AOCI 1.8 1.7 (0.1 ) 0.6 I&M Pension Plans OPEB 2019 2018 2019 2018 Components (in millions) Actuarial (Gain) Loss During the Year $ 2.0 $ (4.5 ) $ (19.3 ) $ 13.9 Amortization of Actuarial Loss (6.6 ) (9.8 ) (2.7 ) (1.2 ) Prior Service Credit — — (1.0 ) — Amortization of Prior Service Credit — — 9.4 9.5 Change for the Year Ended December 31, $ (4.6 ) $ (14.3 ) $ (13.6 ) $ 22.2 OPCo Pension Plans OPEB December 31, 2019 2018 2019 2018 Components (in millions) Net Actuarial Loss $ 178.7 $ 180.7 $ 17.2 $ 35.5 Prior Service Credit — — (28.6 ) (34.7 ) Recorded as Regulatory Assets $ 178.7 $ 180.7 $ (11.4 ) $ 0.8 OPCo Pension Plans OPEB 2019 2018 2019 2018 Components (in millions) Actuarial (Gain) Loss During the Year $ 3.3 $ (0.9 ) $ (15.8 ) $ 14.0 Amortization of Actuarial Loss (5.3 ) (8.0 ) (2.5 ) (1.1 ) Prior Service Credit — — (0.8 ) — Amortization of Prior Service Credit — — 6.9 6.9 Change for the Year Ended December 31, $ (2.0 ) $ (8.9 ) $ (12.2 ) $ 19.8 PSO Pension Plans OPEB December 31, 2019 2018 2019 2018 Components (in millions) Net Actuarial Loss $ 73.0 $ 77.6 $ 18.2 $ 28.3 Prior Service Credit — — (17.8 ) (21.6 ) Recorded as Regulatory Assets $ 73.0 $ 77.6 $ 0.4 $ 6.7 PSO Pension Plans OPEB 2019 2018 2019 2018 Components (in millions) Actuarial (Gain) Loss During the Year $ (1.7 ) $ 3.2 $ (8.9 ) $ 9.0 Amortization of Actuarial Loss (2.9 ) (4.4 ) (1.2 ) (0.5 ) Prior Service Credit — — (0.5 ) — Amortization of Prior Service Credit — — 4.3 4.3 Change for the Year Ended December 31, $ (4.6 ) $ (1.2 ) $ (6.3 ) $ 12.8 SWEPCo Pension Plans OPEB December 31, 2019 2018 2019 2018 Components (in millions) Net Actuarial Loss $ 97.8 $ 97.4 $ 21.1 $ 33.9 Prior Service Credit — — (21.6 ) (26.2 ) Recorded as Regulatory Assets $ 97.8 $ 97.4 $ — $ 4.9 Deferred Income Taxes — — — 0.7 Net of Tax AOCI — — (0.5 ) 2.1 SWEPCo Pension Plans OPEB 2019 2018 2019 2018 Components (in millions) Actuarial (Gain) Loss During the Year $ 3.8 $ 5.5 $ (11.4 ) $ 9.8 Amortization of Actuarial Loss (3.4 ) (5.5 ) (1.4 ) (0.6 ) Prior Service Credit — — (0.6 ) — Amortization of Prior Service Credit — — 5.2 5.2 Change for the Year Ended December 31, $ 0.4 $ — $ (8.2 ) $ 14.4 Determination of Pension Expense The determination of pension expense or income is based on a market-related valuation of assets which reduces year-to-year volatility. This market-related valuation recognizes investment gains or losses over a five-year period from the year in which they occur. Investment gains or losses for this purpose are the difference between the expected return calculated using the market-related value of assets and the actual return. Pension and OPEB Assets The fair value tables within Pension and OPEB Assets present the classification of assets for AEP within the fair value hierarchy. All Level 1, 2, 3 and Other amounts can be allocated to the Registrant Subsidiaries using the percentages in the table below: Pension Plan OPEB December 31, Company 2019 2018 2019 2018 AEP Texas 8.7 % 8.7 % 8.3 % 8.5 % APCo 12.7 % 12.6 % 15.2 % 15.5 % I&M 12.6 % 12.4 % 12.1 % 12.2 % OPCo 10.0 % 9.9 % 11.1 % 11.4 % PSO 5.5 % 5.6 % 5.5 % 5.5 % SWEPCo 5.9 % 6.0 % 6.6 % 6.4 % The following table presents the classification of pension plan assets for AEP within the fair value hierarchy as of December 31, 2019 : Asset Class Level 1 Level 2 Level 3 Other Total Year End Allocation (in millions) Equities (a): Domestic $ 387.8 $ — $ — $ — $ 387.8 7.8 % International 609.1 — — — 609.1 12.1 % Common Collective Trusts (c) — — — 547.3 547.3 10.9 % Subtotal – Equities 996.9 — — 547.3 1,544.2 30.8 % Fixed Income (a): United States Government and Agency Securities (5.8 ) 1,248.6 — — 1,242.8 24.8 % Corporate Debt — 1,143.7 — — 1,143.7 22.8 % Foreign Debt — 211.6 — — 211.6 4.2 % State and Local Government — 55.1 — — 55.1 1.1 % Other – Asset Backed — 3.6 — — 3.6 0.1 % Subtotal – Fixed Income (5.8 ) 2,662.6 — — 2,656.8 53.0 % Infrastructure (c) — — — 85.8 85.8 1.7 % Real Estate (c) — — — 239.4 239.4 4.8 % Alternative Investments (c) — — — 448.3 448.3 8.9 % Cash and Cash Equivalents (c) — 24.4 — 37.2 61.6 1.2 % Other – Pending Transactions and Accrued Income (b) — — — (20.7 ) (20.7 ) (0.4 )% Total $ 991.1 $ 2,687.0 $ — $ 1,337.3 $ 5,015.4 100.0 % (a) Includes investment securities loaned to borrowers under the securities lending program. See the “Investments Held in Trust for Future Liabilities” section of Note 1 for additional information. (b) Amounts in “Other” column primarily represent accrued interest, dividend receivables and transactions pending settlement. (c) Amounts in “Other” column represent investments for which fair value is measured using net asset value per share. The following table presents the classification of OPEB plan assets for AEP within the fair value hierarchy as of December 31, 2019 : Asset Class Level 1 Level 2 Level 3 Other Total Year End Allocation (in millions) Equities: Domestic $ 312.2 $ — $ — $ — $ 312.2 17.5 % International 251.5 — — — 251.5 14.1 % Common Collective Trusts (b) — — — 260.8 260.8 14.7 % Subtotal – Equities 563.7 — — 260.8 824.5 46.3 % Fixed Income: Common Collective Trust – Debt (b) — — — 177.6 177.6 10.0 % United States Government and Agency Securities (0.1 ) 214.4 — — 214.3 12.0 % Corporate Debt — 206.7 — — 206.7 11.6 % Foreign Debt — 35.5 — — 35.5 2.0 % State and Local Government 58.8 14.8 — — 73.6 4.1 % Other – Asset Backed — 0.2 — — 0.2 — % Subtotal – Fixed Income 58.7 471.6 — 177.6 707.9 39.7 % Trust Owned Life Insurance: International Equities — 60.2 — — 60.2 3.4 % United States Bonds — 151.6 — — 151.6 8.5 % Subtotal – Trust Owned Life Insurance — 211.8 — — 211.8 11.9 % Cash and Cash Equivalents (b) 26.7 — — 6.7 33.4 1.9 % Other – Pending Transactions and Accrued Income (a) — — — 4.2 4.2 0.2 % Total $ 649.1 $ 683.4 $ — $ 449.3 $ 1,781.8 100.0 % (a) Amounts in “Other” column primarily represent accrued interest, dividend receivables and transactions pending settlement. (b) Amounts in “Other” column represent investments for which fair value is measured using net asset value per share. The following table presents the classification of pension plan assets for AEP within the fair value hierarchy as of December 31, 2018 : Asset Class Level 1 Level 2 Level 3 Other Total Year End (in millions) Equities (a): Domestic $ 277.3 $ — $ — $ — $ 277.3 5.9 % International 384.1 — — — 384.1 8.2 % Options — 18.3 — — 18.3 0.4 % Common Collective Trusts (c) — — — 370.1 370.1 7.9 % Subtotal – Equities 661.4 18.3 — 370.1 1,049.8 22.4 % Fixed Income (a): United States Government and Agency Securities 0.2 1,512.5 — — 1,512.7 32.2 % Corporate Debt — 1,082.9 — — 1,082.9 23.0 % Foreign Debt — 221.6 — — 221.6 4.7 % State and Local Government — 28.2 — — 28.2 0.6 % Other – Asset Backed — 7.4 — — 7.4 0.2 % Subtotal – Fixed Income 0.2 2,852.6 — — 2,852.8 60.7 % Infrastructure (c) — — — 72.2 72.2 1.5 % Real Estate (c) — — — 220.4 220.4 4.7 % Alternative Investments (c) — — — 444.6 444.6 9.5 % Cash and Cash Equivalents (c) (0.4 ) 36.3 — 11.9 47.8 1.0 % Other – Pending Transactions and Accrued Income (b) — — — 8.3 8.3 0.2 % Total $ 661.2 $ 2,907.2 $ — $ 1,127.5 $ 4,695.9 100.0 % (a) Includes investment securities loaned to borrowers under the securities lending program. See the “Investments Held in Trust for Future Liabilities” section of Note 1 for additional information. (b) Amounts in “Other” column primarily represent accrued interest, dividend receivables and transactions pending settlement. (c) Amounts in “Other” column represent investments for which fair value is measured using net asset value per share. The following table presents the classification of OPEB plan assets for AEP within the fair value hierarchy as of December 31, 2018 : Asset Class Level 1 Level 2 Level 3 Other Total Year End (in millions) Equities: Domestic $ 233.3 $ — $ — $ — $ 233.3 15.2 % International 185.9 — — — 185.9 12.1 % Options — 4.3 — — 4.3 0.3 % Common Collective Trusts (b) — — — 226.2 226.2 14.7 % Subtotal – Equities 419.2 4.3 — 226.2 649.7 42.3 % Fixed Income: Common Collective Trust – Debt (b) — — — 163.6 163.6 10.7 % United States Government and Agency Securities 0.2 181.5 — — 181.7 11.8 % Corporate Debt — 188.6 — — 188.6 12.3 % Foreign Debt — 35.0 — — 35.0 2.3 % State and Local Government 41.8 11.8 — — 53.6 3.5 % Other – Asset Backed — 0.2 — — 0.2 — % Subtotal – Fixed Income 42.0 417.1 — 163.6 622.7 40.6 % Trust Owned Life Insurance: International Equities — 49.4 — — 49.4 3.2 % United States Bonds — 154.4 — — 154.4 10.1 % Subtotal – Trust Owned Life Insurance — 203.8 — — 203.8 13.3 % Cash and Cash Equivalents (b) 54.4 — — 4.8 59.2 3.9 % Other – Pending Transactions and Accrued Income (a) — — — (1.2 ) (1.2 ) (0.1 )% Total $ 515.6 $ 625.2 $ — $ 393.4 $ 1,534.2 100.0 % (a) Amounts in “Other” column primarily represent accrued interest, dividend receivables and transactions pending settlement. (b) Amounts in “Other” column represent investments for which fair value is measured using net asset value per share. Accumulated Benefit Obligation The accumulated benefit obligation for the pension plans is as follows: Accumulated Benefit Obligation AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Qualified Pension Plan $ 4,929.0 $ 417.5 $ 627.3 $ 586.3 $ 464.2 $ 248.9 $ 291.9 Nonqualified Pension Plans 69.7 3.6 0.2 0.6 0.1 1.6 1.3 Total as of December 31, 2019 $ 4,998.7 $ 421.1 $ 627.5 $ 586.9 $ 464.3 $ 250.5 $ 293.2 Accumulated Benefit Obligation AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Qualified Pension Plan $ 4,560.7 $ 393.2 $ 588.3 $ 536.3 $ 438.3 $ 238.0 $ 271.6 Nonqualified Pension Plans 64.9 3.6 0.2 0.6 0.2 2.2 1.2 Total as of December 31, 2018 $ 4,625.6 $ 396.8 $ 588.5 $ 536.9 $ 438.5 $ 240.2 $ 272.8 Obligations in Excess of Fair Values The tables below show the underfunded pension plans that had obligations in excess of plan assets. Projected Benefit Obligation AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Projected Benefit Obligation $ 5,236.8 $ 441.2 $ 647.2 $ 1.5 $ 0.4 $ 1.9 $ 314.2 Fair Value of Plan Assets 5,015.4 435.1 637.0 — — — 296.9 Underfunded Projected Benefit Obligation as of December 31, 2019 $ (221.4 ) $ (6.1 ) $ (10.2 ) $ (1.5 ) $ (0.4 ) $ (1.9 ) $ (17.3 ) AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Projected Benefit Obligation $ 4,810.3 $ 3.8 $ 603.1 $ 1.2 $ 0.4 $ 2.3 $ 291.4 Fair Value of Plan Assets 4,695.9 — 593.3 — — — 281.0 Underfunded Projected Benefit Obligation as of December 31, 2018 $ (114.4 ) $ (3.8 ) $ (9.8 ) $ (1.2 ) $ (0.4 ) $ (2.3 ) $ (10.4 ) Accumulated Benefit Obligation AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Accumulated Benefit Obligation $ 69.7 $ 3.6 $ 0.2 $ 0.6 $ 0.1 $ 1.6 $ 1.3 Fair Value of Plan Assets — — — — — — — Underfunded Accumulated Benefit Obligation as of December 31, 2019 $ (69.7 ) $ (3.6 ) $ (0.2 ) $ (0.6 ) $ (0.1 ) $ (1.6 ) $ (1.3 ) AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Accumulated Benefit Obligation $ 64.9 $ 3.6 $ 0.2 $ 0.6 $ 0.2 $ 2.2 $ 1.2 Fair Value of Plan Assets — — — — — — — Underfunded Accumulated Benefit Obligation as of December 31, 2018 $ (64.9 ) $ (3.6 ) $ (0.2 ) $ (0.6 ) $ (0.2 ) $ (2.2 ) $ (1.2 ) Estimated Future Benefit Payments and Contributions The estimated pension benefit payments and contributions to the trust are at least the minimum amount required by the Employee Retirement Income Security Act plus payment of unfunded nonqualified benefits. For the qualified pension plan, additional discretionary contributions may also be made to maintain the funded status of the plan. For OPEB plans, expected payments include the payment of unfunded benefits. The following table provides the estimated contributions and payments by Registrant for 2020 : Company Pension Plans OPEB (in millions) AEP $ 6.1 $ 3.4 AEP Texas 0.4 0.1 APCo — 2.0 I&M — — OPCo — — PSO 0.1 — SWEPCo 0.1 — The tables below reflect the total benefits expected to be paid from the plan or from the Registrants’ assets. The payments include the participants’ contributions to the plan for their share of the cost. Future benefit payments are dependent on the number of employees retiring, whether the retiring employees elect to receive pension benefits as annuities or as lump sum distributions, future integration of the benefit plans with changes to Medicare and other legislation, future levels of interest rates and variances in actuarial results. The estimated payments for the pension benefits and OPEB are as follows: Pension Plans AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) 2020 $ 378.1 $ 37.5 $ 45.8 $ 40.1 $ 36.2 $ 20.9 $ 24.0 2021 382.8 37.3 46.0 40.5 36.1 21.3 24.7 2022 380.5 35.9 45.7 42.5 35.7 21.2 25.2 2023 383.8 36.6 46.1 42.2 35.8 22.6 25.4 2024 382.9 36.3 46.8 42.8 34.0 21.5 25.8 Years 2025 to 2029, in Total 1,800.7 162.2 217.4 211.6 161.1 98.3 119.6 OPEB Benefit Payments AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) 2020 $ 126.3 $ 10.0 $ 22.5 $ 15.2 $ 14.8 $ 6.8 $ 7.5 2021 124.0 10.0 21.8 15.2 14.2 6.7 7.7 2022 125.2 10.4 21.6 15.5 14.4 6.9 8.0 2023 125.0 10.6 21.2 15.5 14.3 7.0 8.2 2024 124.6 10.7 21.1 15.4 14.1 7.1 8.4 Years 2025 to 2029, in Total 592.6 50.8 97.8 72.8 65.4 33.7 40.6 OPEB Medicare Subsidy Receipts AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) 2020 $ 0.2 $ — $ 0.1 $ — $ — $ — $ — 2021 0.3 — 0.2 — — — — 2022 0.3 — 0.2 — — — — 2023 0.3 — 0.1 — — — — 2024 0.3 — 0.1 — — — — Years 2025 to 2029, in Total 1.4 — 0.6 — — — — Components of Net Periodic Benefit Cost The following tables provide the components of net periodic benefit cost (credit) by Registrant for the plans: AEP Pension Plans OPEB Years Ended December 31, 2019 2018 2017 2019 2018 2017 (in millions) Service Cost $ 95.5 $ 97.6 $ 96.5 $ 9.5 $ 11.6 $ 11.2 Interest Cost 204.4 187.8 203.1 50.5 47.4 59.3

Business Segments

Business Segments	12 Months Ended
	Dec. 31, 2019
Business Segments	BUSINESS SEGMENTS The disclosures in this note apply to all Registrants unless indicated otherwise. AEP’s Reportable Segments AEP’s primary business is the generation, transmission and distribution of electricity. Within its Vertically Integrated Utilities segment, AEP centrally dispatches generation assets and manages its overall utility operations on an integrated basis because of the substantial impact of cost-based rates and regulatory oversight. Intersegment sales and transfers are generally based on underlying contractual arrangements and agreements. AEP’s reportable segments and their related business activities are outlined below: Vertically Integrated Utilities • Generation, transmission and distribution of electricity for sale to retail and wholesale customers through assets owned and operated by AEGCo, APCo, I&M, KGPCo, KPCo, PSO, SWEPCo and WPCo. Transmission and Distribution Utilities • Transmission and distribution of electricity for sale to retail and wholesale customers through assets owned and operated by AEP Texas and OPCo. • OPCo purchases energy and capacity at auction to serve SSO customers and provides transmission and distribution services for all connected load. AEP Transmission Holdco • Development, construction and operation of transmission facilities through investments in AEPTCo. These investments have FERC-approved returns on equity. • Development, construction and operation of transmission facilities through investments in AEP’s transmission-only joint ventures. These investments have PUCT-approved or FERC-approved returns on equity. Generation & Marketing • Contracted renewable energy investments and management services. • Competitive generation in ERCOT and PJM. • Marketing, risk management and retail activities in ERCOT, PJM, SPP and MISO. The remainder of AEP’s activities are presented as Corporate and Other. While not considered a reportable segment, Corporate and Other primarily includes the purchasing of receivables from certain AEP utility subsidiaries, Parent’s guarantee revenue received from affiliates, investment income, interest income, interest expense, income tax expense and other nonallocated costs. The tables below present AEP’s reportable segment income statement information for the years ended December 31, 2019 , 2018 and 2017 and reportable segment balance sheet information as of December 31, 2019 and 2018 . Vertically Integrated Utilities Transmission and Distribution Utilities AEP Transmission Holdco Generation & Marketing Corporate and Other (a) Reconciling Adjustments Consolidated (in millions) 2019 Revenues from: External Customers $ 9,245.7 $ 4,319.0 $ 260.2 $ 1,721.8 $ 14.7 $ — $ 15,561.4 Other Operating Segments 121.4 163.5 813.0 135.8 81.1 (1,314.8 ) — Total Revenues $ 9,367.1 $ 4,482.5 $ 1,073.2 $ 1,857.6 $ 95.8 $ (1,314.8 ) $ 15,561.4 Asset Impairments and Other Related Charges $ 92.9 $ 32.5 $ — $ 31.0 $ — $ — $ 156.4 Depreciation and Amortization 1,447.0 789.5 183.4 69.5 0.6 24.5 (b) 2,514.5 Interest Expense 568.3 243.3 103.3 30.0 193.7 (66.1 ) (b) 1,072.5 Income Tax Expense (Benefit) (97.7 ) (25.2 ) 136.2 (53.8 ) 27.6 — (12.9 ) Equity Earnings (Loss) of Unconsolidated Subsidiaries 3.0 — 72.8 (3.8 ) 0.1 — 72.1 Net Income (Loss) $ 985.6 $ 451.0 $ 520.1 $ 104.1 $ (141.0 ) $ — $ 1,919.8 Gross Property Additions $ 2,437.4 $ 2,074.3 $ 1,458.9 $ 1,005.1 $ 14.5 $ (20.4 ) $ 6,969.8 Total Property, Plant and Equipment $ 47,323.7 $ 19,773.3 $ 10,334.0 $ 1,650.8 $ 418.4 $ (354.5 ) (b) $ 79,145.7 Accumulated Depreciation and Amortization 14,580.4 3,911.2 418.9 99.0 184.5 (186.4 ) (b) 19,007.6 Total Property, Plant and Equipment – Net $ 32,743.3 $ 15,862.1 $ 9,915.1 $ 1,551.8 $ 233.9 $ (168.1 ) (b) $ 60,138.1 Total Assets $ 41,228.8 $ 18,757.5 $ 11,143.5 $ 3,123.8 $ 5,440.0 (c) $ (3,801.3 ) (b) (d) $ 75,892.3 Investments in Equity Method Investees $ 41.7 $ 2.5 $ 787.5 $ 459.5 $ 65.4 $ — $ 1,356.6 Long-term Debt Due Within One Year: Affiliated $ 20.0 $ — $ — $ — $ — $ (20.0 ) $ — Nonaffiliated 704.7 392.2 — — 501.8 (e) — 1,598.7 Long-term Debt: Affiliated 39.0 — — — — (39.0 ) — Nonaffiliated 12,162.0 6,248.1 3,593.8 — 3,122.9 (e) — 25,126.8 Total Long-term Debt $ 12,925.7 $ 6,640.3 $ 3,593.8 $ — $ 3,624.7 $ (59.0 ) $ 26,725.5 Vertically Integrated Utilities Transmission and Distribution Utilities AEP Transmission Holdco Generation & Marketing Corporate and Other (a) Reconciling Adjustments Consolidated (in millions) 2018 Revenues from: External Customers $ 9,556.7 $ 4,552.3 $ 248.6 $ 1,818.1 $ 20.0 $ — $ 16,195.7 Other Operating Segments 88.8 100.8 555.5 122.2 75.1 (942.4 ) — Total Revenues $ 9,645.5 $ 4,653.1 $ 804.1 $ 1,940.3 $ 95.1 $ (942.4 ) $ 16,195.7 Asset Impairments and Other Related Charges $ 3.4 $ — $ — $ 47.7 $ 19.5 $ — $ 70.6 Depreciation and Amortization 1,316.2 734.1 137.8 41.0 0.4 57.1 (b) 2,286.6 Interest Expense 567.8 248.1 90.7 14.9 122.6 (59.7 ) (b) 984.4 Income Tax Expense (Benefit) 5.7 42.4 95.3 (49.2 ) 21.1 — 115.3 Equity Earnings of Unconsolidated Subsidiaries 2.7 — 68.7 0.5 1.2 — 73.1 Net Income (Loss) $ 995.5 $ 527.4 $ 373.0 $ 134.7 $ (99.3 ) $ — $ 1,931.3 Gross Property Additions $ 2,282.2 $ 2,162.4 $ 1,614.1 $ 289.7 $ 16.3 $ (39.2 ) $ 6,325.5 Total Property, Plant and Equipment $ 45,365.1 $ 18,126.7 $ 8,659.5 $ 893.3 $ 395.2 $ (354.6 ) (b) $ 73,085.2 Accumulated Depreciation and Amortization 13,822.5 3,833.7 282.8 47.0 186.6 (186.5 ) (b) 17,986.1 Total Property, Plant and Equipment – Net $ 31,542.6 $ 14,293.0 $ 8,376.7 $ 846.3 $ 208.6 $ (168.1 ) (b) $ 55,099.1 Total Assets $ 38,874.3 $ 17,083.4 $ 9,543.7 $ 1,979.7 $ 4,036.5 (c) $ (2,714.8 ) (b) (d) $ 68,802.8 Investments in Equity Method Investees $ 39.6 $ 2.9 $ 750.9 $ 26.7 $ 26.1 $ — $ 846.2 Long-term Debt Due Within One Year: Nonaffiliated $ 1,066.3 $ 549.1 $ 85.0 $ 0.1 $ (2.0 ) (e) $ — $ 1,698.5 Long-term Debt: Affiliated 50.0 — — 32.2 — (82.2 ) — Nonaffiliated 11,442.7 5,048.8 2,888.6 (0.3 ) 2,268.4 — 21,648.2 Total Long-term Debt $ 12,559.0 $ 5,597.9 $ 2,973.6 $ 32.0 $ 2,266.4 (e) $ (82.2 ) $ 23,346.7 Vertically Integrated Utilities Transmission and Distribution Utilities AEP Transmission Holdco Generation & Marketing Corporate and Other(a) Reconciling Adjustments Consolidated (in millions) 2017 Revenues from: External Customers $ 9,095.1 $ 4,328.9 $ 178.4 $ 1,771.4 $ 51.1 $ — $ 15,424.9 Other Operating Segments 96.9 90.4 588.3 103.7 69.7 (949.0 ) — Total Revenues $ 9,192.0 $ 4,419.3 $ 766.7 $ 1,875.1 $ 120.8 $ (949.0 ) $ 15,424.9 Asset Impairments and Other Related Charges $ 33.6 $ — $ — $ 53.5 $ — $ — $ 87.1 Depreciation and Amortization 1,142.5 667.5 102.2 24.2 0.3 60.5 (b) 1,997.2 Interest Expense 540.0 244.1 72.8 18.5 63.9 (44.3 ) (b) 895.0 Income Tax Expense 425.6 127.2 189.8 189.7 37.4 — 969.7 Equity Earnings (Loss) of Unconsolidated Subsidiaries $ (3.8 ) $ — $ 88.6 $ — $ (2.4 ) $ — $ 82.4 Net Income (Loss) $ 803.3 $ 636.4 $ 355.6 $ 166.0 $ (32.4 ) $ — $ 1,928.9 Gross Property Additions $ 2,343.2 $ 1,558.4 $ 1,542.8 $ 328.5 $ 15.6 $ (90.4 ) $ 5,698.1 Total Assets $ 37,579.7 $ 16,060.7 $ 8,141.8 $ 2,009.8 $ 3,959.1 (c) $ (3,022.0 ) (b) (d) $ 64,729.1 (a) Corporate and Other primarily includes the purchasing of receivables from certain AEP utility subsidiaries. This segment also includes Parent’s guarantee revenue received from affiliates, investment income, interest income, interest expense and other nonallocated costs. (b) Includes eliminations due to an intercompany finance lease. (c) Includes elimination of AEP Parent’s investments in wholly-owned subsidiary companies. (d) Reconciling Adjustments for Total Assets primarily include elimination of intercompany advances to affiliates and intercompany accounts receivable. (e) Amounts reflect the impact of fair value hedge accounting. See “Accounting for Fair Value Hedging Strategies” section of Note 10 for additional information. Registrant Subsidiaries’ Reportable Segments (Applies to all Registrant Subsidiaries except AEPTCo) The Registrant Subsidiaries each have one reportable segment, an integrated electricity generation, transmission and distribution business for APCo, I&M, PSO and SWEPCo, and an integrated electricity transmission and distribution business for AEP Texas and OPCo. Other activities are insignificant. The Registrant Subsidiaries’ operations are managed on an integrated basis because of the substantial impact of cost-based rates and regulatory oversight on the business process, cost structures and operating results. AEPTCo’s Reportable Segments AEPTCo Parent is the holding company of seven FERC-regulated transmission-only electric utilities. The seven State Transcos have been identified as operating segments of AEPTCo under the accounting guidance for “Segment Reporting.” The State Transcos business consists of developing, constructing and operating transmission facilities at the request of the RTOs in which they operate and in replacing and upgrading facilities, assets and components of the existing AEP transmission system as needed to maintain reliability standards and provide service to AEP’s wholesale and retail customers. The State Transcos are regulated for rate-making purposes exclusively by the FERC and earn revenues through tariff rates charged for the use of their electric transmission systems. AEPTCo’s Chief Operating Decision Maker makes operating decisions, allocates resources to and assesses performance based on these operating segments. The seven State Transcos operating segments all have similar economic characteristics and meet all of the criteria under the accounting guidance for “Segment Reporting” to be aggregated into one operating segment. As a result, AEPTCo has one reportable segment. The remainder of AEPTCo’s activity is presented in AEPTCo Parent. While not considered a reportable segment, AEPTCo Parent represents the activity of the holding company which primarily relates to debt financing activity and general corporate activities. The tables below present AEPTCo’s reportable segment income statement information for the years ended December 31, 2019 , 2018 and 2017 and reportable segment balance sheet information as of December 31, 2019 and 2018 . State Transcos AEPTCo Parent Reconciling Adjustments AEPTCo Consolidated 2019 (in millions) Revenues from: External Customers $ 214.6 $ — $ — $ 214.6 Sales to AEP Affiliates 806.7 — — 806.7 Other Revenues 0.1 — — 0.1 Total Revenues $ 1,021.4 $ — $ — $ 1,021.4 Depreciation and Amortization $ 176.0 $ — $ — $ 176.0 Interest Income 1.3 123.8 (122.1 ) (a) 3.0 Allowance for Equity Funds Used During Construction 84.3 — — 84.3 Interest Expense 97.4 122.1 (122.1 ) (a) 97.4 Income Tax Expense 117.1 0.3 — 117.4 Net Income $ 438.6 $ 1.1 (b) $ — $ 439.7 Gross Property Additions $ 1,419.5 $ — $ — $ 1,419.5 Total Transmission Property $ 9,893.2 $ — $ — $ 9,893.2 Accumulated Depreciation and Amortization 402.3 — — 402.3 Total Transmission Property - Net $ 9,490.9 $ — $ — $ 9,490.9 Notes Receivable - Affiliated $ — $ 3,427.3 $ (3,427.3 ) (c) $ — Total Assets $ 9,865.0 $ 3,519.1 (d) $ (3,493.3 ) (e) $ 9,890.8 Total Long-Term Debt $ 3,465.0 $ 3,427.3 $ (3,465.0 ) (c) $ 3,427.3 State Transcos AEPTCo Parent Reconciling Adjustments AEPTCo Consolidated 2018 (in millions) Revenues from: External Customers $ 177.0 $ — $ — $ 177.0 Sales to AEP Affiliates 598.9 — — 598.9 Other Revenues 0.2 — — 0.2 Total Revenues $ 776.1 $ — $ — $ 776.1 Depreciation and Amortization $ 133.9 $ — $ — $ 133.9 Interest Income 1.3 104.6 (103.4 ) (a) 2.5 Allowance for Equity Funds Used During Construction 70.6 — — 70.6 Interest Expense 83.2 103.4 (103.4 ) (a) 83.2 Income Tax Expense 83.9 0.2 — 84.1 Net Income $ 314.9 $ 1.0 (b) $ — $ 315.9 Gross Property Additions $ 1,570.8 $ — $ — $ 1,570.8 Total Transmission Property $ 8,268.1 $ — $ — $ 8,268.1 Accumulated Depreciation and Amortization 271.9 — — 271.9 Total Transmission Property - Net $ 7,996.2 $ — $ — $ 7,996.2 Notes Receivable - Affiliated $ — $ 2,823.0 $ (2,823.0 ) (c) $ — Total Assets $ 8,406.8 $ 2,857.1 (d) $ (2,869.8 ) (e) $ 8,394.1 Total Long-Term Debt $ 2,850.0 $ 2,823.0 $ (2,850.0 ) (c) $ 2,823.0 ` State Transcos AEPTCo Parent Reconciling Adjustments AEPTCo Consolidated 2017 (in millions) Revenues from: External Customers $ 138.0 $ — $ — $ 138.0 Sales to AEP Affiliates 568.1 — — 568.1 Other 0.8 — — 0.8 Total Revenues $ 706.9 $ — $ — $ 706.9 Depreciation and Amortization $ 95.7 $ — $ — $ 95.7 Interest Income 0.7 82.9 (82.4 ) (a) 1.2 Allowance for Equity Funds Used During Construction 49.0 — — 49.0 Interest Expense 70.2 82.4 (82.4 ) (a) 70.2 Income Tax Expense (Benefit) 142.0 0.2 — 142.2 Net Income (Loss) $ 270.4 $ 0.3 (b) $ — $ 270.7 Gross Property Additions $ 1,522.5 $ — $ — $ 1,522.5 Total Assets $ 7,086.9 $ 2,590.1 (d) $ (2,594.9 ) (e) $ 7,082.1 (a) Elimination of intercompany interest income/interest expense on affiliated debt arrangement. (b) Includes elimination of AEPTCo Parent’s equity earnings in the State Transcos. (c) Elimination of intercompany debt. (d) Includes elimination of AEPTCo Parent’s investments in the State Transcos. (e) Primarily relates to elimination of Notes Receivable from the State Transcos.

Derivatives and Hedging

Derivatives and Hedging	12 Months Ended
	Dec. 31, 2019
Derivatives and Hedging	DERIVATIVES AND HEDGING The disclosures in this note apply to all Registrants unless indicated otherwise. For the periods presented, AEPTCo did not have any derivative and hedging activity. OBJECTIVES FOR UTILIZATION OF DERIVATIVE INSTRUMENTS AEPSC is agent for and transacts on behalf of AEP subsidiaries, including the Registrant Subsidiaries. AEPEP is agent for and transacts on behalf of other AEP subsidiaries. The Registrants are exposed to certain market risks as major power producers and participants in the electricity, capacity, natural gas, coal and emission allowance markets. These risks include commodity price risks which may be subject to capacity risk, interest rate risk and credit risk. These risks represent the risk of loss that may impact the Registrants due to changes in the underlying market prices or rates. Management utilizes derivative instruments to manage these risks. STRATEGIES FOR UTILIZATION OF DERIVATIVE INSTRUMENTS TO ACHIEVE OBJECTIVES Risk Management Strategies The strategy surrounding the use of derivative instruments primarily focuses on managing risk exposures, future cash flows and creating value utilizing both economic and formal hedging strategies. The risk management strategies also include the use of derivative instruments for trading purposes which focus on seizing market opportunities to create value driven by expected changes in the market prices of the commodities. To accomplish these objectives, the Registrants primarily employ risk management contracts including physical and financial forward purchase-and-sale contracts and, to a lesser extent, OTC swaps and options. Not all risk management contracts meet the definition of a derivative under the accounting guidance for “Derivatives and Hedging.” Derivative risk management contracts elected normal under the normal purchases and normal sales scope exception are not subject to the requirements of this accounting guidance. The Registrants utilize power, capacity, coal, natural gas, interest rate and, to a lesser extent, heating oil, gasoline and other commodity contracts to manage the risk associated with the energy business. The Registrants utilize interest rate derivative contracts in order to manage the interest rate exposure associated with the commodity portfolio. For disclosure purposes, such risks are grouped as “Commodity,” as these risks are related to energy risk management activities. The Registrants also utilize derivative contracts to manage interest rate risk associated with debt financing. For disclosure purposes, these risks are grouped as “Interest Rate.” The amount of risk taken is determined by the Commercial Operations, Energy Supply and Finance groups in accordance with established risk management policies as approved by the Finance Committee of the Board of Directors. The following tables represent the gross notional volume of the Registrants’ outstanding derivative contracts: Notional Volume of Derivative Instruments December 31, 2019 Primary Risk Exposure Unit of Measure AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Commodity: Power MWhs 365.9 — 61.0 26.8 7.1 14.9 4.4 Natural Gas MMBtus 40.7 — — — — — 11.6 Heating Oil and Gasoline Gallons 6.9 1.8 1.1 0.6 1.4 0.7 0.9 Interest Rate USD $ 140.1 $ — $ — $ — $ — $ — $ — Interest Rate on Long-term Debt USD $ 625.0 $ — $ — $ — $ — $ — $ — December 31, 2018 Primary Risk Exposure Unit of Measure AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Commodity: Power MWhs 371.1 — 66.4 40.9 7.8 15.2 4.5 Natural Gas MMBtus 87.9 — 4.0 2.3 — — 15.2 Heating Oil and Gasoline Gallons 7.4 1.5 1.4 0.7 1.8 0.7 0.8 Interest Rate USD $ 37.7 $ — $ — $ — $ — $ — $ — Interest Rate on Long-term Debt USD $ 500.0 $ — $ — $ — $ — $ — $ — Fair Value Hedging Strategies (Applies to AEP) Parent enters into interest rate derivative transactions as part of an overall strategy to manage the mix of fixed-rate and floating-rate debt. Certain interest rate derivative transactions effectively modify exposure to interest rate risk by converting a portion of fixed-rate debt to a floating rate. Provided specific criteria are met, these interest rate derivatives may be designated as fair value hedges. Cash Flow Hedging Strategies The Registrants utilize cash flow hedges on certain derivative transactions for the purchase and sale of power (“Commodity”) in order to manage the variable price risk related to forecasted purchases and sales. Management monitors the potential impacts of commodity price changes and, where appropriate, enters into derivative transactions to protect profit margins for a portion of future electricity sales and purchases. The Registrants do not hedge all commodity price risk. The Registrants utilize a variety of interest rate derivative transactions in order to manage interest rate risk exposure. The Registrants also utilize interest rate derivative contracts to manage interest rate exposure related to future borrowings of fixed-rate debt. The Registrants do not hedge all interest rate exposure. ACCOUNTING FOR DERIVATIVE INSTRUMENTS AND THE IMPACT ON THE FINANCIAL STATEMENTS The accounting guidance for “Derivatives and Hedging” requires recognition of all qualifying derivative instruments as either assets or liabilities on the balance sheets at fair value. The fair values of derivative instruments accounted for using MTM accounting or hedge accounting are based on exchange prices and broker quotes. If a quoted market price is not available, the estimate of fair value is based on the best information available including valuation models that estimate future energy prices based on existing market and broker quotes, supply and demand market data and assumptions. In order to determine the relevant fair values of the derivative instruments, the Registrants apply valuation adjustments for discounting, liquidity and credit quality. Credit risk is the risk that a counterparty will fail to perform on the contract or fail to pay amounts due. Liquidity risk represents the risk that imperfections in the market will cause the price to vary from estimated fair value based upon prevailing market supply and demand conditions. Since energy markets are imperfect and volatile, there are inherent risks related to the underlying assumptions in models used to fair value risk management contracts. Unforeseen events may cause reasonable price curves to differ from actual price curves throughout a contract’s term and at the time a contract settles. Consequently, there could be significant adverse or favorable effects on future net income and cash flows if market prices are not consistent with management’s estimates of current market consensus for forward prices in the current period. This is particularly true for longer term contracts. Cash flows may vary based on market conditions, margin requirements and the timing of settlement of risk management contracts. According to the accounting guidance for “Derivatives and Hedging,” the Registrants reflect the fair values of derivative instruments subject to netting agreements with the same counterparty net of related cash collateral. For certain risk management contracts, the Registrants are required to post or receive cash collateral based on third-party contractual agreements and risk profiles. AEP netted cash collateral received from third-parties against short-term and long-term risk management assets in the amounts of $5 million and $18 million as of December 31, 2019 and 2018 , respectively. AEP netted cash collateral paid to third-parties against short-term and long-term risk management liabilities in the amounts of $39 million and $4 million as of December 31, 2019 and 2018 , respectively. The netted cash collateral from third-parties against short-term and long-term risk management assets and netted cash collateral paid to third-parties against short-term and long-term risk management liabilities were immaterial for the other Registrants as of December 31, 2019 and 2018 . The following tables represent the gross fair value of the Registrants’ derivative activity on the balance sheets: AEP Fair Value of Derivative Instruments December 31, 2019 Risk Management Contracts Hedging Contracts Gross Amounts of Risk Management Assets/ Liabilities Recognized Gross Amounts Offset in the Statement of Financial Position (b) Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position (c) Balance Sheet Location Commodity (a) Commodity (a) Interest Rate (a) (in millions) Current Risk Management Assets $ 513.9 $ 11.5 $ 6.5 $ 531.9 $ (359.1 ) $ 172.8 Long-term Risk Management Assets 290.8 11.0 12.6 314.4 (47.8 ) 266.6 Total Assets 804.7 22.5 19.1 846.3 (406.9 ) 439.4 Current Risk Management Liabilities 424.5 72.3 — 496.8 (382.5 ) 114.3 Long-term Risk Management Liabilities 244.5 75.7 — 320.2 (58.4 ) 261.8 Total Liabilities 669.0 148.0 — 817.0 (440.9 ) 376.1 Total MTM Derivative Contract Net Assets (Liabilities) $ 135.7 $ (125.5 ) $ 19.1 $ 29.3 $ 34.0 $ 63.3 December 31, 2018 Risk Management Contracts Hedging Contracts Gross Amounts of Risk Management Assets/ Liabilities Recognized Gross Amounts Offset in the Statement of Financial Position (b) Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position (c) Balance Sheet Location Commodity (a) Commodity (a) Interest Rate (a) (in millions) Current Risk Management Assets $ 397.5 $ 28.5 $ — $ 426.0 $ (263.2 ) $ 162.8 Long-term Risk Management Assets 276.4 16.0 — 292.4 (38.4 ) 254.0 Total Assets 673.9 44.5 — 718.4 (301.6 ) 416.8 Current Risk Management Liabilities 293.8 13.2 2.0 309.0 (254.0 ) 55.0 Long-term Risk Management Liabilities 225.7 56.1 15.4 297.2 (33.8 ) 263.4 Total Liabilities 519.5 69.3 17.4 606.2 (287.8 ) 318.4 Total MTM Derivative Contract Net Assets (Liabilities) $ 154.4 $ (24.8 ) $ (17.4 ) $ 112.2 $ (13.8 ) $ 98.4 AEP Texas Fair Value of Derivative Instruments December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ — $ — $ — Long-term Risk Management Assets — — — Total Assets — — — Current Risk Management Liabilities — — — Long-term Risk Management Liabilities — — — Total Liabilities — — — Total MTM Derivative Contract Net Assets $ — $ — $ — December 31, 2018 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ — $ — $ — Long-term Risk Management Assets — — — Total Assets — — — Current Risk Management Liabilities 0.7 (0.5 ) 0.2 Long-term Risk Management Liabilities — — — Total Liabilities 0.7 (0.5 ) 0.2 Total MTM Derivative Contract Net Assets (Liabilities) $ (0.7 ) $ 0.5 $ (0.2 ) APCo Fair Value of Derivative Instruments December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ 124.4 $ (85.0 ) $ 39.4 Long-term Risk Management Assets 0.9 (0.8 ) 0.1 Total Assets 125.3 (85.8 ) 39.5 Current Risk Management Liabilities 86.2 (84.3 ) 1.9 Long-term Risk Management Liabilities 0.7 (0.7 ) — Total Liabilities 86.9 (85.0 ) 1.9 Total MTM Derivative Contract Net Assets (Liabilities) $ 38.4 $ (0.8 ) $ 37.6 December 31, 2018 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ 114.4 $ (57.2 ) $ 57.2 Long-term Risk Management Assets 3.1 (2.2 ) 0.9 Total Assets 117.5 (59.4 ) 58.1 Current Risk Management Liabilities 56.7 (56.3 ) 0.4 Long-term Risk Management Liabilities 2.4 (2.2 ) 0.2 Total Liabilities 59.1 (58.5 ) 0.6 Total MTM Derivative Contract Net Assets (Liabilities) $ 58.4 $ (0.9 ) $ 57.5 I&M Fair Value of Derivative Instruments December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ 66.9 $ (57.1 ) $ 9.8 Long-term Risk Management Assets 0.5 (0.4 ) 0.1 Total Assets 67.4 (57.5 ) 9.9 Current Risk Management Liabilities 55.2 (54.7 ) 0.5 Long-term Risk Management Liabilities 0.4 (0.4 ) — Total Liabilities 55.6 (55.1 ) 0.5 Total MTM Derivative Contract Net Assets (Liabilities) $ 11.8 $ (2.4 ) $ 9.4 December 31, 2018 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ 50.4 $ (41.8 ) $ 8.6 Long-term Risk Management Assets 2.0 (1.4 ) 0.6 Total Assets 52.4 (43.2 ) 9.2 Current Risk Management Liabilities 41.1 (40.8 ) 0.3 Long-term Risk Management Liabilities 1.6 (1.5 ) 0.1 Total Liabilities 42.7 (42.3 ) 0.4 Total MTM Derivative Contract Net Assets (Liabilities) $ 9.7 $ (0.9 ) $ 8.8 OPCo Fair Value of Derivative Instruments December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ — $ — $ — Long-term Risk Management Assets — — — Total Assets — — — Current Risk Management Liabilities 7.3 — 7.3 Long-term Risk Management Liabilities 96.3 — 96.3 Total Liabilities 103.6 — 103.6 Total MTM Derivative Contract Net Liabilities $ (103.6 ) $ — $ (103.6 ) December 31, 2018 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ — $ — $ — Long-term Risk Management Assets — — — Total Assets — — — Current Risk Management Liabilities 6.4 (0.6 ) 5.8 Long-term Risk Management Liabilities 93.8 — 93.8 Total Liabilities 100.2 (0.6 ) 99.6 Total MTM Derivative Contract Net Assets (Liabilities) $ (100.2 ) $ 0.6 $ (99.6 ) PSO Fair Value of Derivative Instruments December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ 16.3 $ (0.5 ) $ 15.8 Long-term Risk Management Assets — — — Total Assets 16.3 (0.5 ) 15.8 Current Risk Management Liabilities 0.5 (0.5 ) — Long-term Risk Management Liabilities — — — Total Liabilities 0.5 (0.5 ) — Total MTM Derivative Contract Net Assets $ 15.8 $ — $ 15.8 December 31, 2018 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ 10.9 $ (0.5 ) $ 10.4 Long-term Risk Management Assets — — — Total Assets 10.9 (0.5 ) 10.4 Current Risk Management Liabilities 1.7 (0.7 ) 1.0 Long-term Risk Management Liabilities — — — Total Liabilities 1.7 (0.7 ) 1.0 Total MTM Derivative Contract Net Assets $ 9.2 $ 0.2 $ 9.4 SWEPCo Fair Value of Derivative Instruments December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ 6.5 $ (0.1 ) $ 6.4 Long-term Risk Management Assets — — — Total Assets 6.5 (0.1 ) 6.4 Current Risk Management Liabilities 2.0 (0.1 ) 1.9 Long-term Risk Management Liabilities 3.1 — 3.1 Total Liabilities 5.1 (0.1 ) 5.0 Total MTM Derivative Contract Net Assets $ 1.4 $ — $ 1.4 December 31, 2018 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ 5.6 $ (0.8 ) $ 4.8 Long-term Risk Management Assets — — — Total Assets 5.6 (0.8 ) 4.8 Current Risk Management Liabilities 1.5 (1.1 ) 0.4 Long-term Risk Management Liabilities 2.2 — 2.2 Total Liabilities 3.7 (1.1 ) 2.6 Total MTM Derivative Contract Net Assets $ 1.9 $ 0.3 $ 2.2 (a) Derivative instruments within these categories are reported gross. These instruments are subject to master netting agreements and are presented on the balance sheets on a net basis in accordance with the accounting guidance for “Derivatives and Hedging.” (b) Amounts include counterparty netting of risk management and hedging contracts and associated cash collateral in accordance with the accounting guidance for “Derivatives and Hedging.” (c) All derivative contracts subject to a master netting arrangement or similar agreement are offset in the statement of financial position. The tables below present the Registrants’ activity of derivative risk management contracts: Amount of Gain (Loss) Recognized on Risk Management Contracts Year Ended December 31, 2019 Location of Gain (Loss) AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Vertically Integrated Utilities Revenues $ 0.7 $ — $ — $ — $ — $ — $ — Generation & Marketing Revenues 25.1 — — — — — — Electric Generation, Transmission and Distribution Revenues — — 0.1 0.5 — — 0.1 Purchased Electricity for Resale 1.9 — 1.6 0.1 — — — Other Operation (0.8 ) (0.2 ) (0.1 ) (0.1 ) (0.2 ) (0.1 ) (0.1 ) Maintenance (0.8 ) (0.2 ) (0.2 ) (0.1 ) (0.2 ) (0.1 ) (0.1 ) Regulatory Assets (a) (3.7 ) 0.7 0.3 0.3 (3.7 ) 1.2 (1.5 ) Regulatory Liabilities (a) 102.6 — 2.4 24.5 10.1 34.6 26.6 Total Gain on Risk Management Contracts $ 125.0 $ 0.3 $ 4.1 $ 25.2 $ 6.0 $ 35.6 $ 25.0 Amount of Gain (Loss) Recognized on Risk Management Contracts Year Ended December 31, 2018 Location of Gain (Loss) AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Vertically Integrated Utilities Revenues $ (10.4 ) $ — $ — $ — $ — $ — $ — Generation & Marketing Revenues 38.9 — — — — — — Electric Generation, Transmission and Distribution Revenues — — (1.9 ) (8.2 ) — — 0.1 Purchased Electricity for Resale 8.6 — 7.6 0.8 — — — Other Operation 1.7 0.4 0.2 0.2 0.3 0.2 0.2 Maintenance 1.9 0.4 0.4 0.2 0.4 0.2 0.2 Regulatory Assets (a) 27.9 (0.7 ) (0.7 ) 7.1 24.9 (1.1 ) (1.2 ) Regulatory Liabilities (a) 222.7 (0.5 ) 135.5 11.6 — 37.3 11.9 Total Gain (Loss) on Risk Management Contracts $ 291.3 $ (0.4 ) $ 141.1 $ 11.7 $ 25.6 $ 36.6 $ 11.2 Amount of Gain (Loss) Recognized on Risk Management Contracts Year Ended December 31, 2017 Location of Gain (Loss) AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Vertically Integrated Utilities Revenues $ 6.1 $ — $ — $ — $ — $ — $ — Generation & Marketing Revenues 42.8 — — — — — — Electric Generation, Transmission and Distribution Revenues — — 0.6 5.3 — — 0.1 Purchased Electricity for Resale 5.6 — 2.0 0.6 — — — Other Operation 0.8 0.1 0.1 0.1 0.1 0.1 0.1 Maintenance 0.7 0.2 0.1 0.1 0.1 0.1 0.1 Regulatory Assets (a) (29.4 ) — — (7.4 ) (22.0 ) — 0.3 Regulatory Liabilities (a) 109.4 0.1 40.4 15.9 — 24.8 24.3 Total Gain (Loss) on Risk Management Contracts $ 136.0 $ 0.4 $ 43.2 $ 14.6 $ (21.8 ) $ 25.0 $ 24.9 (a) Represents realized and unrealized gains and losses subject to regulatory accounting treatment recorded as either current or noncurrent on the balance sheets. Certain qualifying derivative instruments have been designated as normal purchase or normal sale contracts, as provided in the accounting guidance for “Derivatives and Hedging.” Derivative contracts that have been designated as normal purchases or normal sales under that accounting guidance are not subject to MTM accounting treatment and are recognized on the statements of income on an accrual basis. The accounting for the changes in the fair value of a derivative instrument depends on whether it qualifies for and has been designated as part of a hedging relationship and further, on the type of hedging relationship. Depending on the exposure, management designates a hedging instrument as a fair value hedge or a cash flow hedge. For contracts that have not been designated as part of a hedging relationship, the accounting for changes in fair value depends on whether the derivative instrument is held for trading purposes. Unrealized and realized gains and losses on derivative instruments held for trading purposes are included in revenues on a net basis on the statements of income. Unrealized and realized gains and losses on derivative instruments not held for trading purposes are included in revenues or expenses on the statements of income depending on the relevant facts and circumstances. Certain derivatives that economically hedge future commodity risk are recorded in the same expense line item on the statements of income as that of the associated risk. However, unrealized and some realized gains and losses in regulated jurisdictions for both trading and non-trading derivative instruments are recorded as regulatory assets (for losses) or regulatory liabilities (for gains) in accordance with the accounting guidance for “Regulated Operations.” Accounting for Fair Value Hedging Strategies (Applies to AEP) For fair value hedges (i.e. hedging the exposure to changes in the fair value of an asset, liability or an identified portion thereof attributable to a particular risk), the gain or loss on the derivative instrument as well as the offsetting gain or loss on the hedged item associated with the hedged risk impacts net income during the period of change. AEP records realized and unrealized gains or losses on interest rate swaps that are designated and qualify for fair value hedge accounting treatment and any offsetting changes in the fair value of the debt being hedged in Interest Expense on the statements of income. The following table shows the impacts recognized on the balance sheets related to the hedged items in fair value hedging relationships: Carrying Amount of the Hedged Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Assets/(Liabilities) December 31, 2019 December 31, 2018 December 31, 2019 December 31, 2018 (in millions) Long-term Debt (a) $ (510.8 ) $ (478.3 ) $ (14.5 ) $ 17.4 (a) Amounts included on the balance sheets within Long-term Debt Due within One Year and Long-term Debt, respectively. The pretax effects of fair value hedge accounting on income were as follows: Twelve Months Ended December 31, 2019 2018 2017 (in millions) Gain (Loss) on Interest Rate Contracts: Gain (Loss) on Fair Value Hedging Instruments (a) $ 31.9 $ (11.3 ) $ (4.8 ) Gain (Loss) on Fair Value Portion of Long-term Debt (a) (31.9 ) 11.3 4.8 (a) Gain (Loss) is included in Interest Expense on the statements of income. Accounting for Cash Flow Hedging Strategies For cash flow hedges (i.e. hedging the exposure to variability in expected future cash flows that is attributable to a particular risk), the Registrants initially report the gain or loss on the derivative instrument as a component of Accumulated Other Comprehensive Income (Loss) on the balance sheets until the period the hedged item affects net income. Realized gains and losses on derivative contracts for the purchase and sale of power designated as cash flow hedges are included in Total Revenues or Purchased Electricity for Resale on the statements of income or in Regulatory Assets or Regulatory Liabilities on the balance sheets, depending on the specific nature of the risk being hedged. During the years ended 2019 , 2018 and 2017 , AEP applied cash flow hedging to outstanding power derivatives. During the years ended 2019 , 2018 and 2017 , the Registrant Subsidiaries did not apply cash flow hedging to outstanding power derivatives. The Registrants reclassify gains and losses on interest rate derivative hedges related to debt financings from Accumulated Other Comprehensive Income (Loss) on the balance sheets into Interest Expense on the statements of income in those periods in which hedged interest payments occur. During the years ended 2019 , 2018 and 2017 , AEP applied cash flow hedging to outstanding interest rate derivatives. During the years ended 2019 and 2017 , the Registrant Subsidiaries did not apply cash flow hedging to outstanding interest rate derivatives. During the year ended 2018, SWEPCo applied cash flow hedging to outstanding interest rate derivatives and the other Registrant Subsidiaries did not. For details on effective cash flow hedges included in Accumulated Other Comprehensive Income (Loss) on the balance sheets and the reasons for changes in cash flow hedges, see Note 3 - Comprehensive Income. Cash flow hedges included in Accumulated Other Comprehensive Income (Loss) on the balance sheets were: Impact of Cash Flow Hedges on AEP’s Balance Sheets December 31, 2019 December 31, 2018 Commodity Interest Rate Commodity Interest Rate (in millions) AOCI Gain (Loss) Net of Tax $ (103.5 ) $ (11.5 ) (a) $ (23.0 ) $ (12.6 ) Portion Expected to be Reclassed to Net Income During the Next Twelve Months (51.7 ) (2.1 ) 10.4 (1.1 ) (a) Includes $4 million related to AEP's investment in joint venture wind farms acquired as part of the purchase of Sempra Renewables LLC. See “Sempra Renewables LLC” section of Note 17 for additional information. As of December 31, 2019 the maximum length of time that AEP is hedging its exposure to variability in future cash flows related to forecasted transactions is 120 months and 132 months for commodity and interest rate hedges, respectively. Impact of Cash Flow Hedges on the Registrant Subsidiaries’ Balance Sheets December 31, 2019 December 31, 2018 Interest Rate Expected to be Expected to be Reclassified to Reclassified to Net Income During Net Income During AOCI Gain (Loss) the Next AOCI Gain (Loss) the Next Company Net of Tax Twelve Months Net of Tax Twelve Months (in millions) AEP Texas $ (3.4 ) $ (1.1 ) $ (4.4 ) $ (1.1 ) APCo 0.9 0.9 1.8 0.9 I&M (9.9 ) (1.6 ) (11.5 ) (1.6 ) OPCo — — 1.0 1.0 PSO 1.1 1.0 2.1 1.0 SWEPCo (1.8 ) (1.5 ) (3.3 ) (1.5 ) The actual amounts reclassified from Accumulated Other Comprehensive Income (Loss) to Net Income can differ from the estimate above due to market price changes. Credit Risk Management mitigates credit risk in wholesale marketing and trading activities by assessing the creditworthiness of potential counterparties before entering into transactions with them and continuing to evaluate their creditworthiness on an ongoing basis. Management uses credit agency ratings and current market-based qualitative and quantitative data as well as financial statements to assess the financial health of counterparties on an ongoing basis. Master agreements are typically used to facilitate the netting of cash flows associated with a single counterparty and may include collateral requirements. Collateral requirements in the form of cash, letters of credit and parental/affiliate guarantees may be obtained as security from counterparties in order to mitigate credit risk. Some master agreements include margining, which requires a counterparty to post cash or letters of credit in the event exposure exceeds the established threshold. The threshold represents an unsecured credit limit which may be supported by a parental/affiliate guaranty, as determined in accordance with AEP’s credit policy. In addition, master agreements allow for termination and liquidation of all positions in the event of a default including a failure or inability to post collateral when required. Collateral Triggering Events Credit Downgrade Triggers (Applies to AEP, APCo, I&M, PSO and SWEPCo) A limited number of derivative contracts include collateral triggering events, which include a requirement to maintain certain credit ratings. On an ongoing basis, AEP’s risk management organization assesses the appropriateness of these collateral triggering events in contracts. The Registrants have not experienced a downgrade below a specified credit rating threshold that would require the posting of additional collateral. The Registrants had no derivative contracts with collateral triggering events in a net liability position as of December 31, 2019 and 2018 . Cross-Default Triggers (Applies to AEP, APCo, I&M and SWEPCo) In addition, a majority of non-exchange-traded commodity contracts contain cross-default provisions that, if triggered, would permit the counterparty to declare a default and require settlement of the outstanding payable. These cross-default provisions could be triggered if there was a non-performance event by Parent or the obligor under outstanding debt or a third-party obligation that is $50 million or greater. On an ongoing basis, AEP’s risk management organization assesses the appropriateness of these cross-default provisions in the contracts. The following tables represent: (a) the fair value of these derivative liabilities subject to cross-default provisions prior to consideration of contractual netting arrangements, (b) the amount that the exposure has been reduced by cash collateral posted and (c) if a cross-default provision would have been triggered, the settlement amount that would be required after considering contractual netting arrangements: December 31, 2019 Liabilities for Additional Contracts with Cross Settlement Default Provisions Liability if Cross Prior to Contractual Amount of Cash Default Provision Company Netting Arrangements Collateral Posted is Triggered (in millions) AEP $ 267.3 $ 3.7 $ 246.7 APCo 2.3 — 0.4 I&M 1.3 — 0.2 SWEPCo 5.1 — 5.1 December 31, 2018 Liabilities for Additional Contracts with Cross Settlement Default Provisions Liability if Cross Prior to Contractual Amount of Cash Default Provision Company Netting Arrangements Collateral Posted is Triggered (in millions) AEP $ 225.5 $ 1.8 $ 181.0 APCo 0.9 — — I&M 0.5 — — SWEPCo 2.3 — 2.3

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2019
Fair Value Measurements	FAIR VALUE MEASUREMENTS The disclosures in this note apply to all Registrants except AEPTCo unless indicated otherwise. Fair Value Measurements of Long-term Debt (Applies to all Registrants) The fair values of Long-term Debt are based on quoted market prices, without credit enhancements, for the same or similar issues and the current interest rates offered for instruments with similar maturities classified as Level 2 measurement inputs. These instruments are not marked-to-market. The estimates presented are not necessarily indicative of the amounts that could be realized in a current market exchange. The fair value of AEP’s Equity Units (Level 1) are valued based on publicly traded securities issued by AEP. The book values and fair values of Long-term Debt are summarized in the following table: December 31, 2019 2018 Company Book Value Fair Value Book Value Fair Value (in millions) AEP (a) $ 26,725.5 $ 30,172.0 $ 23,346.7 $ 24,093.9 AEP Texas 4,558.4 4,981.5 3,881.3 3,964.6 AEPTCo 3,427.3 3,868.0 2,823.0 2,782.4 APCo 4,363.8 5,253.1 4,062.6 4,473.3 I&M 3,050.2 3,453.8 3,035.4 3,070.2 OPCo 2,082.0 2,554.3 1,716.6 1,919.7 PSO 1,386.2 1,603.3 1,287.0 1,361.9 SWEPCo 2,655.6 2,927.9 2,713.4 2,670.2 (a) The fair value amount includes debt related to AEP’s Equity Units issued in March 2019 and had a fair value of $871 million as of December 31, 2019 . See “Equity Units” section of Note 14 for additional information. Fair Value Measurements of Other Temporary Investments (Applies to AEP) Other Temporary Investments include marketable securities that management intends to hold for less than one year and investments by AEP’s protected cell of EIS. See “Other Temporary Investments” section of Note 1 for additional information. The following is a summary of Other Temporary Investments: December 31, 2019 Gross Gross Unrealized Unrealized Fair Other Temporary Investments Cost Gains Losses Value (in millions) Restricted Cash and Other Cash Deposits (a) $ 214.7 $ — $ — $ 214.7 Fixed Income Securities – Mutual Funds (b) 123.2 0.1 — 123.3 Equity Securities – Mutual Funds 29.2 21.3 — 50.5 Total Other Temporary Investments $ 367.1 $ 21.4 $ — $ 388.5 December 31, 2018 Gross Gross Unrealized Unrealized Fair Other Temporary Investments Cost Gains Losses Value (in millions) Restricted Cash and Other Cash Deposits (a) $ 230.6 $ — $ — $ 230.6 Fixed Income Securities – Mutual Funds (b) 106.6 — (2.3 ) 104.3 Equity Securities – Mutual Funds 17.8 16.4 — 34.2 Total Other Temporary Investments $ 355.0 $ 16.4 $ (2.3 ) $ 369.1 (a) Primarily represents amounts held for the repayment of debt. (b) Primarily short and intermediate maturities which may be sold and do not contain maturity dates. The following table provides the activity for fixed income and equity securities within Other Temporary Investments: Years Ended December 31, 2019 2018 2017 (in millions) Proceeds from Investment Sales $ 21.2 $ — $ — Purchases of Investments 45.0 3.1 14.2 Gross Realized Gains on Investment Sales — — — Gross Realized Losses on Investment Sales 0.4 — — For details of the reasons for changes in Securities Available for Sale included in Accumulated Other Comprehensive Income (Loss) for the years ended December 31, 2018 and 2017 , see Note 3 - Comprehensive Income. Fair Value Measurements of Trust Assets for Decommissioning and SNF Disposal (Applies to AEP and I&M) Securities held in trust funds for decommissioning nuclear facilities and for the disposal of SNF are recorded at fair value. See “Nuclear Trust Funds” section of Note 1 . The following is a summary of nuclear trust fund investments: December 31, 2019 2018 Gross Other-Than- Gross Other-Than- Fair Unrealized Temporary Fair Unrealized Temporary Value Gains Impairments Value Gains Impairments (in millions) Cash and Cash Equivalents $ 15.3 $ — $ — $ 22.5 $ — $ — Fixed Income Securities: United States Government 1,112.5 55.5 (6.1 ) 996.1 26.7 (7.1 ) Corporate Debt 72.4 5.3 (1.6 ) 52.4 1.1 (1.9 ) State and Local Government 7.6 0.7 (0.2 ) 8.6 0.6 (0.2 ) Subtotal Fixed Income Securities 1,192.5 61.5 (7.9 ) 1,057.1 28.4 (9.2 ) Equity Securities - Domestic (a) 1,767.9 1,144.4 — 1,395.3 766.3 — Spent Nuclear Fuel and Decommissioning Trusts $ 2,975.7 $ 1,205.9 $ (7.9 ) $ 2,474.9 $ 794.7 $ (9.2 ) (a) Amount reported as Gross Unrealized Gains includes unrealized gains of $1.1 billion and $784 million and unrealized losses of $5 million and $18 million as of December 31, 2019 and 2018 , respectively. AEP adopted ASU 2016-01 during the first quarter of 2018 by means of a modified retrospective approach. Due to the adoption of the ASU, Other-Than-Temporary Impairments are no longer applicable to Equity Securities with readily determinable fair values. The following table provides the securities activity within the decommissioning and SNF trusts: Years Ended December 31, 2019 2018 2017 (in millions) Proceeds from Investment Sales $ 1,473.0 $ 2,010.0 $ 2,256.3 Purchases of Investments 1,531.0 2,064.7 2,300.5 Gross Realized Gains on Investment Sales 76.5 47.5 200.7 Gross Realized Losses on Investment Sales 24.3 32.8 146.0 The base cost of fixed income securities was $1.1 billion and $1 billion as of December 31, 2019 and 2018 , respectively. The base cost of equity securities was $623 million and $629 million as of December 31, 2019 and 2018 , respectively. The fair value of fixed income securities held in the nuclear trust funds, summarized by contractual maturities, as of December 31, 2019 was as follows: Fair Value of Fixed Income Securities (in millions) Within 1 year $ 371.0 After 1 year through 5 years 386.2 After 5 years through 10 years 217.3 After 10 years 218.0 Total $ 1,192.5 Fair Value Measurements of Financial Assets and Liabilities For a discussion of fair value accounting and the classification of assets and liabilities within the fair value hierarchy, see the “Fair Value Measurements of Assets and Liabilities” section of Note 1 . The following tables set forth, by level within the fair value hierarchy, the Registrants’ financial assets and liabilities that were accounted for at fair value on a recurring basis. As required by the accounting guidance for “Fair Value Measurements and Disclosures,” financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. Management’s assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy levels. There have not been any significant changes in management’s valuation techniques. AEP Assets and Liabilities Measured at Fair Value on a Recurring Basis December 31, 2019 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Other Temporary Investments Restricted Cash and Other Cash Deposits (a) $ 197.6 $ — $ — $ 17.1 $ 214.7 Fixed Income Securities – Mutual Funds 123.3 — — — 123.3 Equity Securities – Mutual Funds (b) 50.5 — — — 50.5 Total Other Temporary Investments 371.4 — — 17.1 388.5 Risk Management Assets Risk Management Commodity Contracts (c) (d) 4.0 440.1 369.2 (404.5 ) 408.8 Cash Flow Hedges: Commodity Hedges (c) — 15.0 3.2 (6.7 ) 11.5 Interest Rate Hedges — 4.6 — — 4.6 Fair Value Hedges — 14.5 — — 14.5 Total Risk Management Assets 4.0 474.2 372.4 (411.2 ) 439.4 Spent Nuclear Fuel and Decommissioning Trusts Cash and Cash Equivalents (e) 6.7 — — 8.6 15.3 Fixed Income Securities: United States Government — 1,112.5 — — 1,112.5 Corporate Debt — 72.4 — — 72.4 State and Local Government — 7.6 — — 7.6 Subtotal Fixed Income Securities — 1,192.5 — — 1,192.5 Equity Securities – Domestic (b) 1,767.9 — — — 1,767.9 Total Spent Nuclear Fuel and Decommissioning Trusts 1,774.6 1,192.5 — 8.6 2,975.7 Total Assets $ 2,150.0 $ 1,666.7 $ 372.4 $ (385.5 ) $ 3,803.6 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (d) $ 3.8 $ 450.0 $ 224.0 $ (438.8 ) $ 239.0 Cash Flow Hedges: Commodity Hedges (c) — 105.3 38.5 (6.7 ) 137.1 Total Risk Management Liabilities $ 3.8 $ 555.3 $ 262.5 $ (445.5 ) $ 376.1 AEP Assets and Liabilities Measured at Fair Value on a Recurring Basis December 31, 2018 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Other Temporary Investments Restricted Cash and Other Cash Deposits (a) $ 221.5 $ — $ — $ 9.1 $ 230.6 Fixed Income Securities – Mutual Funds 104.3 — — — 104.3 Equity Securities – Mutual Funds (b) 34.2 — — — 34.2 Total Other Temporary Investments 360.0 — — 9.1 369.1 Risk Management Assets Risk Management Commodity Contracts (c) (f) 3.8 326.5 340.9 (288.5 ) 382.7 Cash Flow Hedges: Commodity Hedges (c) — 24.1 12.7 (2.7 ) 34.1 Total Risk Management Assets 3.8 350.6 353.6 (291.2 ) 416.8 Spent Nuclear Fuel and Decommissioning Trusts Cash and Cash Equivalents (e) 12.3 — — 10.2 22.5 Fixed Income Securities: United States Government — 996.1 — — 996.1 Corporate Debt — 52.4 — — 52.4 State and Local Government — 8.6 — — 8.6 Subtotal Fixed Income Securities — 1,057.1 — — 1,057.1 Equity Securities – Domestic (b) 1,395.3 — — — 1,395.3 Total Spent Nuclear Fuel and Decommissioning Trusts 1,407.6 1,057.1 — 10.2 2,474.9 Total Assets $ 1,771.4 $ 1,407.7 $ 353.6 $ (271.9 ) $ 3,260.8 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (f) $ 4.2 $ 327.0 $ 185.6 $ (274.7 ) $ 242.1 Cash Flow Hedges: Commodity Hedges (c) — 24.8 36.8 (2.7 ) 58.9 Fair Value Hedges — 17.4 — — 17.4 Total Risk Management Liabilities $ 4.2 $ 369.2 $ 222.4 $ (277.4 ) $ 318.4 AEP Texas Assets and Liabilities Measured at Fair Value on a Recurring Basis December 31, 2019 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 154.7 $ — $ — $ — $ 154.7 December 31, 2018 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 156.7 $ — $ — $ — $ 156.7 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) $ — $ 0.7 $ — $ (0.5 ) $ 0.2 APCo Assets and Liabilities Measured at Fair Value on a Recurring Basis December 31, 2019 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 23.5 $ — $ — $ — $ 23.5 Risk Management Assets Risk Management Commodity Contracts (c) (g) — 84.6 40.5 (85.6 ) 39.5 Total Assets $ 23.5 $ 84.6 $ 40.5 $ (85.6 ) $ 63.0 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 84.0 $ 2.8 $ (84.9 ) $ 1.9 December 31, 2018 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 25.6 $ — $ — $ — $ 25.6 Risk Management Assets Risk Management Commodity Contracts (c) (g) 0.1 59.1 58.3 (59.4 ) 58.1 Total Assets $ 25.7 $ 59.1 $ 58.3 $ (59.4 ) $ 83.7 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ 0.2 $ 58.4 $ 0.5 $ (58.5 ) $ 0.6 I&M Assets and Liabilities Measured at Fair Value on a Recurring Basis December 31, 2019 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ 59.5 $ 8.0 $ (57.6 ) $ 9.9 Spent Nuclear Fuel and Decommissioning Trusts Cash and Cash Equivalents (e) 6.7 — — 8.6 15.3 Fixed Income Securities: United States Government — 1,112.5 — — 1,112.5 Corporate Debt — 72.4 — — 72.4 State and Local Government — 7.6 — — 7.6 Subtotal Fixed Income Securities — 1,192.5 — — 1,192.5 Equity Securities - Domestic (b) 1,767.9 — — — 1,767.9 Total Spent Nuclear Fuel and Decommissioning Trusts 1,774.6 1,192.5 — 8.6 2,975.7 Total Assets $ 1,774.6 $ 1,252.0 $ 8.0 $ (49.0 ) $ 2,985.6 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 53.4 $ 2.2 $ (55.1 ) $ 0.5 December 31, 2018 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ 42.1 $ 10.3 $ (43.2 ) $ 9.2 Spent Nuclear Fuel and Decommissioning Trusts Cash and Cash Equivalents (e) 12.3 — — 10.2 22.5 Fixed Income Securities: United States Government — 996.1 — — 996.1 Corporate Debt — 52.4 — — 52.4 State and Local Government — 8.6 — — 8.6 Subtotal Fixed Income Securities — 1,057.1 — — 1,057.1 Equity Securities - Domestic (b) 1,395.3 — — — 1,395.3 Total Spent Nuclear Fuel and Decommissioning Trusts 1,407.6 1,057.1 — 10.2 2,474.9 Total Assets $ 1,407.6 $ 1,099.2 $ 10.3 $ (33.0 ) $ 2,484.1 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ 0.1 $ 41.2 $ 1.4 $ (42.3 ) $ 0.4 OPCo Assets and Liabilities Measured at Fair Value on a Recurring Basis December 31, 2019 Level 1 Level 2 Level 3 Other Total Liabilities: (in millions) Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ — $ 103.6 $ — $ 103.6 December 31, 2018 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 27.6 $ — $ — $ — $ 27.6 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 0.8 $ 99.4 $ (0.6 ) $ 99.6 PSO Assets and Liabilities Measured at Fair Value on a Recurring Basis December 31, 2019 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ — $ 16.3 $ (0.5 ) $ 15.8 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ — $ 0.5 $ (0.5 ) $ — December 31, 2018 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ — $ 10.8 $ (0.4 ) $ 10.4 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 0.3 $ 1.3 $ (0.6 ) $ 1.0 SWEPCo Assets and Liabilities Measured at Fair Value on a Recurring Basis December 31, 2019 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ — $ 6.5 $ (0.1 ) $ 6.4 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ — $ 5.1 $ (0.1 ) $ 5.0 December 31, 2018 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ — $ 5.6 $ (0.8 ) $ 4.8 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 0.4 $ 3.3 $ (1.1 ) $ 2.6 (a) Amounts in “Other” column primarily represent cash deposits in bank accounts with financial institutions or third-parties. Level 1 and Level 2 amounts primarily represent investments in money market funds. (b) Amounts represent publicly traded equity securities and equity-based mutual funds. (c) Amounts in “Other” column primarily represent counterparty netting of risk management and hedging contracts and associated cash collateral under the accounting guidance for “Derivatives and Hedging.” (d) The December 31, 2019 maturity of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), is as follows: Level 2 matures $(7) million in 2020 and $(3) million in periods 2021-2023; Level 3 matures $96 million in 2020, $36 million in periods 2021-2023, $25 million in periods 2024-2025 and $(12) million in periods 2026-2032. Risk management commodity contracts are substantially comprised of power contracts. (e) Amounts in “Other” column primarily represent accrued interest receivables from financial institutions. Level 1 amounts primarily represent investments in money market funds. (f) The December 31, 2018 maturity of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), is as follows: Level 2 matures $(4) million in 2019, $1 million in periods 2020-2022, $1 million in periods 2023-2024 and $1 million in periods 2025-2032; Level 3 matures $108 million in 2019, $37 million in periods 2020-2022, $23 million in periods 2023-2024 and $(12) million in periods 2025-2032. Risk management commodity contracts are substantially comprised of power contracts. (g) Substantially comprised of power contracts for the Registrant Subsidiaries. The following tables set forth a reconciliation of changes in the fair value of net trading derivatives classified as Level 3 in the fair value hierarchy: Year Ended December 31, 2019 AEP APCo I&M OPCo PSO SWEPCo (in millions) Balance as of December 31, 2018 $ 131.2 $ 57.8 $ 8.9 $ (99.4 ) $ 9.5 $ 2.3 Realized Gain (Loss) Included in Net Income (or Changes in Net Assets) (a) (b) 15.8 (13.9 ) 4.7 (0.9 ) 13.5 6.0 Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date (a) (0.1 ) — — — — — Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income (c) (15.1 ) — — — — — Settlements (117.6 ) (42.5 ) (13.0 ) 6.6 (23.0 ) (9.6 ) Transfers into Level 3 (d) (e) (0.6 ) (0.5 ) (0.3 ) — — — Transfers out of Level 3 (e) 35.6 (0.7 ) (0.4 ) — — — Changes in Fair Value Allocated to Regulated Jurisdictions (f) 60.7 37.5 5.9 (9.9 ) 15.8 2.7 Balance as of December 31, 2019 $ 109.9 $ 37.7 $ 5.8 $ (103.6 ) $ 15.8 $ 1.4 Year Ended December 31, 2018 AEP APCo I&M OPCo PSO SWEPCo (in millions) Balance as of December 31, 2017 $ 40.3 $ 24.7 $ 7.6 $ (132.4 ) $ 6.2 $ 5.9 Realized Gain (Loss) Included in Net Income (or Changes in Net Assets) (a) (b) 148.9 104.1 14.2 1.8 18.1 (4.8 ) Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date (a) 9.8 — — — — — Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income (c) 15.7 — — — — — Settlements (214.0 ) (127.9 ) (21.3 ) 4.6 (24.3 ) (2.1 ) Transfers into Level 3 (d) (e) 15.8 — — — — — Transfers out of Level 3 (e) (1.6 ) — (0.3 ) — — — Changes in Fair Value Allocated to Regulated Jurisdictions (f) 116.3 56.9 8.7 26.6 9.5 3.3 Balance as of December 31, 2018 $ 131.2 $ 57.8 $ 8.9 $ (99.4 ) $ 9.5 $ 2.3 Year Ended December 31, 2017 AEP APCo I&M OPCo PSO SWEPCo (in millions) Balance as of December 31, 2016 $ 2.5 $ 1.4 $ 2.8 $ (119.0 ) $ 0.7 $ 0.7 Realized Gain (Loss) Included in Net Income (or Changes in Net Assets) (a) (b) 37.3 17.2 4.0 (1.4 ) 3.1 6.0 Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date (a) 33.6 — — — — — Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income (c) (18.8 ) — — — — — Settlements (50.6 ) (18.9 ) (7.1 ) 7.4 (3.8 ) (6.8 ) Transfers into Level 3 (d) (e) 16.2 — — — — — Transfers out of Level 3 (e) (10.1 ) — — — — — Changes in Fair Value Allocated to Regulated Jurisdictions (f) 30.2 25.0 7.9 (19.4 ) 6.2 6.0 Balance as of December 31, 2017 $ 40.3 $ 24.7 $ 7.6 $ (132.4 ) $ 6.2 $ 5.9 (a) Included in revenues on the statements of income. (b) Represents the change in fair value between the beginning of the reporting period and the settlement of the risk management commodity contract. (c) Included in cash flow hedges on the statements of comprehensive income. (d) Represents existing assets or liabilities that were previously categorized as Level 2. (e) Transfers are recognized based on their value at the beginning of the reporting period that the transfer occurred. (f) Relates to the net gains (losses) of those contracts that are not reflected on the statements of income. These net gains (losses) are recorded as regulatory assets/liabilities or accounts payable. The following tables quantify the significant unobservable inputs used in developing the fair value of Level 3 positions: Significant Unobservable Inputs December 31, 2019 AEP Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input Low High Average (c) (in millions) Energy Contracts $ 296.7 $ 249.3 Discounted Cash Flow Forward Market Price (a) $ (0.05 ) $ 177.30 $ 31.31 Natural Gas Contracts — 4.9 Discounted Cash Flow Forward Market Price (b) 1.89 2.51 2.19 FTRs 75.7 8.3 Discounted Cash Flow Forward Market Price (a) (8.52 ) 9.34 0.42 Total $ 372.4 $ 262.5 December 31, 2018 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input Low High Average (c) (in millions) Energy Contracts $ 257.1 $ 212.5 Discounted Cash Flow Forward Market Price (a) $ (0.05 ) $ 176.57 $ 33.07 Natural Gas Contracts — 2.5 Discounted Cash Flow Forward Market Price (b) 2.18 3.54 2.47 FTRs 96.5 7.4 Discounted Cash Flow Forward Market Price (a) (11.68 ) 17.79 1.09 Total $ 353.6 $ 222.4 APCo Significant Unobservable Inputs December 31, 2019 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ 5.7 $ 2.6 Discounted Cash Flow Forward Market Price $ 12.70 $ 41.20 $ 25.92 FTRs 34.8 0.2 Discounted Cash Flow Forward Market Price (0.14 ) 7.08 1.70 Total $ 40.5 $ 2.8 December 31, 2018 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ 2.4 $ 0.5 Discounted Cash Flow Forward Market Price $ 16.82 $ 62.65 $ 37.00 FTRs 55.9 — Discounted Cash Flow Forward Market Price 0.10 15.16 3.27 Total $ 58.3 $ 0.5 I&M Significant Unobservable Inputs December 31, 2019 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ 3.4 $ 1.5 Discounted Cash Flow Forward Market Price $ 12.70 $ 41.20 $ 25.92 FTRs 4.6 0.7 Discounted Cash Flow Forward Market Price (0.75 ) 4.07 0.74 Total $ 8.0 $ 2.2 December 31, 2018 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ 1.4 $ 0.9 Discounted Cash Flow Forward Market Price $ 16.82 $ 62.65 $ 37.00 FTRs 8.9 0.5 Discounted Cash Flow Forward Market Price (2.11 ) 6.21 1.06 Total $ 10.3 $ 1.4 OPCo Significant Unobservable Inputs December 31, 2019 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ — $ 103.6 Discounted Cash Flow Forward Market Price $ 29.23 $ 61.43 $ 42.46 December 31, 2018 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ — $ 99.4 Discounted Cash Flow Forward Market Price $ 26.29 $ 62.74 $ 42.50 PSO Significant Unobservable Inputs December 31, 2019 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) FTRs $ 16.3 $ 0.5 Discounted Cash Flow Forward Market Price $ (8.52 ) $ 0.85 $ (2.31 ) December 31, 2018 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) FTRs $ 10.8 $ 1.3 Discounted Cash Flow Forward Market Price $ (11.68 ) $ 10.30 $ (1.40 ) SWEPCo Significant Unobservable Inputs December 31, 2019 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input Low High Average (c) (in millions) Natural Gas Contracts $ — $ 4.9 Discounted Cash Flow Forward Market Price (b) $ 1.89 $ 2.51 $ 2.18 FTRs 6.5 0.2 Discounted Cash Flow Forward Market Price (a) (8.52 ) 0.85 (2.31 ) Total $ 6.5 $ 5.1 December 31, 2018 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input Low High Average (c) (in millions) Natural Gas Contracts $ — $ 2.5 Discounted Cash Flow Forward Market Price (b) $ 2.18 $ 3.54 $ 2.47 FTRs 5.6 0.8 Discounted Cash Flow Forward Market Price (a) (11.68 ) 10.30 (1.40 ) Total $ 5.6 $ 3.3 (a) Represents market prices in dollars per MWh. (b) Represents market prices in dollars per MMBtu. (c) The weighted average is the product of the forward market price of the underlying commodity and volume weighted by term. The following table provides the measurement uncertainty of fair value measurements to increases (decreases) in significant unobservable inputs related to Energy Contracts, Natural Gas Contracts and FTRs for the Registrants as of December 31, 2019 and 2018 : Uncertainty of Fair Value Measurements Significant Unobservable Input Position Change in Input Impact on Fair Value Measurement Forward Market Price Buy Increase (Decrease) Higher (Lower) Forward Market Price Sell Increase (Decrease) Lower (Higher)

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Taxes	INCOME TAXES The disclosures in this note apply to all Registrants unless indicated otherwise. Income Tax Expense (Benefit) The details of the Registrants’ Income Tax Expense (Benefit) as reported are as follows: Year Ended December 31, 2019 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Federal: Current $ (7.4 ) $ (31.8 ) $ 23.7 $ 36.7 $ 48.1 $ (10.0 ) $ 25.5 $ 6.9 Deferred (77.1 ) (23.5 ) 71.7 (125.6 ) (53.5 ) 40.6 (23.6 ) (8.6 ) Deferred Investment Tax Credits 5.5 (1.2 ) — (0.5 ) (3.6 ) — (2.4 ) (1.4 ) Total Federal (79.0 ) (56.5 ) 95.4 (89.4 ) (9.0 ) 30.6 (0.5 ) (3.1 ) State and Local: Current 4.4 2.9 2.4 12.0 (2.4 ) 1.1 0.2 0.8 Deferred 59.3 — 19.6 (0.6 ) 0.8 3.2 5.4 (2.4 ) Deferred Investment Tax Credits 2.4 — — — — — 2.4 — Total State and Local 66.1 2.9 22.0 11.4 (1.6 ) 4.3 8.0 (1.6 ) Income Tax Expense (Benefit) $ (12.9 ) $ (53.6 ) $ 117.4 $ (78.0 ) $ (10.6 ) $ 34.9 $ 7.5 $ (4.7 ) Year Ended December 31, 2018 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Federal: Current $ (31.7 ) $ 37.0 $ (14.2 ) $ (31.9 ) $ 60.9 $ 55.6 $ 35.6 $ 18.3 Deferred 112.8 (16.4 ) 82.3 (24.6 ) (44.1 ) (36.9 ) (34.7 ) (0.5 ) Deferred Investment Tax Credits 9.2 (1.5 ) — 0.1 (4.7 ) — (2.0 ) (1.4 ) Total Federal 90.3 19.1 68.1 (56.4 ) 12.1 18.7 (1.1 ) 16.4 State and Local: Current 30.8 1.8 (0.6 ) 3.7 15.8 4.6 (0.2 ) 2.3 Deferred (8.5 ) (0.1 ) 16.6 7.8 1.2 0.7 3.6 1.7 Deferred Investment Tax Credits 2.7 — — — — — 2.7 — Total State and Local 25.0 1.7 16.0 11.5 17.0 5.3 6.1 4.0 Income Tax Expense (Benefit) $ 115.3 $ 20.8 $ 84.1 $ (44.9 ) $ 29.1 $ 24.0 $ 5.0 $ 20.4 Year Ended December 31, 2017 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Federal: Current $ (4.0 ) $ (85.7 ) $ (130.4 ) $ 15.3 $ (106.5 ) $ 11.2 $ (77.1 ) $ (30.1 ) Deferred 856.6 63.3 254.8 166.9 202.1 141.3 122.7 84.8 Deferred Investment Tax Credits 48.6 (1.6 ) — (0.1 ) (4.7 ) — (1.6 ) (1.4 ) Total Federal 901.2 (24.0 ) 124.4 182.1 90.9 152.5 44.0 53.3 State and Local: Current 16.0 0.6 1.1 (1.4 ) (8.1 ) 0.2 (0.2 ) (0.9 ) Deferred 44.9 — 16.7 4.6 (1.4 ) 6.6 2.0 (4.3 ) Deferred Investment Tax Credits 7.6 — — — — — 4.3 — Total State and Local 68.5 0.6 17.8 3.2 (9.5 ) 6.8 6.1 (5.2 ) Income Tax Expense (Benefit) $ 969.7 $ (23.4 ) $ 142.2 $ 185.3 $ 81.4 $ 159.3 $ 50.1 $ 48.1 The following are reconciliations for the Registrants between the federal income taxes computed by multiplying pretax income by the federal statutory tax rate and the income taxes reported: AEP Years Ended December 31, 2019 2018 2017 (in millions) Net Income $ 1,919.8 $ 1,931.3 $ 1,928.9 Less: Equity Earnings – Dolet Hills (3.0 ) (2.7 ) — Income Tax Expense (Benefit) (12.9 ) 115.3 969.7 Pretax Income $ 1,903.9 $ 2,043.9 $ 2,898.6 Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively) $ 399.8 $ 429.2 $ 1,014.5 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 23.1 24.4 60.2 Investment Tax Credit Amortization (13.0 ) (20.2 ) (18.8 ) Production Tax Credits (59.0 ) (10.3 ) — State and Local Income Taxes, Net 52.2 19.7 54.7 Removal Costs (20.7 ) (19.8 ) (32.7 ) AFUDC (37.1 ) (29.4 ) (37.4 ) Valuation Allowance — — (1.8 ) Tax Reform Adjustments — (10.9 ) (26.7 ) Tax Adjustments — — (35.8 ) Tax Reform Excess ADIT Reversal (353.2 ) (257.2 ) — Other (5.0 ) (10.2 ) (6.5 ) Income Tax Expense (Benefit) $ (12.9 ) $ 115.3 $ 969.7 Effective Income Tax Rate (0.7 ) % 5.6 % 33.5 % AEP Texas Years Ended December 31, 2019 2018 2017 (in millions) Net Income $ 178.3 $ 211.3 $ 310.5 Income Tax Expense (Benefit) (53.6 ) 20.8 (23.4 ) Pretax Income $ 124.7 $ 232.1 $ 287.1 Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively) $ 26.2 $ 48.7 $ 100.5 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 1.0 1.4 (0.5 ) Investment Tax Credit Amortization (1.2 ) (2.3 ) (1.5 ) State and Local Income Taxes, Net 2.3 1.3 0.4 AFUDC (3.2 ) (4.2 ) (3.9 ) Parent Company Loss Benefit (4.6 ) (3.1 ) — Tax Reform Adjustments — (11.0 ) (117.4 ) Tax Adjustments — — (4.2 ) Tax Reform Excess ADIT Reversal (73.4 ) (11.8 ) — Other (0.7 ) 1.8 3.2 Income Tax Expense (Benefit) $ (53.6 ) $ 20.8 $ (23.4 ) Effective Income Tax Rate (43.0 ) % 9.0 % (8.2 ) % AEPTCo Years Ended December 31, 2019 2018 2017 (in millions) Net Income $ 439.7 $ 315.9 $ 270.7 Income Tax Expense 117.4 84.1 142.2 Pretax Income $ 557.1 $ 400.0 $ 412.9 Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively) $ 117.0 $ 84.0 $ 144.5 Increase (Decrease) in Income Taxes Resulting from the Following Items: AFUDC (17.7 ) (14.1 ) (17.0 ) State and Local Income Taxes, Net 17.4 12.6 13.1 Tax Reform Adjustments — — 0.6 Other 0.7 1.6 1.0 Income Tax Expense $ 117.4 $ 84.1 $ 142.2 Effective Income Tax Rate 21.1 % 21.0 % 34.4 % APCo Years Ended December 31, 2019 2018 2017 (in millions) Net Income $ 306.3 $ 367.8 $ 331.3 Income Tax Expense (Benefit) (78.0 ) (44.9 ) 185.3 Pretax Income $ 228.3 $ 322.9 $ 516.6 Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively) $ 47.9 $ 67.8 $ 180.8 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 11.7 8.5 18.0 State and Local Income Taxes, Net 9.0 9.1 3.5 Removal Costs (6.1 ) (9.6 ) (12.4 ) AFUDC (5.2 ) (4.3 ) (5.0 ) Parent Company Loss Benefit (3.8 ) (3.4 ) (0.2 ) Tax Reform Adjustments — 0.1 4.3 Tax Reform Excess ADIT Reversal (130.4 ) (108.5 ) — Other (1.1 ) (4.6 ) (3.7 ) Income Tax Expense (Benefit) $ (78.0 ) $ (44.9 ) $ 185.3 Effective Income Tax Rate (34.2 ) % (13.9 ) % 35.9 % I&M Years Ended December 31, 2019 2018 2017 (in millions) Net Income $ 269.4 $ 261.3 $ 186.7 Income Tax Expense (Benefit) (10.6 ) 29.1 81.4 Pretax Income $ 258.8 $ 290.4 $ 268.1 Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively) $ 54.3 $ 61.0 $ 93.8 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 6.3 (0.7 ) 11.4 Investment Tax Credit Amortization (3.6 ) (4.7 ) (4.7 ) State and Local Income Taxes, Net (1.2 ) 13.4 (1.0 ) Removal Costs (11.5 ) (8.0 ) (13.3 ) AFUDC (4.1 ) (2.5 ) (5.6 ) Parent Company Loss Benefit (4.8 ) (2.3 ) — Tax Adjustments — — 2.7 Tax Reform Adjustments — — (2.9 ) Tax Reform Excess ADIT Reversal (42.5 ) (25.8 ) — Other (3.5 ) (1.3 ) 1.0 Income Tax Expense (Benefit) $ (10.6 ) $ 29.1 $ 81.4 Effective Income Tax Rate (4.1 ) % 10.0 % 30.4 % OPCo Years Ended December 31, 2019 2018 2017 (in millions) Net Income $ 297.1 $ 325.5 $ 323.9 Income Tax Expense 34.9 24.0 159.3 Pretax Income $ 332.0 $ 349.5 $ 483.2 Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively) $ 69.7 $ 73.4 $ 169.1 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation (1.7 ) 2.6 7.6 State and Local Income Taxes, Net 3.4 4.2 4.4 AFUDC (3.8 ) (2.1 ) (2.2 ) Tax Reform Adjustments — — (14.4 ) Tax Reform Excess ADIT Reversal (27.3 ) (51.0 ) — Parent Company Loss Benefit (4.9 ) (5.5 ) (0.2 ) Other (0.5 ) 2.4 (5.0 ) Income Tax Expense $ 34.9 $ 24.0 $ 159.3 Effective Income Tax Rate 10.5 % 6.9 % 33.0 % PSO Years Ended December 31, 2019 2018 2017 (in millions) Net Income $ 137.6 $ 83.2 $ 72.0 Income Tax Expense 7.5 5.0 50.1 Pretax Income $ 145.1 $ 88.2 $ 122.1 Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively) $ 30.5 $ 18.5 $ 42.7 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 0.5 1.0 0.3 Investment Tax Credit Amortization (0.5 ) (1.7 ) (1.6 ) Parent Company Loss Benefit (2.5 ) (1.4 ) — State and Local Income Taxes, Net 6.3 4.8 4.0 Tax Reform Adjustments — — 2.8 Tax Reform Excess ADIT Reversal (24.5 ) (15.5 ) — Other (2.3 ) (0.7 ) 1.9 Income Tax Expense $ 7.5 $ 5.0 $ 50.1 Effective Income Tax Rate 5.2 % 5.7 % 41.0 % SWEPCo Years Ended December 31, 2019 2018 2017 (in millions) Net Income $ 162.2 $ 152.2 $ 137.5 Less: Equity Earnings – Dolet Hills (3.0 ) (2.7 ) — Income Tax Expense (Benefit) (4.7 ) 20.4 48.1 Pretax Income $ 154.5 $ 169.9 $ 185.6 Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively) $ 32.4 $ 35.7 $ 65.0 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 1.9 3.4 1.9 Depletion (3.6 ) (3.2 ) (5.7 ) State and Local Income Taxes, Net (1.3 ) 3.2 (2.3 ) AFUDC (1.4 ) (1.3 ) (0.9 ) Tax Adjustments — — (9.9 ) Tax Reform Adjustments — — (0.4 ) Tax Reform Excess ADIT Reversal (29.9 ) (16.0 ) — Other (2.8 ) (1.4 ) 0.4 Income Tax Expense (Benefit) $ (4.7 ) $ 20.4 $ 48.1 Effective Income Tax Rate (3.0 ) % 12.0 % 25.9 % Net Deferred Tax Liability The following tables show elements of the net deferred tax liability and significant temporary differences for each Registrant: AEP December 31, 2019 2018 (in millions) Deferred Tax Assets $ 3,246.1 $ 2,750.8 Deferred Tax Liabilities (10,834.3 ) (9,837.3 ) Net Deferred Tax Liabilities $ (7,588.2 ) $ (7,086.5 ) Property Related Temporary Differences $ (6,602.9 ) $ (6,224.8 ) Amounts Due to Customers for Future Income Taxes 1,173.5 1,329.7 Deferred State Income Taxes (1,112.4 ) (1,072.5 ) Securitized Assets (178.7 ) (186.6 ) Regulatory Assets (371.1 ) (454.1 ) Accrued Nuclear Decommissioning (557.4 ) (453.7 ) Net Operating Loss Carryforward 77.6 78.3 Tax Credit Carryforward 247.2 113.7 Operating Lease Liability 182.6 — Investment in Partnership (446.6 ) (300.5 ) All Other, Net — 84.0 Net Deferred Tax Liabilities $ (7,588.2 ) $ (7,086.5 ) AEP Texas December 31, 2019 2018 (in millions) Deferred Tax Assets $ 220.0 $ 208.1 Deferred Tax Liabilities (1,185.4 ) (1,121.2 ) Net Deferred Tax Liabilities $ (965.4 ) $ (913.1 ) Property Related Temporary Differences $ (973.5 ) $ (836.3 ) Amounts Due to Customers for Future Income Taxes 126.7 141.2 Deferred State Income Taxes (27.5 ) (27.7 ) Regulatory Assets (51.2 ) (53.9 ) Securitized Transition Assets (124.3 ) (134.7 ) Deferred Revenues 19.9 4.6 Operating Lease Liability 17.2 — All Other, Net 47.3 (6.3 ) Net Deferred Tax Liabilities $ (965.4 ) $ (913.1 ) AEPTCo December 31, 2019 2018 (in millions) Deferred Tax Assets $ 162.9 $ 142.9 Deferred Tax Liabilities (980.7 ) (847.3 ) Net Deferred Tax Liabilities $ (817.8 ) $ (704.4 ) Property Related Temporary Differences $ (847.1 ) $ (755.0 ) Amounts Due to Customers for Future Income Taxes 119.9 121.3 Deferred State Income Taxes (86.1 ) (71.6 ) Net Operating Loss Carryforward 12.3 13.4 All Other, Net (16.8 ) (12.5 ) Net Deferred Tax Liabilities $ (817.8 ) $ (704.4 ) APCo December 31, 2019 2018 (in millions) Deferred Tax Assets $ 486.2 $ 475.2 Deferred Tax Liabilities (2,167.0 ) (2,101.0 ) Net Deferred Tax Liabilities $ (1,680.8 ) $ (1,625.8 ) Property Related Temporary Differences $ (1,420.0 ) $ (1,393.6 ) Amounts Due to Customers for Future Income Taxes 222.8 268.0 Deferred State Income Taxes (320.9 ) (324.1 ) Regulatory Assets (71.0 ) (73.8 ) Securitized Assets (49.3 ) (54.3 ) Operating Lease Liability 16.5 — All Other, Net (58.9 ) (48.0 ) Net Deferred Tax Liabilities $ (1,680.8 ) $ (1,625.8 ) I&M December 31, 2019 2018 (in millions) Deferred Tax Assets $ 970.5 $ 771.6 Deferred Tax Liabilities (1,950.2 ) (1,719.6 ) Net Deferred Tax Liabilities $ (979.7 ) $ (948.0 ) Property Related Temporary Differences $ (430.7 ) $ (445.0 ) Amounts Due to Customers for Future Income Taxes 169.6 186.2 Deferred State Income Taxes (194.4 ) (183.9 ) Accrued Nuclear Decommissioning (557.4 ) (453.7 ) Regulatory Assets (26.9 ) (31.9 ) Net Operating Loss Carryforward — 0.2 Operating Lease Liability 61.9 — All Other, Net (1.8 ) (19.9 ) Net Deferred Tax Liabilities $ (979.7 ) $ (948.0 ) OPCo December 31, 2019 2018 (in millions) Deferred Tax Assets $ 202.3 $ 209.0 Deferred Tax Liabilities (1,051.6 ) (972.3 ) Net Deferred Tax Liabilities $ (849.3 ) $ (763.3 ) Property Related Temporary Differences $ (890.8 ) $ (826.9 ) Amounts Due to Customers for Future Income Taxes 130.2 137.0 Deferred State Income Taxes (35.5 ) (32.9 ) Regulatory Assets (48.0 ) (55.0 ) Operating Lease Liability 18.3 — All Other, Net (23.5 ) 14.5 Net Deferred Tax Liabilities $ (849.3 ) $ (763.3 ) PSO December 31, 2019 2018 (in millions) Deferred Tax Assets $ 257.4 $ 229.6 Deferred Tax Liabilities (885.7 ) (837.4 ) Net Deferred Tax Liabilities $ (628.3 ) $ (607.8 ) Property Related Temporary Differences $ (627.6 ) $ (609.4 ) Amounts Due to Customers for Future Income Taxes 127.2 138.9 Deferred State Income Taxes (100.4 ) (135.6 ) Regulatory Assets (44.6 ) (32.3 ) Net Operating Loss Carryforward 10.2 16.4 All Other, Net 6.9 14.2 Net Deferred Tax Liabilities $ (628.3 ) $ (607.8 ) SWEPCo December 31, 2019 2018 (in millions) Deferred Tax Assets $ 359.6 $ 317.4 Deferred Tax Liabilities (1,300.5 ) (1,220.2 ) Net Deferred Tax Liabilities $ (940.9 ) $ (902.8 ) Property Related Temporary Differences $ (947.6 ) $ (913.3 ) Amounts Due to Customers for Future Income Taxes 169.8 183.4 Deferred State Income Taxes (200.3 ) (193.6 ) Regulatory Assets (30.2 ) (30.8 ) Net Operating Loss Carryforward 38.2 36.2 All Other, Net 29.2 15.3 Net Deferred Tax Liabilities $ (940.9 ) $ (902.8 ) AEP System Tax Allocation Agreement AEP and subsidiaries join in the filing of a consolidated federal income tax return. The allocation of the AEP System’s current consolidated federal income tax to the AEP System companies allocates the benefit of current tax losses (“Parent Company Loss Benefit”) to the AEP System companies giving rise to such losses in determining their current tax expense. The consolidated net operating loss of the AEP System is allocated to each company in the consolidated group with taxable losses. The tax benefit of the Parent is allocated to its subsidiaries with taxable income. With the exception of the allocation of the consolidated AEP System net operating loss, the loss of the Parent and tax credits, the method of allocation reflects a separate return result for each company in the consolidated group. Federal and State Income Tax Audit Status AEP and subsidiaries are no longer subject to U.S. federal examination by the IRS for all years through 2015. During the third quarter of 2019, AEP and subsidiaries elected to amend the 2014 and 2015 federal returns and as such the IRS may examine only the amended items on the 2014 and 2015 federal returns. Net Income Tax Operating Loss Carryforward As of December 31, 2019, AEP has no federal net income tax operating loss carryforward. AEP, AEPTCo, I&M, PSO and SWEPCo have state net income tax operating loss carryforwards as indicated in the table below: State Net Income Tax Operating Loss Years of Company State/Municipality Carryforward Expiration (in millions) AEP Arkansas $ 102.5 2020 - 2024 AEP Kentucky 144.9 2030 - 2037 AEP Louisiana 541.0 2025 - 2039 AEP Oklahoma 544.1 2034 - 2037 AEP Tennessee 29.0 2028 - 2034 AEP Virginia 22.6 2030 - 2037 AEP West Virginia 16.1 2029 - 2037 AEP Ohio Municipal 414.1 2020 - 2024 AEPTCo Oklahoma 269.4 2034 - 2037 AEPTCo Ohio Municipal 37.3 2020 - 2023 I&M West Virginia 2.0 2031 - 2037 PSO Oklahoma 240.5 2034 - 2037 SWEPCo Arkansas 101.7 2021 - 2024 SWEPCo Louisiana 528.1 2032 - 2037 As of December 31, 2019, AEP has recorded a valuation allowance of $6 million , against certain state and municipal net income tax operating loss carryforwards since future taxable income is not expected to be sufficient to realize the remaining state net income tax operating loss tax benefits before the carryforward expires. Management anticipates future taxable income will be sufficient to realize the remaining state net income tax operating loss tax benefits before the carryforward expires for each state. Tax Credit Carryforward Federal and state net income tax operating losses sustained in 2017, 2012 and 2011 resulted in unused federal and state income tax credits. As of December 31, 2019, the Registrants have federal tax credit carryforwards and AEP and PSO have state tax credit carryforwards as indicated in the table below. If these credits are not utilized, federal general business tax credits will expire in the years 2031 through 2039. Federal Tax State Tax Credit Credit Total Federal Carryforward Total State Carryforward Tax Credit Subject to Tax Credit Subject to Company Carryforward Expiration Carryforward Expiration (in millions) AEP $ 247.2 $ 239.6 $ 36.7 $ — AEP Texas 1.4 1.3 — — AEPTCo 0.2 0.1 — — APCo 4.9 2.3 — — I&M 13.9 13.7 — — OPCo 5.1 1.7 — — PSO 1.1 1.1 36.7 — SWEPCo 1.9 1.8 — — The Registrants anticipate future federal taxable income will be sufficient to realize the tax benefits of the federal tax credits before they expire unused. Valuation Allowance AEP assesses the available positive and negative evidence to estimate whether sufficient future taxable income of the appropriate tax character will be generated to realize the benefits of existing deferred tax assets. When the evaluation of the evidence indicates that AEP will not be able to realize the benefits of existing deferred tax assets, a valuation allowance is recorded to reduce existing deferred tax assets to the net realizable amount. Objective evidence evaluated includes whether AEP has a history of recognizing income of the character which can be offset by loss carryforwards. Other objective negative evidence evaluated is the impact recently enacted federal tax legislation will have on future taxable income and on AEP’s ability to benefit from the carryforward of charitable contribution deductions. Valuation allowance activity for the years ended December 31, 2019, 2018 and 2017 was immaterial. Uncertain Tax Positions The reconciliations of the beginning and ending amounts of unrecognized tax benefits are as follows: AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Balance as of January 1, 2019 $ 14.6 $ (0.8 ) $ — $ — $ 3.2 $ 6.9 $ — $ (0.8 ) Increase – Tax Positions Taken During a Prior Period 8.8 1.5 — — — 1.6 — 0.8 Decrease – Tax Positions Taken During a Prior Period (2.1 ) (0.7 ) — — (0.7 ) — — — Increase – Tax Positions Taken During the Current Year 2.8 — — — — — — — Decrease – Tax Positions Taken During the Current Year — — — — — — — — Decrease – Settlements with Taxing Authorities — — — — — — — — Decrease – Lapse of the Applicable Statute of Limitations — — — — — — — — Balance as of December 31, 2019 $ 24.1 $ — $ — $ — $ 2.5 $ 8.5 $ — $ — AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Balance as of January 1, 2018 $ 86.6 $ (0.8 ) $ — $ — $ 3.2 $ 6.9 $ — $ (0.8 ) Increase – Tax Positions Taken During a Prior Period 0.1 — — — — — — — Decrease – Tax Positions Taken During a Prior Period — — — — — — — — Increase – Tax Positions Taken During the Current Year — — — — — — — — Decrease – Tax Positions Taken During the Current Year — — — — — — — — Decrease – Settlements with Taxing Authorities (71.0 ) — — — — — — — Decrease – Lapse of the Applicable Statute of Limitations (1.1 ) — — — — — — — Balance as of December 31, 2018 $ 14.6 $ (0.8 ) $ — $ — $ 3.2 $ 6.9 $ — $ (0.8 ) AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Balance as of January 1, 2017 $ 98.8 $ 6.5 $ — $ — $ 3.8 $ 6.9 $ 0.1 $ 1.3 Increase – Tax Positions Taken During a Prior Period 4.5 2.0 — — 0.2 — 0.1 1.7 Decrease – Tax Positions Taken During a Prior Period (28.0 ) (12.3 ) — — (0.5 ) — (0.9 ) (5.4 ) Increase – Tax Positions Taken During the Current Year 3.4 — — — — — — — Decrease – Tax Positions Taken During the Current Year — — — — — — — — Decrease – Settlements with Taxing Authorities 7.9 3.0 — — (0.3 ) — 0.7 1.6 Decrease – Lapse of the Applicable Statute of Limitations — — — — — — — — Balance as of December 31, 2017 $ 86.6 $ (0.8 ) $ — $ — $ 3.2 $ 6.9 $ — $ (0.8 ) Management believes that there will be no significant net increase or decrease in unrecognized benefits within 12 months of the reporting date. The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate for each Registrant was as follows: Company 2019 2018 2017 (in millions) AEP $ 20.3 $ 11.6 $ 10.5 AEP Texas — (0.7 ) (0.5 ) AEPTCo — — — APCo — — — I&M 2.0 2.6 2.1 OPCo 6.7 5.4 4.5 PSO — — — SWEPCo — (0.6 ) (0.5 ) Federal Tax Reform and Legislation In December 2017, Tax Reform legislation was signed into law. Tax Reform included significant changes to the Internal Revenue Code of 1986, as amended, including lowering the corporate federal income tax rate from 35% to 21%. The IRS has issued new regulations that provide guidance regarding the additional first-year depreciation deduction under Section 168(k). The proposed regulations reflect changes as a result of Tax Reform and affect taxpayers with qualified depreciable property acquired and placed in-service after September 27, 2017. Generally, AEP’s regulated utilities will not be eligible for any bonus depreciation for property acquired and placed in-service after December 31, 2017 and AEP’s competitive businesses will be eligible for 100% expensing. During the fourth quarter of 2018, the IRS proposed new regulations that reflect changes as a result of Tax Reform concerning potential limitations on the deduction of business interest expense. These regulations require an allocation of net interest expense between regulated and competitive businesses within the consolidated tax return. This allocation is based upon net tax basis, and the proposed regulations provide a de minimis test under which all interest is deductible if less than 10% is allocable to the competitive businesses. Management continues to review and evaluate the proposed regulations and at this time expect to be able to deduct materially all business interest expense under this de minimis provision. State Tax Legislation In April 2018, the Kentucky legislature enacted House Bill (H.B.) 487. H.B. 487 adopts mandatory unitary combined reporting for state corporate income tax purposes applicable for taxable years beginning on or after January 1, 2019. H.B. 487 also adopts the 80% federal net operating loss (NOL) limitation under Internal Revenue Code Section 172(a) for NOLs generated after January 1, 2018 and the federal unlimited carryforward period for unused NOLs generated after January 1, 2018. In addition, H.B. 366 was also enacted in April 2018, which among other things, replaces the graduated corporate tax rate structure with a flat 5% tax rate for business income and adopts a single-sales factor apportionment formula for apportioning a corporation’s business income to Kentucky. In the second quarter of 2018, AEP recorded an $18 million benefit to Income Tax Expense as a result of remeasuring Kentucky deferred taxes under a unitary filing group. The enacted legislation did not materially impact AEPTCo’s, I&M’s or OPCo’s net income.

Leases

Leases	12 Months Ended
	Dec. 31, 2019
Leases	LEASES The disclosures in this note apply to all Registrants unless indicated otherwise. The Registrants lease property, plant and equipment including, but not limited to, fleet, information technology and real estate leases. These leases require payments of non-lease components, including related property taxes, operating and maintenance costs. As of the adoption date of ASU 2016-02, management elected not to separate non-lease components from associated lease components in accordance with the accounting guidance for “Leases.” Many of these leases have purchase or renewal options. Leases not renewed are often replaced by other leases. Options to renew or purchase a lease are included in the measurement of lease assets and liabilities if it is reasonably certain the Registrant will exercise the option. Lease obligations are measured using the discount rate implicit in the lease when that rate is readily determinable. AEP has visibility into the rate implicit in the lease when assets are leased from selected financial institutions under master leasing agreements. When the implicit rate is not readily determinable, the Registrants measure their lease obligation using their estimated secured incremental borrowing rate. Incremental borrowing rates are comprised of an underlying risk free rate and a secured credit spread relative to the lessee on a matched maturity basis. Operating lease rentals and finance lease amortization costs are generally charged to Other Operation and Maintenance expense in accordance with rate-making treatment for regulated operations. Effective in 2019, interest on finance lease liabilities is generally charged to Interest Expense. Finance lease interest for periods prior to 2019 were charged to Other Operation and Maintenance expense. Lease costs associated with capital projects are included in Property, Plant and Equipment on the balance sheets. For regulated operations with finance leases, a finance lease asset and offsetting liability are recorded at the present value of the remaining lease payments for each reporting period. Finance leases for nonregulated property are accounted for as if the assets were owned and financed. The components of rental costs were as follows: Year Ended December 31, 2019 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Operating Lease Cost $ 286.0 $ 16.5 $ 2.5 $ 19.5 $ 93.1 $ 18.0 $ 6.8 $ 8.0 Finance Lease Cost: Amortization of Right-of-Use Assets 70.8 5.1 0.1 6.7 5.7 3.5 3.1 11.0 Interest on Lease Liabilities 16.4 1.4 — 2.9 2.9 0.7 0.6 2.9 Total Lease Rental Costs (a) $ 373.2 $ 23.0 $ 2.6 $ 29.1 $ 101.7 $ 22.2 $ 10.5 $ 21.9 Year Ended December 31, 2018 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Operating Lease Cost $ 245.0 $ 13.6 $ 2.7 $ 18.2 $ 89.2 $ 10.7 $ 5.7 $ 6.5 Finance Lease Cost: Amortization of Right-of-Use Assets 62.4 4.8 0.1 7.0 6.6 3.9 3.2 11.2 Interest on Lease Liabilities 16.4 1.2 — 3.0 3.3 0.5 0.4 3.2 Total Lease Rental Costs $ 323.8 $ 19.6 $ 2.8 $ 28.2 $ 99.1 $ 15.1 $ 9.3 $ 20.9 Year Ended December 31, 2017 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Operating Lease Cost $ 231.3 $ 10.5 $ 1.7 $ 17.5 $ 88.4 $ 8.2 $ 4.4 $ 5.3 Finance Lease Cost: Amortization of Right-of-Use Assets 66.3 4.0 — 6.9 11.1 4.1 4.0 11.2 Interest on Lease Liabilities 16.7 0.8 — 3.7 3.2 0.5 0.6 3.6 Total Lease Rental Costs $ 314.3 $ 15.3 $ 1.7 $ 28.1 $ 102.7 $ 12.8 $ 9.0 $ 20.1 (a) Excludes variable and short-term lease costs, which were immaterial for the twelve months ended December 31, 2019 . Supplemental information related to leases are shown in the tables below: December 31, 2019 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo Weighted-Average Remaining Lease Term (years): Operating Leases 5.23 6.93 2.25 6.28 3.91 7.94 7.07 6.64 Finance Leases 5.85 6.69 0.25 6.12 6.55 6.49 6.23 5.16 Weighted-Average Discount Rate: Operating Leases 3.60 % 3.77 % 3.14 % 3.64 % 3.45 % 3.76 % 3.64 % 3.76 % Finance Leases 5.98 % 4.62 % 9.33 % 8.08 % 8.47 % 4.54 % 4.62 % 5.01 % Year Ended December 31,2019 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Cash paid for amounts included in the measurement of lease liabilities: Operating Cash Flows Used for Operating Leases $ 284.7 $ 15.3 $ 2.4 $ 19.0 $ 94.3 $ 18.0 $ 6.7 $ 7.9 Operating Cash Flows Used for Finance Leases 16.4 1.4 — 2.9 3.1 0.7 0.6 3.0 Financing Cash Flows Used for Finance Leases 70.7 5.1 — 6.7 5.7 3.5 3.1 11.0 Non-cash Acquisitions Under Operating Leases $ 125.0 $ 13.8 $ 0.6 $ 10.2 $ 18.7 $ 35.4 $ 8.2 $ 11.4 The following tables show property, plant and equipment under finance leases and noncurrent assets under operating leases and related obligations recorded on the balance sheets. Unless shown as a separate line on the balance sheets due to materiality, net operating lease assets are included in Deferred Charges and Other Noncurrent Assets, current finance lease obligations are included in Other Current Liabilities and long-term finance lease obligations are included in Deferred Credits and Other Noncurrent Liabilities on the balance sheets. Lease obligations are not recognized on the balance sheets for lease agreements with a lease term of less than twelve months. December 31, 2019 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Property, Plant and Equipment Under Finance Leases: Generation $ 131.6 $ — $ — $ 39.9 $ 28.8 $ — $ 0.6 $ 34.1 Other Property, Plant and Equipment 323.0 45.9 0.2 18.9 39.3 27.3 21.6 51.6 Total Property, Plant and Equipment 454.6 45.9 0.2 58.8 68.1 27.3 22.2 85.7 Accumulated Amortization 151.5 11.8 0.2 17.0 23.0 7.2 7.1 28.4 Net Property, Plant and Equipment Under Finance Leases $ 303.1 $ 34.1 $ — $ 41.8 $ 45.1 $ 20.1 $ 15.1 $ 57.3 Obligations Under Finance Leases: Noncurrent Liability $ 249.2 $ 28.2 $ — $ 35.0 $ 38.8 $ 16.2 $ 11.9 $ 47.1 Liability Due Within One Year 57.6 5.9 — 6.8 6.3 3.9 3.2 10.5 Total Obligations Under Finance Leases $ 306.8 $ 34.1 $ — $ 41.8 $ 45.1 $ 20.1 $ 15.1 $ 57.6 December 31, 2018 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Property, Plant and Equipment Under Finance Leases: Generation $ 131.3 $ — $ — $ 38.7 $ 27.0 $ — $ 2.6 $ 34.3 Other Property, Plant and Equipment 373.9 38.8 0.2 17.3 33.3 20.4 17.6 119.8 Total Property, Plant and Equipment 505.2 38.8 0.2 56.0 60.3 20.4 20.2 154.1 Accumulated Amortization 226.4 10.3 0.1 16.2 21.6 8.3 7.9 99.9 Net Property, Plant and Equipment Under Finance Leases $ 278.8 $ 28.5 $ 0.1 $ 39.8 $ 38.7 $ 12.1 $ 12.3 $ 54.2 Obligations Under Finance Leases: Noncurrent Liability $ 233.5 $ 24.0 $ — $ 33.7 $ 33.4 $ 9.2 $ 9.5 $ 50.6 Liability Due Within One Year 55.5 55.5 4.5 0.1 6.1 5.3 2.9 2.8 10.2 Total Obligations Under Finance Leases $ 289.0 $ 28.5 $ 0.1 $ 39.8 $ 38.7 $ 12.1 $ 12.3 $ 60.8 December 31, 2019 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Operating Lease Assets $ 957.4 $ 81.8 $ 3.8 $ 78.5 $ 294.9 $ 88.0 $ 36.8 $ 40.5 Obligations Under Operating Leases: Noncurrent Liability $ 734.6 $ 71.1 $ 1.9 $ 64.0 $ 211.6 $ 76.0 $ 31.0 $ 34.7 Liability Due Within One Year 234.1 12.0 2.1 15.2 87.3 12.5 5.8 6.5 Total Obligations Under Operating Leases $ 968.7 $ 83.1 $ 4.0 $ 79.2 $ 298.9 $ 88.5 $ 36.8 $ 41.2 Future minimum lease payments consisted of the following as of December 31, 2019 : Finance Leases AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) 2020 $ 72.7 $ 7.3 $ — $ 9.6 $ 9.4 $ 4.7 $ 3.8 $ 12.9 2021 64.9 6.7 — 8.9 8.7 4.3 3.2 11.9 2022 56.4 6.0 — 8.2 8.0 3.4 2.6 10.6 2023 49.6 5.4 — 7.7 7.5 2.8 2.3 9.8 2024 57.4 4.6 — 7.1 10.8 2.4 1.8 14.2 Later Years 64.4 9.8 — 9.8 16.4 5.7 3.8 6.8 Total Future Minimum Lease Payments 365.4 39.8 — 51.3 60.8 23.3 17.5 66.2 Less: Imputed Interest 58.6 5.7 — 9.5 15.7 3.2 2.4 8.6 Estimated Present Value of Future Minimum Lease Payments $ 306.8 $ 34.1 $ — $ 41.8 $ 45.1 $ 20.1 $ 15.1 $ 57.6 Operating Leases AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) 2020 $ 269.9 $ 16.0 $ 2.2 $ 18.3 $ 97.0 $ 16.2 $ 7.3 $ 8.6 2021 253.6 15.3 1.2 15.7 92.9 14.2 6.4 8.2 2022 245.6 14.2 0.6 14.7 92.8 13.5 6.0 7.6 2023 74.8 13.0 0.1 11.9 10.1 12.3 5.6 6.4 2024 62.0 11.4 — 9.0 8.6 10.7 4.8 5.0 Later Years 169.7 26.0 — 20.0 21.0 36.5 12.0 11.8 Total Future Minimum Lease Payments 1,075.6 95.9 4.1 89.6 322.4 103.4 42.1 47.6 Less: Imputed Interest 106.9 12.8 0.1 10.4 23.5 14.9 5.3 6.4 Estimated Present Value of Future Minimum Lease Payments $ 968.7 $ 83.1 $ 4.0 $ 79.2 $ 298.9 $ 88.5 $ 36.8 $ 41.2 Future minimum lease payments consisted of the following as of December 31, 2018 : Finance Leases AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) 2019 $ 70.8 $ 5.8 $ 0.1 $ 9.0 $ 8.2 $ 3.3 $ 3.4 $ 13.1 2020 60.2 5.3 — 8.0 7.2 2.7 2.6 11.5 2021 51.7 4.7 — 7.3 6.6 2.3 2.0 10.5 2022 43.8 4.2 — 6.8 6.1 1.7 1.6 9.4 2023 35.5 3.7 — 6.3 5.7 1.2 1.4 8.6 Later Years 90.2 10.1 — 13.3 21.7 2.8 3.3 18.7 Total Future Minimum Lease Payments 352.2 33.8 0.1 50.7 55.5 14.0 14.3 71.8 Less: Imputed Interest 63.2 5.3 — 10.9 16.8 1.9 2.0 11.0 Estimated Present Value of Future Minimum Lease Payments $ 289.0 $ 28.5 $ 0.1 $ 39.8 $ 38.7 $ 12.1 $ 12.3 $ 60.8 Operating Leases AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) 2019 $ 259.6 $ 15.1 $ 2.3 $ 17.6 $ 92.6 $ 14.5 $ 6.5 $ 7.4 2020 250.1 14.1 1.8 16.5 89.3 13.2 6.0 7.2 2021 232.7 13.2 1.0 13.9 84.8 10.9 5.0 6.7 2022 222.5 12.2 0.5 12.8 83.8 10.0 4.6 6.1 2023 58.3 10.8 0.1 9.9 6.5 8.8 4.1 5.0 Later Years 165.2 28.4 — 20.5 19.5 31.7 10.7 11.7 Total Future Minimum Lease Payments $ 1,188.4 $ 93.8 $ 5.7 $ 91.2 $ 376.5 $ 89.1 $ 36.9 $ 44.1 Master Lease Agreements (Applies to all Registrants except AEPTCo) The Registrants lease certain equipment under master lease agreements. Under the lease agreements, the lessor is guaranteed a residual value up to a stated percentage of the equipment cost at the end of the lease term. If the actual fair value of the leased equipment is below the guaranteed residual value at the end of the lease term, the Registrants are committed to pay the difference between the actual fair value and the residual value guarantee. Historically, at the end of the lease term the fair value has been in excess of the amount guaranteed. As of December 31, 2019 , the maximum potential loss by the Registrants for these lease agreements assuming the fair value of the equipment is zero at the end of the lease term was as follows: Company Maximum Potential Loss (in millions) AEP $ 47.3 AEP Texas 11.3 APCo 6.6 I&M 4.1 OPCo 7.3 PSO 4.2 SWEPCo 4.8 Rockport Lease (Applies to AEP and I&M) AEGCo and I&M entered into a sale-and-leaseback transaction in 1989 with Wilmington Trust Company (Owner Trustee), an unrelated, unconsolidated trustee for Rockport Plant, Unit 2 (the Plant). The Owner Trustee was capitalized with equity from six owner participants with no relationship to AEP or any of its subsidiaries and debt from a syndicate of banks and securities in a private placement to certain institutional investors. In the first quarter of 2019, in accordance with ASU 2016-02, the $37 million unamortized gain ( $15 million related to I&M) associated with the sale-and-leaseback of the Plant was recognized as an adjustment to equity. The adjustment to equity was then reclassified to regulatory liabilities in accordance with accounting guidance for “Regulated Operations” as AEGCo and I&M will continue to provide the benefit of the unamortized gain to customers in future periods. The Owner Trustee owns the Plant and leases equal portions to AEGCo and I&M. The lease is accounted for as an operating lease with the payment obligations included in the future minimum lease payments schedule earlier in this note. The lease term is for 33 years and at the end of the lease term, AEGCo and I&M have the option to renew the lease at a rate that approximates fair value. The option to renew was not included in the measurement of the lease obligation as of December 31, 2019 as the execution of the option was not reasonably certain. AEP, AEGCo and I&M have no ownership interest in the Owner Trustee and do not guarantee its debt. The future minimum lease payments for this sale-and-leaseback transaction as of December 31, 2019 were as follows: Future Minimum Lease Payments AEP (a) I&M (in millions) 2020 $ 147.8 $ 73.9 2021 147.8 73.9 2022 147.5 73.7 Total Future Minimum Lease Payments $ 443.1 $ 221.5 (a) AEP’s future minimum lease payments include equal shares from AEGCo and I&M. AEPRO Boat and Barge Leases (Applies to AEP) In 2015, AEP sold its commercial barge transportation subsidiary, AEPRO, to a nonaffiliated party. Certain boat and barge leases acquired by the nonaffiliated party are subject to an AEP guarantee in favor of the respective lessors, ensuring future payments under such leases with maturities up to 2027. As of December 31, 2019 , the maximum potential amount of future payments required under the guaranteed leases was $55 million . Under the terms of certain of the arrangements, upon the lessors exercising their rights after an event of default by the nonaffiliated party, AEP is entitled to enter into new lease arrangements as a lessee that would have substantially the same terms as the existing leases. Alternatively, for the arrangements with one of the lessors, upon an event of default by the nonaffiliated party and the lessor exercising its rights, payment to the lessor would allow AEP to step into the lessor’s rights as well as obtaining title to the assets. Under either situation, AEP would have the ability to utilize the assets in the normal course of barging operations. AEP would also have the right to sell the acquired assets for which it obtained title. As of December 31, 2019 , AEP’s boat and barge lease guarantee liability was $5 million , of which $2 million was recorded in Other Current Liabilities and $3 million was recorded in Deferred Credits and Other Noncurrent Liabilities on AEP’s balance sheet. In February 2020, the nonaffiliated party filed Chapter 11 bankruptcy. The party entered into a restructuring support agreement and has announced it expects to continue their operations as normal. Management has determined that it is reasonably possible that enforcement of AEP’s liability for future payments under these leases will be exercised within the next twelve months. In such an event, if AEP is unable to sell or incorporate any of the acquired assets into its fleet operations, it could reduce future net income and cash flows and impact financial condition. Lessor Activity The Registrants’ lessor activity was immaterial as of and for the twelve months ended December 31, 2019 .

Financing Activities

Financing Activities	12 Months Ended
	Dec. 31, 2019
Financing Activities	FINANCING ACTIVITIES The disclosures in this note apply to all Registrants, unless indicated otherwise. Common Stock (Applies to AEP) The following table is a reconciliation of common stock share activity: Shares of AEP Common Stock Issued Held in Treasury Balance, December 31, 2016 512,048,520 20,336,592 Issued 162,124 — Treasury Stock Reissued — (131,546 ) (a) Balance, December 31, 2017 512,210,644 20,205,046 Issued 1,239,392 — Treasury Stock Reissued — (886 ) (a) Balance, December 31, 2018 513,450,036 20,204,160 Issued 923,595 — Balance, December 31, 2019 514,373,631 20,204,160 (a) Reissued Treasury Stock used to fulfill share commitments related to AEP’s Share-based Compensation. See “Shared-based Compensation Plans” section of Note 15 for additional information. Long-term Debt The following table details long-term debt outstanding: Weighted-Average Interest Rate Ranges as of Outstanding as of Interest Rate as of December 31, December 31, Company Maturity December 31, 2019 2019 2018 2019 2018 AEP (in millions) Senior Unsecured Notes 2019-2050 4.29% 2.15%-8.13% 2.15%-8.13% $ 21,180.7 $ 18,903.3 Pollution Control Bonds (a) 2019-2038 (b) 2.75% 1.35%-5.38% 1.60%-6.30% 1,998.8 1,643.8 Notes Payable – Nonaffiliated (c) 2019-2032 3.27% 2.42%-6.37% 3.20%-6.37% 234.3 204.7 Securitization Bonds 2019-2029 (d) 3.23% 1.98%-5.31% 1.98%-5.31% 1,025.1 1,111.4 Spent Nuclear Fuel Obligation (e) 279.8 273.6 Junior Subordinated Notes (f) 2022 3.40% 3.40% 787.8 — Other Long-term Debt 2019-2059 3.03% 1.15%-13.718% 1.15%-13.718% 1,219.0 1,209.9 Total Long-term Debt Outstanding $ 26,725.5 $ 23,346.7 AEP Texas Senior Unsecured Notes 2019-2050 4.01% 2.40%-6.76% 2.40%-6.76% $ 3,090.9 $ 2,398.4 Pollution Control Bonds 2020-2030 3.63% 1.75%-4.55% 1.75%-6.30% 490.3 490.9 Securitization Bonds 2020-2029 (d) 3.25% 1.98%-5.31% 1.98%-5.31% 776.8 791.2 Other Long-term Debt 2019-2059 3.06% 3.05%-4.50% 3.94%-4.50% 200.4 200.8 Total Long-term Debt Outstanding $ 4,558.4 $ 3,881.3 AEPTCo Senior Unsecured Notes 2019-2049 3.86% 3.10%-5.52% 2.68%-5.52% $ 3,427.3 $ 2,823.0 Total Long-term Debt Outstanding $ 3,427.3 $ 2,823.0 APCo Senior Unsecured Notes 2021-2049 5.12% 3.30%-7.00% 3.30%-7.00% $ 3,442.7 $ 3,047.3 Pollution Control Bonds (a) 2019-2038 (b) 2.64% 1.67%-5.38% 1.70%-5.38% 546.1 616.0 Securitization Bonds 2023-2028 (d) 3.17% 2.008%-3.772% 2.008%-3.772% 248.3 272.3 Other Long-term Debt 2019-2026 3.14% 2.97%-13.718% 3.74%-13.718% 126.7 127.0 Total Long-term Debt Outstanding $ 4,363.8 $ 4,062.6 I&M Senior Unsecured Notes 2023-2048 4.38% 3.20%-6.05% 3.20%-6.05% $ 2,150.7 $ 2,149.0 Pollution Control Bonds (a) 2019-2025 (b) 2.55% 1.79%-3.05% 1.81%-3.05% 240.0 264.5 Notes Payable – Nonaffiliated (c) 2019-2024 2.49% 2.42%-2.80% 3.20%-3.38% 168.7 135.8 Spent Nuclear Fuel Obligation (e) 279.8 273.6 Other Long-term Debt 2021-2025 3.09% 2.93%-6.00% 3.66%-6.00% 211.0 212.5 Total Long-term Debt Outstanding $ 3,050.2 $ 3,035.4 OPCo Senior Unsecured Notes 2021-2049 5.20% 4.00%-6.60% 4.15%-6.60% $ 2,081.0 $ 1,635.5 Pollution Control Bonds 2038 5.80% — 32.3 Securitization Bonds 2019 (d) 2.049% — 47.8 Other Long-term Debt 2028 1.15% 1.15% 1.15% 1.0 1.0 Total Long-term Debt Outstanding $ 2,082.0 $ 1,716.6 PSO Senior Unsecured Notes 2019-2049 4.55% 3.05%-6.625% 3.05%-6.625% $ 1,245.6 $ 1,144.9 Pollution Control Bonds 2020 4.45% 4.45% 4.45% 12.7 12.6 Other Long-term Debt 2019-2027 3.19% 3.00%-3.20% 3.00%-3.72% 127.9 129.5 Total Long-term Debt Outstanding $ 1,386.2 $ 1,287.0 SWEPCo Senior Unsecured Notes 2022-2048 4.04% 2.75%-6.20% 2.75%-6.20% $ 2,428.9 $ 2,427.0 Pollution Control Bonds 2019 1.60% — 53.5 Notes Payable – Nonaffiliated (c) 2024-2032 5.26% 4.58%-6.37% 4.58%-6.37% 65.6 68.9 Other Long-term Debt 2020-2035 3.55% 3.08%-4.68% 3.75%-4.68% 161.1 164.0 Total Long-term Debt Outstanding $ 2,655.6 $ 2,713.4 (a) For certain series of Pollution Control Bonds, interest rates are subject to periodic adjustment. Certain series may be purchased on demand at periodic interest adjustment dates. Letters of credit from banks and insurance policies support certain series. (b) Certain Pollution Control Bonds are subject to redemption earlier than the maturity date. Consequently, these bonds have been classified for maturity purposes as Long-term Debt Due Within One Year - Nonaffiliated on the balance sheets. (c) Notes payable represent outstanding promissory notes issued under term loan agreements and credit agreements with a number of banks and other financial institutions. At expiration, all notes then issued and outstanding are due and payable. Interest rates are both fixed and variable. Variable rates generally relate to specified short-term interest rates. (d) Dates represent the scheduled final payment dates for the securitization bonds. The legal maturity date is one to two years later. These bonds have been classified for maturity and repayment purposes based on the scheduled final payment date. (e) Spent Nuclear Fuel Obligation consists of a liability along with accrued interest for disposal of SNF. See “Spent Nuclear Fuel Disposal” section of Note 6 for additional information. (f) See “Equity Units” section below for additional information. As of December 31, 2019 , outstanding long-term debt was payable as follows: AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) 2020 $ 1,598.7 $ 392.1 $ — $ 215.6 $ 139.7 $ 0.1 $ 13.2 $ 121.2 2021 2,022.7 88.7 50.0 393.0 291.5 500.1 250.5 6.2 2022 3,014.6 (a) 716.0 104.0 355.4 26.8 0.1 125.5 281.2 2023 739.9 218.5 60.0 26.6 259.2 0.1 0.6 6.2 2024 706.5 96.0 95.0 113.5 4.2 0.1 0.6 31.2 After 2024 18,863.1 3,081.4 3,156.0 3,296.9 2,355.3 1,600.5 1,001.4 2,231.7 Principal Amount 26,945.5 4,592.7 3,465.0 4,401.0 3,076.7 2,101.0 1,391.8 2,677.7 Unamortized Discount, Net and Debt Issuance Costs (220.0 ) (34.3 ) (37.7 ) (37.2 ) (26.5 ) (19.0 ) (5.6 ) (22.1 ) Total Long-term Debt Outstanding $ 26,725.5 $ 4,558.4 $ 3,427.3 $ 4,363.8 $ 3,050.2 $ 2,082.0 $ 1,386.2 $ 2,655.6 (a) Amount includes $805 million of Junior Subordinated Notes. See “Equity Units” section below for additional information. As of December 31, 2019 , trustees held, on behalf of AEP, $35 million of their reacquired Pollution Control Bonds. Of this total, $35 million related to OPCo. In January 2020, those Pollution Control Bonds were redeemed. Long-term Debt Subsequent Events In January and February 2020, AEP Texas retired $111 million and $3 million , respectively, of Securitization Bonds. In January and February 2020 , I&M retired $8 million and $5 million , respectively, of Notes Payable related to DCC Fuel. In January 2020 , Transource Energy issued $4 million of variable rate Other Long-term Debt due in 2023 . In February 2020, APCo retired $12 million of Securitization Bonds. Equity Units (Applies to AEP) In March 2019, AEP issued 16.1 million Equity Units initially in the form of corporate units, at a stated amount of $50 per unit, for a total stated amount of $805 million . Net proceeds from the issuance were approximately $785 million . The proceeds were used to support AEP’s overall capital expenditure plans including the acquisition of Sempra Renewables LLC. Each corporate unit represents a 1/20 undivided beneficial ownership interest in $1,000 principal amount of AEP’s 3.40% Junior Subordinated Notes (notes) due in 2024 and a forward equity purchase contract which settles after three years in 2022 . The notes are expected to be remarketed in 2022, at which time the interest rate will reset at the then current market rate. Investors may choose to remarket their notes to receive the remarketing proceeds and use those funds to settle the forward equity purchase contract, or accept the remarketed debt and use other funds for the equity purchase. If the remarketing is unsuccessful, investors have the right to put their notes to AEP at a price equal to the principal. The Equity Units carry an annual distribution rate of 6.125% , which is comprised of a quarterly coupon rate of interest of 3.40% and a quarterly forward equity purchase contract payment of 2.725% . Each forward equity purchase contract obligates the holder to purchase, and AEP to sell, for $50 a number of shares in common stock in accordance with the conversion ratios set forth below (subject to an anti-dilution adjustment): • If the AEP common stock market price is equal to or greater than $99.58 : 0.5021 shares per contract. • If the AEP common stock market price is less than $99.58 but greater than $82.98 : a number of shares per contract equal to $50 divided by the applicable market price. The holder receives a variable number of shares at $50. • If the AEP common stock market price is less than or equal to $82.98 : 0.6026 shares per contract. A holder’s ownership interest in the notes is pledged to AEP to secure the holder’s obligation under the related forward equity purchase contract. If a holder of the forward equity purchase contract chooses at any time to no longer be a holder of the notes, such holder’s obligation under the forward equity purchase contract must be secured by a U.S. Treasury security which must be equal to the aggregate principal amount of the notes. At the time of issuance, the $805 million of notes were recorded within Long-term Debt on the balance sheets. The present value of the purchase contract payments of $62 million were recorded in Deferred Credits and Other Noncurrent Liabilities with a current portion in Other Current Liabilities at the time of issuance, representing the obligation to make forward equity contract payments, with an offsetting reduction to Paid-in Capital. The difference between the face value and present value of the purchase contract payments will be accreted to Interest Expense on the statements of income over the three year period ending in 2022. The liability recorded for the contract payments is considered non-cash and excluded from the statements of cash flows. Until settlement of the forward equity purchase contract, earnings per share dilution resulting from the equity unit issuance will be determined under the treasury stock method. The maximum amount of shares AEP will be required to issue to settle the purchase contract is 9,701,860 shares (subject to an anti-dilution adjustment). Debt Covenants (Applies to AEP and AEPTCo) Covenants in AEPTCo’s note purchase agreements and indenture limit the amount of contractually-defined priority debt (which includes a further sub-limit of $50 million of secured debt) to 10% of consolidated tangible net assets. AEPTCo’s contractually-defined priority debt was 1.6% of consolidated tangible net assets as of December 31, 2019 . The method for calculating the consolidated tangible net assets is contractually-defined in the note purchase agreement. Dividend Restrictions Utility Subsidiaries’ Restrictions Parent depends on its utility subsidiaries to pay dividends to shareholders. AEP utility subsidiaries pay dividends to Parent provided funds are legally available. Various financing arrangements and regulatory requirements may impose certain restrictions on the ability of the subsidiaries to transfer funds to Parent in the form of dividends. All of the dividends declared by AEP’s utility subsidiaries that provide transmission or local distribution services are subject to a Federal Power Act restriction that prohibits the payment of dividends out of capital accounts without regulatory approval; payment of dividends is allowed out of retained earnings only. The Federal Power Act also creates a reserve on retained earnings attributable to hydroelectric generation plants. Because of their ownership of such plants, this reserve applies to AGR, APCo and I&M. Certain AEP subsidiaries have credit agreements that contain covenants that limit their debt to capitalization ratio to 67.5% . The method for calculating outstanding debt and capitalization is contractually-defined in the credit agreements. The most restrictive dividend limitation for certain AEP subsidiaries is through the Federal Power Act restriction, while for other AEP subsidiaries the most restrictive dividend limitation is through the credit agreements. As of December 31, 2019 , the maximum amount of restricted net assets of AEP’s subsidiaries that may not be distributed to the Parent in the form of a loan, advance or dividend was $13.2 billion . The Federal Power Act restriction limits the ability of the AEP subsidiaries owning hydroelectric generation to pay dividends out of retained earnings. Additionally, the credit agreement covenant restrictions can limit the ability of the AEP subsidiaries to pay dividends out of retained earnings. As of December 31, 2019 , the amount of any such restrictions were as follows: AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Restricted Retained Earnings $ 1,741.4 (a) $ 385.0 $ — $ 26.3 $ 524.5 $ — $ 153.0 $ 534.5 (a) Includes the restrictions of consolidated and non-consolidated subsidiaries. Parent Restrictions (Applies to AEP) The holders of AEP’s common stock are entitled to receive the dividends declared by the Board of Directors provided funds are legally available for such dividends. Parent’s income primarily derives from common stock equity in the earnings of its utility subsidiaries. Pursuant to the leverage restrictions in credit agreements, AEP must maintain a percentage of debt to total capitalization at a level that does not exceed 67.5%. The method for calculating outstanding debt and capitalization is contractually-defined in the credit agreements. As of December 31, 2019 , AEP had $7.2 billion of available retained earnings to pay dividends to common shareholders. AEP paid $1.3 billion , $1.3 billion and $1.2 billion of dividends to common shareholders for the years ended December 31, 2019 , 2018 and 2017 , respectively. Lines of Credit and Short-term Debt (Applies to AEP and SWEPCo) AEP uses its commercial paper program to meet the short-term borrowing needs of its subsidiaries. The program funds a Utility Money Pool, which funds AEP’s utility subsidiaries; a Nonutility Money Pool, which funds certain AEP nonutility subsidiaries; and the short-term debt requirements of subsidiaries that are not participating in either money pool for regulatory or operational reasons, as direct borrowers. As of December 31, 2019 , AEP had a $4 billion revolving credit facility to support its commercial paper program. The commercial paper program for the year ended 2019 , had a weighted-average interest rate of 2.51% and a maximum amount outstanding of $2.2 billion . AEP’s outstanding short-term debt was as follows: December 31, 2019 2018 Company Type of Debt Outstanding Amount Interest Rate (a) Outstanding Amount Interest Rate (a) (in millions) (in millions) AEP Securitized Debt for Receivables (b) $ 710.0 2.42 % $ 750.0 2.16 % AEP Commercial Paper 2,110.0 2.10 % 1,160.0 2.96 % SWEPCo Notes Payable 18.3 3.29 % — — % Total Short-term Debt $ 2,838.3 $ 1,910.0 (a) Weighted-average rate. (b) Amount of securitized debt for receivables as accounted for under the “Transfers and Servicing” accounting guidance. Corporate Borrowing Program – AEP System (Applies to Registrant Subsidiaries) The AEP System uses a corporate borrowing program to meet the short-term borrowing needs of AEP’s subsidiaries. The corporate borrowing program includes a Utility Money Pool, which funds AEP’s utility subsidiaries; a Nonutility Money Pool, which funds certain AEP nonutility subsidiaries; and direct borrowing from AEP. The AEP System Utility Money Pool operates in accordance with the terms and conditions of its agreement filed with the FERC. The amounts of outstanding loans to (borrowings from) the Utility Money Pool as of December 31, 2019 and 2018 are included in Advances to Affiliates and Advances from Affiliates, respectively, on the Registrant Subsidiaries’ balance sheets. The Utility Money Pool participants’ money pool activity and corresponding authorized borrowing limits are described in the following tables: Year Ended December 31, 2019 : Maximum Average Net Loans to Borrowings Maximum Borrowings Average (Borrowings from) Authorized from the Loans to the from the Loans to the the Utility Money Short-term Utility Utility Utility Utility Pool as of Borrowing Company Money Pool Money Pool Money Pool Money Pool December 31, 2019 Limit (in millions) AEP Texas $ 390.7 $ 213.1 $ 239.3 $ 194.4 $ 199.7 $ 500.0 AEPTCo 374.9 244.4 152.0 52.8 (119.0 ) 795.0 (a) APCo 270.0 232.2 115.9 51.9 (214.6 ) 500.0 I&M 158.8 66.0 71.5 16.2 (101.2 ) 500.0 OPCo 291.2 178.6 129.2 50.1 (131.0 ) 500.0 PSO 140.5 215.6 63.9 98.3 38.8 300.0 SWEPCo 105.1 81.4 53.3 13.6 (59.9 ) 350.0 Year Ended December 31, 2018 : Maximum Average Net Loans to Borrowings Maximum Borrowings Average (Borrowings from) Authorized from the Loans to the from the Loans to the the Utility Money Short-term Utility Utility Utility Utility Pool as of Borrowing Company Money Pool Money Pool Money Pool Money Pool December 31, 2018 Limit (in millions) AEP Texas $ 390.6 $ 106.9 $ 176.0 $ 47.1 $ (216.0 ) $ 500.0 AEPTCo 371.3 276.4 177.9 58.4 35.8 795.0 (a) APCo 295.5 23.7 175.3 23.3 (182.6 ) 600.0 I&M 322.1 657.8 255.5 110.7 11.6 500.0 OPCo 270.8 225.0 167.8 189.4 (114.1 ) 500.0 PSO 193.7 31.8 104.5 12.9 (105.5 ) 300.0 SWEPCo 200.1 533.7 143.2 268.1 81.4 350.0 (a) Amount represents the combined authorized short-term borrowing limit the State Transcos have from FERC or state regulatory commissions. The activity in the above tables does not include short-term lending activity of certain AEP nonutility subsidiaries. AEP Texas’ wholly-owned subsidiary, AEP Texas North Generation Company, LLC and SWEPCo’s wholly-owned subsidiary, Mutual Energy SWEPCo, LLC participate in the Nonutility Money Pool. The amounts of outstanding loans to the Nonutility Money Pool as of December 31, 2019 and 2018 are included in Advances to Affiliates on each subsidiaries’ balance sheets. The Nonutility Money Pool participants’ money pool activity is described in the following tables: Year Ended December 31, 2019 : Maximum Loans Average Loans Loans to the Nonutility to the Nonutility to the Nonutility Money Pool as of Company Money Pool Money Pool December 31, 2019 (in millions) AEP Texas $ 8.0 $ 7.7 $ 7.5 SWEPCo 2.1 2.0 2.1 Year Ended December 31, 2018 : Maximum Loans Average Loans Loans to the Nonutility to the Nonutility to the Nonutility Money Pool as of Company Money Pool Money Pool December 31, 2018 (in millions) AEP Texas $ 8.4 $ 8.1 $ 8.0 SWEPCo 2.0 2.0 2.0 AEP has a direct financing relationship with AEPTCo to meet its short-term borrowing needs. The amounts of outstanding loans to and borrowings from AEP as of December 31, 2019 and 2018 are included in Advances to Affiliates and Advances from Affiliates, respectively, on AEPTCo’s balance sheets. AEPTCo’s direct financing activities with AEP and corresponding authorized borrowing limits are described in the following tables: Year Ended December 31, 2019 : Maximum Maximum Average Average Borrowings from Loans to Authorized Borrowings Loans Borrowings Loans AEP as of AEP as of Short-term from AEP to AEP from AEP to AEP December 31, 2019 December 31, 2019 Borrowing Limit (in millions) $ 1.3 $ 153.5 $ 1.3 $ 68.0 $ 1.3 $ 68.7 $ 75.0 (a) Year Ended December 31, 2018 : Maximum Maximum Average Average Borrowings from Loans to Authorized Borrowings Loans Borrowings Loans AEP as of AEP as of Short-term from AEP to AEP from AEP to AEP December 31, 2018 December 31, 2018 Borrowing Limit (in millions) $ 1.2 $ 104.7 $ 1.1 $ 49.8 $ 1.2 $ 16.9 $ 75.0 (a) (a) Amount represents the combined authorized short-term borrowing limit the State Transcos have from FERC or state regulatory commissions. The maximum and minimum interest rates for funds either borrowed from or loaned to the Utility Money Pool are summarized in the following table: Years Ended December 31, 2019 2018 2017 Maximum Interest Rate 3.43 % 2.97 % 1.85 % Minimum Interest Rate 1.77 % 1.81 % 0.92 % The average interest rates for funds borrowed from and loaned to the Utility Money Pool are summarized in the following table: Average Interest Rate for Funds Borrowed from the Utility Money Pool for the Years Ended December 31, Average Interest Rate for Funds Loaned to the Utility Money Pool for the Years Ended December 31, Company 2019 2018 2017 2019 2018 2017 AEP Texas 2.63 % 2.26 % 1.29 % 2.03 % 2.29 % 1.26 % AEPTCo 2.64 % 2.27 % 1.36 % 2.41 % 2.10 % 1.27 % APCo 2.45 % 2.26 % 1.28 % 2.66 % 2.21 % 1.29 % I&M 2.34 % 2.16 % 1.27 % 2.60 % 2.08 % 1.29 % OPCo 2.67 % 2.18 % 1.37 % 2.68 % 2.47 % 0.98 % PSO 2.85 % 2.27 % 1.32 % 2.27 % 1.98 % — % SWEPCo 2.72 % 2.31 % 1.28 % 2.22 % 2.00 % 0.98 % Maximum, minimum and average interest rates for funds either borrowed from or loaned to the Nonutility Money Pool are summarized in the following table: Maximum Interest Rate Minimum Interest Rate Average Interest Rate Year Ended for Funds Loaned to for Funds Loaned to for Funds Loaned to December 31, Company the Nonutility Money Pool the Nonutility Money Pool the Nonutility Money Pool 2019 AEP Texas 3.02 % 1.91 % 2.56 % 2019 SWEPCo 3.02 % 1.91 % 2.55 % 2018 AEP Texas 2.97 % 1.83 % 2.36 % 2018 SWEPCo 2.97 % 1.83 % 2.36 % 2017 AEP Texas 1.85 % — % 1.32 % 2017 SWEPCo 1.85 % — % 1.32 % AEPTCo’s maximum, minimum and average interest rates for funds either borrowed from or loaned to AEP are summarized in the following table: Maximum Minimum Maximum Minimum Average Average Interest Rate Interest Rate Interest Rate Interest Rate Interest Rate Interest Rate for Funds for Funds for Funds for Funds for Funds for Funds Year Ended Borrowed from Borrowed from Loaned to Loaned to Borrowed from Loaned to December 31, AEP AEP AEP AEP AEP AEP 2019 3.02 % 1.91 % 3.02 % 1.91 % 2.55 % 2.51 % 2018 2.97 % 1.76 % 2.97 % 1.76 % 2.36 % 2.36 % 2017 1.85 % 0.92 % 1.85 % 0.92 % 1.33 % 1.36 % Interest expense and interest income related to the Utility Money Pool, Nonutility Money Pool and direct borrowing financing relationship are included in Interest Expense and Interest Income, respectively, on each of the Registrant Subsidiaries’ statements of income. The interest expense and interest income related to the corporate borrowing programs were immaterial for the years ended December 31, 2019 , 2018 and 2017 . Credit Facilities See “Letters of Credit” section of Note 6 for additional information. Securitized Accounts Receivables – AEP Credit (Applies to AEP) AEP Credit has a receivables securitization agreement that provides a commitment of $750 million from bank conduits to purchase receivables and expires in July 2021. Under the securitization agreement, AEP Credit receives financing from the bank conduits for the interest in the receivables AEP Credit acquires from affiliated utility subsidiaries. These securitized transactions allow AEP Credit to repay its outstanding debt obligations, continue to purchase the operating companies’ receivables and accelerate AEP Credit’s cash collections. Accounts receivable information for AEP Credit was as follows: Years Ended December 31, 2019 2018 2017 (dollars in millions) Effective Interest Rates on Securitization of Accounts Receivable 2.42 % 2.16 % 1.22 % Net Uncollectible Accounts Receivable Written Off $ 26.6 $ 27.6 $ 23.4 December 31, 2019 2018 (in millions) Accounts Receivable Retained Interest and Pledged as Collateral Less Uncollectible Accounts $ 841.8 $ 972.5 Short-term – Securitized Debt of Receivables 710.0 750.0 Delinquent Securitized Accounts Receivable 39.6 50.3 Bad Debt Reserves Related to Securitization 32.1 27.5 Unbilled Receivables Related to Securitization 266.8 281.4 AEP Credit’s delinquent customer accounts receivable represent accounts greater than 30 days past due. Securitized Accounts Receivables – AEP Credit (Applies to Registrant Subsidiaries, except AEPTCo and AEP Texas) Under this sale of receivables arrangement, the Registrant Subsidiaries sell, without recourse, certain of their customer accounts receivable and accrued unbilled revenue balances to AEP Credit and are charged a fee based on AEP Credit’s financing costs, administrative costs and uncollectible accounts experience for each Registrant Subsidiary’s receivables. APCo does not have regulatory authority to sell its West Virginia accounts receivable. The costs of customer accounts receivable sold are reported in Other Operation expense on the Registrant Subsidiaries’ statements of income. The Registrant Subsidiaries manage and service their customer accounts receivable, which are sold to AEP Credit. AEP Credit securitizes the eligible receivables for the operating companies and retains the remainder. The amount of accounts receivable and accrued unbilled revenues under the sale of receivables agreement were: December 31, Company 2019 2018 (in millions) APCo $ 120.9 $ 133.3 I&M 141.8 152.9 OPCo 330.3 395.2 PSO 101.1 109.7 SWEPCo 125.2 150.3 The fees paid to AEP Credit for customer accounts receivable sold were: Years Ended December 31, Company 2019 2018 2017 (in millions) APCo $ 7.4 $ 7.0 $ 5.6 I&M 11.1 9.2 6.7 OPCo 27.1 26.3 21.7 PSO 7.8 7.9 7.0 SWEPCo 10.2 8.9 7.2 The proceeds on the sale of receivables to AEP Credit were: Years Ended December 31, Company 2019 2018 2017 (in millions) APCo $ 1,310.3 $ 1,421.0 $ 1,372.8 I&M 1,824.2 1,843.0 1,612.9 OPCo 2,293.6 2,674.5 2,339.0 PSO 1,442.5 1,484.6 1,337.0 SWEPCo 1,618.5 1,736.1 1,563.4

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2019
Stock-based Compensation	STOCK-BASED COMPENSATION The disclosures in this note apply to AEP only. The impact of AEP’s share-based compensation plans is insignificant to the financial statements of the Registrant Subsidiaries. Awards under AEP’s long-term incentive plan may be granted to employees and directors. The Amended and Restated American Electric Power System Long-Term Incentive Plan (the “Prior Plan”), was replaced prospectively for new grants by the American Electric Power System 2015 Long-Term Incentive Plan (the “2015 LTIP”) effective in April 2015. The 2015 LTIP was subsequently amended in September 2016. The 2015 LTIP provides for a maximum of 10 million AEP common shares to be available for grant to eligible employees and directors. As of December 31, 2019 , 7,667,992 shares remained available for issuance under the 2015 LTIP. No new awards may be granted under the Prior Plan. The 2015 LTIP awards may be stock options, stock appreciation rights, restricted stock, restricted stock units, performance shares, performance units, cash-based awards and other stock-based awards. Shares issued pursuant to a stock option or a stock appreciation right reduce the shares remaining available for grants under the 2015 LTIP by 0.286 of a share. Shares issued for any other awards that settles in AEP stock reduce the shares remaining available for grants under the 2015 LTIP by one share. Cash settled awards do not reduce the number of shares remaining available under the 2015 LTIP. The following sections provide further information regarding each type of stock-based compensation award granted under these plans. Performance Shares Performance units granted prior to 2017 were settled in cash rather than AEP common stock and did not reduce the number of shares remaining available under the 2015 LTIP. Those performance units had a fair value upon vesting equal to the average closing market price of AEP common stock for the last 20 trading days of the performance period. Performance shares granted in and after 2017 are settled in AEP common stock and will reduce the aggregate share authorization. In all cases the number of performance shares held at the end of the three -year performance period is multiplied by the performance score for such period to determine the actual number of performance shares that participants realize. The performance score can range from 0% to 200% and is determined at the end of the performance period based on performance measures, which include both performance and market conditions, established for each grant at the beginning of the performance period by the Human Resources Committee of AEP’s Board of Directors (HR Committee). Certain employees must satisfy a minimum stock ownership requirement. If those employees have not met their stock ownership requirement, a portion or all of their performance shares are mandatorily deferred as AEP career shares to the extent needed to meet their stock ownership requirement. AEP career shares are a form of non-qualified deferred compensation that has a value equivalent to a share of AEP common stock. AEP career shares are settled in AEP common stock after the participant’s termination of employment. AEP career shares are recorded in Paid-in Capital on the balance sheets. Amounts equivalent to cash dividends on both performance shares and AEP career shares accrue as additional shares. Management records compensation cost for performance shares over an approximately three-year vesting period. The liability for the pre-2017 performance units was recorded in Employee Benefits and Pension Obligations on the balance sheets and was adjusted for changes in value. Performance shares are recorded as mezzanine equity on the balance sheets and compensation cost is calculated at fair value using two equally weighted metrics. The first metric is a total shareholder return measure, which is valued based on a third-party Monte Carlo valuation. The value related to this metric does not change over the three-year vesting period. The second metric is a three-year cumulative earnings per share metric which is adjusted quarterly for changes in performance relative to a target approved by the HR Committee. The HR Committee awarded performance shares and reinvested dividends on outstanding performance shares and AEP career shares as follows: Years Ended December 31, Performance Shares 2019 2018 2017 Awarded Shares (in thousands) 535.0 581.4 590.7 Weighted Average Share Fair Value at Grant Date $ 83.21 $ 67.21 $ 69.78 Vesting Period (in years) 3 3 3 Performance Shares and AEP Career Shares (Reinvested Dividends Portion) Years Ended December 31, 2019 2018 2017 Awarded Shares (in thousands) (a) 66.4 80.2 74.6 Weighted Average Fair Value at Grant Date $ 88.73 $ 70.58 $ 72.35 Vesting Period (in years) (b) (b) (b) (a) All awarded dividends in 2019 were equity awards and awarded dividends in both 2018 and 2017 were a mix of equity awards and liability awards. (b) The vesting period for the reinvested dividends on performance shares is equal to the remaining life of the related performance shares. Dividends on AEP career shares vest immediately when the dividend is awarded but are not settled in AEP common stock until after the participant’s AEP employment ends. Performance scores and final awards are determined and approved by the HR Committee in accordance with the pre-established performance measures within approximately two months after the end of the performance period. The performance scores for all performance periods were dependent on two equally-weighted performance measures: (a) three -year total shareholder return measured relative to a peer group of similar companies and (b) three -year cumulative earnings per share measured relative to a target approved by the HR Committee. The certified performance scores and shares earned for the three-year periods were as follows: Years Ended December 31, Performance Shares 2019 2018 2017 Certified Performance Score 132.7 % 136.7 % 164.8 % Performance Shares Earned 792,897 820,780 956,055 Performance Shares Mandatorily Deferred as AEP Career Shares 10,063 11,248 20,213 Performance Shares Voluntarily Deferred into the Incentive Compensation Deferral Program 49,392 56,826 47,177 Performance Shares to be Settled (a) 733,442 752,706 888,665 (a) Performance shares settled for the three-year period ended December 31, 2019 settled in AEP common stock. Performance units settled for the three-year period ended December 31, 2018 and 2017 settled in cash. The settlements were as follows: Years Ended December 31, Performance Units and AEP Career Shares 2019 2018 2017 (in millions) Cash Settlements for Performance Units $ 58.3 $ 66.9 $ 64.9 AEP Common Stock Settlements for Career Share Distributions 6.6 5.1 0.4 A summary of the status of AEP’s nonvested Performance Shares as of December 31, 2019 and changes during the year ended December 31, 2019 were as follows: Nonvested Performance Shares Shares Weighted Average Grant Date Fair Value (in thousands) Nonvested as of January 1, 2019 1,171.3 $ 66.01 Granted 582.5 80.30 Vested (a) (597.5 ) 65.42 Forfeited (42.9 ) 70.32 Nonvested as of December 31, 2019 1,113.4 73.64 (a) The vested Performance Shares will be converted to 733 thousand shares based on the closing share price on the day before settlement. Monte Carlo Valuation AEP engages a third-party for a Monte Carlo valuation to calculate half of the fair value for the performance shares awarded during and after 2017. The valuations use a lattice model and the expected volatility assumptions used were the historical volatilities for AEP and the members of their peer group. The assumptions used in the Monte Carlo valuations were as follows: Years Ended December 31, Monte Carlo Valuation 2019 2018 2017 Valuation Period (in years) (a) 2.87 2.87 2.86 Expected Volatility Minimum 14.83 % 14.77 % 15.65 % Expected Volatility Maximum 25.57 % 26.72 % 27.19 % Expected Volatility Average 17.39 % 17.90 % 19.07 % Dividend Rate (b) — % — % — % Risk Free Rate 2.49 % 2.34 % 1.44 % (a) Period from award date to vesting date. (b) Equivalent to reinvesting dividends. Restricted Stock Units The HR Committee grants restricted stock units (RSUs), which generally vest, subject to the participant’s continued employment, over at least three years in approximately equal annual increments. The RSUs accrue dividends as additional RSUs. The additional RSUs granted as dividends vest on the same date as the underlying RSUs. RSUs are converted into shares of AEP common stock upon vesting, except the RSUs granted prior to 2017 to AEP’s executive officers which settled in cash. Executive officers are those officers who are subject to the disclosure requirements set forth in Section 16 of the Securities Exchange Act of 1934. For RSUs that settle in shares, compensation cost is measured at fair value on the grant date and recorded over the vesting period. Fair value is determined by multiplying the number of RSUs granted by the grant date market closing price. For RSUs that settled in cash, compensation cost is recorded over the vesting period and adjusted for changes in fair value until vested. The fair value at vesting was determined by multiplying the number of RSUs vested by the 20 -day average closing price of AEP common stock. The maximum contractual term of outstanding RSUs is approximately 40 months from the grant date. The HR Committee awarded RSUs, including additional units awarded as dividends, as follows: Years Ended December 31, Restricted Stock Units 2019 2018 2017 Awarded Units (in thousands) 304.8 260.0 255.8 Weighted Average Grant Date Fair Value $ 81.57 $ 67.96 $ 65.26 The total fair value and total intrinsic value of restricted stock units vested were as follows: Years Ended December 31, Restricted Stock Units 2019 2018 2017 (in millions) Fair Value of Restricted Stock Units Vested $ 16.3 $ 16.6 $ 16.1 Intrinsic Value of Restricted Stock Units Vested (a) 21.6 19.2 20.0 (a) Intrinsic value is calculated as market price at exercise date. A summary of the status of AEP’s nonvested RSUs as of December 31, 2019 and changes during the year ended December 31, 2019 were as follows: Nonvested Restricted Stock Units Shares/Units Weighted Average Grant Date Fair Value (in thousands) Nonvested as of January 1, 2019 489.1 $ 66.01 Granted 304.8 81.57 Vested (253.7 ) 64.44 Forfeited (23.3 ) 70.27 Nonvested as of December 31, 2019 516.9 75.55 The total aggregate intrinsic value of nonvested RSUs as of December 31, 2019 was $49 million and the weighted average remaining contractual life was 1.79 years . Other Stock-Based Plans AEP also has a Stock Unit Accumulation Plan for Non-Employee Directors providing each non-employee director with AEP stock units as a substantial portion of their quarterly compensation for their services as a director. The number of stock units provided is based on the closing price of AEP common stock on the last trading day of the quarter for which the stock units were earned. Amounts equivalent to cash dividends on the stock units accrue as additional AEP stock units. The stock units granted to non-employee directors are fully vested on their grant date. Stock units are settled in cash upon termination of board service or up to 10 years later if the participant so elects. Cash settlements for stock units are calculated based on the average closing price of AEP common stock for the last 20 trading days prior to the distribution date. After five years of service on the Board of Directors, non-employee directors receive subsequent AEP stock units as contributions to an AEP stock fund awarded under the Stock Unit Accumulation Plan. Such amounts may be exchanged into other market-based investments that are similar to the investment options available to employees that participate in AEP’s Incentive Compensation Deferral Plan. Management records compensation cost for stock units when the units are awarded and adjusts the liability for changes in value based on the current 20 -day average closing price of AEP common stock on the valuation date. For the years ended December 31, 2019 , 2018 and 2017 , cash settlements for stock unit distributions were immaterial. The Board of Directors awarded stock units, including units awarded for dividends, as follows: Years Ended December 31, Stock Unit Accumulation Plan for Non-Employee Directors 2019 2018 2017 Awarded Units (in thousands) 10.0 11.4 14.8 Weighted Average Grant Date Fair Value $ 89.13 $ 70.41 $ 70.79 Share-based Compensation Plans For share-based payment arrangements the compensation cost, the actual tax benefit from the tax deductions for compensation cost recognized in income and the total compensation cost capitalized were as follows: Years Ended December 31, Share-based Compensation Plans 2019 2018 2017 (in millions) Compensation Cost for Share-based Payment Arrangements (a) $ 57.9 $ 53.2 $ 79.5 Actual Tax Benefit (b) 8.4 7.7 18.9 Total Compensation Cost Capitalized 20.0 19.7 26.4 (a) Compensation cost for share-based payment arrangements is included in Other Operation and Maintenance expenses on the statements of income. (b) In December 2017, Tax Reform modified Section 162(m) of the Internal Revenue Code. Beginning after 2017, AEP can generally no longer deduct certain compensation expense in excess of $1 million for certain named executive officers. This will reduce the tax benefit going forward. As of December 31, 2019 , there was $73 million of total unrecognized compensation cost related to unvested share-based compensation arrangements granted under the 2015 LTIP. Unrecognized compensation cost related to unvested share-based arrangements will change as the fair value of performance shares are adjusted each period and as forfeitures for all award types are realized. AEP’s unrecognized compensation cost will be recognized over a weighted-average period of 1.43 years . Under the 2015 LTIP, AEP is permitted to use authorized but unissued shares, treasury shares, shares acquired in the open market specifically for distribution under these plans, or any combination thereof to fulfill share commitments. AEP’s current practice is to use authorized but unissued shares to fulfill share commitments. The number of shares used to fulfill share commitments is generally reduced to offset AEP’s tax withholding obligation.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2019
Related Party Transactions	RELATED PARTY TRANSACTIONS The disclosures in this note apply to all Registrant Subsidiaries unless indicated otherwise. For other related party transactions, also see “AEP System Tax Allocation Agreement” section of Note 12 in addition to “Corporate Borrowing Program – AEP System” and “Securitized Accounts Receivables – AEP Credit” sections of Note 14 . Power Coordination Agreement (Applies to all Registrant Subsidiaries except AEP Texas and AEPTCo) Effective January 1, 2014, the FERC approved the PCA. Under the PCA, APCo, I&M, KPCo and WPCo are individually responsible for planning their respective capacity obligations. The PCA allows, but does not obligate, APCo, I&M, KPCo and WPCo to participate collectively under a common fixed resource requirement capacity plan in PJM and to participate in specified collective off-system sales and purchase activities. AEPSC conducts power, capacity, coal, natural gas, interest rate and, to a lesser extent, heating oil, gasoline and other risk management activities on behalf of APCo, I&M, KPCo, PSO, SWEPCo and WPCo. Certain power and natural gas risk management activities for APCo, I&M, KPCo and WPCo are allocated based on the four member companies’ respective equity positions, while power and natural gas risk management activities for PSO and SWEPCo are allocated based on the Operating Agreement. With the transfer of OPCo’s generation assets to AGR in 2014, AEPSC conducts only gasoline, diesel fuel, energy procurement and risk management activities on OPCo’s behalf. System Integration Agreement (Applies to APCo, I&M, PSO and SWEPCo) Under the SIA, AEPSC allocates physical and financial revenues and expenses from transactions with neighboring utilities, power marketers and other power and natural gas risk management activities based upon the location of such activity. Margins resulting from trading and marketing activities originating in PJM generally accrue to the benefit of APCo, I&M, KPCo and WPCo, while trading and marketing activities originating in SPP generally accrue to the benefit of PSO and SWEPCo. Margins resulting from other transactions are allocated among APCo, I&M, KPCo, PSO, SWEPCo and WPCo based upon the equity positions of these companies. Affiliated Revenues and Purchases The tables below represent revenues from affiliates, net of respective provisions for refund, by type of revenue for the Registrant Subsidiaries: Related Party Revenues AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Year Ended December 31, 2019 Direct Sales to East Affiliates $ — $ — $ 128.6 $ — $ — $ — $ — Direct Sales to West Affiliates — — — — — — — Auction Sales to OPCo (a) — — 11.4 6.7 — — — Direct Sales to AEPEP 157.2 — — — — — (0.1 ) Transmission Revenues — 795.5 58.5 0.7 7.7 1.3 3.6 Other Revenues 3.3 11.2 6.8 3.1 19.6 4.8 1.4 Total Affiliated Revenues $ 160.5 $ 806.7 $ 205.3 $ 10.5 $ 27.3 $ 6.1 $ 4.9 Related Party Revenues AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Year Ended December 31, 2018 Direct Sales to East Affiliates $ — $ — $ 133.2 $ 0.1 $ — $ — $ — Direct Sales to West Affiliates — — — — — — — Auction Sales to OPCo (a) — — 5.8 7.1 — — — Direct Sales to AEPEP 103.6 — — — — — — Transmission Revenues — 591.4 36.4 11.7 3.9 0.9 26.9 Other Revenues 1.6 7.5 6.0 3.2 17.1 4.5 1.5 Total Affiliated Revenues $ 105.2 $ 598.9 $ 181.4 $ 22.1 $ 21.0 $ 5.4 $ 28.4 Related Party Revenues AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Year Ended December 31, 2017 Direct Sales to East Affiliates $ — $ — $ 130.4 $ — $ — $ — $ — Direct Sales to West Affiliates — — — 3.8 — — — Auction Sales to OPCo (a) — — 1.0 — — — — Direct Sales to AEPEP 63.6 — — — — — (0.2 ) Transmission Revenues — 559.6 34.1 (4.4 ) 6.2 — 24.2 Other Revenues 2.1 8.5 6.5 2.4 18.2 4.3 1.9 Total Affiliated Revenues $ 65.7 $ 568.1 $ 172.0 $ 1.8 $ 24.4 $ 4.3 $ 25.9 (a) Refer to the Ohio Auctions section below for further information regarding these amounts. The tables below represent the purchased power expenses incurred for purchases from affiliates. AEP Texas, AEPTCo, APCo, PSO and SWEPCo did not purchase any power from affiliates for the years ended December 31, 2019 , 2018 and 2017 . Related Party Purchases I&M OPCo (in millions) Year Ended December 31, 2019 Auction Purchases from AEPEP (a) $ — $ 64.6 Auction Purchases from AEP Energy (a) — 69.9 Auction Purchases from AEPSC (a) — 21.5 Direct Purchases from AEGCo 214.9 — Total Affiliated Purchases $ 214.9 $ 156.0 Related Party Purchases I&M OPCo (in millions) Year Ended December 31, 2018 Auction Purchases from AEPEP (a) $ — $ 79.7 Auction Purchases from AEP Energy (a) — 41.0 Auction Purchases from AEPSC (a) — 14.6 Direct Purchases from AEGCo 237.9 — Total Affiliated Purchases $ 237.9 $ 135.3 Related Party Purchases I&M OPCo (in millions) Year Ended December 31, 2017 Auction Purchases from AEPEP (a) $ — $ 96.5 Auction Purchases from AEP Energy (a) — 5.5 Auction Purchases from AEPSC (a) — 6.5 Direct Purchases from AEGCo 223.9 — Total Affiliated Purchases $ 223.9 $ 108.5 (a) Refer to the Ohio Auctions section below for further information regarding this amount. The above summarized related party revenues and expenses are reported in Sales to AEP Affiliates and Purchased Electricity from AEP Affiliates, respectively, on the Registrant Subsidiaries’ statements of income. Since the Registrant Subsidiaries are included in AEP’s consolidated results, the above summarized related party transactions are eliminated in total in AEP’s consolidated revenues and expenses. PJM and SPP Transmission Service Charges (Applies to all Registrant Subsidiaries except AEP Texas) APCo, I&M, KGPCo, KPCo, OPCo and WPCo (AEP East Companies) are parties to the Transmission Agreement (TA), which defines how transmission costs through the PJM OATT are allocated among the AEP East Companies on a 12-month average coincident peak basis. Additional costs for transmission services provided by AEPTCo and other transmission affiliates are billed to AEP East Companies through the PJM OATT. The following table shows the net transmission service charges recorded by APCo, I&M and OPCo: Years Ended December 31, Company 2019 2018 2017 (in millions) APCo $ 222.3 $ 128.3 $ 158.2 I&M 143.5 91.4 103.8 OPCo 373.4 210.1 248.6 The charges shown above are recorded in Other Operation expenses on the statements of income. PSO, SWEPCo and AEPSC are parties to the Transmission Coordination Agreement (TCA) in connection with the operation of the transmission assets of PSO and SWEPCo. The TCA has been approved by the FERC and establishes a coordinating committee, which is charged with overseeing the coordinated planning of the transmission facilities of the parties to the agreement. This includes the performance of transmission planning studies, the interaction of such companies with independent system operators and other regional bodies interested in transmission planning and compliance with the terms of the OATT filed with the FERC and the rules of the FERC relating to such a tariff. Under the TCA, the parties to the agreement delegated to AEPSC the responsibility of monitoring the reliability of their transmission systems and administering the OATT on their behalf. The allocations have been governed by the FERC-approved OATT for the SPP. Additional costs for transmission services provided by AEPTCo and other transmission affiliates are billed to PSO and SWEPCo through the SPP OATT. The following table shows the net transmission service charges recorded by PSO and SWEPCo: Years Ended December 31, Company 2019 2018 2017 (in millions) PSO $ 46.9 $ 65.9 $ 56.0 SWEPCo 20.1 10.5 6.6 The charges shown above are recorded in Other Operation expenses on the statements of income. AEPTCo provides transmission services to affiliates in accordance with the OATT, TA and TCA. AEPTCo recorded affiliated transmission revenues in Sales to AEP Affiliates on the statements of income. Refer to the Affiliated Revenues and Purchases section above for amounts related to these transactions. ERCOT Transmission Service Charges (Applies to AEP and AEP Texas) Pursuant to an order from the PUCT, ETT bills AEP Texas for its ERCOT wholesale transmission services. ETT billed AEP Texas $27 million , $27 million and $30 million for transmission services in 2019 , 2018 and 2017 , respectively. The billings are recorded in Other Operation expenses on AEP Texas’ statements of income. Oklaunion PPA between AEP Texas and AEPEP (Applies to AEP Texas) In 2007, AEP Texas entered into a PPA with an affiliate, AEPEP, whereby AEP Texas agrees to sell AEPEP 100% of AEP Texas’ capacity and associated energy from its undivided interest ( 54.69% ) in the Oklaunion Power Station. AEPEP pays AEP Texas for the capacity and associated energy delivered to the delivery point, the sum of fuel, operation and maintenance, depreciation, capacity and all taxes other than federal income taxes applicable. A portion of the payment is fixed and is payable regardless of the level of output. There are no penalties if AEP Texas fails to maintain a minimum availability level or exceeds a maximum heat rate level. The PPA was approved by the FERC. AEP Texas recognizes revenues for the fuel, operations and maintenance and all other taxes as billed. Revenue is recognized for the capacity and depreciation billed to AEPEP, on a straight-line basis over the term of the PPA as these represent the minimum payments due. In September 2018, the co-owners of Oklaunion Power Station voted to close the plant in 2020. Effective October 2018, AEP Texas increased depreciation expense to ensure the plant balances are fully depreciated as of September 2020 and recovered through the PPA billings to AEPEP. Under the early termination provisions of the PPA, AEPEP expects to pay AEP Texas the full Property, Plant and Equipment balance through depreciation payments over the remaining period of operation of the plant, which is currently estimated to be September 2020. AEP Texas recorded revenue of $157 million , $104 million and $64 million from AEPEP for the years ended December 31, 2019 , 2018 and 2017 , respectively. These amounts are included in Sales to AEP Affiliates on AEP Texas’ statements of income. Joint License Agreement (Applies to AEPTCo, APCo, I&M, OPCo and PSO) AEPTCo entered into a 50-year joint license agreement with APCo, I&M, KPCo, OPCo and PSO, respectively, allowing either party to occupy the granting party’s facilities or real property. In addition, AEPTCo entered into a 5-year joint license agreement with APCo and WPCo. After the expiration of these agreements, the term shall automatically renew for successive one-year terms unless either party provides notice. The joint license billing provides compensation to the granting party for the cost of carrying assets, including depreciation expense, property taxes, interest expense, return on equity and income taxes. AEPTCo recorded the following costs in Other Operation expense related to these agreements: Years Ended December 31, Billing Company 2019 2018 2017 (in millions) APCo $ 0.2 $ — $ — I&M 1.5 2.2 1.4 KPCo 0.3 0.2 0.2 OPCo 2.2 2.9 2.4 PSO 0.3 0.3 0.3 WPCo 0.1 — — APCo, I&M, KPCo, OPCo, PSO and WPCo recorded income related to these agreements in Sales to AEP Affiliates on the statements of income. Ohio Auctions (Applies to APCo, I&M and OPCo) In connection with OPCo’s June 2012 - May 2015 ESP, the PUCO ordered OPCo to conduct energy and capacity auctions for its entire SSO load for delivery beginning in June 2015. AEP Energy, AEPEP, APCo, KPCo, I&M and WPCo participate in the auction process and have been awarded tranches of OPCo’s SSO load. Refer to the Affiliated Revenues and Purchases section above for amounts related to these transactions and see “Ohio ESP Filings” section of Note 4 for additional information. Unit Power Agreements (Applies to I&M) UPA between AEGCo and I&M A UPA between AEGCo and I&M (the I&M Power Agreement) provides for the sale by AEGCo to I&M of all the power (and the energy associated therewith) available to AEGCo at the Rockport Plant unless it is sold to another utility. Subsequently, I&M assigns 30% of the power to KPCo. See the “UPA between AEGCo and KPCo” section below. I&M is obligated, whether or not power is available from AEGCo, to pay as a demand charge for the right to receive such power (and as an energy charge for any associated energy taken by I&M) net of amounts received by AEGCo from any other sources, sufficient to enable AEGCo to pay all its operating and other expenses, including a rate of return on the common equity of AEGCo as approved by the FERC. The I&M Power Agreement will continue in effect until the expiration of the lease term of Unit 2 of the Rockport Plant unless extended in specified circumstances. UPA between AEGCo and KPCo Pursuant to an assignment between I&M and KPCo and a UPA between AEGCo and KPCo, AEGCo sells KPCo 30% of the power (and the energy associated therewith) available to AEGCo from both units of the Rockport Plant. KPCo pays to AEGCo in consideration for the right to receive such power the same amounts which I&M would have paid AEGCo under the terms of the I&M Power Agreement for such entitlement. The KPCo UPA ends in December 2022. Cook Coal Terminal (Applies to I&M, PSO and SWEPCo) Cook Coal Terminal, which is owned by AEGCo, performs coal transloading and storage services at cost for I&M. The coal transloading costs were $13 million , $12 million and $10 million in 2019 , 2018 and 2017 , respectively. I&M recorded the cost of transloading services in Fuel on the balance sheets. Cook Coal Terminal also performs railcar maintenance services at cost for I&M, PSO and SWEPCo. The railcar maintenance costs were as follows: Years Ended December 31, Company 2019 2018 2017 (in millions) I&M $ 1.3 $ 1.5 $ 1.3 PSO 0.8 0.7 0.5 SWEPCo 4.0 3.4 3.5 I&M, PSO and SWEPCo recorded the cost of the railcar maintenance services in Fuel on the balance sheets. I&M Barging, Urea Transloading and Other Services (Applies to APCo and I&M) I&M provides barging, urea transloading and other transportation services to affiliates. Urea is a chemical used to control NO x emissions at certain generation plants in the AEP System. I&M recorded revenues from barging, transloading and other services in Other Revenues – Affiliated on the statements of income. The affiliated companies recorded these costs paid to I&M as fuel expenses or other operation expenses. The amounts of affiliated expenses were: Years Ended December 31, Company 2019 2018 2017 (in millions) AEGCo $ 14.9 $ 19.9 $ 15.3 AGR — — 0.1 APCo 38.9 35.1 37.2 KPCo 4.8 4.2 5.0 WPCo 4.8 4.2 5.0 Central Machine Shop (Applies to APCo, I&M, PSO and SWEPCo) APCo operates a facility which repairs and rebuilds specialized components for the generation plants across the AEP System. APCo defers the cost of performing these services on the balance sheet and then transfers the cost to the affiliate for reimbursement. The AEP subsidiaries recorded these billings as capital or maintenance expenses depending on the nature of the services received. These billings are recoverable from customers. The following table provides the amounts billed by APCo to the following affiliates: Years Ended December 31, Company 2019 2018 2017 (in millions) AGR $ 0.8 $ 1.6 $ 1.2 I&M 2.3 2.4 2.7 KPCo 1.4 1.7 1.8 PSO 1.1 0.5 1.1 SWEPCo 1.1 0.7 0.8 Sales and Purchases of Property Certain AEP subsidiaries had affiliated sales and purchases of electric property individually amounting to $100 thousand or more, sales and purchases of meters and transformers, and sales and purchases of transmission property. There were no gains or losses recorded on the transactions. The following tables show the sales and purchases, recorded at net book value: Sales Years Ended December 31, Company 2019 2018 2017 (in millions) AEP Texas $ 0.9 $ 0.3 $ 0.2 APCo 5.5 5.4 3.5 I&M 7.5 8.2 5.0 OPCo 7.0 10.7 2.9 PSO 0.8 1.0 1.5 SWEPCo 0.2 0.8 0.5 Purchases Years Ended December 31, Company 2019 2018 2017 (in millions) AEP Texas $ 0.3 $ 0.1 $ 0.4 AEPTCo 10.2 18.5 9.1 APCo 6.0 0.6 0.9 I&M 0.9 2.0 3.5 OPCo 3.0 2.8 1.6 PSO 0.5 1.3 0.2 SWEPCo 0.7 0.8 0.4 The amounts above are recorded in Property, Plant and Equipment on the balance sheets. Sempra Renewables LLC PPAs (Applies to I&M, OPCo and SWEPCo) In April 2019, AEP acquired Sempra Renewables LLC and its ownership interests in 724 MWs of wind generation. The operating wind generation portfolio includes seven wind farms. Prior to the acquisition, two wind farms had existing PPAs with I&M, OPCo and SWEPCo. See “Acquisitions” section of Note 7 for additional information. Intercompany Billings The Registrant Subsidiaries and other AEP subsidiaries perform certain utility services for each other when necessary or practical. The costs of these services are billed on a direct-charge basis, whenever possible, or on reasonable basis of proration for services that benefit multiple companies. The billings for services are made at cost and include no compensation for the use of equity capital. Charitable Contributions to AEP Foundation The American Electric Power Foundation is funded by American Electric Power and its utility operating units. The Foundation provides a permanent, ongoing resource for charitable initiatives and multi-year commitments in the communities served by AEP and initiatives outside of AEP’s 11-state service area. Charitable contributions to the AEP Foundation were recorded in Other Operation on the statements of income. The contributions recorded were as follows: Year Ended December 31, Company 2019 (in millions) AEP $ 50.0 AEP Texas 6.2 AEPTCo 6.5 APCo 8.9 I&M 9.0 OPCo 5.4 PSO 3.4 SWEPCo 5.5

Variable Interest Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2019
Variable Interest Entities	VARIABLE INTEREST ENTITIES AND EQUITY METHOD INVESTMENTS The disclosures in this note apply to all Registrants unless indicated otherwise. The accounting guidance for “Variable Interest Entities” is a consolidation model that considers if a company has a variable interest in a VIE. A VIE is a legal entity that possesses any of the following conditions: the entity’s equity at risk is not sufficient to permit the legal entity to finance its activities without additional subordinated financial support, equity owners are unable to direct the activities that most significantly impact the legal entity’s economic performance (or they possess disproportionate voting rights in relation to the economic interest in the legal entity), or the equity owners lack the obligation to absorb the legal entity’s expected losses or the right to receive the legal entity’s expected residual returns. Entities are required to consolidate a VIE when it is determined that they have a controlling financial interest in a VIE and therefore, are the primary beneficiary of that VIE, as defined by the accounting guidance for “Variable Interest Entities.” In determining whether AEP is the primary beneficiary of a VIE, management considers whether AEP has the power to direct the most significant activities of the VIE and is obligated to absorb losses or receive the expected residual returns that are significant to the VIE. Management believes that significant assumptions and judgments were applied consistently. AEP holds ownership interests in businesses with varying ownership structures. Partnership interests and other variable interests are evaluated to determine if each entity is a VIE, and if so, whether or not the VIE should be consolidated into AEP’s financial statements. AEP has not provided material financial or other support that was not previously contractually required to any of its consolidated VIEs. If an entity is determined not to be a VIE, or if the entity is determined to be a VIE and AEP is not deemed to be the primary beneficiary, the entity is accounted for under the equity method of accounting. Consolidated Variable Interests Entities (Applies to all Registrants except AEPTCo and PSO) Sabine Sabine is a mining operator providing mining services to SWEPCo. SWEPCo has no equity investment in Sabine but is Sabine’s only customer. SWEPCo guarantees the debt obligations and lease obligations of Sabine. Under the terms of the note agreements, substantially all assets are pledged and all rights under the lignite mining agreement are assigned to SWEPCo. The creditors of Sabine have no recourse to any AEP entity other than SWEPCo. Under the provisions of the mining agreement, SWEPCo is required to pay, as a part of the cost of lignite delivered, an amount equal to mining costs plus a management fee. In addition, SWEPCo determines how much coal will be mined each year. Based on these facts, management concluded that SWEPCo is the primary beneficiary and is required to consolidate Sabine. SWEPCo’s total billings from Sabine for the years ended December 31, 2019 , 2018 and 2017 were $110 million , $152 million and $137 million , respectively. See the tables below for the classification of Sabine’s assets and liabilities on SWEPCo’s balance sheets. As part of the process to receive a renewal of a Texas Railroad Commission permit for lignite mining, SWEPCo provides guarantees of mine reclamation of $155 million . Since SWEPCo uses self-bonding, the guarantee commits SWEPCo to complete the reclamation, in the event, Sabine does not complete the work. This guarantee ends upon depletion of reserves and completion of reclamation. The reserves are estimated to deplete in 2036 with reclamation completed by 2046 at an estimated cost of $107 million . Actual reclamation costs could vary due to inflation and scope changes to the mine reclamation. SWEPCo recovers these costs through its fuel clauses. As of December 31, 2019 , SWEPCo has recorded $83 million of mine reclamation costs in Asset Retirement Obligations and has collected $78 million through a rider for reclamation costs. The remaining $5 million is recorded in Deferred Charges and Other Noncurrent Assets on SWEPCo’s balance sheets. DCC Fuel I&M has nuclear fuel lease agreements with DCC Fuel, which was formed for the purpose of acquiring, owning and leasing nuclear fuel to I&M. DCC Fuel purchased the nuclear fuel from I&M with funds received from the issuance of notes to financial institutions. Each DCC Fuel entity is a single-lessee leasing arrangement with only one asset and is capitalized with all debt. Each is a separate legal entity from I&M, the assets of which are not available to satisfy the debts of I&M. Payments on the leases for the years ended December 31, 2019 , 2018 and 2017 were $95 million , $113 million and $136 million , respectively. The leases were recorded as finance leases on I&M’s balance sheets as title to the nuclear fuel transfers to I&M at the end of the respective lease terms, which do not exceed 54 months . Based on I&M’s control of DCC Fuel, management concluded that I&M is the primary beneficiary and is required to consolidate DCC Fuel. The finance leases are eliminated upon consolidation. See the tables below for the classification of DCC Fuel’s assets and liabilities on I&M’s balance sheets. Transition Funding Transition Funding was formed for the sole purpose of issuing and servicing securitization bonds related to Texas Restructuring Legislation. Management has concluded that AEP Texas is the primary beneficiary of Transition Funding because AEP Texas has the power to direct the most significant activities of the VIE and AEP Texas’ equity interest could potentially be significant. Therefore, AEP Texas is required to consolidate Transition Funding. The securitized bonds totaled $541 million and $791 million as of December 31, 2019 and 2018 , respectively, and are included in Long-term Debt Due Within One Year - Nonaffiliated and Long-term Debt - Nonaffiliated on the balance sheets. Transition Funding has securitized transition assets of $389 million and $637 million as of December 31, 2019 and 2018 , respectively, which are presented separately on the face of the balance sheets. The securitized transition assets represent the right to impose and collect Texas true-up costs from customers receiving electric transmission or distribution service from AEP Texas under recovery mechanisms approved by the PUCT. The securitization bonds are payable only from and secured by the securitized transition assets. The bondholders have no recourse to AEP Texas or any other AEP entity. AEP Texas acts as the servicer for Transition Funding’s securitized transition assets and remits all related amounts collected from customers to Transition Funding for interest and principal payments on the securitization bonds and related costs. See the tables below for the classification of Transition Funding’s assets and liabilities on the balance sheets. Restoration Funding Restoration Funding was formed for the sole purpose of issuing and servicing securitization bonds related to storm restoration of AEP Texas’ distribution system primarily due to damage caused by Hurricane Harvey. See “Texas Storm Cost Securitization” section of Note 4 for additional information. Management has concluded that AEP Texas is the primary beneficiary of Restoration Funding because AEP Texas has the power to direct the most significant activities of the VIE and AEP Texas’ equity interest could potentially be significant. Therefore, AEP Texas is required to consolidate Restoration Funding. The securitized bonds totaled $235 million as of December 31, 2019 and are included in Long-term Debt Due Within One Year - Nonaffiliated and Long-term Debt - Nonaffiliated on the balance sheets. Restoration Funding has securitized assets of $232 million as of December 31, 2019 which are presented separately on the face of the balance sheets. The securitized restoration assets represent the right to impose and collect Texas storm restoration costs from customers receiving electric transmission or distribution service from AEP Texas under recovery mechanisms approved by the PUCT. The securitization bonds are payable only from and secured by the securitized assets. The bondholders have no recourse to AEP Texas or any other AEP entity. AEP Texas acts as the servicer for Restoration Funding’s securitized assets and remits all related amounts collected from customers to Restoration Funding for interest and principal payments on the securitization bonds and related costs. See the table below for the classification of Restoration Funding’s assets and liabilities on the balance sheets. Ohio Phase-in-Recovery Funding Ohio Phase-in-Recovery Funding was formed for the sole purpose of issuing and servicing securitization bonds related to phase-in recovery property. In July 2019, the securitization bonds matured. Management has concluded that OPCo is the primary beneficiary of Ohio Phase-in-Recovery Funding because OPCo has the power to direct the most significant activities of the VIE and OPCo’s equity interest could potentially be significant. Therefore, OPCo is required to consolidate Ohio Phase-in-Recovery Funding. The securitized bonds totaled $0 and $48 million as of December 31, 2019 and 2018 , respectively, and are included in Long-term Debt Due Within One Year - Nonaffiliated on the balance sheets. Ohio Phase-in-Recovery Funding has securitized assets of $0 and $13 million as of December 31, 2019 and 2018 , respectively, which are presented separately on the face of the balance sheets. The phase-in recovery property represented the right to impose and collect Ohio deferred distribution charges from customers receiving electric transmission and distribution service from OPCo under a recovery mechanism approved by the PUCO. The securitization bonds were payable only from and secured by the securitized assets. The bondholders had no recourse to OPCo or any other AEP entity. OPCo acted as the servicer for Ohio Phase-in-Recovery Funding’s securitized assets and remitted all related amounts collected from customers to Ohio Phase-in-Recovery Funding for interest and principal payments on the securitization bonds and related costs. See the tables below for the classification of Ohio Phase-in-Recovery Funding’s assets and liabilities on OPCo’s balance sheets. Appalachian Consumer Rate Relief Funding Appalachian Consumer Rate Relief Funding was formed for the sole purpose of issuing and servicing securitization bonds related to APCo’s under-recovered ENEC deferral balance. Management has concluded that APCo is the primary beneficiary of Appalachian Consumer Rate Relief Funding because APCo has the power to direct the most significant activities of the VIE and APCo’s equity interest could potentially be significant. Therefore, APCo is required to consolidate Appalachian Consumer Rate Relief Funding. The securitized bonds totaled $223 million and $272 million as of December 31, 2019 and 2018 , respectively, and are included in Long-term Debt Due Within One Year - Nonaffiliated and Long-term Debt - Nonaffiliated on the balance sheets. Appalachian Consumer Rate Relief Funding has securitized assets of $235 million and $259 million as of December 31, 2019 and 2018 , respectively, which are presented separately on the face of the balance sheets. The phase-in recovery property represents the right to impose and collect West Virginia deferred generation charges from customers receiving electric transmission, distribution and generation service from APCo under a recovery mechanism approved by the WVPSC. In November 2013, securitization bonds were issued. The securitization bonds are payable only from and secured by the securitized assets. The bondholders have no recourse to APCo or any other AEP entity. APCo acts as the servicer for Appalachian Consumer Rate Relief Funding’s securitized assets and remits all related amounts collected from customers to Appalachian Consumer Rate Relief Funding for interest and principal payments on the securitization bonds and related costs. See the tables below for the classification of Appalachian Consumer Rate Relief Funding’s assets and liabilities on APCo’s balance sheets. AEP Credit AEP Credit is a wholly-owned subsidiary of Parent. AEP Credit purchases, without recourse, accounts receivable from certain utility subsidiaries of AEP to reduce working capital requirements. AEP provides a minimum of 5% equity and up to 20% of AEP Credit’s short-term borrowing needs in excess of third-party financings. Any third-party financing of AEP Credit only has recourse to the receivables securitized for such financing. Based on AEP’s control of AEP Credit, management concluded that AEP is the primary beneficiary and is required to consolidate AEP Credit. See the tables below for the classification of AEP Credit’s assets and liabilities on the balance sheets. See “Securitized Accounts Receivables - AEP Credit” section of Note 14 . EIS AEP’s subsidiaries participate in one protected cell of EIS for six lines of insurance. EIS has multiple protected cells. Neither AEP nor its subsidiaries have an equity investment in EIS. The AEP System is essentially this EIS cell’s only participant, but allows certain third-parties access to this insurance. AEP’s subsidiaries and any allowed third-parties share in the insurance coverage, premiums and risk of loss from claims. Based on AEP’s control and the structure of the protected cell of EIS, management concluded that AEP is the primary beneficiary of the protected cell and is required to consolidate the protected cell of EIS. The insurance premium expense to the protected cell for the years ended December 31, 2019 , 2018 and 2017 was $34 million , $34 million and $29 million , respectively. See the tables below for the classification of the protected cell’s assets and liabilities on the balance sheets. The amount reported as equity is the protected cell’s policy holders’ surplus. Transource Energy Transource Energy was formed for the purpose of investing in utilities which develop, acquire, construct, own and operate transmission facilities in accordance with FERC-approved rates. AEP has equity and voting ownership of 86.5% with the other owner having 13.5% interest. Management has concluded that Transource Energy is a VIE and that AEP is the primary beneficiary because AEP has the power to direct the most significant activities of the entity and AEP’s equity interest could potentially be significant. Therefore, AEP is required to consolidate Transource Energy. Transource Energy’s activities consist of the development, construction and operation of FERC-regulated transmission assets in Missouri, West Virginia, Pennsylvania and Maryland. Transource Energy has a credit facility agreement where borrowings are loaned through intercompany lending agreements to its subsidiaries. The creditor to the agreement has no recourse to the general credit of AEP. Transource Energy’s credit facility agreement contains certain covenants and require it to maintain a percentage of debt-to-total capitalization at a level that does not exceed 67.5% . For the years ended December 31, 2019 , 2018 and 2017 , AEP provided capital contributions to Transource Energy of $0 , $4 million and $5 million , respectively. See the tables below for the classification of Transource Energy’s assets and liabilities on the balance sheets. Desert Sky Wind Farm LLC and Trent Wind Farm LLC Desert Sky Wind Farm LLC and Trent Wind Farm LLC (collectively the LLCs) were established for the purpose of repowering, owning and operating wind-powered electric energy generation facilities in Texas. In January 2018, AEP admitted a nonaffiliate as a member of the LLCs to own and repower Desert Sky and Trent. The nonaffiliate contributed full turbine sets to each project in exchange for a 20.1% interest in the LLCs. The nonaffiliates’ contribution of $84 million was recorded as Net Property, Plant and Equipment on the balance sheets, which was the fair value as of the contribution date determined based on key input assumptions of the original cost of the full turbine sets and the discounted cash flow benefit associated with the production tax credits available from repowering Desert Sky and Trent based on their expected net capacity, capacity factor and the operational availability. AEP owns 79.9% of the LLCs. As a result, management has concluded that the LLCs are VIEs and that AEP is the primary beneficiary based on its power to direct the activities that most significantly impact their economic performance. Also in January 2018, the LLCs entered into a forward PPA for the sale of power to AEPEP related to deliveries of electricity beginning January 1, 2021 for a 12 year period. Prior to the effective date of the PPA, the LLCs will sell power at market rates into ERCOT. AEP and the nonaffiliate will share tax attributes including PTC and cash distributions from the operation of the LLCs generally consistent with the ownership percentages. See the tables below for the classification of the LLCs’ assets and liabilities on the balance sheets. AEP has a call right, which if exercised, would require the nonaffiliate to sell its noncontrolling interest in the LLCs to AEP. The call exercise period is for ninety days, beginning July 2020 for Trent Wind Farm LLC and August 2020 for Desert Sky Wind Farm LLC. The nonaffiliates’ interest in the LLCs is presented as Redeemable Noncontrolling Interest on the balance sheets. The nonaffiliate holds redemption rights, which if exercised, would require AEP to purchase the nonaffiliates’ noncontrolling interest in the LLCs. The redemption right exercise period is for ninety days, beginning July 2021 for Trent Wind Farm LLC and August 2021 for Desert Sky Wind Farm LLC. The exercise price for both the call and redemption right are determined using a discounted cash flow model with agreed input assumptions as well as potential updates to certain assumptions reasonably expected based on the actual results of the LLCs. As of December 31, 2019 and 2018 , AEP recorded $66 million and $69 million , respectively, of Redeemable Noncontrolling Interest in Mezzanine Equity on the balance sheets. Apple Blossom Wind Holdings LLC and Black Oak Getty Wind Holdings LLC In April 2019, AEP acquired an equity interest in Apple Blossom Wind Holdings LLC (Apple Blossom) and Black Oak Getty Wind Holdings LLC (Black Oak) (collectively the Project Entities) as part of the purchase of Sempra Renewables LLC. Both of the Project Entities have long-term PPAs for 100% of their energy production. The Project Entities are tax equity partnerships with nonaffiliated noncontrolling interests to which a percentage of earnings, tax attributes and cash flows are allocated in accordance with the respective limited liability company agreements. Management has concluded that the Project Entities are VIEs and that AEP is the primary beneficiary based on its power as managing member to direct the activities that most significantly impact the Project Entities’ economic performance. In addition, AEP has not provided material financial or other support to the Project Entities that was not previously contractually required. As the primary beneficiary of the Project Entities, AEP consolidates the Project Entities into its financial statements. See the table below for the classification of Project Entities’ assets and liabilities on the balance sheets. The nonaffiliated interests in the Project Entities is presented in Noncontrolling Interests on the balance sheets. As of December 31, 2019 , AEP recorded $128 million of Noncontrolling Interests related to the Project Entities in Equity on the balance sheets. The Project Entities’ tax equity partnerships represent substantive profit-sharing arrangements. The method for attributing income and loss to the noncontrolling interests is a balance sheet approach referred to as the hypothetical liquidation at book value (HLBV) method. Under the HLBV method, the income and loss attributable to the noncontrolling interests reflect changes in the amounts the members would hypothetically receive at each balance sheet date under the liquidation provisions of the respective limited liability company agreements, assuming the net assets of these entities were liquidated at recorded amounts, after taking into account any capital transactions, such as contributions or distributions, between the entities and the members. For the year ended December 31, 2019 , the HLBV method resulted in a loss of $6 million allocated to Noncontrolling Interests. Santa Rita East In July 2019, AEP acquired a 75% interest in Santa Rita East Wind Energy Holdings, LLC and its wholly-owned subsidiary, Santa Rita East Wind Energy, LLC (collectively, Santa Rita East). Santa Rita East is a partnership whose sole purpose is to own and operate a 302 MW wind generation facility in west Texas. Santa Rita East delivers energy and provides renewable energy credits through three long-term PPAs totaling 260 MWs. The remaining 42 MWs of energy are sold at wholesale into ERCOT. Management has concluded that Santa Rita East is a VIE and that AEP is the primary beneficiary based on its power as managing member of the partnership to direct the activities that most significantly impact Santa Rita East’s economic performance. As the primary beneficiary of Santa Rita East, AEP consolidates Santa Rita East into its financial statements. See the table below for the classification of Santa Rita East’s assets and liabilities on the balance sheets. AEP recognized $10 million of PTC attributable to Santa Rita East for the year ended December 31, 2019 which was recorded in Income Tax Expense (Benefit) on the statements of income. The nonaffiliated interest in Santa Rita East is presented in Noncontrolling Interests on the balance sheets. As of December 31, 2019 , AEP recorded $118 million of Noncontrolling Interests related to Santa Rita East in Equity on the balance sheets. The balances below represent the assets and liabilities of the VIEs that are consolidated. These balances include intercompany transactions that are eliminated upon consolidation. American Electric Power Company, Inc. and Subsidiary Companies Variable Interest Entities December 31, 2019 Registrant Subsidiaries SWEPCo Sabine I&M DCC Fuel AEP Texas Transition Funding AEP Texas Restoration Funding OPCo APCo (in millions) ASSETS Current Assets $ 80.0 $ 86.5 $ 187.0 $ 9.4 $ — $ 21.5 Net Property, Plant and Equipment 111.6 156.8 — — — — Other Noncurrent Assets 93.2 82.5 428.1 (a) 234.4 (b) — 237.5 (c) Total Assets $ 284.8 $ 325.8 $ 615.1 $ 243.8 $ — $ 259.0 LIABILITIES AND EQUITY Current Liabilities $ 50.6 $ 86.4 $ 280.2 $ 16.3 $ — $ 28.3 Noncurrent Liabilities 233.6 239.4 316.3 226.3 — 228.8 Equity 0.6 — 18.6 1.2 — 1.9 Total Liabilities and Equity $ 284.8 $ 325.8 $ 615.1 $ 243.8 $ — $ 259.0 (a) Includes an intercompany item eliminated in consolidation of $39 million . (b) Includes an intercompany item eliminated in consolidation of $1 million . (c) Includes an intercompany item eliminated in consolidation of $3 million . American Electric Power Company, Inc. and Subsidiary Companies Variable Interest Entities December 31, 2019 Other Consolidated VIEs AEP Credit Protected Cell of EIS Transource Energy Desert Sky and Trent Apple Blossom and Black Oak Santa Rita East (in millions) ASSETS Current Assets $ 842.8 $ 194.6 $ 25.8 $ 7.8 $ 10.1 $ 17.7 Net Property, Plant and Equipment — — 424.1 330.6 231.4 465.2 Other Noncurrent Assets 7.1 — 3.2 10.1 13.1 0.3 Total Assets $ 849.9 $ 194.6 $ 453.1 $ 348.5 $ 254.6 $ 483.2 LIABILITIES AND EQUITY Current Liabilities $ 805.2 $ 40.7 $ 192.4 $ 5.5 $ 5.4 $ 3.9 Noncurrent Liabilities 0.9 78.0 4.8 15.8 4.7 7.5 Equity 43.8 75.9 255.9 327.2 244.5 471.8 Total Liabilities and Equity $ 849.9 $ 194.6 $ 453.1 $ 348.5 $ 254.6 $ 483.2 American Electric Power Company, Inc. and Subsidiary Companies Variable Interest Entities December 31, 2018 Registrant Subsidiaries SWEPCo Sabine I&M DCC Fuel AEP Texas Transition Funding OPCo APCo (in millions) ASSETS Current Assets $ 70.0 $ 77.6 $ 192.8 $ 29.5 $ 24.8 Net Property, Plant and Equipment 106.9 122.3 — — — Other Noncurrent Assets 98.5 58.4 683.5 (a) 24.2 (b) 261.8 (c) Total Assets $ 275.4 $ 258.3 $ 876.3 $ 53.7 $ 286.6 LIABILITIES AND EQUITY Current Liabilities $ 31.1 $ 77.1 $ 271.9 $ 48.5 $ 28.0 Noncurrent Liabilities 244.0 181.2 586.1 3.9 256.7 Equity 0.3 — 18.3 1.3 1.9 Total Liabilities and Equity $ 275.4 $ 258.3 $ 876.3 $ 53.7 $ 286.6 (a) Includes an intercompany item eliminated in consolidation of $47 million . (b) Includes an intercompany item eliminated in consolidation of $11 million . (c) Includes an intercompany item eliminated in consolidation of $3 million . American Electric Power Company, Inc. and Subsidiary Companies Variable Interest Entities December 31, 2018 Other Consolidated VIEs AEP Credit Protected Cell of EIS Transource Energy Desert Sky and Trent (in millions) ASSETS Current Assets $ 974.2 $ 177.8 $ 25.7 $ 6.8 Net Property, Plant and Equipment — — 380.3 348.5 Other Noncurrent Assets 6.3 0.1 1.9 — Total Assets $ 980.5 $ 177.9 $ 407.9 $ 355.3 LIABILITIES AND EQUITY Current Liabilities $ 923.5 $ 38.6 $ 19.9 $ 8.7 Noncurrent Liabilities 0.8 85.3 160.3 6.2 Equity 56.2 54.0 227.7 340.4 Total Liabilities and Equity $ 980.5 $ 177.9 $ 407.9 $ 355.3 Non-Consolidated Significant Variable Interests DHLC DHLC is a mining operator which sells 50% of the lignite produced to SWEPCo and 50% to CLECO. The operations of DHLC are governed by the lignite mining agreement among SWEPCo, CLECO and DHLC. SWEPCo and CLECO share the executive board seats and voting rights equally. In accordance with the lignite mining agreement, each entity is responsible for 50% of DHLC’s obligations, including debt. SWEPCo and CLECO equally approve DHLC’s annual budget. The creditors of DHLC have no recourse to any AEP entity other than SWEPCo. As SWEPCo is the sole equity owner of DHLC, it receives 100% of the management fee. SWEPCo’s total billings from DHLC for the years ended December 31, 2019 , 2018 and 2017 were $55 million , $58 million and $61 million , respectively. SWEPCo is not required to consolidate DHLC as it is not the primary beneficiary, although SWEPCo holds a significant variable interest in DHLC. SWEPCo’s equity investment in DHLC is included in Deferred Charges and Other Noncurrent Assets on SWEPCo’s balance sheets. SWEPCo’s investment in DHLC was: December 31, 2019 2018 As Reported on the Balance Sheet Maximum Exposure As Reported on the Balance Sheet Maximum Exposure (in millions) Capital Contribution from SWEPCo $ 7.6 $ 7.6 $ 7.6 $ 7.6 Retained Earnings 17.5 17.5 14.5 14.5 SWEPCo’s Share of Obligations — 130.0 — 167.6 Total Investment in DHLC $ 25.1 $ 155.1 $ 22.1 $ 189.7 OVEC AEP and several nonaffiliated utility companies jointly own OVEC. As of December 31, 2019 , AEP’s ownership in OVEC was 43.47% . Parent owns 39.17% and OPCo owns 4.3% . APCo, I&M and OPCo are members to an intercompany power agreement. The Registrants’ power participation ratios are 15.69% for APCo, 7.85% for I&M and 19.93% for OPCo. Participants of this agreement are entitled to receive and are obligated to pay for all OVEC generating capacity, approximately 2,400 MWs, in proportion to their respective power participation ratios. The proceeds from the sale of power by OVEC are designed to be sufficient for OVEC to meet its operating expenses and fixed costs, including outstanding indebtedness, and provide a return on capital. The intercompany power agreement ends in June 2040 . AEP and other nonaffiliated owners authorized environmental investments related to their ownership interests. OVEC financed capital expenditures in connection with the engineering and construction of FGD projects and the associated waste disposal landfills at its two generation plants. These environmental projects were funded through debt issuances. As of December 31, 2019 and 2018 , OVEC’s outstanding indebtedness was approximately $1.4 billion and $1.4 billion , respectively. Although they are not an obligor or guarantor, the Registrants’ are responsible for their respective ratio of OVEC’s outstanding debt through the intercompany power agreement. Principal and interest payments related to OVEC’s outstanding indebtedness are disclosed in accordance with the accounting guidance for “Commitments.” See the “Commitments” section of Note 6 for additional information. AEP is not required to consolidate OVEC as it is not the primary beneficiary, although AEP and its subsidiary holds a significant variable interest in OVEC. Power to control decision making that significantly impacts the economic performance of OVEC is shared amongst the owners through their representation on the Board of Directors of OVEC and the representation of the sponsoring companies on the Operating Committee under the intercompany power agreement. AEP’s investment in OVEC was: December 31, 2019 2018 As Reported on the Balance Sheet Maximum Exposure As Reported on Maximum Exposure (in millions) Capital Contribution from AEP $ 4.4 $ 4.4 $ 4.4 $ 4.4 AEP’s Ratio of OVEC Debt (a) — 588.9 — 604.1 Total Investment in OVEC $ 4.4 $ 593.3 $ 4.4 $ 608.5 (a) Based on the Registrants’ power participation ratios APCo, I&M and OPCo’s share of OVEC debt was $213 million , $106 million and $270 million as of December 31, 2019 and $218 million , $109 million and $277 million as of December 31, 2018 , respectively. Power purchased by the Registrant Subsidiaries from OVEC is included in Purchased Electricity for Resale on the statements of income and is shown in the table below: Years Ended December 31, Company 2019 2018 2017 (in millions) APCo $ 104.5 $ 100.4 $ 101.0 I&M 52.3 50.2 50.5 OPCo 132.7 127.5 128.2 Potomac-Appalachian Transmission Highline, LLC (PATH) AEP and FirstEnergy Corp. (FirstEnergy) have a joint venture in PATH. PATH is a series limited liability company and was created to construct, through its operating companies, a high-voltage transmission line project in the PJM region. PATH consists of the “West Virginia Series (PATH-WV),” owned equally by subsidiaries of FirstEnergy and AEP, and the “Allegheny Series” which is 100% owned by a subsidiary of FirstEnergy. Provisions exist within the PATH-WV agreement that make it a VIE. AEP has no interest or control in the “Allegheny Series.” AEP is not required to consolidate PATH-WV as AEP is not the primary beneficiary, although AEP holds a significant variable interest in PATH-WV. AEP’s equity investment in PATH-WV is included in Deferred Charges and Other Noncurrent Assets on the balance sheets. AEP and FirstEnergy share the returns and losses equally in PATH-WV. AEP’s subsidiaries and FirstEnergy’s subsidiaries provide services to the PATH companies through service agreements. The entities recover costs through regulated rates. In August 2012, the PJM board cancelled the PATH Project, the transmission project that PATH was intended to develop and removed it from the 2012 Regional Transmission Expansion Plan. In September 2012, the PATH Project companies submitted an application to the FERC requesting authority to recover prudently-incurred costs associated with the PATH Project. In November 2012, the FERC issued an order accepting the PATH Project’s abandonment cost recovery application, subject to settlement procedures and hearing. The parties to the case were unable to reach a settlement agreement and in March 2014, settlement judge procedures were terminated. Hearings at the FERC were held in March and April 2015. In April 2015, PATH filed a stipulation agreement with the FERC that agreed to a 50% debt and 50% equity capital structure and a 4.7% cost of long-term debt for the entire amortization period. In September 2015, the ALJ issued an advisory Initial Decision. Additional briefing was submitted during the fourth quarter of 2015. In January 2017, the FERC issued its order on Initial Decision, adopting in part and rejecting in part the ALJ’s recommendations. The FERC order included (a) a finding that the PATH Project’s abandonment costs were prudently incurred, (b) a finding that the disposition of certain assets was prudent, (c) guidance regarding the future disposition of assets, (d) a reduction of PATH WV’s authorized ROE to 8.11% prospectively only after the date of the order, (e) an adjustment of the amortization period to end December 2017, and (f) a credit for certain amounts that were deemed to be not includable in PATH-WV’s formula rates. In February 2017, the PATH Companies filed a

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2019
Property, Plant and Equipment	PROPERTY, PLANT AND EQUIPMENT The disclosures in this note apply to all Registrants unless indicated otherwise. Property, Plant and Equipment is shown functionally on the face of the balance sheets. The following tables include the total plant balances as of December 31, 2019 and 2018 : December 31, 2019 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Regulated Property, Plant and Equipment Generation $ 21,323.5 (a) $ — $ — $ 6,563.7 $ 5,099.7 $ — $ 1,574.6 $ 4,691.4 (a) Transmission 24,763.4 4,466.5 8,137.9 3,584.1 1,641.8 2,686.3 948.5 2,056.5 Distribution 22,440.8 4,215.2 — 4,201.7 2,437.6 5,323.5 2,684.8 2,270.7 Other 4,369.6 803.4 268.2 542.0 590.9 754.7 337.2 520.6 CWIP 4,261.2 (a) 763.9 1,485.7 593.4 382.3 394.4 133.4 210.1 (a) Less: Accumulated Depreciation 18,778.1 1,465.0 402.3 4,425.6 3,281.4 2,261.7 1,579.9 2,766.2 Total Regulated Property, Plant and Equipment - Net 58,380.4 8,784.0 9,489.5 11,059.3 6,870.9 6,897.2 4,098.6 6,983.1 Nonregulated Property, Plant and Equipment - Net 1,757.7 61.1 1.4 22.6 28.8 9.8 4.7 112.1 Total Property, Plant and Equipment - Net $ 60,138.1 $ 8,845.1 $ 9,490.9 $ 11,081.9 $ 6,899.7 $ 6,907.0 $ 4,103.3 $ 7,095.2 December 31, 2018 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Regulated Property, Plant and Equipment Generation $ 20,989.1 (a) $ — $ — $ 6,509.6 $ 4,887.2 $ — $ 1,577.0 $ 4,672.6 (a) Transmission 21,500.5 3,683.6 6,515.8 3,317.7 1,576.8 2,544.3 892.3 1,866.9 Distribution 21,192.8 4,043.2 — 3,989.4 2,249.7 4,942.3 2,572.8 2,178.6 Other 3,770.8 724.6 172.6 457.4 543.1 563.7 298.1 485.2 CWIP 4,352.6 (a) 836.0 1,578.3 490.2 465.3 432.1 94.0 194.7 (a) Less: Accumulated Depreciation 17,743.1 1,431.2 271.9 4,118.9 3,139.4 2,217.7 1,472.1 2,633.5 Total Regulated Property, Plant and Equipment - Net 54,062.7 7,856.2 7,994.8 10,645.4 6,582.7 6,264.7 3,962.1 6,764.5 Nonregulated Property, Plant and Equipment - Net 1,036.4 135.6 1.4 22.9 28.5 10.2 4.6 107.3 Total Property, Plant and Equipment - Net $ 55,099.1 $ 7,991.8 $ 7,996.2 $ 10,668.3 $ 6,611.2 $ 6,274.9 $ 3,966.7 $ 6,871.8 (a) AEP and SWEPCo’s regulated generation and regulated CWIP include amounts related to SWEPCo’s Arkansas jurisdictional share of the Turk Plant. Depreciation, Depletion and Amortization The Registrants provide for depreciation of Property, Plant and Equipment, excluding coal-mining properties, on a straight-line basis over the estimated useful lives of property, generally using composite rates by functional class. The following tables provide total regulated annual composite depreciation rates and depreciable lives for the Registrants: AEP 2019 2018 2017 Functional Class of Property Annual Composite Depreciation Rate Ranges Depreciable Life Ranges Annual Composite Depreciation Rate Ranges Depreciable Life Ranges Annual Composite Depreciation Rate Ranges Depreciable Life Ranges (in years) (in years) (in years) Generation 2.5% - 5.5% 20 - 132 2.4% - 4.0% 20 - 132 2.3% - 3.7% 20 - 132 Transmission 1.8% - 2.6% 15 - 81 1.6% - 2.7% 15 - 81 1.6% - 2.7% 15 - 100 Distribution 2.7% - 3.7% 7 - 78 2.7% - 3.6% 7 - 78 2.7% - 3.7% 5 - 156 Other 2.6% - 9.5% 5 - 75 2.3% - 9.8% 5 - 75 2.3% - 9.2% 5 - 84 AEP Texas 2019 2018 2017 Functional Class of Property Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges (in years) (in years) (in years) Transmission 1.8% 45 - 81 1.7% 45 - 81 1.7% 45 - 81 Distribution 3.5% 7 - 70 3.6% 7 - 70 3.6% 7 - 70 Other 6.3% 5 - 50 6.0% 5 - 50 8.7% 5 - 50 AEPTCo 2019 2018 2017 Functional Class of Property Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges (in years) (in years) (in years) Transmission 2.0% 24 - 75 1.9% 20 - 75 1.7% 20 - 100 Other 5.8% 5 - 64 5.6% 5 - 64 6.7% 5 - 84 APCo 2019 2018 2017 Functional Class of Property Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges (in years) (in years) (in years) Generation 3.2% 35 - 118 3.1% 35 - 112 3.1% 35 - 112 Transmission 1.8% 15 - 71 1.6% 15 - 68 1.6% 15 - 68 Distribution 3.7% 12 - 57 3.6% 10 - 57 3.7% 10 - 57 Other 7.2% 5 - 55 7.4% 5 - 55 6.5% 5 - 55 I&M 2019 2018 2017 Functional Class of Property Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges (in years) (in years) (in years) Generation 4.0% 20 - 132 3.4% 20 - 132 2.4% 20 - 132 Transmission 1.9% 50 - 73 1.8% 50 - 73 1.7% 50 - 75 Distribution 3.4% 9 - 75 3.1% 9 - 75 2.7% 10 - 70 Other 9.4% 5 - 50 8.9% 5 - 50 8.4% 5 - 45 OPCo 2019 2018 2017 Functional Class of Property Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges (in years) (in years) (in years) Transmission 2.3% 39 - 60 2.3% 39 - 60 2.3% 39 - 60 Distribution 3.1% 14 - 65 3.0% 14 - 65 2.8% 5 - 57 Other 4.9% 5 - 50 6.3% 5 - 50 6.2% 5 - 50 PSO 2019 2018 2017 Functional Class of Property Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges (in years) (in years) (in years) Generation 2.9% 35 - 75 2.9% 35 - 75 2.4% 35 - 85 Transmission 2.4% 45 - 75 2.3% 45 - 75 2.2% 45 - 100 Distribution 2.9% 15 - 78 2.9% 15 - 78 2.7% 27 - 156 Other 5.6% 5 - 64 6.3% 5 - 64 7.4% 5 - 84 SWEPCo 2019 2018 2017 Functional Class of Property Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges (in years) (in years) (in years) Generation 2.5% 40 - 70 2.4% 40 - 70 2.3% 40 - 70 Transmission 2.4% 50 - 73 2.2% 50 - 73 2.3% 50 - 73 Distribution 2.7% 25 - 70 2.7% 25 - 70 2.7% 25 - 70 Other 7.6% 5 - 55 8.0% 5 - 55 7.2% 5 - 55 The following table includes the nonregulated annual composite depreciation rate ranges and nonregulated depreciable life ranges for AEP and AEP Texas. Depreciation rate ranges and depreciable life ranges are not meaningful for nonregulated property of AEPTCo, APCo, I&M, OPCo, PSO and SWEPCo for 2019 , 2018 and 2017 . 2019 2018 2017 Functional Class of Property Annual Composite Depreciation Rate Ranges Depreciable Life Ranges Annual Composite Depreciation Rate Ranges Depreciable Life Ranges Annual Composite Depreciation Rate Ranges Depreciable Life Ranges (in years) (in years) (in years) Generation 3.2% - 21.2% 15 - 59 3.4% - 22.3% 15 - 59 2.4% - 5.1% 15 - 66 Transmission 2.5% 30 - 40 2.4% 40 0.2% 40 Distribution 2.3% 40 2.3% 40 2.3% 40 Other 17.6% 5 - 50 (a) 16.3% 5 - 50 (a) 12.1% 5 - 50 (a) (a) SWEPCo’s nonregulated property, plant and equipment is depreciated using the straight-line method over a range of 3 to 20 years. SWEPCo provides for depreciation, depletion and amortization of coal-mining assets over each asset’s estimated useful life or the estimated life of each mine, whichever is shorter, using the straight-line method for mining structures and equipment. SWEPCo uses either the straight-line method or the units-of-production method to amortize mine development costs and deplete coal rights based on estimated recoverable tonnages. SWEPCo includes these costs in fuel expense. For regulated operations, the composite depreciation rate generally includes a component for non-ARO removal costs, which is credited to Accumulated Depreciation and Amortization on the balance sheets. Actual removal costs incurred are charged to Accumulated Depreciation and Amortization. Any excess of accrued non-ARO removal costs over actual removal costs incurred is reclassified from Accumulated Depreciation and Amortization and reflected as a regulatory liability. For nonregulated operations, non-ARO removal costs are expensed as incurred. Asset Retirement Obligations (Applies to all Registrants except AEPTCo) The Registrants record ARO in accordance with the accounting guidance for “Asset Retirement and Environmental Obligations” for legal obligations for asbestos removal and for the retirement of certain ash disposal facilities, wind farms, solar farms and certain coal mining facilities. I&M records ARO for the decommissioning of the Cook Plant. The Registrants have identified, but not recognized, ARO liabilities related to electric transmission and distribution assets as a result of certain easements on property on which assets are owned. Generally, such easements are perpetual and require only the retirement and removal of assets upon the cessation of the property’s use. The retirement obligation is not estimable for such easements since the Registrants plan to use their facilities indefinitely. The retirement obligation would only be recognized if and when the Registrants abandon or cease the use of specific easements, which is not expected. As of December 31, 2019 and 2018 , I&M’s ARO liability for nuclear decommissioning of the Cook Plant was $1.73 billion and $1.66 billion , respectively. These liabilities are reflected in Asset Retirement Obligations on I&M’s balance sheets. As of December 31, 2019 and 2018 , the fair value of I&M’s assets that are legally restricted for purposes of settling decommissioning liabilities totaled $2.65 billion and $2.16 billion , respectively. These assets are included in Spent Nuclear Fuel and Decommissioning Trusts on I&M’s balance sheets. The following is a reconciliation of the 2019 and 2018 aggregate carrying amounts of ARO by Registrant: Company ARO as of December 31, 2018 Accretion Expense Liabilities Incurred Liabilities Settled Revisions in Cash Flow Estimates (a) ARO as of December 31, 2019 (in millions) AEP (b)(c)(d)(e) $ 2,355.5 $ 102.5 $ 12.0 $ (118.1 ) $ 67.0 $ 2,418.9 AEP Texas (b)(e) 27.9 1.3 — (0.2 ) 0.1 29.1 APCo (b)(e) 116.1 5.9 — (17.6 ) 6.7 111.1 I&M (b)(c)(e) 1,681.3 67.4 — (0.2 ) 0.1 1,748.6 OPCo (e) 1.8 0.1 — (0.3 ) 0.2 1.8 PSO (b)(e) 46.9 3.1 — (0.4 ) 2.6 52.2 SWEPCo (b)(d)(e) 206.8 10.3 — (11.8 ) 6.9 212.2 Company ARO as of December 31, 2017 Accretion Expense Liabilities Incurred Liabilities Settled Revisions in Cash Flow Estimates (a) ARO as of December 31, 2018 (in millions) AEP (b)(c)(d)(e) $ 2,005.7 $ 93.7 $ 0.8 $ (87.0 ) $ 342.3 (f) $ 2,355.5 AEP Texas (b)(e) 26.7 1.2 — (0.1 ) 0.1 27.9 APCo (b)(e) 125.0 6.6 — (17.3 ) 1.8 116.1 I&M (b)(c)(e) 1,321.8 58.7 — (0.2 ) 301.0 (f) 1,681.3 OPCo (e) 1.7 0.1 — — — 1.8 PSO (b)(e) 54.0 3.2 — (0.4 ) (9.9 ) 46.9 SWEPCo (b)(d)(e) 169.2 9.1 0.2 (11.7 ) 40.0 206.8 (a) Primarily related to ash ponds, landfills and mine reclamation, generally due to changes in estimated closure area, volumes and/or unit costs. (b) Includes ARO related to ash disposal facilities. (c) Includes ARO related to nuclear decommissioning costs for the Cook Plant of $1.73 billion and $1.66 billion as of December 31, 2019 and 2018 , respectively. (d) Includes ARO related to Sabine and DHLC. (e) Includes ARO related to asbestos removal. (f) Revision for Cook Plant related to a new third-party study, which impacted the ARO liability for changes of estimated cash flows and application of a new discount rate. Allowance for Funds Used During Construction and Interest Capitalization The Registrants’ amounts of Allowance for Equity Funds Used During Construction are summarized in the following table: Years Ended December 31, Company 2019 2018 2017 (in millions) AEP $ 168.4 $ 132.5 $ 93.7 AEP Texas 15.2 20.0 6.8 AEPTCo 84.3 70.6 49.0 APCo 16.6 13.2 9.2 I&M 19.4 11.9 11.1 OPCo 18.2 9.8 6.4 PSO 2.7 0.4 0.5 SWEPCo 6.8 6.0 2.4 The Registrants’ amounts of allowance for borrowed funds used during construction, including capitalized interest, are summarized in the following table: Years Ended December 31, Company 2019 2018 2017 (in millions) AEP $ 88.7 $ 73.6 $ 48.6 AEP Texas 20.0 18.4 6.8 AEPTCo 32.2 26.1 20.2 APCo 9.3 8.4 5.3 I&M 8.9 7.4 6.7 OPCo 6.7 5.8 3.8 PSO 1.9 0.9 1.1 SWEPCo 4.0 4.8 2.1 Jointly-owned Electric Facilities (Applies to AEP, AEP Texas, I&M, PSO and SWEPCo) The Registrants have electric facilities that are jointly-owned with affiliated and nonaffiliated companies. Using its own financing, each participating company is obligated to pay its share of the costs of these jointly-owned facilities in the same proportion as its ownership interest. Each Registrant’s proportionate share of the operating costs associated with these facilities is included in its statements of income and the investments and accumulated depreciation are reflected in its balance sheets under Property, Plant and Equipment as follows: Registrant’s Share as of December 31, 2019 Fuel Type Percent of Ownership Utility Plant in Service Construction Work in Progress Accumulated Depreciation (in millions) AEP Conesville Generating Station, Unit 4 (a)(h) Coal 83.5 % $ — $ — $ — Dolet Hills Power Station, Unit 1 (f) Lignite 40.2 % 337.3 6.2 216.5 Flint Creek Generating Station, Unit 1 (g) Coal 50.0 % 374.3 3.4 101.1 Pirkey Generating Station, Unit 1 (g) Lignite 85.9 % 607.8 7.7 416.8 Oklaunion Power Station (e) Coal 70.3 % 106.6 0.1 91.7 Turk Generating Plant (g) Coal 73.3 % 1,593.3 1.7 225.8 Total $ 3,019.3 $ 19.1 $ 1,051.9 AEP Texas Oklaunion Power Station (e) Coal 54.7 % $ 351.7 $ — $ 291.9 I&M Rockport Generating Plant (b)(c)(d) Coal 50.0 % $ 1,114.2 $ 105.5 $ 586.2 PSO Oklaunion Power Station (e) Coal 15.6 % $ 106.6 $ 0.1 $ 91.7 SWEPCo Dolet Hills Power Station, Unit 1 (f) Lignite 40.2 % $ 337.3 $ 6.2 $ 216.5 Flint Creek Generating Station, Unit 1 (g) Coal 50.0 % 374.3 3.4 101.1 Pirkey Generating Station, Unit 1 (g) Lignite 85.9 % 607.8 7.7 416.8 Turk Generating Plant (g) Coal 73.3 % 1,593.3 1.7 225.8 Total $ 2,912.7 $ 19.0 $ 960.2 Registrant’s Share as of December 31, 2018 Fuel Type Percent of Ownership Utility Plant in Service Construction Work in Progress Accumulated Depreciation (in millions) AEP Conesville Generating Station, Unit 4 (a)(h) Coal 83.5 % $ 16.4 $ 0.2 $ 2.4 Dolet Hills Power Station, Unit 1 (f) Lignite 40.2 % 336.2 5.1 209.6 Flint Creek Generating Station, Unit 1 (g) Coal 50.0 % 375.1 1.6 88.9 Pirkey Generating Station, Unit 1 (g) Lignite 85.9 % 591.3 16.6 418.0 Oklaunion Power Station (e) Coal 70.3 % 106.4 — 67.8 Turk Generating Plant (g) Coal 73.3 % 1,590.5 1.1 197.5 Total $ 3,015.9 $ 24.6 $ 984.2 AEP Texas Oklaunion Power Station (e) Coal 54.7 % $ 352.1 $ 0.2 $ 218.6 I&M Rockport Generating Plant (b)(c)(d) Coal 50.0 % $ 1,108.7 $ 50.2 $ 514.1 PSO Oklaunion Power Station (e) Coal 15.6 % $ 106.4 $ — $ 67.8 SWEPCo Dolet Hills Power Station, Unit 1 (f) Lignite 40.2 % $ 336.2 $ 5.1 $ 209.6 Flint Creek Generating Station, Unit 1 (g) Coal 50.0 % 375.1 1.6 88.9 Pirkey Generating Station, Unit 1 (g) Lignite 85.9 % 591.3 16.6 418.0 Turk Generating Plant (g) Coal 73.3 % 1,590.5 1.1 197.5 Total $ 2,893.1 $ 24.4 $ 914.0 (a) Operated by AGR. (b) Operated by I&M. (c) Amounts include I&M’s 50% ownership of both Unit 1 and capital additions for Unit 2. Unit 2 is subject to an operating lease with a nonaffiliated company. See the “Rockport Lease” section of Note 13 . (d) AEGCo owns 50% of Unit 1 with I&M and 50% of capital additions for Unit 2. (e) Operated by PSO, which owns 15.6% . Also jointly-owned ( 54.7% ) by AEP Texas and various nonaffiliated companies. (f) Operated by CLECO, a nonaffiliated company. (g) Operated by SWEPCo. (h) Conesville Generating Station, Unit 4 was impaired as of December 31, 2019. See the “Impairments” section of Note 7

Goodwill

Goodwill	12 Months Ended
	Dec. 31, 2019
Goodwill	GOODWILL The disclosure in this note applies to AEP only. The changes in AEP’s carrying amount of goodwill for the years ended December 31, 2019 and 2018 by operating segment are as follows: Corporate and Other Generation & Marketing AEP Consolidated (in millions) Balance as of December 31, 2017 $ 37.1 $ 15.4 $ 52.5 Impairment Losses — — — Balance as of December 31, 2018 37.1 15.4 52.5 Impairment Losses — — — Balance as of December 31, 2019 $ 37.1 $ 15.4 $ 52.5 In the fourth quarters of 2019 and 2018 , annual impairment tests were performed. The fair values of the reporting units with goodwill were estimated using cash flow projections and other market value indicators. There were no goodwill impairment losses. AEP does not have any accumulated impairment on existing goodwill.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	12 Months Ended
	Dec. 31, 2019
Revenue from Contracts with Customers	REVENUE FROM CONTRACTS WITH CUSTOMERS The disclosures in this note apply to all Registrants, unless indicated otherwise. Disaggregated Revenues from Contracts with Customers The table below represents AEP’s reportable segment revenues from contracts with customers, net of respective provisions for refund, by type of revenue: Year Ended December 31, 2019 Vertically Integrated Utilities Transmission and Distribution Utilities AEP Transmission Holdco Generation & Marketing Corporate and Other Reconciling Adjustments AEP Consolidated (in millions) Retail Revenues: Residential Revenues $ 3,643.7 $ 2,069.9 $ — $ — $ — $ — $ 5,713.6 Commercial Revenues 2,155.3 1,152.9 — — — — 3,308.2 Industrial Revenues 2,179.0 429.1 — — — (0.9 ) 2,607.2 Other Retail Revenues 179.1 43.8 — — — — 222.9 Total Retail Revenues 8,157.1 3,695.7 — — — (0.9 ) 11,851.9 Wholesale and Competitive Retail Revenues: Generation Revenues (b) 807.6 — — 254.8 — — 1,062.4 Transmission Revenues (a) 292.1 435.1 1,077.2 — — (825.0 ) 979.4 Renewable Generation Revenues (c) — — — 57.3 — — 57.3 Retail, Trading and Marketing Revenues (b) — — — 1,480.7 — (135.6 ) 1,345.1 Total Wholesale and Competitive Retail Revenues 1,099.7 435.1 1,077.2 1,792.8 — (960.6 ) 3,444.2 Other Revenues from Contracts with Customers (c) 168.2 169.4 16.6 4.9 104.7 (147.1 ) 316.7 Total Revenues from Contracts with Customers 9,425.0 4,300.2 1,093.8 1,797.7 104.7 (1,108.6 ) 15,612.8 Other Revenues: Alternative Revenues (c) (57.9 ) 32.3 (20.6 ) — — (66.9 ) (113.1 ) Other Revenues (c) — 150.0 — 59.9 (8.9 ) (139.3 ) 61.7 Total Other Revenues (57.9 ) 182.3 (20.6 ) 59.9 (8.9 ) (206.2 ) (51.4 ) Total Revenues $ 9,367.1 $ 4,482.5 $ 1,073.2 $ 1,857.6 $ 95.8 $ (1,314.8 ) $ 15,561.4 (a) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $794 million . The remaining affiliated amounts were immaterial. (b) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $136 million . The remaining affiliated amounts were immaterial. (c) Amounts include affiliated and nonaffiliated revenues. Year Ended December 31, 2018 Vertically Integrated Utilities Transmission and Distribution Utilities AEP Transmission Holdco Generation & Marketing Corporate and Other Reconciling Adjustments AEP Consolidated (in millions) Retail Revenues: Residential Revenues $ 3,751.8 $ 2,189.4 $ — $ — $ — $ — $ 5,941.2 Commercial Revenues 2,183.4 1,251.7 — — — — 3,435.1 Industrial Revenues 2,212.8 512.5 — — — — 2,725.3 Other Retail Revenues 183.5 42.7 — — — — 226.2 Total Retail Revenues (a) 8,331.5 3,996.3 — — — — 12,327.8 Wholesale and Competitive Retail Revenues: Generation Revenues (d) 899.8 — — 423.7 — (7.3 ) (e) 1,316.2 Transmission Revenues (b) 282.2 372.1 849.3 — — (737.1 ) 766.5 Renewable Generation Revenues (d) — — — 50.8 — — 50.8 Retail, Trading and Marketing Revenues (c) — — — 1,422.9 — (120.7 ) 1,302.2 Total Wholesale and Competitive Retail Revenues 1,182.0 372.1 849.3 1,897.4 — (865.1 ) 3,435.7 Other Revenues from Contracts with Customers (d) 158.4 204.6 15.2 20.6 86.2 (32.0 ) 453.0 Total Revenues from Contracts with Customers 9,671.9 4,573.0 864.5 1,918.0 86.2 (897.1 ) 16,216.5 Other Revenues: Alternative Revenues (d) (15.9 ) (22.2 ) (60.4 ) — — 52.7 (45.8 ) Other Revenues (d) (10.5 ) 102.3 — 22.3 8.9 (98.0 ) (e) 25.0 Total Other Revenues (26.4 ) 80.1 (60.4 ) 22.3 8.9 (45.3 ) (20.8 ) Total Revenues $ 9,645.5 $ 4,653.1 $ 804.1 $ 1,940.3 $ 95.1 $ (942.4 ) $ 16,195.7 (a) 2018 amounts have been revised to reflect the reclassification of certain customer accounts between Retail classes. This reclassification did not impact previously reported Total Retail Revenues. Management concluded that these prior period disclosure only errors were immaterial individually and in the aggregate. (b) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $643 million . The remaining affiliated amounts were immaterial. (c) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $121 million . The remaining affiliated amounts were immaterial. (d) Amounts include affiliated and nonaffiliated revenues. (e) 2018 amounts have been revised to reflect the reclassification of $98 million of affiliated revenues between Generation Revenues and Other Revenues. This reclassification did not impact previously reported Total Revenues. Management concluded that these prior period disclosure only errors were immaterial individually and in the aggregate. The table below represents revenues from contracts with customers, net of respective provisions for refund, by type of revenue for the Registrant Subsidiaries: Year Ended December 31, 2019 AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Retail Revenues: Residential Revenues $ 571.5 $ — $ 1,266.9 $ 730.0 $ 1,502.0 $ 650.2 $ 638.6 Commercial Revenues 411.5 — 559.9 494.2 738.5 388.5 485.4 Industrial Revenues 129.4 — 592.2 550.7 299.9 303.5 338.7 Other Retail Revenues 29.9 — 75.2 7.3 13.1 81.6 9.0 Total Retail Revenues 1,142.3 — 2,494.2 1,782.2 2,553.5 1,423.8 1,471.7 Wholesale Revenues: Generation Revenues (a) — — 251.5 402.4 — 39.5 194.7 Transmission Revenues (b) 379.2 1,025.5 103.6 25.1 56.0 27.5 106.7 Total Wholesale Revenues 379.2 1,025.5 355.1 427.5 56.0 67.0 301.4 Other Revenues from Contracts with Customers (c) 30.1 16.6 61.8 98.4 139.3 22.0 26.1 Total Revenues from Contracts with Customers 1,551.6 1,042.1 2,911.1 2,308.1 2,748.8 1,512.8 1,799.2 Other Revenues: Alternative Revenues (d) 0.6 (20.7 ) 13.6 (1.4 ) 31.7 (31.0 ) (48.3 ) Other Revenues (d) 157.1 — — — 17.1 — — Total Other Revenues 157.7 (20.7 ) 13.6 (1.4 ) 48.8 (31.0 ) (48.3 ) Total Revenues $ 1,709.3 $ 1,021.4 $ 2,924.7 $ 2,306.7 $ 2,797.6 $ 1,481.8 $ 1,750.9 (a) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $129 million primarily relating to the PPA with KGPCo. The remaining affiliated amounts were immaterial. (b) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEPTCo was $782 million . The remaining affiliated amounts were immaterial. (c) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $73 million primarily relating to the barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial. (d) Amounts include affiliated and nonaffiliated revenues. Year Ended December 31, 2018 AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Retail Revenues: Residential Revenues $ 578.9 $ — $ 1,342.7 $ 730.0 $ 1,611.6 $ 659.0 $ 641.6 Commercial Revenues 414.7 — 580.4 485.0 835.6 394.2 483.9 Industrial Revenues 128.0 — 604.3 565.6 385.2 304.0 333.7 Other Retail Revenues 29.4 — 77.4 7.2 12.9 83.6 8.6 Total Retail Revenues (a) 1,151.0 — 2,604.8 1,787.8 2,845.3 1,440.8 1,467.8 Wholesale Revenues: Generation Revenues (b) — — 250.4 470.5 — 36.3 216.8 Transmission Revenues (c) 313.4 816.9 82.7 23.1 58.5 40.2 108.4 Total Wholesale Revenues 313.4 816.9 333.1 493.6 58.5 76.5 325.2 Other Revenues from Contracts with Customers (d) 28.6 15.1 55.3 99.6 176.1 19.1 24.0 Total Revenues from Contracts with Customers 1,493.0 832.0 2,993.2 2,381.0 3,079.9 1,536.4 1,817.0 Other Revenues: Alternative Revenues (e) (1.3 ) (55.9 ) (23.8 ) (2.1 ) (20.8 ) 10.9 4.9 Other Revenues (e) 103.6 — (1.9 ) (8.2 ) 4.3 — — Total Other Revenues 102.3 (55.9 ) (25.7 ) (10.3 ) (16.5 ) 10.9 4.9 Total Revenues $ 1,595.3 $ 776.1 $ 2,967.5 $ 2,370.7 $ 3,063.4 $ 1,547.3 $ 1,821.9 (a) 2018 amounts have been revised to reflect the reclassification of certain customer accounts between Retail classes. This reclassification did not impact previously reported Total Retail Revenues. Management concluded that these prior period disclosure only errors were immaterial individually and in the aggregate. (b) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $134 million primarily relating to the PPA with KGPCo. The remaining affiliated amounts were immaterial. (c) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEPTCo was $646 million . The remaining affiliated amounts were immaterial. (d) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $70 million primarily relating to the barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial. (e) Amounts include affiliated and nonaffiliated revenues. Performance Obligations AEP has performance obligations as part of its normal course of business. A performance obligation is a promise to transfer a distinct good or service, or a series of distinct goods or services that are substantially the same and have the same pattern of transfer to a customer. The invoice practical expedient within the accounting guidance for “Revenue from Contracts with Customers” allows for the recognition of revenue from performance obligations in the amount of consideration to which there is a right to invoice the customer and when the amount for which there is a right to invoice corresponds directly to the value transferred to the customer. The purpose of the invoice practical expedient is to depict an entity’s measure of progress toward completion of the performance obligation within a contract and can only be applied to performance obligations that are satisfied over time and when the invoice is representative of services provided to date. AEP subsidiaries elected to apply the invoice practical expedient to recognize revenue for performance obligations satisfied over time as the invoices from the respective revenue streams are representative of services or goods provided to date to the customer. Performance obligations for AEP’s subsidiaries are summarized as follows: Retail Revenues AEP’s subsidiaries within the Vertically Integrated Utilities and Transmission and Distribution Utilities segments have performance obligations to generate, transmit and distribute electricity for sale to rate-regulated retail customers. The performance obligation to deliver electricity is satisfied over time as the customer simultaneously receives and consumes the benefits provided. Revenues are variable as they are subject to the customer’s usage requirements. Rate-regulated retail customers typically have the right to discontinue receiving service at will, therefore these contracts between AEP’s subsidiaries and their customers for rate-regulated services are generally limited to the services requested and received to date for such arrangements. Retail customers are generally billed on a monthly basis, and payment is typically due within 15 to 20 days after the issuance of the invoice. Payments from Retail Electric Providers are due to AEP Texas within 35 days. Wholesale Revenues - Generation AEP’s subsidiaries within the Vertically Integrated Utilities and Generation & Marketing segments have performance obligations to sell electricity to wholesale customers from generation assets in PJM, SPP and ERCOT. The performance obligation to deliver electricity from generation assets is satisfied over time as the customer simultaneously receives and consumes the benefits provided. Wholesale generation revenues are variable as they are subject to the customer’s usage requirements. AEP’s subsidiaries within the Vertically Integrated Utilities and Generation & Marketing segments also have performance obligations to stand ready in order to promote grid reliability. Stand ready services are sold into PJM’s RPM capacity market. RPM entails a base auction and at least three incremental auctions for a specific PJM delivery year, with the incremental auctions spanning three years. The performance obligation to stand ready is satisfied over time and the consideration for which is variable until the occurrence of the final incremental auction, at which point the performance obligation becomes fixed. Payments from the RTO for stand ready services are typically received within one week from the issuance of the invoice, which is typically issued weekly. Gross margin resulting from generation sales within the Vertically Integrated Utilities segment are primarily subject to margin sharing agreements with customers and vary by state, where the revenues are reflected gross in the disaggregated revenues tables above. APCo has a performance obligation to supply wholesale electricity to KGPCo through a PPA. The FERC regulates the cost-based wholesale power transactions between APCo and KGPCo. The purchased power agreement includes a component for the recovery of transmission costs under the FERC OATT. The transmission cost component of purchased power is cost-based and regulated by the Tennessee Regulatory Authority. APCo’s performance obligation under the purchased power agreement is satisfied over time as KGPCo simultaneously receives and consumes the wholesale electricity. APCo’s revenues from the purchased power agreement are presented within the Generation Revenues line in the disaggregated revenues tables above. Wholesale Revenues - Transmission AEP’s subsidiaries within the Vertically Integrated Utilities, Transmission and Distribution Utilities and AEP Transmission Holdco segments have performance obligations to transmit electricity to wholesale customers through assets owned and operated by AEP subsidiaries. The performance obligation to provide transmission services in PJM, SPP and ERCOT encompass a time frame greater than a year, where the performance obligation within each RTO is partially fixed for a period of one year or less. Payments from the RTO for transmission services are typically received within one week from the issuance of the invoice, which is issued monthly for SPP and ERCOT and weekly for PJM. AEP subsidiaries within the PJM and SPP regions collect revenues through transmission formula rates. The FERC-approved rates establish the annual transmission revenue requirement (ATRR) and transmission service rates for transmission owners. The formula rates establish rates for a one year period and also include a true-up calculation for the prior year’s billings, allowing for over/under-recovery of the transmission owner’s ATRR. The annual true-ups meet the definition of alternative revenues in accordance with the accounting guidance for “Regulated Operations,” and are therefore presented as such in the disaggregated revenues tables above. AEP subsidiaries within the ERCOT region collect revenues through a combination of base rates and interim Transmission Costs of Services filings that are approved by the PUCT. APCo, I&M, KGPCo, KPCo, OPCo and WPCo (AEP East Companies) are parties to the Transmission Agreement (TA), which defines how transmission costs are allocated among the AEP East Companies on a 12-month average coincident peak basis. PSO, SWEPCo and AEPSC are parties to the Transmission Coordination Agreement (TCA) by and among PSO, SWEPCo and AEPSC, in connection with the operation of the transmission assets of the two AEP utility subsidiaries. AEPTCo is a transmission owner within the PJM and SPP regions providing transmission services to affiliates in accordance with the OATT, TA and TCA. Affiliate revenues as a result of the respective TA and the TCA are reflected as Transmission Revenues in the disaggregated revenues tables above. Marketing, Competitive Retail and Renewable Revenues AEP’s subsidiaries within the Generation & Marketing segment have performance obligations to deliver electricity to competitive retail and wholesale customers. Performance obligations for marketing, competitive retail and renewable offtake sales are satisfied over time as the customer simultaneously receives and consumes the benefits provided. Revenues are primarily variable as they are subject to customer’s usage requirements; however, certain contracts mandate a delivery of a set quantity of electricity at a predetermined price, resulting in a fixed performance obligation. Payment terms under marketing arrangements typically follow standard Edison Electric Institute and International Swaps and Derivatives Association terms, which call for payment in 20 days. Payments for competitive retail and offtake arrangements for renewable assets range from 15 to 60 days and are dependent on the product sold, location and the creditworthiness of customer. Invoices for marketing arrangements, competitive retail and offtake arrangements for renewable assets are issued monthly. Fixed Performance Obligations The following table represents the Registrants’ remaining fixed performance obligations satisfied over time as of December 31, 2019 . Fixed performance obligations primarily include wholesale transmission services, electricity sales for fixed amounts of energy and stand ready services into PJM’s RPM market. The Registrant Subsidiaries amounts shown in the table below include affiliated and nonaffiliated revenues. Company 2020 2021-2022 2023-2024 After 2024 Total (in millions) AEP $ 953.0 $ 160.8 $ 160.6 $ 223.5 $ 1,497.9 AEP Texas 387.0 — — — 387.0 AEPTCo 1,090.7 — — — 1,090.7 APCo 158.0 32.3 23.2 11.6 225.1 I&M 29.6 8.8 8.8 4.4 51.6 OPCo 61.0 — — — 61.0 PSO 11.7 — — — 11.7 SWEPCo 30.4 — — — 30.4 Contract Assets and Liabilities Contract assets are recognized when the Registrants have a right to consideration that is conditional upon the occurrence of an event other than the passage of time, such as future performance under a contract. The Registrants did not have any material contract assets as of December 31, 2019 and 2018 . When the Registrants receive consideration, or such consideration is unconditionally due from a customer prior to transferring goods or services to the customer under the terms of a sales contract, they recognize a contract liability on the balance sheet in the amount of that consideration. Revenue for such consideration is subsequently recognized in the period or periods in which the remaining performance obligations in the contract are satisfied. The Registrants’ contract liabilities typically arise from services provided under joint use agreements for utility poles. The Registrants did not have any material contract liabilities as of December 31, 2019 and 2018 . Accounts Receivable from Contracts with Customers Accounts receivable from contracts with customers are presented on the Registrants’ balance sheets within the Accounts Receivable - Customers line item. The Registrants’ balances for receivables from contracts that are not recognized in accordance with the accounting guidance for “Revenue from Contracts with Customers” included in Accounts Receivable - Customers were not material as of December 31, 2019 and 2018 . See “Securitized Accounts Receivable - AEP Credit” section of Note 14 for additional information. The following table represents the amount of affiliated accounts receivable from contracts with customers included in Accounts Receivable - Affiliated Companies on the Registrant Subsidiaries’ balance sheets: Years Ended December 31, Company 2019 2018 (in millions) AEPTCo $ 65.9 $ 58.6 APCo 47.3 52.5 I&M 37.1 35.3 OPCo 33.9 46.1 PSO 9.7 12.4 SWEPCo 17.6 16.3 Contract Costs Contract costs to obtain or fulfill a contract for AEP subsidiaries within the Generation & Marketing segment are accounted for under the guidance for “Other Assets and Deferred Costs” and presented as a single asset and are neither bifurcated nor reclassified between current and noncurrent assets on the Registrants’ balance sheets. Contract costs to acquire a contract are amortized in a manner consistent with the transfer of goods or services to the customer in Other Operation on the Registrants’ income statements. The Registrants did not have material contract costs as of December 31, 2019 and 2018 .

Unaudited Quarterly Financial I

Unaudited Quarterly Financial Information	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information	UNAUDITED QUARTERLY FINANCIAL INFORMATION The disclosures in this note apply to all Registrants unless indicated otherwise. In management’s opinion, the unaudited quarterly information reflects all normal and recurring accruals and adjustments necessary for a fair presentation of the results of operations for interim periods. Quarterly results are not necessarily indicative of a full year’s operations because of various factors. The unaudited quarterly financial information for each Registrant is as follows: Quarterly Periods Ended: AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) March 31, 2019 Total Revenues $ 4,056.8 $ 390.7 $ 243.5 $ 792.8 $ 614.3 $ 836.8 $ 332.8 $ 421.1 Operating Income 788.4 70.8 141.6 152.1 115.0 162.5 20.9 54.1 Net Income 574.1 34.4 104.3 133.7 98.9 128.0 6.2 29.0 Earnings Attributable to Common Shareholders 572.8 NA NA NA NA NA NA 27.8 June 30, 2019 Total Revenues $ 3,573.6 $ 438.0 $ 266.9 $ 655.8 $ 543.1 $ 606.6 $ 348.1 $ 375.5 Operating Income 551.0 38.7 161.0 76.9 77.9 77.1 56.6 33.0 Net Income 459.1 80.6 136.0 55.5 60.3 50.6 41.9 7.3 Earnings Attributable to Common Shareholders 461.3 NA NA NA NA NA NA 6.2 September 30, 2019 Total Revenues $ 4,315.0 $ 489.3 $ 259.7 $ 755.5 $ 611.1 $ 710.6 $ 493.0 $ 545.5 Operating Income 958.2 118.2 142.3 142.6 107.3 98.6 120.0 134.7 Net Income 733.9 77.0 107.6 104.3 88.8 69.1 100.3 111.3 Earnings Attributable to Common Shareholders 733.5 NA NA NA NA NA NA 110.5 December 31, 2019 Total Revenues $ 3,616.0 $ 391.3 $ 251.3 $ 720.6 $ 538.2 $ 643.6 $ 307.9 $ 408.8 Operating Income 294.7 4.3 122.3 25.7 40.6 63.0 1.8 33.9 Net Income (Loss) 152.7 (13.7 ) 91.8 12.8 21.4 49.4 (10.8 ) 14.6 Earnings Attributable to Common Shareholders 153.5 NA NA NA NA NA NA 14.1 Quarterly Periods Ended: AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) March 31, 2018 Total Revenues $ 4,048.3 $ 371.6 $ 191.7 $ 820.4 $ 576.8 $ 790.9 $ 336.8 $ 419.4 Operating Income 706.0 81.8 111.1 193.0 97.4 117.3 3.9 41.6 Net Income (Loss) 456.7 46.8 84.1 125.5 64.2 79.6 (7.2 ) 13.4 Earnings Attributable to Common Shareholders 454.4 NA NA NA NA NA NA 11.8 June 30, 2018 Total Revenues $ 4,013.2 $ 388.3 $ 200.1 $ 667.0 $ 589.7 $ 748.8 $ 398.3 $ 457.1 Operating Income 757.0 86.2 110.5 132.6 117.4 104.4 57.2 70.5 Net Income 530.1 46.5 82.0 77.4 94.7 68.8 36.6 38.7 Earnings Attributable to Common Shareholders 528.4 NA NA NA NA NA NA 37.6 September 30, 2018 Total Revenues $ 4,333.1 $ 433.4 $ 194.4 $ 762.0 $ 629.7 $ 778.3 $ 481.4 $ 535.3 Operating Income 668.6 94.0 97.0 49.8 110.2 79.9 78.5 127.1 Net Income 579.7 57.8 78.1 87.1 72.7 88.7 60.4 89.6 Earnings Attributable to Common Shareholders 577.6 NA NA NA NA NA NA 88.2 December 31, 2018 Total Revenues $ 3,801.1 $ 402.0 $ 189.9 $ 718.1 $ 574.5 $ 745.4 $ 330.8 $ 410.1 Operating Income 551.1 84.3 91.5 108.1 52.2 118.2 2.9 38.5 Net Income (Loss) 364.8 60.2 71.7 77.8 29.7 88.4 (6.6 ) 10.5 Earnings Attributable to Common Shareholders 363.4 NA NA NA NA NA NA 9.6 NA Not applicable. AEP The unaudited quarterly financial information relating to Common Shareholders is as follows: 2019 Quarterly Periods Ended March 31 June 30 September 30 December 31 Earnings Attributable to AEP Common Shareholders (in millions) $ 572.8 $ 461.3 $ 733.5 $ 153.5 Basic Earnings per Share Attributable to AEP Common Shareholders from Continuing Operations (a) 1.16 0.93 1.49 0.31 Diluted Earnings per Share Attributable to AEP Common Shareholders from Continuing Operations (a) 1.16 0.93 1.48 0.31 2018 Quarterly Periods Ended March 31 June 30 September 30 December 31 Earnings Attributable to AEP Common Shareholders (in millions) $ 454.4 $ 528.4 $ 577.6 $ 363.4 Basic Earnings per Share Attributable to AEP Common Shareholders from Continuing Operations (a) 0.92 1.07 1.17 0.74 Diluted Earnings per Share Attributable to AEP Common Shareholders from Continuing Operations (a) 0.92 1.07 1.17 0.74 (a) Quarterly Earnings per Share amounts are intended to be stand-alone calculations and are not always additive to full-year amount due to rounding.

Organization and Summary of S_2

Organization and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Basis of Accounting	ORGANIZATION The Registrants engage in the generation, transmission and distribution of electric power. The Registrant Subsidiaries that conduct most of these activities are regulated by the FERC under the Federal Power Act and the Energy Policy Act of 2005 and maintain accounts in accordance with the FERC and other regulatory guidelines. Most of these companies are subject to further regulation with regard to rates and other matters by state regulatory commissions. AEP provides competitive electric and gas supply for residential, commercial and industrial customers in deregulated electricity markets and also provides energy management solutions throughout the United States, including energy efficiency services through its independent retail electric supplier. The Registrants also engage in wholesale electricity, natural gas and other commodity marketing and risk management activities in the United States and provide various energy-related services. In addition, AEP operates competitive wind and solar farms. I&M provides barging services to both affiliated and nonaffiliated companies. SWEPCo, through consolidated and nonconsolidated affiliates, conducts lignite mining operations to fuel certain of its generation facilities.
Rates and Service Regulation	Rates and Service Regulation AEP’s public utility subsidiaries’ rates are regulated by the FERC and state regulatory commissions in the eleven state operating territories in which they operate. The FERC also regulates the Registrants’ affiliated transactions, including AEPSC intercompany service billings which are generally at cost, under the 2005 Public Utility Holding Company Act and the Federal Power Act. The FERC also has jurisdiction over the issuances and acquisitions of securities of the public utility subsidiaries, the acquisition or sale of certain utility assets and mergers with another electric utility or holding company. The state regulatory commissions also regulate certain intercompany transactions under various orders and affiliate statutes. Both the FERC and state regulatory commissions are permitted to review and audit the relevant books and records of companies within a public utility holding company system. The FERC regulates wholesale power markets and wholesale power transactions. The Registrants’ wholesale power transactions are generally market-based. Wholesale power transactions are cost-based regulated when a cost-based contract is negotiated and filed with the FERC or the FERC determines that the Registrants have “market power” in the region where the transaction occurs. Wholesale power supply contracts have been entered into with various municipalities and cooperatives that are FERC-regulated, cost-based contracts. These contracts are generally formula rate mechanisms, which are trued up to actual costs annually. The state regulatory commissions regulate all of the retail distribution operations and rates of the Registrants’ retail public utility subsidiaries on a cost basis. The state regulatory commissions also regulate the retail generation/power supply operations and rates except in Ohio and the ERCOT region of Texas. For generation in Ohio, customers who have not switched to a CRES provider for generation pay market-based auction rates. In addition, all OPCo distribution customers paid for certain legacy generation deferral balances that were fully recovered as of December 31, 2019 and continue to pay for certain legacy deferred generation-related costs through PUCO approved riders. In the ERCOT region of Texas, the generation/supply business is under customer choice and market pricing is conducted by REPs. AEP has no active REPs in ERCOT. AEP’s nonregulated subsidiaries enter into short and long-term wholesale transactions to buy or sell capacity, energy and ancillary services in the ERCOT market. In addition, these nonregulated subsidiaries control certain wind and coal-fired generation assets, the power from which is marketed and sold in ERCOT. The FERC also regulates the Registrants’ wholesale transmission operations and rates. Retail transmission rates are based upon the FERC OATT rate when retail rates are unbundled in connection with restructuring. Retail transmission rates are based on formula rates included in the PJM OATT that are cost-based and are unbundled in Ohio for OPCo, in Virginia for APCo and in Michigan for I&M. AEP Texas’ retail transmission rates in Texas are unbundled but the retail transmission rates are regulated, on a cost basis, by the PUCT. Bundled retail transmission rates are regulated, on a cost basis, by the state commissions. Transmission rates for AEPTCo’s seven wholly-owned transmission subsidiaries within the AEP Transmission Holdco segment are based on formula rates included in the applicable RTO’s OATT that are cost-based. In West Virginia, APCo and WPCo provide retail electric service at bundled rates approved by the WVPSC, with rates set on a combined cost-of-service basis. In addition, the FERC regulates the SIA, Operating Agreement, Transmission Agreement and Transmission Coordination Agreement, all of which allocate shared system costs and revenues among the utility subsidiaries that are parties to each agreement. The FERC also regulates the PCA. See Note 16 - Related Party Transactions for additional information.
Principles of Consolidation	Principles of Consolidation AEP’s consolidated financial statements include its wholly-owned and majority-owned subsidiaries and VIEs of which AEP is the primary beneficiary. The consolidated financial statements for AEP Texas include the Registrant Subsidiary, its wholly-owned subsidiaries, Transition Funding (consolidated VIEs) and Restoration Funding (a consolidated VIE). The consolidated financial statements for APCo include the Registrant Subsidiary, its wholly-owned subsidiaries and Appalachian Consumer Rate Relief Funding (a consolidated VIE). The consolidated financial statements for I&M include the Registrant Subsidiary, its wholly-owned subsidiaries and DCC Fuel (consolidated VIEs). The consolidated financial statements for OPCo include the Registrant Subsidiary and Ohio Phase-in-Recovery Funding (a consolidated VIE). In July 2019, the Ohio Phase-in Recovery Funding securitization bonds matured. The consolidated financial statements for SWEPCo include the Registrant Subsidiary, its wholly-owned subsidiary and Sabine (a consolidated VIE). Intercompany items are eliminated in consolidation. The equity method of accounting is used for equity investments where the Registrants exercise significant influence but do not hold a controlling financial interest. Such investments are initially recorded at cost in Deferred Charges and Other Noncurrent Assets on the balance sheets. The proportionate share of the investee’s equity earnings or losses is included in Equity Earnings of Unconsolidated Subsidiaries on the statements of income. AEP, AEP Texas, I&M, PSO and SWEPCo have ownership interests in generating units that are jointly-owned. The proportionate share of the operating costs associated with such facilities is included on the income statements and the assets and liabilities are reflected on the balance sheets. See Note 17 - Variable Interest Entities and Equity Method Investments and Note 18
Accounting for the Effects of Cost-Based Regulation	Accounting for the Effects of Cost-Based Regulation The Registrants’ financial statements reflect the actions of regulators that result in the recognition of certain revenues and expenses in different time periods than enterprises that are not rate-regulated. In accordance with accounting guidance for “Regulated Operations,” regulatory assets (deferred expenses) and regulatory liabilities (deferred revenue reductions or refunds) are recorded to reflect the economic effects of regulation in the same accounting period by matching expenses with their recovery through regulated revenues and by matching income with its passage to customers in cost-based regulated rates.
Use of Estimates	Use of Estimates The preparation of these financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. These estimates include, but are not limited to, inventory valuation, allowance for doubtful accounts, goodwill, intangible and long-lived asset impairment, unbilled electricity revenue, valuation of long-term energy contracts, the effects of regulation, long-lived asset recovery, storm costs, the effects of contingencies and certain assumptions made in accounting for pension and postretirement benefits. The estimates and assumptions used are based upon management’s evaluation of the relevant facts and circumstances as of the date of the financial statements. Actual results could ultimately differ from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and Cash Equivalents include temporary cash investments with original maturities of three months or less.
Restricted Cash for Securitized Funding	Restricted Cash (Applies to AEP, AEP Texas, APCo and OPCo) Restricted Cash primarily includes funds held by trustees for the payment of securitization bonds and contractually restricted deposits held for the future payment of the remaining construction activities at the Santa Rita East wind generation facility.
Other Temporary Investments	Other Temporary Investments (Applies to AEP) Other Temporary Investments primarily include marketable securities and investments by its protected cell of EIS. These securities have readily determinable fair values and are carried at fair value with changes in fair value recognized in net income. The cost of securities sold is based on the specific identification or weighted-average cost method. See “Fair Value Measurements of Other Temporary Investments” section of Note 11 for additional information.
Inventory	Inventory
Accounts Receivable	Accounts Receivable Customer accounts receivable primarily include receivables from wholesale and retail energy customers, receivables from energy contract counterparties related to risk management activities and customer receivables primarily related to other revenue-generating activities. Revenue is recognized over time as the performance obligations of delivering energy to customers are satisfied. To the extent that deliveries have occurred but a bill has not been issued, the Registrants accrue and recognize, as Accrued Unbilled Revenues on the balance sheets, an estimate of the revenues for energy delivered since the last billing. AEP Credit factors accounts receivable on a daily basis, excluding receivables from risk management activities, through purchase agreements with I&M, KGPCo, KPCo, OPCo, PSO, SWEPCo and a portion of APCo. Since APCo does not have regulatory authority to sell accounts receivable in its West Virginia regulatory jurisdiction, only a portion of APCo’s accounts receivable are sold to AEP Credit. AEP Credit has a receivables securitization agreement with bank conduits. Under the securitization agreement, AEP Credit receives financing from bank conduits for the interest in the billed and unbilled receivables they acquire from affiliated utility subsidiaries. See “Securitized Accounts Receivable – AEP Credit” section of Note 14 for additional information.
Allowance for Uncollectible Accounts	Allowance for Uncollectible Accounts Generally, AEP Credit records bad debt expense based upon a 12-month rolling average of bad debt write-offs in proportion to gross accounts receivable purchased from participating AEP subsidiaries. For receivables related to APCo’s West Virginia operations, the bad debt reserve is calculated based on a rolling two-year average write-off in proportion to gross accounts receivable. For customer accounts receivables relating to risk management activities, accounts receivables are reviewed for bad debt reserves at a specific counterparty level basis. For AEP Texas, bad debt reserves are calculated using the specific identification of receivable balances greater than 120 days delinquent, and for those balances less than 120 days where the collection is doubtful. For miscellaneous accounts receivable, bad debt expense is recorded for all amounts outstanding 180 days or greater at 100%, unless specifically identified. Miscellaneous accounts receivable items open less than 180 days may be reserved using specific identification for bad debt reserves.
Concentrations of Credit Risk and Significant Customers	The Registrant Subsidiaries monitor credit levels and the financial condition of their customers on a continuous basis to minimize credit risk. The regulatory commissions allow recovery in rates for a reasonable level of bad debt costs. Management believes adequate provisions for credit loss have been made in the accompanying Registrant Subsidiary financial statements.
Emission Allowances and Renewable Energy Credits	Renewable Energy Credits (Applies to all Registrants except AEP Texas and AEPTCo) In regulated jurisdictions, the Registrants record renewable energy credits (RECs) at cost. For AEP’s competitive generation business, management records RECs at the lower of cost or market. The Registrants follow the inventory model for these RECs. RECs expected to be consumed within one year are reported in Materials and Supplies on the balance sheets. RECs with expected consumption beyond one year are included in Deferred Charges and Other Noncurrent Assets on the balance sheets. The purchases and sales of RECs are reported in the Operating Activities section of the statements of cash flows. RECs are consumed to meet applicable state renewable portfolio standards and are recorded in Fuel and Other Consumables Used for Electric Generation at an average cost on the statements of income. The net margin on sales of RECs affects the determination of deferred fuel and REC costs and the amortization of regulatory assets for certain jurisdictions.
Property, Plant and Equipment and Equity Investments	Property, Plant and Equipment Regulated Electric utility property, plant and equipment for rate-regulated operations are stated at original cost. Additions, major replacements and betterments are added to the plant accounts. Under the group composite method of depreciation, continuous interim routine replacements of items such as boiler tubes, pumps, motors, etc. result in original cost retirements, less salvage, being charged to accumulated depreciation. The group composite method of depreciation assumes that on average, asset components are retired at the end of their useful lives and thus there is no gain or loss. The equipment in each primary electric plant account is identified as a separate group. The depreciation rates that are established take into account the past history of interim capital replacements and the amount of removal cost incurred and salvage received. These rates and the related lives are subject to periodic review. Removal costs accrued are typically recorded as regulatory liabilities when the revenue received for removal costs accrued exceeds actual removal costs incurred. The asset removal costs liability is relieved as removal costs are incurred. A regulatory asset balance will occur if actual removal costs incurred exceed accumulated removal costs accrued. The costs of labor, materials and overhead incurred to operate and maintain plant and equipment are included in operating expenses. Nuclear fuel, including nuclear fuel in the fabrication phase, is included in Other Property, Plant and Equipment on the balance sheets. Long-lived assets are required to be tested for impairment when it is determined that the carrying value of the assets may no longer be recoverable or when the assets meet the held-for-sale criteria under the accounting guidance for “Impairment or Disposal of Long-Lived Assets.” When it becomes probable that an asset in-service or an asset under construction will be abandoned and regulatory cost recovery has been disallowed or is not probable, the cost of that asset shall be removed from plant-in-service or CWIP and charged to expense. The fair value of an asset is the amount at which that asset could be bought or sold in a current transaction between willing parties, as opposed to a forced or liquidation sale. Quoted market prices in active markets are the best evidence of fair value and are used as the basis for the measurement, if available. In the absence of quoted prices for identical or similar assets in active markets, fair value is estimated using various internal and external valuation methods including cash flow analysis and appraisals. Nonregulated Nonregulated operations generally follow the policies of rate-regulated operations listed above but with the following exceptions. Property, plant and equipment of nonregulated operations are stated at original cost (or as adjusted for any applicable impairments) plus the original cost of property acquired or constructed since the acquisition, less disposals. Normal and routine retirements from the plant accounts, net of salvage, are charged to accumulated depreciation for most nonregulated operations under the group composite method of depreciation. A gain or loss would be recorded if the retirement is not considered an interim routine replacement. Removal costs are charged to expense.
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization	Allowance for Funds Used During Construction and Interest Capitalization For regulated operations, AFUDC represents the estimated cost of borrowed and equity funds used to finance construction projects that is capitalized and recovered through depreciation over the service life of regulated electric utility plant. The Registrants record the equity component of AFUDC in Allowance for Equity Funds Used During Construction and the debt component of AFUDC as a reduction to Interest Expense. For nonregulated operations, including certain generating assets, interest is capitalized during construction in accordance with the accounting guidance for “Capitalization of Interest.”
Fair Value Measurements of Assets and Liabilities	Valuation of Nonderivative Financial Instruments The book values of Cash and Cash Equivalents, Advances to/from Affiliates, Accounts Receivable, Accounts Payable and Short-term Debt approximate fair value because of the short-term maturity of these instruments. Fair Value Measurements of Assets and Liabilities (Applies to all Registrants except AEPTCo) The accounting guidance for “Fair Value Measurements and Disclosures” establishes a fair value hierarchy that prioritizes the inputs used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurement) and the lowest priority to unobservable inputs (Level 3 measurement). Where observable inputs are available for substantially the full term of the asset or liability, the instrument is categorized in Level 2. When quoted market prices are not available, pricing may be completed using comparable securities, dealer values, operating data and general market conditions to determine fair value. Valuation models utilize various inputs such as commodity, interest rate and, to a lesser degree, volatility and credit that include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in inactive markets, market corroborated inputs (i.e. inputs derived principally from, or correlated to, observable market data) and other observable inputs for the asset or liability. For commercial activities, exchange-traded derivatives, namely futures contracts, are generally fair valued based on unadjusted quoted prices in active markets and are classified as Level 1. Level 2 inputs primarily consist of OTC broker quotes in moderately active or less active markets, as well as exchange-traded derivatives where there is insufficient market liquidity to warrant inclusion in Level 1. Management verifies price curves using these broker quotes and classifies these fair values within Level 2 when substantially all of the fair value can be corroborated. Management typically obtains multiple broker quotes, which are nonbinding in nature but are based on recent trades in the marketplace. When multiple broker quotes are obtained, the quoted bid and ask prices are averaged. In certain circumstances, a broker quote may be discarded if it is a clear outlier. Management uses a historical correlation analysis between the broker quoted location and the illiquid locations. If the points are highly correlated, these locations are included within Level 2 as well. Certain OTC and bilaterally executed derivative instruments are executed in less active markets with a lower availability of pricing information. Illiquid transactions, complex structured transactions, FTRs and counterparty credit risk may require nonmarket-based inputs. Some of these inputs may be internally developed or extrapolated and utilized to estimate fair value. When such inputs have a significant impact on the measurement of fair value, the instrument is categorized as Level 3. The main driver of contracts being classified as Level 3 is the inability to substantiate energy price curves in the market. A portion of the Level 3 instruments have been economically hedged which limits potential earnings volatility. AEP utilizes its trustee’s external pricing service to estimate the fair value of the underlying investments held in the benefit plan and nuclear trusts. AEP’s investment managers review and validate the prices utilized by the trustee to determine fair value. AEP’s management performs its own valuation testing to verify the fair values of the securities. AEP receives audit reports of the trustee’s operating controls and valuation processes. Assets in the benefits and nuclear trusts, cash and cash equivalents, other temporary investments and restricted cash for securitized funding are classified using the following methods. Equities are classified as Level 1 holdings if they are actively traded on exchanges. Items classified as Level 1 are investments in money market funds, fixed income and equity mutual funds and equity securities. They are valued based on observable inputs, primarily unadjusted quoted prices in active markets for identical assets. Items classified as Level 2 are primarily investments in individual fixed income securities. Fixed income securities generally do not trade on exchanges and do not have an official closing price but their valuation inputs are based on observable market data. Pricing vendors calculate bond valuations using financial models and matrices. The models use observable inputs including yields on benchmark securities, quotes by securities brokers, rating agency actions, discounts or premiums on securities compared to par prices, changes in yields for U.S. Treasury securities, corporate actions by bond issuers, prepayment schedules and histories, economic events and, for certain securities, adjustments to yields to reflect changes in the rate of inflation. Other securities with model-derived valuation inputs that are observable are also classified as Level 2 investments. Investments with unobservable valuation inputs are classified as Level 3 investments. Investments classified as Other are valued using Net Asset Value as a practical expedient. Items classified as Other are primarily cash equivalent funds, common collective trusts, commingled funds, structured products, private equity, real estate, infrastructure and alternative credit investments. These investments do not have a readily determinable fair value or they contain redemption restrictions which may include the right to suspend redemptions under certain circumstances. Redemption restrictions may also prevent certain investments from being redeemed at the reporting date for the underlying value.
Deferred Fuel Costs	Deferred Fuel Costs (Applies to all Registrants except AEP Texas and AEPTCo) The cost of fuel and related emission allowances and emission control chemicals/consumables is charged to Fuel and Other Consumables Used for Electric Generation expense when the fuel is burned or the allowance or consumable is utilized. The cost of fuel also includes the cost of nuclear fuel burned which is computed primarily using the units-of-production method. In regulated jurisdictions with an active FAC, fuel cost over-recoveries (the excess of fuel-related revenues over applicable fuel costs incurred) are generally deferred as current regulatory liabilities and under-recoveries (the excess of applicable fuel costs incurred over fuel-related revenues) are generally deferred as current regulatory assets. Fuel cost over-recovery and under-recovery balances are classified as noncurrent when there is a commission-approved plan to delay refunds or recoveries beyond a one year period. These deferrals are amortized when refunded or when billed to customers in later months with the state regulatory commissions’ review and approval. The amount of an over-recovery or under-recovery can also be affected by actions of the state regulatory commissions. On a routine basis, state regulatory commissions review and/or audit the Registrants’ fuel procurement policies and practices, the fuel cost calculations and FAC deferrals. FAC deferrals are adjusted when costs are no longer probable of recovery or when refunds of fuel reserves are probable. Changes in fuel costs, including purchased power in Kentucky for KPCo, Indiana and Michigan for I&M, in Arkansas, Louisiana and Texas for SWEPCo, in Oklahoma for PSO, in Virginia and West Virginia for APCo and in West Virginia for WPCo are reflected in rates in a timely manner generally through the FAC. In Ohio, purchased power is reflected in rates through various PUCO approved mechanisms. The FAC generally includes some sharing of off-system sales margins. In West Virginia for APCo and WPCo, all of the non-merchant margins from off-system sales are given to customers through the FAC. A portion of margins from off-system sales are given to customers through the FAC and other rate mechanisms in Oklahoma for PSO, Arkansas, Louisiana and Texas for SWEPCo, Kentucky for KPCo, Virginia for APCo and in Indiana and Michigan for I&M. Beginning in 2020, Arkansas for SWEPCo will start giving all margins from off-system sales to customers through the FAC. Where the FAC or off-system sales sharing mechanism is capped, frozen or non-existent, changes in fuel costs or sharing of off-system sales impact earnings.
Revenue Recognition	Revenue Recognition Regulatory Accounting The Registrants’ financial statements reflect the actions of regulators that can result in the recognition of revenues and expenses in different time periods than enterprises that are not rate-regulated. Regulatory assets (deferred expenses or alternative revenues recognized in accordance with the guidance for “Regulated Operations”) and regulatory liabilities (deferred revenue reductions or refunds) are recorded to reflect the economic effects of regulation in the same accounting period by matching expenses with their recovery through regulated revenues and by matching revenue with its passage to customers in cost-based regulated rates. When regulatory assets are probable of recovery through regulated rates, assets are recorded on the balance sheets. Regulatory assets are tested for probability of recovery at each balance sheet date or whenever new events occur. Examples of new events include the issuance of a regulatory commission order or passage of new legislation. If it is determined that recovery of a regulatory asset is no longer probable, the regulatory asset is derecognized as a charge against income. Retail and Wholesale Supply and Delivery of Electricity The Registrants recognize revenues from customers for retail and wholesale electricity sales and electricity transmission and distribution delivery services. The Registrants recognize such revenues on the statements of income as the performance obligations of delivering energy to customers are satisfied. Recognized revenues include both billed and unbilled amounts. In accordance with the applicable state commission’s regulatory treatment, PSO and SWEPCo do not include the fuel portion in unbilled revenue, but rather recognize such revenues when billed to customers. Wholesale transmission revenue is based on FERC approved formula rate filings made for each calendar year using estimated costs. Revenues initially recognized per the annual rate filing are compared to actual costs, resulting in the subsequent recognition of an over or under recovered amount, with interest, that is refunded or recovered, respectively, in a future year’s rates. These annual true-ups meet the definition of alternative revenues in accordance with the accounting guidance for “Regulated Operations”, and are recognized by the Registrants in the second quarter of each calendar year following the filing of annual FERC reports. Any portion of the true-ups applicable to an affiliated company is recorded as Accounts Receivable - Affiliated Companies or Accounts Payable - Affiliated Companies on the balance sheets. Any portion of the true-ups applicable to third-parties is recorded as Regulatory Assets or Regulatory Liabilities on the balance sheets. See Note 20 - Revenue from Contracts with Customers for additional information. Gross versus Net Presentation of Certain Electricity Supply and Delivery Activities Most of the power produced at the generation plants is sold to PJM or SPP. The Registrants also purchase power from PJM and SPP to supply power to customers. Generally, these power sales and purchases are reported on a net basis as revenues on the statements of income. However, purchases of power in excess of sales to PJM or SPP, on an hourly net basis, used to serve retail load are recorded gross as Purchased Electricity for Resale on the statements of income. With the exception of certain dedicated load bilateral power supply contracts, the transactions of AEP’s nonregulated subsidiaries are reported as gross purchases or sales. Physical energy purchases arising from non-derivative contracts are accounted for on a gross basis in Purchased Electricity for Resale on the statements of income. Energy purchases arising from non-trading derivative contracts are recorded based on the transaction’s facts and circumstances. Purchases under non-trading derivatives used to serve accrual based obligations are recorded in Purchased Electricity for Resale on the statements of income. All other non-trading derivative purchases are recorded net in revenues. In general, the Registrants record expenses when purchased electricity is received and when expenses are incurred, with the exception of certain power purchase contracts that are derivatives and accounted for using MTM accounting where generation/supply rates are not cost-based regulated. In jurisdictions where the generation/supply business is subject to cost-based regulation, the unrealized MTM amounts are deferred as regulatory assets (for losses) and regulatory liabilities (for gains). Energy Marketing and Risk Management Activities (Applies to all Registrants except AEPTCo) The Registrants engage in power, capacity and, to a lesser extent, natural gas marketing as major power producers and participants in electricity and natural gas markets. The Registrants also engage in power, capacity, coal, natural gas and, to a lesser extent, heating oil, gasoline and other commodity risk management activities focused on markets where the AEP System owns assets and on adjacent markets. These activities include the purchase-and-sale of energy under forward contracts at fixed and variable prices. These contracts include physical transactions, exchange-traded futures, and to a lesser extent, OTC swaps and options. Certain energy marketing and risk management transactions are with RTOs. The Registrants recognize revenues from marketing and risk management transactions that are not derivatives as the performance obligation of delivering the commodity is satisfied. Expenses from marketing and risk management transactions that are not derivatives are also recognized upon delivery of the commodity. The Registrants use MTM accounting for marketing and risk management transactions that are derivatives unless the derivative is designated in a qualifying cash flow hedge relationship or elected normal under the normal purchase normal sale election. The Registrants include realized gains and losses on marketing and risk management transactions in revenues or expense based on the transaction’s facts and circumstances. In certain jurisdictions subject to cost-based regulation, unrealized MTM amounts and some realized gains and losses are deferred as regulatory assets (for losses) and regulatory liabilities (for gains). Unrealized MTM gains and losses are included on the balance sheets as Risk Management Assets or Liabilities as appropriate. Certain qualifying marketing and risk management derivatives transactions are designated as hedges of variability in future cash flows as a result of forecasted transactions (cash flow hedge). In the event the Registrants designate a cash flow hedge, the cash flow hedge’s gain or loss is initially recorded as a component of AOCI. When the forecasted transaction is realized and affects net income, the Registrants subsequently reclassify the gain or loss on the hedge from AOCI into revenues or expenses within the same financial statement line item as the forecasted transaction on their statements of income. See “Accounting for Cash Flow Hedging Strategies” section of Note 10 for additional information.
Levelization of Nuclear Refueling Outage Costs	Levelization of Nuclear Refueling Outage Costs (Applies to AEP and I&M) In accordance with regulatory orders, I&M defers incremental operation and maintenance costs associated with periodic refueling outages at its Cook Plant and amortizes the costs over approximately 18 months, beginning with the month following the start of each unit’s refueling outage and lasting until the end of the month in which the same unit’s next scheduled refueling outage begins.
Maintenance	Maintenance The Registrants expense maintenance costs as incurred. If it becomes probable that the Registrants will recover specifically-incurred costs through future rates, a regulatory asset is established to match the expensing of those maintenance costs with their recovery in cost-based regulated revenues. In certain regulated jurisdictions, the Registrants defer costs above the level included in base rates and amortize those deferrals commensurate with recovery through rate riders.
Income Taxes and Investment Tax Credits	Income Taxes and Investment and Production Tax Credits The Registrants use the liability method of accounting for income taxes. Under the liability method, deferred income taxes are provided for all temporary differences between the book and tax basis of assets and liabilities which will result in a future tax consequence. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which the temporary differences are expected to be recovered or settled. When the flow-through method of accounting for temporary differences is required by a regulator to be reflected in regulated revenues (that is, when deferred taxes are not included in the cost of service for determining regulated rates for electricity), deferred income taxes are recorded and related regulatory assets and liabilities are established to match the regulated revenues and tax expense. AEP and subsidiaries apply the deferral methodology for the recognition of ITCs. Deferred ITCs are amortized to income tax expense over the life of the asset that generated the credit. Amortization of deferred ITCs begins when the asset is placed into service, except where regulatory commissions reflect ITCs in the rate-making process, then amortization begins when the cash tax benefit is recognized. Alternatively, PTCs reduce income tax expense as they are earned. PTCs are earned when electricity is produced. The Registrants account for uncertain tax positions in accordance with the accounting guidance for “Income Taxes.” The Registrants classify interest expense or income related to uncertain tax positions as interest expense or income as appropriate and classify penalties as Other Operation expense. AEP System Tax Allocation Agreement AEP and subsidiaries join in the filing of a consolidated federal income tax return. The allocation of the AEP System’s current consolidated federal income tax to the AEP System companies allocates the benefit of current tax losses (“Parent Company Loss Benefit”) to the AEP System companies giving rise to such losses in determining their current tax expense. The consolidated net operating loss of the AEP System is allocated to each company in the consolidated group with taxable losses. The tax benefit of the Parent is allocated to its subsidiaries with taxable income. With the exception of the allocation of the consolidated AEP System net operating loss, the loss of the Parent and tax credits, the method of allocation reflects a separate return result for each company in the consolidated group.
Excise Taxes	Excise Taxes (Applies to all Registrants except AEPTCo) As agents for some state and local governments, the Registrants collect from customers certain excise taxes levied by those state or local governments on customers. The Registrants do not record these taxes as revenue or expense.
Debt	Debt Gains and losses from the reacquisition of debt used to finance regulated electric utility plants are deferred and amortized over the remaining term of the reacquired debt in accordance with their rate-making treatment unless the debt is refinanced. If the reacquired debt associated with the regulated business is refinanced, the reacquisition costs attributable to the portions of the business that are subject to cost-based regulatory accounting are generally deferred and amortized over the term of the replacement debt consistent with its recovery in rates. Operations not subject to cost-based rate regulation report gains and losses on the reacquisition of debt in Interest Expense on the statements of income upon reacquisition. Debt discount or premium and debt issuance expenses are deferred and amortized generally utilizing the straight-line method over the term of the related debt. The straight-line method approximates the effective interest method and is consistent with the treatment in rates for regulated operations. The net amortization expense is included in Interest Expense on the statements of income.
Goodwill and Intangible Assets, Policy	Goodwill (Applies to AEP) When AEP acquires a business, as defined by the accounting guidance for “Business Combinations,” management recognizes all acquired assets and liabilities at their fair value. To the extent that consideration exceeds the net fair value of the identified assets and liabilities, goodwill is recognized on the balance sheets. Goodwill is not amortized. Management tests acquired goodwill at the reporting unit level for impairment at least annually at its estimated fair value. Fair value is the amount at which an asset or liability could be bought or sold in a current transaction between willing parties other than in a forced or liquidation sale. Quoted market prices in active markets are the best evidence of fair value and are used as the basis for the measurement, if available. In the absence of quoted prices for identical or similar assets in active markets, management estimates fair value using various internal and external valuation methods.
Pension and Other Postretirement Plans	Pension and OPEB Plans (Applies to all Registrants except AEPTCo) AEP sponsors a qualified pension plan and two unfunded nonqualified pension plans. Substantially all AEP employees are covered by the qualified plan or both the qualified and a nonqualified pension plan. AEP also sponsors OPEB plans to provide health and life insurance benefits for retired employees. The Registrant Subsidiaries account for their participation in the AEP sponsored pension and OPEB plans using multiple-employer accounting. See Note 8 - Benefit Plans for additional information including significant accounting policies associated with the plans. AEP sponsors a qualified pension plan and two unfunded nonqualified pension plans. Substantially all AEP employees are covered by the qualified plan or both the qualified and a nonqualified pension plan. AEP also sponsors OPEB plans to provide health and life insurance benefits for retired employees. Due to the Registrant Subsidiaries’ participation in AEP’s benefit plans, the assumptions used by the actuary, with the exception of the rate of compensation increase, and the accounting for the plans by each subsidiary are the same. This section details the assumptions that apply to all Registrants and the rate of compensation increase for each Registrant. The Registrants recognize the funded status associated with defined benefit pension and OPEB plans on the balance sheets. Disclosures about the plans are required by the “Compensation – Retirement Benefits” accounting guidance. The Registrants recognize an asset for a plan’s overfunded status or a liability for a plan’s underfunded status, and recognize, as a component of other comprehensive income, the changes in the funded status of the plan that arise during the year that are not recognized as a component of net periodic benefit cost. The Registrants record a regulatory asset instead of other comprehensive income for qualifying benefit costs of regulated operations that for ratemaking purposes are deferred for future recovery. The cumulative funded status adjustment is equal to the remaining unrecognized deferrals for unamortized actuarial losses or gains, prior service costs and transition obligations, such that remaining deferred costs result in an AOCI equity reduction or regulatory asset and deferred gains result in an AOCI equity addition or regulatory liability.
Investments Held in Trust for Future Liabilities	Investments Held in Trust for Future Liabilities (Applies to all Registrants except AEPTCo) AEP has several trust funds with significant investments intended to provide for future payments of pension and OPEB benefits, nuclear decommissioning and SNF disposal. All of the trust funds’ investments are diversified and managed in compliance with all laws and regulations. The investment strategy for the trust funds is to use a diversified portfolio of investments to achieve an acceptable rate of return while managing the investment risk of the assets relative to the associated liabilities. To minimize investment risk, the trust funds are broadly diversified among classes of assets, investment strategies and investment managers. Management regularly reviews the actual asset allocations and periodically rebalances the investments to targeted allocations when appropriate. Investment policies and guidelines allow investment managers in approved strategies to use financial derivatives to obtain or manage market exposures and to hedge assets and liabilities. The investments are reported at fair value under the “Fair Value Measurements and Disclosures” accounting guidance. Benefit Plans All benefit plan assets are invested in accordance with each plan’s investment policy. The investment policy outlines the investment objectives, strategies and target asset allocations by plan. The investment philosophies for AEP’s benefit plans support the allocation of assets to minimize risks and optimize net returns. Strategies used include: • Maintaining a long-term investment horizon. • Diversifying assets to help control volatility of returns at acceptable levels. • Managing fees, transaction costs and tax liabilities to maximize investment earnings. • Using active management of investments where appropriate risk/return opportunities exist. • Keeping portfolio structure style-neutral to limit volatility compared to applicable benchmarks. • Using alternative asset classes such as real estate and private equity to maximize return and provide additional portfolio diversification. The objective of the investment policy for the pension fund is to maintain the funded status of the plan while providing for growth in the plan assets to offset the growth in the plan liabilities. The current target asset allocations are as follows: Pension Plan Assets Target Equity 30 % Fixed Income 54 % Other Investments 15 % Cash and Cash Equivalents 1 % OPEB Plans Assets Target Equity 48 % Fixed Income 50 % Cash and Cash Equivalents 2 % The investment policy for each benefit plan contains various investment limitations. The investment policies establish concentration limits for securities and prohibit the purchase of securities issued by AEP (with the exception of proportionate and immaterial holdings of AEP securities in passive index strategies or certain commingled funds). However, the investment policies do not preclude the benefit trust funds from receiving contributions in the form of AEP securities, provided that the AEP securities acquired by each plan may not exceed the limitations imposed by law. For equity investments, the concentration limits are generally as follows: • No security in excess of 5% of all equities. • Cash equivalents must be less than 10% of an investment manager’s equity portfolio. • No individual stock may be more than 10% and 7% for pension and OPEB investments, respectively, of each manager’s equity portfolio. • No securities may be bought or sold on margin or other use of leverage. For fixed income investments, each investment manager’s portfolio is compared to investment grade, diversified long and intermediate benchmark indices. A portion of the pension assets is invested in real estate funds to provide diversification, add return and hedge against inflation. Real estate properties are illiquid, difficult to value and not actively traded. The pension plan uses external real estate investment managers to invest in commingled funds that hold real estate properties. To mitigate investment risk in the real estate portfolio, commingled real estate funds are used to ensure that holdings are diversified by region, property type and risk classification. Real estate holdings include core, value-added and opportunistic classifications. A portion of the pension assets is invested in private equity. Private equity investments add return and provide diversification and typically require a long-term time horizon to evaluate investment performance. Private equity is classified as an alternative investment because it is illiquid, difficult to value and not actively traded. The pension plan uses limited partnerships and commingled funds to invest across the private equity investment spectrum. The private equity holdings are with multiple general partners who help monitor the investments and provide investment selection expertise. The holdings are currently comprised of venture capital, buyout and hybrid debt and equity investments. AEP participates in a securities lending program with BNY Mellon to provide incremental income on idle assets and to provide income to offset custody fees and other administrative expenses. AEP lends securities to borrowers approved by BNY Mellon in exchange for collateral. All loans are collateralized by at least 102% of the loaned asset’s market value and the collateral is invested. The difference between the rebate owed to the borrower and the collateral rate of return determines the earnings on the loaned security. The securities lending program’s objective is to provide modest incremental income with a limited increase in risk. As of December 31, 2019 and 2018 , the fair value of securities on loan as part of the program was $246 million and $241 million , respectively. Cash and securities obtained as collateral exceeded the fair value of the securities loaned as of December 31, 2019 and 2018 . Trust owned life insurance (TOLI) underwritten by The Prudential Insurance Company is held in the OPEB plan trusts. The strategy for holding life insurance contracts in the taxable Voluntary Employees’ Beneficiary Association trust is to minimize taxes paid on the asset growth in the trust. Earnings on plan assets are tax-deferred within the TOLI contract and can be tax-free if held until claims are paid. Life insurance proceeds remain in the trust and are used to fund future retiree medical benefit liabilities. With consideration to other investments held in the trust, the cash value of the TOLI contracts is invested in two diversified funds. A portion is invested in a commingled fund with underlying investments in stocks that are actively traded on major international equity exchanges. The other portion of the TOLI cash value is invested in a diversified, commingled fixed income fund with underlying investments in government bonds, corporate bonds and asset-backed securities. Cash and cash equivalents are held in each trust to provide liquidity and meet short-term cash needs. Cash equivalent funds are used to provide diversification and preserve principal. The underlying holdings in the cash funds are investment grade money market instruments including commercial paper, certificates of deposit, treasury bills and other types of investment grade short-term debt securities. The cash funds are valued each business day and provide daily liquidity.
Nuclear Trust Funds	Nuclear Trust Funds (Applies to AEP and I&M) Nuclear decommissioning and SNF trust funds represent funds that regulatory commissions allow I&M to collect through rates to fund future decommissioning and SNF disposal liabilities. By rules or orders, the IURC, the MPSC and the FERC established investment limitations and general risk management guidelines. In general, limitations include: • Acceptable investments (rated investment grade or above when purchased). • Maximum percentage invested in a specific type of investment. • Prohibition of investment in obligations of AEP, I&M or their affiliates. • Withdrawals permitted only for payment of decommissioning costs and trust expenses. I&M maintains trust funds for each regulatory jurisdiction. Regulatory approval is required to withdraw decommissioning funds. These funds are managed by an external investment manager that must comply with the guidelines and rules of the applicable regulatory authorities. The trust assets are invested to optimize the net of tax earnings of the trust giving consideration to liquidity, risk, diversification and other prudent investment objectives. I&M records securities held in these trust funds in Spent Nuclear Fuel and Decommissioning Trusts on its balance sheets. I&M records these securities at fair value. I&M classifies securities in the trust funds as available-for-sale due to their long-term purpose. With the adoption of ASU 2016-01, effective January 2018, available-for-sale classification only applies to investment in debt securities. Additionally, the adoption of ASU 2016-01 required changes in fair value of equity securities to be recognized in earnings. However, due to the regulatory treatment described below, this is not applicable for I&M’s trust fund securities. Other-than-temporary impairments for investments in debt securities are considered realized losses as a result of securities being managed by an external investment management firm. The external investment management firm makes specific investment decisions regarding the debt and equity investments held in these trusts and generally intends to sell debt securities in an unrealized loss position as part of a tax optimization strategy. Impairments reduce the cost basis of the securities which will affect any future unrealized gain or realized gain or loss due to the adjusted cost of investment. I&M records unrealized gains, unrealized losses and other-than-temporary impairments from securities in these trust funds as adjustments to the regulatory liability account for the nuclear decommissioning trust funds and to regulatory assets or liabilities for the SNF disposal trust funds in accordance with their treatment in rates. Consequently, changes in fair value of trust assets do not affect earnings or AOCI. See the “Nuclear Contingencies” section of Note 6 for additional discussion of nuclear matters. See “Fair Value Measurements of Trust Assets for Decommissioning and SNF Disposal” section of Note 11 for disclosure of the fair value of assets within the trusts.
Comprehensive Income (Loss)	Comprehensive Income (Loss) (Applies to all Registrants except AEPTCo) Comprehensive income (loss) is defined as the change in equity (net assets) of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners. Comprehensive income (loss) has two components: net income (loss) and other comprehensive income (loss).
Stock-based Compensation	Stock-Based Compensation Plans As of December 31, 2019 , AEP had performance shares and restricted stock units outstanding under the American Electric Power System 2015 Long-Term Incentive Plan (2015 LTIP). Upon vesting, all outstanding performance shares and restricted stock units settle in AEP common stock. Performance units awarded prior to 2017 and restricted stock units granted after January 1, 2013 and prior to January 1, 2017 that vested to executive officers were settled in cash. During 2019, all of the remaining performance units and restricted stock units that settle in cash were settled. The impact of AEP’s stock-based compensation plans are insignificant to the financial statements of the Registrant Subsidiaries. AEP maintains a variety of tax qualified and nonqualified deferred compensation plans for employees and non-employee directors that include, among other options, an investment in or an investment return equivalent to that of AEP common stock. This includes AEP career shares maintained under the American Electric Power System Stock Ownership Requirement Plan (SORP), which facilitates executives in meeting minimum stock ownership requirements assigned to them by the Human Resources Committee of the Board of Directors. AEP career shares are derived from vested performance shares granted to employees under the 2015 LTIP. AEP career shares accrue additional dividend shares in an amount equal to dividends paid on AEP common shares at the closing market price on the dividend payments date. All AEP career shares are settled in shares of AEP common stock after the executive’s service with AEP ends. Performance shares awarded after January 1, 2017 are classified as temporary equity in the Mezzanine Equity section of the balance sheets. These awards may be settled in cash upon an employee’s qualifying termination due to a change in control. Because such event is not solely within the control of the company, these awards are classified outside of permanent equity. AEP compensates their non-employee directors, in part, with stock units under the American Electric Power Company, Inc. Stock Unit Accumulation Plan for Non-Employee Directors. These stock units become payable in cash to directors after their service ends. Management measures and recognizes compensation expense for all share-based payment awards to employees and directors based on estimated fair values. For share-based payment awards with service only vesting conditions, management recognizes compensation expense on a straight-line basis. Stock-based compensation expense recognized on the statements of income for the years ended December 31, 2019 , 2018 and 2017 is based on the number of outstanding awards at the end of each period without a reduction for estimated forfeitures. AEP accounts for forfeitures in the period in which they occur. For the years ended December 31, 2019 , 2018 and 2017 , compensation cost is included in Net Income for the performance shares, career shares, restricted stock units and the non-employee director’s stock units. Compensation cost may also be capitalized. See Note 15 - Stock-based Compensation for additional information.
Equity Method Investments	Equity Investment in Unconsolidated Entities (Applies to AEP and SWEPCo) The equity method of accounting is used for equity investments where either AEP or SWEPCo exercise significant influence but do not hold a controlling financial interest. Such investments are initially recorded at cost in Deferred Charges and Other Noncurrent Assets on the balance sheets. The proportionate share of the investee’s equity earnings or losses is included in Equity Earnings (Loss) of Unconsolidated Subsidiaries on the statements of income. AEP and SWEPCo regularly monitor and evaluate equity method investments to determine whether they are impaired. An impairment is recorded when the investment has experienced a decline in value that is other-than-temporary in nature. AEP has various significant equity method investments, which include ETT, DHLC and five wind farms acquired in the purchase of Sempra Renewables LLC. See Note 17 - Variable Interest Entities and Equity Method Investments for additional information.
Earnings Per Share	Earnings Per Share (EPS) (Applies to AEP) Basic EPS is calculated by dividing net earnings available to common shareholders by the weighted-average number of common shares outstanding during the period. Diluted EPS is calculated by adjusting the weighted-average outstanding common shares, assuming conversion of all potentially dilutive stock options and awards.

Benefit Plans (Policies)

Benefit Plans (Policies)	12 Months Ended
	Dec. 31, 2019
Pension and Other Postretirement Plans	Pension and OPEB Plans (Applies to all Registrants except AEPTCo) AEP sponsors a qualified pension plan and two unfunded nonqualified pension plans. Substantially all AEP employees are covered by the qualified plan or both the qualified and a nonqualified pension plan. AEP also sponsors OPEB plans to provide health and life insurance benefits for retired employees. The Registrant Subsidiaries account for their participation in the AEP sponsored pension and OPEB plans using multiple-employer accounting. See Note 8 - Benefit Plans for additional information including significant accounting policies associated with the plans. AEP sponsors a qualified pension plan and two unfunded nonqualified pension plans. Substantially all AEP employees are covered by the qualified plan or both the qualified and a nonqualified pension plan. AEP also sponsors OPEB plans to provide health and life insurance benefits for retired employees. Due to the Registrant Subsidiaries’ participation in AEP’s benefit plans, the assumptions used by the actuary, with the exception of the rate of compensation increase, and the accounting for the plans by each subsidiary are the same. This section details the assumptions that apply to all Registrants and the rate of compensation increase for each Registrant. The Registrants recognize the funded status associated with defined benefit pension and OPEB plans on the balance sheets. Disclosures about the plans are required by the “Compensation – Retirement Benefits” accounting guidance. The Registrants recognize an asset for a plan’s overfunded status or a liability for a plan’s underfunded status, and recognize, as a component of other comprehensive income, the changes in the funded status of the plan that arise during the year that are not recognized as a component of net periodic benefit cost. The Registrants record a regulatory asset instead of other comprehensive income for qualifying benefit costs of regulated operations that for ratemaking purposes are deferred for future recovery. The cumulative funded status adjustment is equal to the remaining unrecognized deferrals for unamortized actuarial losses or gains, prior service costs and transition obligations, such that remaining deferred costs result in an AOCI equity reduction or regulatory asset and deferred gains result in an AOCI equity addition or regulatory liability.

Derivatives and Hedging (Polici

Derivatives and Hedging (Policies)	12 Months Ended
	Dec. 31, 2019
Derivatives and Hedging	Certain qualifying derivative instruments have been designated as normal purchase or normal sale contracts, as provided in the accounting guidance for “Derivatives and Hedging.” Derivative contracts that have been designated as normal purchases or normal sales under that accounting guidance are not subject to MTM accounting treatment and are recognized on the statements of income on an accrual basis. The accounting for the changes in the fair value of a derivative instrument depends on whether it qualifies for and has been designated as part of a hedging relationship and further, on the type of hedging relationship. Depending on the exposure, management designates a hedging instrument as a fair value hedge or a cash flow hedge. For contracts that have not been designated as part of a hedging relationship, the accounting for changes in fair value depends on whether the derivative instrument is held for trading purposes. Unrealized and realized gains and losses on derivative instruments held for trading purposes are included in revenues on a net basis on the statements of income. Unrealized and realized gains and losses on derivative instruments not held for trading purposes are included in revenues or expenses on the statements of income depending on the relevant facts and circumstances. Certain derivatives that economically hedge future commodity risk are recorded in the same expense line item on the statements of income as that of the associated risk. However, unrealized and some realized gains and losses in regulated jurisdictions for both trading and non-trading derivative instruments are recorded as regulatory assets (for losses) or regulatory liabilities (for gains) in accordance with the accounting guidance for “Regulated Operations.” Accounting for Fair Value Hedging Strategies (Applies to AEP) For fair value hedges (i.e. hedging the exposure to changes in the fair value of an asset, liability or an identified portion thereof attributable to a particular risk), the gain or loss on the derivative instrument as well as the offsetting gain or loss on the hedged item associated with the hedged risk impacts net income during the period of change. AEP records realized and unrealized gains or losses on interest rate swaps that are designated and qualify for fair value hedge accounting treatment and any offsetting changes in the fair value of the debt being hedged in Interest Expense on the statements of income. Credit Risk Management mitigates credit risk in wholesale marketing and trading activities by assessing the creditworthiness of potential counterparties before entering into transactions with them and continuing to evaluate their creditworthiness on an ongoing basis. Management uses credit agency ratings and current market-based qualitative and quantitative data as well as financial statements to assess the financial health of counterparties on an ongoing basis. Master agreements are typically used to facilitate the netting of cash flows associated with a single counterparty and may include collateral requirements. Collateral requirements in the form of cash, letters of credit and parental/affiliate guarantees may be obtained as security from counterparties in order to mitigate credit risk. Some master agreements include margining, which requires a counterparty to post cash or letters of credit in the event exposure exceeds the established threshold. The threshold represents an unsecured credit limit which may be supported by a parental/affiliate guaranty, as determined in accordance with AEP’s credit policy. In addition, master agreements allow for termination and liquidation of all positions in the event of a default including a failure or inability to post collateral when required. Collateral Triggering Events Credit Downgrade Triggers (Applies to AEP, APCo, I&M, PSO and SWEPCo) OBJECTIVES FOR UTILIZATION OF DERIVATIVE INSTRUMENTS AEPSC is agent for and transacts on behalf of AEP subsidiaries, including the Registrant Subsidiaries. AEPEP is agent for and transacts on behalf of other AEP subsidiaries. The Registrants are exposed to certain market risks as major power producers and participants in the electricity, capacity, natural gas, coal and emission allowance markets. These risks include commodity price risks which may be subject to capacity risk, interest rate risk and credit risk. These risks represent the risk of loss that may impact the Registrants due to changes in the underlying market prices or rates. Management utilizes derivative instruments to manage these risks. STRATEGIES FOR UTILIZATION OF DERIVATIVE INSTRUMENTS TO ACHIEVE OBJECTIVES Risk Management Strategies The strategy surrounding the use of derivative instruments primarily focuses on managing risk exposures, future cash flows and creating value utilizing both economic and formal hedging strategies. The risk management strategies also include the use of derivative instruments for trading purposes which focus on seizing market opportunities to create value driven by expected changes in the market prices of the commodities. To accomplish these objectives, the Registrants primarily employ risk management contracts including physical and financial forward purchase-and-sale contracts and, to a lesser extent, OTC swaps and options. Not all risk management contracts meet the definition of a derivative under the accounting guidance for “Derivatives and Hedging.” Derivative risk management contracts elected normal under the normal purchases and normal sales scope exception are not subject to the requirements of this accounting guidance. The Registrants utilize power, capacity, coal, natural gas, interest rate and, to a lesser extent, heating oil, gasoline and other commodity contracts to manage the risk associated with the energy business. The Registrants utilize interest rate derivative contracts in order to manage the interest rate exposure associated with the commodity portfolio. For disclosure purposes, such risks are grouped as “Commodity,” as these risks are related to energy risk management activities. The Registrants also utilize derivative contracts to manage interest rate risk associated with debt financing. For disclosure purposes, these risks are grouped as “Interest Rate.” The amount of risk taken is determined by the Commercial Operations, Energy Supply and Finance groups in accordance with established risk management policies as approved by the Finance Committee of the Board of Directors. Accounting for Cash Flow Hedging Strategies For cash flow hedges (i.e. hedging the exposure to variability in expected future cash flows that is attributable to a particular risk), the Registrants initially report the gain or loss on the derivative instrument as a component of Accumulated Other Comprehensive Income (Loss) on the balance sheets until the period the hedged item affects net income. Cross-Default Triggers (Applies to AEP, APCo, I&M and SWEPCo) In addition, a majority of non-exchange-traded commodity contracts contain cross-default provisions that, if triggered, would permit the counterparty to declare a default and require settlement of the outstanding payable. These cross-default provisions could be triggered if there was a non-performance event by Parent or the obligor under outstanding debt or a third-party obligation that is $50 million Fair Value Hedging Strategies (Applies to AEP) Parent enters into interest rate derivative transactions as part of an overall strategy to manage the mix of fixed-rate and floating-rate debt. Certain interest rate derivative transactions effectively modify exposure to interest rate risk by converting a portion of fixed-rate debt to a floating rate. Provided specific criteria are met, these interest rate derivatives may be designated as fair value hedges. Cash Flow Hedging Strategies The Registrants utilize cash flow hedges on certain derivative transactions for the purchase and sale of power (“Commodity”) in order to manage the variable price risk related to forecasted purchases and sales. Management monitors the potential impacts of commodity price changes and, where appropriate, enters into derivative transactions to protect profit margins for a portion of future electricity sales and purchases. The Registrants do not hedge all commodity price risk. The Registrants utilize a variety of interest rate derivative transactions in order to manage interest rate risk exposure. The Registrants also utilize interest rate derivative contracts to manage interest rate exposure related to future borrowings of fixed-rate debt. The Registrants do not hedge all interest rate exposure. ACCOUNTING FOR DERIVATIVE INSTRUMENTS AND THE IMPACT ON THE FINANCIAL STATEMENTS The accounting guidance for “Derivatives and Hedging” requires recognition of all qualifying derivative instruments as either assets or liabilities on the balance sheets at fair value. The fair values of derivative instruments accounted for using MTM accounting or hedge accounting are based on exchange prices and broker quotes. If a quoted market price is not available, the estimate of fair value is based on the best information available including valuation models that estimate future energy prices based on existing market and broker quotes, supply and demand market data and assumptions. In order to determine the relevant fair values of the derivative instruments, the Registrants apply valuation adjustments for discounting, liquidity and credit quality. Credit risk is the risk that a counterparty will fail to perform on the contract or fail to pay amounts due. Liquidity risk represents the risk that imperfections in the market will cause the price to vary from estimated fair value based upon prevailing market supply and demand conditions. Since energy markets are imperfect and volatile, there are inherent risks related to the underlying assumptions in models used to fair value risk management contracts. Unforeseen events may cause reasonable price curves to differ from actual price curves throughout a contract’s term and at the time a contract settles. Consequently, there could be significant adverse or favorable effects on future net income and cash flows if market prices are not consistent with management’s estimates of current market consensus for forward prices in the current period. This is particularly true for longer term contracts. Cash flows may vary based on market conditions, margin requirements and the timing of settlement of risk management contracts.

Fair Value Measurements (Polici

Fair Value Measurements (Policies)	12 Months Ended
	Dec. 31, 2019
Fair Values of Long-term Debt	The fair values of Long-term Debt are based on quoted market prices, without credit enhancements, for the same or similar issues and the current interest rates offered for instruments with similar maturities classified as Level 2 measurement inputs. These instruments are not marked-to-market. The estimates presented are not necessarily indicative of the amounts that could be realized in a current market exchange. The fair value of AEP’s Equity Units (Level 1) are valued based on publicly traded securities issued by AEP.
Fair Value Assets And Liabilities Measured On Recurring Basis	As required by the accounting guidance for “Fair Value Measurements and Disclosures,” financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement.  Management’s assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy levels.  There have not been any significant changes in management’s valuation techniques.

Income Taxes (Policies)

Income Taxes (Policies)	12 Months Ended
	Dec. 31, 2019
Income Tax Policy	Income Taxes and Investment and Production Tax Credits The Registrants use the liability method of accounting for income taxes. Under the liability method, deferred income taxes are provided for all temporary differences between the book and tax basis of assets and liabilities which will result in a future tax consequence. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which the temporary differences are expected to be recovered or settled. When the flow-through method of accounting for temporary differences is required by a regulator to be reflected in regulated revenues (that is, when deferred taxes are not included in the cost of service for determining regulated rates for electricity), deferred income taxes are recorded and related regulatory assets and liabilities are established to match the regulated revenues and tax expense. AEP and subsidiaries apply the deferral methodology for the recognition of ITCs. Deferred ITCs are amortized to income tax expense over the life of the asset that generated the credit. Amortization of deferred ITCs begins when the asset is placed into service, except where regulatory commissions reflect ITCs in the rate-making process, then amortization begins when the cash tax benefit is recognized. Alternatively, PTCs reduce income tax expense as they are earned. PTCs are earned when electricity is produced. The Registrants account for uncertain tax positions in accordance with the accounting guidance for “Income Taxes.” The Registrants classify interest expense or income related to uncertain tax positions as interest expense or income as appropriate and classify penalties as Other Operation expense. AEP System Tax Allocation Agreement AEP and subsidiaries join in the filing of a consolidated federal income tax return. The allocation of the AEP System’s current consolidated federal income tax to the AEP System companies allocates the benefit of current tax losses (“Parent Company Loss Benefit”) to the AEP System companies giving rise to such losses in determining their current tax expense. The consolidated net operating loss of the AEP System is allocated to each company in the consolidated group with taxable losses. The tax benefit of the Parent is allocated to its subsidiaries with taxable income. With the exception of the allocation of the consolidated AEP System net operating loss, the loss of the Parent and tax credits, the method of allocation reflects a separate return result for each company in the consolidated group.

Leases (Policies)

Leases (Policies)	12 Months Ended
	Dec. 31, 2019
Lease Policy	Lease obligations are measured using the discount rate implicit in the lease when that rate is readily determinable. AEP has visibility into the rate implicit in the lease when assets are leased from selected financial institutions under master leasing agreements. When the implicit rate is not readily determinable, the Registrants measure their lease obligation using their estimated secured incremental borrowing rate. Incremental borrowing rates are comprised of an underlying risk free rate and a secured credit spread relative to the lessee on a matched maturity basis.

Stock-Based Compensation (Polic

Stock-Based Compensation (Policies)	12 Months Ended
	Dec. 31, 2019
Stock-based Compensation	Stock-Based Compensation Plans As of December 31, 2019 , AEP had performance shares and restricted stock units outstanding under the American Electric Power System 2015 Long-Term Incentive Plan (2015 LTIP). Upon vesting, all outstanding performance shares and restricted stock units settle in AEP common stock. Performance units awarded prior to 2017 and restricted stock units granted after January 1, 2013 and prior to January 1, 2017 that vested to executive officers were settled in cash. During 2019, all of the remaining performance units and restricted stock units that settle in cash were settled. The impact of AEP’s stock-based compensation plans are insignificant to the financial statements of the Registrant Subsidiaries. AEP maintains a variety of tax qualified and nonqualified deferred compensation plans for employees and non-employee directors that include, among other options, an investment in or an investment return equivalent to that of AEP common stock. This includes AEP career shares maintained under the American Electric Power System Stock Ownership Requirement Plan (SORP), which facilitates executives in meeting minimum stock ownership requirements assigned to them by the Human Resources Committee of the Board of Directors. AEP career shares are derived from vested performance shares granted to employees under the 2015 LTIP. AEP career shares accrue additional dividend shares in an amount equal to dividends paid on AEP common shares at the closing market price on the dividend payments date. All AEP career shares are settled in shares of AEP common stock after the executive’s service with AEP ends. Performance shares awarded after January 1, 2017 are classified as temporary equity in the Mezzanine Equity section of the balance sheets. These awards may be settled in cash upon an employee’s qualifying termination due to a change in control. Because such event is not solely within the control of the company, these awards are classified outside of permanent equity. AEP compensates their non-employee directors, in part, with stock units under the American Electric Power Company, Inc. Stock Unit Accumulation Plan for Non-Employee Directors. These stock units become payable in cash to directors after their service ends. Management measures and recognizes compensation expense for all share-based payment awards to employees and directors based on estimated fair values. For share-based payment awards with service only vesting conditions, management recognizes compensation expense on a straight-line basis. Stock-based compensation expense recognized on the statements of income for the years ended December 31, 2019 , 2018 and 2017 is based on the number of outstanding awards at the end of each period without a reduction for estimated forfeitures. AEP accounts for forfeitures in the period in which they occur. For the years ended December 31, 2019 , 2018 and 2017 , compensation cost is included in Net Income for the performance shares, career shares, restricted stock units and the non-employee director’s stock units. Compensation cost may also be capitalized. See Note 15 - Stock-based Compensation for additional information.
Stock Based Compensation [Member]
Stock-based Compensation	Awards under AEP’s long-term incentive plan may be granted to employees and directors. The Amended and Restated American Electric Power System Long-Term Incentive Plan (the “Prior Plan”), was replaced prospectively for new grants by the American Electric Power System 2015 Long-Term Incentive Plan (the “2015 LTIP”) effective in April 2015. The 2015 LTIP was subsequently amended in September 2016. The 2015 LTIP provides for a maximum of 10 million AEP common shares to be available for grant to eligible employees and directors. As of December 31, 2019 , 7,667,992 shares remained available for issuance under the 2015 LTIP. No new awards may be granted under the Prior Plan. The 2015 LTIP awards may be stock options, stock appreciation rights, restricted stock, restricted stock units, performance shares, performance units, cash-based awards and other stock-based awards. Shares issued pursuant to a stock option or a stock appreciation right reduce the shares remaining available for grants under the 2015 LTIP by 0.286 of a share. Shares issued for any other awards that settles in AEP stock reduce the shares remaining available for grants under the 2015 LTIP by one share. Cash settled awards do not reduce the number of shares remaining available under the 2015 LTIP. The following sections provide further information regarding each type of stock-based compensation award granted under these plans. 1.43 years . Under the 2015 LTIP, AEP is permitted to use authorized but unissued shares, treasury shares, shares acquired in the open market specifically for distribution under these plans, or any combination thereof to fulfill share commitments. AEP’s current practice is to use authorized but unissued shares to fulfill share commitments. The number of shares used to fulfill share commitments is generally reduced to offset AEP’s tax withholding obligation.
Performance Units [Member]
Stock-based Compensation	Performance scores and final awards are determined and approved by the HR Committee in accordance with the pre-established performance measures within approximately two months after the end of the performance period. The performance scores for all performance periods were dependent on two equally-weighted performance measures: (a) three -year total shareholder return measured relative to a peer group of similar companies and (b) three -year cumulative earnings per share measured relative to a target approved by the HR Committee. Monte Carlo Valuation Performance Shares Performance units granted prior to 2017 were settled in cash rather than AEP common stock and did not reduce the number of shares remaining available under the 2015 LTIP. Those performance units had a fair value upon vesting equal to the average closing market price of AEP common stock for the last 20 trading days of the performance period. Performance shares granted in and after 2017 are settled in AEP common stock and will reduce the aggregate share authorization. In all cases the number of performance shares held at the end of the three -year performance period is multiplied by the performance score for such period to determine the actual number of performance shares that participants realize. The performance score can range from 0% to 200% and is determined at the end of the performance period based on performance measures, which include both performance and market conditions, established for each grant at the beginning of the performance period by the Human Resources Committee of AEP’s Board of Directors (HR Committee). Certain employees must satisfy a minimum stock ownership requirement. If those employees have not met their stock ownership requirement, a portion or all of their performance shares are mandatorily deferred as AEP career shares to the extent needed to meet their stock ownership requirement. AEP career shares are a form of non-qualified deferred compensation that has a value equivalent to a share of AEP common stock. AEP career shares are settled in AEP common stock after the participant’s termination of employment. AEP career shares are recorded in Paid-in Capital on the balance sheets. Amounts equivalent to cash dividends on both performance shares and AEP career shares accrue as additional shares. Management records compensation cost for performance shares over an approximately three-year vesting period. The liability for the pre-2017 performance units was recorded in Employee Benefits and Pension Obligations on the balance sheets and was adjusted for changes in value. Performance shares are recorded as mezzanine equity on the balance sheets and compensation cost is calculated at fair value using two equally weighted metrics. The first metric is a total shareholder return measure, which is valued based on a third-party Monte Carlo valuation. The value related to this metric does not change over the three-year vesting period. The second metric is a three-year cumulative earnings per share metric which is adjusted quarterly for changes in performance relative to a target approved by the HR Committee.
Restricted Shares and Restricted Stock Units [Member]
Stock-based Compensation	The HR Committee grants restricted stock units (RSUs), which generally vest, subject to the participant’s continued employment, over at least three years in approximately equal annual increments. The RSUs accrue dividends as additional RSUs. The additional RSUs granted as dividends vest on the same date as the underlying RSUs. RSUs are converted into shares of AEP common stock upon vesting, except the RSUs granted prior to 2017 to AEP’s executive officers which settled in cash. Executive officers are those officers who are subject to the disclosure requirements set forth in Section 16 of the Securities Exchange Act of 1934. For RSUs that settle in shares, compensation cost is measured at fair value on the grant date and recorded over the vesting period. Fair value is determined by multiplying the number of RSUs granted by the grant date market closing price. For RSUs that settled in cash, compensation cost is recorded over the vesting period and adjusted for changes in fair value until vested. The fair value at vesting was determined by multiplying the number of RSUs vested by the 20 -day average closing price of AEP common stock. The maximum contractual term of outstanding RSUs is approximately 40 months from the grant date.
Stock Unit Accumulation Plan for Non Employee Directors [Member]
Stock-based Compensation	AEP also has a Stock Unit Accumulation Plan for Non-Employee Directors providing each non-employee director with AEP stock units as a substantial portion of their quarterly compensation for their services as a director. The number of stock units provided is based on the closing price of AEP common stock on the last trading day of the quarter for which the stock units were earned. Amounts equivalent to cash dividends on the stock units accrue as additional AEP stock units. The stock units granted to non-employee directors are fully vested on their grant date. Stock units are settled in cash upon termination of board service or up to 10 years later if the participant so elects. Cash settlements for stock units are calculated based on the average closing price of AEP common stock for the last 20 trading days prior to the distribution date. After five years of service on the Board of Directors, non-employee directors receive subsequent AEP stock units as contributions to an AEP stock fund awarded under the Stock Unit Accumulation Plan. Such amounts may be exchanged into other market-based investments that are similar to the investment options available to employees that participate in AEP’s Incentive Compensation Deferral Plan. Management records compensation cost for stock units when the units are awarded and adjusts the liability for changes in value based on the current 20 -day average closing price of AEP common stock on the valuation date.

Variable Interest Entities (Pol

Variable Interest Entities (Policies)	12 Months Ended
	Dec. 31, 2019
Variable Interest Entities	The accounting guidance for “Variable Interest Entities” is a consolidation model that considers if a company has a variable interest in a VIE. A VIE is a legal entity that possesses any of the following conditions: the entity’s equity at risk is not sufficient to permit the legal entity to finance its activities without additional subordinated financial support, equity owners are unable to direct the activities that most significantly impact the legal entity’s economic performance (or they possess disproportionate voting rights in relation to the economic interest in the legal entity), or the equity owners lack the obligation to absorb the legal entity’s expected losses or the right to receive the legal entity’s expected residual returns. Entities are required to consolidate a VIE when it is determined that they have a controlling financial interest in a VIE and therefore, are the primary beneficiary of that VIE, as defined by the accounting guidance for “Variable Interest Entities.” In determining whether AEP is the primary beneficiary of a VIE, management considers whether AEP has the power to direct the most significant activities of the VIE and is obligated to absorb losses or receive the expected residual returns that are significant to the VIE. Management believes that significant assumptions and judgments were applied consistently. AEP holds ownership interests in businesses with varying ownership structures. Partnership interests and other variable interests are evaluated to determine if each entity is a VIE, and if so, whether or not the VIE should be consolidated into AEP’s financial statements. AEP has not provided material financial or other support that was not previously contractually required to any of its consolidated VIEs. If an entity is determined not to be a VIE, or if the entity is determined to be a VIE and AEP is not deemed to be the primary beneficiary, the entity is accounted for under the equity method of accounting.

Property, Plant and Equipment (

Property, Plant and Equipment (Policies)	12 Months Ended
	Dec. 31, 2019
Property, Plant and Equipment	SWEPCo provides for depreciation, depletion and amortization of coal-mining assets over each asset’s estimated useful life or the estimated life of each mine, whichever is shorter, using the straight-line method for mining structures and equipment. SWEPCo uses either the straight-line method or the units-of-production method to amortize mine development costs and deplete coal rights based on estimated recoverable tonnages. SWEPCo includes these costs in fuel expense.
Asset Retirement Obligations	The Registrants record ARO in accordance with the accounting guidance for “Asset Retirement and Environmental Obligations” for legal obligations for asbestos removal and for the retirement of certain ash disposal facilities, wind farms, solar farms and certain coal mining facilities. I&M records ARO for the decommissioning of the Cook Plant. The Registrants have identified, but not recognized, ARO liabilities related to electric transmission and distribution assets as a result of certain easements on property on which assets are owned. Generally, such easements are perpetual and require only the retirement and removal of assets upon the cessation of the property’s use. The retirement obligation is not estimable for such easements since the Registrants plan to use their facilities indefinitely. The retirement obligation would only be recognized if and when the Registrants abandon or cease the use of specific easements, which is not expected.

Organization and Summary of S_3

Organization and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Reconciliation of Cash, Cash Equivalents and Restricted Cash	December 31, 2019 AEP AEP Texas APCo OPCo (in millions) Cash and Cash Equivalents $ 246.8 $ 3.1 $ 3.3 $ 3.7 Restricted Cash 185.8 154.7 23.5 — Total Cash, Cash Equivalents and Restricted Cash $ 432.6 $ 157.8 $ 26.8 $ 3.7 December 31, 2018 AEP AEP Texas APCo OPCo (in millions) Cash and Cash Equivalents $ 234.1 $ 3.1 $ 4.2 $ 4.9 Restricted Cash 210.0 156.7 25.6 27.6 Total Cash, Cash Equivalents and Restricted Cash $ 444.1 $ 159.8 $ 29.8 $ 32.5
Significant Customers	Significant Customers of AEPTCo: AEP Subsidiaries 2019 2018 2017 Percentage of Total Revenues 79 % 77 % 80 % Percentage of Total Accounts Receivable 78 % 84 % 85 % Significant Customers of AEP Texas: Centrica, TXU Energy and Reliant Energy 2019 2018 2017 (a) Percentage of Total Revenues 48 % 45 % 35 % Percentage of Accounts Receivable – Customers 43 % 35 % 31 % (a) TXU Energy did not meet the Total Revenue threshold of 10% in order to be considered a significant customer.
Target Asset Allocations	Pension Plan Assets Target Equity 30 % Fixed Income 54 % Other Investments 15 % Cash and Cash Equivalents 1 % OPEB Plans Assets Target Equity 48 % Fixed Income 50 % Cash and Cash Equivalents 2 %
Basic and Diluted EPS Calculations	Years Ended December 31, 2019 2018 2017 (in millions, except per share data) $/share $/share $/share Earnings Attributable to AEP Common Shareholders $ 1,921.1 $ 1,923.8 $ 1,912.6 Weighted Average Number of Basic Shares Outstanding 493.7 $ 3.89 492.8 $ 3.90 491.8 $ 3.89 Weighted Average Dilutive Effect of Stock-Based Awards 1.6 (0.01 ) 1.0 — 0.8 (0.01 ) Weighted Average Number of Diluted Shares Outstanding 495.3 $ 3.88 493.8 $ 3.90 492.6 $ 3.88
Supplementary Information	Years Ended December 31, Cash Flow Information 2019 2018 2017 (in millions) Cash Paid (Received) for: Interest, Net of Capitalized Amounts $ 1,022.5 $ 939.3 $ 858.3 Income Taxes 6.1 (24.7 ) (1.1 ) Noncash Investing and Financing Activities: Acquisitions Under Finance Leases 87.5 55.6 60.7 Construction Expenditures Included in Current Liabilities as of December 31, 1,341.1 1,120.4 1,330.8 Construction Expenditures Included in Noncurrent Liabilities as of December 31, — — 71.8 Acquisition of Nuclear Fuel Included in Current Liabilities as of December 31, 0.1 4.0 — Noncash Contribution of Assets by Noncontrolling Interest — 84.0 — Expected Reimbursement for Spent Nuclear Fuel Dry Cask Storage 0.3 2.2 2.6 Noncontrolling Interest Assumed with Sempra Renewables LLC and Santa Rita East Acquisition 253.4 — — Liabilities Assumed with Sempra Renewable LLC and Santa Rita East Acquisition 32.4 — — 2019 Depreciation and Amortization AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Depreciation and Amortization of Property, Plant and Equipment $ 2,203.7 $ 365.9 $ 176.0 $ 466.5 $ 330.6 $ 229.4 $ 162.5 $ 247.9 Amortization of Certain Securitized Assets 280.7 258.7 — — — 22.0 — — Amortization of Regulatory Assets and Liabilities 30.1 (2.3 ) — 0.3 20.0 (10.5 ) 7.0 1.2 Total Depreciation and Amortization $ 2,514.5 $ 622.3 $ 176.0 $ 466.8 $ 350.6 $ 240.9 $ 169.5 $ 249.1 2018 Depreciation and Amortization AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Depreciation and Amortization of Property, Plant and Equipment $ 1,965.0 $ 262.2 $ 133.9 $ 428.1 $ 278.9 $ 232.6 $ 155.5 $ 237.0 Amortization of Certain Securitized Assets 287.9 240.0 — — — 47.9 — — Amortization of Regulatory Assets and Liabilities 33.7 (2.6 ) — 0.3 14.2 (20.8 ) 8.5 2.5 Total Depreciation and Amortization $ 2,286.6 $ 499.6 $ 133.9 $ 428.4 $ 293.1 $ 259.7 $ 164.0 $ 239.5 2017 Depreciation and Amortization AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Depreciation and Amortization of Property, Plant and Equipment $ 1,709.1 $ 221.1 $ 95.7 $ 407.6 $ 203.1 $ 200.9 $ 131.4 $ 217.2 Amortization of Certain Securitized Assets 275.9 231.4 — — — 44.4 — — Amortization of Regulatory Assets and Liabilities 12.2 (2.4 ) — 0.3 7.8 (19.4 ) (1.0 ) 0.2 Total Depreciation and Amortization $ 1,997.2 $ 450.1 $ 95.7 $ 407.9 $ 210.9 $ 225.9 $ 130.4 $ 217.4

Comprehensive Income (Tables)

Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2019
Changes in Accumulated Other Comprehensive Income (Loss) by Component	AEP Cash Flow Hedges Pension and OPEB For the Year Ended December 31, 2019 Commodity Interest Rate Amortization of Deferred Costs Changes in Funded Status Total (in millions) Balance in AOCI as of December 31, 2018 $ (23.0 ) $ (12.6 ) $ 136.3 $ (221.1 ) $ (120.4 ) Change in Fair Value Recognized in AOCI (127.2 ) (0.2 ) (a) — 57.7 (69.7 ) Amount of (Gain) Loss Reclassified from AOCI Generation & Marketing Revenues (b) (0.2 ) — — — (0.2 ) Purchased Electricity for Resale (b) 59.5 — — — 59.5 Interest Expense (b) — 1.5 — — 1.5 Amortization of Prior Service Cost (Credit) — — (19.2 ) — (19.2 ) Amortization of Actuarial (Gains) Losses — — 12.1 — 12.1 Reclassifications from AOCI, before Income Tax (Expense) Benefit 59.3 1.5 (7.1 ) — 53.7 Income Tax (Expense) Benefit 12.6 0.2 (1.5 ) — 11.3 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 46.7 1.3 (5.6 ) — 42.4 Net Current Period Other Comprehensive Income (Loss) (80.5 ) 1.1 (5.6 ) 57.7 (27.3 ) Balance in AOCI as of December 31, 2019 $ (103.5 ) $ (11.5 ) $ 130.7 $ (163.4 ) $ (147.7 ) AEP Cash Flow Hedges Pension and OPEB For the Year Ended December 31, 2018 Commodity Interest Rate Securities Available for Sale Amortization of Deferred Costs Changes in Funded Status Total (in millions) Balance in AOCI as of December 31, 2017 $ (28.4 ) $ (13.0 ) $ 11.9 $ 141.6 $ (179.9 ) $ (67.8 ) Change in Fair Value Recognized in AOCI 37.3 2.3 — — (33.0 ) 6.6 Amount of (Gain) Loss Reclassified from AOCI Generation & Marketing Revenues (b) (0.1 ) — — — — (0.1 ) Purchased Electricity for Resale (b) (32.6 ) — — — — (32.6 ) Interest Expense (b) — 1.1 — — — 1.1 Amortization of Prior Service Cost (Credit) — — — (19.5 ) — (19.5 ) Amortization of Actuarial (Gains) Losses — — — 12.8 — 12.8 Reclassifications from AOCI, before Income Tax (Expense) Benefit (32.7 ) 1.1 — (6.7 ) — (38.3 ) Income Tax (Expense) Benefit (6.9 ) 0.3 — (1.4 ) — (8.0 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (25.8 ) 0.8 — (5.3 ) — (30.3 ) Net Current Period Other Comprehensive Income (Loss) 11.5 3.1 — (5.3 ) (33.0 ) (23.7 ) ASU 2018-02 Adoption (6.1 ) (2.7 ) — — (8.2 ) (17.0 ) ASU 2016-01 Adoption — — (11.9 ) — — (11.9 ) Balance in AOCI as of December 31, 2018 $ (23.0 ) $ (12.6 ) $ — $ 136.3 $ (221.1 ) $ (120.4 ) Cash Flow Hedges Pension and OPEB For the Year Ended December 31, 2017 Commodity Interest Rate Securities Available for Sale Amortization of Deferred Costs Changes in Funded Status Total (in millions) Balance in AOCI as of December 31, 2016 $ (23.1 ) $ (15.7 ) $ 8.4 $ 140.5 $ (266.4 ) $ (156.3 ) Change in Fair Value Recognized in AOCI (20.4 ) 1.6 3.5 — 86.5 71.2 Amount of (Gain) Loss Reclassified from AOCI Generation & Marketing Revenues (b) (5.6 ) — — — — (5.6 ) Purchased Electricity for Resale (b) 28.8 — — — — 28.8 Interest Expense (b) — 1.5 — — — 1.5 Amortization of Prior Service Cost (Credit) — — — (19.6 ) — (19.6 ) Amortization of Actuarial (Gains) Losses — — — 21.3 — 21.3 Reclassifications from AOCI, before Income Tax (Expense) Benefit 23.2 1.5 — 1.7 — 26.4 Income Tax (Expense) Benefit 8.1 0.4 — 0.6 — 9.1 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 15.1 1.1 — 1.1 — 17.3 Net Current Period Other Comprehensive Income (Loss) (5.3 ) 2.7 3.5 1.1 86.5 88.5 Balance in AOCI as of December 31, 2017 $ (28.4 ) $ (13.0 ) $ 11.9 $ 141.6 $ (179.9 ) $ (67.8 ) AEP Texas Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2019 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2018 $ (4.4 ) $ 4.7 $ (15.4 ) $ (15.1 ) Change in Fair Value Recognized in AOCI — — 1.1 1.1 Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 1.3 — — 1.3 Amortization of Prior Service Cost (Credit) — (0.1 ) — (0.1 ) Amortization of Actuarial (Gains) Losses — 0.3 — 0.3 Reclassifications from AOCI, before Income Tax (Expense) Benefit 1.3 0.2 — 1.5 Income Tax (Expense) Benefit 0.3 — — 0.3 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 1.0 0.2 — 1.2 Net Current Period Other Comprehensive Income (Loss) 1.0 0.2 1.1 2.3 Balance in AOCI as of December 31, 2019 $ (3.4 ) $ 4.9 $ (14.3 ) $ (12.8 ) Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2018 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2017 $ (4.5 ) $ 4.5 $ (12.6 ) $ (12.6 ) Change in Fair Value Recognized in AOCI — — (1.0 ) (1.0 ) Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 1.3 — — 1.3 Amortization of Prior Service Cost (Credit) — (0.1 ) — (0.1 ) Amortization of Actuarial (Gains) Losses — 0.4 — 0.4 Reclassifications from AOCI, before Income Tax (Expense) Benefit 1.3 0.3 — 1.6 Income Tax (Expense) Benefit 0.3 0.1 — 0.4 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 1.0 0.2 — 1.2 Net Current Period Other Comprehensive Income (Loss) 1.0 0.2 (1.0 ) 0.2 ASU 2018-02 Adoption (0.9 ) — (1.8 ) (2.7 ) Balance in AOCI as of December 31, 2018 $ (4.4 ) $ 4.7 $ (15.4 ) $ (15.1 ) Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2017 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2016 $ (5.4 ) $ 4.2 $ (13.7 ) $ (14.9 ) Change in Fair Value Recognized in AOCI — — 1.1 1.1 Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 1.3 — — 1.3 Amortization of Prior Service Cost (Credit) — (0.1 ) — (0.1 ) Amortization of Actuarial (Gains) Losses — 0.5 — 0.5 Reclassifications from AOCI, before Income Tax (Expense) Benefit 1.3 0.4 — 1.7 Income Tax (Expense) Benefit 0.4 0.1 — 0.5 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 0.9 0.3 — 1.2 Net Current Period Other Comprehensive Income (Loss) 0.9 0.3 1.1 2.3 Balance in AOCI as of December 31, 2017 $ (4.5 ) $ 4.5 $ (12.6 ) $ (12.6 ) APCo Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2019 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2018 $ 1.8 $ 11.7 $ (18.5 ) $ (5.0 ) Change in Fair Value Recognized in AOCI — — 13.4 13.4 Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (1.1 ) — — (1.1 ) Amortization of Prior Service Cost (Credit) — (5.3 ) — (5.3 ) Amortization of Actuarial (Gains) Losses — 2.1 — 2.1 Reclassifications from AOCI, before Income Tax (Expense) Benefit (1.1 ) (3.2 ) — (4.3 ) Income Tax (Expense) Benefit (0.2 ) (0.7 ) — (0.9 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (0.9 ) (2.5 ) — (3.4 ) Net Current Period Other Comprehensive Income (Loss) (0.9 ) (2.5 ) 13.4 10.0 Balance in AOCI as of December 31, 2019 $ 0.9 $ 9.2 $ (5.1 ) $ 5.0 Pension and OPEB Cash Flow Hedges Amortization Changes in Interest of Deferred Funded For the Year Ended December 31, 2018 Commodity Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2017 $ — $ 2.2 $ 14.8 $ (15.7 ) $ 1.3 Change in Fair Value Recognized in AOCI (0.7 ) — — (2.6 ) (3.3 ) Amount of (Gain) Loss Reclassified from AOCI Purchased Electricity for Resale (b) 0.9 — — — 0.9 Interest Expense (b) — (1.1 ) — — (1.1 ) Amortization of Prior Service Cost (Credit) — — (5.2 ) — (5.2 ) Amortization of Actuarial (Gains) Losses — — 1.3 — 1.3 Reclassifications from AOCI, before Income Tax (Expense) Benefit 0.9 (1.1 ) (3.9 ) — (4.1 ) Income Tax (Expense) Benefit 0.2 (0.2 ) (0.8 ) — (0.8 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 0.7 (0.9 ) (3.1 ) — (3.3 ) Net Current Period Other Comprehensive Income (Loss) — (0.9 ) (3.1 ) (2.6 ) (6.6 ) ASU 2018-02 Adoption — 0.5 — (0.2 ) 0.3 Balance in AOCI as of December 31, 2018 $ — $ 1.8 $ 11.7 $ (18.5 ) $ (5.0 ) Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2017 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2016 $ 2.9 $ 16.0 $ (27.3 ) $ (8.4 ) Change in Fair Value Recognized in AOCI — — 11.6 11.6 Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (1.1 ) — — (1.1 ) Amortization of Prior Service Cost (Credit) — (5.2 ) — (5.2 ) Amortization of Actuarial (Gains) Losses — 3.4 — 3.4 Reclassifications from AOCI, before Income Tax (Expense) Benefit (1.1 ) (1.8 ) — (2.9 ) Income Tax (Expense) Benefit (0.4 ) (0.6 ) — (1.0 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (0.7 ) (1.2 ) — (1.9 ) Net Current Period Other Comprehensive Income (Loss) (0.7 ) (1.2 ) 11.6 9.7 Balance in AOCI as of December 31, 2017 $ 2.2 $ 14.8 $ (15.7 ) $ 1.3 I&M Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2019 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2018 $ (11.5 ) $ 5.1 $ (7.4 ) $ (13.8 ) Change in Fair Value Recognized in AOCI — — 0.8 0.8 Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 2.0 — — 2.0 Amortization of Prior Service Cost (Credit) — (0.8 ) — (0.8 ) Amortization of Actuarial (Gains) Losses — 0.6 — 0.6 Reclassifications from AOCI, before Income Tax (Expense) Benefit 2.0 (0.2 ) — 1.8 Income Tax (Expense) Benefit 0.4 — — 0.4 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 1.6 (0.2 ) — 1.4 Net Current Period Other Comprehensive Income (Loss) 1.6 (0.2 ) 0.8 2.2 Balance in AOCI as of December 31, 2019 $ (9.9 ) $ 4.9 $ (6.6 ) $ (11.6 ) Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2018 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2017 $ (10.7 ) $ 5.1 $ (6.5 ) $ (12.1 ) Change in Fair Value Recognized in AOCI — — (0.6 ) (0.6 ) Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 2.0 — — 2.0 Amortization of Prior Service Cost (Credit) — (0.8 ) — (0.8 ) Amortization of Actuarial (Gains) Losses — 0.8 — 0.8 Reclassifications from AOCI, before Income Tax (Expense) Benefit 2.0 — — 2.0 Income Tax (Expense) Benefit 0.4 — — 0.4 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 1.6 — — 1.6 Net Current Period Other Comprehensive Income (Loss) 1.6 — (0.6 ) 1.0 ASU 2018-02 Adoption (2.4 ) — (0.3 ) (2.7 ) Balance in AOCI as of December 31, 2018 $ (11.5 ) $ 5.1 $ (7.4 ) $ (13.8 ) Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2017 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2016 $ (12.0 ) $ 5.1 $ (9.3 ) $ (16.2 ) Change in Fair Value Recognized in AOCI — — 2.8 2.8 Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 2.0 — — 2.0 Amortization of Prior Service Cost (Credit) — (0.9 ) — (0.9 ) Amortization of Actuarial (Gains) Losses — 0.9 — 0.9 Reclassifications from AOCI, before Income Tax (Expense) Benefit 2.0 — — 2.0 Income Tax (Expense) Benefit 0.7 — — 0.7 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 1.3 — — 1.3 Net Current Period Other Comprehensive Income (Loss) 1.3 — 2.8 4.1 Balance in AOCI as of December 31, 2017 $ (10.7 ) $ 5.1 $ (6.5 ) $ (12.1 ) OPCo Cash Flow Hedge – For the Year Ended December 31, 2019 Interest Rate (in millions) Balance in AOCI as of December 31, 2018 $ 1.0 Change in Fair Value Recognized in AOCI — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (1.3 ) Reclassifications from AOCI, before Income Tax (Expense) Benefit (1.3 ) Income Tax (Expense) Benefit (0.3 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (1.0 ) Net Current Period Other Comprehensive Income (Loss) (1.0 ) Balance in AOCI as of December 31, 2019 $ — Cash Flow Hedge – For the Year Ended December 31, 2018 Interest Rate (in millions) Balance in AOCI as of December 31, 2017 $ 1.9 Change in Fair Value Recognized in AOCI — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (1.7 ) Reclassifications from AOCI, before Income Tax (Expense) Benefit (1.7 ) Income Tax (Expense) Benefit (0.4 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (1.3 ) Net Current Period Other Comprehensive Income (Loss) (1.3 ) ASU 2018-02 Adoption 0.4 Balance in AOCI as of December 31, 2018 $ 1.0 Cash Flow Hedge – For the Year Ended December 31, 2017 Interest Rate (in millions) Balance in AOCI as of December 31, 2016 $ 3.0 Change in Fair Value Recognized in AOCI — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (1.7 ) Reclassifications from AOCI, before Income Tax (Expense) Benefit (1.7 ) Income Tax (Expense) Benefit (0.6 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (1.1 ) Net Current Period Other Comprehensive Income (Loss) (1.1 ) Balance in AOCI as of December 31, 2017 $ 1.9 PSO Cash Flow Hedge – For the Year Ended December 31, 2019 Interest Rate (in millions) Balance in AOCI as of December 31, 2018 $ 2.1 Change in Fair Value Recognized in AOCI — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (1.3 ) Reclassifications from AOCI, before Income Tax (Expense) Benefit (1.3 ) Income Tax (Expense) Benefit (0.3 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (1.0 ) Net Current Period Other Comprehensive Income (Loss) (1.0 ) Balance in AOCI as of December 31, 2019 $ 1.1 Cash Flow Hedge – For the Year Ended December 31, 2018 Interest Rate (in millions) Balance in AOCI as of December 31, 2017 $ 2.6 Change in Fair Value Recognized in AOCI — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (1.3 ) Reclassifications from AOCI, before Income Tax (Expense) Benefit (1.3 ) Income Tax (Expense) Benefit (0.3 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (1.0 ) Net Current Period Other Comprehensive Income (Loss) (1.0 ) ASU 2018-02 Adoption 0.5 Balance in AOCI as of December 31, 2018 $ 2.1 Cash Flow Hedge – For the Year Ended December 31, 2017 Interest Rate (in millions) Balance in AOCI as of December 31, 2016 $ 3.4 Change in Fair Value Recognized in AOCI — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (1.3 ) Reclassifications from AOCI, before Income Tax (Expense) Benefit (1.3 ) Income Tax (Expense) Benefit (0.5 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (0.8 ) Net Current Period Other Comprehensive Income (Loss) (0.8 ) Balance in AOCI as of December 31, 2017 $ 2.6 SWEPCo Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2019 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2018 $ (3.3 ) $ (0.2 ) $ (1.9 ) $ (5.4 ) Change in Fair Value Recognized in AOCI — — 3.7 3.7 Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 1.9 — — 1.9 Amortization of Prior Service Cost (Credit) — (2.0 ) — (2.0 ) Amortization of Actuarial (Gains) Losses — 0.6 — 0.6 Reclassifications from AOCI, before Income Tax (Expense) Benefit 1.9 (1.4 ) — 0.5 Income Tax (Expense) Benefit 0.4 (0.3 ) — 0.1 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 1.5 (1.1 ) — 0.4 Net Current Period Other Comprehensive Income (Loss) 1.5 (1.1 ) 3.7 4.1 Balance in AOCI as of December 31, 2019 $ (1.8 ) $ (1.3 ) $ 1.8 $ (1.3 ) Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2018 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2017 $ (6.0 ) $ 1.2 $ 0.8 $ (4.0 ) Change in Fair Value Recognized in AOCI 2.3 — (3.1 ) (0.8 ) Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 2.1 — — 2.1 Amortization of Prior Service Cost (Credit) — (2.0 ) — (2.0 ) Amortization of Actuarial (Gains) Losses — 0.2 — 0.2 Reclassifications from AOCI, before Income Tax (Expense) Benefit 2.1 (1.8 ) — 0.3 Income Tax (Expense) Benefit 0.4 (0.4 ) — — Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 1.7 (1.4 ) — 0.3 Net Current Period Other Comprehensive Income (Loss) 4.0 (1.4 ) (3.1 ) (0.5 ) ASU 2018-02 Adoption (1.3 ) — 0.4 (0.9 ) Balance in AOCI as of December 31, 2018 $ (3.3 ) $ (0.2 ) $ (1.9 ) $ (5.4 ) Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2017 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2016 $ (7.4 ) $ 1.9 $ (3.9 ) $ (9.4 ) Change in Fair Value Recognized in AOCI — — 4.7 4.7 Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 2.2 — — 2.2 Amortization of Prior Service Cost (Credit) — (2.0 ) — (2.0 ) Amortization of Actuarial (Gains) Losses — 0.9 — 0.9 Reclassifications from AOCI, before Income Tax (Expense) Benefit 2.2 (1.1 ) — 1.1 Income Tax (Expense) Benefit 0.8 (0.4 ) — 0.4 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 1.4 (0.7 ) — 0.7 Net Current Period Other Comprehensive Income (Loss) 1.4 (0.7 ) 4.7 5.4 Balance in AOCI as of December 31, 2017 $ (6.0 ) $ 1.2 $ 0.8 $ (4.0 ) (a) The change in fair value includes $4 million related to AEP's investment in joint venture wind farms acquired as part of the purchase of Sempra Renewables LLC for the year ended December 31, 2019. See “Sempra Renewables LLC” section of Note 17 for additional information. (b) Amounts reclassified to the referenced line item on the statements of income.

Effects of Regulation (Tables)

Effects of Regulation (Tables)	12 Months Ended
	Dec. 31, 2019
Regulated Generating Units to be Retired	Plant Gross Investment Accumulated Depreciation Net Investment Accelerated Depreciation Regulatory Asset Materials and Supplies Cost of Removal Regulatory Liability Expected Retirement Date Remaining Recovery Period (dollars in millions) Oklaunion Power Station $ 106.7 $ 86.6 $ 20.1 $ 27.4 (a) $ 3.2 $ 5.1 2020 27 years Dolet Hills Power Station 338.9 194.2 144.7 — (b) 5.8 23.6 2026 27 years (a) In October 2018, PSO changed depreciation rates to utilize the 2020 end-of-life and defer depreciation expense to a regulatory asset for the amount in excess of the previously OCC-approved depreciation rates for Oklaunion Power Station. See “2018 Oklahoma Base Rate Case” section of Note 4 for additional information. (b) Beginning in January 2020, SWEPCo began recording a regulatory asset for accelerated depreciation.
Regulatory Assets	AEP December 31, Remaining Recovery Period 2019 2018 Current Regulatory Assets (in millions) Under-recovered Fuel Costs - earns a return $ 44.7 $ 101.7 1 year Under-recovered Fuel Costs - does not earn a return 48.2 48.4 1 year Total Current Regulatory Assets $ 92.9 $ 150.1 Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Unrecovered Plant $ 35.2 $ 50.3 Kentucky Deferred Purchased Power Expenses 30.2 14.5 Oklaunion Power Station Accelerated Depreciation 27.4 5.5 Other Regulatory Assets Pending Final Regulatory Approval 0.7 9.3 Total Regulatory Assets Currently Earning a Return 93.5 79.6 Regulatory Assets Currently Not Earning a Return Plant Retirement Costs - Asset Retirement Obligation Costs 30.1 35.3 Vegetation Management Program - AEP Texas (a) 29.4 — Cook Plant Study Costs 7.6 — Storm-Related Costs (b) 7.2 152.4 Asset Retirement Obligation - Louisiana 7.2 5.3 Other Regulatory Assets Pending Final Regulatory Approval 6.7 15.4 Total Regulatory Assets Currently Not Earning a Return 88.2 208.4 Total Regulatory Assets Pending Final Regulatory Approval (c) 181.7 288.0 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Unrecovered Plant 690.5 680.9 23 years Plant Retirement Costs - Asset Retirement Obligation Costs 87.4 64.3 21 years Meter Replacement Costs 65.4 74.4 8 years Environmental Control Projects 41.0 43.4 21 years Cook Plant Uprate Project 32.6 35.0 14 years Ohio Distribution Decoupling 31.4 12.3 2 years Advanced Metering System 26.5 45.3 2 years Storm-Related Costs 21.3 31.1 3 years Mitchell Plant Transfer - West Virginia 16.2 17.0 21 years Deferred Cook Plant Life Cycle Management Project Costs - Michigan 15.1 16.1 15 years Cook Plant Turbine 13.4 15.8 19 years Ohio Capacity Deferral — 57.8 Other Regulatory Assets Approved for Recovery 48.4 46.1 various Total Regulatory Assets Currently Earning a Return 1,089.2 1,139.5 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 1,309.8 1,326.6 11 years Unamortized Loss on Reacquired Debt 129.0 134.2 29 years Unrealized Loss on Forward Commitments 106.8 104.6 13 years Cook Plant Nuclear Refueling Outage Levelization 63.8 37.5 3 years Vegetation Management - West Virginia 43.6 26.6 2 years Postemployment Benefits 34.2 35.6 4 years Plant Retirement Costs - Asset Retirement Obligation Costs 28.8 21.6 23 years Medicare Subsidy 23.2 27.9 5 years Peak Demand Reduction/Energy Efficiency 18.6 31.9 7 years PJM/SPP Annual Formula Rate True Up 7.3 22.0 2 years PJM Costs and Off-system Sales Margin Sharing - Indiana — 20.1 Other Regulatory Assets Approved for Recovery 122.8 94.3 various Total Regulatory Assets Currently Not Earning a Return 1,887.9 1,882.9 Total Regulatory Assets Approved for Recovery 2,977.1 3,022.4 Total Noncurrent Regulatory Assets $ 3,158.8 $ 3,310.4 (a) Includes $26 million of deferred expenses from a stipulation and settlement agreement filed in February 2020. See “2019 Texas Base Rate Case” section of Note 4 - Rate Matters for additional information. (b) In September 2019, AEP Texas securitized $235 million of storm-related costs. As a result of the securitization, the regulatory asset balance was transferred to Securitized Assets on the balance sheets. See “Texas Storm Cost Securitization” section of Note 4 - Rate Matters for additional information. (c) In 2015, APCo recorded a $91 million reduction, before cost of removal which was $11 million and $20 million as of December 31, 2019 and 2018, respectively, to Accumulated Depreciation and Amortization related to the remaining net book value of coal plants retired in 2015, primarily related to APCo’s Virginia jurisdiction. The net book value of these plants at the retirement date was $93 million before cost of removal, including materials and supplies inventory. Based on management’s interpretation of Virginia law and more certainty regarding APCo’s triennial revenues, expenses and resulting earnings upon reaching the end of the three-year review period, APCo recorded a pretax expense of $93 million related to its previously retired coal-fired generation assets. This expense is included in Asset Impairments and Other Related Charges on the statements of income. APCo is currently in the process of retiring and replacing its Virginia jurisdictional Automated Meter Reading (AMR) meters with Advanced Metering Infrastructure (AMI) meters. As of December 31, 2019, APCo has approximately $51 million of Virginia jurisdictional AMR meters recorded in Total Property, Plant and Equipment - Net on its balance sheets. APCo intends to pursue full recovery of these assets through future depreciation rates. AEP Texas December 31, Remaining Recovery Period Regulatory Assets: 2019 2018 (in millions) Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Not Earning a Return Vegetation Management Program (a) $ 29.4 $ — Storm-Related Costs (b) — 152.4 Other Regulatory Assets Pending Final Regulatory Approval 1.4 0.2 Total Regulatory Assets Pending Final Regulatory Approval 30.8 152.6 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Meter Replacement Costs 35.2 40.1 8 years Advanced Metering System 26.5 45.3 2 years Total Regulatory Assets Currently Earning a Return 61.7 85.4 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 172.0 176.9 11 years Unamortized Loss on Reacquired Debt 6.4 6.0 18 years Other Regulatory Assets Approved for Recovery 9.7 9.1 various Total Regulatory Assets Currently Not Earning a Return 188.1 192.0 Total Regulatory Assets Approved for Recovery 249.8 277.4 Total Noncurrent Regulatory Assets $ 280.6 $ 430.0 (a) Includes $26 million of deferred expenses from a stipulation and settlement agreement filed in February 2020. See “2019 Texas Base Rate Case” section of Note 4 - Rate Matters for additional information. (b) In September 2019, AEP Texas securitized $235 million of storm-related costs. As a result of the securitization, the regulatory asset balance was transferred to Securitized Assets on the balance sheets. See “Texas Storm Cost Securitization” section of Note 4 - Rate Matters for additional information. I&M December 31, Remaining Recovery Period Regulatory Assets: 2019 2018 (in millions) Current Regulatory Assets Under-recovered Fuel Costs - earns a return $ 3.0 $ — 1 Year Total Current Regulatory Assets $ 3.0 $ — Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Not Earning a Return Cook Plant Study Costs $ 7.6 $ — Other Regulatory Assets Pending Final Regulatory Approval 0.1 3.3 Total Regulatory Assets Pending Final Regulatory Approval 7.7 3.3 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Unrecovered Plant 214.9 232.2 9 years Cook Plant Uprate Project 32.6 35.0 14 years Deferred Cook Plant Life Cycle Management Project Costs - Michigan 15.1 16.1 15 years Cook Plant Turbine 13.4 15.8 19 years Rockport Plant Dry Sorbent Injection System - Indiana 10.2 11.5 8 years Cook Plant, Unit 2 Baffle Bolts - Indiana 5.4 5.7 19 years Other Regulatory Assets Approved for Recovery 4.8 2.4 various Total Regulatory Assets Currently Earning a Return 296.4 318.7 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 67.5 84.9 11 years Cook Plant Nuclear Refueling Outage Levelization 63.8 37.5 3 years Unamortized Loss on Reacquired Debt 17.2 18.7 29 years Postemployment Benefits 7.2 6.5 4 years PJM Costs and Off-system Sales Margin Sharing - Indiana — 20.1 Other Regulatory Assets Approved for Recovery 22.3 22.8 various Total Regulatory Assets Currently Not Earning a Return 178.0 190.5 Total Regulatory Assets Approved for Recovery 474.4 509.2 Total Noncurrent Regulatory Assets $ 482.1 $ 512.5 APCo December 31, Remaining Recovery Period Regulatory Assets: 2019 2018 (in millions) Current Regulatory Assets Under-recovered Fuel Costs, Virginia - earns a return $ 36.8 $ 82.4 1 year Under-recovered Fuel Costs, West Virginia - does not earn a return 5.7 17.2 1 year Total Current Regulatory Assets $ 42.5 $ 99.6 Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Materials and Supplies $ 0.5 $ 9.0 Total Regulatory Assets Currently Earning a Return 0.5 9.0 Regulatory Assets Currently Not Earning a Return Plant Retirement Costs - Asset Retirement Obligation Costs 30.1 35.3 Other Regulatory Assets Pending Final Regulatory Approval — 0.6 Total Regulatory Assets Currently Not Earning a Return 30.1 35.9 Total Regulatory Assets Pending Final Regulatory Approval (a) 30.6 44.9 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Unrecovered Plant - West Virginia 86.4 85.3 24 years Other Regulatory Assets Approved for Recovery 0.5 1.2 various Total Regulatory Assets Currently Earning a Return 86.9 86.5 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 160.8 172.2 11 years Unamortized Loss on Reacquired Debt 85.5 89.3 23 years Vegetation Management Program - West Virginia 43.6 26.6 2 years Peak Demand Reduction/Energy Efficiency 19.5 19.7 7 years Postemployment Benefits 15.9 18.0 4 years Virginia Generation Rate Adjustment Clause 5.1 10.3 2 years Other Regulatory Assets Approved for Recovery 9.3 8.3 various Total Regulatory Assets Currently Not Earning a Return 339.7 344.4 Total Regulatory Assets Approved for Recovery 426.6 430.9 Total Noncurrent Regulatory Assets $ 457.2 $ 475.8 (a) In 2015, APCo recorded a $91 million reduction, before cost of removal which was $11 million and $20 million as of December 31, 2019 and 2018, respectively, to Accumulated Depreciation and Amortization related to the remaining net book value of coal plants retired in 2015, primarily related to APCo’s Virginia jurisdiction. The net book value of these plants at the retirement date was $93 million before cost of removal, including materials and supplies inventory. Based on management’s interpretation of Virginia law and more certainty regarding APCo’s triennial revenues, expenses and resulting earnings upon reaching the end of the three-year review period, APCo recorded a pretax expense of $93 million related to its previously retired coal-fired generation assets. This expense is included in Asset Impairments and Other Related Charges on the statements of income. APCo is currently in the process of retiring and replacing its Virginia jurisdictional Automated Meter Reading (AMR) meters with Advanced Metering Infrastructure (AMI) meters. As of December 31, 2019, APCo has approximately $51 million of Virginia jurisdictional AMR meters recorded in Total Property, Plant and Equipment - Net on its balance sheets. APCo intends to pursue full recovery of these assets through future depreciation rates. SWEPCo December 31, Remaining Recovery Period 2019 2018 Regulatory Assets: (in millions) Current Regulatory Assets Under-recovered Fuel Costs - earns a return (a) $ 4.9 $ 18.8 1 year Total Current Regulatory Assets $ 4.9 $ 18.8 Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Unrecovered Plant, Louisiana $ 35.2 $ 50.3 Other Regulatory Assets Pending Final Regulatory Approval 0.2 0.3 Total Regulatory Assets Currently Earning a Return 35.4 50.6 Regulatory Assets Currently Not Earning a Return Asset Retirement Obligation - Louisiana 7.2 5.3 Rate Case Expense - Texas 1.0 4.9 Other Regulatory Assets Pending Final Regulatory Approval 2.7 3.6 Total Regulatory Assets Currently Not Earning a Return 10.9 13.8 Total Regulatory Assets Pending Final Regulatory Approval 46.3 64.4 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Unrecovered Plant, Arkansas 15.1 — 23 years Environmental Controls Projects 13.2 14.2 13 years Other Regulatory Assets Approved for Recovery 8.9 7.2 various Total Regulatory Assets Currently Earning a Return 37.2 21.4 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 102.6 108.4 11 years Plant Retirement Costs - Unrecovered Plant, Texas 16.6 17.1 22 years Unamortized Loss on Reacquired Debt 6.6 7.4 24 years Rate Case Expense - Arkansas 5.2 0.8 5 years Other Regulatory Assets Approved for Recovery 7.9 11.3 various Total Regulatory Assets Currently Not Earning a Return 138.9 145.0 Total Regulatory Assets Approved for Recovery 176.1 166.4 Total Noncurrent Regulatory Assets $ 222.4 $ 230.8 (a) December 31, 2019 amount includes Arkansas jurisdiction. December 31, 2018 amount includes Arkansas and Louisiana jurisdictions. AEPTCo December 31, Remaining Recovery Period Regulatory Assets: 2019 2018 (in millions) Noncurrent Regulatory Assets Regulatory assets approved for recovery: Regulatory Assets Currently Not Earning a Return PJM/SPP Annual Formula Rate True Up $ 4.2 $ 12.9 2 years Total Regulatory Assets Approved for Recovery 4.2 12.9 Total Noncurrent Regulatory Assets $ 4.2 $ 12.9 OPCo December 31, Remaining Recovery Period Regulatory Assets: 2019 2018 (in millions) Current Regulatory Assets Under-recovered Fuel Costs - earns a return $ — $ 0.4 Total Current Regulatory Assets $ — $ 0.4 Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Not Earning a Return Other Regulatory Assets Pending Final Regulatory Approval $ 0.1 $ 1.0 Total Regulatory Assets Pending Final Regulatory Approval 0.1 1.0 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Ohio Distribution Decoupling 31.4 12.3 2 years Ohio Capacity Deferral — 57.8 Other Regulatory Assets Approved for Recovery — 0.9 Total Regulatory Assets Currently Earning a Return 31.4 71.0 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 167.3 181.5 11 years Unrealized Loss on Forward Commitments 103.6 100.2 13 years Smart Grid Costs 13.7 8.1 2 years Distribution Investment Rider 10.9 — 2 years Postemployment Benefits 7.6 7.9 4 years Unamortized Loss on Reacquired Debt 5.3 6.5 19 years Other Regulatory Assets Approved for Recovery 11.9 11.3 various Total Regulatory Assets Currently Not Earning a Return 320.3 315.5 Total Regulatory Assets Approved for Recovery 351.7 386.5 Total Noncurrent Regulatory Assets $ 351.8 $ 387.5 PSO December 31, Remaining Recovery Period 2019 2018 Regulatory Assets: (in millions) Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Earning a Return Oklaunion Power Station Accelerated Depreciation $ 27.4 $ 5.5 Total Regulatory Assets Currently Earning a Return 27.4 5.5 Regulatory Assets Currently Not Earning a Return Storm-Related Costs 7.2 — Other Regulatory Assets Pending Final Regulatory Approval — 0.5 Total Regulatory Assets Currently Not Earning a Return 7.2 0.5 Total Regulatory Assets Pending Final Regulatory Approval 34.6 6.0 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Unrecovered Plant 167.0 153.4 21 years Meter Replacement Costs 30.2 34.3 8 years Environmental Control Projects 27.8 29.2 21 years Storm-Related Costs 21.3 31.1 3 years Red Rock Generating Facility 8.4 8.6 37 years Other Regulatory Assets Approved for Recovery 0.6 0.5 various Total Regulatory Assets Currently Earning a Return 255.3 257.1 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 73.4 84.3 11 years Unamortized Loss on Reacquired Debt 6.5 4.3 15 years Peak Demand Reduction/Energy Efficiency — 6.3 Other Regulatory Assets Approved for Recovery 5.4 11.0 various Total Regulatory Assets Currently Not Earning a Return 85.3 105.9 Total Regulatory Assets Approved for Recovery 340.6 363.0 Total Noncurrent Regulatory Assets $ 375.2 $ 369.0
Regulatory Liabilities	SWEPCo December 31, Remaining Refund Period 2019 2018 Regulatory Liabilities: (in millions) Current Regulatory Liabilities Over-recovered Fuel Costs - pays a return (a) $ 13.6 $ 11.1 1 year Total Current Regulatory Liabilities $ 13.6 $ 11.1 Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits Regulatory liabilities pending final regulatory determination: Income Tax Related Regulatory Liabilities (b) Excess ADIT Associated with Certain Depreciable Property $ 297.0 $ 280.1 Excess ADIT that is Not Subject to Rate Normalization Requirements 22.7 26.9 Total Regulatory Liabilities Pending Final Regulatory Determination 319.7 307.0 Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs 453.4 437.8 (c) Other Regulatory Liabilities Approved for Payment 2.8 2.5 various Total Regulatory Liabilities Currently Paying a Return 456.2 440.3 Regulatory Liabilities Currently Not Paying a Return Peak Demand Reduction/Energy Efficiency 6.0 2.5 2 years Deferred Investment Tax Credits 3.1 4.5 12 years Other Regulatory Liabilities Approved for Payment 1.7 2.4 various Total Regulatory Liabilities Currently Not Paying a Return 10.8 9.4 Income Tax Related Regulatory Liabilities (b) Excess ADIT Associated with Certain Depreciable Property 339.4 370.5 (d) Excess ADIT that is Not Subject to Rate Normalization Requirements 27.8 54.3 1 year Income Taxes Subject to Flow Through (261.6 ) (258.5 ) 28 years Total Income Tax Related Regulatory Liabilities 105.6 166.3 Total Regulatory Liabilities Approved for Payment 572.6 616.0 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 892.3 $ 923.0 (a) December 31, 2019 amount includes Texas and Louisiana jurisdictions. December 31, 2018 amount includes Texas jurisdiction. (b) This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform. The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base. See “Federal Tax Reform” section of Note 12 for additional information. (c) Relieved as removal costs are incurred. (d) Refunded using ARAM. I&M December 31, Remaining Refund Period Regulatory Liabilities: 2019 2018 (in millions) Current Regulatory Liabilities Over-recovered Fuel Costs, Michigan - pays a return $ — $ 4.5 Over-recovered Fuel Costs, Indiana - does not pay a return 6.1 22.9 1 year Total Current Regulatory Liabilities $ 6.1 $ 27.4 Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits Regulatory liabilities pending final regulatory determination: Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property $ — $ 125.0 Excess ADIT that is Not Subject to Rate Normalization Requirements — 40.6 Total Regulatory Liabilities Pending Final Regulatory Determination — 165.6 Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs 166.7 182.5 (b) Other Regulatory Liabilities Approved for Payment 0.3 — various Total Regulatory Liabilities Currently Paying a Return 167.0 182.5 Regulatory Liabilities Currently Not Paying a Return Excess Nuclear Decommissioning Funding 1,236.0 828.5 (c) Spent Nuclear Fuel 43.6 42.9 (c) Deferred Investment Tax Credits 25.8 29.4 20 years PJM Costs and Off-system Sales Margin Sharing - Indiana 17.0 — 2 years PJM Transmission Enhancement Refund 11.8 29.1 6 years Deferred Gain on Sale of Rockport Unit 2 10.9 — 3 years Other Regulatory Liabilities Approved for Payment 24.9 24.0 various Total Regulatory Liabilities Currently Not Paying a Return 1,370.0 953.9 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 470.9 362.0 (d) Excess ADIT that is Not Subject to Rate Normalization Requirements 184.5 192.6 5 years Income Taxes Subject to Flow Through (301.0 ) (282.1 ) 19 years Total Income Tax Related Regulatory Liabilities 354.4 272.5 Total Regulatory Liabilities Approved for Payment 1,891.4 1,408.9 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 1,891.4 $ 1,574.5 (a) This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform. The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base. See “Federal Tax Reform” section of Note 12 for additional information. (b) Relieved as removal costs are incurred. (c) Relieved when plant is decommissioned. (d) Refunded using ARAM. AEP December 31, Remaining 2019 2018 Refund Period Current Regulatory Liabilities (in millions) Over-recovered Fuel Costs - pays a return $ 77.5 $ 35.7 1 year Over-recovered Fuel Costs - does not pay a return 9.1 22.9 1 year Total Current Regulatory Liabilities $ 86.6 $ 58.6 Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits Regulatory liabilities pending final regulatory determination: Regulatory Liabilities Currently Not Paying a Return Other Regulatory Liabilities Pending Final Regulatory Determination $ 0.2 $ 0.2 Total Regulatory Liabilities Currently Not Paying a Return 0.2 0.2 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 571.8 1,025.3 (b) Excess ADIT that is Not Subject to Rate Normalization Requirements 291.0 695.0 (c) (g) Total Income Tax Related Regulatory Liabilities 862.8 1,720.3 Total Regulatory Liabilities Pending Final Regulatory Determination 863.0 1,720.5 Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs 2,876.7 2,742.8 (d) Ohio Basic Transmission Cost Rider 37.2 68.8 2 years Excess Earnings 8.3 8.9 34 years Deferred Investment Tax Credits 6.2 8.7 41 years Other Regulatory Liabilities Approved for Payment 6.1 8.9 various Total Regulatory Liabilities Currently Paying a Return 2,934.5 2,838.1 Regulatory Liabilities Currently Not Paying a Return Excess Nuclear Decommissioning Funding 1,236.0 828.5 (e) Deferred Investment Tax Credits 215.3 204.9 43 years PJM Transmission Enhancement Refund 67.3 164.2 6 years Transition and Restoration Charges - Texas 50.5 46.0 10 years Spent Nuclear Fuel 43.6 42.9 (e) Ohio Enhanced Service Reliability Plan 29.7 43.1 2 years Virginia Transmission Rate Adjustment Clause 28.1 11.3 2 years Deferred Gain on Sale of Rockport Unit 2 27.2 — 3 years Peak Demand Reduction/Energy Efficiency 23.0 17.5 2 years Unrealized Gain on Forward Commitments 17.7 45.9 5 years Other Regulatory Liabilities Approved for Payment 70.0 73.5 various Total Regulatory Liabilities Currently Not Paying a Return 1,808.4 1,477.8 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 3,303.0 2,925.7 (f) Excess ADIT that is Not Subject to Rate Normalization Requirements 890.5 864.3 17 years Income Taxes Subject to Flow Through (1,341.8 ) (1,286.1 ) 56 years Total Income Tax Related Regulatory Liabilities 2,851.7 2,503.9 Total Regulatory Liabilities Approved for Payment 7,594.6 6,819.8 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 8,457.6 $ 8,540.3 (a) This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform. The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base. See “Federal Tax Reform” section of Note 12 for additional information. (b) Includes $275 million that will be refunded using ARAM upon receiving an order in the 2019 Texas Base Rate Case. See “2019 Texas Base Rate Case” section of Note 4 - Rate Matters for additional information. (c) Includes $71 million from a stipulation and settlement agreement filed in February 2020. See “2019 Texas Base Rate Case” section of Note 4 - Rate Matters for additional information. (d) Relieved as removal costs are incurred. (e) Relieved when plant is decommissioned. (f) Refunded using ARAM. PSO December 31, Remaining Refund Period 2019 2018 Regulatory Liabilities: (in millions) Current Regulatory Liabilities Over-recovered Fuel Costs - pays a return $ 63.9 $ 20.1 1 year Total Current Regulatory Liabilities $ 63.9 $ 20.1 Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs $ 286.8 $ 276.8 (b) Total Regulatory Liabilities Currently Paying a Return 286.8 276.8 Regulatory Liabilities Currently Not Paying a Return Deferred Investment Tax Credits 51.5 51.5 25 years Other Regulatory Liabilities Approved for Payment 4.7 2.5 various Total Regulatory Liabilities Currently Not Paying a Return 56.2 54.0 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 405.8 415.2 (c) Excess ADIT that is Not Subject to Rate Normalization Requirements 96.3 126.4 5 years Income Taxes Subject to Flow Through (7.9 ) (7.7 ) 24 years Total Income Tax Related Regulatory Liabilities 494.2 533.9 Total Regulatory Liabilities Approved for Payment 837.2 864.7 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 837.2 $ 864.7 (a) This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform. The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base. See “Federal Tax Reform” section of Note 12 for additional information. (b) Relieved as removal costs are incurred. (c) Refunded using ARAM. APCo December 31, Remaining Refund Period Regulatory Liabilities: 2019 2018 (in millions) Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits Regulatory liabilities pending final regulatory determination: Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property $ — $ 268.2 Excess ADIT that is Not Subject to Rate Normalization Requirements — 283.7 Total Regulatory Liabilities Pending Final Regulatory Determination — 551.9 Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs 635.3 618.3 (b) Deferred Investment Tax Credits 0.5 1.0 41 years Total Regulatory Liabilities Currently Paying a Return 635.8 619.3 Regulatory Liabilities Currently Not Paying a Return Virginia Transmission Rate Adjustment Clause 28.1 11.3 2 years PJM Transmission Enhancement Refund 19.5 47.7 6 years Unrealized Gain on Forward Commitments 9.3 34.7 5 years Consumer Rate Relief - West Virginia 5.4 8.8 1 year Other Regulatory Liabilities Approved for Payment 3.3 3.9 various Total Regulatory Liabilities Currently Not Paying a Return 65.6 106.4 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 718.9 453.5 (c) Excess ADIT that is Not Subject to Rate Normalization Requirements 210.7 84.5 9 years Income Taxes Subject to Flow Through (362.3 ) (365.9 ) 23 years Total Income Tax Related Regulatory Liabilities 567.3 172.1 Total Regulatory Liabilities Approved for Payment 1,268.7 897.8 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 1,268.7 $ 1,449.7 (a) This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform. The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base. See “Federal Tax Reform” section of Note 12 for additional information. (b) Relieved as removal costs are incurred. (c) Refunded using ARAM. AEPTCo December 31, Remaining Refund Period Regulatory Liabilities: 2019 2018 (in millions) Noncurrent Regulatory Liabilities Regulatory liabilities pending final regulatory determination: Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property $ — $ 73.9 Excess ADIT that is Not Subject to Rate Normalization Requirements — 4.5 Total Regulatory Liabilities Pending Final Regulatory Determination — 78.4 Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs 141.0 99.5 (b) Total Regulatory Liabilities Currently Paying a Return 141.0 99.5 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 535.7 453.4 (c) Excess ADIT that is Not Subject to Rate Normalization Requirements (35.4 ) (28.5 ) 9 years Income Taxes Subject to Flow Through (100.4 ) (81.5 ) 44 years Total Income Tax Related Regulatory Liabilities 399.9 343.4 Total Regulatory Liabilities Approved for Payment 540.9 442.9 Total Noncurrent Regulatory Liabilities $ 540.9 $ 521.3 (a) This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform. The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base. See “Federal Tax Reform” section of Note 12 for additional information. (b) Relieved as removal costs are incurred. (c) Refunded using ARAM. AEP Texas December 31, Remaining Refund Period Regulatory Liabilities: 2019 2018 (in millions) Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits Regulatory liabilities pending final regulatory determination: Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property $ 274.9 $ 277.1 (b) Excess ADIT that is Not Subject to Rate Normalization Requirements 87.1 141.4 (c) Total Regulatory Liabilities Pending Final Regulatory Determination 362.0 418.5 Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs 689.6 645.2 (d) Excess Earnings 5.8 6.3 12 years Advanced Metering Infrastructure Surcharge 4.3 8.5 1 year Total Regulatory Liabilities Currently Paying a Return 699.7 660.0 Regulatory Liabilities Currently Not Paying a Return Transition and Restoration Charges 50.5 46.0 10 years Deferred Investment Tax Credits 9.6 10.8 43 years Other Regulatory Liabilities Approved for Payment 4.8 — various Total Regulatory Liabilities Currently Not Paying a Return 64.9 56.8 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 236.5 251.8 (e) Income Taxes Subject to Flow Through (46.2 ) (42.8 ) 13 years Total Income Tax Related Regulatory Liabilities 190.3 209.0 Total Regulatory Liabilities Approved for Payment 954.9 925.8 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 1,316.9 $ 1,344.3 (a) This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform. The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base. See “Federal Tax Reform” section of Note 12 for additional information. (b) Will be refunded using ARAM upon receiving an order in the 2019 Texas Base Rate Case. See “2019 Texas Base Rate Case” section of Note 4 - Rate Matters for additional information. (c) Includes $71 million from a stipulation and settlement agreement filed in February 2020. See “2019 Texas Base Rate Case” section of Note 4 - Rate Matters for additional information. (d) Relieved as removal costs are incurred. (e) Refunded using ARAM. OPCo December 31, Remaining Refund Period 2019 2018 Regulatory Liabilities: (in millions) Current Regulatory Liabilities Over-recovered Fuel Costs - does not pay a return $ 2.8 $ — 1 year Total Current Regulatory Liabilities $ 2.8 $ — Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits Regulatory liabilities pending final regulatory determination: Regulatory Liabilities Currently Not Paying a Return Other Regulatory Liabilities Pending Final Regulatory Determination $ 0.2 $ 0.2 Total Regulatory Liabilities Pending Final Regulatory Determination 0.2 0.2 Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs 446.3 436.6 (b) Ohio Basic Transmission Cost Rider 37.2 68.8 2 years Other Regulatory Liabilities Approved for Payment 1.3 0.4 various Total Regulatory Liabilities Currently Paying a Return 484.8 505.8 Regulatory Liabilities Currently Not Paying a Return Ohio Enhanced Service Reliability Plan 29.7 43.1 2 years PJM Transmission Enhancement Refund 29.4 71.3 6 years Peak Demand Reduction/Energy Efficiency 19.7 14.9 2 years Distribution Investment Rider — 7.8 Other Regulatory Liabilities Approved for Payment 2.9 11.3 various Total Regulatory Liabilities Currently Not Paying a Return 81.7 148.4 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 341.6 350.5 (c) Excess ADIT that is Not Subject to Rate Normalization Requirements 252.3 279.1 9 years Income Taxes Subject to Flow Through (69.7 ) (62.8 ) 28 years Total Income Tax Related Regulatory Liabilities 524.2 566.8 Total Regulatory Liabilities Approved for Payment 1,090.7 1,221.0 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 1,090.9 $ 1,221.2 (a) This balance primarily represents regulatory liabilities for Excess ADIT as a result of the reduction in the corporate federal income tax rate from 35% to 21% related to the enactment of Tax Reform. The regulatory liability balance predominately pays a return due to the inclusion of Excess ADIT in rate base. See “Federal Tax Reform” section of Note 12 for additional information. (b) Relieved as removal costs are incurred. (c) Refunded using ARAM.

Commitments, Guarantees and C_2

Commitments, Guarantees and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2019
Contractual Commitments	Contractual Commitments - AEP Less Than 1 Year 2-3 Years 4-5 Years After 5 Years Total (in millions) Fuel Purchase Contracts (a) $ 1,047.0 $ 1,105.0 $ 234.4 $ 111.4 $ 2,497.8 Energy and Capacity Purchase Contracts 227.8 353.2 273.5 1,080.0 1,934.5 Total $ 1,274.8 $ 1,458.2 $ 507.9 $ 1,191.4 $ 4,432.3 Contractual Commitments - APCo Less Than 1 Year 2-3 Years 4-5 Years After 5 Years Total (in millions) Fuel Purchase Contracts (a) $ 415.3 $ 369.2 $ 4.6 $ 0.3 $ 789.4 Energy and Capacity Purchase Contracts 35.4 72.1 73.7 275.5 456.7 Total $ 450.7 $ 441.3 $ 78.3 $ 275.8 $ 1,246.1 Contractual Commitments - I&M Less Than 1 Year 2-3 Years 4-5 Years After 5 Years Total (in millions) Fuel Purchase Contracts (a) $ 299.8 $ 340.7 $ 211.6 $ 67.2 $ 919.3 Energy and Capacity Purchase Contracts 151.0 340.5 60.4 289.2 841.1 Total $ 450.8 $ 681.2 $ 272.0 $ 356.4 $ 1,760.4 Contractual Commitments - OPCo Less Than 1 Year 2-3 Years 4-5 Years After 5 Years Total (in millions) Energy and Capacity Purchase Contracts $ 29.0 $ 58.6 $ 58.8 $ 302.5 $ 448.9 Contractual Commitments - PSO Less Than 1 Year 2-3 Years 4-5 Years After 5 Years Total (in millions) Fuel Purchase Contracts (a) $ 52.3 $ 42.8 $ — $ — $ 95.1 Energy and Capacity Purchase Contracts 93.0 132.3 65.2 193.3 483.8 Total $ 145.3 $ 175.1 $ 65.2 $ 193.3 $ 578.9 Contractual Commitments - SWEPCo Less Than 1 Year 2-3 Years 4-5 Years After 5 Years Total (in millions) Fuel Purchase Contracts (a) $ 130.4 $ 147.4 $ 4.5 $ — $ 282.3 Energy and Capacity Purchase Contracts 14.0 12.5 8.4 8.4 43.3 Total $ 144.4 $ 159.9 $ 12.9 $ 8.4 $ 325.6 (a) Represents contractual commitments to purchase coal, natural gas, uranium and other consumables as fuel for electric generation along with related transportation of the fuel.
Maximum Future Payments for Letters of Credit Issued Under the Uncommitted Facilities	Company Amount Maturity (in millions) AEP $ 206.8 January 2020 to December 2020 AEP Texas 2.2 July 2020 OPCo 1.6 April 2020 to September 2020

Dispositions, Assets and Liab_2

Dispositions, Assets and Liabilities Held for Sale and Impairments (Tables)	12 Months Ended
	Dec. 31, 2019
Purchase Price Allocation of an Acquisition [Table Text Block]	Purchase Price Allocation of Sempra Renewables LLC at Acquisition Date - April 22nd, 2019 Assets: Liabilities and Equity: Net Purchase Price (in millions) Current Assets $ 8.8 Current Liabilities $ 12.9 Property, Plant and Equipment 238.1 Asset Retirement Obligations 5.7 Investment in Joint Ventures 404.0 Total Liabilities 18.6 Other Noncurrent Assets 82.9 Noncontrolling Interest 134.8 Total Assets $ 733.8 Liabilities and Noncontrolling Interest $ 153.4 $ 580.4

Benefit Plans (Tables)

Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2019
Health Care Trend Rates	December 31, Health Care Trend Rates 2019 2018 Initial 6.00 % 6.25 % Ultimate 4.50 % 5.00 % Year Ultimate Reached 2026 2024
Reconciliation of Changes in Benefit Obligations and Fair Value of Assets	SWEPCo Pension Plans OPEB 2019 2018 2019 2018 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 291.4 $ 314.6 $ 72.7 $ 80.3 Service Cost 8.6 9.3 0.8 0.9 Interest Cost 12.4 11.3 3.1 2.8 Actuarial (Gain) Loss 25.5 (19.2 ) 6.0 (5.9 ) Plan Amendments — — (0.8 ) — Benefit Payments (23.7 ) (24.6 ) (6.6 ) (7.7 ) Participant Contributions — — 2.2 2.3 Benefit Obligation as of December 31, $ 314.2 $ 291.4 $ 77.4 $ 72.7 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 281.0 $ 311.7 $ 98.5 $ 110.4 Actual Gain (Loss) on Plan Assets 39.5 (7.3 ) 23.1 (9.2 ) Company Contributions 0.1 1.2 — 2.7 Participant Contributions — — 2.2 2.3 Benefit Payments (23.7 ) (24.6 ) (6.6 ) (7.7 ) Fair Value of Plan Assets as of December 31, $ 296.9 $ 281.0 $ 117.2 $ 98.5 Funded (Underfunded) Status as of December 31, $ (17.3 ) $ (10.4 ) $ 39.8 $ 25.8 AEP Texas Pension Plans OPEB 2019 2018 2019 2018 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 409.3 $ 441.3 $ 95.9 $ 107.1 Service Cost 8.6 9.2 0.8 0.9 Interest Cost 17.5 16.0 4.0 3.8 Actuarial (Gain) Loss 40.1 (20.9 ) 3.9 (8.3 ) Plan Amendments — — (0.9 ) — Benefit Payments (34.3 ) (36.3 ) (8.8 ) (10.7 ) Participant Contributions — — 2.9 3.1 Benefit Obligation as of December 31, $ 441.2 $ 409.3 $ 97.8 $ 95.9 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 410.7 $ 455.9 $ 129.9 $ 147.3 Actual Gain (Loss) on Plan Assets 58.3 (9.3 ) 24.0 (14.6 ) Company Contributions 0.4 0.4 0.1 4.8 Participant Contributions — — 2.9 3.1 Benefit Payments (34.3 ) (36.3 ) (8.8 ) (10.7 ) Fair Value of Plan Assets as of December 31, $ 435.1 $ 410.7 $ 148.1 $ 129.9 Funded (Underfunded) Status as of December 31, $ (6.1 ) $ 1.4 $ 50.3 $ 34.0 PSO Pension Plans OPEB 2019 2018 2019 2018 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 253.8 $ 276.6 $ 62.3 $ 69.4 Service Cost 6.5 7.0 0.6 0.7 Interest Cost 10.6 9.9 2.6 2.5 Actuarial (Gain) Loss 16.8 (18.9 ) 3.8 (5.6 ) Plan Amendments — — (0.7 ) — Benefit Payments (20.2 ) (20.8 ) (5.9 ) (6.7 ) Participant Contributions — — 2.0 2.0 Benefit Obligation as of December 31, $ 267.5 $ 253.8 $ 64.7 $ 62.3 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 261.2 $ 287.8 $ 84.3 $ 95.5 Actual Gain (Loss) on Plan Assets 34.7 (5.9 ) 17.6 (9.2 ) Company Contributions 0.5 0.1 — 2.7 Participant Contributions — — 2.0 2.0 Benefit Payments (20.2 ) (20.8 ) (5.9 ) (6.7 ) Fair Value of Plan Assets as of December 31, $ 276.2 $ 261.2 $ 98.0 $ 84.3 Funded Status as of December 31, $ 8.7 $ 7.4 $ 33.3 $ 22.0 OPCo Pension Plans OPEB 2019 2018 2019 2018 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 453.9 $ 501.1 $ 129.5 $ 144.3 Service Cost 7.9 7.7 0.8 0.9 Interest Cost 19.1 17.7 5.5 5.1 Actuarial (Gain) Loss 40.5 (36.6 ) 4.9 (9.4 ) Plan Amendments — — (1.2 ) — Benefit Payments (33.6 ) (36.0 ) (13.5 ) (15.8 ) Participant Contributions — — 4.1 4.3 Medicare Subsidy — — 0.1 0.1 Benefit Obligation as of December 31, $ 487.8 $ 453.9 $ 130.2 $ 129.5 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 466.1 $ 509.1 $ 175.4 $ 198.5 Actual Gain (Loss) on Plan Assets 66.6 (7.0 ) 31.1 (11.6 ) Participant Contributions — — 4.1 4.3 Benefit Payments (33.6 ) (36.0 ) (13.5 ) (15.8 ) Fair Value of Plan Assets as of December 31, $ 499.1 $ 466.1 $ 197.1 $ 175.4 Funded Status as of December 31, $ 11.3 $ 12.2 $ 66.9 $ 45.9 AEP Pension Plans OPEB 2019 2018 2019 2018 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 4,810.3 $ 5,215.8 $ 1,194.5 $ 1,332.0 Service Cost 95.5 97.6 9.5 11.6 Interest Cost 204.4 187.8 50.5 47.4 Actuarial (Gain) Loss 493.6 (306.3 ) 58.8 (100.1 ) Plan Amendments 0.2 — (11.0 ) — Benefit Payments (367.2 ) (384.6 ) (113.0 ) (133.6 ) Participant Contributions — — 35.5 36.5 Medicare Subsidy — — 0.6 0.7 Benefit Obligation as of December 31, $ 5,236.8 $ 4,810.3 $ 1,225.4 $ 1,194.5 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 4,695.9 $ 5,174.1 $ 1,534.2 $ 1,732.5 Actual Gain (Loss) on Plan Assets 681.1 (104.9 ) 321.0 (118.3 ) Company Contributions (a) 5.6 11.3 4.1 17.1 Participant Contributions — — 35.5 36.5 Benefit Payments (367.2 ) (384.6 ) (113.0 ) (133.6 ) Fair Value of Plan Assets as of December 31, $ 5,015.4 $ 4,695.9 $ 1,781.8 $ 1,534.2 Funded (Underfunded) Status as of December 31, $ (221.4 ) $ (114.4 ) $ 556.4 $ 339.7 (a) AEP did not make contributions to the qualified pension plan in 2019 or 2018 . Contributions to the nonqualified pension plans were $6 million and $11 million for the years ended December 31, 2019 and 2018 , respectively. I&M Pension Plans OPEB 2019 2018 2019 2018 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 567.0 $ 624.3 $ 138.3 $ 153.5 Service Cost 13.4 13.6 1.4 1.6 Interest Cost 23.8 22.1 5.8 5.4 Actuarial (Gain) Loss 49.8 (53.9 ) 8.1 (10.6 ) Plan Amendments — — (1.5 ) — Benefit Payments (37.9 ) (39.1 ) (13.6 ) (16.2 ) Participant Contributions — — 4.4 4.5 Medicare Subsidy — — — 0.1 Benefit Obligation as of December 31, $ 616.1 $ 567.0 $ 142.9 $ 138.3 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 583.8 $ 636.7 $ 187.3 $ 211.1 Actual Gain (Loss) on Plan Assets 84.6 (13.8 ) 38.2 (12.1 ) Company Contributions — — — — Participant Contributions — — 4.4 4.5 Benefit Payments (37.9 ) (39.1 ) (13.6 ) (16.2 ) Fair Value of Plan Assets as of December 31, $ 630.5 $ 583.8 $ 216.3 $ 187.3 Funded Status as of December 31, $ 14.4 $ 16.8 $ 73.4 $ 49.0 APCo Pension Plans OPEB 2019 2018 2019 2018 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 603.1 $ 665.0 $ 205.5 $ 236.5 Service Cost 9.4 9.3 1.0 1.1 Interest Cost 25.2 23.5 8.7 8.2 Actuarial (Gain) Loss 52.9 (49.2 ) 4.7 (21.9 ) Plan Amendments — — (1.7 ) — Benefit Payments (43.4 ) (45.5 ) (20.8 ) (24.7 ) Participant Contributions — — 5.9 6.1 Medicare Subsidy — — 0.2 0.2 Benefit Obligation as of December 31, $ 647.2 $ 603.1 $ 203.5 $ 205.5 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 593.3 $ 651.7 $ 238.4 $ 273.4 Actual Gain (Loss) on Plan Assets 87.1 (12.9 ) 45.3 (18.7 ) Company Contributions — — 2.2 2.3 Participant Contributions — — 5.9 6.1 Benefit Payments (43.4 ) (45.5 ) (20.8 ) (24.7 ) Fair Value of Plan Assets as of December 31, $ 637.0 $ 593.3 $ 271.0 $ 238.4 Funded (Underfunded) Status as of December 31, $ (10.2 ) $ (9.8 ) $ 67.5 $ 32.9
Benefit Amounts Recognized on the Balance Sheets	Pension Plans OPEB December 31, OPCo 2019 2018 2019 2018 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ 11.7 $ 12.6 $ 66.9 $ 45.9 Deferred Credits and Other Noncurrent Liabilities – Accrued Long-term Benefit Liability (0.4 ) (0.4 ) — — Funded Status $ 11.3 $ 12.2 $ 66.9 $ 45.9 Pension Plans OPEB December 31, APCo 2019 2018 2019 2018 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ — $ — $ 92.0 $ 62.3 Other Current Liabilities – Accrued Short-term Benefit Liability — — (2.0 ) (2.1 ) Employee Benefits and Pension Obligations – Accrued Long-term Benefit Liability (10.2 ) (9.8 ) (22.5 ) (27.3 ) Funded (Underfunded) Status $ (10.2 ) $ (9.8 ) $ 67.5 $ 32.9 Pension Plans OPEB December 31, I&M 2019 2018 2019 2018 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ 15.8 $ 18.0 $ 73.4 $ 49.0 Deferred Credits and Other Noncurrent Liabilities – Accrued Long-term Benefit Liability (1.4 ) (1.2 ) — — Funded Status $ 14.4 $ 16.8 $ 73.4 $ 49.0 Pension Plans OPEB December 31, AEP Texas 2019 2018 2019 2018 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ — $ 5.2 $ 50.3 $ 34.0 Other Current Liabilities – Accrued Short-term Benefit Liability (0.4 ) (0.4 ) — — Deferred Credits and Other Noncurrent Liabilities – Accrued Long-term Benefit Liability (5.7 ) (3.4 ) — — Funded (Underfunded) Status $ (6.1 ) $ 1.4 $ 50.3 $ 34.0 Pension Plans OPEB December 31, AEP 2019 2018 2019 2018 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ — $ — $ 590.8 $ 392.2 Other Current Liabilities – Accrued Short-term Benefit Liability (6.1 ) (5.7 ) (2.6 ) (2.8 ) Employee Benefits and Pension Obligations – Accrued Long-term Benefit Liability (215.3 ) (108.7 ) (31.8 ) (49.7 ) Funded (Underfunded) Status $ (221.4 ) $ (114.4 ) $ 556.4 $ 339.7 Pension Plans OPEB December 31, PSO 2019 2018 2019 2018 (in millions) Employee Benefits and Pension Assets – Prepaid Benefit Costs $ 10.6 $ 9.7 $ 33.3 $ 22.0 Other Current Liabilities – Accrued Short-term Benefit Liability (0.1 ) (0.2 ) — — Deferred Credits and Other Noncurrent Liabilities – Accrued Long-term Benefit Liability (1.8 ) (2.1 ) — — Funded Status $ 8.7 $ 7.4 $ 33.3 $ 22.0 Pension Plans OPEB December 31, SWEPCo 2019 2018 2019 2018 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ — $ — $ 39.8 $ 25.8 Other Current Liabilities – Accrued Short-term Benefit Liability (0.1 ) (0.2 ) — — Employee Benefits and Pension Obligations – Accrued Long-term Benefit Liability (17.2 ) (10.2 ) — — Funded (Underfunded) Status $ (17.3 ) $ (10.4 ) $ 39.8 $ 25.8
Amounts Included in AOCI and Regulatory Assets	I&M Pension Plans OPEB December 31, 2019 2018 2019 2018 Components (in millions) Net Actuarial Loss $ 76.0 $ 80.6 $ 32.7 $ 54.7 Prior Service Credit — — (39.0 ) (47.4 ) Recorded as Regulatory Assets $ 73.7 $ 78.4 $ (6.2 ) $ 6.5 Deferred Income Taxes 0.5 0.5 — 0.2 Net of Tax AOCI 1.8 1.7 (0.1 ) 0.6 OPCo Pension Plans OPEB December 31, 2019 2018 2019 2018 Components (in millions) Net Actuarial Loss $ 178.7 $ 180.7 $ 17.2 $ 35.5 Prior Service Credit — — (28.6 ) (34.7 ) Recorded as Regulatory Assets $ 178.7 $ 180.7 $ (11.4 ) $ 0.8 PSO Pension Plans OPEB December 31, 2019 2018 2019 2018 Components (in millions) Net Actuarial Loss $ 73.0 $ 77.6 $ 18.2 $ 28.3 Prior Service Credit — — (17.8 ) (21.6 ) Recorded as Regulatory Assets $ 73.0 $ 77.6 $ 0.4 $ 6.7 APCo Pension Plans OPEB December 31, 2019 2018 2019 2018 Components (in millions) Net Actuarial Loss $ 168.3 $ 172.2 $ 28.8 $ 58.9 Prior Service Credit — — (41.6 ) (50.4 ) Recorded as Regulatory Assets $ 166.3 $ 169.6 $ (5.5 ) $ 2.6 Deferred Income Taxes 0.3 0.5 (1.5 ) 1.2 Net of Tax AOCI 1.7 2.1 (5.8 ) 4.7 AEP Texas Pension Plans OPEB December 31, 2019 2018 2019 2018 Components (in millions) Net Actuarial Loss $ 184.7 $ 182.0 $ 23.5 $ 38.0 Prior Service Credit — — (24.2 ) (29.5 ) Recorded as Regulatory Assets $ 172.2 $ 168.2 $ (0.2 ) $ 8.7 Deferred Income Taxes 2.7 2.9 (0.1 ) — Net of Tax AOCI 9.8 10.9 (0.4 ) (0.2 ) AEP Pension Plans OPEB December 31, 2019 2018 2019 2018 Components (in millions) Net Actuarial Loss $ 1,406.2 $ 1,355.2 $ 225.8 $ 419.8 Prior Service Cost (Credit) 0.2 — (285.7 ) (347.2 ) Recorded as Regulatory Assets $ 1,351.8 $ 1,267.9 $ (46.8 ) $ 52.5 Deferred Income Taxes 11.5 18.4 (2.7 ) 4.2 Net of Tax AOCI 43.1 68.9 (10.4 ) 15.9 SWEPCo Pension Plans OPEB December 31, 2019 2018 2019 2018 Components (in millions) Net Actuarial Loss $ 97.8 $ 97.4 $ 21.1 $ 33.9 Prior Service Credit — — (21.6 ) (26.2 ) Recorded as Regulatory Assets $ 97.8 $ 97.4 $ — $ 4.9 Deferred Income Taxes — — — 0.7 Net of Tax AOCI — — (0.5 ) 2.1
Components of Change in Amounts Included in AOCI and Regulatory Assets	AEP Texas Pension Plans OPEB 2019 2018 2019 2018 Components (in millions) Actuarial (Gain) Loss During the Year $ 7.6 $ 14.0 $ (12.7 ) $ 14.9 Amortization of Actuarial Loss (4.9 ) (7.2 ) (1.8 ) (0.8 ) Prior Service Credit — — (0.6 ) — Amortization of Prior Service Credit — — 5.9 5.9 Change for the Year Ended December 31, $ 2.7 $ 6.8 $ (9.2 ) $ 20.0 APCo Pension Plans OPEB 2019 2018 2019 2018 Components (in millions) Actuarial (Gain) Loss During the Year $ 3.1 $ 0.3 $ (26.4 ) $ 12.8 Amortization of Actuarial Loss (7.0 ) (10.6 ) (3.7 ) (1.9 ) Prior Service Credit — — (1.3 ) — Amortization of Prior Service Credit — — 10.1 10.0 Change for the Year Ended December 31, $ (3.9 ) $ (10.3 ) $ (21.3 ) $ 20.9 SWEPCo Pension Plans OPEB 2019 2018 2019 2018 Components (in millions) Actuarial (Gain) Loss During the Year $ 3.8 $ 5.5 $ (11.4 ) $ 9.8 Amortization of Actuarial Loss (3.4 ) (5.5 ) (1.4 ) (0.6 ) Prior Service Credit — — (0.6 ) — Amortization of Prior Service Credit — — 5.2 5.2 Change for the Year Ended December 31, $ 0.4 $ — $ (8.2 ) $ 14.4 AEP Pension Plans OPEB 2019 2018 2019 2018 Components (in millions) Actuarial (Gain) Loss During the Year $ 108.6 $ 88.8 $ (171.9 ) $ 120.4 Amortization of Actuarial Loss (57.6 ) (87.8 ) (22.1 ) (10.5 ) Prior Service (Credit) Cost 0.2 — (7.6 ) — Amortization of Prior Service Credit — — 69.1 69.1 Change for the Year Ended December 31, $ 51.2 $ 1.0 $ (132.5 ) $ 179.0 OPCo Pension Plans OPEB 2019 2018 2019 2018 Components (in millions) Actuarial (Gain) Loss During the Year $ 3.3 $ (0.9 ) $ (15.8 ) $ 14.0 Amortization of Actuarial Loss (5.3 ) (8.0 ) (2.5 ) (1.1 ) Prior Service Credit — — (0.8 ) — Amortization of Prior Service Credit — — 6.9 6.9 Change for the Year Ended December 31, $ (2.0 ) $ (8.9 ) $ (12.2 ) $ 19.8 PSO Pension Plans OPEB 2019 2018 2019 2018 Components (in millions) Actuarial (Gain) Loss During the Year $ (1.7 ) $ 3.2 $ (8.9 ) $ 9.0 Amortization of Actuarial Loss (2.9 ) (4.4 ) (1.2 ) (0.5 ) Prior Service Credit — — (0.5 ) — Amortization of Prior Service Credit — — 4.3 4.3 Change for the Year Ended December 31, $ (4.6 ) $ (1.2 ) $ (6.3 ) $ 12.8 I&M Pension Plans OPEB 2019 2018 2019 2018 Components (in millions) Actuarial (Gain) Loss During the Year $ 2.0 $ (4.5 ) $ (19.3 ) $ 13.9 Amortization of Actuarial Loss (6.6 ) (9.8 ) (2.7 ) (1.2 ) Prior Service Credit — — (1.0 ) — Amortization of Prior Service Credit — — 9.4 9.5 Change for the Year Ended December 31, $ (4.6 ) $ (14.3 ) $ (13.6 ) $ 22.2
Allocated Assets of Investments	Pension Plan OPEB December 31, Company 2019 2018 2019 2018 AEP Texas 8.7 % 8.7 % 8.3 % 8.5 % APCo 12.7 % 12.6 % 15.2 % 15.5 % I&M 12.6 % 12.4 % 12.1 % 12.2 % OPCo 10.0 % 9.9 % 11.1 % 11.4 % PSO 5.5 % 5.6 % 5.5 % 5.5 % SWEPCo 5.9 % 6.0 % 6.6 % 6.4 %
Accumulated Benefit Obligation	Accumulated Benefit Obligation AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Qualified Pension Plan $ 4,929.0 $ 417.5 $ 627.3 $ 586.3 $ 464.2 $ 248.9 $ 291.9 Nonqualified Pension Plans 69.7 3.6 0.2 0.6 0.1 1.6 1.3 Total as of December 31, 2019 $ 4,998.7 $ 421.1 $ 627.5 $ 586.9 $ 464.3 $ 250.5 $ 293.2 Accumulated Benefit Obligation AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Qualified Pension Plan $ 4,560.7 $ 393.2 $ 588.3 $ 536.3 $ 438.3 $ 238.0 $ 271.6 Nonqualified Pension Plans 64.9 3.6 0.2 0.6 0.2 2.2 1.2 Total as of December 31, 2018 $ 4,625.6 $ 396.8 $ 588.5 $ 536.9 $ 438.5 $ 240.2 $ 272.8
Underfunded Projected Benefit Obligation	AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Projected Benefit Obligation $ 5,236.8 $ 441.2 $ 647.2 $ 1.5 $ 0.4 $ 1.9 $ 314.2 Fair Value of Plan Assets 5,015.4 435.1 637.0 — — — 296.9 Underfunded Projected Benefit Obligation as of December 31, 2019 $ (221.4 ) $ (6.1 ) $ (10.2 ) $ (1.5 ) $ (0.4 ) $ (1.9 ) $ (17.3 ) AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Projected Benefit Obligation $ 4,810.3 $ 3.8 $ 603.1 $ 1.2 $ 0.4 $ 2.3 $ 291.4 Fair Value of Plan Assets 4,695.9 — 593.3 — — — 281.0 Underfunded Projected Benefit Obligation as of December 31, 2018 $ (114.4 ) $ (3.8 ) $ (9.8 ) $ (1.2 ) $ (0.4 ) $ (2.3 ) $ (10.4 )
Underfunded Accumulated Benefit Obligation	AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Accumulated Benefit Obligation $ 69.7 $ 3.6 $ 0.2 $ 0.6 $ 0.1 $ 1.6 $ 1.3 Fair Value of Plan Assets — — — — — — — Underfunded Accumulated Benefit Obligation as of December 31, 2019 $ (69.7 ) $ (3.6 ) $ (0.2 ) $ (0.6 ) $ (0.1 ) $ (1.6 ) $ (1.3 ) AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Accumulated Benefit Obligation $ 64.9 $ 3.6 $ 0.2 $ 0.6 $ 0.2 $ 2.2 $ 1.2 Fair Value of Plan Assets — — — — — — — Underfunded Accumulated Benefit Obligation as of December 31, 2018 $ (64.9 ) $ (3.6 ) $ (0.2 ) $ (0.6 ) $ (0.2 ) $ (2.2 ) $ (1.2 )
Estimated Contributions and Payments to the Pension and OPEB Plans	Company Pension Plans OPEB (in millions) AEP $ 6.1 $ 3.4 AEP Texas 0.4 0.1 APCo — 2.0 I&M — — OPCo — — PSO 0.1 — SWEPCo 0.1 —
Estimated Payments Expected to be Made by the Pension and OPEB Plans	Pension Plans AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) 2020 $ 378.1 $ 37.5 $ 45.8 $ 40.1 $ 36.2 $ 20.9 $ 24.0 2021 382.8 37.3 46.0 40.5 36.1 21.3 24.7 2022 380.5 35.9 45.7 42.5 35.7 21.2 25.2 2023 383.8 36.6 46.1 42.2 35.8 22.6 25.4 2024 382.9 36.3 46.8 42.8 34.0 21.5 25.8 Years 2025 to 2029, in Total 1,800.7 162.2 217.4 211.6 161.1 98.3 119.6 OPEB Benefit Payments AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) 2020 $ 126.3 $ 10.0 $ 22.5 $ 15.2 $ 14.8 $ 6.8 $ 7.5 2021 124.0 10.0 21.8 15.2 14.2 6.7 7.7 2022 125.2 10.4 21.6 15.5 14.4 6.9 8.0 2023 125.0 10.6 21.2 15.5 14.3 7.0 8.2 2024 124.6 10.7 21.1 15.4 14.1 7.1 8.4 Years 2025 to 2029, in Total 592.6 50.8 97.8 72.8 65.4 33.7 40.6 OPEB Medicare Subsidy Receipts AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) 2020 $ 0.2 $ — $ 0.1 $ — $ — $ — $ — 2021 0.3 — 0.2 — — — — 2022 0.3 — 0.2 — — — — 2023 0.3 — 0.1 — — — — 2024 0.3 — 0.1 — — — — Years 2025 to 2029, in Total 1.4 — 0.6 — — — —
Components of Net Periodic Benefit Cost	AEP Pension Plans OPEB Years Ended December 31, 2019 2018 2017 2019 2018 2017 (in millions) Service Cost $ 95.5 $ 97.6 $ 96.5 $ 9.5 $ 11.6 $ 11.2 Interest Cost 204.4 187.8 203.1 50.5 47.4 59.3 Expected Return on Plan Assets (296.0 ) (290.3 ) (284.8 ) (93.7 ) (102.2 ) (101.3 ) Amortization of Prior Service Cost (Credit) — — 1.0 (69.1 ) (69.1 ) (69.1 ) Amortization of Net Actuarial Loss 57.6 85.2 82.8 22.1 10.5 36.7 Settlements — 2.6 — — — — Net Periodic Benefit Cost (Credit) 61.5 82.9 98.6 (80.7 ) (101.8 ) (63.2 ) Capitalized Portion (38.6 ) (41.1 ) (39.9 ) (3.8 ) (4.9 ) 25.6 Net Periodic Benefit Cost (Credit) Recognized in Expense $ 22.9 $ 41.8 $ 58.7 $ (84.5 ) $ (106.7 ) $ (37.6 ) AEP Texas Pension Plans OPEB Years Ended December 31, 2019 2018 2017 2019 2018 2017 (in millions) Service Cost $ 8.6 $ 9.2 $ 8.6 $ 0.8 $ 0.9 $ 0.9 Interest Cost 17.5 16.0 17.1 4.0 3.8 4.9 Expected Return on Plan Assets (25.8 ) (25.6 ) (25.0 ) (7.8 ) (8.6 ) (8.8 ) Amortization of Prior Service Cost — — — (5.9 ) (5.9 ) (5.8 ) Amortization of Net Actuarial Loss 4.9 7.2 7.0 1.8 0.8 3.2 Net Periodic Benefit Cost (Credit) 5.2 6.8 7.7 (7.1 ) (9.0 ) (5.6 ) Capitalized Portion (4.5 ) (4.8 ) (4.0 ) (0.4 ) (0.5 ) 2.9 Net Periodic Benefit Cost (Credit) Recognized in Expense $ 0.7 $ 2.0 $ 3.7 $ (7.5 ) $ (9.5 ) $ (2.7 ) APCo Pension Plans OPEB Years Ended December 31, 2019 2018 2017 2019 2018 2017 (in millions) Service Cost $ 9.4 $ 9.3 $ 9.4 $ 1.0 $ 1.1 $ 1.1 Interest Cost 25.2 23.5 25.7 8.7 8.2 10.6 Expected Return on Plan Assets (37.4 ) (36.6 ) (35.8 ) (14.6 ) (16.0 ) (16.5 ) Amortization of Prior Service Cost (Credit) — — 0.2 (10.1 ) (10.0 ) (10.1 ) Amortization of Net Actuarial Loss 7.0 10.6 10.4 3.7 1.9 6.3 Net Periodic Benefit Cost (Credit) 4.2 6.8 9.9 (11.3 ) (14.8 ) (8.6 ) Capitalized Portion (4.0 ) (3.8 ) (4.0 ) (0.4 ) (0.5 ) 3.5 Net Periodic Benefit Cost (Credit) Recognized in Expense $ 0.2 $ 3.0 $ 5.9 $ (11.7 ) $ (15.3 ) $ (5.1 ) I&M Pension Plans OPEB Years Ended December 31, 2019 2018 2017 2019 2018 2017 (in millions) Service Cost $ 13.4 $ 13.6 $ 14.0 $ 1.4 $ 1.6 $ 1.6 Interest Cost 23.8 22.1 24.3 5.8 5.4 6.9 Expected Return on Plan Assets (36.8 ) (35.7 ) (34.6 ) (11.4 ) (12.3 ) (12.2 ) Amortization of Prior Service Cost (Credit) — — 0.2 (9.4 ) (9.5 ) (9.4 ) Amortization of Net Actuarial Loss 6.6 9.8 9.7 2.7 1.2 4.4 Net Periodic Benefit Cost (Credit) 7.0 9.8 13.6 (10.9 ) (13.6 ) (8.7 ) Capitalized Portion (3.4 ) (5.6 ) (5.5 ) (0.4 ) (0.7 ) 3.5 Net Periodic Benefit Cost (Credit) Recognized in Expense $ 3.6 $ 4.2 $ 8.1 $ (11.3 ) $ (14.3 ) $ (5.2 ) OPCo Pension Plans OPEB Years Ended December 31, 2019 2018 2017 2019 2018 2017 (in millions) Service Cost $ 7.9 $ 7.7 $ 7.5 $ 0.8 $ 0.9 $ 0.9 Interest Cost 19.1 17.7 19.4 5.5 5.1 6.7 Expected Return on Plan Assets (29.3 ) (28.8 ) (27.9 ) (10.8 ) (11.7 ) (11.9 ) Amortization of Prior Service Cost (Credit) — — 0.1 (6.9 ) (6.9 ) (6.9 ) Amortization of Net Actuarial Loss 5.3 8.0 7.8 2.5 1.1 4.3 Net Periodic Benefit Cost (Credit) 3.0 4.6 6.9 (8.9 ) (11.5 ) (6.9 ) Capitalized Portion (3.7 ) (3.6 ) (3.3 ) (0.4 ) (0.4 ) 3.3 Net Periodic Benefit Cost (Credit) Recognized in Expense $ (0.7 ) $ 1.0 $ 3.6 $ (9.3 ) $ (11.9 ) $ (3.6 ) PSO Pension Plans OPEB Years Ended December 31, 2019 2018 2017 2019 2018 2017 (in millions) Service Cost $ 6.5 $ 7.0 $ 6.4 $ 0.6 $ 0.7 $ 0.7 Interest Cost 10.6 9.9 10.7 2.6 2.5 3.2 Expected Return on Plan Assets (16.3 ) (16.1 ) (15.6 ) (5.1 ) (5.6 ) (5.6 ) Amortization of Prior Service Cost — — — (4.3 ) (4.3 ) (4.3 ) Amortization of Net Actuarial Loss 2.9 4.4 4.3 1.2 0.5 2.0 Net Periodic Benefit Cost (Credit) 3.7 5.2 5.8 (5.0 ) (6.2 ) (4.0 ) Capitalized Portion (2.4 ) (2.6 ) (2.1 ) (0.2 ) (0.3 ) 1.4 Net Periodic Benefit Cost (Credit) Recognized in Expense $ 1.3 $ 2.6 $ 3.7 $ (5.2 ) $ (6.5 ) $ (2.6 ) SWEPCo Pension Plans OPEB Years Ended December 31, 2019 2018 2017 2019 2018 2017 (in millions) Service Cost $ 8.6 $ 9.3 $ 8.7 $ 0.8 $ 0.9 $ 0.9 Interest Cost 12.4 11.3 12.3 3.1 2.8 3.6 Expected Return on Plan Assets (17.7 ) (17.3 ) (17.0 ) (5.9 ) (6.4 ) (6.3 ) Amortization of Prior Service Cost (Credit) — — 0.1 (5.2 ) (5.2 ) (5.2 ) Amortization of Net Actuarial Loss 3.4 5.1 4.9 1.4 0.6 2.3 Settlements — 0.4 — — — — Net Periodic Benefit Cost (Credit) 6.7 8.8 9.0 (5.8 ) (7.3 ) (4.7 ) Capitalized Portion (2.9 ) (3.1 ) (2.7 ) (0.3 ) (0.3 ) 1.4 Net Periodic Benefit Cost (Credit) Recognized in Expense $ 3.8 $ 5.7 $ 6.3 $ (6.1 ) $ (7.6 ) $ (3.3 )
Cost for Matching Contributions to the Retirement Savings Plans	Year Ended December 31, Company 2019 2018 2017 (in millions) AEP $ 76.4 $ 71.8 $ 74.6 AEP Texas 5.9 5.7 6.0 APCo 7.5 7.5 7.4 I&M 11.0 10.5 10.7 OPCo 6.6 6.3 6.1 PSO 4.6 4.5 5.0 SWEPCo 6.2 5.9 6.0
Benefit Obligations [Member]
Actuarial Assumptions	Pension Plans OPEB December 31, Assumption 2019 2018 2019 2018 Discount Rate 3.25 % 4.30 % 3.30 % 4.30 % Interest Crediting Rate 4.00 % 4.00 % NA NA NA Not applicable. Pension Plans December 31, Assumption – Rate of Compensation Increase (a) 2019 2018 AEP 4.95 % 4.85 % AEP Texas 5.00 % 4.95 % APCo 4.80 % 4.75 % I&M 4.95 % 4.90 % OPCo 5.15 % 5.00 % PSO 5.05 % 4.90 % SWEPCo 4.90 % 4.85 % (a) Rates are for base pay only. In addition, an amount is added to reflect target incentive compensation for exempt employees and overtime and incentive pay for nonexempt employees.
Benefit Costs [Member]
Actuarial Assumptions	Pension Plans OPEB Year Ended December 31, Assumption 2019 2018 2017 2019 2018 2017 Discount Rate 4.30 % 3.65 % 4.05 % 4.30 % 3.60 % 4.10 % Interest Crediting Rate 4.00 % 4.00 % 4.00 % NA NA NA Expected Return on Plan Assets 6.25 % 6.00 % 6.00 % 6.25 % 6.00 % 6.75 % NA Not applicable. Pension Plans Year Ended December 31, Assumption – Rate of Compensation Increase (a) 2019 2018 2017 AEP 4.95 % 4.85 % 4.80 % AEP Texas 5.00 % 4.95 % 4.90 % APCo 4.75 % 4.75 % 4.60 % I&M 4.95 % 4.90 % 4.85 % OPCo 5.20 % 5.00 % 4.95 % PSO 5.05 % 4.90 % 4.90 % SWEPCo 4.90 % 4.85 % 4.80 % (a) Rates are for base pay only. In addition, an amount is added to reflect target incentive compensation for exempt employees and overtime and incentive pay for nonexempt employees.
Pension Plans [Member]
Assets within Fair Value Hierarchy	Asset Class Level 1 Level 2 Level 3 Other Total Year End (in millions) Equities (a): Domestic $ 277.3 $ — $ — $ — $ 277.3 5.9 % International 384.1 — — — 384.1 8.2 % Options — 18.3 — — 18.3 0.4 % Common Collective Trusts (c) — — — 370.1 370.1 7.9 % Subtotal – Equities 661.4 18.3 — 370.1 1,049.8 22.4 % Fixed Income (a): United States Government and Agency Securities 0.2 1,512.5 — — 1,512.7 32.2 % Corporate Debt — 1,082.9 — — 1,082.9 23.0 % Foreign Debt — 221.6 — — 221.6 4.7 % State and Local Government — 28.2 — — 28.2 0.6 % Other – Asset Backed — 7.4 — — 7.4 0.2 % Subtotal – Fixed Income 0.2 2,852.6 — — 2,852.8 60.7 % Infrastructure (c) — — — 72.2 72.2 1.5 % Real Estate (c) — — — 220.4 220.4 4.7 % Alternative Investments (c) — — — 444.6 444.6 9.5 % Cash and Cash Equivalents (c) (0.4 ) 36.3 — 11.9 47.8 1.0 % Other – Pending Transactions and Accrued Income (b) — — — 8.3 8.3 0.2 % Total $ 661.2 $ 2,907.2 $ — $ 1,127.5 $ 4,695.9 100.0 % (a) Includes investment securities loaned to borrowers under the securities lending program. See the “Investments Held in Trust for Future Liabilities” section of Note 1 for additional information. (b) Amounts in “Other” column primarily represent accrued interest, dividend receivables and transactions pending settlement. (c) Amounts in “Other” column represent investments for which fair value is measured using net asset value per share. Asset Class Level 1 Level 2 Level 3 Other Total Year End Allocation (in millions) Equities (a): Domestic $ 387.8 $ — $ — $ — $ 387.8 7.8 % International 609.1 — — — 609.1 12.1 % Common Collective Trusts (c) — — — 547.3 547.3 10.9 % Subtotal – Equities 996.9 — — 547.3 1,544.2 30.8 % Fixed Income (a): United States Government and Agency Securities (5.8 ) 1,248.6 — — 1,242.8 24.8 % Corporate Debt — 1,143.7 — — 1,143.7 22.8 % Foreign Debt — 211.6 — — 211.6 4.2 % State and Local Government — 55.1 — — 55.1 1.1 % Other – Asset Backed — 3.6 — — 3.6 0.1 % Subtotal – Fixed Income (5.8 ) 2,662.6 — — 2,656.8 53.0 % Infrastructure (c) — — — 85.8 85.8 1.7 % Real Estate (c) — — — 239.4 239.4 4.8 % Alternative Investments (c) — — — 448.3 448.3 8.9 % Cash and Cash Equivalents (c) — 24.4 — 37.2 61.6 1.2 % Other – Pending Transactions and Accrued Income (b) — — — (20.7 ) (20.7 ) (0.4 )% Total $ 991.1 $ 2,687.0 $ — $ 1,337.3 $ 5,015.4 100.0 % (a) Includes investment securities loaned to borrowers under the securities lending program. See the “Investments Held in Trust for Future Liabilities” section of Note 1 for additional information. (b) Amounts in “Other” column primarily represent accrued interest, dividend receivables and transactions pending settlement. (c) Amounts in “Other” column represent investments for which fair value is measured using net asset value per share.
Other Postretirement Benefit Plans [Member]
Assets within Fair Value Hierarchy	Asset Class Level 1 Level 2 Level 3 Other Total Year End Allocation (in millions) Equities: Domestic $ 312.2 $ — $ — $ — $ 312.2 17.5 % International 251.5 — — — 251.5 14.1 % Common Collective Trusts (b) — — — 260.8 260.8 14.7 % Subtotal – Equities 563.7 — — 260.8 824.5 46.3 % Fixed Income: Common Collective Trust – Debt (b) — — — 177.6 177.6 10.0 % United States Government and Agency Securities (0.1 ) 214.4 — — 214.3 12.0 % Corporate Debt — 206.7 — — 206.7 11.6 % Foreign Debt — 35.5 — — 35.5 2.0 % State and Local Government 58.8 14.8 — — 73.6 4.1 % Other – Asset Backed — 0.2 — — 0.2 — % Subtotal – Fixed Income 58.7 471.6 — 177.6 707.9 39.7 % Trust Owned Life Insurance: International Equities — 60.2 — — 60.2 3.4 % United States Bonds — 151.6 — — 151.6 8.5 % Subtotal – Trust Owned Life Insurance — 211.8 — — 211.8 11.9 % Cash and Cash Equivalents (b) 26.7 — — 6.7 33.4 1.9 % Other – Pending Transactions and Accrued Income (a) — — — 4.2 4.2 0.2 % Total $ 649.1 $ 683.4 $ — $ 449.3 $ 1,781.8 100.0 % (a) Amounts in “Other” column primarily represent accrued interest, dividend receivables and transactions pending settlement. (b) Amounts in “Other” column represent investments for which fair value is measured using net asset value per share. Asset Class Level 1 Level 2 Level 3 Other Total Year End (in millions) Equities: Domestic $ 233.3 $ — $ — $ — $ 233.3 15.2 % International 185.9 — — — 185.9 12.1 % Options — 4.3 — — 4.3 0.3 % Common Collective Trusts (b) — — — 226.2 226.2 14.7 % Subtotal – Equities 419.2 4.3 — 226.2 649.7 42.3 % Fixed Income: Common Collective Trust – Debt (b) — — — 163.6 163.6 10.7 % United States Government and Agency Securities 0.2 181.5 — — 181.7 11.8 % Corporate Debt — 188.6 — — 188.6 12.3 % Foreign Debt — 35.0 — — 35.0 2.3 % State and Local Government 41.8 11.8 — — 53.6 3.5 % Other – Asset Backed — 0.2 — — 0.2 — % Subtotal – Fixed Income 42.0 417.1 — 163.6 622.7 40.6 % Trust Owned Life Insurance: International Equities — 49.4 — — 49.4 3.2 % United States Bonds — 154.4 — — 154.4 10.1 % Subtotal – Trust Owned Life Insurance — 203.8 — — 203.8 13.3 % Cash and Cash Equivalents (b) 54.4 — — 4.8 59.2 3.9 % Other – Pending Transactions and Accrued Income (a) — — — (1.2 ) (1.2 ) (0.1 )% Total $ 515.6 $ 625.2 $ — $ 393.4 $ 1,534.2 100.0 % (a) Amounts in “Other” column primarily represent accrued interest, dividend receivables and transactions pending settlement. (b) Amounts in “Other” column represent investments for which fair value is measured using net asset value per share.

Business Segments (Tables)

Business Segments (Tables)	12 Months Ended
	Dec. 31, 2019
Reportable Segment Information	State Transcos AEPTCo Parent Reconciling Adjustments AEPTCo Consolidated 2019 (in millions) Revenues from: External Customers $ 214.6 $ — $ — $ 214.6 Sales to AEP Affiliates 806.7 — — 806.7 Other Revenues 0.1 — — 0.1 Total Revenues $ 1,021.4 $ — $ — $ 1,021.4 Depreciation and Amortization $ 176.0 $ — $ — $ 176.0 Interest Income 1.3 123.8 (122.1 ) (a) 3.0 Allowance for Equity Funds Used During Construction 84.3 — — 84.3 Interest Expense 97.4 122.1 (122.1 ) (a) 97.4 Income Tax Expense 117.1 0.3 — 117.4 Net Income $ 438.6 $ 1.1 (b) $ — $ 439.7 Gross Property Additions $ 1,419.5 $ — $ — $ 1,419.5 Total Transmission Property $ 9,893.2 $ — $ — $ 9,893.2 Accumulated Depreciation and Amortization 402.3 — — 402.3 Total Transmission Property - Net $ 9,490.9 $ — $ — $ 9,490.9 Notes Receivable - Affiliated $ — $ 3,427.3 $ (3,427.3 ) (c) $ — Total Assets $ 9,865.0 $ 3,519.1 (d) $ (3,493.3 ) (e) $ 9,890.8 Total Long-Term Debt $ 3,465.0 $ 3,427.3 $ (3,465.0 ) (c) $ 3,427.3 State Transcos AEPTCo Parent Reconciling Adjustments AEPTCo Consolidated 2018 (in millions) Revenues from: External Customers $ 177.0 $ — $ — $ 177.0 Sales to AEP Affiliates 598.9 — — 598.9 Other Revenues 0.2 — — 0.2 Total Revenues $ 776.1 $ — $ — $ 776.1 Depreciation and Amortization $ 133.9 $ — $ — $ 133.9 Interest Income 1.3 104.6 (103.4 ) (a) 2.5 Allowance for Equity Funds Used During Construction 70.6 — — 70.6 Interest Expense 83.2 103.4 (103.4 ) (a) 83.2 Income Tax Expense 83.9 0.2 — 84.1 Net Income $ 314.9 $ 1.0 (b) $ — $ 315.9 Gross Property Additions $ 1,570.8 $ — $ — $ 1,570.8 Total Transmission Property $ 8,268.1 $ — $ — $ 8,268.1 Accumulated Depreciation and Amortization 271.9 — — 271.9 Total Transmission Property - Net $ 7,996.2 $ — $ — $ 7,996.2 Notes Receivable - Affiliated $ — $ 2,823.0 $ (2,823.0 ) (c) $ — Total Assets $ 8,406.8 $ 2,857.1 (d) $ (2,869.8 ) (e) $ 8,394.1 Total Long-Term Debt $ 2,850.0 $ 2,823.0 $ (2,850.0 ) (c) $ 2,823.0 ` State Transcos AEPTCo Parent Reconciling Adjustments AEPTCo Consolidated 2017 (in millions) Revenues from: External Customers $ 138.0 $ — $ — $ 138.0 Sales to AEP Affiliates 568.1 — — 568.1 Other 0.8 — — 0.8 Total Revenues $ 706.9 $ — $ — $ 706.9 Depreciation and Amortization $ 95.7 $ — $ — $ 95.7 Interest Income 0.7 82.9 (82.4 ) (a) 1.2 Allowance for Equity Funds Used During Construction 49.0 — — 49.0 Interest Expense 70.2 82.4 (82.4 ) (a) 70.2 Income Tax Expense (Benefit) 142.0 0.2 — 142.2 Net Income (Loss) $ 270.4 $ 0.3 (b) $ — $ 270.7 Gross Property Additions $ 1,522.5 $ — $ — $ 1,522.5 Total Assets $ 7,086.9 $ 2,590.1 (d) $ (2,594.9 ) (e) $ 7,082.1 (a) Elimination of intercompany interest income/interest expense on affiliated debt arrangement. (b) Includes elimination of AEPTCo Parent’s equity earnings in the State Transcos. (c) Elimination of intercompany debt. (d) Includes elimination of AEPTCo Parent’s investments in the State Transcos. (e) Primarily relates to elimination of Notes Receivable from the State Transcos. Vertically Integrated Utilities Transmission and Distribution Utilities AEP Transmission Holdco Generation & Marketing Corporate and Other (a) Reconciling Adjustments Consolidated (in millions) 2019 Revenues from: External Customers $ 9,245.7 $ 4,319.0 $ 260.2 $ 1,721.8 $ 14.7 $ — $ 15,561.4 Other Operating Segments 121.4 163.5 813.0 135.8 81.1 (1,314.8 ) — Total Revenues $ 9,367.1 $ 4,482.5 $ 1,073.2 $ 1,857.6 $ 95.8 $ (1,314.8 ) $ 15,561.4 Asset Impairments and Other Related Charges $ 92.9 $ 32.5 $ — $ 31.0 $ — $ — $ 156.4 Depreciation and Amortization 1,447.0 789.5 183.4 69.5 0.6 24.5 (b) 2,514.5 Interest Expense 568.3 243.3 103.3 30.0 193.7 (66.1 ) (b) 1,072.5 Income Tax Expense (Benefit) (97.7 ) (25.2 ) 136.2 (53.8 ) 27.6 — (12.9 ) Equity Earnings (Loss) of Unconsolidated Subsidiaries 3.0 — 72.8 (3.8 ) 0.1 — 72.1 Net Income (Loss) $ 985.6 $ 451.0 $ 520.1 $ 104.1 $ (141.0 ) $ — $ 1,919.8 Gross Property Additions $ 2,437.4 $ 2,074.3 $ 1,458.9 $ 1,005.1 $ 14.5 $ (20.4 ) $ 6,969.8 Total Property, Plant and Equipment $ 47,323.7 $ 19,773.3 $ 10,334.0 $ 1,650.8 $ 418.4 $ (354.5 ) (b) $ 79,145.7 Accumulated Depreciation and Amortization 14,580.4 3,911.2 418.9 99.0 184.5 (186.4 ) (b) 19,007.6 Total Property, Plant and Equipment – Net $ 32,743.3 $ 15,862.1 $ 9,915.1 $ 1,551.8 $ 233.9 $ (168.1 ) (b) $ 60,138.1 Total Assets $ 41,228.8 $ 18,757.5 $ 11,143.5 $ 3,123.8 $ 5,440.0 (c) $ (3,801.3 ) (b) (d) $ 75,892.3 Investments in Equity Method Investees $ 41.7 $ 2.5 $ 787.5 $ 459.5 $ 65.4 $ — $ 1,356.6 Long-term Debt Due Within One Year: Affiliated $ 20.0 $ — $ — $ — $ — $ (20.0 ) $ — Nonaffiliated 704.7 392.2 — — 501.8 (e) — 1,598.7 Long-term Debt: Affiliated 39.0 — — — — (39.0 ) — Nonaffiliated 12,162.0 6,248.1 3,593.8 — 3,122.9 (e) — 25,126.8 Total Long-term Debt $ 12,925.7 $ 6,640.3 $ 3,593.8 $ — $ 3,624.7 $ (59.0 ) $ 26,725.5 Vertically Integrated Utilities Transmission and Distribution Utilities AEP Transmission Holdco Generation & Marketing Corporate and Other (a) Reconciling Adjustments Consolidated (in millions) 2018 Revenues from: External Customers $ 9,556.7 $ 4,552.3 $ 248.6 $ 1,818.1 $ 20.0 $ — $ 16,195.7 Other Operating Segments 88.8 100.8 555.5 122.2 75.1 (942.4 ) — Total Revenues $ 9,645.5 $ 4,653.1 $ 804.1 $ 1,940.3 $ 95.1 $ (942.4 ) $ 16,195.7 Asset Impairments and Other Related Charges $ 3.4 $ — $ — $ 47.7 $ 19.5 $ — $ 70.6 Depreciation and Amortization 1,316.2 734.1 137.8 41.0 0.4 57.1 (b) 2,286.6 Interest Expense 567.8 248.1 90.7 14.9 122.6 (59.7 ) (b) 984.4 Income Tax Expense (Benefit) 5.7 42.4 95.3 (49.2 ) 21.1 — 115.3 Equity Earnings of Unconsolidated Subsidiaries 2.7 — 68.7 0.5 1.2 — 73.1 Net Income (Loss) $ 995.5 $ 527.4 $ 373.0 $ 134.7 $ (99.3 ) $ — $ 1,931.3 Gross Property Additions $ 2,282.2 $ 2,162.4 $ 1,614.1 $ 289.7 $ 16.3 $ (39.2 ) $ 6,325.5 Total Property, Plant and Equipment $ 45,365.1 $ 18,126.7 $ 8,659.5 $ 893.3 $ 395.2 $ (354.6 ) (b) $ 73,085.2 Accumulated Depreciation and Amortization 13,822.5 3,833.7 282.8 47.0 186.6 (186.5 ) (b) 17,986.1 Total Property, Plant and Equipment – Net $ 31,542.6 $ 14,293.0 $ 8,376.7 $ 846.3 $ 208.6 $ (168.1 ) (b) $ 55,099.1 Total Assets $ 38,874.3 $ 17,083.4 $ 9,543.7 $ 1,979.7 $ 4,036.5 (c) $ (2,714.8 ) (b) (d) $ 68,802.8 Investments in Equity Method Investees $ 39.6 $ 2.9 $ 750.9 $ 26.7 $ 26.1 $ — $ 846.2 Long-term Debt Due Within One Year: Nonaffiliated $ 1,066.3 $ 549.1 $ 85.0 $ 0.1 $ (2.0 ) (e) $ — $ 1,698.5 Long-term Debt: Affiliated 50.0 — — 32.2 — (82.2 ) — Nonaffiliated 11,442.7 5,048.8 2,888.6 (0.3 ) 2,268.4 — 21,648.2 Total Long-term Debt $ 12,559.0 $ 5,597.9 $ 2,973.6 $ 32.0 $ 2,266.4 (e) $ (82.2 ) $ 23,346.7 Vertically Integrated Utilities Transmission and Distribution Utilities AEP Transmission Holdco Generation & Marketing Corporate and Other(a) Reconciling Adjustments Consolidated (in millions) 2017 Revenues from: External Customers $ 9,095.1 $ 4,328.9 $ 178.4 $ 1,771.4 $ 51.1 $ — $ 15,424.9 Other Operating Segments 96.9 90.4 588.3 103.7 69.7 (949.0 ) — Total Revenues $ 9,192.0 $ 4,419.3 $ 766.7 $ 1,875.1 $ 120.8 $ (949.0 ) $ 15,424.9 Asset Impairments and Other Related Charges $ 33.6 $ — $ — $ 53.5 $ — $ — $ 87.1 Depreciation and Amortization 1,142.5 667.5 102.2 24.2 0.3 60.5 (b) 1,997.2 Interest Expense 540.0 244.1 72.8 18.5 63.9 (44.3 ) (b) 895.0 Income Tax Expense 425.6 127.2 189.8 189.7 37.4 — 969.7 Equity Earnings (Loss) of Unconsolidated Subsidiaries $ (3.8 ) $ — $ 88.6 $ — $ (2.4 ) $ — $ 82.4 Net Income (Loss) $ 803.3 $ 636.4 $ 355.6 $ 166.0 $ (32.4 ) $ — $ 1,928.9 Gross Property Additions $ 2,343.2 $ 1,558.4 $ 1,542.8 $ 328.5 $ 15.6 $ (90.4 ) $ 5,698.1 Total Assets $ 37,579.7 $ 16,060.7 $ 8,141.8 $ 2,009.8 $ 3,959.1 (c) $ (3,022.0 ) (b) (d) $ 64,729.1 (a) Corporate and Other primarily includes the purchasing of receivables from certain AEP utility subsidiaries. This segment also includes Parent’s guarantee revenue received from affiliates, investment income, interest income, interest expense and other nonallocated costs. (b) Includes eliminations due to an intercompany finance lease. (c) Includes elimination of AEP Parent’s investments in wholly-owned subsidiary companies. (d) Reconciling Adjustments for Total Assets primarily include elimination of intercompany advances to affiliates and intercompany accounts receivable. (e) Amounts reflect the impact of fair value hedge accounting. See “Accounting for Fair Value Hedging Strategies” section of Note 10 for additional information.

Derivatives and Hedging (Tables

Derivatives and Hedging (Tables)	12 Months Ended
	Dec. 31, 2019
Notional Volume of Derivative Instruments	Notional Volume of Derivative Instruments December 31, 2019 Primary Risk Exposure Unit of Measure AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Commodity: Power MWhs 365.9 — 61.0 26.8 7.1 14.9 4.4 Natural Gas MMBtus 40.7 — — — — — 11.6 Heating Oil and Gasoline Gallons 6.9 1.8 1.1 0.6 1.4 0.7 0.9 Interest Rate USD $ 140.1 $ — $ — $ — $ — $ — $ — Interest Rate on Long-term Debt USD $ 625.0 $ — $ — $ — $ — $ — $ — December 31, 2018 Primary Risk Exposure Unit of Measure AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Commodity: Power MWhs 371.1 — 66.4 40.9 7.8 15.2 4.5 Natural Gas MMBtus 87.9 — 4.0 2.3 — — 15.2 Heating Oil and Gasoline Gallons 7.4 1.5 1.4 0.7 1.8 0.7 0.8 Interest Rate USD $ 37.7 $ — $ — $ — $ — $ — $ — Interest Rate on Long-term Debt USD $ 500.0 $ — $ — $ — $ — $ — $ —
Fair Value of Derivative Instruments	AEP Fair Value of Derivative Instruments December 31, 2019 Risk Management Contracts Hedging Contracts Gross Amounts of Risk Management Assets/ Liabilities Recognized Gross Amounts Offset in the Statement of Financial Position (b) Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position (c) Balance Sheet Location Commodity (a) Commodity (a) Interest Rate (a) (in millions) Current Risk Management Assets $ 513.9 $ 11.5 $ 6.5 $ 531.9 $ (359.1 ) $ 172.8 Long-term Risk Management Assets 290.8 11.0 12.6 314.4 (47.8 ) 266.6 Total Assets 804.7 22.5 19.1 846.3 (406.9 ) 439.4 Current Risk Management Liabilities 424.5 72.3 — 496.8 (382.5 ) 114.3 Long-term Risk Management Liabilities 244.5 75.7 — 320.2 (58.4 ) 261.8 Total Liabilities 669.0 148.0 — 817.0 (440.9 ) 376.1 Total MTM Derivative Contract Net Assets (Liabilities) $ 135.7 $ (125.5 ) $ 19.1 $ 29.3 $ 34.0 $ 63.3 December 31, 2018 Risk Management Contracts Hedging Contracts Gross Amounts of Risk Management Assets/ Liabilities Recognized Gross Amounts Offset in the Statement of Financial Position (b) Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position (c) Balance Sheet Location Commodity (a) Commodity (a) Interest Rate (a) (in millions) Current Risk Management Assets $ 397.5 $ 28.5 $ — $ 426.0 $ (263.2 ) $ 162.8 Long-term Risk Management Assets 276.4 16.0 — 292.4 (38.4 ) 254.0 Total Assets 673.9 44.5 — 718.4 (301.6 ) 416.8 Current Risk Management Liabilities 293.8 13.2 2.0 309.0 (254.0 ) 55.0 Long-term Risk Management Liabilities 225.7 56.1 15.4 297.2 (33.8 ) 263.4 Total Liabilities 519.5 69.3 17.4 606.2 (287.8 ) 318.4 Total MTM Derivative Contract Net Assets (Liabilities) $ 154.4 $ (24.8 ) $ (17.4 ) $ 112.2 $ (13.8 ) $ 98.4 AEP Texas Fair Value of Derivative Instruments December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ — $ — $ — Long-term Risk Management Assets — — — Total Assets — — — Current Risk Management Liabilities — — — Long-term Risk Management Liabilities — — — Total Liabilities — — — Total MTM Derivative Contract Net Assets $ — $ — $ — December 31, 2018 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ — $ — $ — Long-term Risk Management Assets — — — Total Assets — — — Current Risk Management Liabilities 0.7 (0.5 ) 0.2 Long-term Risk Management Liabilities — — — Total Liabilities 0.7 (0.5 ) 0.2 Total MTM Derivative Contract Net Assets (Liabilities) $ (0.7 ) $ 0.5 $ (0.2 ) APCo Fair Value of Derivative Instruments December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ 124.4 $ (85.0 ) $ 39.4 Long-term Risk Management Assets 0.9 (0.8 ) 0.1 Total Assets 125.3 (85.8 ) 39.5 Current Risk Management Liabilities 86.2 (84.3 ) 1.9 Long-term Risk Management Liabilities 0.7 (0.7 ) — Total Liabilities 86.9 (85.0 ) 1.9 Total MTM Derivative Contract Net Assets (Liabilities) $ 38.4 $ (0.8 ) $ 37.6 December 31, 2018 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ 114.4 $ (57.2 ) $ 57.2 Long-term Risk Management Assets 3.1 (2.2 ) 0.9 Total Assets 117.5 (59.4 ) 58.1 Current Risk Management Liabilities 56.7 (56.3 ) 0.4 Long-term Risk Management Liabilities 2.4 (2.2 ) 0.2 Total Liabilities 59.1 (58.5 ) 0.6 Total MTM Derivative Contract Net Assets (Liabilities) $ 58.4 $ (0.9 ) $ 57.5 I&M Fair Value of Derivative Instruments December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ 66.9 $ (57.1 ) $ 9.8 Long-term Risk Management Assets 0.5 (0.4 ) 0.1 Total Assets 67.4 (57.5 ) 9.9 Current Risk Management Liabilities 55.2 (54.7 ) 0.5 Long-term Risk Management Liabilities 0.4 (0.4 ) — Total Liabilities 55.6 (55.1 ) 0.5 Total MTM Derivative Contract Net Assets (Liabilities) $ 11.8 $ (2.4 ) $ 9.4 December 31, 2018 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ 50.4 $ (41.8 ) $ 8.6 Long-term Risk Management Assets 2.0 (1.4 ) 0.6 Total Assets 52.4 (43.2 ) 9.2 Current Risk Management Liabilities 41.1 (40.8 ) 0.3 Long-term Risk Management Liabilities 1.6 (1.5 ) 0.1 Total Liabilities 42.7 (42.3 ) 0.4 Total MTM Derivative Contract Net Assets (Liabilities) $ 9.7 $ (0.9 ) $ 8.8 OPCo Fair Value of Derivative Instruments December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ — $ — $ — Long-term Risk Management Assets — — — Total Assets — — — Current Risk Management Liabilities 7.3 — 7.3 Long-term Risk Management Liabilities 96.3 — 96.3 Total Liabilities 103.6 — 103.6 Total MTM Derivative Contract Net Liabilities $ (103.6 ) $ — $ (103.6 ) December 31, 2018 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ — $ — $ — Long-term Risk Management Assets — — — Total Assets — — — Current Risk Management Liabilities 6.4 (0.6 ) 5.8 Long-term Risk Management Liabilities 93.8 — 93.8 Total Liabilities 100.2 (0.6 ) 99.6 Total MTM Derivative Contract Net Assets (Liabilities) $ (100.2 ) $ 0.6 $ (99.6 ) PSO Fair Value of Derivative Instruments December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ 16.3 $ (0.5 ) $ 15.8 Long-term Risk Management Assets — — — Total Assets 16.3 (0.5 ) 15.8 Current Risk Management Liabilities 0.5 (0.5 ) — Long-term Risk Management Liabilities — — — Total Liabilities 0.5 (0.5 ) — Total MTM Derivative Contract Net Assets $ 15.8 $ — $ 15.8 December 31, 2018 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ 10.9 $ (0.5 ) $ 10.4 Long-term Risk Management Assets — — — Total Assets 10.9 (0.5 ) 10.4 Current Risk Management Liabilities 1.7 (0.7 ) 1.0 Long-term Risk Management Liabilities — — — Total Liabilities 1.7 (0.7 ) 1.0 Total MTM Derivative Contract Net Assets $ 9.2 $ 0.2 $ 9.4 SWEPCo Fair Value of Derivative Instruments December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ 6.5 $ (0.1 ) $ 6.4 Long-term Risk Management Assets — — — Total Assets 6.5 (0.1 ) 6.4 Current Risk Management Liabilities 2.0 (0.1 ) 1.9 Long-term Risk Management Liabilities 3.1 — 3.1 Total Liabilities 5.1 (0.1 ) 5.0 Total MTM Derivative Contract Net Assets $ 1.4 $ — $ 1.4 December 31, 2018 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts - in the Statement of Presented in the Statement Balance Sheet Location Commodity (a) Financial Position (b) of Financial Position (c) (in millions) Current Risk Management Assets $ 5.6 $ (0.8 ) $ 4.8 Long-term Risk Management Assets — — — Total Assets 5.6 (0.8 ) 4.8 Current Risk Management Liabilities 1.5 (1.1 ) 0.4 Long-term Risk Management Liabilities 2.2 — 2.2 Total Liabilities 3.7 (1.1 ) 2.6 Total MTM Derivative Contract Net Assets $ 1.9 $ 0.3 $ 2.2 (a) Derivative instruments within these categories are reported gross. These instruments are subject to master netting agreements and are presented on the balance sheets on a net basis in accordance with the accounting guidance for “Derivatives and Hedging.” (b) Amounts include counterparty netting of risk management and hedging contracts and associated cash collateral in accordance with the accounting guidance for “Derivatives and Hedging.” (c) All derivative contracts subject to a master netting arrangement or similar agreement are offset in the statement of financial position.
Amount of Gain (Loss) Recognized on Risk Management Contracts	Amount of Gain (Loss) Recognized on Risk Management Contracts Year Ended December 31, 2019 Location of Gain (Loss) AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Vertically Integrated Utilities Revenues $ 0.7 $ — $ — $ — $ — $ — $ — Generation & Marketing Revenues 25.1 — — — — — — Electric Generation, Transmission and Distribution Revenues — — 0.1 0.5 — — 0.1 Purchased Electricity for Resale 1.9 — 1.6 0.1 — — — Other Operation (0.8 ) (0.2 ) (0.1 ) (0.1 ) (0.2 ) (0.1 ) (0.1 ) Maintenance (0.8 ) (0.2 ) (0.2 ) (0.1 ) (0.2 ) (0.1 ) (0.1 ) Regulatory Assets (a) (3.7 ) 0.7 0.3 0.3 (3.7 ) 1.2 (1.5 ) Regulatory Liabilities (a) 102.6 — 2.4 24.5 10.1 34.6 26.6 Total Gain on Risk Management Contracts $ 125.0 $ 0.3 $ 4.1 $ 25.2 $ 6.0 $ 35.6 $ 25.0 Amount of Gain (Loss) Recognized on Risk Management Contracts Year Ended December 31, 2018 Location of Gain (Loss) AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Vertically Integrated Utilities Revenues $ (10.4 ) $ — $ — $ — $ — $ — $ — Generation & Marketing Revenues 38.9 — — — — — — Electric Generation, Transmission and Distribution Revenues — — (1.9 ) (8.2 ) — — 0.1 Purchased Electricity for Resale 8.6 — 7.6 0.8 — — — Other Operation 1.7 0.4 0.2 0.2 0.3 0.2 0.2 Maintenance 1.9 0.4 0.4 0.2 0.4 0.2 0.2 Regulatory Assets (a) 27.9 (0.7 ) (0.7 ) 7.1 24.9 (1.1 ) (1.2 ) Regulatory Liabilities (a) 222.7 (0.5 ) 135.5 11.6 — 37.3 11.9 Total Gain (Loss) on Risk Management Contracts $ 291.3 $ (0.4 ) $ 141.1 $ 11.7 $ 25.6 $ 36.6 $ 11.2 Amount of Gain (Loss) Recognized on Risk Management Contracts Year Ended December 31, 2017 Location of Gain (Loss) AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Vertically Integrated Utilities Revenues $ 6.1 $ — $ — $ — $ — $ — $ — Generation & Marketing Revenues 42.8 — — — — — — Electric Generation, Transmission and Distribution Revenues — — 0.6 5.3 — — 0.1 Purchased Electricity for Resale 5.6 — 2.0 0.6 — — — Other Operation 0.8 0.1 0.1 0.1 0.1 0.1 0.1 Maintenance 0.7 0.2 0.1 0.1 0.1 0.1 0.1 Regulatory Assets (a) (29.4 ) — — (7.4 ) (22.0 ) — 0.3 Regulatory Liabilities (a) 109.4 0.1 40.4 15.9 — 24.8 24.3 Total Gain (Loss) on Risk Management Contracts $ 136.0 $ 0.4 $ 43.2 $ 14.6 $ (21.8 ) $ 25.0 $ 24.9 (a) Represents realized and unrealized gains and losses subject to regulatory accounting treatment recorded as either current or noncurrent on the balance sheets.
Impact of Fair Value Hedges on Balance Sheet	Carrying Amount of the Hedged Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Assets/(Liabilities) December 31, 2019 December 31, 2018 December 31, 2019 December 31, 2018 (in millions) Long-term Debt (a) $ (510.8 ) $ (478.3 ) $ (14.5 ) $ 17.4 (a) Amounts included on the balance sheets within Long-term Debt Due within One Year and Long-term Debt, respectively.
Gain (Loss) on Hedging Instruments	Twelve Months Ended December 31, 2019 2018 2017 (in millions) Gain (Loss) on Interest Rate Contracts: Gain (Loss) on Fair Value Hedging Instruments (a) $ 31.9 $ (11.3 ) $ (4.8 ) Gain (Loss) on Fair Value Portion of Long-term Debt (a) (31.9 ) 11.3 4.8 (a) Gain (Loss) is included in Interest Expense on the statements of income.
Impact of Cash Flow Hedges on the Balance Sheet	Impact of Cash Flow Hedges on the Registrant Subsidiaries’ Balance Sheets December 31, 2019 December 31, 2018 Interest Rate Expected to be Expected to be Reclassified to Reclassified to Net Income During Net Income During AOCI Gain (Loss) the Next AOCI Gain (Loss) the Next Company Net of Tax Twelve Months Net of Tax Twelve Months (in millions) AEP Texas $ (3.4 ) $ (1.1 ) $ (4.4 ) $ (1.1 ) APCo 0.9 0.9 1.8 0.9 I&M (9.9 ) (1.6 ) (11.5 ) (1.6 ) OPCo — — 1.0 1.0 PSO 1.1 1.0 2.1 1.0 SWEPCo (1.8 ) (1.5 ) (3.3 ) (1.5 ) Impact of Cash Flow Hedges on AEP’s Balance Sheets December 31, 2019 December 31, 2018 Commodity Interest Rate Commodity Interest Rate (in millions) AOCI Gain (Loss) Net of Tax $ (103.5 ) $ (11.5 ) (a) $ (23.0 ) $ (12.6 ) Portion Expected to be Reclassed to Net Income During the Next Twelve Months (51.7 ) (2.1 ) 10.4 (1.1 ) (a) Includes $4 million related to AEP's investment in joint venture wind farms acquired as part of the purchase of Sempra Renewables LLC. See “Sempra Renewables LLC” section of Note 17 for additional information.
Liabilities Subject to Cross Default Provisions	December 31, 2019 Liabilities for Additional Contracts with Cross Settlement Default Provisions Liability if Cross Prior to Contractual Amount of Cash Default Provision Company Netting Arrangements Collateral Posted is Triggered (in millions) AEP $ 267.3 $ 3.7 $ 246.7 APCo 2.3 — 0.4 I&M 1.3 — 0.2 SWEPCo 5.1 — 5.1 December 31, 2018 Liabilities for Additional Contracts with Cross Settlement Default Provisions Liability if Cross Prior to Contractual Amount of Cash Default Provision Company Netting Arrangements Collateral Posted is Triggered (in millions) AEP $ 225.5 $ 1.8 $ 181.0 APCo 0.9 — — I&M 0.5 — — SWEPCo 2.3 — 2.3

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2019
Book Values and Fair Values of Long-term Debt	December 31, 2019 2018 Company Book Value Fair Value Book Value Fair Value (in millions) AEP (a) $ 26,725.5 $ 30,172.0 $ 23,346.7 $ 24,093.9 AEP Texas 4,558.4 4,981.5 3,881.3 3,964.6 AEPTCo 3,427.3 3,868.0 2,823.0 2,782.4 APCo 4,363.8 5,253.1 4,062.6 4,473.3 I&M 3,050.2 3,453.8 3,035.4 3,070.2 OPCo 2,082.0 2,554.3 1,716.6 1,919.7 PSO 1,386.2 1,603.3 1,287.0 1,361.9 SWEPCo 2,655.6 2,927.9 2,713.4 2,670.2 (a) The fair value amount includes debt related to AEP’s Equity Units issued in March 2019 and had a fair value of $871 million as of December 31, 2019 . See “Equity Units” section of Note 14 for additional information.
Other Temporary Investments	December 31, 2019 Gross Gross Unrealized Unrealized Fair Other Temporary Investments Cost Gains Losses Value (in millions) Restricted Cash and Other Cash Deposits (a) $ 214.7 $ — $ — $ 214.7 Fixed Income Securities – Mutual Funds (b) 123.2 0.1 — 123.3 Equity Securities – Mutual Funds 29.2 21.3 — 50.5 Total Other Temporary Investments $ 367.1 $ 21.4 $ — $ 388.5 December 31, 2018 Gross Gross Unrealized Unrealized Fair Other Temporary Investments Cost Gains Losses Value (in millions) Restricted Cash and Other Cash Deposits (a) $ 230.6 $ — $ — $ 230.6 Fixed Income Securities – Mutual Funds (b) 106.6 — (2.3 ) 104.3 Equity Securities – Mutual Funds 17.8 16.4 — 34.2 Total Other Temporary Investments $ 355.0 $ 16.4 $ (2.3 ) $ 369.1 (a) Primarily represents amounts held for the repayment of debt. (b) Primarily short and intermediate maturities which may be sold and do not contain maturity dates.
Debt and Equity Securities Within Other Temporary Investments	Years Ended December 31, 2019 2018 2017 (in millions) Proceeds from Investment Sales $ 21.2 $ — $ — Purchases of Investments 45.0 3.1 14.2 Gross Realized Gains on Investment Sales — — — Gross Realized Losses on Investment Sales 0.4 — —
Nuclear Trust Fund Investments	December 31, 2019 2018 Gross Other-Than- Gross Other-Than- Fair Unrealized Temporary Fair Unrealized Temporary Value Gains Impairments Value Gains Impairments (in millions) Cash and Cash Equivalents $ 15.3 $ — $ — $ 22.5 $ — $ — Fixed Income Securities: United States Government 1,112.5 55.5 (6.1 ) 996.1 26.7 (7.1 ) Corporate Debt 72.4 5.3 (1.6 ) 52.4 1.1 (1.9 ) State and Local Government 7.6 0.7 (0.2 ) 8.6 0.6 (0.2 ) Subtotal Fixed Income Securities 1,192.5 61.5 (7.9 ) 1,057.1 28.4 (9.2 ) Equity Securities - Domestic (a) 1,767.9 1,144.4 — 1,395.3 766.3 — Spent Nuclear Fuel and Decommissioning Trusts $ 2,975.7 $ 1,205.9 $ (7.9 ) $ 2,474.9 $ 794.7 $ (9.2 ) (a) Amount reported as Gross Unrealized Gains includes unrealized gains of $1.1 billion and $784 million and unrealized losses of $5 million and $18 million as of December 31, 2019 and 2018 , respectively. AEP adopted ASU 2016-01 during the first quarter of 2018 by means of a modified retrospective approach. Due to the adoption of the ASU, Other-Than-Temporary Impairments are no longer applicable to Equity Securities with readily determinable fair values.
Securities Activity Within the Decommissioning and SNF Trusts	Years Ended December 31, 2019 2018 2017 (in millions) Proceeds from Investment Sales $ 1,473.0 $ 2,010.0 $ 2,256.3 Purchases of Investments 1,531.0 2,064.7 2,300.5 Gross Realized Gains on Investment Sales 76.5 47.5 200.7 Gross Realized Losses on Investment Sales 24.3 32.8 146.0
Contractual Maturities, Fair Value of Debt Securities	Fair Value of Fixed Income Securities (in millions) Within 1 year $ 371.0 After 1 year through 5 years 386.2 After 5 years through 10 years 217.3 After 10 years 218.0 Total $ 1,192.5
Fair Value, Assets and Liabilities Measured on Recurring Basis	AEP Assets and Liabilities Measured at Fair Value on a Recurring Basis December 31, 2019 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Other Temporary Investments Restricted Cash and Other Cash Deposits (a) $ 197.6 $ — $ — $ 17.1 $ 214.7 Fixed Income Securities – Mutual Funds 123.3 — — — 123.3 Equity Securities – Mutual Funds (b) 50.5 — — — 50.5 Total Other Temporary Investments 371.4 — — 17.1 388.5 Risk Management Assets Risk Management Commodity Contracts (c) (d) 4.0 440.1 369.2 (404.5 ) 408.8 Cash Flow Hedges: Commodity Hedges (c) — 15.0 3.2 (6.7 ) 11.5 Interest Rate Hedges — 4.6 — — 4.6 Fair Value Hedges — 14.5 — — 14.5 Total Risk Management Assets 4.0 474.2 372.4 (411.2 ) 439.4 Spent Nuclear Fuel and Decommissioning Trusts Cash and Cash Equivalents (e) 6.7 — — 8.6 15.3 Fixed Income Securities: United States Government — 1,112.5 — — 1,112.5 Corporate Debt — 72.4 — — 72.4 State and Local Government — 7.6 — — 7.6 Subtotal Fixed Income Securities — 1,192.5 — — 1,192.5 Equity Securities – Domestic (b) 1,767.9 — — — 1,767.9 Total Spent Nuclear Fuel and Decommissioning Trusts 1,774.6 1,192.5 — 8.6 2,975.7 Total Assets $ 2,150.0 $ 1,666.7 $ 372.4 $ (385.5 ) $ 3,803.6 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (d) $ 3.8 $ 450.0 $ 224.0 $ (438.8 ) $ 239.0 Cash Flow Hedges: Commodity Hedges (c) — 105.3 38.5 (6.7 ) 137.1 Total Risk Management Liabilities $ 3.8 $ 555.3 $ 262.5 $ (445.5 ) $ 376.1 AEP Assets and Liabilities Measured at Fair Value on a Recurring Basis December 31, 2018 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Other Temporary Investments Restricted Cash and Other Cash Deposits (a) $ 221.5 $ — $ — $ 9.1 $ 230.6 Fixed Income Securities – Mutual Funds 104.3 — — — 104.3 Equity Securities – Mutual Funds (b) 34.2 — — — 34.2 Total Other Temporary Investments 360.0 — — 9.1 369.1 Risk Management Assets Risk Management Commodity Contracts (c) (f) 3.8 326.5 340.9 (288.5 ) 382.7 Cash Flow Hedges: Commodity Hedges (c) — 24.1 12.7 (2.7 ) 34.1 Total Risk Management Assets 3.8 350.6 353.6 (291.2 ) 416.8 Spent Nuclear Fuel and Decommissioning Trusts Cash and Cash Equivalents (e) 12.3 — — 10.2 22.5 Fixed Income Securities: United States Government — 996.1 — — 996.1 Corporate Debt — 52.4 — — 52.4 State and Local Government — 8.6 — — 8.6 Subtotal Fixed Income Securities — 1,057.1 — — 1,057.1 Equity Securities – Domestic (b) 1,395.3 — — — 1,395.3 Total Spent Nuclear Fuel and Decommissioning Trusts 1,407.6 1,057.1 — 10.2 2,474.9 Total Assets $ 1,771.4 $ 1,407.7 $ 353.6 $ (271.9 ) $ 3,260.8 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (f) $ 4.2 $ 327.0 $ 185.6 $ (274.7 ) $ 242.1 Cash Flow Hedges: Commodity Hedges (c) — 24.8 36.8 (2.7 ) 58.9 Fair Value Hedges — 17.4 — — 17.4 Total Risk Management Liabilities $ 4.2 $ 369.2 $ 222.4 $ (277.4 ) $ 318.4 AEP Texas Assets and Liabilities Measured at Fair Value on a Recurring Basis December 31, 2019 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 154.7 $ — $ — $ — $ 154.7 December 31, 2018 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 156.7 $ — $ — $ — $ 156.7 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) $ — $ 0.7 $ — $ (0.5 ) $ 0.2 APCo Assets and Liabilities Measured at Fair Value on a Recurring Basis December 31, 2019 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 23.5 $ — $ — $ — $ 23.5 Risk Management Assets Risk Management Commodity Contracts (c) (g) — 84.6 40.5 (85.6 ) 39.5 Total Assets $ 23.5 $ 84.6 $ 40.5 $ (85.6 ) $ 63.0 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 84.0 $ 2.8 $ (84.9 ) $ 1.9 December 31, 2018 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 25.6 $ — $ — $ — $ 25.6 Risk Management Assets Risk Management Commodity Contracts (c) (g) 0.1 59.1 58.3 (59.4 ) 58.1 Total Assets $ 25.7 $ 59.1 $ 58.3 $ (59.4 ) $ 83.7 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ 0.2 $ 58.4 $ 0.5 $ (58.5 ) $ 0.6 I&M Assets and Liabilities Measured at Fair Value on a Recurring Basis December 31, 2019 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ 59.5 $ 8.0 $ (57.6 ) $ 9.9 Spent Nuclear Fuel and Decommissioning Trusts Cash and Cash Equivalents (e) 6.7 — — 8.6 15.3 Fixed Income Securities: United States Government — 1,112.5 — — 1,112.5 Corporate Debt — 72.4 — — 72.4 State and Local Government — 7.6 — — 7.6 Subtotal Fixed Income Securities — 1,192.5 — — 1,192.5 Equity Securities - Domestic (b) 1,767.9 — — — 1,767.9 Total Spent Nuclear Fuel and Decommissioning Trusts 1,774.6 1,192.5 — 8.6 2,975.7 Total Assets $ 1,774.6 $ 1,252.0 $ 8.0 $ (49.0 ) $ 2,985.6 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 53.4 $ 2.2 $ (55.1 ) $ 0.5 December 31, 2018 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ 42.1 $ 10.3 $ (43.2 ) $ 9.2 Spent Nuclear Fuel and Decommissioning Trusts Cash and Cash Equivalents (e) 12.3 — — 10.2 22.5 Fixed Income Securities: United States Government — 996.1 — — 996.1 Corporate Debt — 52.4 — — 52.4 State and Local Government — 8.6 — — 8.6 Subtotal Fixed Income Securities — 1,057.1 — — 1,057.1 Equity Securities - Domestic (b) 1,395.3 — — — 1,395.3 Total Spent Nuclear Fuel and Decommissioning Trusts 1,407.6 1,057.1 — 10.2 2,474.9 Total Assets $ 1,407.6 $ 1,099.2 $ 10.3 $ (33.0 ) $ 2,484.1 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ 0.1 $ 41.2 $ 1.4 $ (42.3 ) $ 0.4 OPCo Assets and Liabilities Measured at Fair Value on a Recurring Basis December 31, 2019 Level 1 Level 2 Level 3 Other Total Liabilities: (in millions) Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ — $ 103.6 $ — $ 103.6 December 31, 2018 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 27.6 $ — $ — $ — $ 27.6 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 0.8 $ 99.4 $ (0.6 ) $ 99.6 PSO Assets and Liabilities Measured at Fair Value on a Recurring Basis December 31, 2019 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ — $ 16.3 $ (0.5 ) $ 15.8 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ — $ 0.5 $ (0.5 ) $ — December 31, 2018 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ — $ 10.8 $ (0.4 ) $ 10.4 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 0.3 $ 1.3 $ (0.6 ) $ 1.0 SWEPCo Assets and Liabilities Measured at Fair Value on a Recurring Basis December 31, 2019 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ — $ 6.5 $ (0.1 ) $ 6.4 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ — $ 5.1 $ (0.1 ) $ 5.0 December 31, 2018 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ — $ 5.6 $ (0.8 ) $ 4.8 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 0.4 $ 3.3 $ (1.1 ) $ 2.6 (a) Amounts in “Other” column primarily represent cash deposits in bank accounts with financial institutions or third-parties. Level 1 and Level 2 amounts primarily represent investments in money market funds. (b) Amounts represent publicly traded equity securities and equity-based mutual funds. (c) Amounts in “Other” column primarily represent counterparty netting of risk management and hedging contracts and associated cash collateral under the accounting guidance for “Derivatives and Hedging.” (d) The December 31, 2019 maturity of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), is as follows: Level 2 matures $(7) million in 2020 and $(3) million in periods 2021-2023; Level 3 matures $96 million in 2020, $36 million in periods 2021-2023, $25 million in periods 2024-2025 and $(12) million in periods 2026-2032. Risk management commodity contracts are substantially comprised of power contracts. (e) Amounts in “Other” column primarily represent accrued interest receivables from financial institutions. Level 1 amounts primarily represent investments in money market funds. (f) The December 31, 2018 maturity of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), is as follows: Level 2 matures $(4) million in 2019, $1 million in periods 2020-2022, $1 million in periods 2023-2024 and $1 million in periods 2025-2032; Level 3 matures $108 million in 2019, $37 million in periods 2020-2022, $23 million in periods 2023-2024 and $(12) million in periods 2025-2032. Risk management commodity contracts are substantially comprised of power contracts. (g) Substantially comprised of power contracts for the Registrant Subsidiaries.
Changes in Fair Value of Net Trading Derivatives Classified as Level 3	Year Ended December 31, 2019 AEP APCo I&M OPCo PSO SWEPCo (in millions) Balance as of December 31, 2018 $ 131.2 $ 57.8 $ 8.9 $ (99.4 ) $ 9.5 $ 2.3 Realized Gain (Loss) Included in Net Income (or Changes in Net Assets) (a) (b) 15.8 (13.9 ) 4.7 (0.9 ) 13.5 6.0 Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date (a) (0.1 ) — — — — — Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income (c) (15.1 ) — — — — — Settlements (117.6 ) (42.5 ) (13.0 ) 6.6 (23.0 ) (9.6 ) Transfers into Level 3 (d) (e) (0.6 ) (0.5 ) (0.3 ) — — — Transfers out of Level 3 (e) 35.6 (0.7 ) (0.4 ) — — — Changes in Fair Value Allocated to Regulated Jurisdictions (f) 60.7 37.5 5.9 (9.9 ) 15.8 2.7 Balance as of December 31, 2019 $ 109.9 $ 37.7 $ 5.8 $ (103.6 ) $ 15.8 $ 1.4 Year Ended December 31, 2018 AEP APCo I&M OPCo PSO SWEPCo (in millions) Balance as of December 31, 2017 $ 40.3 $ 24.7 $ 7.6 $ (132.4 ) $ 6.2 $ 5.9 Realized Gain (Loss) Included in Net Income (or Changes in Net Assets) (a) (b) 148.9 104.1 14.2 1.8 18.1 (4.8 ) Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date (a) 9.8 — — — — — Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income (c) 15.7 — — — — — Settlements (214.0 ) (127.9 ) (21.3 ) 4.6 (24.3 ) (2.1 ) Transfers into Level 3 (d) (e) 15.8 — — — — — Transfers out of Level 3 (e) (1.6 ) — (0.3 ) — — — Changes in Fair Value Allocated to Regulated Jurisdictions (f) 116.3 56.9 8.7 26.6 9.5 3.3 Balance as of December 31, 2018 $ 131.2 $ 57.8 $ 8.9 $ (99.4 ) $ 9.5 $ 2.3 Year Ended December 31, 2017 AEP APCo I&M OPCo PSO SWEPCo (in millions) Balance as of December 31, 2016 $ 2.5 $ 1.4 $ 2.8 $ (119.0 ) $ 0.7 $ 0.7 Realized Gain (Loss) Included in Net Income (or Changes in Net Assets) (a) (b) 37.3 17.2 4.0 (1.4 ) 3.1 6.0 Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date (a) 33.6 — — — — — Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income (c) (18.8 ) — — — — — Settlements (50.6 ) (18.9 ) (7.1 ) 7.4 (3.8 ) (6.8 ) Transfers into Level 3 (d) (e) 16.2 — — — — — Transfers out of Level 3 (e) (10.1 ) — — — — — Changes in Fair Value Allocated to Regulated Jurisdictions (f) 30.2 25.0 7.9 (19.4 ) 6.2 6.0 Balance as of December 31, 2017 $ 40.3 $ 24.7 $ 7.6 $ (132.4 ) $ 6.2 $ 5.9 (a) Included in revenues on the statements of income. (b) Represents the change in fair value between the beginning of the reporting period and the settlement of the risk management commodity contract. (c) Included in cash flow hedges on the statements of comprehensive income. (d) Represents existing assets or liabilities that were previously categorized as Level 2. (e) Transfers are recognized based on their value at the beginning of the reporting period that the transfer occurred. (f) Relates to the net gains (losses) of those contracts that are not reflected on the statements of income. These net gains (losses) are recorded as regulatory assets/liabilities or accounts payable.
Significant Unobservable Inputs for Level 3	Significant Unobservable Inputs December 31, 2019 AEP Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input Low High Average (c) (in millions) Energy Contracts $ 296.7 $ 249.3 Discounted Cash Flow Forward Market Price (a) $ (0.05 ) $ 177.30 $ 31.31 Natural Gas Contracts — 4.9 Discounted Cash Flow Forward Market Price (b) 1.89 2.51 2.19 FTRs 75.7 8.3 Discounted Cash Flow Forward Market Price (a) (8.52 ) 9.34 0.42 Total $ 372.4 $ 262.5 December 31, 2018 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input Low High Average (c) (in millions) Energy Contracts $ 257.1 $ 212.5 Discounted Cash Flow Forward Market Price (a) $ (0.05 ) $ 176.57 $ 33.07 Natural Gas Contracts — 2.5 Discounted Cash Flow Forward Market Price (b) 2.18 3.54 2.47 FTRs 96.5 7.4 Discounted Cash Flow Forward Market Price (a) (11.68 ) 17.79 1.09 Total $ 353.6 $ 222.4 APCo Significant Unobservable Inputs December 31, 2019 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ 5.7 $ 2.6 Discounted Cash Flow Forward Market Price $ 12.70 $ 41.20 $ 25.92 FTRs 34.8 0.2 Discounted Cash Flow Forward Market Price (0.14 ) 7.08 1.70 Total $ 40.5 $ 2.8 December 31, 2018 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ 2.4 $ 0.5 Discounted Cash Flow Forward Market Price $ 16.82 $ 62.65 $ 37.00 FTRs 55.9 — Discounted Cash Flow Forward Market Price 0.10 15.16 3.27 Total $ 58.3 $ 0.5 I&M Significant Unobservable Inputs December 31, 2019 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ 3.4 $ 1.5 Discounted Cash Flow Forward Market Price $ 12.70 $ 41.20 $ 25.92 FTRs 4.6 0.7 Discounted Cash Flow Forward Market Price (0.75 ) 4.07 0.74 Total $ 8.0 $ 2.2 December 31, 2018 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ 1.4 $ 0.9 Discounted Cash Flow Forward Market Price $ 16.82 $ 62.65 $ 37.00 FTRs 8.9 0.5 Discounted Cash Flow Forward Market Price (2.11 ) 6.21 1.06 Total $ 10.3 $ 1.4 OPCo Significant Unobservable Inputs December 31, 2019 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ — $ 103.6 Discounted Cash Flow Forward Market Price $ 29.23 $ 61.43 $ 42.46 December 31, 2018 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ — $ 99.4 Discounted Cash Flow Forward Market Price $ 26.29 $ 62.74 $ 42.50 PSO Significant Unobservable Inputs December 31, 2019 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) FTRs $ 16.3 $ 0.5 Discounted Cash Flow Forward Market Price $ (8.52 ) $ 0.85 $ (2.31 ) December 31, 2018 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) FTRs $ 10.8 $ 1.3 Discounted Cash Flow Forward Market Price $ (11.68 ) $ 10.30 $ (1.40 ) SWEPCo Significant Unobservable Inputs December 31, 2019 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input Low High Average (c) (in millions) Natural Gas Contracts $ — $ 4.9 Discounted Cash Flow Forward Market Price (b) $ 1.89 $ 2.51 $ 2.18 FTRs 6.5 0.2 Discounted Cash Flow Forward Market Price (a) (8.52 ) 0.85 (2.31 ) Total $ 6.5 $ 5.1 December 31, 2018 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input Low High Average (c) (in millions) Natural Gas Contracts $ — $ 2.5 Discounted Cash Flow Forward Market Price (b) $ 2.18 $ 3.54 $ 2.47 FTRs 5.6 0.8 Discounted Cash Flow Forward Market Price (a) (11.68 ) 10.30 (1.40 ) Total $ 5.6 $ 3.3 (a) Represents market prices in dollars per MWh. (b) Represents market prices in dollars per MMBtu. (c) The weighted average is the product of the forward market price of the underlying commodity and volume weighted by term.
Sensitivity of Fair Value Measurements	Uncertainty of Fair Value Measurements Significant Unobservable Input Position Change in Input Impact on Fair Value Measurement Forward Market Price Buy Increase (Decrease) Higher (Lower) Forward Market Price Sell Increase (Decrease) Lower (Higher)

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Details of Income Taxes as Reported	Year Ended December 31, 2019 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Federal: Current $ (7.4 ) $ (31.8 ) $ 23.7 $ 36.7 $ 48.1 $ (10.0 ) $ 25.5 $ 6.9 Deferred (77.1 ) (23.5 ) 71.7 (125.6 ) (53.5 ) 40.6 (23.6 ) (8.6 ) Deferred Investment Tax Credits 5.5 (1.2 ) — (0.5 ) (3.6 ) — (2.4 ) (1.4 ) Total Federal (79.0 ) (56.5 ) 95.4 (89.4 ) (9.0 ) 30.6 (0.5 ) (3.1 ) State and Local: Current 4.4 2.9 2.4 12.0 (2.4 ) 1.1 0.2 0.8 Deferred 59.3 — 19.6 (0.6 ) 0.8 3.2 5.4 (2.4 ) Deferred Investment Tax Credits 2.4 — — — — — 2.4 — Total State and Local 66.1 2.9 22.0 11.4 (1.6 ) 4.3 8.0 (1.6 ) Income Tax Expense (Benefit) $ (12.9 ) $ (53.6 ) $ 117.4 $ (78.0 ) $ (10.6 ) $ 34.9 $ 7.5 $ (4.7 ) Year Ended December 31, 2018 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Federal: Current $ (31.7 ) $ 37.0 $ (14.2 ) $ (31.9 ) $ 60.9 $ 55.6 $ 35.6 $ 18.3 Deferred 112.8 (16.4 ) 82.3 (24.6 ) (44.1 ) (36.9 ) (34.7 ) (0.5 ) Deferred Investment Tax Credits 9.2 (1.5 ) — 0.1 (4.7 ) — (2.0 ) (1.4 ) Total Federal 90.3 19.1 68.1 (56.4 ) 12.1 18.7 (1.1 ) 16.4 State and Local: Current 30.8 1.8 (0.6 ) 3.7 15.8 4.6 (0.2 ) 2.3 Deferred (8.5 ) (0.1 ) 16.6 7.8 1.2 0.7 3.6 1.7 Deferred Investment Tax Credits 2.7 — — — — — 2.7 — Total State and Local 25.0 1.7 16.0 11.5 17.0 5.3 6.1 4.0 Income Tax Expense (Benefit) $ 115.3 $ 20.8 $ 84.1 $ (44.9 ) $ 29.1 $ 24.0 $ 5.0 $ 20.4 Year Ended December 31, 2017 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Federal: Current $ (4.0 ) $ (85.7 ) $ (130.4 ) $ 15.3 $ (106.5 ) $ 11.2 $ (77.1 ) $ (30.1 ) Deferred 856.6 63.3 254.8 166.9 202.1 141.3 122.7 84.8 Deferred Investment Tax Credits 48.6 (1.6 ) — (0.1 ) (4.7 ) — (1.6 ) (1.4 ) Total Federal 901.2 (24.0 ) 124.4 182.1 90.9 152.5 44.0 53.3 State and Local: Current 16.0 0.6 1.1 (1.4 ) (8.1 ) 0.2 (0.2 ) (0.9 ) Deferred 44.9 — 16.7 4.6 (1.4 ) 6.6 2.0 (4.3 ) Deferred Investment Tax Credits 7.6 — — — — — 4.3 — Total State and Local 68.5 0.6 17.8 3.2 (9.5 ) 6.8 6.1 (5.2 ) Income Tax Expense (Benefit) $ 969.7 $ (23.4 ) $ 142.2 $ 185.3 $ 81.4 $ 159.3 $ 50.1 $ 48.1
Reconciliation of Federal Statutory Tax Rate to Reported Tax Rate	AEP Years Ended December 31, 2019 2018 2017 (in millions) Net Income $ 1,919.8 $ 1,931.3 $ 1,928.9 Less: Equity Earnings – Dolet Hills (3.0 ) (2.7 ) — Income Tax Expense (Benefit) (12.9 ) 115.3 969.7 Pretax Income $ 1,903.9 $ 2,043.9 $ 2,898.6 Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively) $ 399.8 $ 429.2 $ 1,014.5 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 23.1 24.4 60.2 Investment Tax Credit Amortization (13.0 ) (20.2 ) (18.8 ) Production Tax Credits (59.0 ) (10.3 ) — State and Local Income Taxes, Net 52.2 19.7 54.7 Removal Costs (20.7 ) (19.8 ) (32.7 ) AFUDC (37.1 ) (29.4 ) (37.4 ) Valuation Allowance — — (1.8 ) Tax Reform Adjustments — (10.9 ) (26.7 ) Tax Adjustments — — (35.8 ) Tax Reform Excess ADIT Reversal (353.2 ) (257.2 ) — Other (5.0 ) (10.2 ) (6.5 ) Income Tax Expense (Benefit) $ (12.9 ) $ 115.3 $ 969.7 Effective Income Tax Rate (0.7 ) % 5.6 % 33.5 % AEP Texas Years Ended December 31, 2019 2018 2017 (in millions) Net Income $ 178.3 $ 211.3 $ 310.5 Income Tax Expense (Benefit) (53.6 ) 20.8 (23.4 ) Pretax Income $ 124.7 $ 232.1 $ 287.1 Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively) $ 26.2 $ 48.7 $ 100.5 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 1.0 1.4 (0.5 ) Investment Tax Credit Amortization (1.2 ) (2.3 ) (1.5 ) State and Local Income Taxes, Net 2.3 1.3 0.4 AFUDC (3.2 ) (4.2 ) (3.9 ) Parent Company Loss Benefit (4.6 ) (3.1 ) — Tax Reform Adjustments — (11.0 ) (117.4 ) Tax Adjustments — — (4.2 ) Tax Reform Excess ADIT Reversal (73.4 ) (11.8 ) — Other (0.7 ) 1.8 3.2 Income Tax Expense (Benefit) $ (53.6 ) $ 20.8 $ (23.4 ) Effective Income Tax Rate (43.0 ) % 9.0 % (8.2 ) % AEPTCo Years Ended December 31, 2019 2018 2017 (in millions) Net Income $ 439.7 $ 315.9 $ 270.7 Income Tax Expense 117.4 84.1 142.2 Pretax Income $ 557.1 $ 400.0 $ 412.9 Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively) $ 117.0 $ 84.0 $ 144.5 Increase (Decrease) in Income Taxes Resulting from the Following Items: AFUDC (17.7 ) (14.1 ) (17.0 ) State and Local Income Taxes, Net 17.4 12.6 13.1 Tax Reform Adjustments — — 0.6 Other 0.7 1.6 1.0 Income Tax Expense $ 117.4 $ 84.1 $ 142.2 Effective Income Tax Rate 21.1 % 21.0 % 34.4 % APCo Years Ended December 31, 2019 2018 2017 (in millions) Net Income $ 306.3 $ 367.8 $ 331.3 Income Tax Expense (Benefit) (78.0 ) (44.9 ) 185.3 Pretax Income $ 228.3 $ 322.9 $ 516.6 Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively) $ 47.9 $ 67.8 $ 180.8 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 11.7 8.5 18.0 State and Local Income Taxes, Net 9.0 9.1 3.5 Removal Costs (6.1 ) (9.6 ) (12.4 ) AFUDC (5.2 ) (4.3 ) (5.0 ) Parent Company Loss Benefit (3.8 ) (3.4 ) (0.2 ) Tax Reform Adjustments — 0.1 4.3 Tax Reform Excess ADIT Reversal (130.4 ) (108.5 ) — Other (1.1 ) (4.6 ) (3.7 ) Income Tax Expense (Benefit) $ (78.0 ) $ (44.9 ) $ 185.3 Effective Income Tax Rate (34.2 ) % (13.9 ) % 35.9 % I&M Years Ended December 31, 2019 2018 2017 (in millions) Net Income $ 269.4 $ 261.3 $ 186.7 Income Tax Expense (Benefit) (10.6 ) 29.1 81.4 Pretax Income $ 258.8 $ 290.4 $ 268.1 Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively) $ 54.3 $ 61.0 $ 93.8 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 6.3 (0.7 ) 11.4 Investment Tax Credit Amortization (3.6 ) (4.7 ) (4.7 ) State and Local Income Taxes, Net (1.2 ) 13.4 (1.0 ) Removal Costs (11.5 ) (8.0 ) (13.3 ) AFUDC (4.1 ) (2.5 ) (5.6 ) Parent Company Loss Benefit (4.8 ) (2.3 ) — Tax Adjustments — — 2.7 Tax Reform Adjustments — — (2.9 ) Tax Reform Excess ADIT Reversal (42.5 ) (25.8 ) — Other (3.5 ) (1.3 ) 1.0 Income Tax Expense (Benefit) $ (10.6 ) $ 29.1 $ 81.4 Effective Income Tax Rate (4.1 ) % 10.0 % 30.4 % OPCo Years Ended December 31, 2019 2018 2017 (in millions) Net Income $ 297.1 $ 325.5 $ 323.9 Income Tax Expense 34.9 24.0 159.3 Pretax Income $ 332.0 $ 349.5 $ 483.2 Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively) $ 69.7 $ 73.4 $ 169.1 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation (1.7 ) 2.6 7.6 State and Local Income Taxes, Net 3.4 4.2 4.4 AFUDC (3.8 ) (2.1 ) (2.2 ) Tax Reform Adjustments — — (14.4 ) Tax Reform Excess ADIT Reversal (27.3 ) (51.0 ) — Parent Company Loss Benefit (4.9 ) (5.5 ) (0.2 ) Other (0.5 ) 2.4 (5.0 ) Income Tax Expense $ 34.9 $ 24.0 $ 159.3 Effective Income Tax Rate 10.5 % 6.9 % 33.0 % PSO Years Ended December 31, 2019 2018 2017 (in millions) Net Income $ 137.6 $ 83.2 $ 72.0 Income Tax Expense 7.5 5.0 50.1 Pretax Income $ 145.1 $ 88.2 $ 122.1 Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively) $ 30.5 $ 18.5 $ 42.7 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 0.5 1.0 0.3 Investment Tax Credit Amortization (0.5 ) (1.7 ) (1.6 ) Parent Company Loss Benefit (2.5 ) (1.4 ) — State and Local Income Taxes, Net 6.3 4.8 4.0 Tax Reform Adjustments — — 2.8 Tax Reform Excess ADIT Reversal (24.5 ) (15.5 ) — Other (2.3 ) (0.7 ) 1.9 Income Tax Expense $ 7.5 $ 5.0 $ 50.1 Effective Income Tax Rate 5.2 % 5.7 % 41.0 % SWEPCo Years Ended December 31, 2019 2018 2017 (in millions) Net Income $ 162.2 $ 152.2 $ 137.5 Less: Equity Earnings – Dolet Hills (3.0 ) (2.7 ) — Income Tax Expense (Benefit) (4.7 ) 20.4 48.1 Pretax Income $ 154.5 $ 169.9 $ 185.6 Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively) $ 32.4 $ 35.7 $ 65.0 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 1.9 3.4 1.9 Depletion (3.6 ) (3.2 ) (5.7 ) State and Local Income Taxes, Net (1.3 ) 3.2 (2.3 ) AFUDC (1.4 ) (1.3 ) (0.9 ) Tax Adjustments — — (9.9 ) Tax Reform Adjustments — — (0.4 ) Tax Reform Excess ADIT Reversal (29.9 ) (16.0 ) — Other (2.8 ) (1.4 ) 0.4 Income Tax Expense (Benefit) $ (4.7 ) $ 20.4 $ 48.1 Effective Income Tax Rate (3.0 ) % 12.0 % 25.9 %
Reconciliation of Significant Temporary Differences	AEP December 31, 2019 2018 (in millions) Deferred Tax Assets $ 3,246.1 $ 2,750.8 Deferred Tax Liabilities (10,834.3 ) (9,837.3 ) Net Deferred Tax Liabilities $ (7,588.2 ) $ (7,086.5 ) Property Related Temporary Differences $ (6,602.9 ) $ (6,224.8 ) Amounts Due to Customers for Future Income Taxes 1,173.5 1,329.7 Deferred State Income Taxes (1,112.4 ) (1,072.5 ) Securitized Assets (178.7 ) (186.6 ) Regulatory Assets (371.1 ) (454.1 ) Accrued Nuclear Decommissioning (557.4 ) (453.7 ) Net Operating Loss Carryforward 77.6 78.3 Tax Credit Carryforward 247.2 113.7 Operating Lease Liability 182.6 — Investment in Partnership (446.6 ) (300.5 ) All Other, Net — 84.0 Net Deferred Tax Liabilities $ (7,588.2 ) $ (7,086.5 ) AEP Texas December 31, 2019 2018 (in millions) Deferred Tax Assets $ 220.0 $ 208.1 Deferred Tax Liabilities (1,185.4 ) (1,121.2 ) Net Deferred Tax Liabilities $ (965.4 ) $ (913.1 ) Property Related Temporary Differences $ (973.5 ) $ (836.3 ) Amounts Due to Customers for Future Income Taxes 126.7 141.2 Deferred State Income Taxes (27.5 ) (27.7 ) Regulatory Assets (51.2 ) (53.9 ) Securitized Transition Assets (124.3 ) (134.7 ) Deferred Revenues 19.9 4.6 Operating Lease Liability 17.2 — All Other, Net 47.3 (6.3 ) Net Deferred Tax Liabilities $ (965.4 ) $ (913.1 ) AEPTCo December 31, 2019 2018 (in millions) Deferred Tax Assets $ 162.9 $ 142.9 Deferred Tax Liabilities (980.7 ) (847.3 ) Net Deferred Tax Liabilities $ (817.8 ) $ (704.4 ) Property Related Temporary Differences $ (847.1 ) $ (755.0 ) Amounts Due to Customers for Future Income Taxes 119.9 121.3 Deferred State Income Taxes (86.1 ) (71.6 ) Net Operating Loss Carryforward 12.3 13.4 All Other, Net (16.8 ) (12.5 ) Net Deferred Tax Liabilities $ (817.8 ) $ (704.4 ) APCo December 31, 2019 2018 (in millions) Deferred Tax Assets $ 486.2 $ 475.2 Deferred Tax Liabilities (2,167.0 ) (2,101.0 ) Net Deferred Tax Liabilities $ (1,680.8 ) $ (1,625.8 ) Property Related Temporary Differences $ (1,420.0 ) $ (1,393.6 ) Amounts Due to Customers for Future Income Taxes 222.8 268.0 Deferred State Income Taxes (320.9 ) (324.1 ) Regulatory Assets (71.0 ) (73.8 ) Securitized Assets (49.3 ) (54.3 ) Operating Lease Liability 16.5 — All Other, Net (58.9 ) (48.0 ) Net Deferred Tax Liabilities $ (1,680.8 ) $ (1,625.8 ) I&M December 31, 2019 2018 (in millions) Deferred Tax Assets $ 970.5 $ 771.6 Deferred Tax Liabilities (1,950.2 ) (1,719.6 ) Net Deferred Tax Liabilities $ (979.7 ) $ (948.0 ) Property Related Temporary Differences $ (430.7 ) $ (445.0 ) Amounts Due to Customers for Future Income Taxes 169.6 186.2 Deferred State Income Taxes (194.4 ) (183.9 ) Accrued Nuclear Decommissioning (557.4 ) (453.7 ) Regulatory Assets (26.9 ) (31.9 ) Net Operating Loss Carryforward — 0.2 Operating Lease Liability 61.9 — All Other, Net (1.8 ) (19.9 ) Net Deferred Tax Liabilities $ (979.7 ) $ (948.0 ) OPCo December 31, 2019 2018 (in millions) Deferred Tax Assets $ 202.3 $ 209.0 Deferred Tax Liabilities (1,051.6 ) (972.3 ) Net Deferred Tax Liabilities $ (849.3 ) $ (763.3 ) Property Related Temporary Differences $ (890.8 ) $ (826.9 ) Amounts Due to Customers for Future Income Taxes 130.2 137.0 Deferred State Income Taxes (35.5 ) (32.9 ) Regulatory Assets (48.0 ) (55.0 ) Operating Lease Liability 18.3 — All Other, Net (23.5 ) 14.5 Net Deferred Tax Liabilities $ (849.3 ) $ (763.3 ) PSO December 31, 2019 2018 (in millions) Deferred Tax Assets $ 257.4 $ 229.6 Deferred Tax Liabilities (885.7 ) (837.4 ) Net Deferred Tax Liabilities $ (628.3 ) $ (607.8 ) Property Related Temporary Differences $ (627.6 ) $ (609.4 ) Amounts Due to Customers for Future Income Taxes 127.2 138.9 Deferred State Income Taxes (100.4 ) (135.6 ) Regulatory Assets (44.6 ) (32.3 ) Net Operating Loss Carryforward 10.2 16.4 All Other, Net 6.9 14.2 Net Deferred Tax Liabilities $ (628.3 ) $ (607.8 ) SWEPCo December 31, 2019 2018 (in millions) Deferred Tax Assets $ 359.6 $ 317.4 Deferred Tax Liabilities (1,300.5 ) (1,220.2 ) Net Deferred Tax Liabilities $ (940.9 ) $ (902.8 ) Property Related Temporary Differences $ (947.6 ) $ (913.3 ) Amounts Due to Customers for Future Income Taxes 169.8 183.4 Deferred State Income Taxes (200.3 ) (193.6 ) Regulatory Assets (30.2 ) (30.8 ) Net Operating Loss Carryforward 38.2 36.2 All Other, Net 29.2 15.3 Net Deferred Tax Liabilities $ (940.9 ) $ (902.8 )
State Net Income Tax Operating Loss Carryforwards	State Net Income Tax Operating Loss Years of Company State/Municipality Carryforward Expiration (in millions) AEP Arkansas $ 102.5 2020 - 2024 AEP Kentucky 144.9 2030 - 2037 AEP Louisiana 541.0 2025 - 2039 AEP Oklahoma 544.1 2034 - 2037 AEP Tennessee 29.0 2028 - 2034 AEP Virginia 22.6 2030 - 2037 AEP West Virginia 16.1 2029 - 2037 AEP Ohio Municipal 414.1 2020 - 2024 AEPTCo Oklahoma 269.4 2034 - 2037 AEPTCo Ohio Municipal 37.3 2020 - 2023 I&M West Virginia 2.0 2031 - 2037 PSO Oklahoma 240.5 2034 - 2037 SWEPCo Arkansas 101.7 2021 - 2024 SWEPCo Louisiana 528.1 2032 - 2037
Summary of Tax Credit Carryforwards	Federal Tax State Tax Credit Credit Total Federal Carryforward Total State Carryforward Tax Credit Subject to Tax Credit Subject to Company Carryforward Expiration Carryforward Expiration (in millions) AEP $ 247.2 $ 239.6 $ 36.7 $ — AEP Texas 1.4 1.3 — — AEPTCo 0.2 0.1 — — APCo 4.9 2.3 — — I&M 13.9 13.7 — — OPCo 5.1 1.7 — — PSO 1.1 1.1 36.7 — SWEPCo 1.9 1.8 — —
Reconciliation of Beginning and Ending Unrecognized Tax Benefits	AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Balance as of January 1, 2019 $ 14.6 $ (0.8 ) $ — $ — $ 3.2 $ 6.9 $ — $ (0.8 ) Increase – Tax Positions Taken During a Prior Period 8.8 1.5 — — — 1.6 — 0.8 Decrease – Tax Positions Taken During a Prior Period (2.1 ) (0.7 ) — — (0.7 ) — — — Increase – Tax Positions Taken During the Current Year 2.8 — — — — — — — Decrease – Tax Positions Taken During the Current Year — — — — — — — — Decrease – Settlements with Taxing Authorities — — — — — — — — Decrease – Lapse of the Applicable Statute of Limitations — — — — — — — — Balance as of December 31, 2019 $ 24.1 $ — $ — $ — $ 2.5 $ 8.5 $ — $ — AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Balance as of January 1, 2018 $ 86.6 $ (0.8 ) $ — $ — $ 3.2 $ 6.9 $ — $ (0.8 ) Increase – Tax Positions Taken During a Prior Period 0.1 — — — — — — — Decrease – Tax Positions Taken During a Prior Period — — — — — — — — Increase – Tax Positions Taken During the Current Year — — — — — — — — Decrease – Tax Positions Taken During the Current Year — — — — — — — — Decrease – Settlements with Taxing Authorities (71.0 ) — — — — — — — Decrease – Lapse of the Applicable Statute of Limitations (1.1 ) — — — — — — — Balance as of December 31, 2018 $ 14.6 $ (0.8 ) $ — $ — $ 3.2 $ 6.9 $ — $ (0.8 ) AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Balance as of January 1, 2017 $ 98.8 $ 6.5 $ — $ — $ 3.8 $ 6.9 $ 0.1 $ 1.3 Increase – Tax Positions Taken During a Prior Period 4.5 2.0 — — 0.2 — 0.1 1.7 Decrease – Tax Positions Taken During a Prior Period (28.0 ) (12.3 ) — — (0.5 ) — (0.9 ) (5.4 ) Increase – Tax Positions Taken During the Current Year 3.4 — — — — — — — Decrease – Tax Positions Taken During the Current Year — — — — — — — — Decrease – Settlements with Taxing Authorities 7.9 3.0 — — (0.3 ) — 0.7 1.6 Decrease – Lapse of the Applicable Statute of Limitations — — — — — — — — Balance as of December 31, 2017 $ 86.6 $ (0.8 ) $ — $ — $ 3.2 $ 6.9 $ — $ (0.8 )
Unrecognized Tax Benefits Affecting Effective Tax Rate	Company 2019 2018 2017 (in millions) AEP $ 20.3 $ 11.6 $ 10.5 AEP Texas — (0.7 ) (0.5 ) AEPTCo — — — APCo — — — I&M 2.0 2.6 2.1 OPCo 6.7 5.4 4.5 PSO — — — SWEPCo — (0.6 ) (0.5 )

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Lease Rental Costs	Year Ended December 31, 2019 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Operating Lease Cost $ 286.0 $ 16.5 $ 2.5 $ 19.5 $ 93.1 $ 18.0 $ 6.8 $ 8.0 Finance Lease Cost: Amortization of Right-of-Use Assets 70.8 5.1 0.1 6.7 5.7 3.5 3.1 11.0 Interest on Lease Liabilities 16.4 1.4 — 2.9 2.9 0.7 0.6 2.9 Total Lease Rental Costs (a) $ 373.2 $ 23.0 $ 2.6 $ 29.1 $ 101.7 $ 22.2 $ 10.5 $ 21.9 Year Ended December 31, 2018 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Operating Lease Cost $ 245.0 $ 13.6 $ 2.7 $ 18.2 $ 89.2 $ 10.7 $ 5.7 $ 6.5 Finance Lease Cost: Amortization of Right-of-Use Assets 62.4 4.8 0.1 7.0 6.6 3.9 3.2 11.2 Interest on Lease Liabilities 16.4 1.2 — 3.0 3.3 0.5 0.4 3.2 Total Lease Rental Costs $ 323.8 $ 19.6 $ 2.8 $ 28.2 $ 99.1 $ 15.1 $ 9.3 $ 20.9 Year Ended December 31, 2017 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Operating Lease Cost $ 231.3 $ 10.5 $ 1.7 $ 17.5 $ 88.4 $ 8.2 $ 4.4 $ 5.3 Finance Lease Cost: Amortization of Right-of-Use Assets 66.3 4.0 — 6.9 11.1 4.1 4.0 11.2 Interest on Lease Liabilities 16.7 0.8 — 3.7 3.2 0.5 0.6 3.6 Total Lease Rental Costs $ 314.3 $ 15.3 $ 1.7 $ 28.1 $ 102.7 $ 12.8 $ 9.0 $ 20.1 (a) Excludes variable and short-term lease costs, which were immaterial for the twelve months ended December 31, 2019 .
Supplemental Balance Sheet Information Related to Leases	December 31, 2019 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo Weighted-Average Remaining Lease Term (years): Operating Leases 5.23 6.93 2.25 6.28 3.91 7.94 7.07 6.64 Finance Leases 5.85 6.69 0.25 6.12 6.55 6.49 6.23 5.16 Weighted-Average Discount Rate: Operating Leases 3.60 % 3.77 % 3.14 % 3.64 % 3.45 % 3.76 % 3.64 % 3.76 % Finance Leases 5.98 % 4.62 % 9.33 % 8.08 % 8.47 % 4.54 % 4.62 % 5.01 % Year Ended December 31,2019 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Cash paid for amounts included in the measurement of lease liabilities: Operating Cash Flows Used for Operating Leases $ 284.7 $ 15.3 $ 2.4 $ 19.0 $ 94.3 $ 18.0 $ 6.7 $ 7.9 Operating Cash Flows Used for Finance Leases 16.4 1.4 — 2.9 3.1 0.7 0.6 3.0 Financing Cash Flows Used for Finance Leases 70.7 5.1 — 6.7 5.7 3.5 3.1 11.0 Non-cash Acquisitions Under Operating Leases $ 125.0 $ 13.8 $ 0.6 $ 10.2 $ 18.7 $ 35.4 $ 8.2 $ 11.4
Property, Plant and Equipment and Related Obligations Under Finance Leases	December 31, 2019 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Property, Plant and Equipment Under Finance Leases: Generation $ 131.6 $ — $ — $ 39.9 $ 28.8 $ — $ 0.6 $ 34.1 Other Property, Plant and Equipment 323.0 45.9 0.2 18.9 39.3 27.3 21.6 51.6 Total Property, Plant and Equipment 454.6 45.9 0.2 58.8 68.1 27.3 22.2 85.7 Accumulated Amortization 151.5 11.8 0.2 17.0 23.0 7.2 7.1 28.4 Net Property, Plant and Equipment Under Finance Leases $ 303.1 $ 34.1 $ — $ 41.8 $ 45.1 $ 20.1 $ 15.1 $ 57.3 Obligations Under Finance Leases: Noncurrent Liability $ 249.2 $ 28.2 $ — $ 35.0 $ 38.8 $ 16.2 $ 11.9 $ 47.1 Liability Due Within One Year 57.6 5.9 — 6.8 6.3 3.9 3.2 10.5 Total Obligations Under Finance Leases $ 306.8 $ 34.1 $ — $ 41.8 $ 45.1 $ 20.1 $ 15.1 $ 57.6	December 31, 2018 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Property, Plant and Equipment Under Finance Leases: Generation $ 131.3 $ — $ — $ 38.7 $ 27.0 $ — $ 2.6 $ 34.3 Other Property, Plant and Equipment 373.9 38.8 0.2 17.3 33.3 20.4 17.6 119.8 Total Property, Plant and Equipment 505.2 38.8 0.2 56.0 60.3 20.4 20.2 154.1 Accumulated Amortization 226.4 10.3 0.1 16.2 21.6 8.3 7.9 99.9 Net Property, Plant and Equipment Under Finance Leases $ 278.8 $ 28.5 $ 0.1 $ 39.8 $ 38.7 $ 12.1 $ 12.3 $ 54.2 Obligations Under Finance Leases: Noncurrent Liability $ 233.5 $ 24.0 $ — $ 33.7 $ 33.4 $ 9.2 $ 9.5 $ 50.6 Liability Due Within One Year 55.5 55.5 4.5 0.1 6.1 5.3 2.9 2.8 10.2 Total Obligations Under Finance Leases $ 289.0 $ 28.5 $ 0.1 $ 39.8 $ 38.7 $ 12.1 $ 12.3 $ 60.8
Operating Lease Assets and Related Obligations	December 31, 2019 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Operating Lease Assets $ 957.4 $ 81.8 $ 3.8 $ 78.5 $ 294.9 $ 88.0 $ 36.8 $ 40.5 Obligations Under Operating Leases: Noncurrent Liability $ 734.6 $ 71.1 $ 1.9 $ 64.0 $ 211.6 $ 76.0 $ 31.0 $ 34.7 Liability Due Within One Year 234.1 12.0 2.1 15.2 87.3 12.5 5.8 6.5 Total Obligations Under Operating Leases $ 968.7 $ 83.1 $ 4.0 $ 79.2 $ 298.9 $ 88.5 $ 36.8 $ 41.2
Finance Lease Liabilities Rolling Future Minimum Lease Payments	Finance Leases AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) 2020 $ 72.7 $ 7.3 $ — $ 9.6 $ 9.4 $ 4.7 $ 3.8 $ 12.9 2021 64.9 6.7 — 8.9 8.7 4.3 3.2 11.9 2022 56.4 6.0 — 8.2 8.0 3.4 2.6 10.6 2023 49.6 5.4 — 7.7 7.5 2.8 2.3 9.8 2024 57.4 4.6 — 7.1 10.8 2.4 1.8 14.2 Later Years 64.4 9.8 — 9.8 16.4 5.7 3.8 6.8 Total Future Minimum Lease Payments 365.4 39.8 — 51.3 60.8 23.3 17.5 66.2 Less: Imputed Interest 58.6 5.7 — 9.5 15.7 3.2 2.4 8.6 Estimated Present Value of Future Minimum Lease Payments $ 306.8 $ 34.1 $ — $ 41.8 $ 45.1 $ 20.1 $ 15.1 $ 57.6
Operating Lease Liabilities Rolling Future Minimum Lease Payments	Operating Leases AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) 2020 $ 269.9 $ 16.0 $ 2.2 $ 18.3 $ 97.0 $ 16.2 $ 7.3 $ 8.6 2021 253.6 15.3 1.2 15.7 92.9 14.2 6.4 8.2 2022 245.6 14.2 0.6 14.7 92.8 13.5 6.0 7.6 2023 74.8 13.0 0.1 11.9 10.1 12.3 5.6 6.4 2024 62.0 11.4 — 9.0 8.6 10.7 4.8 5.0 Later Years 169.7 26.0 — 20.0 21.0 36.5 12.0 11.8 Total Future Minimum Lease Payments 1,075.6 95.9 4.1 89.6 322.4 103.4 42.1 47.6 Less: Imputed Interest 106.9 12.8 0.1 10.4 23.5 14.9 5.3 6.4 Estimated Present Value of Future Minimum Lease Payments $ 968.7 $ 83.1 $ 4.0 $ 79.2 $ 298.9 $ 88.5 $ 36.8 $ 41.2
Future Minimum Lease Payments		Finance Leases AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) 2019 $ 70.8 $ 5.8 $ 0.1 $ 9.0 $ 8.2 $ 3.3 $ 3.4 $ 13.1 2020 60.2 5.3 — 8.0 7.2 2.7 2.6 11.5 2021 51.7 4.7 — 7.3 6.6 2.3 2.0 10.5 2022 43.8 4.2 — 6.8 6.1 1.7 1.6 9.4 2023 35.5 3.7 — 6.3 5.7 1.2 1.4 8.6 Later Years 90.2 10.1 — 13.3 21.7 2.8 3.3 18.7 Total Future Minimum Lease Payments 352.2 33.8 0.1 50.7 55.5 14.0 14.3 71.8 Less: Imputed Interest 63.2 5.3 — 10.9 16.8 1.9 2.0 11.0 Estimated Present Value of Future Minimum Lease Payments $ 289.0 $ 28.5 $ 0.1 $ 39.8 $ 38.7 $ 12.1 $ 12.3 $ 60.8 Operating Leases AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) 2019 $ 259.6 $ 15.1 $ 2.3 $ 17.6 $ 92.6 $ 14.5 $ 6.5 $ 7.4 2020 250.1 14.1 1.8 16.5 89.3 13.2 6.0 7.2 2021 232.7 13.2 1.0 13.9 84.8 10.9 5.0 6.7 2022 222.5 12.2 0.5 12.8 83.8 10.0 4.6 6.1 2023 58.3 10.8 0.1 9.9 6.5 8.8 4.1 5.0 Later Years 165.2 28.4 — 20.5 19.5 31.7 10.7 11.7 Total Future Minimum Lease Payments $ 1,188.4 $ 93.8 $ 5.7 $ 91.2 $ 376.5 $ 89.1 $ 36.9 $ 44.1
Maximum Potential Loss	Company Maximum Potential Loss (in millions) AEP $ 47.3 AEP Texas 11.3 APCo 6.6 I&M 4.1 OPCo 7.3 PSO 4.2 SWEPCo 4.8
Future Minimum Lease Payments	Future Minimum Lease Payments AEP (a) I&M (in millions) 2020 $ 147.8 $ 73.9 2021 147.8 73.9 2022 147.5 73.7 Total Future Minimum Lease Payments $ 443.1 $ 221.5 (a) AEP’s future minimum lease payments include equal shares from AEGCo and I&M.

Financing Activities (Tables)

Financing Activities (Tables)	12 Months Ended
	Dec. 31, 2019
AEP Common Stock	Shares of AEP Common Stock Issued Held in Treasury Balance, December 31, 2016 512,048,520 20,336,592 Issued 162,124 — Treasury Stock Reissued — (131,546 ) (a) Balance, December 31, 2017 512,210,644 20,205,046 Issued 1,239,392 — Treasury Stock Reissued — (886 ) (a) Balance, December 31, 2018 513,450,036 20,204,160 Issued 923,595 — Balance, December 31, 2019 514,373,631 20,204,160 (a) Reissued Treasury Stock used to fulfill share commitments related to AEP’s Share-based Compensation. See “Shared-based Compensation Plans” section of Note 15 for additional information.
Long-term Debt	Weighted-Average Interest Rate Ranges as of Outstanding as of Interest Rate as of December 31, December 31, Company Maturity December 31, 2019 2019 2018 2019 2018 AEP (in millions) Senior Unsecured Notes 2019-2050 4.29% 2.15%-8.13% 2.15%-8.13% $ 21,180.7 $ 18,903.3 Pollution Control Bonds (a) 2019-2038 (b) 2.75% 1.35%-5.38% 1.60%-6.30% 1,998.8 1,643.8 Notes Payable – Nonaffiliated (c) 2019-2032 3.27% 2.42%-6.37% 3.20%-6.37% 234.3 204.7 Securitization Bonds 2019-2029 (d) 3.23% 1.98%-5.31% 1.98%-5.31% 1,025.1 1,111.4 Spent Nuclear Fuel Obligation (e) 279.8 273.6 Junior Subordinated Notes (f) 2022 3.40% 3.40% 787.8 — Other Long-term Debt 2019-2059 3.03% 1.15%-13.718% 1.15%-13.718% 1,219.0 1,209.9 Total Long-term Debt Outstanding $ 26,725.5 $ 23,346.7 AEP Texas Senior Unsecured Notes 2019-2050 4.01% 2.40%-6.76% 2.40%-6.76% $ 3,090.9 $ 2,398.4 Pollution Control Bonds 2020-2030 3.63% 1.75%-4.55% 1.75%-6.30% 490.3 490.9 Securitization Bonds 2020-2029 (d) 3.25% 1.98%-5.31% 1.98%-5.31% 776.8 791.2 Other Long-term Debt 2019-2059 3.06% 3.05%-4.50% 3.94%-4.50% 200.4 200.8 Total Long-term Debt Outstanding $ 4,558.4 $ 3,881.3 AEPTCo Senior Unsecured Notes 2019-2049 3.86% 3.10%-5.52% 2.68%-5.52% $ 3,427.3 $ 2,823.0 Total Long-term Debt Outstanding $ 3,427.3 $ 2,823.0 APCo Senior Unsecured Notes 2021-2049 5.12% 3.30%-7.00% 3.30%-7.00% $ 3,442.7 $ 3,047.3 Pollution Control Bonds (a) 2019-2038 (b) 2.64% 1.67%-5.38% 1.70%-5.38% 546.1 616.0 Securitization Bonds 2023-2028 (d) 3.17% 2.008%-3.772% 2.008%-3.772% 248.3 272.3 Other Long-term Debt 2019-2026 3.14% 2.97%-13.718% 3.74%-13.718% 126.7 127.0 Total Long-term Debt Outstanding $ 4,363.8 $ 4,062.6 I&M Senior Unsecured Notes 2023-2048 4.38% 3.20%-6.05% 3.20%-6.05% $ 2,150.7 $ 2,149.0 Pollution Control Bonds (a) 2019-2025 (b) 2.55% 1.79%-3.05% 1.81%-3.05% 240.0 264.5 Notes Payable – Nonaffiliated (c) 2019-2024 2.49% 2.42%-2.80% 3.20%-3.38% 168.7 135.8 Spent Nuclear Fuel Obligation (e) 279.8 273.6 Other Long-term Debt 2021-2025 3.09% 2.93%-6.00% 3.66%-6.00% 211.0 212.5 Total Long-term Debt Outstanding $ 3,050.2 $ 3,035.4 OPCo Senior Unsecured Notes 2021-2049 5.20% 4.00%-6.60% 4.15%-6.60% $ 2,081.0 $ 1,635.5 Pollution Control Bonds 2038 5.80% — 32.3 Securitization Bonds 2019 (d) 2.049% — 47.8 Other Long-term Debt 2028 1.15% 1.15% 1.15% 1.0 1.0 Total Long-term Debt Outstanding $ 2,082.0 $ 1,716.6 PSO Senior Unsecured Notes 2019-2049 4.55% 3.05%-6.625% 3.05%-6.625% $ 1,245.6 $ 1,144.9 Pollution Control Bonds 2020 4.45% 4.45% 4.45% 12.7 12.6 Other Long-term Debt 2019-2027 3.19% 3.00%-3.20% 3.00%-3.72% 127.9 129.5 Total Long-term Debt Outstanding $ 1,386.2 $ 1,287.0 SWEPCo Senior Unsecured Notes 2022-2048 4.04% 2.75%-6.20% 2.75%-6.20% $ 2,428.9 $ 2,427.0 Pollution Control Bonds 2019 1.60% — 53.5 Notes Payable – Nonaffiliated (c) 2024-2032 5.26% 4.58%-6.37% 4.58%-6.37% 65.6 68.9 Other Long-term Debt 2020-2035 3.55% 3.08%-4.68% 3.75%-4.68% 161.1 164.0 Total Long-term Debt Outstanding $ 2,655.6 $ 2,713.4 (a) For certain series of Pollution Control Bonds, interest rates are subject to periodic adjustment. Certain series may be purchased on demand at periodic interest adjustment dates. Letters of credit from banks and insurance policies support certain series. (b) Certain Pollution Control Bonds are subject to redemption earlier than the maturity date. Consequently, these bonds have been classified for maturity purposes as Long-term Debt Due Within One Year - Nonaffiliated on the balance sheets. (c) Notes payable represent outstanding promissory notes issued under term loan agreements and credit agreements with a number of banks and other financial institutions. At expiration, all notes then issued and outstanding are due and payable. Interest rates are both fixed and variable. Variable rates generally relate to specified short-term interest rates. (d) Dates represent the scheduled final payment dates for the securitization bonds. The legal maturity date is one to two years later. These bonds have been classified for maturity and repayment purposes based on the scheduled final payment date. (e) Spent Nuclear Fuel Obligation consists of a liability along with accrued interest for disposal of SNF. See “Spent Nuclear Fuel Disposal” section of Note 6 for additional information. (f) See “Equity Units” section below for additional information.
Long-term Debt 5-Year Maturity	AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) 2020 $ 1,598.7 $ 392.1 $ — $ 215.6 $ 139.7 $ 0.1 $ 13.2 $ 121.2 2021 2,022.7 88.7 50.0 393.0 291.5 500.1 250.5 6.2 2022 3,014.6 (a) 716.0 104.0 355.4 26.8 0.1 125.5 281.2 2023 739.9 218.5 60.0 26.6 259.2 0.1 0.6 6.2 2024 706.5 96.0 95.0 113.5 4.2 0.1 0.6 31.2 After 2024 18,863.1 3,081.4 3,156.0 3,296.9 2,355.3 1,600.5 1,001.4 2,231.7 Principal Amount 26,945.5 4,592.7 3,465.0 4,401.0 3,076.7 2,101.0 1,391.8 2,677.7 Unamortized Discount, Net and Debt Issuance Costs (220.0 ) (34.3 ) (37.7 ) (37.2 ) (26.5 ) (19.0 ) (5.6 ) (22.1 ) Total Long-term Debt Outstanding $ 26,725.5 $ 4,558.4 $ 3,427.3 $ 4,363.8 $ 3,050.2 $ 2,082.0 $ 1,386.2 $ 2,655.6 (a) Amount includes $805 million of Junior Subordinated Notes. See “Equity Units” section below for additional information.
Dividend Payment Restrictions	AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Restricted Retained Earnings $ 1,741.4 (a) $ 385.0 $ — $ 26.3 $ 524.5 $ — $ 153.0 $ 534.5 (a) Includes the restrictions of consolidated and non-consolidated subsidiaries.
Lines of Credit and Short-term Debt	December 31, 2019 2018 Company Type of Debt Outstanding Amount Interest Rate (a) Outstanding Amount Interest Rate (a) (in millions) (in millions) AEP Securitized Debt for Receivables (b) $ 710.0 2.42 % $ 750.0 2.16 % AEP Commercial Paper 2,110.0 2.10 % 1,160.0 2.96 % SWEPCo Notes Payable 18.3 3.29 % — — % Total Short-term Debt $ 2,838.3 $ 1,910.0 (a) Weighted-average rate. (b) Amount of securitized debt for receivables as accounted for under the “Transfers and Servicing” accounting guidance.
Utility Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits	Year Ended December 31, 2019 : Maximum Average Net Loans to Borrowings Maximum Borrowings Average (Borrowings from) Authorized from the Loans to the from the Loans to the the Utility Money Short-term Utility Utility Utility Utility Pool as of Borrowing Company Money Pool Money Pool Money Pool Money Pool December 31, 2019 Limit (in millions) AEP Texas $ 390.7 $ 213.1 $ 239.3 $ 194.4 $ 199.7 $ 500.0 AEPTCo 374.9 244.4 152.0 52.8 (119.0 ) 795.0 (a) APCo 270.0 232.2 115.9 51.9 (214.6 ) 500.0 I&M 158.8 66.0 71.5 16.2 (101.2 ) 500.0 OPCo 291.2 178.6 129.2 50.1 (131.0 ) 500.0 PSO 140.5 215.6 63.9 98.3 38.8 300.0 SWEPCo 105.1 81.4 53.3 13.6 (59.9 ) 350.0 Year Ended December 31, 2018 : Maximum Average Net Loans to Borrowings Maximum Borrowings Average (Borrowings from) Authorized from the Loans to the from the Loans to the the Utility Money Short-term Utility Utility Utility Utility Pool as of Borrowing Company Money Pool Money Pool Money Pool Money Pool December 31, 2018 Limit (in millions) AEP Texas $ 390.6 $ 106.9 $ 176.0 $ 47.1 $ (216.0 ) $ 500.0 AEPTCo 371.3 276.4 177.9 58.4 35.8 795.0 (a) APCo 295.5 23.7 175.3 23.3 (182.6 ) 600.0 I&M 322.1 657.8 255.5 110.7 11.6 500.0 OPCo 270.8 225.0 167.8 189.4 (114.1 ) 500.0 PSO 193.7 31.8 104.5 12.9 (105.5 ) 300.0 SWEPCo 200.1 533.7 143.2 268.1 81.4 350.0 (a) Amount represents the combined authorized short-term borrowing limit the State Transcos have from FERC or state regulatory commissions.
Nonutility Money Pool Activity	Year Ended December 31, 2019 : Maximum Loans Average Loans Loans to the Nonutility to the Nonutility to the Nonutility Money Pool as of Company Money Pool Money Pool December 31, 2019 (in millions) AEP Texas $ 8.0 $ 7.7 $ 7.5 SWEPCo 2.1 2.0 2.1 Year Ended December 31, 2018 : Maximum Loans Average Loans Loans to the Nonutility to the Nonutility to the Nonutility Money Pool as of Company Money Pool Money Pool December 31, 2018 (in millions) AEP Texas $ 8.4 $ 8.1 $ 8.0 SWEPCo 2.0 2.0 2.0
Direct Borrowing Activity	Year Ended December 31, 2019 : Maximum Maximum Average Average Borrowings from Loans to Authorized Borrowings Loans Borrowings Loans AEP as of AEP as of Short-term from AEP to AEP from AEP to AEP December 31, 2019 December 31, 2019 Borrowing Limit (in millions) $ 1.3 $ 153.5 $ 1.3 $ 68.0 $ 1.3 $ 68.7 $ 75.0 (a) Year Ended December 31, 2018 : Maximum Maximum Average Average Borrowings from Loans to Authorized Borrowings Loans Borrowings Loans AEP as of AEP as of Short-term from AEP to AEP from AEP to AEP December 31, 2018 December 31, 2018 Borrowing Limit (in millions) $ 1.2 $ 104.7 $ 1.1 $ 49.8 $ 1.2 $ 16.9 $ 75.0 (a) (a) Amount represents the combined authorized short-term borrowing limit the State Transcos have from FERC or state regulatory commissions.
Maximum and Minimum Interest Rates for Funds Either Borrowed from or Loaned to Utility Money Pool	Years Ended December 31, 2019 2018 2017 Maximum Interest Rate 3.43 % 2.97 % 1.85 % Minimum Interest Rate 1.77 % 1.81 % 0.92 %
Average Interest Rates for Funds Borrowed from and Loaned to Utility Money Pool	Average Interest Rate for Funds Borrowed from the Utility Money Pool for the Years Ended December 31, Average Interest Rate for Funds Loaned to the Utility Money Pool for the Years Ended December 31, Company 2019 2018 2017 2019 2018 2017 AEP Texas 2.63 % 2.26 % 1.29 % 2.03 % 2.29 % 1.26 % AEPTCo 2.64 % 2.27 % 1.36 % 2.41 % 2.10 % 1.27 % APCo 2.45 % 2.26 % 1.28 % 2.66 % 2.21 % 1.29 % I&M 2.34 % 2.16 % 1.27 % 2.60 % 2.08 % 1.29 % OPCo 2.67 % 2.18 % 1.37 % 2.68 % 2.47 % 0.98 % PSO 2.85 % 2.27 % 1.32 % 2.27 % 1.98 % — % SWEPCo 2.72 % 2.31 % 1.28 % 2.22 % 2.00 % 0.98 %
Maximum, Minimum and Average Interest Rates for Funds Borrowed from and Loaned to the Nonutility Money Pool	Maximum Interest Rate Minimum Interest Rate Average Interest Rate Year Ended for Funds Loaned to for Funds Loaned to for Funds Loaned to December 31, Company the Nonutility Money Pool the Nonutility Money Pool the Nonutility Money Pool 2019 AEP Texas 3.02 % 1.91 % 2.56 % 2019 SWEPCo 3.02 % 1.91 % 2.55 % 2018 AEP Texas 2.97 % 1.83 % 2.36 % 2018 SWEPCo 2.97 % 1.83 % 2.36 % 2017 AEP Texas 1.85 % — % 1.32 % 2017 SWEPCo 1.85 % — % 1.32 %
Maximum Minimum and Average Interest Rates for Funds Borrowed from and Loaned to AEP	Maximum Minimum Maximum Minimum Average Average Interest Rate Interest Rate Interest Rate Interest Rate Interest Rate Interest Rate for Funds for Funds for Funds for Funds for Funds for Funds Year Ended Borrowed from Borrowed from Loaned to Loaned to Borrowed from Loaned to December 31, AEP AEP AEP AEP AEP AEP 2019 3.02 % 1.91 % 3.02 % 1.91 % 2.55 % 2.51 % 2018 2.97 % 1.76 % 2.97 % 1.76 % 2.36 % 2.36 % 2017 1.85 % 0.92 % 1.85 % 0.92 % 1.33 % 1.36 %
Comparative Accounts Receivable Information	Years Ended December 31, 2019 2018 2017 (dollars in millions) Effective Interest Rates on Securitization of Accounts Receivable 2.42 % 2.16 % 1.22 % Net Uncollectible Accounts Receivable Written Off $ 26.6 $ 27.6 $ 23.4
Customer Accounts Receivable Managed Portfolio	December 31, 2019 2018 (in millions) Accounts Receivable Retained Interest and Pledged as Collateral Less Uncollectible Accounts $ 841.8 $ 972.5 Short-term – Securitized Debt of Receivables 710.0 750.0 Delinquent Securitized Accounts Receivable 39.6 50.3 Bad Debt Reserves Related to Securitization 32.1 27.5 Unbilled Receivables Related to Securitization 266.8 281.4
Accounts Receivable and Accrued Unbilled Revenues	December 31, Company 2019 2018 (in millions) APCo $ 120.9 $ 133.3 I&M 141.8 152.9 OPCo 330.3 395.2 PSO 101.1 109.7 SWEPCo 125.2 150.3
Fees Paid to AEP Credit for Customer Accounts Receivable Sold	Years Ended December 31, Company 2019 2018 2017 (in millions) APCo $ 7.4 $ 7.0 $ 5.6 I&M 11.1 9.2 6.7 OPCo 27.1 26.3 21.7 PSO 7.8 7.9 7.0 SWEPCo 10.2 8.9 7.2
Proceeds on Sale of Receivables to AEP Credit	Years Ended December 31, Company 2019 2018 2017 (in millions) APCo $ 1,310.3 $ 1,421.0 $ 1,372.8 I&M 1,824.2 1,843.0 1,612.9 OPCo 2,293.6 2,674.5 2,339.0 PSO 1,442.5 1,484.6 1,337.0 SWEPCo 1,618.5 1,736.1 1,563.4

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance Units and Reinvested Dividends on Outstanding Performance Units	Years Ended December 31, Performance Shares 2019 2018 2017 Awarded Shares (in thousands) 535.0 581.4 590.7 Weighted Average Share Fair Value at Grant Date $ 83.21 $ 67.21 $ 69.78 Vesting Period (in years) 3 3 3 Performance Shares and AEP Career Shares (Reinvested Dividends Portion) Years Ended December 31, 2019 2018 2017 Awarded Shares (in thousands) (a) 66.4 80.2 74.6 Weighted Average Fair Value at Grant Date $ 88.73 $ 70.58 $ 72.35 Vesting Period (in years) (b) (b) (b) (a) All awarded dividends in 2019 were equity awards and awarded dividends in both 2018 and 2017 were a mix of equity awards and liability awards. (b) The vesting period for the reinvested dividends on performance shares is equal to the remaining life of the related performance shares. Dividends on AEP career shares vest immediately when the dividend is awarded but are not settled in AEP common stock until after the participant’s AEP employment ends.
Summary of Performance Scores and Performance Units Earned	Years Ended December 31, Performance Shares 2019 2018 2017 Certified Performance Score 132.7 % 136.7 % 164.8 % Performance Shares Earned 792,897 820,780 956,055 Performance Shares Mandatorily Deferred as AEP Career Shares 10,063 11,248 20,213 Performance Shares Voluntarily Deferred into the Incentive Compensation Deferral Program 49,392 56,826 47,177 Performance Shares to be Settled (a) 733,442 752,706 888,665 (a) Performance shares settled for the three-year period ended December 31, 2019 settled in AEP common stock. Performance units settled for the three-year period ended December 31, 2018 and 2017 settled in cash.
Summary of Cash Payouts for Performance Units and Career Shares	Years Ended December 31, Performance Units and AEP Career Shares 2019 2018 2017 (in millions) Cash Settlements for Performance Units $ 58.3 $ 66.9 $ 64.9 AEP Common Stock Settlements for Career Share Distributions 6.6 5.1 0.4
Status of Nonvested Performance Units	Nonvested Performance Shares Shares Weighted Average Grant Date Fair Value (in thousands) Nonvested as of January 1, 2019 1,171.3 $ 66.01 Granted 582.5 80.30 Vested (a) (597.5 ) 65.42 Forfeited (42.9 ) 70.32 Nonvested as of December 31, 2019 1,113.4 73.64 (a) The vested Performance Shares will be converted to 733 thousand shares based on the closing share price on the day before settlement.
Monte Carlo Valuation Assumptions	Years Ended December 31, Monte Carlo Valuation 2019 2018 2017 Valuation Period (in years) (a) 2.87 2.87 2.86 Expected Volatility Minimum 14.83 % 14.77 % 15.65 % Expected Volatility Maximum 25.57 % 26.72 % 27.19 % Expected Volatility Average 17.39 % 17.90 % 19.07 % Dividend Rate (b) — % — % — % Risk Free Rate 2.49 % 2.34 % 1.44 % (a) Period from award date to vesting date. (b) Equivalent to reinvesting dividends.
Summary of Units Awarded and Fair Value of Restricted Stock Units	Years Ended December 31, Restricted Stock Units 2019 2018 2017 Awarded Units (in thousands) 304.8 260.0 255.8 Weighted Average Grant Date Fair Value $ 81.57 $ 67.96 $ 65.26
Total Fair Value and Total Intrinsic Value of Restricted Shares and Restricted Stock Units Vested	Years Ended December 31, Restricted Stock Units 2019 2018 2017 (in millions) Fair Value of Restricted Stock Units Vested $ 16.3 $ 16.6 $ 16.1 Intrinsic Value of Restricted Stock Units Vested (a) 21.6 19.2 20.0 (a) Intrinsic value is calculated as market price at exercise date.
Status of Nonvested Restricted Shares and Restricted Stock Units	Nonvested Restricted Stock Units Shares/Units Weighted Average Grant Date Fair Value (in thousands) Nonvested as of January 1, 2019 489.1 $ 66.01 Granted 304.8 81.57 Vested (253.7 ) 64.44 Forfeited (23.3 ) 70.27 Nonvested as of December 31, 2019 516.9 75.55
Stock Unit Accumulation Plan for Non-employee Directors	Years Ended December 31, Stock Unit Accumulation Plan for Non-Employee Directors 2019 2018 2017 Awarded Units (in thousands) 10.0 11.4 14.8 Weighted Average Grant Date Fair Value $ 89.13 $ 70.41 $ 70.79
Compensation Cost and Actual Tax Benefit Realized for Tax Deductions from Compensation Cost for Share-based Payment Arrangements	Years Ended December 31, Share-based Compensation Plans 2019 2018 2017 (in millions) Compensation Cost for Share-based Payment Arrangements (a) $ 57.9 $ 53.2 $ 79.5 Actual Tax Benefit (b) 8.4 7.7 18.9 Total Compensation Cost Capitalized 20.0 19.7 26.4 (a) Compensation cost for share-based payment arrangements is included in Other Operation and Maintenance expenses on the statements of income. (b) In December 2017, Tax Reform modified Section 162(m) of the Internal Revenue Code. Beginning after 2017, AEP can generally no longer deduct certain compensation expense in excess of $1 million for certain named executive officers. This will reduce the tax benefit going forward.

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2019
Affiliated Revenues	Related Party Revenues AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Year Ended December 31, 2019 Direct Sales to East Affiliates $ — $ — $ 128.6 $ — $ — $ — $ — Direct Sales to West Affiliates — — — — — — — Auction Sales to OPCo (a) — — 11.4 6.7 — — — Direct Sales to AEPEP 157.2 — — — — — (0.1 ) Transmission Revenues — 795.5 58.5 0.7 7.7 1.3 3.6 Other Revenues 3.3 11.2 6.8 3.1 19.6 4.8 1.4 Total Affiliated Revenues $ 160.5 $ 806.7 $ 205.3 $ 10.5 $ 27.3 $ 6.1 $ 4.9 Related Party Revenues AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Year Ended December 31, 2018 Direct Sales to East Affiliates $ — $ — $ 133.2 $ 0.1 $ — $ — $ — Direct Sales to West Affiliates — — — — — — — Auction Sales to OPCo (a) — — 5.8 7.1 — — — Direct Sales to AEPEP 103.6 — — — — — — Transmission Revenues — 591.4 36.4 11.7 3.9 0.9 26.9 Other Revenues 1.6 7.5 6.0 3.2 17.1 4.5 1.5 Total Affiliated Revenues $ 105.2 $ 598.9 $ 181.4 $ 22.1 $ 21.0 $ 5.4 $ 28.4 Related Party Revenues AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Year Ended December 31, 2017 Direct Sales to East Affiliates $ — $ — $ 130.4 $ — $ — $ — $ — Direct Sales to West Affiliates — — — 3.8 — — — Auction Sales to OPCo (a) — — 1.0 — — — — Direct Sales to AEPEP 63.6 — — — — — (0.2 ) Transmission Revenues — 559.6 34.1 (4.4 ) 6.2 — 24.2 Other Revenues 2.1 8.5 6.5 2.4 18.2 4.3 1.9 Total Affiliated Revenues $ 65.7 $ 568.1 $ 172.0 $ 1.8 $ 24.4 $ 4.3 $ 25.9 (a) Refer to the Ohio Auctions section below for further information regarding these amounts.
Affiliated Purchases	Related Party Purchases I&M OPCo (in millions) Year Ended December 31, 2019 Auction Purchases from AEPEP (a) $ — $ 64.6 Auction Purchases from AEP Energy (a) — 69.9 Auction Purchases from AEPSC (a) — 21.5 Direct Purchases from AEGCo 214.9 — Total Affiliated Purchases $ 214.9 $ 156.0 Related Party Purchases I&M OPCo (in millions) Year Ended December 31, 2018 Auction Purchases from AEPEP (a) $ — $ 79.7 Auction Purchases from AEP Energy (a) — 41.0 Auction Purchases from AEPSC (a) — 14.6 Direct Purchases from AEGCo 237.9 — Total Affiliated Purchases $ 237.9 $ 135.3 Related Party Purchases I&M OPCo (in millions) Year Ended December 31, 2017 Auction Purchases from AEPEP (a) $ — $ 96.5 Auction Purchases from AEP Energy (a) — 5.5 Auction Purchases from AEPSC (a) — 6.5 Direct Purchases from AEGCo 223.9 — Total Affiliated Purchases $ 223.9 $ 108.5 (a) Refer to the Ohio Auctions section below for further information regarding this amount.
PJM Transmission Service Charges	Years Ended December 31, Company 2019 2018 2017 (in millions) APCo $ 222.3 $ 128.3 $ 158.2 I&M 143.5 91.4 103.8 OPCo 373.4 210.1 248.6
SPP Transmission Service Charges	Years Ended December 31, Company 2019 2018 2017 (in millions) PSO $ 46.9 $ 65.9 $ 56.0 SWEPCo 20.1 10.5 6.6
Joint License Agreement	Years Ended December 31, Billing Company 2019 2018 2017 (in millions) APCo $ 0.2 $ — $ — I&M 1.5 2.2 1.4 KPCo 0.3 0.2 0.2 OPCo 2.2 2.9 2.4 PSO 0.3 0.3 0.3 WPCo 0.1 — —
Railcar Maintenance	Years Ended December 31, Company 2019 2018 2017 (in millions) I&M $ 1.3 $ 1.5 $ 1.3 PSO 0.8 0.7 0.5 SWEPCo 4.0 3.4 3.5
Barging, Urea Transloading and Other Services	Years Ended December 31, Company 2019 2018 2017 (in millions) AEGCo $ 14.9 $ 19.9 $ 15.3 AGR — — 0.1 APCo 38.9 35.1 37.2 KPCo 4.8 4.2 5.0 WPCo 4.8 4.2 5.0
Central Machine Shop	Years Ended December 31, Company 2019 2018 2017 (in millions) AGR $ 0.8 $ 1.6 $ 1.2 I&M 2.3 2.4 2.7 KPCo 1.4 1.7 1.8 PSO 1.1 0.5 1.1 SWEPCo 1.1 0.7 0.8
Related Party Sales of Property	Sales Years Ended December 31, Company 2019 2018 2017 (in millions) AEP Texas $ 0.9 $ 0.3 $ 0.2 APCo 5.5 5.4 3.5 I&M 7.5 8.2 5.0 OPCo 7.0 10.7 2.9 PSO 0.8 1.0 1.5 SWEPCo 0.2 0.8 0.5
Related Party Purchases of Property	Purchases Years Ended December 31, Company 2019 2018 2017 (in millions) AEP Texas $ 0.3 $ 0.1 $ 0.4 AEPTCo 10.2 18.5 9.1 APCo 6.0 0.6 0.9 I&M 0.9 2.0 3.5 OPCo 3.0 2.8 1.6 PSO 0.5 1.3 0.2 SWEPCo 0.7 0.8 0.4
Charitable Contribution to AEP Foundation [Table Text Block]	Year Ended December 31, Company 2019 (in millions) AEP $ 50.0 AEP Texas 6.2 AEPTCo 6.5 APCo 8.9 I&M 9.0 OPCo 5.4 PSO 3.4 SWEPCo 5.5

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	12 Months Ended
	Dec. 31, 2019
Consolidated Assets And Liabilities Of Variable Interest Entities	American Electric Power Company, Inc. and Subsidiary Companies Variable Interest Entities December 31, 2019 Registrant Subsidiaries SWEPCo Sabine I&M DCC Fuel AEP Texas Transition Funding AEP Texas Restoration Funding OPCo APCo (in millions) ASSETS Current Assets $ 80.0 $ 86.5 $ 187.0 $ 9.4 $ — $ 21.5 Net Property, Plant and Equipment 111.6 156.8 — — — — Other Noncurrent Assets 93.2 82.5 428.1 (a) 234.4 (b) — 237.5 (c) Total Assets $ 284.8 $ 325.8 $ 615.1 $ 243.8 $ — $ 259.0 LIABILITIES AND EQUITY Current Liabilities $ 50.6 $ 86.4 $ 280.2 $ 16.3 $ — $ 28.3 Noncurrent Liabilities 233.6 239.4 316.3 226.3 — 228.8 Equity 0.6 — 18.6 1.2 — 1.9 Total Liabilities and Equity $ 284.8 $ 325.8 $ 615.1 $ 243.8 $ — $ 259.0 (a) Includes an intercompany item eliminated in consolidation of $39 million . (b) Includes an intercompany item eliminated in consolidation of $1 million . (c) Includes an intercompany item eliminated in consolidation of $3 million . American Electric Power Company, Inc. and Subsidiary Companies Variable Interest Entities December 31, 2019 Other Consolidated VIEs AEP Credit Protected Cell of EIS Transource Energy Desert Sky and Trent Apple Blossom and Black Oak Santa Rita East (in millions) ASSETS Current Assets $ 842.8 $ 194.6 $ 25.8 $ 7.8 $ 10.1 $ 17.7 Net Property, Plant and Equipment — — 424.1 330.6 231.4 465.2 Other Noncurrent Assets 7.1 — 3.2 10.1 13.1 0.3 Total Assets $ 849.9 $ 194.6 $ 453.1 $ 348.5 $ 254.6 $ 483.2 LIABILITIES AND EQUITY Current Liabilities $ 805.2 $ 40.7 $ 192.4 $ 5.5 $ 5.4 $ 3.9 Noncurrent Liabilities 0.9 78.0 4.8 15.8 4.7 7.5 Equity 43.8 75.9 255.9 327.2 244.5 471.8 Total Liabilities and Equity $ 849.9 $ 194.6 $ 453.1 $ 348.5 $ 254.6 $ 483.2 American Electric Power Company, Inc. and Subsidiary Companies Variable Interest Entities December 31, 2018 Registrant Subsidiaries SWEPCo Sabine I&M DCC Fuel AEP Texas Transition Funding OPCo APCo (in millions) ASSETS Current Assets $ 70.0 $ 77.6 $ 192.8 $ 29.5 $ 24.8 Net Property, Plant and Equipment 106.9 122.3 — — — Other Noncurrent Assets 98.5 58.4 683.5 (a) 24.2 (b) 261.8 (c) Total Assets $ 275.4 $ 258.3 $ 876.3 $ 53.7 $ 286.6 LIABILITIES AND EQUITY Current Liabilities $ 31.1 $ 77.1 $ 271.9 $ 48.5 $ 28.0 Noncurrent Liabilities 244.0 181.2 586.1 3.9 256.7 Equity 0.3 — 18.3 1.3 1.9 Total Liabilities and Equity $ 275.4 $ 258.3 $ 876.3 $ 53.7 $ 286.6 (a) Includes an intercompany item eliminated in consolidation of $47 million . (b) Includes an intercompany item eliminated in consolidation of $11 million . (c) Includes an intercompany item eliminated in consolidation of $3 million . American Electric Power Company, Inc. and Subsidiary Companies Variable Interest Entities December 31, 2018 Other Consolidated VIEs AEP Credit Protected Cell of EIS Transource Energy Desert Sky and Trent (in millions) ASSETS Current Assets $ 974.2 $ 177.8 $ 25.7 $ 6.8 Net Property, Plant and Equipment — — 380.3 348.5 Other Noncurrent Assets 6.3 0.1 1.9 — Total Assets $ 980.5 $ 177.9 $ 407.9 $ 355.3 LIABILITIES AND EQUITY Current Liabilities $ 923.5 $ 38.6 $ 19.9 $ 8.7 Noncurrent Liabilities 0.8 85.3 160.3 6.2 Equity 56.2 54.0 227.7 340.4 Total Liabilities and Equity $ 980.5 $ 177.9 $ 407.9 $ 355.3
SWEPCo's Investment In DHLC	December 31, 2019 2018 As Reported on the Balance Sheet Maximum Exposure As Reported on the Balance Sheet Maximum Exposure (in millions) Capital Contribution from SWEPCo $ 7.6 $ 7.6 $ 7.6 $ 7.6 Retained Earnings 17.5 17.5 14.5 14.5 SWEPCo’s Share of Obligations — 130.0 — 167.6 Total Investment in DHLC $ 25.1 $ 155.1 $ 22.1 $ 189.7
AEP's Investment In OVEC	December 31, 2019 2018 As Reported on the Balance Sheet Maximum Exposure As Reported on Maximum Exposure (in millions) Capital Contribution from AEP $ 4.4 $ 4.4 $ 4.4 $ 4.4 AEP’s Ratio of OVEC Debt (a) — 588.9 — 604.1 Total Investment in OVEC $ 4.4 $ 593.3 $ 4.4 $ 608.5 (a) Based on the Registrants’ power participation ratios APCo, I&M and OPCo’s share of OVEC debt was $213 million , $106 million and $270 million as of December 31, 2019 and $218 million , $109 million and $277 million as of December 31, 2018
Purchased Power from OVEC	Years Ended December 31, Company 2019 2018 2017 (in millions) APCo $ 104.5 $ 100.4 $ 101.0 I&M 52.3 50.2 50.5 OPCo 132.7 127.5 128.2
AEP's Investment In PATH-WV	December 31, 2019 2018 As Reported on the Balance Sheet Maximum Exposure As Reported on Maximum Exposure (in millions) Capital Contribution from Parent $ 18.8 $ 18.8 $ 18.8 $ 18.8 Retained Earnings (1.7 ) (1.7 ) (1.4 ) (1.4 ) Total Investment in PATH-WV $ 17.1 $ 17.1 $ 17.4 $ 17.4
Billings from Significant Variable Interest	Years Ended December 31, Company 2019 2018 2017 (in millions) AEP Texas $ 206.6 $ 184.3 $ 152.6 AEPTCo 242.3 220.4 188.9 APCo 308.3 295.6 268.8 I&M 184.8 173.5 176.0 OPCo 230.4 214.9 195.7 PSO 125.7 121.5 114.7 SWEPCo 169.5 164.4 150.7
Carrying Amount and Classification of Variable Interest in Accounts Payable	December 31, 2019 2018 Company As Reported on the Balance Sheet Maximum Exposure As Reported on the Balance Sheet Maximum Exposure (in millions) AEP Texas $ 32.4 $ 32.4 $ 22.3 $ 22.3 AEPTCo 33.4 33.4 24.6 24.6 APCo 44.1 44.1 32.2 32.2 I&M 28.6 28.6 23.8 23.8 OPCo 33.2 33.2 23.9 23.9 PSO 18.1 18.1 13.2 13.2 SWEPCo 23.4 23.4 18.4 18.4

Property, Plant and Equipment_2

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2019
Property, Plant and Equipment	December 31, 2019 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Regulated Property, Plant and Equipment Generation $ 21,323.5 (a) $ — $ — $ 6,563.7 $ 5,099.7 $ — $ 1,574.6 $ 4,691.4 (a) Transmission 24,763.4 4,466.5 8,137.9 3,584.1 1,641.8 2,686.3 948.5 2,056.5 Distribution 22,440.8 4,215.2 — 4,201.7 2,437.6 5,323.5 2,684.8 2,270.7 Other 4,369.6 803.4 268.2 542.0 590.9 754.7 337.2 520.6 CWIP 4,261.2 (a) 763.9 1,485.7 593.4 382.3 394.4 133.4 210.1 (a) Less: Accumulated Depreciation 18,778.1 1,465.0 402.3 4,425.6 3,281.4 2,261.7 1,579.9 2,766.2 Total Regulated Property, Plant and Equipment - Net 58,380.4 8,784.0 9,489.5 11,059.3 6,870.9 6,897.2 4,098.6 6,983.1 Nonregulated Property, Plant and Equipment - Net 1,757.7 61.1 1.4 22.6 28.8 9.8 4.7 112.1 Total Property, Plant and Equipment - Net $ 60,138.1 $ 8,845.1 $ 9,490.9 $ 11,081.9 $ 6,899.7 $ 6,907.0 $ 4,103.3 $ 7,095.2 December 31, 2018 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Regulated Property, Plant and Equipment Generation $ 20,989.1 (a) $ — $ — $ 6,509.6 $ 4,887.2 $ — $ 1,577.0 $ 4,672.6 (a) Transmission 21,500.5 3,683.6 6,515.8 3,317.7 1,576.8 2,544.3 892.3 1,866.9 Distribution 21,192.8 4,043.2 — 3,989.4 2,249.7 4,942.3 2,572.8 2,178.6 Other 3,770.8 724.6 172.6 457.4 543.1 563.7 298.1 485.2 CWIP 4,352.6 (a) 836.0 1,578.3 490.2 465.3 432.1 94.0 194.7 (a) Less: Accumulated Depreciation 17,743.1 1,431.2 271.9 4,118.9 3,139.4 2,217.7 1,472.1 2,633.5 Total Regulated Property, Plant and Equipment - Net 54,062.7 7,856.2 7,994.8 10,645.4 6,582.7 6,264.7 3,962.1 6,764.5 Nonregulated Property, Plant and Equipment - Net 1,036.4 135.6 1.4 22.9 28.5 10.2 4.6 107.3 Total Property, Plant and Equipment - Net $ 55,099.1 $ 7,991.8 $ 7,996.2 $ 10,668.3 $ 6,611.2 $ 6,274.9 $ 3,966.7 $ 6,871.8 (a) AEP and SWEPCo’s regulated generation and regulated CWIP include amounts related to SWEPCo’s Arkansas jurisdictional share of the Turk Plant.
Depreciation, Depletion and Amortization - Regulated	AEP 2019 2018 2017 Functional Class of Property Annual Composite Depreciation Rate Ranges Depreciable Life Ranges Annual Composite Depreciation Rate Ranges Depreciable Life Ranges Annual Composite Depreciation Rate Ranges Depreciable Life Ranges (in years) (in years) (in years) Generation 2.5% - 5.5% 20 - 132 2.4% - 4.0% 20 - 132 2.3% - 3.7% 20 - 132 Transmission 1.8% - 2.6% 15 - 81 1.6% - 2.7% 15 - 81 1.6% - 2.7% 15 - 100 Distribution 2.7% - 3.7% 7 - 78 2.7% - 3.6% 7 - 78 2.7% - 3.7% 5 - 156 Other 2.6% - 9.5% 5 - 75 2.3% - 9.8% 5 - 75 2.3% - 9.2% 5 - 84 AEP Texas 2019 2018 2017 Functional Class of Property Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges (in years) (in years) (in years) Transmission 1.8% 45 - 81 1.7% 45 - 81 1.7% 45 - 81 Distribution 3.5% 7 - 70 3.6% 7 - 70 3.6% 7 - 70 Other 6.3% 5 - 50 6.0% 5 - 50 8.7% 5 - 50 AEPTCo 2019 2018 2017 Functional Class of Property Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges (in years) (in years) (in years) Transmission 2.0% 24 - 75 1.9% 20 - 75 1.7% 20 - 100 Other 5.8% 5 - 64 5.6% 5 - 64 6.7% 5 - 84 APCo 2019 2018 2017 Functional Class of Property Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges (in years) (in years) (in years) Generation 3.2% 35 - 118 3.1% 35 - 112 3.1% 35 - 112 Transmission 1.8% 15 - 71 1.6% 15 - 68 1.6% 15 - 68 Distribution 3.7% 12 - 57 3.6% 10 - 57 3.7% 10 - 57 Other 7.2% 5 - 55 7.4% 5 - 55 6.5% 5 - 55 I&M 2019 2018 2017 Functional Class of Property Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges (in years) (in years) (in years) Generation 4.0% 20 - 132 3.4% 20 - 132 2.4% 20 - 132 Transmission 1.9% 50 - 73 1.8% 50 - 73 1.7% 50 - 75 Distribution 3.4% 9 - 75 3.1% 9 - 75 2.7% 10 - 70 Other 9.4% 5 - 50 8.9% 5 - 50 8.4% 5 - 45 OPCo 2019 2018 2017 Functional Class of Property Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges (in years) (in years) (in years) Transmission 2.3% 39 - 60 2.3% 39 - 60 2.3% 39 - 60 Distribution 3.1% 14 - 65 3.0% 14 - 65 2.8% 5 - 57 Other 4.9% 5 - 50 6.3% 5 - 50 6.2% 5 - 50 PSO 2019 2018 2017 Functional Class of Property Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges (in years) (in years) (in years) Generation 2.9% 35 - 75 2.9% 35 - 75 2.4% 35 - 85 Transmission 2.4% 45 - 75 2.3% 45 - 75 2.2% 45 - 100 Distribution 2.9% 15 - 78 2.9% 15 - 78 2.7% 27 - 156 Other 5.6% 5 - 64 6.3% 5 - 64 7.4% 5 - 84 SWEPCo 2019 2018 2017 Functional Class of Property Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges Annual Composite Depreciation Rate Depreciable Life Ranges (in years) (in years) (in years) Generation 2.5% 40 - 70 2.4% 40 - 70 2.3% 40 - 70 Transmission 2.4% 50 - 73 2.2% 50 - 73 2.3% 50 - 73 Distribution 2.7% 25 - 70 2.7% 25 - 70 2.7% 25 - 70 Other 7.6% 5 - 55 8.0% 5 - 55 7.2% 5 - 55
Depreciation, Depletion and Amortization - Unregulated	2019 2018 2017 Functional Class of Property Annual Composite Depreciation Rate Ranges Depreciable Life Ranges Annual Composite Depreciation Rate Ranges Depreciable Life Ranges Annual Composite Depreciation Rate Ranges Depreciable Life Ranges (in years) (in years) (in years) Generation 3.2% - 21.2% 15 - 59 3.4% - 22.3% 15 - 59 2.4% - 5.1% 15 - 66 Transmission 2.5% 30 - 40 2.4% 40 0.2% 40 Distribution 2.3% 40 2.3% 40 2.3% 40 Other 17.6% 5 - 50 (a) 16.3% 5 - 50 (a) 12.1% 5 - 50 (a) (a) SWEPCo’s nonregulated property, plant and equipment is depreciated using the straight-line method over a range of 3 to 20 years.
Asset Retirement Obligation (ARO)	Company ARO as of December 31, 2018 Accretion Expense Liabilities Incurred Liabilities Settled Revisions in Cash Flow Estimates (a) ARO as of December 31, 2019 (in millions) AEP (b)(c)(d)(e) $ 2,355.5 $ 102.5 $ 12.0 $ (118.1 ) $ 67.0 $ 2,418.9 AEP Texas (b)(e) 27.9 1.3 — (0.2 ) 0.1 29.1 APCo (b)(e) 116.1 5.9 — (17.6 ) 6.7 111.1 I&M (b)(c)(e) 1,681.3 67.4 — (0.2 ) 0.1 1,748.6 OPCo (e) 1.8 0.1 — (0.3 ) 0.2 1.8 PSO (b)(e) 46.9 3.1 — (0.4 ) 2.6 52.2 SWEPCo (b)(d)(e) 206.8 10.3 — (11.8 ) 6.9 212.2 Company ARO as of December 31, 2017 Accretion Expense Liabilities Incurred Liabilities Settled Revisions in Cash Flow Estimates (a) ARO as of December 31, 2018 (in millions) AEP (b)(c)(d)(e) $ 2,005.7 $ 93.7 $ 0.8 $ (87.0 ) $ 342.3 (f) $ 2,355.5 AEP Texas (b)(e) 26.7 1.2 — (0.1 ) 0.1 27.9 APCo (b)(e) 125.0 6.6 — (17.3 ) 1.8 116.1 I&M (b)(c)(e) 1,321.8 58.7 — (0.2 ) 301.0 (f) 1,681.3 OPCo (e) 1.7 0.1 — — — 1.8 PSO (b)(e) 54.0 3.2 — (0.4 ) (9.9 ) 46.9 SWEPCo (b)(d)(e) 169.2 9.1 0.2 (11.7 ) 40.0 206.8 (a) Primarily related to ash ponds, landfills and mine reclamation, generally due to changes in estimated closure area, volumes and/or unit costs. (b) Includes ARO related to ash disposal facilities. (c) Includes ARO related to nuclear decommissioning costs for the Cook Plant of $1.73 billion and $1.66 billion as of December 31, 2019 and 2018 , respectively. (d) Includes ARO related to Sabine and DHLC. (e) Includes ARO related to asbestos removal. (f) Revision for Cook Plant related to a new third-party study, which impacted the ARO liability for changes of estimated cash flows and application of a new discount rate.
Allowance For Equity Funds Used During Construction	Years Ended December 31, Company 2019 2018 2017 (in millions) AEP $ 168.4 $ 132.5 $ 93.7 AEP Texas 15.2 20.0 6.8 AEPTCo 84.3 70.6 49.0 APCo 16.6 13.2 9.2 I&M 19.4 11.9 11.1 OPCo 18.2 9.8 6.4 PSO 2.7 0.4 0.5 SWEPCo 6.8 6.0 2.4
Allowance For Borrowed Funds Used During Construction	Years Ended December 31, Company 2019 2018 2017 (in millions) AEP $ 88.7 $ 73.6 $ 48.6 AEP Texas 20.0 18.4 6.8 AEPTCo 32.2 26.1 20.2 APCo 9.3 8.4 5.3 I&M 8.9 7.4 6.7 OPCo 6.7 5.8 3.8 PSO 1.9 0.9 1.1 SWEPCo 4.0 4.8 2.1
Jointly-owned Electric Facilities	Registrant’s Share as of December 31, 2019 Fuel Type Percent of Ownership Utility Plant in Service Construction Work in Progress Accumulated Depreciation (in millions) AEP Conesville Generating Station, Unit 4 (a)(h) Coal 83.5 % $ — $ — $ — Dolet Hills Power Station, Unit 1 (f) Lignite 40.2 % 337.3 6.2 216.5 Flint Creek Generating Station, Unit 1 (g) Coal 50.0 % 374.3 3.4 101.1 Pirkey Generating Station, Unit 1 (g) Lignite 85.9 % 607.8 7.7 416.8 Oklaunion Power Station (e) Coal 70.3 % 106.6 0.1 91.7 Turk Generating Plant (g) Coal 73.3 % 1,593.3 1.7 225.8 Total $ 3,019.3 $ 19.1 $ 1,051.9 AEP Texas Oklaunion Power Station (e) Coal 54.7 % $ 351.7 $ — $ 291.9 I&M Rockport Generating Plant (b)(c)(d) Coal 50.0 % $ 1,114.2 $ 105.5 $ 586.2 PSO Oklaunion Power Station (e) Coal 15.6 % $ 106.6 $ 0.1 $ 91.7 SWEPCo Dolet Hills Power Station, Unit 1 (f) Lignite 40.2 % $ 337.3 $ 6.2 $ 216.5 Flint Creek Generating Station, Unit 1 (g) Coal 50.0 % 374.3 3.4 101.1 Pirkey Generating Station, Unit 1 (g) Lignite 85.9 % 607.8 7.7 416.8 Turk Generating Plant (g) Coal 73.3 % 1,593.3 1.7 225.8 Total $ 2,912.7 $ 19.0 $ 960.2 Registrant’s Share as of December 31, 2018 Fuel Type Percent of Ownership Utility Plant in Service Construction Work in Progress Accumulated Depreciation (in millions) AEP Conesville Generating Station, Unit 4 (a)(h) Coal 83.5 % $ 16.4 $ 0.2 $ 2.4 Dolet Hills Power Station, Unit 1 (f) Lignite 40.2 % 336.2 5.1 209.6 Flint Creek Generating Station, Unit 1 (g) Coal 50.0 % 375.1 1.6 88.9 Pirkey Generating Station, Unit 1 (g) Lignite 85.9 % 591.3 16.6 418.0 Oklaunion Power Station (e) Coal 70.3 % 106.4 — 67.8 Turk Generating Plant (g) Coal 73.3 % 1,590.5 1.1 197.5 Total $ 3,015.9 $ 24.6 $ 984.2 AEP Texas Oklaunion Power Station (e) Coal 54.7 % $ 352.1 $ 0.2 $ 218.6 I&M Rockport Generating Plant (b)(c)(d) Coal 50.0 % $ 1,108.7 $ 50.2 $ 514.1 PSO Oklaunion Power Station (e) Coal 15.6 % $ 106.4 $ — $ 67.8 SWEPCo Dolet Hills Power Station, Unit 1 (f) Lignite 40.2 % $ 336.2 $ 5.1 $ 209.6 Flint Creek Generating Station, Unit 1 (g) Coal 50.0 % 375.1 1.6 88.9 Pirkey Generating Station, Unit 1 (g) Lignite 85.9 % 591.3 16.6 418.0 Turk Generating Plant (g) Coal 73.3 % 1,590.5 1.1 197.5 Total $ 2,893.1 $ 24.4 $ 914.0 (a) Operated by AGR. (b) Operated by I&M. (c) Amounts include I&M’s 50% ownership of both Unit 1 and capital additions for Unit 2. Unit 2 is subject to an operating lease with a nonaffiliated company. See the “Rockport Lease” section of Note 13 . (d) AEGCo owns 50% of Unit 1 with I&M and 50% of capital additions for Unit 2. (e) Operated by PSO, which owns 15.6% . Also jointly-owned ( 54.7% ) by AEP Texas and various nonaffiliated companies. (f) Operated by CLECO, a nonaffiliated company. (g) Operated by SWEPCo. (h) Conesville Generating Station, Unit 4 was impaired as of December 31, 2019. See the “Impairments” section of Note 7

Goodwill (Tables)

Goodwill (Tables)	12 Months Ended
	Dec. 31, 2019
Changes in Carrying Amount of Goodwill	Corporate and Other Generation & Marketing AEP Consolidated (in millions) Balance as of December 31, 2017 $ 37.1 $ 15.4 $ 52.5 Impairment Losses — — — Balance as of December 31, 2018 37.1 15.4 52.5 Impairment Losses — — — Balance as of December 31, 2019 $ 37.1 $ 15.4 $ 52.5

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	12 Months Ended
	Dec. 31, 2019
Disaggregated Revenues from Contracts with Customers	Year Ended December 31, 2019 Vertically Integrated Utilities Transmission and Distribution Utilities AEP Transmission Holdco Generation & Marketing Corporate and Other Reconciling Adjustments AEP Consolidated (in millions) Retail Revenues: Residential Revenues $ 3,643.7 $ 2,069.9 $ — $ — $ — $ — $ 5,713.6 Commercial Revenues 2,155.3 1,152.9 — — — — 3,308.2 Industrial Revenues 2,179.0 429.1 — — — (0.9 ) 2,607.2 Other Retail Revenues 179.1 43.8 — — — — 222.9 Total Retail Revenues 8,157.1 3,695.7 — — — (0.9 ) 11,851.9 Wholesale and Competitive Retail Revenues: Generation Revenues (b) 807.6 — — 254.8 — — 1,062.4 Transmission Revenues (a) 292.1 435.1 1,077.2 — — (825.0 ) 979.4 Renewable Generation Revenues (c) — — — 57.3 — — 57.3 Retail, Trading and Marketing Revenues (b) — — — 1,480.7 — (135.6 ) 1,345.1 Total Wholesale and Competitive Retail Revenues 1,099.7 435.1 1,077.2 1,792.8 — (960.6 ) 3,444.2 Other Revenues from Contracts with Customers (c) 168.2 169.4 16.6 4.9 104.7 (147.1 ) 316.7 Total Revenues from Contracts with Customers 9,425.0 4,300.2 1,093.8 1,797.7 104.7 (1,108.6 ) 15,612.8 Other Revenues: Alternative Revenues (c) (57.9 ) 32.3 (20.6 ) — — (66.9 ) (113.1 ) Other Revenues (c) — 150.0 — 59.9 (8.9 ) (139.3 ) 61.7 Total Other Revenues (57.9 ) 182.3 (20.6 ) 59.9 (8.9 ) (206.2 ) (51.4 ) Total Revenues $ 9,367.1 $ 4,482.5 $ 1,073.2 $ 1,857.6 $ 95.8 $ (1,314.8 ) $ 15,561.4 (a) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $794 million . The remaining affiliated amounts were immaterial. (b) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $136 million . The remaining affiliated amounts were immaterial. (c) Amounts include affiliated and nonaffiliated revenues. Year Ended December 31, 2018 Vertically Integrated Utilities Transmission and Distribution Utilities AEP Transmission Holdco Generation & Marketing Corporate and Other Reconciling Adjustments AEP Consolidated (in millions) Retail Revenues: Residential Revenues $ 3,751.8 $ 2,189.4 $ — $ — $ — $ — $ 5,941.2 Commercial Revenues 2,183.4 1,251.7 — — — — 3,435.1 Industrial Revenues 2,212.8 512.5 — — — — 2,725.3 Other Retail Revenues 183.5 42.7 — — — — 226.2 Total Retail Revenues (a) 8,331.5 3,996.3 — — — — 12,327.8 Wholesale and Competitive Retail Revenues: Generation Revenues (d) 899.8 — — 423.7 — (7.3 ) (e) 1,316.2 Transmission Revenues (b) 282.2 372.1 849.3 — — (737.1 ) 766.5 Renewable Generation Revenues (d) — — — 50.8 — — 50.8 Retail, Trading and Marketing Revenues (c) — — — 1,422.9 — (120.7 ) 1,302.2 Total Wholesale and Competitive Retail Revenues 1,182.0 372.1 849.3 1,897.4 — (865.1 ) 3,435.7 Other Revenues from Contracts with Customers (d) 158.4 204.6 15.2 20.6 86.2 (32.0 ) 453.0 Total Revenues from Contracts with Customers 9,671.9 4,573.0 864.5 1,918.0 86.2 (897.1 ) 16,216.5 Other Revenues: Alternative Revenues (d) (15.9 ) (22.2 ) (60.4 ) — — 52.7 (45.8 ) Other Revenues (d) (10.5 ) 102.3 — 22.3 8.9 (98.0 ) (e) 25.0 Total Other Revenues (26.4 ) 80.1 (60.4 ) 22.3 8.9 (45.3 ) (20.8 ) Total Revenues $ 9,645.5 $ 4,653.1 $ 804.1 $ 1,940.3 $ 95.1 $ (942.4 ) $ 16,195.7 (a) 2018 amounts have been revised to reflect the reclassification of certain customer accounts between Retail classes. This reclassification did not impact previously reported Total Retail Revenues. Management concluded that these prior period disclosure only errors were immaterial individually and in the aggregate. (b) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $643 million . The remaining affiliated amounts were immaterial. (c) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $121 million . The remaining affiliated amounts were immaterial. (d) Amounts include affiliated and nonaffiliated revenues. (e) 2018 amounts have been revised to reflect the reclassification of $98 million of affiliated revenues between Generation Revenues and Other Revenues. This reclassification did not impact previously reported Total Revenues. Management concluded that these prior period disclosure only errors were immaterial individually and in the aggregate. Year Ended December 31, 2019 AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Retail Revenues: Residential Revenues $ 571.5 $ — $ 1,266.9 $ 730.0 $ 1,502.0 $ 650.2 $ 638.6 Commercial Revenues 411.5 — 559.9 494.2 738.5 388.5 485.4 Industrial Revenues 129.4 — 592.2 550.7 299.9 303.5 338.7 Other Retail Revenues 29.9 — 75.2 7.3 13.1 81.6 9.0 Total Retail Revenues 1,142.3 — 2,494.2 1,782.2 2,553.5 1,423.8 1,471.7 Wholesale Revenues: Generation Revenues (a) — — 251.5 402.4 — 39.5 194.7 Transmission Revenues (b) 379.2 1,025.5 103.6 25.1 56.0 27.5 106.7 Total Wholesale Revenues 379.2 1,025.5 355.1 427.5 56.0 67.0 301.4 Other Revenues from Contracts with Customers (c) 30.1 16.6 61.8 98.4 139.3 22.0 26.1 Total Revenues from Contracts with Customers 1,551.6 1,042.1 2,911.1 2,308.1 2,748.8 1,512.8 1,799.2 Other Revenues: Alternative Revenues (d) 0.6 (20.7 ) 13.6 (1.4 ) 31.7 (31.0 ) (48.3 ) Other Revenues (d) 157.1 — — — 17.1 — — Total Other Revenues 157.7 (20.7 ) 13.6 (1.4 ) 48.8 (31.0 ) (48.3 ) Total Revenues $ 1,709.3 $ 1,021.4 $ 2,924.7 $ 2,306.7 $ 2,797.6 $ 1,481.8 $ 1,750.9 (a) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $129 million primarily relating to the PPA with KGPCo. The remaining affiliated amounts were immaterial. (b) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEPTCo was $782 million . The remaining affiliated amounts were immaterial. (c) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $73 million primarily relating to the barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial. (d) Amounts include affiliated and nonaffiliated revenues. Year Ended December 31, 2018 AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Retail Revenues: Residential Revenues $ 578.9 $ — $ 1,342.7 $ 730.0 $ 1,611.6 $ 659.0 $ 641.6 Commercial Revenues 414.7 — 580.4 485.0 835.6 394.2 483.9 Industrial Revenues 128.0 — 604.3 565.6 385.2 304.0 333.7 Other Retail Revenues 29.4 — 77.4 7.2 12.9 83.6 8.6 Total Retail Revenues (a) 1,151.0 — 2,604.8 1,787.8 2,845.3 1,440.8 1,467.8 Wholesale Revenues: Generation Revenues (b) — — 250.4 470.5 — 36.3 216.8 Transmission Revenues (c) 313.4 816.9 82.7 23.1 58.5 40.2 108.4 Total Wholesale Revenues 313.4 816.9 333.1 493.6 58.5 76.5 325.2 Other Revenues from Contracts with Customers (d) 28.6 15.1 55.3 99.6 176.1 19.1 24.0 Total Revenues from Contracts with Customers 1,493.0 832.0 2,993.2 2,381.0 3,079.9 1,536.4 1,817.0 Other Revenues: Alternative Revenues (e) (1.3 ) (55.9 ) (23.8 ) (2.1 ) (20.8 ) 10.9 4.9 Other Revenues (e) 103.6 — (1.9 ) (8.2 ) 4.3 — — Total Other Revenues 102.3 (55.9 ) (25.7 ) (10.3 ) (16.5 ) 10.9 4.9 Total Revenues $ 1,595.3 $ 776.1 $ 2,967.5 $ 2,370.7 $ 3,063.4 $ 1,547.3 $ 1,821.9 (a) 2018 amounts have been revised to reflect the reclassification of certain customer accounts between Retail classes. This reclassification did not impact previously reported Total Retail Revenues. Management concluded that these prior period disclosure only errors were immaterial individually and in the aggregate. (b) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $134 million primarily relating to the PPA with KGPCo. The remaining affiliated amounts were immaterial. (c) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEPTCo was $646 million . The remaining affiliated amounts were immaterial. (d) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $70 million primarily relating to the barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial. (e) Amounts include affiliated and nonaffiliated revenues.
Fixed Performance Obligations	Company 2020 2021-2022 2023-2024 After 2024 Total (in millions) AEP $ 953.0 $ 160.8 $ 160.6 $ 223.5 $ 1,497.9 AEP Texas 387.0 — — — 387.0 AEPTCo 1,090.7 — — — 1,090.7 APCo 158.0 32.3 23.2 11.6 225.1 I&M 29.6 8.8 8.8 4.4 51.6 OPCo 61.0 — — — 61.0 PSO 11.7 — — — 11.7 SWEPCo 30.4 — — — 30.4
Affiliated Accounts Receivable Contracts with Customers	Years Ended December 31, Company 2019 2018 (in millions) AEPTCo $ 65.9 $ 58.6 APCo 47.3 52.5 I&M 37.1 35.3 OPCo 33.9 46.1 PSO 9.7 12.4 SWEPCo 17.6 16.3

Unaudited Quarterly Financial_2

Unaudited Quarterly Financial Information (Tables)	12 Months Ended
	Dec. 31, 2019
Schedule of Quarterly Financial Information	Quarterly Periods Ended: AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) March 31, 2019 Total Revenues $ 4,056.8 $ 390.7 $ 243.5 $ 792.8 $ 614.3 $ 836.8 $ 332.8 $ 421.1 Operating Income 788.4 70.8 141.6 152.1 115.0 162.5 20.9 54.1 Net Income 574.1 34.4 104.3 133.7 98.9 128.0 6.2 29.0 Earnings Attributable to Common Shareholders 572.8 NA NA NA NA NA NA 27.8 June 30, 2019 Total Revenues $ 3,573.6 $ 438.0 $ 266.9 $ 655.8 $ 543.1 $ 606.6 $ 348.1 $ 375.5 Operating Income 551.0 38.7 161.0 76.9 77.9 77.1 56.6 33.0 Net Income 459.1 80.6 136.0 55.5 60.3 50.6 41.9 7.3 Earnings Attributable to Common Shareholders 461.3 NA NA NA NA NA NA 6.2 September 30, 2019 Total Revenues $ 4,315.0 $ 489.3 $ 259.7 $ 755.5 $ 611.1 $ 710.6 $ 493.0 $ 545.5 Operating Income 958.2 118.2 142.3 142.6 107.3 98.6 120.0 134.7 Net Income 733.9 77.0 107.6 104.3 88.8 69.1 100.3 111.3 Earnings Attributable to Common Shareholders 733.5 NA NA NA NA NA NA 110.5 December 31, 2019 Total Revenues $ 3,616.0 $ 391.3 $ 251.3 $ 720.6 $ 538.2 $ 643.6 $ 307.9 $ 408.8 Operating Income 294.7 4.3 122.3 25.7 40.6 63.0 1.8 33.9 Net Income (Loss) 152.7 (13.7 ) 91.8 12.8 21.4 49.4 (10.8 ) 14.6 Earnings Attributable to Common Shareholders 153.5 NA NA NA NA NA NA 14.1 Quarterly Periods Ended: AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) March 31, 2018 Total Revenues $ 4,048.3 $ 371.6 $ 191.7 $ 820.4 $ 576.8 $ 790.9 $ 336.8 $ 419.4 Operating Income 706.0 81.8 111.1 193.0 97.4 117.3 3.9 41.6 Net Income (Loss) 456.7 46.8 84.1 125.5 64.2 79.6 (7.2 ) 13.4 Earnings Attributable to Common Shareholders 454.4 NA NA NA NA NA NA 11.8 June 30, 2018 Total Revenues $ 4,013.2 $ 388.3 $ 200.1 $ 667.0 $ 589.7 $ 748.8 $ 398.3 $ 457.1 Operating Income 757.0 86.2 110.5 132.6 117.4 104.4 57.2 70.5 Net Income 530.1 46.5 82.0 77.4 94.7 68.8 36.6 38.7 Earnings Attributable to Common Shareholders 528.4 NA NA NA NA NA NA 37.6 September 30, 2018 Total Revenues $ 4,333.1 $ 433.4 $ 194.4 $ 762.0 $ 629.7 $ 778.3 $ 481.4 $ 535.3 Operating Income 668.6 94.0 97.0 49.8 110.2 79.9 78.5 127.1 Net Income 579.7 57.8 78.1 87.1 72.7 88.7 60.4 89.6 Earnings Attributable to Common Shareholders 577.6 NA NA NA NA NA NA 88.2 December 31, 2018 Total Revenues $ 3,801.1 $ 402.0 $ 189.9 $ 718.1 $ 574.5 $ 745.4 $ 330.8 $ 410.1 Operating Income 551.1 84.3 91.5 108.1 52.2 118.2 2.9 38.5 Net Income (Loss) 364.8 60.2 71.7 77.8 29.7 88.4 (6.6 ) 10.5 Earnings Attributable to Common Shareholders 363.4 NA NA NA NA NA NA 9.6 NA Not applicable. 2019 Quarterly Periods Ended March 31 June 30 September 30 December 31 Earnings Attributable to AEP Common Shareholders (in millions) $ 572.8 $ 461.3 $ 733.5 $ 153.5 Basic Earnings per Share Attributable to AEP Common Shareholders from Continuing Operations (a) 1.16 0.93 1.49 0.31 Diluted Earnings per Share Attributable to AEP Common Shareholders from Continuing Operations (a) 1.16 0.93 1.48 0.31 2018 Quarterly Periods Ended March 31 June 30 September 30 December 31 Earnings Attributable to AEP Common Shareholders (in millions) $ 454.4 $ 528.4 $ 577.6 $ 363.4 Basic Earnings per Share Attributable to AEP Common Shareholders from Continuing Operations (a) 0.92 1.07 1.17 0.74 Diluted Earnings per Share Attributable to AEP Common Shareholders from Continuing Operations (a) 0.92 1.07 1.17 0.74 (a) Quarterly Earnings per Share amounts are intended to be stand-alone calculations and are not always additive to full-year amount due to rounding.

Organization and Summary of S_4

Organization and Summary of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Materials and Supplies	$ 640.7				$ 602.1				$ 640.7	$ 602.1
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period				$ 234.1					234.1
Supplemental Income Statement Elements
Depreciation and Amortization of Property, Plant and Equipment									2,203.7	1,965	$ 1,709.1
Amortization of Certain Securitized Assets									280.7	287.9	275.9
Amortization of Regulatory Assets and Liabilities									30.1	33.7	12.2
Utilities Operating Expense, Depreciation and Amortization									2,514.5	2,286.6	1,997.2
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts									1,022.5	939.3	858.3
Income Taxes Paid, Net									6.1	(24.7)	(1.1)
Construction in Progress Expenditures Incurred but Not yet Paid									1,341.1	1,120.4	1,330.8
Noncash Investing and Financing Activities:
Lease Obligation Incurred									87.5	55.6	60.7
Construction Expenditures Included in Current Liabilities as of December 31,									1,341.1	1,120.4	1,330.8
Construction Expenditures Included in Noncurrent Liabilities as of December 31,									0	0	71.8
Acquisition of Nuclear Fuel Included in Current Liabilities as of December 31,									0.1	4	0
Noncash Contribution of Assets by Noncontrolling Interest									0	84	0
Expected Reimbursement For Spent Nuclear Fuel Dry Cask Storage									0.3	2.2	2.6
Noncontrolling Interest Assumed with Sempra Renewables LLC and Santa Rita East Acquisition									32.4	0	0
Restricted Cash	185.8				210				185.8	210
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	432.6				444.1				432.6	444.1	412.6	$ 403.5
Amounts Attributable to AEP Common Shareholders
Net Income (Loss) Attributable to Noncontrolling Interests									(1.3)	7.5	16.3
Net Income (Loss)	$ 153.5	$ 733.5	$ 461.3	$ 572.8	$ 363.4	$ 577.6	$ 528.4	$ 454.4	$ 1,921.1	$ 1,923.8	$ 1,912.6
Weighted Average Number of Basic AEP Common Shares Outstanding									493,694,345	492,774,600	491,814,651
Earnings Per Share, Basic									$ 3.89	$ 3.90	$ 3.89
BASIC EARNINGS PER SHARE ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS FROM CONTINUING OPERATIONS	$ 0.31	$ 1.49	$ 0.93	$ 1.16	$ 0.74	$ 1.17	$ 1.07	$ 0.92
Weighted Average Dilutive Effect of:
Weighted Average Number of Diluted AEP Common Shares Outstanding									495,306,238	493,758,277	492,611,067
Earnings Per Share, Diluted									$ 3.88	$ 3.90	$ 3.88
DILUTED EARNINGS PER SHARE ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS FROM CONTINUING OPERATIONS	$ 0.31	$ 1.48	$ 0.93	$ 1.16	$ 0.74	$ 1.17	$ 1.07	$ 0.92
Revenues
TOTAL REVENUES	$ 3,616	$ 4,315	$ 3,573.6	$ 4,056.8	$ 3,801.1	$ 4,333.1	$ 4,013.2	$ 4,048.3	$ 15,561.4	$ 16,195.7	$ 15,424.9
Expenses
Depreciation and Amortization									2,514.5	2,286.6	1,997.2
TOTAL EXPENSES									12,969.1	13,513	11,899.9
OPERATING INCOME (LOSS)	294.7	958.2	551	788.4	551.1	668.6	757	706	2,592.3	2,682.7	3,525
Other Income (Expense)
Allowance for Equity Funds Used During Construction									168.4	132.5	93.7
Interest Expense									(1,072.5)	(984.4)	(895)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)									1,834.8	1,973.5	2,816.2
Income Tax Expense (Benefit)									(12.9)	115.3	969.7
NET INCOME (LOSS)	152.7	733.9	459.1	574.1	364.8	579.7	530.1	456.7	1,919.8	1,931.3	1,928.9
Accounts Receivable:
Customers	625.3				699				625.3	699
Total Accounts Receivable	1,705.1				1,926.5				1,705.1	1,926.5
TOTAL CURRENT ASSETS	4,077.8				4,113.9				4,077.8	4,113.9
Property, Plant and Equipment
Transmission	24,808.6				21,531				24,808.6	21,531
Other Property, Plant and Equipment	4,811.5				4,265				4,811.5	4,265
Construction Work in Progress	4,319.8				4,393.9				4,319.8	4,393.9
Total Property, Plant and Equipment	79,145.7				73,085.2				79,145.7	73,085.2
Accumulated Depreciation and Amortization	19,007.6				17,986.1				19,007.6	17,986.1
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	60,138.1				55,099.1				60,138.1	55,099.1
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS	11,676.4				9,589.8				11,676.4	9,589.8
TOTAL ASSETS	75,892.3				68,802.8				75,892.3	68,802.8	64,729.1
Current Liabilities
Accounts Payable	2,085.8				1,874.3				2,085.8	1,874.3
Accrued Taxes	1,357.8				1,218				1,357.8	1,218
TOTAL CURRENT LIABILITIES	10,299.1				8,648.8				10,299.1	8,648.8
Liabilities, Noncurrent
Deferred Income Taxes	7,588.2				7,086.5				7,588.2	7,086.5
Regulatory Liabilities and Deferred Investment Tax Credits	8,457.6				8,540.3				8,457.6	8,540.3
TOTAL NONCURRENT LIABILITIES	45,571.4				40,985.8				45,571.4	40,985.8
TOTAL LIABILITIES	55,870.5				49,634.6				55,870.5	49,634.6
Equity [Abstract]
Retained Earnings	9,900.9				9,325.3				9,900.9	9,325.3
TOTAL LIABILITIES AND EQUITY	75,892.3				68,802.8				75,892.3	68,802.8
Operating Activites
NET INCOME (LOSS)	152.7	733.9	459.1	574.1	364.8	579.7	530.1	456.7	1,919.8	1,931.3	1,928.9
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization									2,514.5	2,286.6	1,997.2
Deferred Income Taxes									(17.8)	104.3	901.5
Allowance for Equity Funds Used During Construction									(168.4)	(132.5)	(93.7)
Amortization of Deferred Property Taxes									(73.8)	(59.1)	(29.5)
Change in Other Noncurrent Assets									(97.4)	119.8	(423.9)
Increase (Decrease) in Other Noncurrent Liabilities									(116.1)	129	181.7
Accounts Receivable, Net									247.8	145.9	28.5
Accounts Payable									5.8	36.6	(58)
Accrued Taxes, Net									138.9	153.2	91.9
Net Cash Flows from (Used for) Operating Activities									4,270.1	5,223.2	4,270.4
Investing Activities
Net Cash Flows from (Used for) Investing Activities									(7,144.5)	(6,353.6)	(3,656.4)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from (Used for) Financing Activities									2,862.9	1,161.9	(604.9)
Cash and Cash Equivalents at Beginning of Period				234.1					234.1
Cash and Cash Equivalents at End of Period	246.8				234.1				246.8	234.1
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt									4,536.6	4,945.7	3,854.1
Repayments of Long-term Debt									1,220.8	2,782	3,087.9
Equity Method Investment	1,356.6				846.2				1,356.6	846.2
Income (Loss) from Equity Method Investment									$ 72.1	$ 73.1	$ 82.4
Antidilutive Shares Outstanding									0	0	0
Net Income (Loss)	152.7	733.9	459.1	574.1	364.8	579.7	530.1	456.7	$ 1,919.8	$ 1,931.3	$ 1,928.9
Retained Earnings	$ 9,900.9				9,325.3				$ 9,900.9	9,325.3
Berkshire Hathaway [Member]
Organization and Summary of Significant Accounting Policies (Textuals)
Equity Method Investment, Ownership Percentage	50.00%								50.00%
AEP Transmission Holdco [Member]
Organization and Summary of Significant Accounting Policies (Textuals)
Equity Method Investment, Ownership Percentage	49.50%								49.50%
AEP Transmission Partner [Member]
Organization and Summary of Significant Accounting Policies (Textuals)
Equity Method Investment, Ownership Percentage	0.50%								0.50%
Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation	30.00%								30.00%
Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation	54.00%								54.00%
Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation	15.00%								15.00%
Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation	1.00%								1.00%
Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation	48.00%								48.00%
Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation	50.00%								50.00%
Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation	2.00%								2.00%
Pension and Other Postretirement Benefit Plans [Member]
Securities Loaned	$ 246				241				$ 246	241
AEP Texas Inc. [Member]
Materials and Supplies	56.7				52.8				56.7	52.8
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period				3.1					3.1
Supplemental Income Statement Elements
Depreciation and Amortization of Property, Plant and Equipment									365.9	262.2	221.1
Amortization of Certain Securitized Assets									258.7	240	231.4
Amortization of Regulatory Assets and Liabilities									(2.3)	(2.6)	(2.4)
Utilities Operating Expense, Depreciation and Amortization									622.3	499.6	450.1
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts									148.6	145.9	134.6
Income Taxes Paid, Net									(11)	7.9	(28.3)
Construction in Progress Expenditures Incurred but Not yet Paid									225.5	243.1	325.7
Noncash Investing and Financing Activities:
Construction Expenditures Included in Current Liabilities as of December 31,									225.5	243.1	325.7
Restricted Cash	154.7				156.7				154.7	156.7
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	157.8				159.8				$ 157.8	$ 159.8	$ 157.2	146.9
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk									10.00%	10.00%	10.00%
Revenues
TOTAL REVENUES	391.3	489.3	438	390.7	402	433.4	388.3	371.6	$ 1,709.3	$ 1,595.3	$ 1,538.4
Expenses
Depreciation and Amortization									622.3	499.6	450.1
TOTAL EXPENSES									1,477.3	1,249	1,122.3
OPERATING INCOME (LOSS)	4.3	118.2	38.7	70.8	84.3	94	86.2	81.8	232	346.3	416.1
Other Income (Expense)
Allowance for Equity Funds Used During Construction									15.2	20	6.8
Interest Expense									(137.2)	(147.3)	(142.3)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)									124.7	232.1	287.1
Income Tax Expense (Benefit)									(53.6)	20.8	(23.4)
NET INCOME (LOSS)	(13.7)	77	80.6	34.4	60.2	57.8	46.5	46.8	178.3	211.3	310.5
Accounts Receivable:
Customers	116				110.9				116	110.9
Total Accounts Receivable	193.4				196.9				193.4	196.9
Accrued Tax Benefits	66.1				44.9				66.1	44.9
TOTAL CURRENT ASSETS	692.9				476.5				692.9	476.5
Property, Plant and Equipment
Transmission	4,466.5				3,683.6				4,466.5	3,683.6
Other Property, Plant and Equipment	805.9				727.9				805.9	727.9
Construction Work in Progress	763.9				836.2				763.9	836.2
Total Property, Plant and Equipment	10,603.2				9,643				10,603.2	9,643
Accumulated Depreciation and Amortization	1,758.1				1,651.2				1,758.1	1,651.2
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	8,845.1				7,991.8				8,845.1	7,991.8
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS	1,051.1				1,135.4				1,051.1	1,135.4
TOTAL ASSETS	10,589.1				9,603.7				10,589.1	9,603.7
Current Liabilities
Accounts Payable	256.8				276.5				256.8	276.5
Affiliated Companies	35.6				30.3				35.6	30.3
Accrued Taxes	84.9				75.5				84.9	75.5
TOTAL CURRENT LIABILITIES	1,027.2				1,259.5				1,027.2	1,259.5
Liabilities, Noncurrent
Deferred Income Taxes	965.4				913.1				965.4	913.1
Regulatory Liabilities and Deferred Investment Tax Credits	1,316.9				1,344.3				1,316.9	1,344.3
TOTAL NONCURRENT LIABILITIES	6,600.8				5,763.7				6,600.8	5,763.7
TOTAL LIABILITIES	7,628				7,023.2				7,628	7,023.2
Equity [Abstract]
Retained Earnings	1,516				1,337.7				1,516	1,337.7
TOTAL LIABILITIES AND EQUITY	10,589.1				9,603.7				10,589.1	9,603.7
Operating Activites
NET INCOME (LOSS)	(13.7)	77	80.6	34.4	60.2	57.8	46.5	46.8	178.3	211.3	310.5
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization									622.3	499.6	450.1
Deferred Income Taxes									(23.5)	(16.5)	63.3
Allowance for Equity Funds Used During Construction									(15.2)	(20)	(6.8)
Change in Other Noncurrent Assets									(34.7)	(35.4)	(49.4)
Increase (Decrease) in Other Noncurrent Liabilities									11.3	44.9	8.8
Accounts Receivable, Net									3.5	(2.9)	(23.5)
Accounts Payable									7.5	(20.3)	30.8
Accrued Taxes, Net									(11.8)	(5.6)	(31.3)
Net Cash Flows from (Used for) Operating Activities									823.4	651.9	632.7
Investing Activities
Net Cash Flows from (Used for) Investing Activities									(1,472.2)	(1,289.7)	(1,075.3)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from (Used for) Financing Activities									646.8	640.4	452.9
Cash and Cash Equivalents at Beginning of Period				3.1					3.1
Cash and Cash Equivalents at End of Period	3.1				3.1				3.1	3.1
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt									1,070.4	494	749.6
Repayments of Long-term Debt									401.8	266.1	323.1
Net Income (Loss)	(13.7)	77	80.6	34.4	60.2	57.8	46.5	46.8	178.3	211.3	310.5
Retained Earnings	$ 1,516				1,337.7				$ 1,516	1,337.7
AEP Texas Inc. [Member] | Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation	30.00%								30.00%
AEP Texas Inc. [Member] | Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation	54.00%								54.00%
AEP Texas Inc. [Member] | Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation	15.00%								15.00%
AEP Texas Inc. [Member] | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation	1.00%								1.00%
AEP Texas Inc. [Member] | Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation	48.00%								48.00%
AEP Texas Inc. [Member] | Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation	50.00%								50.00%
AEP Texas Inc. [Member] | Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation	2.00%								2.00%
AEP Texas Inc. [Member] | Pension and Other Postretirement Benefit Plans [Member]
Securities Loaned	$ 246				241				$ 246	241
AEP Transmission Co [Member]
Materials and Supplies	13.8				19				13.8	19
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period				0				0	0	0	0
Supplemental Income Statement Elements
Depreciation and Amortization of Property, Plant and Equipment									176	133.9	95.7
Amortization of Certain Securitized Assets									0	0	0
Amortization of Regulatory Assets and Liabilities									0	0	0
Utilities Operating Expense, Depreciation and Amortization									176	133.9	95.7
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts									90.6	80.2	62.4
Income Taxes Paid, Net									1.5	(30.7)	(107.3)
Construction in Progress Expenditures Incurred but Not yet Paid									472.7	345	485
Noncash Investing and Financing Activities:
Lease Obligation Incurred									0	0	0.2
Construction Expenditures Included in Current Liabilities as of December 31,									$ 472.7	$ 345	$ 485
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk									10.00%	10.00%	10.00%
Revenues
TOTAL REVENUES	251.3	259.7	266.9	243.5	189.9	194.4	200.1	191.7	$ 1,021.4	$ 776.1	$ 706.9
Expenses
Depreciation and Amortization									176	133.9	95.7
TOTAL EXPENSES									454.2	366	274
OPERATING INCOME (LOSS)	122.3	142.3	161	141.6	91.5	97	110.5	111.1	567.2	410.1	432.9
Other Income (Expense)
Allowance for Equity Funds Used During Construction									84.3	70.6	49
Interest Expense									(97.4)	(83.2)	(70.2)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)									557.1	400	412.9
Income Tax Expense (Benefit)									117.4	84.1	142.2
NET INCOME (LOSS)	91.8	107.6	136	104.3	71.7	78.1	82	84.1	439.7	315.9	270.7
Accounts Receivable:
Customers	19				11.8				19	11.8
Total Accounts Receivable	85.1				72.8				85.1	72.8
Accrued Tax Benefits	9.3				33.4				9.3	33.4
TOTAL CURRENT ASSETS	197.4				225.5				197.4	225.5
Property, Plant and Equipment
Transmission	8,137.9				6,515.8				8,137.9	6,515.8
Other Property, Plant and Equipment	269.6				174				269.6	174
Construction Work in Progress	1,485.7				1,578.3				1,485.7	1,578.3
Total Property, Plant and Equipment	9,893.2				8,268.1				9,893.2	8,268.1
Accumulated Depreciation and Amortization	402.3				271.9				402.3	271.9
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	9,490.9				7,996.2				9,490.9	7,996.2
Other Noncurrent Assets
Deferred Property Taxes	193.5				157.9				193.5	157.9
TOTAL OTHER NONCURRENT ASSETS	202.5				172.4				202.5	172.4
TOTAL ASSETS	9,890.8				8,394.1				9,890.8	8,394.1	7,082.1
Current Liabilities
Accounts Payable	493.4				347.2				493.4	347.2
Affiliated Companies	71.2				56				71.2	56
Accrued Taxes	355.6				288.9				355.6	288.9
TOTAL CURRENT LIABILITIES	1,093.1				842.2				1,093.1	842.2
Liabilities, Noncurrent
Deferred Income Taxes	817.8				704.4				817.8	704.4
Regulatory Liabilities and Deferred Investment Tax Credits	540.9				521.3				540.9	521.3
TOTAL NONCURRENT LIABILITIES	4,788.2				3,982.1				4,788.2	3,982.1
TOTAL LIABILITIES	5,881.3				4,824.3				5,881.3	4,824.3
Equity [Abstract]
Retained Earnings	1,528.9				1,089.2				1,528.9	1,089.2
TOTAL MEMBER'S EQUITY	4,009.5				3,569.8				4,009.5	3,569.8	2,589.9	1,957.6
TOTAL LIABILITIES AND EQUITY	9,890.8				8,394.1				9,890.8	8,394.1
Operating Activites
NET INCOME (LOSS)	91.8	107.6	136	104.3	71.7	78.1	82	84.1	439.7	315.9	270.7
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization									176	133.9	95.7
Deferred Income Taxes									91.3	98.9	271.5
Allowance for Equity Funds Used During Construction									(84.3)	(70.6)	(49)
Amortization of Deferred Property Taxes									(35.6)	(32.9)	(22.8)
Change in Other Noncurrent Assets									9.6	14.6	11
Increase (Decrease) in Other Noncurrent Liabilities									(8.1)	17.4	27.5
Accounts Receivable, Net									(5.4)	36.7	(30.4)
Accounts Payable									37.6	(7.5)	23
Accrued Taxes, Net									90.8	73.4	16.3
Net Cash Flows from (Used for) Operating Activities									708.6	548.6	604.8
Investing Activities
Net Cash Flows from (Used for) Investing Activities									(1,403.2)	(1,513.3)	(1,595.6)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from (Used for) Financing Activities									694.6	964.7	990.8
Net Increase (Decrease) in Cash and Cash Equivalents									0	0	0
Cash and Cash Equivalents at Beginning of Period				0				0	0	0	0
Cash and Cash Equivalents at End of Period	0				0				0	0	0
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt									688	321	617.6
Repayments of Long-term Debt									85	50	0
Net Income (Loss)	91.8	107.6	136	104.3	71.7	78.1	82	84.1	439.7	315.9	270.7
Retained Earnings	1,528.9				1,089.2				1,528.9	1,089.2
Appalachian Power Co [Member]
Materials and Supplies	105.2				100.1				105.2	100.1
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period				4.2					4.2
Supplemental Income Statement Elements
Depreciation and Amortization of Property, Plant and Equipment									466.5	428.1	407.6
Amortization of Certain Securitized Assets									0	0	0
Amortization of Regulatory Assets and Liabilities									0.3	0.3	0.3
Utilities Operating Expense, Depreciation and Amortization									466.8	428.4	407.9
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts									190.7	182	183.6
Income Taxes Paid, Net									63	(13)	31.2
Construction in Progress Expenditures Incurred but Not yet Paid									149.7	134.4	126.3
Noncash Investing and Financing Activities:
Lease Obligation Incurred									8.8	5.5	3.5
Construction Expenditures Included in Current Liabilities as of December 31,									149.7	134.4	126.3
Restricted Cash	23.5				25.6				23.5	25.6
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	26.8				29.8				$ 26.8	$ 29.8	$ 19.2	18.5
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk									10.00%	10.00%	10.00%
Revenues
TOTAL REVENUES	720.6	755.5	655.8	792.8	718.1	762	667	820.4	$ 2,924.7	$ 2,967.5	$ 2,934.2
Expenses
Depreciation and Amortization									466.8	428.4	407.9
TOTAL EXPENSES									2,527.4	2,484	2,243.9
OPERATING INCOME (LOSS)	25.7	142.6	76.9	152.1	108.1	49.8	132.6	193	397.3	483.5	690.3
Other Income (Expense)
Allowance for Equity Funds Used During Construction									16.6	13.2	9.2
Interest Expense									(205)	(194.8)	(190.9)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)									228.3	322.9	516.6
Income Tax Expense (Benefit)									(78)	(44.9)	185.3
NET INCOME (LOSS)	12.8	104.3	55.5	133.7	77.8	87.1	77.4	125.5	306.3	367.8	331.3
Accounts Receivable:
Customers	129				146.5				129	146.5
Total Accounts Receivable	250.9				283.4				250.9	283.4
TOTAL CURRENT ASSETS	700.6				698.7				700.6	698.7
Property, Plant and Equipment
Transmission	3,584.1				3,317.7				3,584.1	3,317.7
Other Property, Plant and Equipment	571.3				485.8				571.3	485.8
Construction Work in Progress	593.4				490.2				593.4	490.2
Total Property, Plant and Equipment	15,514.2				14,792.7				15,514.2	14,792.7
Accumulated Depreciation and Amortization	4,432.3				4,124.4				4,432.3	4,124.4
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	11,081.9				10,668.3				11,081.9	10,668.3
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS	985.8				923.5				985.8	923.5
TOTAL ASSETS	12,768.3				12,290.5				12,768.3	12,290.5
Current Liabilities
Accounts Payable	307.8				263.8				307.8	263.8
Affiliated Companies	92.5				84				92.5	84
Accrued Taxes	99.6				89.3				99.6	89.3
TOTAL CURRENT LIABILITIES	1,226				1,354				1,226	1,354
Liabilities, Noncurrent
Deferred Income Taxes	1,680.8				1,625.8				1,680.8	1,625.8
Regulatory Liabilities and Deferred Investment Tax Credits	1,268.7				1,449.7				1,268.7	1,449.7
TOTAL NONCURRENT LIABILITIES	7,369.9				6,930.4				7,369.9	6,930.4
TOTAL LIABILITIES	8,595.9				8,284.4				8,595.9	8,284.4
Equity [Abstract]
Retained Earnings	2,078.3				1,922				2,078.3	1,922
TOTAL LIABILITIES AND EQUITY	12,768.3				12,290.5				12,768.3	12,290.5
Operating Activites
NET INCOME (LOSS)	12.8	104.3	55.5	133.7	77.8	87.1	77.4	125.5	306.3	367.8	331.3
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization									466.8	428.4	407.9
Deferred Income Taxes									(126.2)	(16.8)	171.5
Allowance for Equity Funds Used During Construction									(16.6)	(13.2)	(9.2)
Change in Other Noncurrent Assets									(38.2)	58.1	11.4
Increase (Decrease) in Other Noncurrent Liabilities									(40.3)	(4.8)	11.9
Accounts Receivable, Net									35.7	33.6	(28)
Accounts Payable									37.7	(13.3)	37.5
Accrued Taxes, Net									(10.2)	(13.2)	(12.7)
Net Cash Flows from (Used for) Operating Activities									661.4	846.6	880
Investing Activities
Net Cash Flows from (Used for) Investing Activities									(837.4)	(769.4)	(802.3)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from (Used for) Financing Activities									173	(66.6)	(77)
Cash and Cash Equivalents at Beginning of Period				4.2					4.2
Cash and Cash Equivalents at End of Period	3.3				4.2				3.3	4.2
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt									478.2	203.2	320.9
Repayments of Long-term Debt									180.5	124	377.9
Net Income (Loss)	12.8	104.3	55.5	133.7	77.8	87.1	77.4	125.5	306.3	367.8	331.3
Retained Earnings	$ 2,078.3				1,922				$ 2,078.3	1,922
Appalachian Power Co [Member] | Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation	30.00%								30.00%
Appalachian Power Co [Member] | Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation	54.00%								54.00%
Appalachian Power Co [Member] | Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation	15.00%								15.00%
Appalachian Power Co [Member] | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation	1.00%								1.00%
Appalachian Power Co [Member] | Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation	48.00%								48.00%
Appalachian Power Co [Member] | Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation	50.00%								50.00%
Appalachian Power Co [Member] | Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation	2.00%								2.00%
Appalachian Power Co [Member] | Pension and Other Postretirement Benefit Plans [Member]
Securities Loaned	$ 246				241				$ 246	241
Indiana Michigan Power Co [Member]
Materials and Supplies	171.3				167.3				171.3	167.3
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period				2.4				1.3	2.4	1.3	1.2
AEP Consolidated Revenues - Other Revenues:
Ohio Valley Electric Corporation - Barging and Other Transportation Services (43.47% Owned)									63.4	63.4	62.6
Supplemental Income Statement Elements
Depreciation and Amortization of Property, Plant and Equipment									330.6	278.9	203.1
Amortization of Certain Securitized Assets									0	0	0
Amortization of Regulatory Assets and Liabilities									20	14.2	7.8
Utilities Operating Expense, Depreciation and Amortization									350.6	293.1	210.9
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts									111.9	116.9	94.8
Income Taxes Paid, Net									3.4	32.6	(89.9)
Construction in Progress Expenditures Incurred but Not yet Paid									86	93	88.5
Noncash Investing and Financing Activities:
Lease Obligation Incurred									11.9	5.8	7.1
Construction Expenditures Included in Current Liabilities as of December 31,									86	93	88.5
Acquisition of Nuclear Fuel Included in Current Liabilities as of December 31,									0.1	4	0
Expected Reimbursement For Spent Nuclear Fuel Dry Cask Storage									$ 0.3	$ 2.2	$ 2.6
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk									10.00%	10.00%	10.00%
Revenues
TOTAL REVENUES	538.2	611.1	543.1	614.3	574.5	629.7	589.7	576.8	$ 2,306.7	$ 2,370.7	$ 2,121.2
Expenses
Depreciation and Amortization									350.6	293.1	210.9
TOTAL EXPENSES									1,965.9	1,993.5	1,774
OPERATING INCOME (LOSS)	40.6	107.3	77.9	115	52.2	110.2	117.4	97.4	340.8	377.2	347.2
Other Income (Expense)
Allowance for Equity Funds Used During Construction									19.4	11.9	11.1
Interest Expense									(117.9)	(124.1)	(110.8)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)									258.8	290.4	268.1
Income Tax Expense (Benefit)									(10.6)	29.1	81.4
NET INCOME (LOSS)	21.4	88.8	60.3	98.9	29.7	72.7	94.7	64.2	269.4	261.3	186.7
Accounts Receivable:
Customers	53.6				63.1				53.6	63.1
Total Accounts Receivable	109.5				143				109.5	143
Accrued Tax Benefits	0				26.6				0	26.6
TOTAL CURRENT ASSETS	403				430.4				403	430.4
Property, Plant and Equipment
Transmission	1,641.8				1,576.8				1,641.8	1,576.8
Other Property, Plant and Equipment	632.6				583.8				632.6	583.8
Construction Work in Progress	382.3				465.3				382.3	465.3
Total Property, Plant and Equipment	10,194				9,762.8				10,194	9,762.8
Accumulated Depreciation and Amortization	3,294.3				3,151.6				3,294.3	3,151.6
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	6,899.7				6,611.2				6,899.7	6,611.2
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS	3,934.7				3,181				3,934.7	3,181
TOTAL ASSETS	11,237.4				10,222.6				11,237.4	10,222.6
Current Liabilities
Accounts Payable	169.4				174.7				169.4	174.7
Affiliated Companies	68.4				70.2				68.4	70.2
Accrued Taxes	112.4				90.7				112.4	90.7
TOTAL CURRENT LIABILITIES	883.4				698.1				883.4	698.1
Liabilities, Noncurrent
Deferred Income Taxes	979.7				948				979.7	948
Regulatory Liabilities and Deferred Investment Tax Credits	1,891.4				1,574.5				1,891.4	1,574.5
TOTAL NONCURRENT LIABILITIES	7,809.6				7,171.7				7,809.6	7,171.7
TOTAL LIABILITIES	8,693				7,869.8				8,693	7,869.8
Equity [Abstract]
Retained Earnings	1,518.5				1,329.1				1,518.5	1,329.1
TOTAL LIABILITIES AND EQUITY	11,237.4				10,222.6				11,237.4	10,222.6
Operating Activites
NET INCOME (LOSS)	21.4	88.8	60.3	98.9	29.7	72.7	94.7	64.2	269.4	261.3	186.7
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization									350.6	293.1	210.9
Deferred Income Taxes									(52.7)	(42.9)	200.7
Allowance for Equity Funds Used During Construction									(19.4)	(11.9)	(11.1)
Change in Other Noncurrent Assets									8.3	(36.5)	(101.1)
Increase (Decrease) in Other Noncurrent Liabilities									33.7	72.1	37.4
Accounts Receivable, Net									35.4	4.8	(1.1)
Accounts Payable									3.6	(14.1)	17.6
Accrued Taxes, Net									48.3	41.2	(16.6)
Net Cash Flows from (Used for) Operating Activities									685.2	725.7	661.3
Investing Activities
Net Cash Flows from (Used for) Investing Activities									(720.1)	(654.8)	(790.9)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from (Used for) Financing Activities									34.5	(69.8)	129.7
Net Increase (Decrease) in Cash and Cash Equivalents									(0.4)	1.1	0.1
Cash and Cash Equivalents at Beginning of Period				2.4				1.3	2.4	1.3	1.2
Cash and Cash Equivalents at End of Period	2				2.4				2	2.4	1.3
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt									123.3	1,168.1	530.1
Repayments of Long-term Debt									117.1	884.9	260.7
Net Income (Loss)	21.4	88.8	60.3	98.9	29.7	72.7	94.7	64.2	269.4	261.3	186.7
Retained Earnings	$ 1,518.5				1,329.1				$ 1,518.5	1,329.1
Indiana Michigan Power Co [Member] | Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation	30.00%								30.00%
Indiana Michigan Power Co [Member] | Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation	54.00%								54.00%
Indiana Michigan Power Co [Member] | Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation	15.00%								15.00%
Indiana Michigan Power Co [Member] | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation	1.00%								1.00%
Indiana Michigan Power Co [Member] | Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation	48.00%								48.00%
Indiana Michigan Power Co [Member] | Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation	50.00%								50.00%
Indiana Michigan Power Co [Member] | Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation	2.00%								2.00%
Indiana Michigan Power Co [Member] | Pension and Other Postretirement Benefit Plans [Member]
Securities Loaned	$ 246				241				$ 246	241
Ohio Power Co [Member]
Materials and Supplies	52.3				42.9				52.3	42.9
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period				4.9					4.9
Supplemental Income Statement Elements
Depreciation and Amortization of Property, Plant and Equipment									229.4	232.6	200.9
Amortization of Certain Securitized Assets									22	47.9	44.4
Amortization of Regulatory Assets and Liabilities									(10.5)	(20.8)	(19.4)
Utilities Operating Expense, Depreciation and Amortization									240.9	259.7	225.9
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts									100.6	97.1	100
Income Taxes Paid, Net									7.3	51.3	48.5
Construction in Progress Expenditures Incurred but Not yet Paid									125.9	98.2	87.8
Noncash Investing and Financing Activities:
Lease Obligation Incurred									11.3	4.4	4.5
Construction Expenditures Included in Current Liabilities as of December 31,									125.9	98.2	87.8
Restricted Cash	0				27.6				0	27.6
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	3.7				32.5				$ 3.7	$ 32.5	$ 29.7	$ 30.3
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk									10.00%	10.00%	10.00%
Revenues
TOTAL REVENUES	643.6	710.6	606.6	836.8	745.4	778.3	748.8	790.9	$ 2,797.6	$ 3,063.4	$ 2,883.9
Expenses
Depreciation and Amortization									240.9	259.7	225.9
TOTAL EXPENSES									2,396.4	2,643.6	2,318.2
OPERATING INCOME (LOSS)	63	98.6	77.1	162.5	118.2	79.9	104.4	117.3	401.2	419.8	565.7
Other Income (Expense)
Allowance for Equity Funds Used During Construction									18.2	9.8	6.4
Interest Expense									(106.2)	(100.7)	(101.9)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)									332	349.5	483.2
Income Tax Expense (Benefit)									34.9	24	159.3
NET INCOME (LOSS)	49.4	69.1	50.6	128	88.4	88.7	68.8	79.6	297.1	325.5	323.9
Accounts Receivable:
Customers	53				111.1				53	111.1
Total Accounts Receivable	132.4				202.6				132.4	202.6
TOTAL CURRENT ASSETS	238.5				319.6				238.5	319.6
Property, Plant and Equipment
Transmission	2,686.3				2,544.3				2,686.3	2,544.3
Other Property, Plant and Equipment	765.8				574.8				765.8	574.8
Construction Work in Progress	394.4				432.1				394.4	432.1
Total Property, Plant and Equipment	9,170				8,493.5				9,170	8,493.5
Accumulated Depreciation and Amortization	2,263				2,218.6				2,263	2,218.6
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	6,907				6,274.9				6,907	6,274.9
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS	898.1				841.4				898.1	841.4
TOTAL ASSETS	8,043.6				7,435.9				8,043.6	7,435.9
Current Liabilities
Accounts Payable	233.7				211.9				233.7	211.9
Affiliated Companies	103.6				102.9				103.6	102.9
Accrued Taxes	587.9				537.8				587.9	537.8
TOTAL CURRENT LIABILITIES	1,297.9				1,347.7				1,297.9	1,347.7
Liabilities, Noncurrent
Deferred Income Taxes	849.4				763.3				849.4	763.3
Regulatory Liabilities and Deferred Investment Tax Credits	1,090.9				1,221.2				1,090.9	1,221.2
TOTAL NONCURRENT LIABILITIES	4,237.2				3,790.8				4,237.2	3,790.8
TOTAL LIABILITIES	5,535.1				5,138.5				5,535.1	5,138.5
Equity [Abstract]
Retained Earnings	1,348.5				1,136.4				1,348.5	1,136.4
TOTAL LIABILITIES AND EQUITY	8,043.6				7,435.9				8,043.6	7,435.9
Operating Activites
NET INCOME (LOSS)	49.4	69.1	50.6	128	88.4	88.7	68.8	79.6	297.1	325.5	323.9
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization									240.9	259.7	225.9
Deferred Income Taxes									43.8	(36.2)	147.9
Allowance for Equity Funds Used During Construction									(18.2)	(9.8)	(6.4)
Amortization of Deferred Property Taxes									(33.7)	(12.5)	(17.9)
Change in Other Noncurrent Assets									(35.3)	(11.5)	(54.7)
Increase (Decrease) in Other Noncurrent Liabilities									(93.2)	53.8	15.8
Accounts Receivable, Net									75	43.1	(30.1)
Accounts Payable									0.4	(13.8)	11.6
Accrued Taxes, Net									38.7	26.8	(9.4)
Net Cash Flows from (Used for) Operating Activities									421.2	1,028.7	622.2
Investing Activities
Net Cash Flows from (Used for) Investing Activities									(744.1)	(707.5)	(530.9)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from (Used for) Financing Activities									294.1	(318.4)	(91.9)
Cash and Cash Equivalents at Beginning of Period				4.9					4.9
Cash and Cash Equivalents at End of Period	3.7				4.9				3.7	4.9
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt									444.3	392.8	0
Repayments of Long-term Debt									80.3	397.1	46.4
Net Income (Loss)	49.4	69.1	50.6	128	88.4	88.7	68.8	79.6	297.1	325.5	323.9
Retained Earnings	$ 1,348.5				1,136.4				$ 1,348.5	1,136.4
Ohio Power Co [Member] | Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation	30.00%								30.00%
Ohio Power Co [Member] | Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation	54.00%								54.00%
Ohio Power Co [Member] | Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation	15.00%								15.00%
Ohio Power Co [Member] | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation	1.00%								1.00%
Ohio Power Co [Member] | Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation	48.00%								48.00%
Ohio Power Co [Member] | Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation	50.00%								50.00%
Ohio Power Co [Member] | Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation	2.00%								2.00%
Ohio Power Co [Member] | Pension and Other Postretirement Benefit Plans [Member]
Securities Loaned	$ 246				241				$ 246	241
Public Service Co Of Oklahoma [Member]
Materials and Supplies	46.8				44.8				46.8	44.8
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period				2				1.6	2	1.6	1.5
Supplemental Income Statement Elements
Depreciation and Amortization of Property, Plant and Equipment									162.5	155.5	131.4
Amortization of Certain Securitized Assets									0	0	0
Amortization of Regulatory Assets and Liabilities									7	8.5	(1)
Utilities Operating Expense, Depreciation and Amortization									169.5	164	130.4
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts									61.1	62	61.5
Income Taxes Paid, Net									22.4	17.9	(72.6)
Construction in Progress Expenditures Incurred but Not yet Paid									46	33.2	23.1
Noncash Investing and Financing Activities:
Construction Expenditures Included in Current Liabilities as of December 31,									$ 46	$ 33.2	$ 23.1
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk									10.00%	10.00%	10.00%
Revenues
TOTAL REVENUES	307.9	493	348.1	332.8	330.8	481.4	398.3	336.8	$ 1,481.8	$ 1,547.3	$ 1,427.2
Expenses
Depreciation and Amortization									169.5	164	130.4
TOTAL EXPENSES									1,282.5	1,404.8	1,255.7
OPERATING INCOME (LOSS)	1.8	120	56.6	20.9	2.9	78.5	57.2	3.9	199.3	142.5	171.5
Other Income (Expense)
Allowance for Equity Funds Used During Construction									2.7	0.4	0.5
Interest Expense									(66.5)	(63.5)	(53.4)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)									145.1	88.2	122.1
Income Tax Expense (Benefit)									7.5	5	50.1
NET INCOME (LOSS)	(10.8)	100.3	41.9	6.2	(6.6)	60.4	36.6	(7.2)	137.6	83.2	72
Accounts Receivable:
Customers	28.9				32.5				28.9	32.5
Total Accounts Receivable	49.8				64.3				49.8	64.3
Accrued Tax Benefits	11.3				14.7				11.3	14.7
TOTAL CURRENT ASSETS	188.2				157.9				188.2	157.9
Property, Plant and Equipment
Transmission	948.5				892.3				948.5	892.3
Other Property, Plant and Equipment	342.1				303.5				342.1	303.5
Construction Work in Progress	133.4				94				133.4	94
Total Property, Plant and Equipment	5,683.4				5,439.6				5,683.4	5,439.6
Accumulated Depreciation and Amortization	1,580.1				1,472.9				1,580.1	1,472.9
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	4,103.3				3,966.7				4,103.3	3,966.7
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS	460				407.8				460	407.8
TOTAL ASSETS	4,751.5				4,532.4				4,751.5	4,532.4
Current Liabilities
Accounts Payable	134.3				126.9				134.3	126.9
Affiliated Companies	59.3				47.1				59.3	47.1
Accrued Taxes	22.9				22.4				22.9	22.4
TOTAL CURRENT LIABILITIES	445.8				821.6				445.8	821.6
Liabilities, Noncurrent
Deferred Income Taxes	628.3				607.8				628.3	607.8
Regulatory Liabilities and Deferred Investment Tax Credits	837.2				864.7				837.2	864.7
TOTAL NONCURRENT LIABILITIES	2,932.4				2,462.8				2,932.4	2,462.8
TOTAL LIABILITIES	3,378.2				3,284.4				3,378.2	3,284.4
Equity [Abstract]
Retained Earnings	851				724.7				851	724.7
TOTAL LIABILITIES AND EQUITY	4,751.5				4,532.4				4,751.5	4,532.4
Operating Activites
NET INCOME (LOSS)	(10.8)	100.3	41.9	6.2	(6.6)	60.4	36.6	(7.2)	137.6	83.2	72
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization									169.5	164	130.4
Deferred Income Taxes									(18.2)	(31.1)	124.7
Allowance for Equity Funds Used During Construction									(2.7)	(0.4)	(0.5)
Change in Other Noncurrent Assets									5.7	0	(27.2)
Increase (Decrease) in Other Noncurrent Liabilities									1.8	17.6	4.5
Accounts Receivable, Net									15.4	5.1	(10.9)
Accounts Payable									7	17.7	(10.7)
Accrued Taxes, Net									3.9	13.2	0.8
Net Cash Flows from (Used for) Operating Activities									350.3	330.5	238.1
Investing Activities
Net Cash Flows from (Used for) Investing Activities									(328.1)	(233)	(261.5)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from (Used for) Financing Activities									(22.7)	(97.1)	23.5
Net Increase (Decrease) in Cash and Cash Equivalents									(0.5)	0.4	0.1
Cash and Cash Equivalents at Beginning of Period				2				1.6	2	1.6	1.5
Cash and Cash Equivalents at End of Period	1.5				2				1.5	2	1.6
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt									349.5	0	0
Repayments of Long-term Debt									250.5	0.5	0.5
Net Income (Loss)	(10.8)	100.3	41.9	6.2	(6.6)	60.4	36.6	(7.2)	137.6	83.2	72
Retained Earnings	$ 851				724.7				$ 851	724.7
Public Service Co Of Oklahoma [Member] | Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation	30.00%								30.00%
Public Service Co Of Oklahoma [Member] | Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation	54.00%								54.00%
Public Service Co Of Oklahoma [Member] | Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation	15.00%								15.00%
Public Service Co Of Oklahoma [Member] | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation	1.00%								1.00%
Public Service Co Of Oklahoma [Member] | Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation	48.00%								48.00%
Public Service Co Of Oklahoma [Member] | Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation	50.00%								50.00%
Public Service Co Of Oklahoma [Member] | Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation	2.00%								2.00%
Public Service Co Of Oklahoma [Member] | Pension and Other Postretirement Benefit Plans [Member]
Securities Loaned	$ 246				241				$ 246	241
Southwestern Electric Power Co [Member]
Materials and Supplies	94				90				94	90
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period				24.5				1.6	24.5	1.6	10.3
Supplemental Income Statement Elements
Depreciation and Amortization of Property, Plant and Equipment									247.9	237	217.2
Amortization of Certain Securitized Assets									0	0	0
Amortization of Regulatory Assets and Liabilities									1.2	2.5	0.2
Utilities Operating Expense, Depreciation and Amortization									249.1	239.5	217.4
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts									111.1	125.7	124.4
Income Taxes Paid, Net									8.6	18.8	(75.3)
Construction in Progress Expenditures Incurred but Not yet Paid									69.1	42	71.2
Noncash Investing and Financing Activities:
Construction Expenditures Included in Current Liabilities as of December 31,									$ 69.1	$ 42	$ 71.2
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk									10.00%	10.00%	10.00%
Amounts Attributable to AEP Common Shareholders
Net Income (Loss) Attributable to Noncontrolling Interests									$ 3.6	$ 5	$ 12.8
Net Income (Loss)	14.1	110.5	6.2	27.8	9.6	88.2	37.6	11.8	158.6	147.2	124.7
Revenues
TOTAL REVENUES	408.8	545.5	375.5	421.1	410.1	535.3	457.1	419.4	1,750.9	1,821.9	1,779.9
Expenses
Depreciation and Amortization									249.1	239.5	217.4
TOTAL EXPENSES									1,495.2	1,544.2	1,475.9
OPERATING INCOME (LOSS)	33.9	134.7	33	54.1	38.5	127.1	70.5	41.6	255.7	277.7	304
Other Income (Expense)
Allowance for Equity Funds Used During Construction									6.8	6	2.4
Interest Expense									(119.1)	(127.9)	(123.4)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)									154.5	169.9	189.4
Income Tax Expense (Benefit)									(4.7)	20.4	48.1
NET INCOME (LOSS)	14.6	111.3	7.3	29	10.5	89.6	38.7	13.4	162.2	152.2	137.5
Accounts Receivable:
Customers	29				24.5				29	24.5
Total Accounts Receivable	75.3				72.8				75.3	72.8
TOTAL CURRENT ASSETS	354.1				414.5				354.1	414.5
Property, Plant and Equipment
Transmission	2,056.5				1,866.9				2,056.5	1,866.9
Other Property, Plant and Equipment	733.4				762.7				733.4	762.7
Construction Work in Progress	216.9				199.3				216.9	199.3
Total Property, Plant and Equipment	9,968.9				9,680.1				9,968.9	9,680.1
Accumulated Depreciation and Amortization	2,873.7				2,808.3				2,873.7	2,808.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	7,095.2				6,871.8				7,095.2	6,871.8
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS	382.9				342				382.9	342
TOTAL ASSETS	7,832.2				7,628.3				7,832.2	7,628.3
Current Liabilities
Accounts Payable	138				129.1				138	129.1
Affiliated Companies	53.6				64.2				53.6	64.2
Accrued Taxes	41.8				42.8				41.8	42.8
TOTAL CURRENT LIABILITIES	674.7				512.9				674.7	512.9
Liabilities, Noncurrent
Deferred Income Taxes	940.9				902.8				940.9	902.8
Regulatory Liabilities and Deferred Investment Tax Credits	892.3				923				892.3	923
TOTAL NONCURRENT LIABILITIES	4,716.4				4,799.8				4,716.4	4,799.8
TOTAL LIABILITIES	5,391.1				5,312.7				5,391.1	5,312.7
Equity [Abstract]
Retained Earnings	1,629.5				1,508.4				1,629.5	1,508.4
TOTAL LIABILITIES AND EQUITY	7,832.2				7,628.3				7,832.2	7,628.3
Operating Activites
NET INCOME (LOSS)	14.6	111.3	7.3	29	10.5	89.6	38.7	13.4	162.2	152.2	137.5
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization									249.1	239.5	217.4
Deferred Income Taxes									(11)	1.2	80.5
Allowance for Equity Funds Used During Construction									(6.8)	(6)	(2.4)
Change in Other Noncurrent Assets									6.2	(18.8)	(9.2)
Increase (Decrease) in Other Noncurrent Liabilities									2.7	42.8	4.7
Accounts Receivable, Net									0	53.5	(32.9)
Accounts Payable									(28.4)	0.9	10.5
Accrued Taxes, Net									(3.2)	2.3	45.7
Net Cash Flows from (Used for) Operating Activities									339.8	504.8	444.7
Investing Activities
Net Cash Flows from (Used for) Investing Activities									(330.2)	(528.9)	(220.6)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from (Used for) Financing Activities									(32.5)	47	(232.8)
Net Increase (Decrease) in Cash and Cash Equivalents									(22.9)	22.9	(8.7)
Cash and Cash Equivalents at Beginning of Period				24.5				1.6	24.5	1.6	10.3
Cash and Cash Equivalents at End of Period	1.6				24.5				1.6	24.5	1.6
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt									0	1,065.7	114.6
Repayments of Long-term Debt									59.7	794.5	353.7
Income (Loss) from Equity Method Investment									3	2.7	(3.8)
Net Income (Loss)	14.6	$ 111.3	$ 7.3	29	10.5	$ 89.6	$ 38.7	$ 13.4	162.2	152.2	$ 137.5
Retained Earnings	$ 1,629.5				1,508.4				$ 1,629.5	1,508.4
Southwestern Electric Power Co [Member] | Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation	30.00%								30.00%
Southwestern Electric Power Co [Member] | Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation	54.00%								54.00%
Southwestern Electric Power Co [Member] | Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation	15.00%								15.00%
Southwestern Electric Power Co [Member] | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation	1.00%								1.00%
Southwestern Electric Power Co [Member] | Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation	48.00%								48.00%
Southwestern Electric Power Co [Member] | Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation	50.00%								50.00%
Southwestern Electric Power Co [Member] | Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation	2.00%								2.00%
Southwestern Electric Power Co [Member] | Pension and Other Postretirement Benefit Plans [Member]
Securities Loaned	$ 246				241				$ 246	$ 241
Restricted Stock Units and Performance Share Units [Member]
Weighted Average Dilutive Effect of:
Weighted Average Dilutive Effect of Shares									1,600,000	1,000,000	800,000
Dilutive Securities, Effect on Basic Earnings Per Share									$ (0.01)	$ 0	$ (0.01)
Revenues [Member] | AEP Texas Inc. [Member]
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk									48.00%	45.00%	35.00%
Revenues [Member] | AEP Transmission Co [Member]
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk									79.00%	77.00%	80.00%
Accounts Receivable [Member] | AEP Texas Inc. [Member]
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk									43.00%	35.00%	31.00%
Accounts Receivable [Member] | AEP Transmission Co [Member]
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk									78.00%	84.00%	85.00%
Noncontrolling Interest [Member]
Noncash Investing and Financing Activities:
Noncash Contribution of Assets by Noncontrolling Interest									$ 253.4	$ 0	$ 0
Sabine Mining Co [Member]
Materials and Supplies					23					23
Sabine Mining Co [Member] | Southwestern Electric Power Co [Member]
Materials and Supplies	23.1				22.5				23.1	22.5
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period				22					22
Property, Plant and Equipment
Other Property, Plant and Equipment	212.3				276.9				212.3	276.9
Accumulated Depreciation and Amortization	107.5				174.6				107.5	174.6
Net Cash Provided by (Used in) Financing Activities
Cash and Cash Equivalents at Beginning of Period				$ 22					22
Cash and Cash Equivalents at End of Period	$ 0				$ 22				$ 0	$ 22

Comprehensive Income (Details)

Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	$ (120.4)	$ (67.8)	$ (156.3)
Change in Fair Value Recognized in AOCI	(69.7)	6.6	71.2
Commodity
Generation and Marketing Revenues	15,561.4	16,195.7	15,424.9
Interest Rate
Interest Expense	1,072.5	984.4	895
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	53.7	(38.3)	26.4
Income Tax (Expense) Benefit	(12.9)	115.3	969.7
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	42.4	(30.3)	17.3
Net Current Period Other Comprehensive Income (Loss)	(27.3)	(23.7)	88.5
ASU 2018-02 Adoption		(3)
ASU 2016-01 Adoption		0
Ending Balance in AOCI	(147.7)	(120.4)	(67.8)
Securities Available for Sale [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	0	11.9	8.4
Change in Fair Value Recognized in AOCI		0	3.5
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		0	0
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		0	0
Net Current Period Other Comprehensive Income (Loss)		0	3.5
ASU 2018-02 Adoption		0
ASU 2016-01 Adoption		(11.9)
Ending Balance in AOCI		0	11.9
Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	136.3	141.6	140.5
Change in Fair Value Recognized in AOCI	0	0	0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	(7.1)	(6.7)	1.7
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	(5.6)	(5.3)	1.1
Net Current Period Other Comprehensive Income (Loss)	(5.6)	(5.3)	1.1
ASU 2018-02 Adoption		0
ASU 2016-01 Adoption		0
Ending Balance in AOCI	130.7	136.3	141.6
Pension and OPEB [Member] | Changes in Funded Status [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	(221.1)	(179.9)	(266.4)
Change in Fair Value Recognized in AOCI	57.7	(33)	86.5
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	0	0	0
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	0	0	0
Net Current Period Other Comprehensive Income (Loss)	57.7	(33)	86.5
ASU 2018-02 Adoption		(8.2)
ASU 2016-01 Adoption		0
Ending Balance in AOCI	(163.4)	(221.1)	(179.9)
Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)	(27.3)	(23.7)	88.5
ASU 2018-02 Adoption		(17)
ASU 2016-01 Adoption		(11.9)
Commodity [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	(23)	(28.4)	(23.1)
Change in Fair Value Recognized in AOCI	(127.2)	37.3	(20.4)
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	59.3	(32.7)	23.2
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	46.7	(25.8)	15.1
Net Current Period Other Comprehensive Income (Loss)	(80.5)	11.5	(5.3)
ASU 2018-02 Adoption		(6.1)
ASU 2016-01 Adoption		0
Ending Balance in AOCI	(103.5)	(23)	(28.4)
Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	(12.6)	(13)	(15.7)
Change in Fair Value Recognized in AOCI	(0.2)	2.3	1.6
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	1.5	1.1	1.5
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	1.3	0.8	1.1
Net Current Period Other Comprehensive Income (Loss)	1.1	3.1	2.7
ASU 2018-02 Adoption		(2.7)
ASU 2016-01 Adoption		0
Ending Balance in AOCI	(11.5)	(12.6)	(13)
Generation and Marketing Revenues [Member]
Commodity
Generation and Marketing Revenues	1,721.8	1,818.1	1,771.4
Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale	3,165.2	3,427.1	2,965.3
Apple Blossom and Black Oak [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Change in Fair Value Recognized in AOCI	4
AEP Texas Inc. [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	(15.1)	(12.6)	(14.9)
Change in Fair Value Recognized in AOCI	1.1	(1)	1.1
Commodity
Generation and Marketing Revenues	1,551.6	1,493
Interest Rate
Interest Expense	137.2	147.3	142.3
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	1.5	1.6	1.7
Income Tax (Expense) Benefit	(53.6)	20.8	(23.4)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	1.2	1.2	1.2
Net Current Period Other Comprehensive Income (Loss)	2.3	0.2	2.3
ASU 2018-02 Adoption		(0.9)
Ending Balance in AOCI	(12.8)	(15.1)	(12.6)
AEP Texas Inc. [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	4.7	4.5	4.2
Change in Fair Value Recognized in AOCI	0	0	0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	0.2	0.3	0.4
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	0.2	0.2	0.3
Net Current Period Other Comprehensive Income (Loss)	0.2	0.2	0.3
ASU 2018-02 Adoption		0
Ending Balance in AOCI	4.9	4.7	4.5
AEP Texas Inc. [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	(15.4)	(12.6)	(13.7)
Change in Fair Value Recognized in AOCI	1.1	(1)	1.1
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	0	0	0
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	0	0	0
Net Current Period Other Comprehensive Income (Loss)	1.1	(1)	1.1
ASU 2018-02 Adoption		(1.8)
Ending Balance in AOCI	(14.3)	(15.4)	(12.6)
AEP Texas Inc. [Member] | Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)	2.3	0.2	2.3
ASU 2018-02 Adoption		(2.7)
AEP Texas Inc. [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	(4.4)	(4.5)	(5.4)
Change in Fair Value Recognized in AOCI	0	0	0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	1.3	1.3	1.3
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	1	1	0.9
Net Current Period Other Comprehensive Income (Loss)	1	1	0.9
ASU 2018-02 Adoption		(0.9)
Ending Balance in AOCI	(3.4)	(4.4)	(4.5)
Appalachian Power Co [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	(5)	1.3	(8.4)
Change in Fair Value Recognized in AOCI	13.4	(3.3)	11.6
Commodity
Generation and Marketing Revenues	2,911.1	2,993.2
Interest Rate
Interest Expense	205	194.8	190.9
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	(4.3)	(4.1)	(2.9)
Income Tax (Expense) Benefit	(78)	(44.9)	185.3
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	(3.4)	(3.3)	(1.9)
Net Current Period Other Comprehensive Income (Loss)	10	(6.6)	9.7
ASU 2018-02 Adoption		0.4
Ending Balance in AOCI	5	(5)	1.3
Appalachian Power Co [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	11.7	14.8	16
Change in Fair Value Recognized in AOCI	0	0	0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	(3.2)	(3.9)	(1.8)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	(2.5)	(3.1)	(1.2)
Net Current Period Other Comprehensive Income (Loss)	(2.5)	(3.1)	(1.2)
ASU 2018-02 Adoption		0
Ending Balance in AOCI	9.2	11.7	14.8
Appalachian Power Co [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	(18.5)	(15.7)	(27.3)
Change in Fair Value Recognized in AOCI	13.4	(2.6)	11.6
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	0	0	0
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	0	0	0
Net Current Period Other Comprehensive Income (Loss)	13.4	(2.6)	11.6
ASU 2018-02 Adoption		(0.2)
Ending Balance in AOCI	(5.1)	(18.5)	(15.7)
Appalachian Power Co [Member] | Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)	10	(6.6)	9.7
ASU 2018-02 Adoption		0.3
Appalachian Power Co [Member] | Commodity [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	0	0
Change in Fair Value Recognized in AOCI		(0.7)
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		0.9
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		0.7
Net Current Period Other Comprehensive Income (Loss)		0
ASU 2018-02 Adoption		0
Ending Balance in AOCI		0	0
Appalachian Power Co [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	1.8	2.2	2.9
Change in Fair Value Recognized in AOCI	0	0	0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	(1.1)	(1.1)	(1.1)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	(0.9)	(0.9)	(0.7)
Net Current Period Other Comprehensive Income (Loss)	(0.9)	(0.9)	(0.7)
ASU 2018-02 Adoption		0.5
Ending Balance in AOCI	0.9	1.8	2.2
Appalachian Power Co [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale	391	503.5	357.6
Indiana Michigan Power Co [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	(13.8)	(12.1)	(16.2)
Change in Fair Value Recognized in AOCI	0.8	(0.6)	2.8
Commodity
Generation and Marketing Revenues	2,308.1	2,381
Interest Rate
Interest Expense	117.9	124.1	110.8
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	1.8	2	2
Income Tax (Expense) Benefit	(10.6)	29.1	81.4
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	1.4	1.6	1.3
Net Current Period Other Comprehensive Income (Loss)	2.2	1	4.1
ASU 2018-02 Adoption		(2.4)
Ending Balance in AOCI	(11.6)	(13.8)	(12.1)
Indiana Michigan Power Co [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	5.1	5.1	5.1
Change in Fair Value Recognized in AOCI	0	0	0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	(0.2)	0	0
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	(0.2)	0	0
Net Current Period Other Comprehensive Income (Loss)	(0.2)	0	0
ASU 2018-02 Adoption		0
Ending Balance in AOCI	4.9	5.1	5.1
Indiana Michigan Power Co [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	(7.4)	(6.5)	(9.3)
Change in Fair Value Recognized in AOCI	0.8	(0.6)	2.8
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	0	0	0
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	0	0	0
Net Current Period Other Comprehensive Income (Loss)	0.8	(0.6)	2.8
ASU 2018-02 Adoption		(0.3)
Ending Balance in AOCI	(6.6)	(7.4)	(6.5)
Indiana Michigan Power Co [Member] | Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)	2.2	1	4.1
ASU 2018-02 Adoption		(2.7)
Indiana Michigan Power Co [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	(11.5)	(10.7)	(12)
Change in Fair Value Recognized in AOCI	0	0	0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	2	2	2
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	1.6	1.6	1.3
Net Current Period Other Comprehensive Income (Loss)	1.6	1.6	1.3
ASU 2018-02 Adoption		(2.4)
Ending Balance in AOCI	(9.9)	(11.5)	(10.7)
Indiana Michigan Power Co [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale	232.3	221.8	152.2
Ohio Power Co [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	1
Commodity
Generation and Marketing Revenues	2,748.8	3,079.9
Interest Rate
Interest Expense	106.2	100.7	101.9
Pension and OPEB
Income Tax (Expense) Benefit	34.9	24	159.3
Net Current Period Other Comprehensive Income (Loss)	(1)	(1.3)	(1.1)
ASU 2018-02 Adoption		0.4
Ending Balance in AOCI	0	1
Ohio Power Co [Member] | Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)	(1)	(1.3)	(1.1)
ASU 2018-02 Adoption		0.4
Ohio Power Co [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	1	1.9	3
Change in Fair Value Recognized in AOCI	0	0	0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		(1.7)	(1.7)
Income Tax (Expense) Benefit	(1)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		(1.3)	(1.1)
Net Current Period Other Comprehensive Income (Loss)	(1)	(1.3)	(1.1)
ASU 2018-02 Adoption		0.4
Ending Balance in AOCI	0	1	1.9
Ohio Power Co [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale	607.3	684.6	705.9
Public Service Co Of Oklahoma [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	2.1
Commodity
Generation and Marketing Revenues	1,512.8	1,536.4
Interest Rate
Interest Expense	66.5	63.5	53.4
Pension and OPEB
Income Tax (Expense) Benefit	7.5	5	50.1
Net Current Period Other Comprehensive Income (Loss)	(1)	(1)	(0.8)
ASU 2018-02 Adoption		0.5
Ending Balance in AOCI	1.1	2.1
Public Service Co Of Oklahoma [Member] | Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)	(1)	(1)	(0.8)
ASU 2018-02 Adoption		0.5
Public Service Co Of Oklahoma [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	2.1	2.6	3.4
Change in Fair Value Recognized in AOCI	0	0	0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	(1.3)	(1.3)	(1.3)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	(1)	(1)	(0.8)
Net Current Period Other Comprehensive Income (Loss)	(1)	(1)	(0.8)
ASU 2018-02 Adoption		0.5
Ending Balance in AOCI	1.1	2.1	2.6
Public Service Co Of Oklahoma [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale	458.9	479.9	514.9
Southwestern Electric Power Co [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	(5.4)	(4)	(9.4)
Change in Fair Value Recognized in AOCI	3.7	(0.8)	4.7
Commodity
Generation and Marketing Revenues	1,799.2	1,817
Interest Rate
Interest Expense	119.1	127.9	123.4
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	0.5	0.3	1.1
Income Tax (Expense) Benefit	(4.7)	20.4	48.1
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	0.4	0.3	0.7
Net Current Period Other Comprehensive Income (Loss)	4.1	(0.5)	5.4
ASU 2018-02 Adoption		(1.3)
Ending Balance in AOCI	(1.3)	(5.4)	(4)
Southwestern Electric Power Co [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	(0.2)	1.2	1.9
Change in Fair Value Recognized in AOCI	0	0	0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	(1.4)	(1.8)	(1.1)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	(1.1)	(1.4)	(0.7)
Net Current Period Other Comprehensive Income (Loss)	(1.1)	(1.4)	(0.7)
ASU 2018-02 Adoption		0
Ending Balance in AOCI	(1.3)	(0.2)	1.2
Southwestern Electric Power Co [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	(1.9)	0.8	(3.9)
Change in Fair Value Recognized in AOCI	3.7	(3.1)	4.7
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	0	0	0
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	0	0	0
Net Current Period Other Comprehensive Income (Loss)	3.7	(3.1)	4.7
ASU 2018-02 Adoption		0.4
Ending Balance in AOCI	1.8	(1.9)	0.8
Southwestern Electric Power Co [Member] | Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)	4.1	(0.5)	5.4
ASU 2018-02 Adoption		(0.9)
Southwestern Electric Power Co [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI	(3.3)	(6)	(7.4)
Change in Fair Value Recognized in AOCI	0	2.3	0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit	1.9	2.1	2.2
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit	1.5	1.7	1.4
Net Current Period Other Comprehensive Income (Loss)	1.5	4	1.4
ASU 2018-02 Adoption		(1.3)
Ending Balance in AOCI	(1.8)	(3.3)	(6)
Southwestern Electric Power Co [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale	179.5	177.1	168.7
Reclassifications from Accumulated Other Comprehensive Income [Member]
Interest Rate
Interest Expense	1.5	1.1	1.5
Pension and OPEB
Amortization of Prior Service Cost (Credit)	(19.2)	(19.5)	(19.6)
Amortization of Actuarial (Gains) Losses	12.1	12.8	21.3
Income Tax (Expense) Benefit	11.3	(8)	9.1
Reclassifications from Accumulated Other Comprehensive Income [Member] | Securities Available for Sale [Member]
Interest Rate
Interest Expense		0	0
Pension and OPEB
Amortization of Prior Service Cost (Credit)		0	0
Amortization of Actuarial (Gains) Losses		0	0
Income Tax (Expense) Benefit		0	0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Interest Rate
Interest Expense	0	0	0
Pension and OPEB
Amortization of Prior Service Cost (Credit)	(19.2)	(19.5)	(19.6)
Amortization of Actuarial (Gains) Losses	12.1	12.8	21.3
Income Tax (Expense) Benefit	(1.5)	(1.4)	0.6
Reclassifications from Accumulated Other Comprehensive Income [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Interest Rate
Interest Expense	0	0	0
Pension and OPEB
Amortization of Prior Service Cost (Credit)	0	0	0
Amortization of Actuarial (Gains) Losses	0	0	0
Income Tax (Expense) Benefit	0	0	0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Commodity [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Interest Rate
Interest Expense	0	0	0
Pension and OPEB
Amortization of Prior Service Cost (Credit)	0	0	0
Amortization of Actuarial (Gains) Losses	0	0	0
Income Tax (Expense) Benefit	12.6	(6.9)	8.1
Reclassifications from Accumulated Other Comprehensive Income [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Interest Rate
Interest Expense	1.5	1.1	1.5
Pension and OPEB
Amortization of Prior Service Cost (Credit)	0	0	0
Amortization of Actuarial (Gains) Losses	0	0	0
Income Tax (Expense) Benefit	0.2	0.3	0.4
Reclassifications from Accumulated Other Comprehensive Income [Member] | Generation and Marketing Revenues [Member]
Commodity
Generation and Marketing Revenues	(0.2)	(0.1)	(5.6)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Generation and Marketing Revenues [Member] | Securities Available for Sale [Member]
Commodity
Generation and Marketing Revenues		0	0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Generation and Marketing Revenues [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Commodity
Generation and Marketing Revenues	0	0	0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Generation and Marketing Revenues [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Commodity
Generation and Marketing Revenues	0	0	0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Generation and Marketing Revenues [Member] | Commodity [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Commodity
Generation and Marketing Revenues	(0.2)	(0.1)	(5.6)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Generation and Marketing Revenues [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Commodity
Generation and Marketing Revenues	0	0	0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale	59.5	(32.6)	28.8
Reclassifications from Accumulated Other Comprehensive Income [Member] | Purchased Electricity for Resale [Member] | Securities Available for Sale [Member]
Commodity
Purchased Electricity for Resale		0	0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Purchased Electricity for Resale [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Commodity
Purchased Electricity for Resale	0	0	0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Purchased Electricity for Resale [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Commodity
Purchased Electricity for Resale	0	0	0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Purchased Electricity for Resale [Member] | Commodity [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Commodity
Purchased Electricity for Resale	59.5	(32.6)	28.8
Reclassifications from Accumulated Other Comprehensive Income [Member] | Purchased Electricity for Resale [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Commodity
Purchased Electricity for Resale	0	0	0
Reclassifications from Accumulated Other Comprehensive Income [Member] | AEP Texas Inc. [Member]
Interest Rate
Interest Expense	1.3	1.3	1.3
Pension and OPEB
Amortization of Prior Service Cost (Credit)	(0.1)	(0.1)	(0.1)
Amortization of Actuarial (Gains) Losses	0.3	0.4	0.5
Income Tax (Expense) Benefit	0.3	0.4	0.5
Reclassifications from Accumulated Other Comprehensive Income [Member] | AEP Texas Inc. [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Interest Rate
Interest Expense	0	0	0
Pension and OPEB
Amortization of Prior Service Cost (Credit)	(0.1)	(0.1)	(0.1)
Amortization of Actuarial (Gains) Losses	0.3	0.4	0.5
Income Tax (Expense) Benefit	0	0.1	0.1
Reclassifications from Accumulated Other Comprehensive Income [Member] | AEP Texas Inc. [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Interest Rate
Interest Expense	0	0	0
Pension and OPEB
Amortization of Prior Service Cost (Credit)	0	0	0
Amortization of Actuarial (Gains) Losses	0	0	0
Income Tax (Expense) Benefit	0	0	0
Reclassifications from Accumulated Other Comprehensive Income [Member] | AEP Texas Inc. [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Interest Rate
Interest Expense	1.3	1.3	1.3
Pension and OPEB
Amortization of Prior Service Cost (Credit)	0	0	0
Amortization of Actuarial (Gains) Losses	0	0	0
Income Tax (Expense) Benefit	0.3	0.3	0.4
Reclassifications from Accumulated Other Comprehensive Income [Member] | Appalachian Power Co [Member]
Interest Rate
Interest Expense	(1.1)	(1.1)	(1.1)
Pension and OPEB
Amortization of Prior Service Cost (Credit)	(5.3)	(5.2)	(5.2)
Amortization of Actuarial (Gains) Losses	2.1	1.3	3.4
Income Tax (Expense) Benefit	(0.9)	(0.8)	(1)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Appalachian Power Co [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Interest Rate
Interest Expense	0	0	0
Pension and OPEB
Amortization of Prior Service Cost (Credit)	(5.3)	(5.2)	(5.2)
Amortization of Actuarial (Gains) Losses	2.1	1.3	3.4
Income Tax (Expense) Benefit	(0.7)	(0.8)	(0.6)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Appalachian Power Co [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Interest Rate
Interest Expense	0	0	0
Pension and OPEB
Amortization of Prior Service Cost (Credit)	0	0	0
Amortization of Actuarial (Gains) Losses	0	0	0
Income Tax (Expense) Benefit	0	0	0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Appalachian Power Co [Member] | Commodity [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Interest Rate
Interest Expense		0
Pension and OPEB
Amortization of Prior Service Cost (Credit)		0
Amortization of Actuarial (Gains) Losses		0
Income Tax (Expense) Benefit		0.2
Reclassifications from Accumulated Other Comprehensive Income [Member] | Appalachian Power Co [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Interest Rate
Interest Expense	(1.1)	(1.1)	(1.1)
Pension and OPEB
Amortization of Prior Service Cost (Credit)	0	0	0
Amortization of Actuarial (Gains) Losses	0	0	0
Income Tax (Expense) Benefit	(0.2)	(0.2)	(0.4)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Appalachian Power Co [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale		0.9
Reclassifications from Accumulated Other Comprehensive Income [Member] | Appalachian Power Co [Member] | Purchased Electricity for Resale [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Commodity
Purchased Electricity for Resale		0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Appalachian Power Co [Member] | Purchased Electricity for Resale [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Commodity
Purchased Electricity for Resale		0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Appalachian Power Co [Member] | Purchased Electricity for Resale [Member] | Commodity [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Commodity
Purchased Electricity for Resale		0.9
Reclassifications from Accumulated Other Comprehensive Income [Member] | Appalachian Power Co [Member] | Purchased Electricity for Resale [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Commodity
Purchased Electricity for Resale		0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Indiana Michigan Power Co [Member]
Interest Rate
Interest Expense	2	2	2
Pension and OPEB
Amortization of Prior Service Cost (Credit)	(0.8)	(0.8)	(0.9)
Amortization of Actuarial (Gains) Losses	0.6	0.8	0.9
Income Tax (Expense) Benefit	0.4	0.4	0.7
Reclassifications from Accumulated Other Comprehensive Income [Member] | Indiana Michigan Power Co [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Interest Rate
Interest Expense	0	0	0
Pension and OPEB
Amortization of Prior Service Cost (Credit)	(0.8)	(0.8)	(0.9)
Amortization of Actuarial (Gains) Losses	0.6	0.8	0.9
Income Tax (Expense) Benefit	0	0	0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Indiana Michigan Power Co [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Interest Rate
Interest Expense	0	0	0
Pension and OPEB
Amortization of Prior Service Cost (Credit)	0	0	0
Amortization of Actuarial (Gains) Losses	0	0	0
Income Tax (Expense) Benefit	0	0	0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Indiana Michigan Power Co [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Interest Rate
Interest Expense	2	2	2
Pension and OPEB
Amortization of Prior Service Cost (Credit)	0	0	0
Amortization of Actuarial (Gains) Losses	0	0	0
Income Tax (Expense) Benefit	0.4	0.4	0.7
Reclassifications from Accumulated Other Comprehensive Income [Member] | Ohio Power Co [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Interest Rate
Interest Expense	(1.3)	(1.7)	(1.7)
Pension and OPEB
Amortization of Actuarial (Gains) Losses	(1.3)
Income Tax (Expense) Benefit	(0.3)	(0.4)	(0.6)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Public Service Co Of Oklahoma [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Interest Rate
Interest Expense	(1.3)	(1.3)	(1.3)
Pension and OPEB
Income Tax (Expense) Benefit	(0.3)	(0.3)	(0.5)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Southwestern Electric Power Co [Member]
Interest Rate
Interest Expense	1.9	2.1	2.2
Pension and OPEB
Amortization of Prior Service Cost (Credit)	(2)	(2)	(2)
Amortization of Actuarial (Gains) Losses	0.6	0.2	0.9
Income Tax (Expense) Benefit	0.1	0	0.4
Reclassifications from Accumulated Other Comprehensive Income [Member] | Southwestern Electric Power Co [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Interest Rate
Interest Expense	0	0	0
Pension and OPEB
Amortization of Prior Service Cost (Credit)	(2)	(2)	(2)
Amortization of Actuarial (Gains) Losses	0.6	0.2	0.9
Income Tax (Expense) Benefit	(0.3)	(0.4)	(0.4)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Southwestern Electric Power Co [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Interest Rate
Interest Expense	0	0	0
Pension and OPEB
Amortization of Prior Service Cost (Credit)	0	0	0
Amortization of Actuarial (Gains) Losses	0	0	0
Income Tax (Expense) Benefit	0	0	0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Southwestern Electric Power Co [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Interest Rate
Interest Expense	1.9	2.1	2.2
Pension and OPEB
Amortization of Prior Service Cost (Credit)	0	0	0
Amortization of Actuarial (Gains) Losses	0	0	0
Income Tax (Expense) Benefit	$ 0.4	$ 0.4	$ 0.8

Rate Matters East Companies (De

Rate Matters East Companies (Details) - USD ($) $ in Millions	2 Months Ended	12 Months Ended
	Feb. 20, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Public Utilities, General Disclosures [Line Items]
Asset Impairments and Other Related Charges		$ 156.4	$ 70.6	$ 87.1
Total Property, Plant and Equipment, Net		60,138.1	55,099.1
Accumulated Depreciation and Amortization		19,007.6	17,986.1
Construction Work in Progress		4,319.8	4,393.9
AEP Transmission Co [Member]
Public Utilities, General Disclosures [Line Items]
Total Property, Plant and Equipment, Net		9,490.9	7,996.2
Accumulated Depreciation and Amortization		402.3	271.9
Construction Work in Progress		1,485.7	1,578.3
Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Asset Impairments and Other Related Charges		92.9	0	$ 0
Total Property, Plant and Equipment, Net		11,081.9	10,668.3
Accumulated Depreciation and Amortization		4,432.3	4,124.4
Construction Work in Progress		593.4	490.2
Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Total Property, Plant and Equipment, Net		6,899.7	6,611.2
Accumulated Depreciation and Amortization		3,294.3	3,151.6
Construction Work in Progress		382.3	465.3
Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Total Property, Plant and Equipment, Net		6,907	6,274.9
Accumulated Depreciation and Amortization		2,263	2,218.6
Construction Work in Progress		$ 394.4	$ 432.1
Virginia Legislation Affecting Earnings Reviews [Member]
Public Utilities, General Disclosures [Line Items]
Percent of Excess Earnings Subject to Refund		70.00%
Basis Points Over Authorized Return on Equity Considered Excess Earnings		70.00%
Approved Return on Common Equity		9.42%
Virginia Legislation Affecting Earnings Reviews [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Percent of Excess Earnings Subject to Refund		70.00%
Basis Points Over Authorized Return on Equity Considered Excess Earnings		70.00%
Approved Return on Common Equity		9.42%
Virginia Staff Depreciation Study Request [Member]
Public Utilities, General Disclosures [Line Items]
Potential Increase to Total Annual Depreciation Rates		$ 21
Potential Increase to Annual Transmission Depreciation Rates		6
Virginia Staff Depreciation Study Request [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Potential Increase to Total Annual Depreciation Rates		21
Potential Increase to Annual Transmission Depreciation Rates		6
Virginia Tax Reform [Member]
Public Utilities, General Disclosures [Line Items]
Refund Due to Tax Reform		40
Refund for Excess ADIT Associated with Certain Depreciable Property		9
Refund for Excess ADIT Not Subject to Rate Normalization Requirements		94
One Time Refund of Estimated Excess Taxes Collected		22
Virginia Tax Reform [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Refund Due to Tax Reform		40
Refund for Excess ADIT Associated with Certain Depreciable Property		9
Refund for Excess ADIT Not Subject to Rate Normalization Requirements		94
One Time Refund of Estimated Excess Taxes Collected		$ 22
2018 West Virginia Base Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Approved Return on Common Equity		9.75%
Refund for Excess ADIT Not Subject to Rate Normalization Requirements		$ 24
Amount of Increase Related to Annual Depreciation Rates		32
Requested Annual Increase		$ 115
Requested Return on Equity		10.22%
Approved Amount of Increase Related to Annual Depreciation Rates		$ 18
Regulatory Assets Used to Offset Tax Savings and Excess ADIT Due to Tax Reform		14
Adjusted Annual Increase Request due to Tax Reform		95
Approved Annual Revenue Increase		$ 44
2018 West Virginia Base Rate Case [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Approved Return on Common Equity		9.75%
Refund for Excess ADIT Not Subject to Rate Normalization Requirements		$ 19
Amount of Increase Related to Annual Depreciation Rates		28
Requested Annual Increase		$ 98
Requested Return on Equity		10.22%
Approved Amount of Increase Related to Annual Depreciation Rates		$ 14
Regulatory Assets Used to Offset Tax Savings and Excess ADIT Due to Tax Reform		12
Adjusted Annual Increase Request due to Tax Reform		80
Approved Annual Revenue Increase		36
Michigan Tax Reform [Member]
Public Utilities, General Disclosures [Line Items]
Refund for Excess ADIT Associated with Certain Depreciable Property		48
Refund for Excess ADIT Not Subject to Rate Normalization Requirements		28
Michigan Tax Reform [Member] | Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Refund for Excess ADIT Associated with Certain Depreciable Property		48
Refund for Excess ADIT Not Subject to Rate Normalization Requirements		28
2019 Indiana Base Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Amount of Increase Related to Annual Depreciation Rates		78
Amount of Increase Related to Annual Depreciation Rates due to Proposed Investments		52
Amount of Increase Related to Annual Depreciation Rates due to Increased Depreciation Expense		26
Requested Annual Increase		$ 172
Requested Return on Equity		10.50%
2019 Indiana Base Rate Case [Member] | Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Amount of Increase Related to Annual Depreciation Rates		$ 78
Amount of Increase Related to Annual Depreciation Rates due to Proposed Investments		52
Amount of Increase Related to Annual Depreciation Rates due to Increased Depreciation Expense		26
Requested Annual Increase		$ 172
Requested Return on Equity		10.50%
2019 Michigan Base Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Amount of Increase Related to Annual Depreciation Rates		$ 19
Amount of Increase Related to Annual Depreciation Rates due to Proposed Investments		13
Amount of Increase Related to Annual Depreciation Rates due to Increased Depreciation Expense		6
Amount of Increase Related to Lost Revenue due to Michigan Electric Customer Choice Program		10
Requested Annual Increase		$ 58
Requested Return on Equity		10.50%
2019 Michigan Base Rate Case [Member] | Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Amount of Increase Related to Annual Depreciation Rates		$ 19
Amount of Increase Related to Annual Depreciation Rates due to Proposed Investments		13
Amount of Increase Related to Annual Depreciation Rates due to Increased Depreciation Expense		6
Amount of Increase Related to Lost Revenue due to Michigan Electric Customer Choice Program		10
Requested Annual Increase		$ 58
Requested Return on Equity		10.50%
2016 SEET Filing [Member]
Public Utilities, General Disclosures [Line Items]
Provision for Refund		$ 58
2016 SEET Filing [Member] | Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Provision for Refund		$ 58
FERC Transmission Complaint [Member]
Public Utilities, General Disclosures [Line Items]
Approved Return on Common Equity		10.99%
Intervenor Recommended Return on Common Equity		8.32%
Return On Common Equity Per Settlement Agreement		9.85%
Return on Common Equity Inclusive of RTO Per Settlement Agreement		10.35%
RTO Incentive Adder Per Settlement Agreement		0.50%
One Time Refund to Customers Per Settlement Agreement		$ 50
Increased Cap on Equity Portion of the Capital Structure Per Settlement Agreement		55.00%
Original Cap on Equity Portion of the Capital Structure Prior to Settlement Agreement		50.00%
Subsequent Event [Member] | 2019 Michigan Base Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Approved Return on Common Equity	9.86%
Approved Annual Revenue Increase	$ 36
Subsequent Event [Member] | 2019 Michigan Base Rate Case [Member] | Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Approved Return on Common Equity	9.86%
Approved Annual Revenue Increase	$ 36
Minimum [Member] | 2019 Indiana Base Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Intervenor Recommended Annual Increase		$ 2
Intervenor Recommended Return on Common Equity		9.00%
Minimum [Member] | 2019 Indiana Base Rate Case [Member] | Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Intervenor Recommended Annual Increase		$ 2
Intervenor Recommended Return on Common Equity		9.00%
Maximum [Member] | 2019 Indiana Base Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Intervenor Recommended Annual Increase		$ 33
Intervenor Recommended Return on Common Equity		9.73%
Maximum [Member] | 2019 Indiana Base Rate Case [Member] | Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Intervenor Recommended Annual Increase		$ 33
Intervenor Recommended Return on Common Equity		9.73%
Indiana Jurisdictional Meters [Member] | 2019 Indiana Base Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Recommended Disallowance		$ 41
Indiana Jurisdictional Meters [Member] | 2019 Indiana Base Rate Case [Member] | Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Recommended Disallowance		41
Cook Plant Study Costs [Member] | 2019 Indiana Base Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Recommended Disallowance		11
Cook Plant Study Costs [Member] | 2019 Indiana Base Rate Case [Member] | Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Recommended Disallowance		11
Plant Retirement Costs - Unrecovered Plant [Member]
Public Utilities, General Disclosures [Line Items]
Net Book Value of Retired Plants		93
Asset Impairments and Other Related Charges		93
Accumulated Depreciation and Amortization		91
Plant Retirement Costs - Unrecovered Plant [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Net Book Value of Retired Plants		93
Asset Impairments and Other Related Charges		93
Accumulated Depreciation and Amortization		91
Plant Retirement Costs - Unrecovered Plant [Member] | Virginia Legislation Affecting Earnings Reviews [Member]
Public Utilities, General Disclosures [Line Items]
Net Book Value of Retired Plants		93
Asset Impairments and Other Related Charges		93
Plant Retirement Costs - Unrecovered Plant [Member] | Virginia Legislation Affecting Earnings Reviews [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Net Book Value of Retired Plants		93
Asset Impairments and Other Related Charges		93
Virginia Jurisdictional AMR Meters [Member]
Public Utilities, General Disclosures [Line Items]
Total Property, Plant and Equipment, Net		51
Virginia Jurisdictional AMR Meters [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Total Property, Plant and Equipment, Net		51
Virginia Jurisdictional AMR Meters [Member] | Virginia Legislation Affecting Earnings Reviews [Member]
Public Utilities, General Disclosures [Line Items]
Total Property, Plant and Equipment, Net		27
Virginia Jurisdictional AMR Meters [Member] | Virginia Legislation Affecting Earnings Reviews [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Total Property, Plant and Equipment, Net		$ 27

Rate Matters West Companies (De

Rate Matters West Companies (Details) - USD ($) $ in Millions	2 Months Ended	12 Months Ended
	Feb. 20, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Public Utilities, General Disclosures [Line Items]
Secured Debt		$ 1,025.1	$ 1,111.4
Asset Impairments and Other Related Charges		156.4	70.6	$ 87.1
Construction Work in Progress		4,319.8	4,393.9
AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Secured Debt		776.8	791.2
Asset Impairments and Other Related Charges		32.5	0	0
Construction Work in Progress		763.9	836.2
Public Service Co Of Oklahoma [Member]
Public Utilities, General Disclosures [Line Items]
Provision for Refund		(9.1)	3.8	(43.5)
Construction Work in Progress		133.4	94
Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Asset Impairments and Other Related Charges		0	0	33.6
Provision for Refund		(32)	(6.7)	$ 0
Construction Work in Progress		216.9	$ 199.3
AEP Texas Interim Transmission and Distribution Rates [Member]
Public Utilities, General Disclosures [Line Items]
AEP Texas Cumulative Revenues Subject to Review		1,400
AEP Texas Interim Transmission and Distribution Rates [Member] | AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
AEP Texas Cumulative Revenues Subject to Review		1,400
2019 Texas Base Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
ALJ Recommended Annual Decrease		$ 60
ALJ Recommended Return on Common Equity		9.40%
Requested Annual Increase		$ 56
Requested Return on Equity		10.50%
Refund for Excess ADIT		$ 21
Asset Impairments and Other Related Charges		33
Refund for Excess ADIT Associated with Certain Depreciable Property		275
2019 Texas Base Rate Case [Member] | Previously Collected Rates Subject to Reconciliation [Member]
Public Utilities, General Disclosures [Line Items]
Provision for Refund		30
2019 Texas Base Rate Case [Member] | Capital Incentives [Member]
Public Utilities, General Disclosures [Line Items]
Recommended Disallowance from ALJ		84
2019 Texas Base Rate Case [Member] | Other Plant Additions [Member]
Public Utilities, General Disclosures [Line Items]
Recommended Disallowance from ALJ		5
2019 Texas Base Rate Case [Member] | Rate Case Expense [Member]
Public Utilities, General Disclosures [Line Items]
Write-off of Regulatory Expense		4
2019 Texas Base Rate Case [Member] | Amount of 2019 Investments [Member]
Public Utilities, General Disclosures [Line Items]
Asset Impairments and Other Related Charges		10
2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
ALJ Recommended Annual Decrease		$ 60
ALJ Recommended Return on Common Equity		9.40%
Requested Annual Increase		$ 56
Requested Return on Equity		10.50%
Refund for Excess ADIT		$ 21
Asset Impairments and Other Related Charges		33
Refund for Excess ADIT Associated with Certain Depreciable Property		275
2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member] | Previously Collected Rates Subject to Reconciliation [Member]
Public Utilities, General Disclosures [Line Items]
Provision for Refund		30
2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member] | Capital Incentives [Member]
Public Utilities, General Disclosures [Line Items]
Recommended Disallowance from ALJ		84
2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member] | Other Plant Additions [Member]
Public Utilities, General Disclosures [Line Items]
Recommended Disallowance from ALJ		5
2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member] | Rate Case Expense [Member]
Public Utilities, General Disclosures [Line Items]
Write-off of Regulatory Expense		4
2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member] | Amount of 2019 Investments [Member]
Public Utilities, General Disclosures [Line Items]
Asset Impairments and Other Related Charges		10
Texas Storm Cost Securitization [Member]
Public Utilities, General Disclosures [Line Items]
Excess ADIT		64
Secured Debt		235
Texas Restoration Carrying Costs		33
Debt Carrying Costs Recorded as Reduction to Interest Expense		21
Transmission Related Assets to be Recovered at a Later Time		95
Texas Storm Cost Securitization [Member] | AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Excess ADIT		64
Secured Debt		235
Texas Restoration Carrying Costs		33
Debt Carrying Costs Recorded as Reduction to Interest Expense		21
Transmission Related Assets to be Recovered at a Later Time		$ 95
ETT Interim Transmission Rates [Member]
Public Utilities, General Disclosures [Line Items]
Parent Ownership Interest In ETT		50.00%
AEP Share Of ETT Cumulative Revenues Subject To Review		$ 1,000
2018 Oklahoma Base Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase		$ 88
Requested Return on Equity		10.30%
Amount Of Increased Depreciation Expense Requested		$ 13
Amount of Increase Related to Increased Storm Expense Amortization		7
Approved Annual Revenue Increase		$ 46
Approved Return on Common Equity		9.40%
Revenue Cap on New Distribution Reliability and Safety Rider		$ 5
2018 Oklahoma Base Rate Case [Member] | Public Service Co Of Oklahoma [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase		$ 88
Requested Return on Equity		10.30%
Amount Of Increased Depreciation Expense Requested		$ 13
Amount of Increase Related to Increased Storm Expense Amortization		7
Approved Annual Revenue Increase		$ 46
Approved Return on Common Equity		9.40%
Revenue Cap on New Distribution Reliability and Safety Rider		$ 5
2012 Texas Base Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
2013 Reversal Of Previously Recorded Regulatory Disallowances		114
Resulting Approved Base Rate Increase		52
2012 Texas Base Rate Case [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
2013 Reversal Of Previously Recorded Regulatory Disallowances		114
Resulting Approved Base Rate Increase		52
2012 Texas Base Rate Case [Member] | Turk Generating Plant [Member]
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net		$ 1,500
Texas Jurisdictional Share of Turk Plant		33.00%
2012 Texas Base Rate Case [Member] | Turk Generating Plant [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net		$ 1,500
Texas Jurisdictional Share of Turk Plant		33.00%
2016 Texas Base Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Requested Return on Equity		10.00%
Approved Return on Common Equity		9.60%
Requested Net Increase in Texas Annual Revenues		$ 69
Approved Net Increase in Texas Annual Revenues		50
Approved Additional Vegetation Management Expenses		2
Impairment Charge Total		19
Impairment Charge Welsh Plant, Unit 2		7
Impairment Charge Disallowed Plant Investments		12
Additional Revenues Recognized to be Surcharged to Customers		32
Additional Recognized Expenses Consisting Primarily of Depreciation and Vegetation Management		$ 7
2016 Texas Base Rate Case [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Requested Return on Equity		10.00%
Approved Return on Common Equity		9.60%
Requested Net Increase in Texas Annual Revenues		$ 69
Approved Net Increase in Texas Annual Revenues		50
Approved Additional Vegetation Management Expenses		2
Impairment Charge Total		19
Impairment Charge Welsh Plant, Unit 2		7
Impairment Charge Disallowed Plant Investments		12
Additional Revenues Recognized to be Surcharged to Customers		32
Additional Recognized Expenses Consisting Primarily of Depreciation and Vegetation Management		7
Louisiana 2018 Formula Rate Filing [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase		28
Adjusted Requested Annual Increase		18
Refund for Current Year Tax Reform Rate Change		11
Additional Refund for Current Year Tax Reform Rate Change		4
Staff Recommended Annual Rate Increase		14
Louisiana 2018 Formula Rate Filing [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase		28
Adjusted Requested Annual Increase		18
Refund for Current Year Tax Reform Rate Change		11
Additional Refund for Current Year Tax Reform Rate Change		4
Staff Recommended Annual Rate Increase		14
Welsh Plant, Units 1 And 3 - Environmental Projects [Member] | Welsh Plant, Units 1 and 3 [Member]
Public Utilities, General Disclosures [Line Items]
Projected Capital Costs		520
Construction Work in Progress		399
Total Amount of Welsh Environmental Project Approved For Recovery		340
Welsh Plant, Units 1 And 3 - Environmental Projects [Member] | Welsh Plant, Units 1 and 3 [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Projected Capital Costs		520
Construction Work in Progress		399
Total Amount of Welsh Environmental Project Approved For Recovery		340
2019 Arkansas Base Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase		$ 75
Requested Return on Equity		10.50%
Approved Annual Revenue Increase		$ 53
Approved Annual Revenue Increase - Net		$ 24
Approved Return on Common Equity		9.45%
Approved Increase in Annual Depreciation Expense		$ 6
Adjusted Requested Annual Increase		67
Requested Annual Net Increase		58
Requested Additional Vegetation Management Expenses		12
2019 Arkansas Base Rate Case [Member] | Capital Investments [Member]
Public Utilities, General Disclosures [Line Items]
Disallowed Item in Commission Order		4
2019 Arkansas Base Rate Case [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase		$ 75
Requested Return on Equity		10.50%
Approved Annual Revenue Increase		$ 53
Approved Annual Revenue Increase - Net		$ 24
Approved Return on Common Equity		9.45%
Approved Increase in Annual Depreciation Expense		$ 6
Adjusted Requested Annual Increase		67
Requested Annual Net Increase		58
Requested Additional Vegetation Management Expenses		12
2019 Arkansas Base Rate Case [Member] | Southwestern Electric Power Co [Member] | Capital Investments [Member]
Public Utilities, General Disclosures [Line Items]
Disallowed Item in Commission Order		$ 4
FERC Transmission Complaint - AEP SPP Participants [Member]
Public Utilities, General Disclosures [Line Items]
Approved Return on Common Equity		10.70%
Intervenor Recommended Return On Common Equity Range		8.36%
Second Intervenor Recommended Return on Common Equity		8.71%
Return On Common Equity Per Settlement Agreement		10.00%
Return on Common Equity Inclusive of RTO Per Settlement Agreement		10.50%
RTO Incentive Adder Per Settlement Agreement		0.50%
Subsequent Event [Member] | 2019 Texas Base Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Settlement Agreement Annual Decrease	$ 40
Settlement Agreement Return on Common Equity	9.40%
Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | Debt [Member]
Public Utilities, General Disclosures [Line Items]
Settlement Agreement Capital Structure	57.50%
Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | Equity [Member]
Public Utilities, General Disclosures [Line Items]
Settlement Agreement Capital Structure	42.50%
Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | Excess ADIT and Excess Federal Income Taxes to Distribution Customers [Member]
Public Utilities, General Disclosures [Line Items]
Settlement Agreement Refund to Customers	$ 77
Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | Excess ADIT and Excess Federal Income Taxes to Transmission Customers [Member]
Public Utilities, General Disclosures [Line Items]
Settlement Agreement Refund to Customers	31
Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | Previously Collected Rates Subject to Reconciliation [Member]
Public Utilities, General Disclosures [Line Items]
Settlement Agreement Refund to Customers	30
Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | Vegetation Management [Member]
Public Utilities, General Disclosures [Line Items]
Settlement Agreement Approved for Recovery	26
Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | Capital Investments [Member]
Public Utilities, General Disclosures [Line Items]
Settlement Agreement Disallowance	23
Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | Rate Case Expense [Member]
Public Utilities, General Disclosures [Line Items]
Settlement Agreement Disallowance	4
Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Settlement Agreement Annual Decrease	$ 40
Settlement Agreement Return on Common Equity	9.40%
Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member] | Debt [Member]
Public Utilities, General Disclosures [Line Items]
Settlement Agreement Capital Structure	57.50%
Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member] | Equity [Member]
Public Utilities, General Disclosures [Line Items]
Settlement Agreement Capital Structure	42.50%
Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member] | Excess ADIT and Excess Federal Income Taxes to Distribution Customers [Member]
Public Utilities, General Disclosures [Line Items]
Settlement Agreement Refund to Customers	$ 77
Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member] | Excess ADIT and Excess Federal Income Taxes to Transmission Customers [Member]
Public Utilities, General Disclosures [Line Items]
Settlement Agreement Refund to Customers	31
Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member] | Previously Collected Rates Subject to Reconciliation [Member]
Public Utilities, General Disclosures [Line Items]
Settlement Agreement Refund to Customers	30
Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member] | Vegetation Management [Member]
Public Utilities, General Disclosures [Line Items]
Settlement Agreement Approved for Recovery	26
Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member] | Capital Investments [Member]
Public Utilities, General Disclosures [Line Items]
Settlement Agreement Disallowance	23
Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member] | Rate Case Expense [Member]
Public Utilities, General Disclosures [Line Items]
Settlement Agreement Disallowance	$ 4

Effects of Regulation (Details)

Effects of Regulation (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Regulated Generating Unit to be Retired
Gross Investment		$ 22,762.4	$ 21,699.9
Accumulated Depreciation and Amortization		19,007.6	17,986.1
Total Property, Plant and Equipment, Net		60,138.1	55,099.1
Materials and Supplies		640.7	602.1
Regulatory Assets
Current Regulatory Assets		92.9	150.1
Noncurrent Regulatory Assets		3,158.8	3,310.4
Regulatory Liabilities
Current Regulatory Liabilities		86.6	58.6
Noncurrent Regulatory Liabilities		8,457.6	8,540.3
Effects of Regulation Textuals [Abstract]
Secured Debt		1,025.1	1,111.4
Accumulated Depreciation and Amortization		19,007.6	17,986.1
Asset Impairments and Other Related Charges		$ 156.4	$ 70.6	$ 87.1
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	21.00%	35.00%
Share of Net Investment in Dolet Hills Power Station		$ 157
Dolet Hills Lignite Company Unbilled Fixed Costs		106
Oxbow Unbilled Fixed Costs		22
AEP Texas Inc. [Member]
Regulated Generating Unit to be Retired
Gross Investment		351.7	$ 352.1
Accumulated Depreciation and Amortization		1,758.1	1,651.2
Total Property, Plant and Equipment, Net		8,845.1	7,991.8
Materials and Supplies		56.7	52.8
Regulatory Assets
Noncurrent Regulatory Assets		280.6	430
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1,316.9	1,344.3
Effects of Regulation Textuals [Abstract]
Secured Debt		776.8	791.2
Accumulated Depreciation and Amortization		1,758.1	1,651.2
Asset Impairments and Other Related Charges		$ 32.5	$ 0	$ 0
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	21.00%	35.00%
AEP Transmission Co [Member]
Regulated Generating Unit to be Retired
Accumulated Depreciation and Amortization		$ 402.3	$ 271.9
Total Property, Plant and Equipment, Net		9,490.9	7,996.2
Materials and Supplies		13.8	19
Regulatory Assets
Noncurrent Regulatory Assets		4.2	12.9
Regulatory Liabilities
Noncurrent Regulatory Liabilities		540.9	521.3
Effects of Regulation Textuals [Abstract]
Accumulated Depreciation and Amortization		$ 402.3	$ 271.9
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	21.00%	35.00%
Appalachian Power Co [Member]
Regulated Generating Unit to be Retired
Gross Investment		$ 6,563.7	$ 6,509.6
Accumulated Depreciation and Amortization		4,432.3	4,124.4
Total Property, Plant and Equipment, Net		11,081.9	10,668.3
Materials and Supplies		105.2	100.1
Regulatory Assets
Current Regulatory Assets		42.5	99.6
Noncurrent Regulatory Assets		457.2	475.8
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1,268.7	1,449.7
Effects of Regulation Textuals [Abstract]
Secured Debt		248.3	272.3
Accumulated Depreciation and Amortization		4,432.3	4,124.4
Asset Impairments and Other Related Charges		$ 92.9	$ 0	$ 0
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	21.00%	35.00%
Indiana Michigan Power Co [Member]
Regulated Generating Unit to be Retired
Gross Investment		$ 5,099.7	$ 4,887.2
Accumulated Depreciation and Amortization		3,294.3	3,151.6
Total Property, Plant and Equipment, Net		6,899.7	6,611.2
Materials and Supplies		171.3	167.3
Regulatory Assets
Current Regulatory Assets		3	0
Noncurrent Regulatory Assets		482.1	512.5
Regulatory Liabilities
Current Regulatory Liabilities		6.1	27.4
Noncurrent Regulatory Liabilities		1,891.4	1,574.5
Effects of Regulation Textuals [Abstract]
Accumulated Depreciation and Amortization		$ 3,294.3	$ 3,151.6
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	21.00%	35.00%
Ohio Power Co [Member]
Regulated Generating Unit to be Retired
Accumulated Depreciation and Amortization		$ 2,263	$ 2,218.6
Total Property, Plant and Equipment, Net		6,907	6,274.9
Materials and Supplies		52.3	42.9
Regulatory Assets
Current Regulatory Assets		0	0.4
Noncurrent Regulatory Assets		351.8	387.5
Regulatory Liabilities
Current Regulatory Liabilities		2.8	0
Noncurrent Regulatory Liabilities		1,090.9	1,221.2
Effects of Regulation Textuals [Abstract]
Secured Debt		0	47.8
Accumulated Depreciation and Amortization		$ 2,263	$ 2,218.6
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	21.00%	35.00%
Public Service Co Of Oklahoma [Member]
Regulated Generating Unit to be Retired
Gross Investment		$ 1,574.6	$ 1,577
Accumulated Depreciation and Amortization		1,580.1	1,472.9
Total Property, Plant and Equipment, Net		4,103.3	3,966.7
Materials and Supplies		46.8	44.8
Regulatory Assets
Noncurrent Regulatory Assets		375.2	369
Regulatory Liabilities
Current Regulatory Liabilities		63.9	20.1
Noncurrent Regulatory Liabilities		837.2	864.7
Effects of Regulation Textuals [Abstract]
Accumulated Depreciation and Amortization		$ 1,580.1	$ 1,472.9
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	21.00%	35.00%
Southwestern Electric Power Co [Member]
Regulated Generating Unit to be Retired
Gross Investment		$ 4,691.4	$ 4,672.6
Accumulated Depreciation and Amortization		2,873.7	2,808.3
Total Property, Plant and Equipment, Net		7,095.2	6,871.8
Materials and Supplies		94	90
Regulatory Assets
Current Regulatory Assets		4.9	18.8
Noncurrent Regulatory Assets		222.4	230.8
Regulatory Liabilities
Current Regulatory Liabilities		13.6	11.1
Noncurrent Regulatory Liabilities		892.3	923
Effects of Regulation Textuals [Abstract]
Accumulated Depreciation and Amortization		2,873.7	2,808.3
Asset Impairments and Other Related Charges		$ 0	$ 0	$ 33.6
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	21.00%	35.00%
Share of Net Investment in Dolet Hills Power Station		$ 157
Dolet Hills Lignite Company Unbilled Fixed Costs		106
Oxbow Unbilled Fixed Costs		22
Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		7,594.6	$ 6,819.8
Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		954.9	925.8
Regulatory Liabilities Approved for Payment [Member] | AEP Transmission Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		540.9	442.9
Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1,268.7	897.8
Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1,891.4	1,408.9
Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1,090.7	1,221
Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		837.2	864.7
Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		572.6	616
Regulatory Liabilities Pending Final Regulatory Determination [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		863	1,720.5
Regulatory Liabilities Pending Final Regulatory Determination [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		362	418.5
Regulatory Liabilities Pending Final Regulatory Determination [Member] | AEP Transmission Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		0	78.4
Regulatory Liabilities Pending Final Regulatory Determination [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		0	551.9
Regulatory Liabilities Pending Final Regulatory Determination [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		0	165.6
Regulatory Liabilities Pending Final Regulatory Determination [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		0.2	0.2
Regulatory Liabilities Pending Final Regulatory Determination [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		319.7	307
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1,808.4	1,477.8
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		64.9	56.8
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		65.6	106.4
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1,370	953.9
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		81.7	148.4
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		56.2	54
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		10.8	9.4
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		0.2	0.2
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		2,934.5	2,838.1
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		699.7	660
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Transmission Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		141	99.5
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		635.8	619.3
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		167	182.5
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		484.8	505.8
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		286.8	276.8
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		456.2	440.3
Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		2,851.7	2,503.9
Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		190.3	209
Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Transmission Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		399.9	343.4
Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		567.3	172.1
Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		354.4	272.5
Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		524.2	566.8
Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		494.2	533.9
Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		105.6	166.3
Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		862.8	1,720.3
Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		181.7	288
Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		30.8	152.6
Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		30.6	44.9
Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		7.7	3.3
Regulatory Assets Pending Final Regulatory Approval [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		0.1	1
Regulatory Assets Pending Final Regulatory Approval [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		34.6	6
Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		46.3	64.4
Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		2,977.1	3,022.4
Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		249.8	277.4
Regulatory Assets Approved for Recovery [Member] | AEP Transmission Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		4.2	12.9
Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		426.6	430.9
Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		474.4	509.2
Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		351.7	386.5
Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		340.6	363
Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		176.1	166.4
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		93.5	79.6
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		0.5	9
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		27.4	5.5
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		35.4	50.6
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		1,089.2	1,139.5
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		61.7	85.4
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		86.9	86.5
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		296.4	318.7
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		31.4	71
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		255.3	257.1
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		37.2	21.4
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		88.2	208.4
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		30.1	35.9
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		7.2	0.5
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		10.9	13.8
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		1,887.9	1,882.9
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		188.1	192
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		339.7	344.4
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		178	190.5
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		320.3	315.5
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		85.3	105.9
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		138.9	145
Oklaunion Power Station [Member] | Generating Units Probable of Abandonment [Member]
Regulated Generating Unit to be Retired
Gross Investment		106.7
Accumulated Depreciation and Amortization		86.6
Total Property, Plant and Equipment, Net		20.1
Accelerated Depreciation		27.4
Materials and Supplies		3.2
Cost of Removal Regulatory Liability		$ 5.1
Expected Retirement Date		2020
Remaining Recovery Period, Plant Depreciation		27 years
Effects of Regulation Textuals [Abstract]
Accumulated Depreciation and Amortization		$ 86.6
Oklaunion Power Station [Member] | Generating Units Probable of Abandonment [Member] | Public Service Co Of Oklahoma [Member]
Regulated Generating Unit to be Retired
Gross Investment		106.7
Accumulated Depreciation and Amortization		86.6
Total Property, Plant and Equipment, Net		20.1
Accelerated Depreciation	[1]	27.4
Materials and Supplies		3.2
Cost of Removal Regulatory Liability		$ 5.1
Expected Retirement Date		2020
Remaining Recovery Period, Plant Depreciation		27 years
Effects of Regulation Textuals [Abstract]
Accumulated Depreciation and Amortization		$ 86.6
Dolet Hills Power Station [Member] | Generating Units Probable of Abandonment [Member]
Regulated Generating Unit to be Retired
Gross Investment		338.9
Accumulated Depreciation and Amortization		194.2
Total Property, Plant and Equipment, Net		144.7
Accelerated Depreciation		0
Materials and Supplies		5.8
Cost of Removal Regulatory Liability		$ 23.6
Expected Retirement Date		2026
Remaining Recovery Period, Plant Depreciation		27 years
Effects of Regulation Textuals [Abstract]
Accumulated Depreciation and Amortization		$ 194.2
Dolet Hills Power Station [Member] | Generating Units Probable of Abandonment [Member] | Southwestern Electric Power Co [Member]
Regulated Generating Unit to be Retired
Gross Investment		338.9
Accumulated Depreciation and Amortization		194.2
Total Property, Plant and Equipment, Net		144.7
Accelerated Depreciation	[2]	0
Materials and Supplies		5.8
Cost of Removal Regulatory Liability		$ 23.6
Expected Retirement Date		2026
Remaining Recovery Period, Plant Depreciation		27 years
Effects of Regulation Textuals [Abstract]
Accumulated Depreciation and Amortization		$ 194.2
Deferred Fuel Costs [Member] | Regulatory Liabilities Currently Not Paying Return [Member]
Regulatory Liabilities
Current Regulatory Liabilities		$ 9.1	22.9
Remaining Refund Period		1 year
Deferred Fuel Costs [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Current Regulatory Liabilities		$ 6.1	22.9
Remaining Refund Period		1 year
Deferred Fuel Costs [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Current Regulatory Liabilities		$ 2.8	0
Remaining Refund Period		1 year
Deferred Fuel Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member]
Regulatory Liabilities
Current Regulatory Liabilities		$ 77.5	35.7
Remaining Refund Period		1 year
Deferred Fuel Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Current Regulatory Liabilities		$ 0	4.5
Deferred Fuel Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Liabilities
Current Regulatory Liabilities		$ 63.9	20.1
Remaining Refund Period		1 year
Deferred Fuel Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Current Regulatory Liabilities		$ 13.6	11.1
Remaining Refund Period		1 year
Deferred Fuel Costs [Member] | Regulatory Assets Currently Earning Return [Member]
Regulatory Assets
Current Regulatory Assets		$ 44.7	101.7
Regulatory Asset, Amortization Period		1 year
Deferred Fuel Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Appalachian Power Co [Member]
Regulatory Assets
Current Regulatory Assets		$ 36.8	82.4
Regulatory Asset, Amortization Period		1 year
Deferred Fuel Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Current Regulatory Assets		$ 3	0
Regulatory Asset, Amortization Period		1 year
Deferred Fuel Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Ohio Power Co [Member]
Regulatory Assets
Current Regulatory Assets		$ 0	0.4
Deferred Fuel Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Current Regulatory Assets		$ 4.9	18.8
Regulatory Asset, Amortization Period		1 year
Deferred Fuel Costs [Member] | Regulatory Assets Currently Not Earning Return [Member]
Regulatory Assets
Current Regulatory Assets		$ 48.2	48.4
Regulatory Asset, Amortization Period		1 year
Deferred Fuel Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Appalachian Power Co [Member]
Regulatory Assets
Current Regulatory Assets		$ 5.7	17.2
Regulatory Asset, Amortization Period		1 year
Plant Retirement Costs - Unrecovered Plant [Member]
Regulated Generating Unit to be Retired
Accumulated Depreciation and Amortization		$ 91
Effects of Regulation Textuals [Abstract]
Accumulated Depreciation and Amortization		91
Net Book Value of Retired Plants		93
Asset Impairments and Other Related Charges		93
Plant Retirement Costs - Unrecovered Plant [Member] | Appalachian Power Co [Member]
Regulated Generating Unit to be Retired
Accumulated Depreciation and Amortization		91
Effects of Regulation Textuals [Abstract]
Accumulated Depreciation and Amortization		91
Net Book Value of Retired Plants		93
Asset Impairments and Other Related Charges		93
Plant Retirement Costs - Unrecovered Plant [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Effects of Regulation Textuals [Abstract]
Cost of Removal		11	20
Plant Retirement Costs - Unrecovered Plant [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]
Effects of Regulation Textuals [Abstract]
Cost of Removal		11	20
Plant Retirement Costs - Unrecovered Plant [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		35.2	50.3
Plant Retirement Costs - Unrecovered Plant [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		35.2	50.3
Plant Retirement Costs - Unrecovered Plant [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 690.5	680.9
Regulatory Asset, Amortization Period		23 years
Plant Retirement Costs - Unrecovered Plant [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 86.4	85.3
Regulatory Asset, Amortization Period		24 years
Plant Retirement Costs - Unrecovered Plant [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 214.9	232.2
Regulatory Asset, Amortization Period		9 years
Plant Retirement Costs - Unrecovered Plant [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 167	153.4
Regulatory Asset, Amortization Period		21 years
Plant Retirement Costs - Unrecovered Plant [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 15.1	0
Regulatory Asset, Amortization Period		23 years
Plant Retirement Costs - Unrecovered Plant [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 16.6	17.1
Regulatory Asset, Amortization Period		22 years
Kentucky Deferred Purchase Power Expenses [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 30.2	14.5
Oklaunion Power Station Accelerated Depreciation [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		27.4	5.5
Oklaunion Power Station Accelerated Depreciation [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		27.4	5.5
Other Regulatory Assets Not Yet Being Recovered [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		0.7	9.3
Other Regulatory Assets Not Yet Being Recovered [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		0.2	0.3
Other Regulatory Assets Not Yet Being Recovered [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		6.7	15.4
Other Regulatory Assets Not Yet Being Recovered [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		1.4	0.2
Other Regulatory Assets Not Yet Being Recovered [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		0	0.6
Other Regulatory Assets Not Yet Being Recovered [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		0.1	3.3
Other Regulatory Assets Not Yet Being Recovered [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		0.1	1
Other Regulatory Assets Not Yet Being Recovered [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		0	0.5
Other Regulatory Assets Not Yet Being Recovered [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		2.7	3.6
Asset Retirement Obligation Related to Retired Plants [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 87.4	64.3
Regulatory Asset, Amortization Period		21 years
Asset Retirement Obligation Related to Retired Plants [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 30.1	35.3
Asset Retirement Obligation Related to Retired Plants [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		30.1	35.3
Asset Retirement Obligation Related to Retired Plants [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 28.8	21.6
Regulatory Asset, Amortization Period		23 years
Vegetation Management [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 29.4	0
Vegetation Management [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		29.4	0
Vegetation Management [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 43.6	26.6
Regulatory Asset, Amortization Period		2 years
Vegetation Management [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 43.6	26.6
Regulatory Asset, Amortization Period		2 years
Cook Plant Study Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 7.6	0
Cook Plant Study Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		7.6	0
Storm Related Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 21.3	31.1
Regulatory Asset, Amortization Period		3 years
Storm Related Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 21.3	31.1
Regulatory Asset, Amortization Period		3 years
Storm Related Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 7.2	152.4
Storm Related Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		0	152.4
Storm Related Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		7.2	0
Asset Retirement Obligation - Louisiana [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		7.2	5.3
Asset Retirement Obligation - Louisiana [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		7.2	5.3
Meter Replacement Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 65.4	74.4
Regulatory Asset, Amortization Period		8 years
Meter Replacement Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 35.2	40.1
Regulatory Asset, Amortization Period		8 years
Meter Replacement Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 30.2	34.3
Regulatory Asset, Amortization Period		8 years
Environmental Controls Projects [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 41	43.4
Regulatory Asset, Amortization Period		21 years
Environmental Controls Projects [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 27.8	29.2
Regulatory Asset, Amortization Period		21 years
Environmental Controls Projects [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 13.2	14.2
Regulatory Asset, Amortization Period		13 years
Cook Plant Uprate Project [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 32.6	35
Regulatory Asset, Amortization Period		14 years
Cook Plant Uprate Project [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 32.6	35
Regulatory Asset, Amortization Period		14 years
Distribution Decoupling [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 31.4	12.3
Regulatory Asset, Amortization Period		2 years
Distribution Decoupling [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 31.4	12.3
Regulatory Asset, Amortization Period		2 years
Over-Recovery of Costs Related to Advanced Metering [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 26.5	45.3
Regulatory Asset, Amortization Period		2 years
Over-Recovery of Costs Related to Advanced Metering [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 26.5	45.3
Regulatory Asset, Amortization Period		2 years
Mitchell Plant Transfer [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 16.2	17
Regulatory Asset, Amortization Period		21 years
Michigan Deferred Cook Plant Life Cycle Management Project Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 15.1	16.1
Regulatory Asset, Amortization Period		15 years
Michigan Deferred Cook Plant Life Cycle Management Project Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 15.1	16.1
Regulatory Asset, Amortization Period		15 years
Cook Plant Turbine [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 13.4	15.8
Regulatory Asset, Amortization Period		19 years
Cook Plant Turbine [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 13.4	15.8
Regulatory Asset, Amortization Period		19 years
Ohio Capacity Deferral [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 0	57.8
Ohio Capacity Deferral [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		0	57.8
Other Regulatory Assets Being Recovered [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		48.4	46.1
Other Regulatory Assets Being Recovered [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		0.5	1.2
Other Regulatory Assets Being Recovered [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		4.8	2.4
Other Regulatory Assets Being Recovered [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		0	0.9
Other Regulatory Assets Being Recovered [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		0.6	0.5
Other Regulatory Assets Being Recovered [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		8.9	7.2
Other Regulatory Assets Being Recovered [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		122.8	94.3
Other Regulatory Assets Being Recovered [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		9.7	9.1
Other Regulatory Assets Being Recovered [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		9.3	8.3
Other Regulatory Assets Being Recovered [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		22.3	22.8
Other Regulatory Assets Being Recovered [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		11.9	11.3
Other Regulatory Assets Being Recovered [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		5.4	11
Other Regulatory Assets Being Recovered [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		7.9	11.3
Loss on Reacquired Debt [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 129	134.2
Regulatory Asset, Amortization Period		29 years
Loss on Reacquired Debt [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 6.4	6
Regulatory Asset, Amortization Period		18 years
Loss on Reacquired Debt [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 85.5	89.3
Regulatory Asset, Amortization Period		23 years
Loss on Reacquired Debt [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 17.2	18.7
Regulatory Asset, Amortization Period		29 years
Loss on Reacquired Debt [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 5.3	6.5
Regulatory Asset, Amortization Period		19 years
Loss on Reacquired Debt [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 6.5	4.3
Regulatory Asset, Amortization Period		15 years
Loss on Reacquired Debt [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 6.6	7.4
Regulatory Asset, Amortization Period		24 years
Unrealized Loss on Forward Commitments [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 106.8	104.6
Regulatory Asset, Amortization Period		13 years
Unrealized Loss on Forward Commitments [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 103.6	100.2
Regulatory Asset, Amortization Period		13 years
Cook Nuclear Plant Refueling Outage Levelization [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 63.8	37.5
Regulatory Asset, Amortization Period		3 years
Cook Nuclear Plant Refueling Outage Levelization [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 63.8	37.5
Regulatory Asset, Amortization Period		3 years
Postemployment Benefits [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 34.2	35.6
Regulatory Asset, Amortization Period		4 years
Postemployment Benefits [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 15.9	18
Regulatory Asset, Amortization Period		4 years
Postemployment Benefits [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 7.2	6.5
Regulatory Asset, Amortization Period		4 years
Postemployment Benefits [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 7.6	7.9
Regulatory Asset, Amortization Period		4 years
Peak Demand/Energy Efficiency [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Remaining Refund Period		2 years
Peak Demand/Energy Efficiency [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 18.6	31.9
Regulatory Asset, Amortization Period		7 years
Peak Demand/Energy Efficiency [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 19.5	19.7
Regulatory Asset, Amortization Period		7 years
Peak Demand/Energy Efficiency [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 0	6.3
PJM/SPP Annual Formula Rate True Up [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 7.3	22
Regulatory Asset, Amortization Period		2 years
PJM/SPP Annual Formula Rate True Up [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Transmission Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 4.2	12.9
Regulatory Asset, Amortization Period		2 years
PJM Costs and Off-system Sales Margin Sharing [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 17	0
Remaining Refund Period		2 years
PJM Costs and Off-system Sales Margin Sharing [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 0	20.1
PJM Costs and Off-system Sales Margin Sharing [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		0	20.1
Other Regulatory Liabilities Not Yet Being Paid [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		0.2	0.2
Other Regulatory Liabilities Not Yet Being Paid [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		0.2	0.2
Excess ADIT Associated with Certain Depreciable Property [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		3,303	2,925.7
Excess ADIT Associated with Certain Depreciable Property [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		236.5	251.8
Excess ADIT Associated with Certain Depreciable Property [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Transmission Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		535.7	453.4
Excess ADIT Associated with Certain Depreciable Property [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		718.9	453.5
Excess ADIT Associated with Certain Depreciable Property [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		470.9	362
Excess ADIT Associated with Certain Depreciable Property [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		341.6	350.5
Excess ADIT Associated with Certain Depreciable Property [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		405.8	415.2
Excess ADIT Associated with Certain Depreciable Property [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		339.4	370.5
Excess ADIT Associated with Certain Depreciable Property [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		571.8	1,025.3
Excess ADIT Associated with Certain Depreciable Property [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		274.9	277.1
Excess ADIT Associated with Certain Depreciable Property [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | AEP Transmission Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		0	73.9
Excess ADIT Associated with Certain Depreciable Property [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		0	268.2
Excess ADIT Associated with Certain Depreciable Property [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		0	125
Excess ADIT Associated with Certain Depreciable Property [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		297	280.1
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 890.5	864.3
Remaining Refund Period		17 years
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Remaining Refund Period		1 year
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Transmission Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ (35.4)	(28.5)
Remaining Refund Period		9 years
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 210.7	84.5
Remaining Refund Period		9 years
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 184.5	192.6
Remaining Refund Period		5 years
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 252.3	279.1
Remaining Refund Period		9 years
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 96.3	126.4
Remaining Refund Period		5 years
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 27.8	54.3
Remaining Refund Period		1 year
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 291	695
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		87.1	141.4
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | AEP Transmission Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		0	4.5
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		0	283.7
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		0	40.6
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		22.7	26.9
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | AEPTHCo's investment in ETT and Transource Energy [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		172	172
Asset Removal Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		2,876.7	2,742.8
Asset Removal Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		689.6	645.2
Asset Removal Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Transmission Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		141	99.5
Asset Removal Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		635.3	618.3
Asset Removal Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		166.7	182.5
Asset Removal Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		446.3	436.6
Asset Removal Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		286.8	276.8
Asset Removal Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		453.4	437.8
Basic Transmission Cost Rider [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 37.2	68.8
Remaining Refund Period		2 years
Basic Transmission Cost Rider [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 37.2	68.8
Remaining Refund Period		2 years
Excess Earnings [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 8.3	8.9
Remaining Refund Period		34 years
Excess Earnings [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 5.8	6.3
Deferred Investment Tax Credits [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 215.3	204.9
Remaining Refund Period		43 years
Deferred Investment Tax Credits [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 9.6	10.8
Remaining Refund Period		43 years
Deferred Investment Tax Credits [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 25.8	29.4
Remaining Refund Period		20 years
Deferred Investment Tax Credits [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 51.5	51.5
Remaining Refund Period		25 years
Deferred Investment Tax Credits [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 3.1	4.5
Remaining Refund Period		12 years
Deferred Investment Tax Credits [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 6.2	8.7
Remaining Refund Period		41 years
Deferred Investment Tax Credits [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 0.5	1
Remaining Refund Period		41 years
Other Regulatory Liabilities Being Paid [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 70	73.5
Other Regulatory Liabilities Being Paid [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		4.8	0
Other Regulatory Liabilities Being Paid [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		3.3	3.9
Other Regulatory Liabilities Being Paid [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		24.9	24
Other Regulatory Liabilities Being Paid [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		2.9	11.3
Other Regulatory Liabilities Being Paid [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		4.7	2.5
Other Regulatory Liabilities Being Paid [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1.7	2.4
Other Regulatory Liabilities Being Paid [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		6.1	8.9
Other Regulatory Liabilities Being Paid [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		0.3	0
Other Regulatory Liabilities Being Paid [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1.3	0.4
Other Regulatory Liabilities Being Paid [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		2.8	2.5
Excess Nuclear Decommissioning Funding [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1,236	828.5
Excess Nuclear Decommissioning Funding [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1,236	828.5
PJM Transmission Enhancement Refund [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 67.3	164.2
Remaining Refund Period		6 years
PJM Transmission Enhancement Refund [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 19.5	47.7
Remaining Refund Period		6 years
PJM Transmission Enhancement Refund [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 11.8	29.1
Remaining Refund Period		6 years
PJM Transmission Enhancement Refund [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 29.4	71.3
Remaining Refund Period		6 years
Transition and Restoration Charges - Texas [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 50.5	46
Remaining Refund Period		10 years
Transition and Restoration Charges - Texas [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 50.5	46
Remaining Refund Period		10 years
Spent Nuclear Fuel Liability [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 43.6	42.9
Spent Nuclear Fuel Liability [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		43.6	42.9
Enhanced Service Reliability Plan [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 29.7	43.1
Remaining Refund Period		2 years
Enhanced Service Reliability Plan [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 29.7	43.1
Remaining Refund Period		2 years
Transmission Rate Adjustment Clause [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 28.1	11.3
Remaining Refund Period		2 years
Transmission Rate Adjustment Clause [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 28.1	11.3
Remaining Refund Period		2 years
Deferred Gain on Sale of Rockport Unit 2 [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 27.2	0
Remaining Refund Period		3 years
Deferred Gain on Sale of Rockport Unit 2 [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 10.9	0
Remaining Refund Period		3 years
Energy Efficiency/Peak Demand Reduction [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 23	17.5
Remaining Refund Period		2 years
Energy Efficiency/Peak Demand Reduction [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 19.7	14.9
Remaining Refund Period		2 years
Energy Efficiency/Peak Demand Reduction [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 6	2.5
Unrealized Gain on Forward Commitments [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 17.7	45.9
Remaining Refund Period		5 years
Unrealized Gain on Forward Commitments [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 9.3	34.7
Remaining Refund Period		5 years
Income Taxes Subject to Flow Through [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ (1,341.8)	(1,286.1)
Remaining Refund Period		56 years
Income Taxes Subject to Flow Through [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ (46.2)	(42.8)
Remaining Refund Period		13 years
Income Taxes Subject to Flow Through [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Transmission Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ (100.4)	(81.5)
Remaining Refund Period		44 years
Income Taxes Subject to Flow Through [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ (362.3)	(365.9)
Remaining Refund Period		23 years
Income Taxes Subject to Flow Through [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ (301)	(282.1)
Remaining Refund Period		19 years
Income Taxes Subject to Flow Through [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ (69.7)	(62.8)
Remaining Refund Period		28 years
Income Taxes Subject to Flow Through [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ (7.9)	(7.7)
Remaining Refund Period		24 years
Income Taxes Subject to Flow Through [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ (261.6)	(258.5)
Remaining Refund Period		28 years
Texas Storm Cost Securitization [Member]
Effects of Regulation Textuals [Abstract]
Secured Debt		$ 235
Texas Storm Cost Securitization [Member] | AEP Texas Inc. [Member]
Effects of Regulation Textuals [Abstract]
Secured Debt		$ 235
Excess Earnings - Texas [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Remaining Refund Period		12 years
Advanced Metering Infrastructure Surcharge [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 4.3	8.5
Remaining Refund Period		1 year
Materials and Supplies Related to Retired Plants [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 0.5	9
Virginia Generation Rate Adjustment Clause [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 5.1	10.3
Regulatory Asset, Amortization Period		2 years
Virginia Jurisdictional AMR Meters [Member]
Regulated Generating Unit to be Retired
Total Property, Plant and Equipment, Net		$ 51
Virginia Jurisdictional AMR Meters [Member] | Appalachian Power Co [Member]
Regulated Generating Unit to be Retired
Total Property, Plant and Equipment, Net		51
Over-Recovered Customer Rate Relief - West Virginia [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 5.4	8.8
Remaining Refund Period		1 year
Rate Case Expense - Texas [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 1	4.9
Rockport Plant Dry Sorbent Injection System - Indiana [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 10.2	11.5
Regulatory Asset, Amortization Period		8 years
Cook Plant, Unit 2 Baffle Bolts - Indiana [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 5.4	5.7
Regulatory Asset, Amortization Period		19 years
Smart Grid Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 13.7	8.1
Regulatory Asset, Amortization Period		2 years
Distribution Investment Rider [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 0	7.8
Distribution Investment Rider [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 10.9	0
Regulatory Asset, Amortization Period		2 years
Red Rock Generating Facility [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 8.4	8.6
Regulatory Asset, Amortization Period		37 years
Rate Case Expense - Arkansas [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 5.2	0.8
Regulatory Asset, Amortization Period		5 years
Other Postretirement Benefit Plans [Member] | Pension Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 1,309.8	1,326.6
Regulatory Asset, Amortization Period		11 years
Other Postretirement Benefit Plans [Member] | Pension Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 172	176.9
Regulatory Asset, Amortization Period		11 years
Other Postretirement Benefit Plans [Member] | Pension Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 160.8	172.2
Regulatory Asset, Amortization Period		11 years
Other Postretirement Benefit Plans [Member] | Pension Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 67.5	84.9
Regulatory Asset, Amortization Period		11 years
Other Postretirement Benefit Plans [Member] | Pension Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 167.3	181.5
Regulatory Asset, Amortization Period		11 years
Other Postretirement Benefit Plans [Member] | Pension Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 73.4	84.3
Regulatory Asset, Amortization Period		11 years
Other Postretirement Benefit Plans [Member] | Pension Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 102.6	108.4
Regulatory Asset, Amortization Period		11 years
Other Postretirement Benefit Plans [Member] | Medicare Subsidy [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 23.2	$ 27.9
Regulatory Asset, Amortization Period		5 years
2019 Texas Base Rate Case [Member]
Effects of Regulation Textuals [Abstract]
Asset Impairments and Other Related Charges		$ 33
2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member]
Effects of Regulation Textuals [Abstract]
Asset Impairments and Other Related Charges		33
2019 Texas Base Rate Case [Member] | Vegetation Management [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		26
2019 Texas Base Rate Case [Member] | Vegetation Management [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		26
2019 Texas Base Rate Case [Member] | Excess ADIT Associated with Certain Depreciable Property [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		275
2019 Texas Base Rate Case [Member] | Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		71
2019 Texas Base Rate Case [Member] | Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 71
[1]	(a) In October 2018, PSO changed depreciation rates to utilize the 2020 end-of-life and defer depreciation expense to a regulatory asset for the amount in excess of the previously OCC-approved depreciation rates for Oklaunion Power Station. See “2018 Oklahoma Base Rate Case” section of Note 4 for additional information.
[2]	Beginning in January 2020, SWEPCo began recording a regulatory asset for accelerated depreciation.

Commitments, Guarantees and C_3

Commitments, Guarantees and Contingencies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Contractual Commitments
Less than 1 year	$ 1,274.8
For 2-3 years	1,458.2
For 4-5 years	507.9
After 5 years	1,191.4
Total Contractual Commitments	4,432.3
Commitments, Guarantees and Contingencies (Textuals)
Revolving Credit Facilities	4,000
Disposal, Assessed Fees and Related Interest	279.8	$ 273.6
Payments for Environmental Liabilities	7.5
Letters of Credit [Member]
Maximum Future Payments for Letters of Credit Under Uncommitted Facilities
Maximum Future Payments for Letters of Credit Issued Under the Uncommitted Facility	206.8
Commitments, Guarantees and Contingencies (Textuals)
Letters of Credit Limit	1,200
Uncommitted Facility	405
Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	1,047
For 2-3 years	1,105
For 4-5 years	234.4
After 5 years	111.4
Total Contractual Commitments	2,497.8
Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	227.8
For 2-3 years	353.2
For 4-5 years	273.5
After 5 years	1,080
Total Contractual Commitments	1,934.5
AEP Texas Inc. [Member] | Letters of Credit [Member]
Maximum Future Payments for Letters of Credit Under Uncommitted Facilities
Maximum Future Payments for Letters of Credit Issued Under the Uncommitted Facility	2.2
Appalachian Power Co [Member]
Contractual Commitments
Less than 1 year	450.7
For 2-3 years	441.3
For 4-5 years	78.3
After 5 years	275.8
Total Contractual Commitments	1,246.1
Appalachian Power Co [Member] | Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	415.3
For 2-3 years	369.2
For 4-5 years	4.6
After 5 years	0.3
Total Contractual Commitments	789.4
Appalachian Power Co [Member] | Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	35.4
For 2-3 years	72.1
For 4-5 years	73.7
After 5 years	275.5
Total Contractual Commitments	456.7
Indiana Michigan Power Co [Member]
Contractual Commitments
Less than 1 year	450.8
For 2-3 years	681.2
For 4-5 years	272
After 5 years	356.4
Total Contractual Commitments	1,760.4
Commitments, Guarantees and Contingencies (Textuals)
Disposal, Assessed Fees and Related Interest	279.8	273.6
Payments for Environmental Liabilities	7.5
Indiana Michigan Power Co [Member] | Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	299.8
For 2-3 years	340.7
For 4-5 years	211.6
After 5 years	67.2
Total Contractual Commitments	919.3
Indiana Michigan Power Co [Member] | Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	151
For 2-3 years	340.5
For 4-5 years	60.4
After 5 years	289.2
Total Contractual Commitments	841.1
Ohio Power Co [Member] | Letters of Credit [Member]
Maximum Future Payments for Letters of Credit Under Uncommitted Facilities
Maximum Future Payments for Letters of Credit Issued Under the Uncommitted Facility	1.6
Ohio Power Co [Member] | Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	29
For 2-3 years	58.6
For 4-5 years	58.8
After 5 years	302.5
Total Contractual Commitments	448.9
Public Service Co Of Oklahoma [Member]
Contractual Commitments
Less than 1 year	145.3
For 2-3 years	175.1
For 4-5 years	65.2
After 5 years	193.3
Total Contractual Commitments	578.9
Public Service Co Of Oklahoma [Member] | Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	52.3
For 2-3 years	42.8
For 4-5 years	0
After 5 years	0
Total Contractual Commitments	95.1
Public Service Co Of Oklahoma [Member] | Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	93
For 2-3 years	132.3
For 4-5 years	65.2
After 5 years	193.3
Total Contractual Commitments	483.8
Southwestern Electric Power Co [Member]
Contractual Commitments
Less than 1 year	144.4
For 2-3 years	159.9
For 4-5 years	12.9
After 5 years	8.4
Total Contractual Commitments	325.6
Southwestern Electric Power Co [Member] | Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	130.4
For 2-3 years	147.4
For 4-5 years	4.5
After 5 years	0
Total Contractual Commitments	282.3
Southwestern Electric Power Co [Member] | Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	14
For 2-3 years	12.5
For 4-5 years	8.4
After 5 years	8.4
Total Contractual Commitments	43.3
Decommissioning and Low Level Waste Accumulation Disposal [Member]
Commitments, Guarantees and Contingencies (Textuals)
Cost of Decommissioning and Disposal of Radioactive Waste	2,000
Additional Ongoing Costs for Post Decommissioning Storage of SNF	6
Subsequent Decommissioning of the Spent Fuel Storage Facility	37
Amount Recovered in Rates for Decommissioning Costs	7	8	$ 9
Decommissioning Fund Investments, Fair Value	2,700	2,200
Decommissioning and Low Level Waste Accumulation Disposal [Member] | Indiana Michigan Power Co [Member]
Commitments, Guarantees and Contingencies (Textuals)
Cost of Decommissioning and Disposal of Radioactive Waste	2,000
Additional Ongoing Costs for Post Decommissioning Storage of SNF	6
Subsequent Decommissioning of the Spent Fuel Storage Facility	37
Amount Recovered in Rates for Decommissioning Costs	7	8	9
Decommissioning Fund Investments, Fair Value	2,700	2,200
Spent Nuclear Fuel Disposal [Member]
Commitments, Guarantees and Contingencies (Textuals)
DOE SNF Disposal Fee	0
Disposal, Assessed Fees and Related Interest	280	274
Trust Fund Assets One Time Fee Obligation for Nuclear Fuel Disposition	323	317
Recovery of Spent Nuclear Fuel Storage Costs	8	11	22
Current Amount Recoverable from the Federal Government	24	8
Noncurrent Amount Recoverable from the Federal Government	1	23
Spent Nuclear Fuel Disposal [Member] | Indiana Michigan Power Co [Member]
Commitments, Guarantees and Contingencies (Textuals)
DOE SNF Disposal Fee	0
Disposal, Assessed Fees and Related Interest	280	274
Trust Fund Assets One Time Fee Obligation for Nuclear Fuel Disposition	323	317
Recovery of Spent Nuclear Fuel Storage Costs	8	11	$ 22
Current Amount Recoverable from the Federal Government	24	8
Noncurrent Amount Recoverable from the Federal Government	1	$ 23
Nuclear Incident Liability [Member]
Commitments, Guarantees and Contingencies (Textuals)
Insurance Coverage for Property Damage, Decommissioning and Decontamination	2,700
Coverage for Property Damage, Decommissioning and Decontamination for a Nonnuclear Incident	1,000
Contingent Financial Obligation for Mutual Insurance	47
Insurance Protection for Public Liability Arising from a Nuclear Incident	13,900
Commercially Available Insurance	450
Assessed Amount per Nuclear Incident	275
Deferred Premium Assessment Annual Payment	41
Commercially Available Insurance for Catastrophic Nature	450
Liability Coverage Under the Price-Anderson Act	13,500
Nuclear Incident Liability [Member] | Indiana Michigan Power Co [Member]
Commitments, Guarantees and Contingencies (Textuals)
Insurance Coverage for Property Damage, Decommissioning and Decontamination	2,700
Coverage for Property Damage, Decommissioning and Decontamination for a Nonnuclear Incident	1,000
Contingent Financial Obligation for Mutual Insurance	47
Insurance Protection for Public Liability Arising from a Nuclear Incident	13,900
Commercially Available Insurance	450
Assessed Amount per Nuclear Incident	275
Deferred Premium Assessment Annual Payment	41
Commercially Available Insurance for Catastrophic Nature	450
Liability Coverage Under the Price-Anderson Act	13,500
June 2022 [Member] | Letters of Credit [Member]
Commitments, Guarantees and Contingencies (Textuals)
Revolving Credit Facilities	$ 4,000

Dispositions, Assets and Liab_3

Dispositions, Assets and Liabilities Held for Sale and Impairments (Details)	3 Months Ended						6 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2019USD ($)	Jun. 30, 2019USD ($)MW	Sep. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Mar. 31, 2017USD ($)MW	Jun. 30, 2019USD ($)MW	Sep. 30, 2019USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Jun. 30, 2019Rate	Dec. 31, 2016
Noncash Contribution of Assets by Noncontrolling Interest									$ 0	$ 84,000,000	$ 0
Noncash or Part Noncash Acquisition, Value of Liabilities Assumed									32,400,000	0	0
Dispositions, Assets and Liabilities Held for Sale and Impairments (Textuals)
Make Whole Premium on Extinguishment of Long-term Debt									5,000,000	13,500,000	46,100,000
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges									156,400,000	70,600,000	87,100,000
Asset Impairment Charges
Utilities Operating Expense, Operations									2,743,700,000	2,979,200,000	2,525,200,000
Plant Retirement Costs - Unrecovered Plant [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges									93,000,000
Vertically Integrated Utilities [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges									92,900,000	3,400,000	33,600,000
Vertically Integrated Utilities [Member] | Welsh Plant Unit 2 [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges											19,000,000
Vertically Integrated Utilities [Member] | Turk Generating Plant [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges											15,000,000
Generation and Marketing [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges									31,000,000	47,700,000	53,500,000
Generation and Marketing [Member] | Gavin, Waterford, Darby and Lawrenceburg Plants [Member]
Competitive generation assets sold to a nonaffiliated party (in MWs). | MW						5,329
Cash Proceeds from Sales of Assets, Investing Activities											2,200,000,000
Cash Proceeds from Disposition of Plant, Net											1,200,000,000
Pre-tax Gain on Sale of Plants											226,000,000
Transmission and Distribution Companies [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges									$ 32,500,000	0	0
AEP Texas Inc. [Member]
Jointly Owned Utility Plant, Proportionate Ownership Share	54.69%								54.69%
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges									$ 32,500,000	0	0
Asset Impairment Charges
Utilities Operating Expense, Operations									492,000,000	488,900,000	453,100,000
AEP Transmission Co [Member]
Asset Impairment Charges
Utilities Operating Expense, Operations									93,900,000	83,800,000	60,100,000
Appalachian Power Co [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges									92,900,000	0	0
Asset Impairment Charges
Utilities Operating Expense, Operations									567,600,000	511,600,000	503,100,000
Appalachian Power Co [Member] | Plant Retirement Costs - Unrecovered Plant [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges									93,000,000
Indiana Michigan Power Co [Member]
Cost of Purchased Power from Affiliate									214,900,000	237,900,000	223,900,000
Asset Impairment Charges
Utilities Operating Expense, Operations									641,200,000	585,400,000	591,300,000
Ohio Power Co [Member]
Cost of Purchased Power from Affiliate									156,000,000	135,300,000	108,500,000
Asset Impairment Charges
Utilities Operating Expense, Operations									742,600,000	771,300,000	516,000,000
Public Service Co Of Oklahoma [Member]
Dispositions, Assets and Liabilities Held for Sale and Impairments (Textuals)
Make Whole Premium on Extinguishment of Long-term Debt									3,000,000	0	0
Asset Impairment Charges
Utilities Operating Expense, Operations									315,000,000	372,800,000	315,100,000
Southwestern Electric Power Co [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges									0	0	33,600,000
Asset Impairment Charges
Utilities Operating Expense, Operations									348,000,000	$ 384,200,000	318,300,000
Conesville Generating Station (Unit No. 4) [Member] | Generation and Marketing [Member]
Asset Impairment Charges
Fair Value of Impaired Assets	$ 0								$ 0
Utilities Operating Expense, Operations	$ 31,000,000
Other Assets [Member] | Corporate and Other [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges				$ 21,000,000
Merchant Coal-Fired Generation Assets [Member] | Generation and Marketing [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges						$ 4,000,000
Zimmer Plant Assets [Member] | Generation and Marketing [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges						$ 7,000,000
Racine Hydroelectric Plant [Member] | Generation and Marketing [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges			$ 35,000,000		$ 43,000,000
Asset Impairment Charges
Fair Value of Impaired Assets			$ 0		$ 0						0
Conesville Generating Station (Unit No. 4) [Member] | Coal [Member]
Jointly Owned Utility Plant, Proportionate Ownership Share	83.50%								83.50%	83.50%			43.50%
J.M. Stuart Generating Station [Member] | Coal [Member]
Jointly Owned Utility Plant, Proportionate Ownership Share													26.00%
Wm. H. Zimmer Generating Station [Member] | Coal [Member]
Jointly Owned Utility Plant, Proportionate Ownership Share													25.40%
Wm. H. Zimmer Generating Station [Member] | Coal [Member] | Generation and Marketing [Member]
Jointly Owned Utility Plant, Proportionate Ownership Share													25.40%
Oklaunion Generating Station (Unit No. 1) [Member] | AEP Texas Inc. [Member]
Jointly Owned Utility Plant, Proportionate Ownership Share	54.70%								54.70%
Oklaunion Generating Station (Unit No. 1) [Member] | Public Service Co Of Oklahoma [Member]
Jointly Owned Utility Plant, Proportionate Ownership Share	15.60%								15.60%
Oklaunion Generating Station (Unit No. 1) [Member] | Coal [Member]
Jointly Owned Utility Plant, Proportionate Ownership Share	70.30%								70.30%	70.30%
Oklaunion Generating Station (Unit No. 1) [Member] | Coal [Member] | AEP Texas Inc. [Member]
Jointly Owned Utility Plant, Proportionate Ownership Share	54.70%								54.70%	54.70%			54.70%
Oklaunion Generating Station (Unit No. 1) [Member] | Coal [Member] | Public Service Co Of Oklahoma [Member]
Jointly Owned Utility Plant, Proportionate Ownership Share	15.60%								15.60%	15.60%
AEP Wind Holdings LLC [Member]
Noncash or Part Noncash Acquisition, Other Assets Acquired									$ 134,800,000
WindGenerationMWs | MW		724
AEP Wind Holdings LLC [Member] | Generation and Marketing [Member]
Percentage of an Asset Acquired		75.00%					75.00%					50.00%
WindGenerationMWs | MW		724
Noncash or Part Noncash Acquisition, Value of Assets Acquired		$ 1,100,000,000
Asset Impairment Charges
Noncash or Part Noncash Acquisition, Debt Assumed							$ 364,000,000
Payments to Acquire Businesses, Gross							$ 580,400,000
Maximum Potential Amount of Future Payments Associated with Guarantee	$ 175,000,000								175,000,000
Guarantor Obligations, Current Carrying Value	$ 34,000,000								34,000,000
AEP Wind Holdings LLC [Member] | Indiana Michigan Power Co [Member] | Generation and Marketing [Member]
Cost of Purchased Power from Affiliate									9,000,000
AEP Wind Holdings LLC [Member] | Ohio Power Co [Member] | Generation and Marketing [Member]
Cost of Purchased Power from Affiliate									17,000,000
AEP Wind Holdings LLC [Member] | Southwestern Electric Power Co [Member] | Generation and Marketing [Member]
Cost of Purchased Power from Affiliate									10,000,000
Santa Rita East [Member]
Noncash or Part Noncash Acquisition, Other Assets Acquired									118,800,000
Santa Rita East [Member] | Generation and Marketing [Member]
WindGenerationMWs | MW							227
Asset Impairment Charges
Payments to Acquire Businesses, Gross								$ 356,000,000
Current Liabilities [Member] | AEP Wind Holdings LLC [Member] | Generation and Marketing [Member]
Noncash or Part Noncash Acquisition, Value of Liabilities Assumed							$ 12,900,000
Current Assets [Member] | AEP Wind Holdings LLC [Member] | Generation and Marketing [Member]
Noncash or Part Noncash Acquisition, Other Assets Acquired							8,800,000
Property, Plant and Equipment [Member] | AEP Wind Holdings LLC [Member] | Generation and Marketing [Member]
Noncash or Part Noncash Acquisition, Other Assets Acquired							238,100,000
Asset Retirement Obligation [Member] | AEP Wind Holdings LLC [Member] | Generation and Marketing [Member]
Noncash or Part Noncash Acquisition, Value of Liabilities Assumed							5,700,000
Equity Method Investments [Member] | AEP Wind Holdings LLC [Member] | Generation and Marketing [Member]
Noncash or Part Noncash Acquisition, Other Assets Acquired							404,000,000
Liabilities, Total [Member] | AEP Wind Holdings LLC [Member] | Generation and Marketing [Member]
Noncash or Part Noncash Acquisition, Value of Liabilities Assumed							18,600,000
Other Noncurrent Assets [Member] | AEP Wind Holdings LLC [Member] | Generation and Marketing [Member]
Noncash or Part Noncash Acquisition, Other Assets Acquired							82,900,000
Noncontrolling Interest [Member]
Noncash Contribution of Assets by Noncontrolling Interest									253,400,000	$ 0	$ 0
Noncontrolling Interest [Member] | AEP Wind Holdings LLC [Member] | Generation and Marketing [Member]
Noncash Contribution of Assets by Noncontrolling Interest							134,800,000
Total Assets [Member] | AEP Wind Holdings LLC [Member] | Generation and Marketing [Member]
Noncash or Part Noncash Acquisition, Other Assets Acquired							733,800,000
Total Liabilities And Equity [Member] | AEP Wind Holdings LLC [Member] | Generation and Marketing [Member]
Noncash or Part Noncash Acquisition, Value of Liabilities Assumed							$ 153,400,000
2019 Texas Base Rate Case [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges									33,000,000
2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges									33,000,000
2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member] | Transmission and Distribution Companies [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges									33,000,000
Virginia Legislation Affecting Earnings Reviews [Member] | Plant Retirement Costs - Unrecovered Plant [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges									93,000,000
Virginia Legislation Affecting Earnings Reviews [Member] | Appalachian Power Co [Member] | Plant Retirement Costs - Unrecovered Plant [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges									93,000,000
Virginia Legislation Affecting Earnings Reviews [Member] | Appalachian Power Co [Member] | Vertically Integrated Utilities [Member] | Plant Retirement Costs - Unrecovered Plant [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges									$ 93,000,000

Benefit Plans 1 (Details)

Benefit Plans 1 (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs	$ 3,407.3	$ 2,577.4
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability	(719.8)	(782.6)
AEP Texas Inc. [Member]
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs	147.1	56.3
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability	(81.1)	(104)
Appalachian Power Co [Member]
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs	215.3	188.1
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability	(55.2)	(58.6)
Indiana Michigan Power Co [Member]
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs	181.9	193
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability	(67.8)	(87.8)
Ohio Power Co [Member]
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs	546.3	441
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability	(42.7)	(43.8)
Public Service Co Of Oklahoma [Member]
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs	4.1	7.1
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability	(18.4)	(32.5)
Southwestern Electric Power Co [Member]
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs	160.5	111.2
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability	$ (86.2)	$ (102)
Pension Plans [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate	3.25%	4.30%
Interest Crediting Rate	4.00%	4.00%
Rate of Compensation Increase	4.95%	4.85%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate	4.30%	3.65%	4.05%
Interest Crediting Rate	4.00%	4.00%	4.00%
Expected Return on Plan Assets	6.25%	6.00%	6.00%
Rate of Compensation Increase	4.95%	4.85%	4.80%
Change in Benefit Obligation
Benefit Obligation as of January 1	$ 4,810.3	$ 5,215.8
Service Cost	95.5	97.6	$ 96.5
Interest Cost	204.4	187.8	203.1
Actuarial (Gain) Loss	493.6	(306.3)
Plan Amendments	0.2	0
Benefit Payments	(367.2)	(384.6)
Participant Contributions	0	0
Medicare Subsidy	0	0
Benefit Obligation as of December 31	5,236.8	4,810.3	5,215.8
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	4,695.9	5,174.1
Actual Gain (Loss) on Plan Assets	681.1	(104.9)
Company Contributions	5.6	11.3
Participant Contributions	0	0
Benefit Payments	(367.2)	(384.6)
Fair Value of Plan Assets as of December 31	5,015.4	4,695.9	$ 5,174.1
Funded (Underfunded) Status as of December 31	(221.4)	(114.4)
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs	0	0
Other Current Liabilities - Accrued Short-term Benefit Liability	(6.1)	(5.7)
Employee Benefits and Pension Obligations - Accrued Long-term Benefit Liability	(215.3)	(108.7)
Funded (Underfunded) Status	(221.4)	(114.4)
Components
Net Actuarial Loss	1,406.2	1,355.2
Prior Service Cost (Credit)	0.2	0
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year	108.6	88.8
Amortization of Actuarial Gain (Loss)	(57.6)	(87.8)
Prior Service (Credit) Cost	0.2	0
Amortization of Prior Service Credit (Cost)	0	0
Change for the Year	$ 51.2	$ 1
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	4.95%	4.85%
Company Contributions	$ 5.6	$ 11.3
Pension Plans [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	1,351.8	1,267.9
Pension Plans [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	11.5	18.4
Pension Plans [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	$ 43.1	$ 68.9
Pension Plans [Member] | AEP Texas Inc. [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate	3.25%	4.30%
Interest Crediting Rate	4.00%	4.00%
Rate of Compensation Increase	5.00%	4.95%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate	4.30%	3.65%	4.05%
Interest Crediting Rate	4.00%	4.00%	4.00%
Expected Return on Plan Assets	6.25%	6.00%	6.00%
Rate of Compensation Increase	5.00%	4.95%	4.90%
Change in Benefit Obligation
Benefit Obligation as of January 1	$ 409.3	$ 441.3
Service Cost	8.6	9.2	$ 8.6
Interest Cost	17.5	16	17.1
Actuarial (Gain) Loss	40.1	(20.9)
Plan Amendments	0	0
Benefit Payments	(34.3)	(36.3)
Participant Contributions	0	0
Benefit Obligation as of December 31	441.2	409.3	441.3
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	410.7	455.9
Actual Gain (Loss) on Plan Assets	58.3	(9.3)
Company Contributions	0.4	0.4
Participant Contributions	0	0
Benefit Payments	(34.3)	(36.3)
Fair Value of Plan Assets as of December 31	435.1	410.7	$ 455.9
Funded (Underfunded) Status as of December 31	(6.1)	1.4
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs	0	5.2
Other Current Liabilities - Accrued Short-term Benefit Liability	(0.4)	(0.4)
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability	(5.7)	(3.4)
Funded (Underfunded) Status	(6.1)	1.4
Components
Net Actuarial Loss	184.7	182
Prior Service Cost (Credit)	0	0
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year	7.6	14
Amortization of Actuarial Gain (Loss)	(4.9)	(7.2)
Prior Service (Credit) Cost	0	0
Amortization of Prior Service Credit (Cost)	0	0
Change for the Year	$ 2.7	$ 6.8
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	5.00%	4.95%
Company Contributions	$ 0.4	$ 0.4
Pension Plans [Member] | AEP Texas Inc. [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	172.2	168.2
Pension Plans [Member] | AEP Texas Inc. [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	2.7	2.9
Pension Plans [Member] | AEP Texas Inc. [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	$ 9.8	$ 10.9
Pension Plans [Member] | Appalachian Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate	3.25%	4.30%
Interest Crediting Rate	4.00%	4.00%
Rate of Compensation Increase	4.80%	4.75%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate	4.30%	3.65%	4.05%
Interest Crediting Rate	4.00%	4.00%	4.00%
Expected Return on Plan Assets	6.25%	6.00%	6.00%
Rate of Compensation Increase	4.75%	4.75%	4.60%
Change in Benefit Obligation
Benefit Obligation as of January 1	$ 603.1	$ 665
Service Cost	9.4	9.3	$ 9.4
Interest Cost	25.2	23.5	25.7
Actuarial (Gain) Loss	52.9	(49.2)
Plan Amendments	0	0
Benefit Payments	(43.4)	(45.5)
Participant Contributions	0	0
Medicare Subsidy	0	0
Benefit Obligation as of December 31	647.2	603.1	665
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	593.3	651.7
Actual Gain (Loss) on Plan Assets	87.1	(12.9)
Company Contributions	0	0
Participant Contributions	0	0
Benefit Payments	(43.4)	(45.5)
Fair Value of Plan Assets as of December 31	637	593.3	$ 651.7
Funded (Underfunded) Status as of December 31	(10.2)	(9.8)
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs	0	0
Other Current Liabilities - Accrued Short-term Benefit Liability	0	0
Employee Benefits and Pension Obligations - Accrued Long-term Benefit Liability	(10.2)	(9.8)
Funded (Underfunded) Status	(10.2)	(9.8)
Components
Net Actuarial Loss	168.3	172.2
Prior Service Cost (Credit)	0	0
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year	3.1	0.3
Amortization of Actuarial Gain (Loss)	(7)	(10.6)
Prior Service (Credit) Cost	0	0
Amortization of Prior Service Credit (Cost)	0	0
Change for the Year	$ (3.9)	$ (10.3)
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	4.80%	4.75%
Company Contributions	$ 0	$ 0
Pension Plans [Member] | Appalachian Power Co [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	166.3	169.6
Pension Plans [Member] | Appalachian Power Co [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	0.3	0.5
Pension Plans [Member] | Appalachian Power Co [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	$ 1.7	$ 2.1
Pension Plans [Member] | Indiana Michigan Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate	3.25%	4.30%
Interest Crediting Rate	4.00%	4.00%
Rate of Compensation Increase	4.95%	4.90%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate	4.30%	3.65%	4.05%
Interest Crediting Rate	4.00%	4.00%	4.00%
Expected Return on Plan Assets	6.25%	6.00%	6.00%
Rate of Compensation Increase	4.95%	4.90%	4.85%
Change in Benefit Obligation
Benefit Obligation as of January 1	$ 567	$ 624.3
Service Cost	13.4	13.6	$ 14
Interest Cost	23.8	22.1	24.3
Actuarial (Gain) Loss	49.8	(53.9)
Plan Amendments	0	0
Benefit Payments	(37.9)	(39.1)
Participant Contributions	0	0
Medicare Subsidy	0	0
Benefit Obligation as of December 31	616.1	567	624.3
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	583.8	636.7
Actual Gain (Loss) on Plan Assets	84.6	(13.8)
Company Contributions	0	0
Participant Contributions	0	0
Benefit Payments	(37.9)	(39.1)
Fair Value of Plan Assets as of December 31	630.5	583.8	$ 636.7
Funded (Underfunded) Status as of December 31	14.4	16.8
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs	15.8	18
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability	(1.4)	(1.2)
Funded (Underfunded) Status	14.4	16.8
Components
Net Actuarial Loss	76	80.6
Prior Service Cost (Credit)	0	0
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year	2	(4.5)
Amortization of Actuarial Gain (Loss)	(6.6)	(9.8)
Prior Service (Credit) Cost	0	0
Amortization of Prior Service Credit (Cost)	0	0
Change for the Year	$ (4.6)	$ (14.3)
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	4.95%	4.90%
Company Contributions	$ 0	$ 0
Pension Plans [Member] | Indiana Michigan Power Co [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	73.7	78.4
Pension Plans [Member] | Indiana Michigan Power Co [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	0.5	0.5
Pension Plans [Member] | Indiana Michigan Power Co [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	$ 1.8	$ 1.7
Pension Plans [Member] | Ohio Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate	3.25%	4.30%
Interest Crediting Rate	4.00%	4.00%
Rate of Compensation Increase	5.15%	5.00%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate	4.30%	3.65%	4.05%
Interest Crediting Rate	4.00%	4.00%	4.00%
Expected Return on Plan Assets	6.25%	6.00%	6.00%
Rate of Compensation Increase	5.20%	5.00%	4.95%
Change in Benefit Obligation
Benefit Obligation as of January 1	$ 453.9	$ 501.1
Service Cost	7.9	7.7	$ 7.5
Interest Cost	19.1	17.7	19.4
Actuarial (Gain) Loss	40.5	(36.6)
Plan Amendments	0	0
Benefit Payments	(33.6)	(36)
Participant Contributions	0	0
Medicare Subsidy	0	0
Benefit Obligation as of December 31	487.8	453.9	501.1
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	466.1	509.1
Actual Gain (Loss) on Plan Assets	66.6	(7)
Participant Contributions	0	0
Benefit Payments	(33.6)	(36)
Fair Value of Plan Assets as of December 31	499.1	466.1	$ 509.1
Funded (Underfunded) Status as of December 31	11.3	12.2
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs	11.7	12.6
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability	(0.4)	(0.4)
Funded (Underfunded) Status	11.3	12.2
Components
Net Actuarial Loss	178.7	180.7
Prior Service Cost (Credit)	0	0
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year	3.3	(0.9)
Amortization of Actuarial Gain (Loss)	(5.3)	(8)
Prior Service (Credit) Cost	0	0
Amortization of Prior Service Credit (Cost)	0	0
Change for the Year	$ (2)	$ (8.9)
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	5.15%	5.00%
Pension Plans [Member] | Ohio Power Co [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	$ 178.7	$ 180.7
Pension Plans [Member] | Public Service Co Of Oklahoma [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate	3.25%	4.30%
Interest Crediting Rate	4.00%	4.00%
Rate of Compensation Increase	5.05%	4.90%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate	4.30%	3.65%	4.05%
Interest Crediting Rate	4.00%	4.00%	4.00%
Expected Return on Plan Assets	6.25%	6.00%	6.00%
Rate of Compensation Increase	5.05%	4.90%	4.90%
Change in Benefit Obligation
Benefit Obligation as of January 1	$ 253.8	$ 276.6
Service Cost	6.5	7	$ 6.4
Interest Cost	10.6	9.9	10.7
Actuarial (Gain) Loss	16.8	(18.9)
Plan Amendments	0	0
Benefit Payments	(20.2)	(20.8)
Participant Contributions	0	0
Benefit Obligation as of December 31	267.5	253.8	276.6
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	261.2	287.8
Actual Gain (Loss) on Plan Assets	34.7	(5.9)
Company Contributions	0.5	0.1
Participant Contributions	0	0
Benefit Payments	(20.2)	(20.8)
Fair Value of Plan Assets as of December 31	276.2	261.2	$ 287.8
Funded (Underfunded) Status as of December 31	8.7	7.4
Benefit Amounts Recognized on the Balance Sheets
Employee Benefits and Pension Assets - Prepaid Benefit Costs	10.6	9.7
Other Current Liabilities - Accrued Short-term Benefit Liability	(0.1)	(0.2)
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability	(1.8)	(2.1)
Funded (Underfunded) Status	8.7	7.4
Components
Net Actuarial Loss	73	77.6
Prior Service Cost (Credit)	0	0
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year	(1.7)	3.2
Amortization of Actuarial Gain (Loss)	(2.9)	(4.4)
Prior Service (Credit) Cost	0	0
Amortization of Prior Service Credit (Cost)	0	0
Change for the Year	$ (4.6)	$ (1.2)
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	5.05%	4.90%
Company Contributions	$ 0.5	$ 0.1
Pension Plans [Member] | Public Service Co Of Oklahoma [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	$ 73	$ 77.6
Pension Plans [Member] | Southwestern Electric Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate	3.25%	4.30%
Interest Crediting Rate	4.00%	4.00%
Rate of Compensation Increase	4.90%	4.85%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate	4.30%	3.65%	4.05%
Interest Crediting Rate	4.00%	4.00%	4.00%
Expected Return on Plan Assets	6.25%	6.00%	6.00%
Rate of Compensation Increase	4.90%	4.85%	4.80%
Change in Benefit Obligation
Benefit Obligation as of January 1	$ 291.4	$ 314.6
Service Cost	8.6	9.3	$ 8.7
Interest Cost	12.4	11.3	12.3
Actuarial (Gain) Loss	25.5	(19.2)
Plan Amendments	0	0
Benefit Payments	(23.7)	(24.6)
Participant Contributions	0	0
Benefit Obligation as of December 31	314.2	291.4	314.6
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	281	311.7
Actual Gain (Loss) on Plan Assets	39.5	(7.3)
Company Contributions	0.1	1.2
Participant Contributions	0	0
Benefit Payments	(23.7)	(24.6)
Fair Value of Plan Assets as of December 31	296.9	281	$ 311.7
Funded (Underfunded) Status as of December 31	(17.3)	(10.4)
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs	0	0
Other Current Liabilities - Accrued Short-term Benefit Liability	(0.1)	(0.2)
Employee Benefits and Pension Obligations - Accrued Long-term Benefit Liability	(17.2)	(10.2)
Funded (Underfunded) Status	(17.3)	(10.4)
Components
Net Actuarial Loss	97.8	97.4
Prior Service Cost (Credit)	0	0
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year	3.8	5.5
Amortization of Actuarial Gain (Loss)	(3.4)	(5.5)
Prior Service (Credit) Cost	0	0
Amortization of Prior Service Credit (Cost)	0	0
Change for the Year	$ 0.4	$ 0
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	4.90%	4.85%
Company Contributions	$ 0.1	$ 1.2
Pension Plans [Member] | Southwestern Electric Power Co [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	97.8	97.4
Pension Plans [Member] | Southwestern Electric Power Co [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	0	0
Pension Plans [Member] | Southwestern Electric Power Co [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	$ 0	0
Pension Plans [Member] | Minimum [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase	3.00%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	3.00%
Pension Plans [Member] | Minimum [Member] | AEP Texas Inc. [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase	3.00%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	3.00%
Pension Plans [Member] | Minimum [Member] | Appalachian Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase	3.00%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	3.00%
Pension Plans [Member] | Minimum [Member] | Indiana Michigan Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase	3.00%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	3.00%
Pension Plans [Member] | Minimum [Member] | Ohio Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase	3.00%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	3.00%
Pension Plans [Member] | Minimum [Member] | Public Service Co Of Oklahoma [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase	3.00%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	3.00%
Pension Plans [Member] | Minimum [Member] | Southwestern Electric Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase	3.00%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	3.00%
Pension Plans [Member] | Maximum [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase	11.50%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	11.50%
Pension Plans [Member] | Maximum [Member] | AEP Texas Inc. [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase	11.50%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	11.50%
Pension Plans [Member] | Maximum [Member] | Appalachian Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase	11.50%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	11.50%
Pension Plans [Member] | Maximum [Member] | Indiana Michigan Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase	11.50%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	11.50%
Pension Plans [Member] | Maximum [Member] | Ohio Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase	11.50%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	11.50%
Pension Plans [Member] | Maximum [Member] | Public Service Co Of Oklahoma [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase	11.50%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	11.50%
Pension Plans [Member] | Maximum [Member] | Southwestern Electric Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase	11.50%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	11.50%
Nonqualified Pension Plans [Member]
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	$ 0
Company Contributions	6	11
Fair Value of Plan Assets as of December 31	0	0
Benefit Plans (Textuals) [Abstract]
Company Contributions	6	11
Nonqualified Pension Plans [Member] | AEP Texas Inc. [Member]
Change in Benefit Obligation
Benefit Obligation as of January 1	3.8
Benefit Obligation as of December 31		3.8
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	0
Fair Value of Plan Assets as of December 31	0	0
Nonqualified Pension Plans [Member] | Appalachian Power Co [Member]
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	0
Fair Value of Plan Assets as of December 31	0	0
Nonqualified Pension Plans [Member] | Indiana Michigan Power Co [Member]
Change in Benefit Obligation
Benefit Obligation as of January 1	1.2
Benefit Obligation as of December 31	1.5	1.2
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	0
Fair Value of Plan Assets as of December 31	0	0
Nonqualified Pension Plans [Member] | Ohio Power Co [Member]
Change in Benefit Obligation
Benefit Obligation as of January 1	0.4
Benefit Obligation as of December 31	0.4	0.4
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	0
Fair Value of Plan Assets as of December 31	0	0
Nonqualified Pension Plans [Member] | Public Service Co Of Oklahoma [Member]
Change in Benefit Obligation
Benefit Obligation as of January 1	2.3
Benefit Obligation as of December 31	1.9	2.3
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	0
Fair Value of Plan Assets as of December 31	0	0
Nonqualified Pension Plans [Member] | Southwestern Electric Power Co [Member]
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	0
Fair Value of Plan Assets as of December 31	$ 0	$ 0
Other Postretirement Benefit Plans [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate	3.30%	4.30%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate	4.30%	3.60%	4.10%
Expected Return on Plan Assets	6.25%	6.00%	6.75%
Health Care Trend Rates
Initial	6.00%	6.25%
Ultimate	4.50%	5.00%
Year Ultimate Reached	2026	2024
Change in Benefit Obligation
Benefit Obligation as of January 1	$ 1,194.5	$ 1,332
Service Cost	9.5	11.6	$ 11.2
Interest Cost	50.5	47.4	59.3
Actuarial (Gain) Loss	58.8	(100.1)
Plan Amendments	(11)	0
Benefit Payments	(113)	(133.6)
Participant Contributions	35.5	36.5
Medicare Subsidy	0.6	0.7
Benefit Obligation as of December 31	1,225.4	1,194.5	1,332
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	1,534.2	1,732.5
Actual Gain (Loss) on Plan Assets	321	(118.3)
Company Contributions	4.1	17.1
Participant Contributions	35.5	36.5
Benefit Payments	(113)	(133.6)
Fair Value of Plan Assets as of December 31	1,781.8	1,534.2	$ 1,732.5
Funded (Underfunded) Status as of December 31	556.4	339.7
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs	590.8	392.2
Other Current Liabilities - Accrued Short-term Benefit Liability	(2.6)	(2.8)
Employee Benefits and Pension Obligations - Accrued Long-term Benefit Liability	(31.8)	(49.7)
Funded (Underfunded) Status	556.4	339.7
Components
Net Actuarial Loss	225.8	419.8
Prior Service Cost (Credit)	(285.7)	(347.2)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year	(171.9)	120.4
Amortization of Actuarial Gain (Loss)	(22.1)	(10.5)
Prior Service (Credit) Cost	(7.6)	0
Amortization of Prior Service Credit (Cost)	69.1	69.1
Change for the Year	(132.5)	179
Benefit Plans (Textuals) [Abstract]
Company Contributions	4.1	17.1
Other Postretirement Benefit Plans [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	(46.8)	52.5
Other Postretirement Benefit Plans [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	(2.7)	4.2
Other Postretirement Benefit Plans [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	$ (10.4)	$ 15.9
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate	3.30%	4.30%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate	4.30%	3.60%	4.10%
Expected Return on Plan Assets	6.25%	6.00%	6.75%
Health Care Trend Rates
Initial	6.00%	6.25%
Ultimate	4.50%	5.00%
Year Ultimate Reached	2026	2024
Change in Benefit Obligation
Benefit Obligation as of January 1	$ 95.9	$ 107.1
Service Cost	0.8	0.9	$ 0.9
Interest Cost	4	3.8	4.9
Actuarial (Gain) Loss	3.9	(8.3)
Plan Amendments	(0.9)	0
Benefit Payments	(8.8)	(10.7)
Participant Contributions	2.9	3.1
Benefit Obligation as of December 31	97.8	95.9	107.1
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	129.9	147.3
Actual Gain (Loss) on Plan Assets	24	(14.6)
Company Contributions	0.1	4.8
Participant Contributions	2.9	3.1
Benefit Payments	(8.8)	(10.7)
Fair Value of Plan Assets as of December 31	148.1	129.9	$ 147.3
Funded (Underfunded) Status as of December 31	50.3	34
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs	50.3	34
Other Current Liabilities - Accrued Short-term Benefit Liability	0	0
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability	0	0
Funded (Underfunded) Status	50.3	34
Components
Net Actuarial Loss	23.5	38
Prior Service Cost (Credit)	(24.2)	(29.5)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year	(12.7)	14.9
Amortization of Actuarial Gain (Loss)	(1.8)	(0.8)
Prior Service (Credit) Cost	(0.6)	0
Amortization of Prior Service Credit (Cost)	5.9	5.9
Change for the Year	(9.2)	20
Benefit Plans (Textuals) [Abstract]
Company Contributions	0.1	4.8
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	(0.2)	8.7
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	(0.1)	0
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	$ (0.4)	$ (0.2)
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate	3.30%	4.30%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate	4.30%	3.60%	4.10%
Expected Return on Plan Assets	6.25%	6.00%	6.75%
Health Care Trend Rates
Initial	6.00%	6.25%
Ultimate	4.50%	5.00%
Year Ultimate Reached	2026	2024
Change in Benefit Obligation
Benefit Obligation as of January 1	$ 205.5	$ 236.5
Service Cost	1	1.1	$ 1.1
Interest Cost	8.7	8.2	10.6
Actuarial (Gain) Loss	4.7	(21.9)
Plan Amendments	(1.7)	0
Benefit Payments	(20.8)	(24.7)
Participant Contributions	5.9	6.1
Medicare Subsidy	0.2	0.2
Benefit Obligation as of December 31	203.5	205.5	236.5
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	238.4	273.4
Actual Gain (Loss) on Plan Assets	45.3	(18.7)
Company Contributions	2.2	2.3
Participant Contributions	5.9	6.1
Benefit Payments	(20.8)	(24.7)
Fair Value of Plan Assets as of December 31	271	238.4	$ 273.4
Funded (Underfunded) Status as of December 31	67.5	32.9
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs	92	62.3
Other Current Liabilities - Accrued Short-term Benefit Liability	(2)	(2.1)
Employee Benefits and Pension Obligations - Accrued Long-term Benefit Liability	(22.5)	(27.3)
Funded (Underfunded) Status	67.5	32.9
Components
Net Actuarial Loss	28.8	58.9
Prior Service Cost (Credit)	(41.6)	(50.4)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year	(26.4)	12.8
Amortization of Actuarial Gain (Loss)	(3.7)	(1.9)
Prior Service (Credit) Cost	(1.3)	0
Amortization of Prior Service Credit (Cost)	10.1	10
Change for the Year	(21.3)	20.9
Benefit Plans (Textuals) [Abstract]
Company Contributions	2.2	2.3
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	(5.5)	2.6
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	(1.5)	1.2
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	$ (5.8)	$ 4.7
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate	3.30%	4.30%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate	4.30%	3.60%	4.10%
Expected Return on Plan Assets	6.25%	6.00%	6.75%
Health Care Trend Rates
Initial	6.00%	6.25%
Ultimate	4.50%	5.00%
Year Ultimate Reached	2026	2024
Change in Benefit Obligation
Benefit Obligation as of January 1	$ 138.3	$ 153.5
Service Cost	1.4	1.6	$ 1.6
Interest Cost	5.8	5.4	6.9
Actuarial (Gain) Loss	8.1	(10.6)
Plan Amendments	(1.5)	0
Benefit Payments	(13.6)	(16.2)
Participant Contributions	4.4	4.5
Medicare Subsidy	0	0.1
Benefit Obligation as of December 31	142.9	138.3	153.5
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	187.3	211.1
Actual Gain (Loss) on Plan Assets	38.2	(12.1)
Company Contributions	0	0
Participant Contributions	4.4	4.5
Benefit Payments	(13.6)	(16.2)
Fair Value of Plan Assets as of December 31	216.3	187.3	$ 211.1
Funded (Underfunded) Status as of December 31	73.4	49
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs	73.4	49
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability	0	0
Funded (Underfunded) Status	73.4	49
Components
Net Actuarial Loss	32.7	54.7
Prior Service Cost (Credit)	(39)	(47.4)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year	(19.3)	13.9
Amortization of Actuarial Gain (Loss)	(2.7)	(1.2)
Prior Service (Credit) Cost	(1)	0
Amortization of Prior Service Credit (Cost)	9.4	9.5
Change for the Year	(13.6)	22.2
Benefit Plans (Textuals) [Abstract]
Company Contributions	0	0
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	(6.2)	6.5
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	0	0.2
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	$ (0.1)	$ 0.6
Other Postretirement Benefit Plans [Member] | Ohio Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate	3.30%	4.30%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate	4.30%	3.60%	4.10%
Expected Return on Plan Assets	6.25%	6.00%	6.75%
Health Care Trend Rates
Initial	6.00%	6.25%
Ultimate	4.50%	5.00%
Year Ultimate Reached	2026	2024
Change in Benefit Obligation
Benefit Obligation as of January 1	$ 129.5	$ 144.3
Service Cost	0.8	0.9	$ 0.9
Interest Cost	5.5	5.1	6.7
Actuarial (Gain) Loss	4.9	(9.4)
Plan Amendments	(1.2)	0
Benefit Payments	(13.5)	(15.8)
Participant Contributions	4.1	4.3
Medicare Subsidy	0.1	0.1
Benefit Obligation as of December 31	130.2	129.5	144.3
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	175.4	198.5
Actual Gain (Loss) on Plan Assets	31.1	(11.6)
Participant Contributions	4.1	4.3
Benefit Payments	(13.5)	(15.8)
Fair Value of Plan Assets as of December 31	197.1	175.4	$ 198.5
Funded (Underfunded) Status as of December 31	66.9	45.9
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs	66.9	45.9
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability	0	0
Funded (Underfunded) Status	66.9	45.9
Components
Net Actuarial Loss	17.2	35.5
Prior Service Cost (Credit)	(28.6)	(34.7)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year	(15.8)	14
Amortization of Actuarial Gain (Loss)	(2.5)	(1.1)
Prior Service (Credit) Cost	(0.8)	0
Amortization of Prior Service Credit (Cost)	6.9	6.9
Change for the Year	(12.2)	19.8
Other Postretirement Benefit Plans [Member] | Ohio Power Co [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	$ (11.4)	$ 0.8
Other Postretirement Benefit Plans [Member] | Public Service Co Of Oklahoma [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate	3.30%	4.30%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate	4.30%	3.60%	4.10%
Expected Return on Plan Assets	6.25%	6.00%	6.75%
Health Care Trend Rates
Initial	6.00%	6.25%
Ultimate	4.50%	5.00%
Year Ultimate Reached	2026	2024
Change in Benefit Obligation
Benefit Obligation as of January 1	$ 62.3	$ 69.4
Service Cost	0.6	0.7	$ 0.7
Interest Cost	2.6	2.5	3.2
Actuarial (Gain) Loss	3.8	(5.6)
Plan Amendments	(0.7)	0
Benefit Payments	(5.9)	(6.7)
Participant Contributions	2	2
Benefit Obligation as of December 31	64.7	62.3	69.4
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	84.3	95.5
Actual Gain (Loss) on Plan Assets	17.6	(9.2)
Company Contributions	0	2.7
Participant Contributions	2	2
Benefit Payments	(5.9)	(6.7)
Fair Value of Plan Assets as of December 31	98	84.3	$ 95.5
Funded (Underfunded) Status as of December 31	33.3	22
Benefit Amounts Recognized on the Balance Sheets
Employee Benefits and Pension Assets - Prepaid Benefit Costs	33.3	22
Other Current Liabilities - Accrued Short-term Benefit Liability	0	0
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability	0	0
Funded (Underfunded) Status	33.3	22
Components
Net Actuarial Loss	18.2	28.3
Prior Service Cost (Credit)	(17.8)	(21.6)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year	(8.9)	9
Amortization of Actuarial Gain (Loss)	(1.2)	(0.5)
Prior Service (Credit) Cost	(0.5)	0
Amortization of Prior Service Credit (Cost)	4.3	4.3
Change for the Year	(6.3)	12.8
Benefit Plans (Textuals) [Abstract]
Company Contributions	0	2.7
Other Postretirement Benefit Plans [Member] | Public Service Co Of Oklahoma [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	$ 0.4	$ 6.7
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate	3.30%	4.30%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate	4.30%	3.60%	4.10%
Expected Return on Plan Assets	6.25%	6.00%	6.75%
Health Care Trend Rates
Initial	6.00%	6.25%
Ultimate	4.50%	5.00%
Year Ultimate Reached	2026	2024
Change in Benefit Obligation
Benefit Obligation as of January 1	$ 72.7	$ 80.3
Service Cost	0.8	0.9	$ 0.9
Interest Cost	3.1	2.8	3.6
Actuarial (Gain) Loss	6	(5.9)
Plan Amendments	(0.8)	0
Benefit Payments	(6.6)	(7.7)
Participant Contributions	2.2	2.3
Benefit Obligation as of December 31	77.4	72.7	80.3
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1	98.5	110.4
Actual Gain (Loss) on Plan Assets	23.1	(9.2)
Company Contributions	0	2.7
Participant Contributions	2.2	2.3
Benefit Payments	(6.6)	(7.7)
Fair Value of Plan Assets as of December 31	117.2	98.5	$ 110.4
Funded (Underfunded) Status as of December 31	39.8	25.8
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs	39.8	25.8
Other Current Liabilities - Accrued Short-term Benefit Liability	0	0
Employee Benefits and Pension Obligations - Accrued Long-term Benefit Liability	0	0
Funded (Underfunded) Status	39.8	25.8
Components
Net Actuarial Loss	21.1	33.9
Prior Service Cost (Credit)	(21.6)	(26.2)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year	(11.4)	9.8
Amortization of Actuarial Gain (Loss)	(1.4)	(0.6)
Prior Service (Credit) Cost	(0.6)	0
Amortization of Prior Service Credit (Cost)	5.2	5.2
Change for the Year	(8.2)	14.4
Benefit Plans (Textuals) [Abstract]
Company Contributions	0	2.7
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	0	4.9
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	0	0.7
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	$ (0.5)	$ 2.1

Benefit Plans 2 (Details)

Benefit Plans 2 (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 5,015.4	$ 4,695.9	$ 5,174.1
Year End Allocation
Total	100.00%	100.00%
Pension Plan [Member] | AEP Texas Inc. [Member]
Allocated Assets of Investments	8.70%	8.70%
Pension and Other Postretirement Plans' Assets
Asset Class	$ 435.1	$ 410.7	455.9
Pension Plan [Member] | Appalachian Power Co [Member]
Allocated Assets of Investments	12.70%	12.60%
Pension and Other Postretirement Plans' Assets
Asset Class	$ 637	$ 593.3	651.7
Pension Plan [Member] | Indiana Michigan Power Co [Member]
Allocated Assets of Investments	12.60%	12.40%
Pension and Other Postretirement Plans' Assets
Asset Class	$ 630.5	$ 583.8	636.7
Pension Plan [Member] | Ohio Power Co [Member]
Allocated Assets of Investments	10.00%	9.90%
Pension and Other Postretirement Plans' Assets
Asset Class	$ 499.1	$ 466.1	509.1
Pension Plan [Member] | Public Service Co Of Oklahoma [Member]
Allocated Assets of Investments	5.50%	5.60%
Pension and Other Postretirement Plans' Assets
Asset Class	$ 276.2	$ 261.2	287.8
Pension Plan [Member] | Southwestern Electric Power Co [Member]
Allocated Assets of Investments	5.90%	6.00%
Pension and Other Postretirement Plans' Assets
Asset Class	$ 296.9	$ 281	311.7
Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 1,781.8	$ 1,534.2	1,732.5
Year End Allocation
Total	100.00%	100.00%
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member]
Allocated Assets of Investments	8.30%	8.50%
Pension and Other Postretirement Plans' Assets
Asset Class	$ 148.1	$ 129.9	147.3
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member]
Allocated Assets of Investments	15.20%	15.50%
Pension and Other Postretirement Plans' Assets
Asset Class	$ 271	$ 238.4	273.4
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member]
Allocated Assets of Investments	12.10%	12.20%
Pension and Other Postretirement Plans' Assets
Asset Class	$ 216.3	$ 187.3	211.1
Other Postretirement Benefit Plans [Member] | Ohio Power Co [Member]
Allocated Assets of Investments	11.10%	11.40%
Pension and Other Postretirement Plans' Assets
Asset Class	$ 197.1	$ 175.4	198.5
Other Postretirement Benefit Plans [Member] | Public Service Co Of Oklahoma [Member]
Allocated Assets of Investments	5.50%	5.50%
Pension and Other Postretirement Plans' Assets
Asset Class	$ 98	$ 84.3	95.5
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member]
Allocated Assets of Investments	6.60%	6.40%
Pension and Other Postretirement Plans' Assets
Asset Class	$ 117.2	$ 98.5	$ 110.4
Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	1,337.3	1,127.5
Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	449.3	393.4
Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	991.1	661.2
Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	649.1	515.6
Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	2,687	2,907.2
Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	683.4	625.2
Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Equity Securities [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 1,544.2	$ 1,049.8
Year End Allocation
Total	30.80%	22.40%
Equity Securities [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 824.5	$ 649.7
Year End Allocation
Total	46.30%	42.30%
Equity Securities [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 547.3	$ 370.1
Equity Securities [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	260.8	226.2
Equity Securities [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	996.9	661.4
Equity Securities [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	563.7	419.2
Equity Securities [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	18.3
Equity Securities [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	4.3
Equity Securities [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Equity Securities [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Domestic [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 387.8	$ 277.3
Year End Allocation
Total	7.80%	5.90%
Domestic [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 312.2	$ 233.3
Year End Allocation
Total	17.50%	15.20%
Domestic [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 0	$ 0
Domestic [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Domestic [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	387.8	277.3
Domestic [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	312.2	233.3
Domestic [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Domestic [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Domestic [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Domestic [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
International [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 609.1	$ 384.1
Year End Allocation
Total	12.10%	8.20%
International [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 251.5	$ 185.9
Year End Allocation
Total	14.10%	12.10%
International [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 0	$ 0
International [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
International [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	609.1	384.1
International [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	251.5	185.9
International [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
International [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
International [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
International [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Options [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		$ 18.3
Year End Allocation
Total		0.40%
Options [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		$ 4.3
Year End Allocation
Total		0.30%
Options [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		$ 0
Options [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		0
Options [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		0
Options [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		0
Options [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		18.3
Options [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		4.3
Options [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		0
Options [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		0
Common Collective Trusts [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 547.3	$ 370.1
Year End Allocation
Total	10.90%	7.90%
Common Collective Trusts [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 260.8	$ 226.2
Year End Allocation
Total	14.70%	14.70%
Common Collective Trusts [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 547.3	$ 370.1
Common Collective Trusts [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	260.8	226.2
Common Collective Trusts [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Common Collective Trusts [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Common Collective Trusts [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Common Collective Trusts [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Common Collective Trusts [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Common Collective Trusts [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Fixed Income [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 2,656.8	$ 2,852.8
Year End Allocation
Total	53.00%	60.70%
Fixed Income [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 707.9	$ 622.7
Year End Allocation
Total	39.70%	40.60%
Fixed Income [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 0	$ 0
Fixed Income [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	177.6	163.6
Fixed Income [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	(5.8)	0.2
Fixed Income [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	58.7	42
Fixed Income [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	2,662.6	2,852.6
Fixed Income [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	471.6	417.1
Fixed Income [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Fixed Income [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Common Collective Trust - Debt [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 177.6	$ 163.6
Year End Allocation
Total	10.00%	10.70%
Common Collective Trust - Debt [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 177.6	$ 163.6
Common Collective Trust - Debt [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Common Collective Trust - Debt [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Common Collective Trust - Debt [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
United States Government and Agency Securities [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 1,242.8	$ 1,512.7
Year End Allocation
Total	24.80%	32.20%
United States Government and Agency Securities [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 214.3	$ 181.7
Year End Allocation
Total	12.00%	11.80%
United States Government and Agency Securities [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 0	$ 0
United States Government and Agency Securities [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
United States Government and Agency Securities [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	(5.8)	0.2
United States Government and Agency Securities [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	(0.1)	0.2
United States Government and Agency Securities [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	1,248.6	1,512.5
United States Government and Agency Securities [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	214.4	181.5
United States Government and Agency Securities [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
United States Government and Agency Securities [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Corporate Debt [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 1,143.7	$ 1,082.9
Year End Allocation
Total	22.80%	23.00%
Corporate Debt [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 206.7	$ 188.6
Year End Allocation
Total	11.60%	12.30%
Corporate Debt [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 0	$ 0
Corporate Debt [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Corporate Debt [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Corporate Debt [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Corporate Debt [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	1,143.7	1,082.9
Corporate Debt [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	206.7	188.6
Corporate Debt [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Corporate Debt [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Foreign Debt [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 211.6	$ 221.6
Year End Allocation
Total	4.20%	4.70%
Foreign Debt [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 35.5	$ 35
Year End Allocation
Total	2.00%	2.30%
Foreign Debt [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 0	$ 0
Foreign Debt [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Foreign Debt [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Foreign Debt [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Foreign Debt [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	211.6	221.6
Foreign Debt [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	35.5	35
Foreign Debt [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Foreign Debt [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
State and Local Government [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 55.1	$ 28.2
Year End Allocation
Total	1.10%	0.60%
State and Local Government [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 73.6	$ 53.6
Year End Allocation
Total	4.10%	3.50%
State and Local Government [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 0	$ 0
State and Local Government [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
State and Local Government [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
State and Local Government [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	58.8	41.8
State and Local Government [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	55.1	28.2
State and Local Government [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	14.8	11.8
State and Local Government [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
State and Local Government [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Other - Asset Backed [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 3.6	$ 7.4
Year End Allocation
Total	0.10%	0.20%
Other - Asset Backed [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 0.2	$ 0.2
Year End Allocation
Total	0.00%	0.00%
Other - Asset Backed [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 0	$ 0
Other - Asset Backed [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Other - Asset Backed [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Other - Asset Backed [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Other - Asset Backed [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	3.6	7.4
Other - Asset Backed [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0.2	0.2
Other - Asset Backed [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Other - Asset Backed [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Infrastructure [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 85.8	$ 72.2
Year End Allocation
Total	1.70%	1.50%
Infrastructure [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 85.8	$ 72.2
Infrastructure [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Infrastructure [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Infrastructure [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Real Estate [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 239.4	$ 220.4
Year End Allocation
Total	4.80%	4.70%
Real Estate [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 239.4	$ 220.4
Real Estate [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Real Estate [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Real Estate [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Alternative Investments [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 448.3	$ 444.6
Year End Allocation
Total	8.90%	9.50%
Alternative Investments [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 448.3	$ 444.6
Alternative Investments [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Alternative Investments [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Alternative Investments [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Trusted Owned Life Insurance [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 211.8	$ 203.8
Year End Allocation
Total	11.90%	13.30%
Trusted Owned Life Insurance [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 0	$ 0
Trusted Owned Life Insurance [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Trusted Owned Life Insurance [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	211.8	203.8
Trusted Owned Life Insurance [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
International Equities [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 60.2	$ 49.4
Year End Allocation
Total	3.40%	3.20%
International Equities [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 0	$ 0
International Equities [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
International Equities [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	60.2	49.4
International Equities [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
United States Bonds [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 151.6	$ 154.4
Year End Allocation
Total	8.50%	10.10%
United States Bonds [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 0	$ 0
United States Bonds [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
United States Bonds [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	151.6	154.4
United States Bonds [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Cash and Cash Equivalents [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 61.6	$ 47.8
Year End Allocation
Total	1.20%	1.00%
Cash and Cash Equivalents [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 33.4	$ 59.2
Year End Allocation
Total	1.90%	3.90%
Cash and Cash Equivalents [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 37.2	$ 11.9
Cash and Cash Equivalents [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	6.7	4.8
Cash and Cash Equivalents [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	(0.4)
Cash and Cash Equivalents [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	26.7	54.4
Cash and Cash Equivalents [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	24.4	36.3
Cash and Cash Equivalents [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Cash and Cash Equivalents [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Cash and Cash Equivalents [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Other - Pending Transactions and Accrued Income [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ (20.7)	$ 8.3
Year End Allocation
Total	(0.40%)	0.20%
Other - Pending Transactions and Accrued Income [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 4.2	$ (1.2)
Year End Allocation
Total	0.20%	(0.10%)
Other - Pending Transactions and Accrued Income [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ (20.7)	$ 8.3
Other - Pending Transactions and Accrued Income [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	4.2	(1.2)
Other - Pending Transactions and Accrued Income [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Other - Pending Transactions and Accrued Income [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Other - Pending Transactions and Accrued Income [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Other - Pending Transactions and Accrued Income [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Other - Pending Transactions and Accrued Income [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	0	0
Other - Pending Transactions and Accrued Income [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	$ 0	$ 0

Benefit Plans 3 (Details)

Benefit Plans 3 (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
American Electric Power System Retirement Savings Plans
Cost of Company Matching Contributions	$ 76.4	$ 71.8	$ 74.6
Benefit Plans Textuals [Abstract]
Matching Contributions Provided Percentage	100.00%
Eligible Compensation Contribution by Employee Percentage	1.00%
Second Matching Contributions Provided Percentage	70.00%
Second Eligible Compensation Contribution by Employee Percentage	5.00%
Multiemployer Plans Withdrawal Obligation	$ 20	15
Noncurrent Regulatory Assets	3,158.8	3,310.4
Noncurrent Regulatory Liabilities	8,457.6	8,540.3
UMWA Withdrawal Obligation [Member]
Benefit Plans Textuals [Abstract]
Noncurrent Regulatory Assets	2
Noncurrent Regulatory Liabilities		3
AEP Texas Inc. [Member]
American Electric Power System Retirement Savings Plans
Cost of Company Matching Contributions	$ 5.9	5.7	6
Benefit Plans Textuals [Abstract]
Matching Contributions Provided Percentage	100.00%
Eligible Compensation Contribution by Employee Percentage	1.00%
Second Matching Contributions Provided Percentage	70.00%
Second Eligible Compensation Contribution by Employee Percentage	5.00%
Noncurrent Regulatory Assets	$ 280.6	430
Noncurrent Regulatory Liabilities	1,316.9	1,344.3
Appalachian Power Co [Member]
American Electric Power System Retirement Savings Plans
Cost of Company Matching Contributions	$ 7.5	7.5	7.4
Benefit Plans Textuals [Abstract]
Matching Contributions Provided Percentage	100.00%
Eligible Compensation Contribution by Employee Percentage	1.00%
Second Matching Contributions Provided Percentage	70.00%
Second Eligible Compensation Contribution by Employee Percentage	5.00%
Noncurrent Regulatory Assets	$ 457.2	475.8
Noncurrent Regulatory Liabilities	1,268.7	1,449.7
Indiana Michigan Power Co [Member]
American Electric Power System Retirement Savings Plans
Cost of Company Matching Contributions	$ 11	10.5	10.7
Benefit Plans Textuals [Abstract]
Matching Contributions Provided Percentage	100.00%
Eligible Compensation Contribution by Employee Percentage	1.00%
Second Matching Contributions Provided Percentage	70.00%
Second Eligible Compensation Contribution by Employee Percentage	5.00%
Noncurrent Regulatory Assets	$ 482.1	512.5
Noncurrent Regulatory Liabilities	1,891.4	1,574.5
Ohio Power Co [Member]
American Electric Power System Retirement Savings Plans
Cost of Company Matching Contributions	$ 6.6	6.3	6.1
Benefit Plans Textuals [Abstract]
Matching Contributions Provided Percentage	100.00%
Eligible Compensation Contribution by Employee Percentage	1.00%
Second Matching Contributions Provided Percentage	70.00%
Second Eligible Compensation Contribution by Employee Percentage	5.00%
Noncurrent Regulatory Assets	$ 351.8	387.5
Noncurrent Regulatory Liabilities	1,090.9	1,221.2
Public Service Co Of Oklahoma [Member]
American Electric Power System Retirement Savings Plans
Cost of Company Matching Contributions	$ 4.6	4.5	5
Benefit Plans Textuals [Abstract]
Matching Contributions Provided Percentage	100.00%
Eligible Compensation Contribution by Employee Percentage	1.00%
Second Matching Contributions Provided Percentage	70.00%
Second Eligible Compensation Contribution by Employee Percentage	5.00%
Noncurrent Regulatory Assets	$ 375.2	369
Noncurrent Regulatory Liabilities	837.2	864.7
Southwestern Electric Power Co [Member]
American Electric Power System Retirement Savings Plans
Cost of Company Matching Contributions	$ 6.2	5.9	6
Benefit Plans Textuals [Abstract]
Matching Contributions Provided Percentage	100.00%
Eligible Compensation Contribution by Employee Percentage	1.00%
Second Matching Contributions Provided Percentage	70.00%
Second Eligible Compensation Contribution by Employee Percentage	5.00%
Noncurrent Regulatory Assets	$ 222.4	230.8
Noncurrent Regulatory Liabilities	892.3	923
Pension Plans [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	4,998.7	4,625.6
Underfunded Benefit Obligation
Projected Benefit Obligation	5,236.8	4,810.3	5,215.8
Accumulated Benefit Obligation	4,998.7	4,625.6
Fair Value of Plan Assets	5,015.4	4,695.9	5,174.1
Underfunded Status, Projected Benefit Obligation	(221.4)	(114.4)
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2020	6.1
Components of Net Periodic Benefit Cost
Service Cost	95.5	97.6	96.5
Interest Cost	204.4	187.8	203.1
Expected Return on Plan Assets	(296)	(290.3)	(284.8)
Amortization of Prior Service Cost (Credit)	0	0	1
Amortization of Net Actuarial Loss	57.6	85.2	82.8
Settlements	0	2.6	0
Net Periodic Benefit Cost (Credit)	61.5	82.9	98.6
Capitalized Portion	(38.6)	(41.1)	(39.9)
Net Periodic Benefit Cost (Credit) Recognized in Expense	22.9	41.8	58.7
Pension Plans [Member] | Pension Payments [Member]
Estimated Future Benefit Payments and Contributions
2020	378.1
2021	382.8
2022	380.5
2023	383.8
2024	382.9
Years 2025 to 2029, in Total	1,800.7
Pension Plans [Member] | AEP Texas Inc. [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	421.1	396.8
Underfunded Benefit Obligation
Projected Benefit Obligation	441.2	409.3	441.3
Accumulated Benefit Obligation	421.1	396.8
Fair Value of Plan Assets	435.1	410.7	455.9
Underfunded Status, Projected Benefit Obligation	(6.1)
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2020	0.4
Components of Net Periodic Benefit Cost
Service Cost	8.6	9.2	8.6
Interest Cost	17.5	16	17.1
Expected Return on Plan Assets	(25.8)	(25.6)	(25)
Amortization of Prior Service Cost (Credit)	0	0	0
Amortization of Net Actuarial Loss	4.9	7.2	7
Net Periodic Benefit Cost (Credit)	5.2	6.8	7.7
Capitalized Portion	(4.5)	(4.8)	(4)
Net Periodic Benefit Cost (Credit) Recognized in Expense	0.7	2	3.7
Pension Plans [Member] | AEP Texas Inc. [Member] | Pension Payments [Member]
Estimated Future Benefit Payments and Contributions
2020	37.5
2021	37.3
2022	35.9
2023	36.6
2024	36.3
Years 2025 to 2029, in Total	162.2
Pension Plans [Member] | Appalachian Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	627.5	588.5
Underfunded Benefit Obligation
Projected Benefit Obligation	647.2	603.1	665
Accumulated Benefit Obligation	627.5	588.5
Fair Value of Plan Assets	637	593.3	651.7
Underfunded Status, Projected Benefit Obligation	(10.2)	(9.8)
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2020	0
Components of Net Periodic Benefit Cost
Service Cost	9.4	9.3	9.4
Interest Cost	25.2	23.5	25.7
Expected Return on Plan Assets	(37.4)	(36.6)	(35.8)
Amortization of Prior Service Cost (Credit)	0	0	0.2
Amortization of Net Actuarial Loss	7	10.6	10.4
Net Periodic Benefit Cost (Credit)	4.2	6.8	9.9
Capitalized Portion	(4)	(3.8)	(4)
Net Periodic Benefit Cost (Credit) Recognized in Expense	0.2	3	5.9
Pension Plans [Member] | Appalachian Power Co [Member] | Pension Payments [Member]
Estimated Future Benefit Payments and Contributions
2020	45.8
2021	46
2022	45.7
2023	46.1
2024	46.8
Years 2025 to 2029, in Total	217.4
Pension Plans [Member] | Indiana Michigan Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	586.9	536.9
Underfunded Benefit Obligation
Projected Benefit Obligation	616.1	567	624.3
Accumulated Benefit Obligation	586.9	536.9
Fair Value of Plan Assets	630.5	583.8	636.7
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2020	0
Components of Net Periodic Benefit Cost
Service Cost	13.4	13.6	14
Interest Cost	23.8	22.1	24.3
Expected Return on Plan Assets	(36.8)	(35.7)	(34.6)
Amortization of Prior Service Cost (Credit)	0	0	0.2
Amortization of Net Actuarial Loss	6.6	9.8	9.7
Net Periodic Benefit Cost (Credit)	7	9.8	13.6
Capitalized Portion	(3.4)	(5.6)	(5.5)
Net Periodic Benefit Cost (Credit) Recognized in Expense	3.6	4.2	8.1
Pension Plans [Member] | Indiana Michigan Power Co [Member] | Pension Payments [Member]
Estimated Future Benefit Payments and Contributions
2020	40.1
2021	40.5
2022	42.5
2023	42.2
2024	42.8
Years 2025 to 2029, in Total	211.6
Pension Plans [Member] | Ohio Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	464.3	438.5
Underfunded Benefit Obligation
Projected Benefit Obligation	487.8	453.9	501.1
Accumulated Benefit Obligation	464.3	438.5
Fair Value of Plan Assets	499.1	466.1	509.1
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2020	0
Components of Net Periodic Benefit Cost
Service Cost	7.9	7.7	7.5
Interest Cost	19.1	17.7	19.4
Expected Return on Plan Assets	(29.3)	(28.8)	(27.9)
Amortization of Prior Service Cost (Credit)	0	0	0.1
Amortization of Net Actuarial Loss	5.3	8	7.8
Net Periodic Benefit Cost (Credit)	3	4.6	6.9
Capitalized Portion	(3.7)	(3.6)	(3.3)
Net Periodic Benefit Cost (Credit) Recognized in Expense	(0.7)	1	3.6
Pension Plans [Member] | Ohio Power Co [Member] | Pension Payments [Member]
Estimated Future Benefit Payments and Contributions
2020	36.2
2021	36.1
2022	35.7
2023	35.8
2024	34
Years 2025 to 2029, in Total	161.1
Pension Plans [Member] | Public Service Co Of Oklahoma [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	250.5	240.2
Underfunded Benefit Obligation
Projected Benefit Obligation	267.5	253.8	276.6
Accumulated Benefit Obligation	250.5	240.2
Fair Value of Plan Assets	276.2	261.2	287.8
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2020	0.1
Components of Net Periodic Benefit Cost
Service Cost	6.5	7	6.4
Interest Cost	10.6	9.9	10.7
Expected Return on Plan Assets	(16.3)	(16.1)	(15.6)
Amortization of Prior Service Cost (Credit)	0	0	0
Amortization of Net Actuarial Loss	2.9	4.4	4.3
Net Periodic Benefit Cost (Credit)	3.7	5.2	5.8
Capitalized Portion	(2.4)	(2.6)	(2.1)
Net Periodic Benefit Cost (Credit) Recognized in Expense	1.3	2.6	3.7
Pension Plans [Member] | Public Service Co Of Oklahoma [Member] | Pension Payments [Member]
Estimated Future Benefit Payments and Contributions
2020	20.9
2021	21.3
2022	21.2
2023	22.6
2024	21.5
Years 2025 to 2029, in Total	98.3
Pension Plans [Member] | Southwestern Electric Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	293.2	272.8
Underfunded Benefit Obligation
Projected Benefit Obligation	314.2	291.4	314.6
Accumulated Benefit Obligation	293.2	272.8
Fair Value of Plan Assets	296.9	281	311.7
Underfunded Status, Projected Benefit Obligation	(17.3)	(10.4)
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2020	0.1
Components of Net Periodic Benefit Cost
Service Cost	8.6	9.3	8.7
Interest Cost	12.4	11.3	12.3
Expected Return on Plan Assets	(17.7)	(17.3)	(17)
Amortization of Prior Service Cost (Credit)	0	0	0.1
Amortization of Net Actuarial Loss	3.4	5.1	4.9
Settlements	0	0.4	0
Net Periodic Benefit Cost (Credit)	6.7	8.8	9
Capitalized Portion	(2.9)	(3.1)	(2.7)
Net Periodic Benefit Cost (Credit) Recognized in Expense	3.8	5.7	6.3
Pension Plans [Member] | Southwestern Electric Power Co [Member] | Pension Payments [Member]
Estimated Future Benefit Payments and Contributions
2020	24
2021	24.7
2022	25.2
2023	25.4
2024	25.8
Years 2025 to 2029, in Total	119.6
Qualified Pension Plans [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	4,929	4,560.7
Underfunded Benefit Obligation
Accumulated Benefit Obligation	4,929	4,560.7
Qualified Pension Plans [Member] | AEP Texas Inc. [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	417.5	393.2
Underfunded Benefit Obligation
Accumulated Benefit Obligation	417.5	393.2
Qualified Pension Plans [Member] | Appalachian Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	627.3	588.3
Underfunded Benefit Obligation
Accumulated Benefit Obligation	627.3	588.3
Qualified Pension Plans [Member] | Indiana Michigan Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	586.3	536.3
Underfunded Benefit Obligation
Accumulated Benefit Obligation	586.3	536.3
Qualified Pension Plans [Member] | Ohio Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	464.2	438.3
Underfunded Benefit Obligation
Accumulated Benefit Obligation	464.2	438.3
Qualified Pension Plans [Member] | Public Service Co Of Oklahoma [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	248.9	238
Underfunded Benefit Obligation
Accumulated Benefit Obligation	248.9	238
Qualified Pension Plans [Member] | Southwestern Electric Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	291.9	271.6
Underfunded Benefit Obligation
Accumulated Benefit Obligation	291.9	271.6
Nonqualified Pension Plans [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	69.7	64.9
Underfunded Benefit Obligation
Accumulated Benefit Obligation	69.7	64.9
Fair Value of Plan Assets	0	0
Underfunded Status, Accumulated Benefit Obligation	(69.7)	(64.9)
Nonqualified Pension Plans [Member] | AEP Texas Inc. [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	3.6	3.6
Underfunded Benefit Obligation
Projected Benefit Obligation		3.8
Accumulated Benefit Obligation	3.6	3.6
Fair Value of Plan Assets	0	0
Underfunded Status, Projected Benefit Obligation		(3.8)
Underfunded Status, Accumulated Benefit Obligation	(3.6)	(3.6)
Nonqualified Pension Plans [Member] | Appalachian Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	0.2	0.2
Underfunded Benefit Obligation
Accumulated Benefit Obligation	0.2	0.2
Fair Value of Plan Assets	0	0
Underfunded Status, Accumulated Benefit Obligation	(0.2)	(0.2)
Nonqualified Pension Plans [Member] | Indiana Michigan Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	0.6	0.6
Underfunded Benefit Obligation
Projected Benefit Obligation	1.5	1.2
Accumulated Benefit Obligation	0.6	0.6
Fair Value of Plan Assets	0	0
Underfunded Status, Projected Benefit Obligation	(1.5)	(1.2)
Underfunded Status, Accumulated Benefit Obligation	(0.6)	(0.6)
Nonqualified Pension Plans [Member] | Ohio Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	0.1	0.2
Underfunded Benefit Obligation
Projected Benefit Obligation	0.4	0.4
Accumulated Benefit Obligation	0.1	0.2
Fair Value of Plan Assets	0	0
Underfunded Status, Projected Benefit Obligation	(0.4)	(0.4)
Underfunded Status, Accumulated Benefit Obligation	(0.1)	(0.2)
Nonqualified Pension Plans [Member] | Public Service Co Of Oklahoma [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	1.6	2.2
Underfunded Benefit Obligation
Projected Benefit Obligation	1.9	2.3
Accumulated Benefit Obligation	1.6	2.2
Fair Value of Plan Assets	0	0
Underfunded Status, Projected Benefit Obligation	(1.9)	(2.3)
Underfunded Status, Accumulated Benefit Obligation	(1.6)	(2.2)
Nonqualified Pension Plans [Member] | Southwestern Electric Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	1.3	1.2
Underfunded Benefit Obligation
Accumulated Benefit Obligation	1.3	1.2
Fair Value of Plan Assets	0	0
Underfunded Status, Accumulated Benefit Obligation	(1.3)	(1.2)
Other Postretirement Benefit Plans [Member]
Underfunded Benefit Obligation
Projected Benefit Obligation	1,225.4	1,194.5	1,332
Fair Value of Plan Assets	1,781.8	1,534.2	1,732.5
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2020	3.4
Components of Net Periodic Benefit Cost
Service Cost	9.5	11.6	11.2
Interest Cost	50.5	47.4	59.3
Expected Return on Plan Assets	(93.7)	(102.2)	(101.3)
Amortization of Prior Service Cost (Credit)	(69.1)	(69.1)	(69.1)
Amortization of Net Actuarial Loss	22.1	10.5	36.7
Settlements	0	0	0
Net Periodic Benefit Cost (Credit)	(80.7)	(101.8)	(63.2)
Capitalized Portion	(3.8)	(4.9)	25.6
Net Periodic Benefit Cost (Credit) Recognized in Expense	(84.5)	(106.7)	(37.6)
Other Postretirement Benefit Plans [Member] | Benefit Payments [Member]
Estimated Future Benefit Payments and Contributions
2020	126.3
2021	124
2022	125.2
2023	125
2024	124.6
Years 2025 to 2029, in Total	592.6
Other Postretirement Benefit Plans [Member] | Medicare Subsidy Receipts [Member]
Estimated Future Benefit Payments and Contributions
2020	0.2
2021	0.3
2022	0.3
2023	0.3
2024	0.3
Years 2025 to 2029, in Total	1.4
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member]
Underfunded Benefit Obligation
Projected Benefit Obligation	97.8	95.9	107.1
Fair Value of Plan Assets	148.1	129.9	147.3
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2020	0.1
Components of Net Periodic Benefit Cost
Service Cost	0.8	0.9	0.9
Interest Cost	4	3.8	4.9
Expected Return on Plan Assets	(7.8)	(8.6)	(8.8)
Amortization of Prior Service Cost (Credit)	(5.9)	(5.9)	(5.8)
Amortization of Net Actuarial Loss	1.8	0.8	3.2
Net Periodic Benefit Cost (Credit)	(7.1)	(9)	(5.6)
Capitalized Portion	(0.4)	(0.5)	2.9
Net Periodic Benefit Cost (Credit) Recognized in Expense	(7.5)	(9.5)	(2.7)
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member] | Benefit Payments [Member]
Estimated Future Benefit Payments and Contributions
2020	10
2021	10
2022	10.4
2023	10.6
2024	10.7
Years 2025 to 2029, in Total	50.8
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member] | Medicare Subsidy Receipts [Member]
Estimated Future Benefit Payments and Contributions
2020	0
2021	0
2022	0
2023	0
2024	0
Years 2025 to 2029, in Total	0
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member]
Underfunded Benefit Obligation
Projected Benefit Obligation	203.5	205.5	236.5
Fair Value of Plan Assets	271	238.4	273.4
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2020	2
Components of Net Periodic Benefit Cost
Service Cost	1	1.1	1.1
Interest Cost	8.7	8.2	10.6
Expected Return on Plan Assets	(14.6)	(16)	(16.5)
Amortization of Prior Service Cost (Credit)	(10.1)	(10)	(10.1)
Amortization of Net Actuarial Loss	3.7	1.9	6.3
Net Periodic Benefit Cost (Credit)	(11.3)	(14.8)	(8.6)
Capitalized Portion	(0.4)	(0.5)	3.5
Net Periodic Benefit Cost (Credit) Recognized in Expense	(11.7)	(15.3)	(5.1)
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member] | Benefit Payments [Member]
Estimated Future Benefit Payments and Contributions
2020	22.5
2021	21.8
2022	21.6
2023	21.2
2024	21.1
Years 2025 to 2029, in Total	97.8
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member] | Medicare Subsidy Receipts [Member]
Estimated Future Benefit Payments and Contributions
2020	0.1
2021	0.2
2022	0.2
2023	0.1
2024	0.1
Years 2025 to 2029, in Total	0.6
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member]
Underfunded Benefit Obligation
Projected Benefit Obligation	142.9	138.3	153.5
Fair Value of Plan Assets	216.3	187.3	211.1
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2020	0
Components of Net Periodic Benefit Cost
Service Cost	1.4	1.6	1.6
Interest Cost	5.8	5.4	6.9
Expected Return on Plan Assets	(11.4)	(12.3)	(12.2)
Amortization of Prior Service Cost (Credit)	(9.4)	(9.5)	(9.4)
Amortization of Net Actuarial Loss	2.7	1.2	4.4
Net Periodic Benefit Cost (Credit)	(10.9)	(13.6)	(8.7)
Capitalized Portion	(0.4)	(0.7)	3.5
Net Periodic Benefit Cost (Credit) Recognized in Expense	(11.3)	(14.3)	(5.2)
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member] | Benefit Payments [Member]
Estimated Future Benefit Payments and Contributions
2020	15.2
2021	15.2
2022	15.5
2023	15.5
2024	15.4
Years 2025 to 2029, in Total	72.8
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member] | Medicare Subsidy Receipts [Member]
Estimated Future Benefit Payments and Contributions
2020	0
2021	0
2022	0
2023	0
2024	0
Years 2025 to 2029, in Total	0
Other Postretirement Benefit Plans [Member] | Ohio Power Co [Member]
Underfunded Benefit Obligation
Projected Benefit Obligation	130.2	129.5	144.3
Fair Value of Plan Assets	197.1	175.4	198.5
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2020	0
Components of Net Periodic Benefit Cost
Service Cost	0.8	0.9	0.9
Interest Cost	5.5	5.1	6.7
Expected Return on Plan Assets	(10.8)	(11.7)	(11.9)
Amortization of Prior Service Cost (Credit)	(6.9)	(6.9)	(6.9)
Amortization of Net Actuarial Loss	2.5	1.1	4.3
Net Periodic Benefit Cost (Credit)	(8.9)	(11.5)	(6.9)
Capitalized Portion	(0.4)	(0.4)	3.3
Net Periodic Benefit Cost (Credit) Recognized in Expense	(9.3)	(11.9)	(3.6)
Other Postretirement Benefit Plans [Member] | Ohio Power Co [Member] | Benefit Payments [Member]
Estimated Future Benefit Payments and Contributions
2020	14.8
2021	14.2
2022	14.4
2023	14.3
2024	14.1
Years 2025 to 2029, in Total	65.4
Other Postretirement Benefit Plans [Member] | Ohio Power Co [Member] | Medicare Subsidy Receipts [Member]
Estimated Future Benefit Payments and Contributions
2020	0
2021	0
2022	0
2023	0
2024	0
Years 2025 to 2029, in Total	0
Other Postretirement Benefit Plans [Member] | Public Service Co Of Oklahoma [Member]
Underfunded Benefit Obligation
Projected Benefit Obligation	64.7	62.3	69.4
Fair Value of Plan Assets	98	84.3	95.5
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2020	0
Components of Net Periodic Benefit Cost
Service Cost	0.6	0.7	0.7
Interest Cost	2.6	2.5	3.2
Expected Return on Plan Assets	(5.1)	(5.6)	(5.6)
Amortization of Prior Service Cost (Credit)	(4.3)	(4.3)	(4.3)
Amortization of Net Actuarial Loss	1.2	0.5	2
Net Periodic Benefit Cost (Credit)	(5)	(6.2)	(4)
Capitalized Portion	(0.2)	(0.3)	1.4
Net Periodic Benefit Cost (Credit) Recognized in Expense	(5.2)	(6.5)	(2.6)
Other Postretirement Benefit Plans [Member] | Public Service Co Of Oklahoma [Member] | Benefit Payments [Member]
Estimated Future Benefit Payments and Contributions
2020	6.8
2021	6.7
2022	6.9
2023	7
2024	7.1
Years 2025 to 2029, in Total	33.7
Other Postretirement Benefit Plans [Member] | Public Service Co Of Oklahoma [Member] | Medicare Subsidy Receipts [Member]
Estimated Future Benefit Payments and Contributions
2020	0
2021	0
2022	0
2023	0
2024	0
Years 2025 to 2029, in Total	0
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member]
Underfunded Benefit Obligation
Projected Benefit Obligation	77.4	72.7	80.3
Fair Value of Plan Assets	117.2	98.5	110.4
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2020	0
Components of Net Periodic Benefit Cost
Service Cost	0.8	0.9	0.9
Interest Cost	3.1	2.8	3.6
Expected Return on Plan Assets	(5.9)	(6.4)	(6.3)
Amortization of Prior Service Cost (Credit)	(5.2)	(5.2)	(5.2)
Amortization of Net Actuarial Loss	1.4	0.6	2.3
Settlements	0	0	0
Net Periodic Benefit Cost (Credit)	(5.8)	(7.3)	(4.7)
Capitalized Portion	(0.3)	(0.3)	1.4
Net Periodic Benefit Cost (Credit) Recognized in Expense	(6.1)	$ (7.6)	$ (3.3)
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member] | Benefit Payments [Member]
Estimated Future Benefit Payments and Contributions
2020	7.5
2021	7.7
2022	8
2023	8.2
2024	8.4
Years 2025 to 2029, in Total	40.6
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member] | Medicare Subsidy Receipts [Member]
Estimated Future Benefit Payments and Contributions
2020	0
2021	0
2022	0
2023	0
2024	0
Years 2025 to 2029, in Total	$ 0

Business Segments (Details)

Business Segments (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reportable Segment Information
Revenue from Contracts with Customers									$ 15,561.4	$ 16,195.7	$ 15,424.9
Sales to AEP Affiliates									0	0	0
Total Revenues	$ 3,616	$ 4,315	$ 3,573.6	$ 4,056.8	$ 3,801.1	$ 4,333.1	$ 4,013.2	$ 4,048.3	15,561.4	16,195.7	15,424.9
Asset Impairments and Other Related Charges									156.4	70.6	87.1
Utilities Operating Expense, Depreciation and Amortization									2,514.5	2,286.6	1,997.2
Allowance for Equity Funds Used During Construction									168.4	132.5	93.7
Interest Expense									1,072.5	984.4	895
Income Tax Expense (Benefit)									(12.9)	115.3	969.7
Equity Earnings (Loss) of Unconsolidated Subsidiaries									72.1	73.1	82.4
NET INCOME (LOSS)	152.7	733.9	459.1	574.1	364.8	579.7	530.1	456.7	1,919.8	1,931.3	1,928.9
Gross Property Additions									6,969.8	6,325.5	5,698.1
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)	79,145.7				73,085.2				79,145.7	73,085.2
Accumulated Depreciation and Amortization	19,007.6				17,986.1				19,007.6	17,986.1
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	60,138.1				55,099.1				60,138.1	55,099.1
Total Assets	75,892.3				68,802.8				75,892.3	68,802.8	64,729.1
Investments in Equity Method Investees	1,356.6				846.2				1,356.6	846.2
Affiliated Long Term Debt Current	0								0
Long-term Debt Due Within One Year	1,598.7				1,698.5				1,598.7	1,698.5
Long-term Debt - Affiliated	0				0				0	0
Long-term Debt	25,126.8				21,648.2				25,126.8	21,648.2
Total Long-term Debt Outstanding	26,725.5				23,346.7				26,725.5	23,346.7
AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contracts with Customers									1,042.1	832
Sales to AEP Affiliates									806.7	598.9	568.1
Total Revenues	251.3	259.7	266.9	243.5	189.9	194.4	200.1	191.7	1,021.4	776.1	706.9
Utilities Operating Expense, Depreciation and Amortization									176	133.9	95.7
Interest Income									3	2.5	1.2
Allowance for Equity Funds Used During Construction									84.3	70.6	49
Interest Expense									97.4	83.2	70.2
Income Tax Expense (Benefit)									117.4	84.1	142.2
NET INCOME (LOSS)	91.8	$ 107.6	$ 136	$ 104.3	71.7	$ 78.1	$ 82	$ 84.1	439.7	315.9	270.7
Gross Property Additions									1,419.5	1,570.8	1,522.5
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)	9,893.2				8,268.1				9,893.2	8,268.1
Accumulated Depreciation and Amortization	402.3				271.9				402.3	271.9
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	9,490.9				7,996.2				9,490.9	7,996.2
Notes Receivable, Related Parties	0				0				0	0
Total Assets	9,890.8				8,394.1				9,890.8	8,394.1	7,082.1
Long-term Debt Due Within One Year	0				85				0	85
Long-term Debt	3,427.3				2,738				3,427.3	2,738
Total Long-term Debt Outstanding	3,427.3				2,823				3,427.3	2,823
Vertically Integrated Utilities [Member]
Reportable Segment Information
Revenue from Contracts with Customers									9,245.7	9,556.7	9,095.1
Transmission and Distribution Utilities Revenues [Member]
Reportable Segment Information
Revenue from Contracts with Customers									4,319	4,552.3	4,328.9
Transmission [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contracts with Customers									214.6	177	138
Generation and Marketing Revenues [Member]
Reportable Segment Information
Revenue from Contracts with Customers									1,721.8	1,818.1	1,771.4
Other Revenues [Member]
Reportable Segment Information
Revenue from Contracts with Customers									274.9	268.6	229.5
Total Revenues									61.7	25
Other Revenues [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contracts with Customers									0.1	0.2	0.8
Total Revenues									0	0
Reconciling Adjustments [Member]
Reportable Segment Information
Revenue from Contracts with Customers									0	0	0
Sales to AEP Affiliates									(1,314.8)	(942.4)	(949)
Total Revenues									(1,314.8)	(942.4)	(949)
Asset Impairments and Other Related Charges									0	0	0
Utilities Operating Expense, Depreciation and Amortization									24.5	57.1	60.5
Interest Expense									(66.1)	(59.7)	(44.3)
Income Tax Expense (Benefit)									0	0	0
Equity Earnings (Loss) of Unconsolidated Subsidiaries									0	0	0
NET INCOME (LOSS)									0	0	0
Gross Property Additions									(20.4)	(39.2)	(90.4)
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)	(354.5)				(354.6)				(354.5)	(354.6)
Accumulated Depreciation and Amortization	(186.4)				(186.5)				(186.4)	(186.5)
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	(168.1)				(168.1)				(168.1)	(168.1)
Total Assets	(3,801.3)				(2,714.8)				(3,801.3)	(2,714.8)	(3,022)
Investments in Equity Method Investees	0				0				0	0
Affiliated Long Term Debt Current	(20)								(20)
Long-term Debt Due Within One Year	0				0				0	0
Long-term Debt - Affiliated	(39)				(82.2)				(39)	(82.2)
Long-term Debt	0				0				0	0
Total Long-term Debt Outstanding	(59)				(82.2)				(59)	(82.2)
Reconciling Adjustments [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contracts with Customers									0	0	0
Sales to AEP Affiliates									0	0	0
Total Revenues									0	0	0
Utilities Operating Expense, Depreciation and Amortization									0	0	0
Interest Income									(122.1)	(103.4)	(82.4)
Allowance for Equity Funds Used During Construction									0	0	0
Interest Expense									(122.1)	(103.4)	(82.4)
Income Tax Expense (Benefit)									0	0	0
NET INCOME (LOSS)									0	0	0
Gross Property Additions									0	0	0
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)	0				0				0	0
Accumulated Depreciation and Amortization	0				0				0	0
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	0				0				0	0
Notes Receivable, Related Parties	(3,427.3)				(2,823)				(3,427.3)	(2,823)
Total Assets	(3,493.3)				(2,869.8)				(3,493.3)	(2,869.8)	(2,594.9)
Total Long-term Debt Outstanding	(3,465)				(2,850)				(3,465)	(2,850)
Reconciling Adjustments [Member] | Other Revenues [Member]
Reportable Segment Information
Sales to AEP Affiliates										98
Total Revenues									(139.3)	(98)
Reconciling Adjustments [Member] | Other Revenues [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contracts with Customers									0	0	0
Vertically Integrated Utilities [Member]
Reportable Segment Information
Sales to AEP Affiliates									121.4	88.8	96.9
Total Revenues									9,367.1	9,645.5	9,192
Asset Impairments and Other Related Charges									92.9	3.4	33.6
Utilities Operating Expense, Depreciation and Amortization									1,447	1,316.2	1,142.5
Interest Expense									568.3	567.8	540
Income Tax Expense (Benefit)									(97.7)	5.7	425.6
Equity Earnings (Loss) of Unconsolidated Subsidiaries									3	2.7	(3.8)
NET INCOME (LOSS)									985.6	995.5	803.3
Gross Property Additions									2,437.4	2,282.2	2,343.2
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)	47,323.7				45,365.1				47,323.7	45,365.1
Accumulated Depreciation and Amortization	14,580.4				13,822.5				14,580.4	13,822.5
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	32,743.3				31,542.6				32,743.3	31,542.6
Total Assets	41,228.8				38,874.3				41,228.8	38,874.3	37,579.7
Investments in Equity Method Investees	41.7				39.6				41.7	39.6
Affiliated Long Term Debt Current	20								20
Long-term Debt Due Within One Year	704.7				1,066.3				704.7	1,066.3
Long-term Debt - Affiliated	39				50				39	50
Long-term Debt	12,162				11,442.7				12,162	11,442.7
Total Long-term Debt Outstanding	12,925.7				12,559				12,925.7	12,559
Vertically Integrated Utilities [Member] | Vertically Integrated Utilities [Member]
Reportable Segment Information
Revenue from Contracts with Customers									9,245.7	9,556.7	9,095.1
Vertically Integrated Utilities [Member] | Other Revenues [Member]
Reportable Segment Information
Total Revenues									0	(10.5)
Transmission and Distribution Companies [Member]
Reportable Segment Information
Sales to AEP Affiliates									163.5	100.8	90.4
Total Revenues									4,482.5	4,653.1	4,419.3
Asset Impairments and Other Related Charges									32.5	0	0
Utilities Operating Expense, Depreciation and Amortization									789.5	734.1	667.5
Interest Expense									243.3	248.1	244.1
Income Tax Expense (Benefit)									(25.2)	42.4	127.2
Equity Earnings (Loss) of Unconsolidated Subsidiaries									0	0	0
NET INCOME (LOSS)									451	527.4	636.4
Gross Property Additions									2,074.3	2,162.4	1,558.4
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)	19,773.3				18,126.7				19,773.3	18,126.7
Accumulated Depreciation and Amortization	3,911.2				3,833.7				3,911.2	3,833.7
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	15,862.1				14,293				15,862.1	14,293
Total Assets	18,757.5				17,083.4				18,757.5	17,083.4	16,060.7
Investments in Equity Method Investees	2.5				2.9				2.5	2.9
Affiliated Long Term Debt Current	0								0
Long-term Debt Due Within One Year	392.2				549.1				392.2	549.1
Long-term Debt - Affiliated	0				0				0	0
Long-term Debt	6,248.1				5,048.8				6,248.1	5,048.8
Total Long-term Debt Outstanding	6,640.3				5,597.9				6,640.3	5,597.9
Transmission and Distribution Companies [Member] | Transmission and Distribution Utilities Revenues [Member]
Reportable Segment Information
Revenue from Contracts with Customers									4,319	4,552.3	4,328.9
Transmission and Distribution Companies [Member] | Other Revenues [Member]
Reportable Segment Information
Total Revenues									150	102.3
AEP Transmission Holdco
Reportable Segment Information
Sales to AEP Affiliates									813	555.5	588.3
Total Revenues									1,073.2	804.1	766.7
Asset Impairments and Other Related Charges									0	0	0
Utilities Operating Expense, Depreciation and Amortization									183.4	137.8	102.2
Interest Expense									103.3	90.7	72.8
Income Tax Expense (Benefit)									136.2	95.3	189.8
Equity Earnings (Loss) of Unconsolidated Subsidiaries									72.8	68.7	88.6
NET INCOME (LOSS)									520.1	373	355.6
Gross Property Additions									1,458.9	1,614.1	1,542.8
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)	10,334				8,659.5				10,334	8,659.5
Accumulated Depreciation and Amortization	418.9				282.8				418.9	282.8
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	9,915.1				8,376.7				9,915.1	8,376.7
Total Assets	11,143.5				9,543.7				11,143.5	9,543.7	8,141.8
Investments in Equity Method Investees	787.5				750.9				787.5	750.9
Affiliated Long Term Debt Current	0								0
Long-term Debt Due Within One Year	0				85				0	85
Long-term Debt - Affiliated	0				0				0	0
Long-term Debt	3,593.8				2,888.6				3,593.8	2,888.6
Total Long-term Debt Outstanding	3,593.8				2,973.6				3,593.8	2,973.6
AEP Transmission Holdco | Transmission [Member]
Reportable Segment Information
Revenue from Contracts with Customers									260.2	248.6	178.4
Generation and Marketing [Member]
Reportable Segment Information
Sales to AEP Affiliates									135.8	122.2	103.7
Total Revenues									1,857.6	1,940.3	1,875.1
Asset Impairments and Other Related Charges									31	47.7	53.5
Utilities Operating Expense, Depreciation and Amortization									69.5	41	24.2
Interest Expense									30	14.9	18.5
Income Tax Expense (Benefit)									(53.8)	(49.2)	189.7
Equity Earnings (Loss) of Unconsolidated Subsidiaries									(3.8)	0.5	0
NET INCOME (LOSS)									104.1	134.7	166
Gross Property Additions									1,005.1	289.7	328.5
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)	1,650.8				893.3				1,650.8	893.3
Accumulated Depreciation and Amortization	99				47				99	47
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	1,551.8				846.3				1,551.8	846.3
Total Assets	3,123.8				1,979.7				3,123.8	1,979.7	2,009.8
Investments in Equity Method Investees	459.5				26.7				459.5	26.7
Affiliated Long Term Debt Current	0								0
Long-term Debt Due Within One Year	0				0.1				0	0.1
Long-term Debt - Affiliated	0				32.2				0	32.2
Long-term Debt	0				(0.3)				0	(0.3)
Total Long-term Debt Outstanding	0				32				0	32
Generation and Marketing [Member] | Generation and Marketing Revenues [Member]
Reportable Segment Information
Revenue from Contracts with Customers									1,721.8	1,818.1	1,771.4
Generation and Marketing [Member] | Other Revenues [Member]
Reportable Segment Information
Total Revenues									59.9	22.3
All Other [Member]
Reportable Segment Information
Sales to AEP Affiliates									81.1	75.1	69.7
Total Revenues									95.8	95.1	120.8
Asset Impairments and Other Related Charges									0	19.5	0
Utilities Operating Expense, Depreciation and Amortization									0.6	0.4	0.3
Interest Expense									193.7	122.6	63.9
Income Tax Expense (Benefit)									27.6	21.1	37.4
Equity Earnings (Loss) of Unconsolidated Subsidiaries									0.1	1.2	(2.4)
NET INCOME (LOSS)									(141)	(99.3)	(32.4)
Gross Property Additions									14.5	16.3	15.6
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)	418.4				395.2				418.4	395.2
Accumulated Depreciation and Amortization	184.5				186.6				184.5	186.6
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	233.9				208.6				233.9	208.6
Total Assets	5,440				4,036.5				5,440	4,036.5	3,959.1
Investments in Equity Method Investees	65.4				26.1				65.4	26.1
Affiliated Long Term Debt Current	0								0
Long-term Debt Due Within One Year	501.8				(2)				501.8	(2)
Long-term Debt - Affiliated	0				0				0	0
Long-term Debt	3,122.9				2,268.4				3,122.9	2,268.4
Total Long-term Debt Outstanding	3,624.7				2,266.4				3,624.7	2,266.4
All Other [Member] | Other Revenues [Member]
Reportable Segment Information
Revenue from Contracts with Customers									14.7	20	51.1
Total Revenues									(8.9)	8.9
State Transcos [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Sales to AEP Affiliates									806.7	598.9	568.1
Total Revenues									1,021.4	776.1	706.9
Utilities Operating Expense, Depreciation and Amortization									176	133.9	95.7
Interest Income									1.3	1.3	0.7
Allowance for Equity Funds Used During Construction									84.3	70.6	49
Interest Expense									97.4	83.2	70.2
Income Tax Expense (Benefit)									117.1	83.9	142
NET INCOME (LOSS)									438.6	314.9	270.4
Gross Property Additions									1,419.5	1,570.8	1,522.5
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)	9,893.2				8,268.1				9,893.2	8,268.1
Accumulated Depreciation and Amortization	402.3				271.9				402.3	271.9
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	9,490.9				7,996.2				9,490.9	7,996.2
Notes Receivable, Related Parties	0				0				0	0
Total Assets	9,865				8,406.8				9,865	8,406.8	7,086.9
Total Long-term Debt Outstanding	3,465				2,850				3,465	2,850
State Transcos [Member] | Transmission [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contracts with Customers									214.6	177	138
State Transcos [Member] | Other Revenues [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contracts with Customers									0.1	0.2	0.8
AEPTCo Parent [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Sales to AEP Affiliates									0	0	0
Total Revenues									0	0	0
Utilities Operating Expense, Depreciation and Amortization									0	0	0
Interest Income									123.8	104.6	82.9
Allowance for Equity Funds Used During Construction									0	0	0
Interest Expense									122.1	103.4	82.4
Income Tax Expense (Benefit)									0.3	0.2	0.2
NET INCOME (LOSS)									1.1	1	0.3
Gross Property Additions									0	0	0
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)	0				0				0	0
Accumulated Depreciation and Amortization	0				0				0	0
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	0				0				0	0
Notes Receivable, Related Parties	3,427.3				2,823				3,427.3	2,823
Total Assets	3,519.1				2,857.1				3,519.1	2,857.1	2,590.1
Total Long-term Debt Outstanding	$ 3,427.3				$ 2,823				3,427.3	2,823
AEPTCo Parent [Member] | Transmission [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contracts with Customers									0	0	0
AEPTCo Parent [Member] | Other Revenues [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contracts with Customers									$ 0	$ 0	$ 0

Derivatives and Hedging (Detail

Derivatives and Hedging (Details) gal in Millions, MWh in Millions, MMBTU in Millions	12 Months Ended
	Dec. 31, 2019USD ($)MWhMMBTUgal	Dec. 31, 2018USD ($)MWhMMBTUgal	Dec. 31, 2017USD ($)
Change in Fair Value Recognized in AOCI	$ (69,700,000)	$ 6,600,000	$ 71,200,000
Cash Collateral Netting
Cash Collateral Received Netted Against Risk Management Assets	5,000,000	18,000,000
Cash Collateral Paid Netted Against Risk Management Liabilities	39,000,000	4,000,000
Fair Value of Derivative Instruments
Current Risk Management Assets	172,800,000	162,800,000
Long-term Risk Management Assets	266,600,000	254,000,000
Total Assets	439,400,000	416,800,000
Current Risk Management Liabilities	114,300,000	55,000,000
Long-term Risk Management Liabilities	261,800,000	263,400,000
Total Liabilities	376,100,000	318,400,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	125,000,000	291,300,000	136,000,000
Impact of Fair Value Hedges on the Balance Sheet
Carrying Amount of Hedged Asset (Liability)	(510,800,000)	(478,300,000)
Cumulative Fair Value Hedging Adjustment in the Carrying Amount of the Hedged Asset (Liability)	(14,500,000)	17,400,000
Impact of Cash Flow Hedges on the Balance Sheet
Gain (Loss) on Fair Value Hedging Instruments	31,900,000	(11,300,000)	(4,800,000)
Gain (Loss) on Fair Value Portion of Long Term Debt	(31,900,000)	11,300,000	4,800,000
Collateral Triggering Events
Liabilities for Contracts with Cross Default Provisions Prior to Contractural Netting Arrangements	267,300,000	225,500,000
Amount of Cash Collateral Posted	3,700,000	1,800,000
Additional Settlement Liability if Cross Default Provision is Triggered	246,700,000	181,000,000
AEP Texas Inc. [Member]
Change in Fair Value Recognized in AOCI	1,100,000	(1,000,000)	1,100,000
Fair Value of Derivative Instruments
Current Risk Management Liabilities	0	200,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	300,000	(400,000)	400,000
Appalachian Power Co [Member]
Change in Fair Value Recognized in AOCI	13,400,000	(3,300,000)	11,600,000
Fair Value of Derivative Instruments
Current Risk Management Assets	39,400,000	57,200,000
Long-term Risk Management Assets	100,000	900,000
Current Risk Management Liabilities	1,900,000	400,000
Long-term Risk Management Liabilities	0	200,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	4,100,000	141,100,000	43,200,000
Collateral Triggering Events
Liabilities for Contracts with Cross Default Provisions Prior to Contractural Netting Arrangements	2,300,000	900,000
Amount of Cash Collateral Posted	0	0
Additional Settlement Liability if Cross Default Provision is Triggered	400,000	0
Indiana Michigan Power Co [Member]
Change in Fair Value Recognized in AOCI	800,000	(600,000)	2,800,000
Fair Value of Derivative Instruments
Current Risk Management Assets	9,800,000	8,600,000
Long-term Risk Management Assets	100,000	600,000
Current Risk Management Liabilities	500,000	300,000
Long-term Risk Management Liabilities	0	100,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	25,200,000	11,700,000	14,600,000
Collateral Triggering Events
Liabilities for Contracts with Cross Default Provisions Prior to Contractural Netting Arrangements	1,300,000	500,000
Amount of Cash Collateral Posted	0	0
Additional Settlement Liability if Cross Default Provision is Triggered	200,000	0
Ohio Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Liabilities	7,300,000	5,800,000
Long-term Risk Management Liabilities	96,300,000	93,800,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	6,000,000	25,600,000	(21,800,000)
Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	15,800,000	10,400,000
Current Risk Management Liabilities	0	1,000,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	35,600,000	36,600,000	25,000,000
Southwestern Electric Power Co [Member]
Change in Fair Value Recognized in AOCI	3,700,000	(800,000)	4,700,000
Fair Value of Derivative Instruments
Current Risk Management Assets	6,400,000	4,800,000
Current Risk Management Liabilities	1,900,000	400,000
Long-term Risk Management Liabilities	3,100,000	2,200,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	25,000,000	11,200,000	24,900,000
Collateral Triggering Events
Liabilities for Contracts with Cross Default Provisions Prior to Contractural Netting Arrangements	5,100,000	2,300,000
Amount of Cash Collateral Posted	0	0
Additional Settlement Liability if Cross Default Provision is Triggered	5,100,000	2,300,000
Risk Management Contracts [Member]
Fair Value of Derivative Instruments
Total Assets	408,800,000	382,700,000
Total Liabilities	239,000,000	242,100,000
Risk Management Contracts [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Total Liabilities		200,000
Risk Management Contracts [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	39,500,000	58,100,000
Total Liabilities	1,900,000	600,000
Risk Management Contracts [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	9,900,000	9,200,000
Total Liabilities	500,000	400,000
Risk Management Contracts [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Total Liabilities	103,600,000	99,600,000
Risk Management Contracts [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Total Assets	15,800,000	10,400,000
Total Liabilities	0	1,000,000
Risk Management Contracts [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	6,400,000	4,800,000
Total Liabilities	5,000,000	2,600,000
Commodity [Member]
Impact of Cash Flow Hedges on the Balance Sheet
AOCI Gain (Loss) Net of Tax	(103,500,000)	(23,000,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months	$ (51,700,000)	10,400,000
Derivatives and Hedging (Textuals)
Maximum Length of Time Hedged in Price Risk Cash Flow Hedge	120 months
Cross Default Provisions Maximum Third Party Obligation Amount	$ 50,000,000
Commodity [Member] | Risk Management Contracts [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	513,900,000	397,500,000
Long-term Risk Management Assets	290,800,000	276,400,000
Total Assets	804,700,000	673,900,000
Current Risk Management Liabilities	424,500,000	293,800,000
Long-term Risk Management Liabilities	244,500,000	225,700,000
Total Liabilities	669,000,000	519,500,000
Total MTM Derivative Contract Net Assets (Liabilities)	135,700,000	154,400,000
Commodity [Member] | Risk Management Contracts [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	0	0
Long-term Risk Management Assets	0	0
Total Assets	0	0
Current Risk Management Liabilities	0	700,000
Long-term Risk Management Liabilities	0	0
Total Liabilities	0	700,000
Total MTM Derivative Contract Net Assets (Liabilities)	0	(700,000)
Commodity [Member] | Risk Management Contracts [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	124,400,000	114,400,000
Long-term Risk Management Assets	900,000	3,100,000
Total Assets	125,300,000	117,500,000
Current Risk Management Liabilities	86,200,000	56,700,000
Long-term Risk Management Liabilities	700,000	2,400,000
Total Liabilities	86,900,000	59,100,000
Total MTM Derivative Contract Net Assets (Liabilities)	38,400,000	58,400,000
Commodity [Member] | Risk Management Contracts [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	66,900,000	50,400,000
Long-term Risk Management Assets	500,000	2,000,000
Total Assets	67,400,000	52,400,000
Current Risk Management Liabilities	55,200,000	41,100,000
Long-term Risk Management Liabilities	400,000	1,600,000
Total Liabilities	55,600,000	42,700,000
Total MTM Derivative Contract Net Assets (Liabilities)	11,800,000	9,700,000
Commodity [Member] | Risk Management Contracts [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	0	0
Long-term Risk Management Assets	0	0
Total Assets	0	0
Current Risk Management Liabilities	7,300,000	6,400,000
Long-term Risk Management Liabilities	96,300,000	93,800,000
Total Liabilities	103,600,000	100,200,000
Total MTM Derivative Contract Net Assets (Liabilities)	(103,600,000)	(100,200,000)
Commodity [Member] | Risk Management Contracts [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	16,300,000	10,900,000
Long-term Risk Management Assets	0	0
Total Assets	16,300,000	10,900,000
Current Risk Management Liabilities	500,000	1,700,000
Long-term Risk Management Liabilities	0	0
Total Liabilities	500,000	1,700,000
Total MTM Derivative Contract Net Assets (Liabilities)	15,800,000	9,200,000
Commodity [Member] | Risk Management Contracts [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	6,500,000	5,600,000
Long-term Risk Management Assets	0	0
Total Assets	6,500,000	5,600,000
Current Risk Management Liabilities	2,000,000	1,500,000
Long-term Risk Management Liabilities	3,100,000	2,200,000
Total Liabilities	5,100,000	3,700,000
Total MTM Derivative Contract Net Assets (Liabilities)	1,400,000	1,900,000
Commodity [Member] | Hedging Contracts [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	11,500,000	28,500,000
Long-term Risk Management Assets	11,000,000	16,000,000
Total Assets	22,500,000	44,500,000
Current Risk Management Liabilities	72,300,000	13,200,000
Long-term Risk Management Liabilities	75,700,000	56,100,000
Total Liabilities	148,000,000	69,300,000
Total MTM Derivative Contract Net Assets (Liabilities)	(125,500,000)	(24,800,000)
Interest Rate [Member]
Commodity
Derivative, Notional Amount	625,000,000	500,000,000
Impact of Cash Flow Hedges on the Balance Sheet
AOCI Gain (Loss) Net of Tax	(11,500,000)	(12,600,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months	$ (2,100,000)	(1,100,000)
Derivatives and Hedging (Textuals)
Maximum Length of Time Hedged in Price Risk Cash Flow Hedge	132 months
Interest Rate [Member] | AEP Texas Inc. [Member]
Commodity
Derivative, Notional Amount	$ 0	0
Impact of Cash Flow Hedges on the Balance Sheet
AOCI Gain (Loss) Net of Tax	(3,400,000)	(4,400,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months	(1,100,000)	(1,100,000)
Interest Rate [Member] | Appalachian Power Co [Member]
Commodity
Derivative, Notional Amount	0	0
Impact of Cash Flow Hedges on the Balance Sheet
AOCI Gain (Loss) Net of Tax	900,000	1,800,000
Portion Expected to be Reclassified to Net Income During the Next Twelve Months	900,000	900,000
Interest Rate [Member] | Indiana Michigan Power Co [Member]
Commodity
Derivative, Notional Amount	0	0
Impact of Cash Flow Hedges on the Balance Sheet
AOCI Gain (Loss) Net of Tax	(9,900,000)	(11,500,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months	(1,600,000)	(1,600,000)
Interest Rate [Member] | Ohio Power Co [Member]
Commodity
Derivative, Notional Amount	0	0
Impact of Cash Flow Hedges on the Balance Sheet
AOCI Gain (Loss) Net of Tax	0	1,000,000
Portion Expected to be Reclassified to Net Income During the Next Twelve Months	0	1,000,000
Interest Rate [Member] | Public Service Co Of Oklahoma [Member]
Commodity
Derivative, Notional Amount	0	0
Impact of Cash Flow Hedges on the Balance Sheet
AOCI Gain (Loss) Net of Tax	1,100,000	2,100,000
Portion Expected to be Reclassified to Net Income During the Next Twelve Months	1,000,000	1,000,000
Interest Rate [Member] | Southwestern Electric Power Co [Member]
Commodity
Derivative, Notional Amount	0	0
Impact of Cash Flow Hedges on the Balance Sheet
AOCI Gain (Loss) Net of Tax	(1,800,000)	(3,300,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months	(1,500,000)	(1,500,000)
Interest Rate [Member] | Hedging Contracts [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	6,500,000	0
Long-term Risk Management Assets	12,600,000	0
Total Assets	19,100,000	0
Current Risk Management Liabilities	0	2,000,000
Long-term Risk Management Liabilities	0	15,400,000
Total Liabilities	0	17,400,000
Total MTM Derivative Contract Net Assets (Liabilities)	19,100,000	(17,400,000)
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	531,900,000	426,000,000
Long-term Risk Management Assets	314,400,000	292,400,000
Total Assets	846,300,000	718,400,000
Current Risk Management Liabilities	496,800,000	309,000,000
Long-term Risk Management Liabilities	320,200,000	297,200,000
Total Liabilities	817,000,000	606,200,000
Total MTM Derivative Contract Net Assets (Liabilities)	29,300,000	112,200,000
Gross Amounts Offset in the Statement of Financial Position [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	(359,100,000)	(263,200,000)
Long-term Risk Management Assets	(47,800,000)	(38,400,000)
Total Assets	(406,900,000)	(301,600,000)
Current Risk Management Liabilities	(382,500,000)	(254,000,000)
Long-term Risk Management Liabilities	(58,400,000)	(33,800,000)
Total Liabilities	(440,900,000)	(287,800,000)
Total MTM Derivative Contract Net Assets (Liabilities)	34,000,000	(13,800,000)
Gross Amounts Offset in the Statement of Financial Position [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	0	0
Long-term Risk Management Assets	0	0
Total Assets	0	0
Current Risk Management Liabilities	0	(500,000)
Long-term Risk Management Liabilities	0	0
Total Liabilities	0	(500,000)
Total MTM Derivative Contract Net Assets (Liabilities)	0	500,000
Gross Amounts Offset in the Statement of Financial Position [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	(85,000,000)	(57,200,000)
Long-term Risk Management Assets	(800,000)	(2,200,000)
Total Assets	(85,800,000)	(59,400,000)
Current Risk Management Liabilities	(84,300,000)	(56,300,000)
Long-term Risk Management Liabilities	(700,000)	(2,200,000)
Total Liabilities	(85,000,000)	(58,500,000)
Total MTM Derivative Contract Net Assets (Liabilities)	(800,000)	(900,000)
Gross Amounts Offset in the Statement of Financial Position [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	(57,100,000)	(41,800,000)
Long-term Risk Management Assets	(400,000)	(1,400,000)
Total Assets	(57,500,000)	(43,200,000)
Current Risk Management Liabilities	(54,700,000)	(40,800,000)
Long-term Risk Management Liabilities	(400,000)	(1,500,000)
Total Liabilities	(55,100,000)	(42,300,000)
Total MTM Derivative Contract Net Assets (Liabilities)	(2,400,000)	(900,000)
Gross Amounts Offset in the Statement of Financial Position [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	0	0
Long-term Risk Management Assets	0	0
Total Assets	0	0
Current Risk Management Liabilities	0	(600,000)
Long-term Risk Management Liabilities	0	0
Total Liabilities	0	(600,000)
Total MTM Derivative Contract Net Assets (Liabilities)	0	600,000
Gross Amounts Offset in the Statement of Financial Position [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	(500,000)	(500,000)
Long-term Risk Management Assets	0	0
Total Assets	(500,000)	(500,000)
Current Risk Management Liabilities	(500,000)	(700,000)
Long-term Risk Management Liabilities	0	0
Total Liabilities	(500,000)	(700,000)
Total MTM Derivative Contract Net Assets (Liabilities)	0	200,000
Gross Amounts Offset in the Statement of Financial Position [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	(100,000)	(800,000)
Long-term Risk Management Assets	0	0
Total Assets	(100,000)	(800,000)
Current Risk Management Liabilities	(100,000)	(1,100,000)
Long-term Risk Management Liabilities	0	0
Total Liabilities	(100,000)	(1,100,000)
Total MTM Derivative Contract Net Assets (Liabilities)	0	300,000
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	172,800,000	162,800,000
Long-term Risk Management Assets	266,600,000	254,000,000
Total Assets	439,400,000	416,800,000
Current Risk Management Liabilities	114,300,000	55,000,000
Long-term Risk Management Liabilities	261,800,000	263,400,000
Total Liabilities	376,100,000	318,400,000
Total MTM Derivative Contract Net Assets (Liabilities)	63,300,000	98,400,000
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	0	0
Long-term Risk Management Assets	0	0
Total Assets	0	0
Current Risk Management Liabilities	0	200,000
Long-term Risk Management Liabilities	0	0
Total Liabilities	0	200,000
Total MTM Derivative Contract Net Assets (Liabilities)	0	(200,000)
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	39,400,000	57,200,000
Long-term Risk Management Assets	100,000	900,000
Total Assets	39,500,000	58,100,000
Current Risk Management Liabilities	1,900,000	400,000
Long-term Risk Management Liabilities	0	200,000
Total Liabilities	1,900,000	600,000
Total MTM Derivative Contract Net Assets (Liabilities)	37,600,000	57,500,000
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	9,800,000	8,600,000
Long-term Risk Management Assets	100,000	600,000
Total Assets	9,900,000	9,200,000
Current Risk Management Liabilities	500,000	300,000
Long-term Risk Management Liabilities	0	100,000
Total Liabilities	500,000	400,000
Total MTM Derivative Contract Net Assets (Liabilities)	9,400,000	8,800,000
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	0	0
Long-term Risk Management Assets	0	0
Total Assets	0	0
Current Risk Management Liabilities	7,300,000	5,800,000
Long-term Risk Management Liabilities	96,300,000	93,800,000
Total Liabilities	103,600,000	99,600,000
Total MTM Derivative Contract Net Assets (Liabilities)	(103,600,000)	(99,600,000)
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	15,800,000	10,400,000
Long-term Risk Management Assets	0	0
Total Assets	15,800,000	10,400,000
Current Risk Management Liabilities	0	1,000,000
Long-term Risk Management Liabilities	0	0
Total Liabilities	0	1,000,000
Total MTM Derivative Contract Net Assets (Liabilities)	15,800,000	9,400,000
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	6,400,000	4,800,000
Long-term Risk Management Assets	0	0
Total Assets	6,400,000	4,800,000
Current Risk Management Liabilities	1,900,000	400,000
Long-term Risk Management Liabilities	3,100,000	2,200,000
Total Liabilities	5,000,000	2,600,000
Total MTM Derivative Contract Net Assets (Liabilities)	$ 1,400,000	$ 2,200,000
Power [Member]
Commodity
Derivative, Energy Notional Amount | MWh	365.9	371.1
Power [Member] | AEP Texas Inc. [Member]
Commodity
Derivative, Energy Notional Amount | MWh	0	0
Power [Member] | Appalachian Power Co [Member]
Commodity
Derivative, Energy Notional Amount | MWh	61	66.4
Power [Member] | Indiana Michigan Power Co [Member]
Commodity
Derivative, Energy Notional Amount | MWh	26.8	40.9
Power [Member] | Ohio Power Co [Member]
Commodity
Derivative, Energy Notional Amount | MWh	7.1	7.8
Power [Member] | Public Service Co Of Oklahoma [Member]
Commodity
Derivative, Energy Notional Amount | MWh	14.9	15.2
Power [Member] | Southwestern Electric Power Co [Member]
Commodity
Derivative, Energy Notional Amount | MWh	4.4	4.5
Natural Gas [Member]
Commodity
Derivative, Energy Notional Amount | MMBTU	40.7	87.9
Natural Gas [Member] | AEP Texas Inc. [Member]
Commodity
Derivative, Energy Notional Amount | MMBTU	0	0
Natural Gas [Member] | Appalachian Power Co [Member]
Commodity
Derivative, Energy Notional Amount | MMBTU	0	4
Natural Gas [Member] | Indiana Michigan Power Co [Member]
Commodity
Derivative, Energy Notional Amount | MMBTU	0	2.3
Natural Gas [Member] | Ohio Power Co [Member]
Commodity
Derivative, Energy Notional Amount | MMBTU	0	0
Natural Gas [Member] | Public Service Co Of Oklahoma [Member]
Commodity
Derivative, Energy Notional Amount | MMBTU	0	0
Natural Gas [Member] | Southwestern Electric Power Co [Member]
Commodity
Derivative, Energy Notional Amount | MMBTU	11.6	15.2
Heating Oil and Gasoline [Member]
Commodity
Derivative, Volume Notional Amount | gal	6.9	7.4
Heating Oil and Gasoline [Member] | AEP Texas Inc. [Member]
Commodity
Derivative, Volume Notional Amount | gal	1.8	1.5
Heating Oil and Gasoline [Member] | Appalachian Power Co [Member]
Commodity
Derivative, Volume Notional Amount | gal	1.1	1.4
Heating Oil and Gasoline [Member] | Indiana Michigan Power Co [Member]
Commodity
Derivative, Volume Notional Amount | gal	0.6	0.7
Heating Oil and Gasoline [Member] | Ohio Power Co [Member]
Commodity
Derivative, Volume Notional Amount | gal	1.4	1.8
Heating Oil and Gasoline [Member] | Public Service Co Of Oklahoma [Member]
Commodity
Derivative, Volume Notional Amount | gal	0.7	0.7
Heating Oil and Gasoline [Member] | Southwestern Electric Power Co [Member]
Commodity
Derivative, Volume Notional Amount | gal	0.9	0.8
Interest Rate Contract [Member]
Commodity
Derivative, Notional Amount	$ 140,100,000	$ 37,700,000
Interest Rate Contract [Member] | AEP Texas Inc. [Member]
Commodity
Derivative, Notional Amount	0	0
Interest Rate Contract [Member] | Appalachian Power Co [Member]
Commodity
Derivative, Notional Amount	0	0
Interest Rate Contract [Member] | Indiana Michigan Power Co [Member]
Commodity
Derivative, Notional Amount	0	0
Interest Rate Contract [Member] | Ohio Power Co [Member]
Commodity
Derivative, Notional Amount	0	0
Interest Rate Contract [Member] | Public Service Co Of Oklahoma [Member]
Commodity
Derivative, Notional Amount	0	0
Interest Rate Contract [Member] | Southwestern Electric Power Co [Member]
Commodity
Derivative, Notional Amount	0	0
Vertically Integrated Utilities Revenues [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	700,000	(10,400,000)	6,100,000
Vertically Integrated Utilities Revenues [Member] | AEP Texas Inc. [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	0	0
Vertically Integrated Utilities Revenues [Member] | Appalachian Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	0	0
Vertically Integrated Utilities Revenues [Member] | Indiana Michigan Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	0	0
Vertically Integrated Utilities Revenues [Member] | Ohio Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	0	0
Vertically Integrated Utilities Revenues [Member] | Public Service Co Of Oklahoma [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	0	0
Vertically Integrated Utilities Revenues [Member] | Southwestern Electric Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	0	0
Generation and Marketing Revenues [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	25,100,000	38,900,000	42,800,000
Generation and Marketing Revenues [Member] | AEP Texas Inc. [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	0	0
Generation and Marketing Revenues [Member] | Appalachian Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	0	0
Generation and Marketing Revenues [Member] | Indiana Michigan Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	0	0
Generation and Marketing Revenues [Member] | Ohio Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	0	0
Generation and Marketing Revenues [Member] | Public Service Co Of Oklahoma [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	0	0
Generation and Marketing Revenues [Member] | Southwestern Electric Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	0	0
Electric Generation, Transmission and Distribution Revenues [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	0	0
Electric Generation, Transmission and Distribution Revenues [Member] | AEP Texas Inc. [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	0	0
Electric Generation, Transmission and Distribution Revenues [Member] | Appalachian Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	100,000	(1,900,000)	600,000
Electric Generation, Transmission and Distribution Revenues [Member] | Indiana Michigan Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	500,000	(8,200,000)	5,300,000
Electric Generation, Transmission and Distribution Revenues [Member] | Ohio Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	0	0
Electric Generation, Transmission and Distribution Revenues [Member] | Public Service Co Of Oklahoma [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	0	0
Electric Generation, Transmission and Distribution Revenues [Member] | Southwestern Electric Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	100,000	100,000	100,000
Purchased Electricity for Resale [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	1,900,000	8,600,000	5,600,000
Purchased Electricity for Resale [Member] | AEP Texas Inc. [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	0	0
Purchased Electricity for Resale [Member] | Appalachian Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	1,600,000	7,600,000	2,000,000
Purchased Electricity for Resale [Member] | Indiana Michigan Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	100,000	800,000	600,000
Purchased Electricity for Resale [Member] | Ohio Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	0	0
Purchased Electricity for Resale [Member] | Public Service Co Of Oklahoma [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	0	0
Purchased Electricity for Resale [Member] | Southwestern Electric Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	0	0
Other Operation Expense [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	(800,000)	1,700,000	800,000
Other Operation Expense [Member] | AEP Texas Inc. [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	(200,000)	400,000	100,000
Other Operation Expense [Member] | Appalachian Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	(100,000)	200,000	100,000
Other Operation Expense [Member] | Indiana Michigan Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	(100,000)	200,000	100,000
Other Operation Expense [Member] | Ohio Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	(200,000)	300,000	100,000
Other Operation Expense [Member] | Public Service Co Of Oklahoma [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	(100,000)	200,000	100,000
Other Operation Expense [Member] | Southwestern Electric Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	(100,000)	200,000	100,000
Maintenance Expense [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	(800,000)	1,900,000	700,000
Maintenance Expense [Member] | AEP Texas Inc. [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	(200,000)	400,000	200,000
Maintenance Expense [Member] | Appalachian Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	(200,000)	400,000	100,000
Maintenance Expense [Member] | Indiana Michigan Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	(100,000)	200,000	100,000
Maintenance Expense [Member] | Ohio Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	(200,000)	400,000	100,000
Maintenance Expense [Member] | Public Service Co Of Oklahoma [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	(100,000)	200,000	100,000
Maintenance Expense [Member] | Southwestern Electric Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	(100,000)	200,000	100,000
Regulatory Assets [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	(3,700,000)	27,900,000	(29,400,000)
Regulatory Assets [Member] | AEP Texas Inc. [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	700,000	(700,000)	0
Regulatory Assets [Member] | Appalachian Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	300,000	(700,000)	0
Regulatory Assets [Member] | Indiana Michigan Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	300,000	7,100,000	(7,400,000)
Regulatory Assets [Member] | Ohio Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	(3,700,000)	24,900,000	(22,000,000)
Regulatory Assets [Member] | Public Service Co Of Oklahoma [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	1,200,000	(1,100,000)	0
Regulatory Assets [Member] | Southwestern Electric Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	(1,500,000)	(1,200,000)	300,000
Regulatory Liabilities [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	102,600,000	222,700,000	109,400,000
Regulatory Liabilities [Member] | AEP Texas Inc. [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	0	(500,000)	100,000
Regulatory Liabilities [Member] | Appalachian Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	2,400,000	135,500,000	40,400,000
Regulatory Liabilities [Member] | Indiana Michigan Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	24,500,000	11,600,000	15,900,000
Regulatory Liabilities [Member] | Ohio Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	10,100,000	0	0
Regulatory Liabilities [Member] | Public Service Co Of Oklahoma [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	34,600,000	37,300,000	24,800,000
Regulatory Liabilities [Member] | Southwestern Electric Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	26,600,000	11,900,000	24,300,000
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Commodity [Member]
Change in Fair Value Recognized in AOCI	(127,200,000)	37,300,000	(20,400,000)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Commodity [Member] | Appalachian Power Co [Member]
Change in Fair Value Recognized in AOCI		(700,000)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Interest Rate [Member]
Change in Fair Value Recognized in AOCI	(200,000)	2,300,000	1,600,000
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Interest Rate [Member] | AEP Texas Inc. [Member]
Change in Fair Value Recognized in AOCI	0	0	0
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Interest Rate [Member] | Appalachian Power Co [Member]
Change in Fair Value Recognized in AOCI	0	0	0
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Interest Rate [Member] | Indiana Michigan Power Co [Member]
Change in Fair Value Recognized in AOCI	0	0	0
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Interest Rate [Member] | Ohio Power Co [Member]
Change in Fair Value Recognized in AOCI	0	0	0
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Interest Rate [Member] | Public Service Co Of Oklahoma [Member]
Change in Fair Value Recognized in AOCI	0	0	0
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Interest Rate [Member] | Southwestern Electric Power Co [Member]
Change in Fair Value Recognized in AOCI	0	2,300,000	$ 0
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Apple Blossom and Black Oak [Member] | Interest Rate [Member]
Change in Fair Value Recognized in AOCI	4,000,000
Fair Value, Inputs, Level 3 [Member]
Fair Value of Derivative Instruments
Total Assets	372,400,000	353,600,000
Total Liabilities	262,500,000	222,400,000
Fair Value, Inputs, Level 3 [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	40,500,000	58,300,000
Total Liabilities	2,800,000	500,000
Fair Value, Inputs, Level 3 [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	8,000,000	10,300,000
Total Liabilities	2,200,000	1,400,000
Fair Value, Inputs, Level 3 [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	6,500,000	5,600,000
Total Liabilities	5,100,000	3,300,000
Fair Value, Inputs, Level 3 [Member] | Risk Management Contracts [Member]
Fair Value of Derivative Instruments
Total Assets	369,200,000	340,900,000
Total Liabilities	224,000,000	185,600,000
Fair Value, Inputs, Level 3 [Member] | Risk Management Contracts [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Total Liabilities		0
Fair Value, Inputs, Level 3 [Member] | Risk Management Contracts [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	40,500,000	58,300,000
Total Liabilities	2,800,000	500,000
Fair Value, Inputs, Level 3 [Member] | Risk Management Contracts [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	8,000,000	10,300,000
Total Liabilities	2,200,000	1,400,000
Fair Value, Inputs, Level 3 [Member] | Risk Management Contracts [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Total Liabilities	103,600,000	99,400,000
Fair Value, Inputs, Level 3 [Member] | Risk Management Contracts [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Total Assets	16,300,000	10,800,000
Total Liabilities	500,000	1,300,000
Fair Value, Inputs, Level 3 [Member] | Risk Management Contracts [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	6,500,000	5,600,000
Total Liabilities	5,100,000	3,300,000
Fair Value, Inputs, Level 3 [Member] | Maturity Period 5 [Member]
Maturity Of Net Fair Value Of Risk Management Contracts Prior To Cash Collateral Assets Or Liabilities		23,000,000
Fair Value, Inputs, Level 3 [Member] | Maturity Period Eight [Member]
Maturity Of Net Fair Value Of Risk Management Contracts Prior To Cash Collateral Assets Or Liabilities	(12,000,000)
Fair Value, Inputs, Level 3 [Member] | 2024-2025 [Member]
Maturity Of Net Fair Value Of Risk Management Contracts Prior To Cash Collateral Assets Or Liabilities	25,000,000
Fair Value, Inputs, Level 3 [Member] | Maturity Period Seven [Member]
Maturity Of Net Fair Value Of Risk Management Contracts Prior To Cash Collateral Assets Or Liabilities		(12,000,000)
Fair Value, Inputs, Level 2 [Member]
Fair Value of Derivative Instruments
Total Assets	474,200,000	350,600,000
Total Liabilities	555,300,000	369,200,000
Fair Value, Inputs, Level 2 [Member] | Risk Management Contracts [Member]
Fair Value of Derivative Instruments
Total Assets	440,100,000	326,500,000
Total Liabilities	450,000,000	327,000,000
Fair Value, Inputs, Level 2 [Member] | Risk Management Contracts [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Total Liabilities		700,000
Fair Value, Inputs, Level 2 [Member] | Risk Management Contracts [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	84,600,000	59,100,000
Total Liabilities	84,000,000	58,400,000
Fair Value, Inputs, Level 2 [Member] | Risk Management Contracts [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	59,500,000	42,100,000
Total Liabilities	53,400,000	41,200,000
Fair Value, Inputs, Level 2 [Member] | Risk Management Contracts [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Total Liabilities	0	800,000
Fair Value, Inputs, Level 2 [Member] | Risk Management Contracts [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Total Assets	0	0
Total Liabilities	0	300,000
Fair Value, Inputs, Level 2 [Member] | Risk Management Contracts [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	0	0
Total Liabilities	$ 0	400,000
Fair Value, Inputs, Level 2 [Member] | Maturity Period 5 [Member]
Maturity Of Net Fair Value Of Risk Management Contracts Prior To Cash Collateral Assets Or Liabilities		1,000,000
Fair Value, Inputs, Level 2 [Member] | Maturity Period Seven [Member]
Maturity Of Net Fair Value Of Risk Management Contracts Prior To Cash Collateral Assets Or Liabilities		$ 1,000,000

Fair Value Long-term Debt, Othe

Fair Value Long-term Debt, Other Temporary Investments, Nuclear Trusts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	$ 26,725.5		$ 23,346.7
Long-term Debt, Fair Value	30,172		24,093.9
Other Temporary Investments
Cost	367.1		355
Gross Unrealized Gains	21.4		16.4
Gross Unrealized Losses	0		(2.3)
Fair Value	388.5		369.1
Debt and Equity Securities Within Other Temporary Investments
Proceeds From Investment Sales	21.2		0	$ 0
Purchases of Investments	45		3.1	14.2
Gross Realized Gains on Investment Sales	0		0	0
Gross Realized Losses on Investment Sales	0.4		0	0
Nuclear Trust Fund Investments
Fair Value	2,975.7		2,474.9
Contractual Maturities, Fair Value of Debt Securities
Fair Value	2,975.7		2,474.9
Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains	1,205.9		794.7
Other-Than-Temporary Impairments	(7.9)		(9.2)
Securities Activity Within the Decommissioning and SNF Trusts
Proceeds from Investment Sales	1,473		2,010	2,256.3
Purchases of Investments	1,531		2,064.7	2,300.5
Gross Realized Gains on Investment Sales	76.5		47.5	200.7
Gross Realized Losses on Investment Sales	24.3		32.8	146
Contractual Maturities, Fair Value of Debt Securities
Within 1 year	371
After 1 year through 5 years	386.2
After 5 years through 10 years	217.3
After 10 years	218
Fair Value Measurements (Textuals)
Adjusted Cost of Debt Securities	1,100		1,000
Adjusted Cost of Domestic Equity Securities	623		629
AEP Texas Inc. [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	4,558.4		3,881.3
Long-term Debt, Fair Value	4,981.5		3,964.6
AEP Transmission Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	3,427.3		2,823
Long-term Debt, Fair Value	3,868		2,782.4
Appalachian Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	4,363.8		4,062.6
Long-term Debt, Fair Value	5,253.1		4,473.3
Indiana Michigan Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	3,050.2		3,035.4
Long-term Debt, Fair Value	3,453.8		3,070.2
Nuclear Trust Fund Investments
Fair Value	2,975.7		2,474.9
Contractual Maturities, Fair Value of Debt Securities
Fair Value	2,975.7		2,474.9
Indiana Michigan Power Co [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains	1,205.9		794.7
Other-Than-Temporary Impairments	(7.9)		(9.2)
Securities Activity Within the Decommissioning and SNF Trusts
Proceeds from Investment Sales	1,473		2,010	2,256.3
Purchases of Investments	1,531		2,064.7	2,300.5
Gross Realized Gains on Investment Sales	76.5		47.5	200.7
Gross Realized Losses on Investment Sales	24.3		32.8	$ 146
Contractual Maturities, Fair Value of Debt Securities
Within 1 year	371
After 1 year through 5 years	386.2
After 5 years through 10 years	217.3
After 10 years	218
Fair Value Measurements (Textuals)
Adjusted Cost of Debt Securities	1,100		1,000
Adjusted Cost of Domestic Equity Securities	623		629
Ohio Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	2,082		1,716.6
Long-term Debt, Fair Value	2,554.3		1,919.7
Public Service Co Of Oklahoma [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	1,386.2		1,287
Long-term Debt, Fair Value	1,603.3		1,361.9
Southwestern Electric Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	2,655.6		2,713.4
Long-term Debt, Fair Value	2,927.9		2,670.2
Cash [Member]
Other Temporary Investments
Cost	214.7		230.6
Gross Unrealized Gains	0		0
Gross Unrealized Losses	0		0
Fair Value	214.7		230.6
Fixed Income Funds [Member]
Nuclear Trust Fund Investments
Fair Value	1,192.5		1,057.1
Contractual Maturities, Fair Value of Debt Securities
Fair Value	1,192.5		1,057.1
Fixed Income Funds [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains	61.5		28.4
Other-Than-Temporary Impairments	(7.9)		(9.2)
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments
Fair Value	1,192.5		1,057.1
Contractual Maturities, Fair Value of Debt Securities
Fair Value	1,192.5		1,057.1
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains	61.5		28.4
Other-Than-Temporary Impairments	(7.9)		(9.2)
Mutual Funds Fixed Income [Member]
Other Temporary Investments
Cost	123.2		106.6
Gross Unrealized Gains	0.1		0
Gross Unrealized Losses	0		(2.3)
Fair Value	123.3		104.3
Domestic [Member]
Nuclear Trust Fund Investments
Fair Value	1,767.9		1,395.3
Contractual Maturities, Fair Value of Debt Securities
Fair Value	1,767.9		1,395.3
Domestic [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Unrealized Gain on Securities	1,100		784
Unrealized Loss on Securities	5		18
Nuclear Trust Fund Investments
Gross Unrealized Gains	1,144.4		766.3
Other-Than-Temporary Impairments	0		0
Domestic [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments
Fair Value	1,767.9		1,395.3
Contractual Maturities, Fair Value of Debt Securities
Fair Value	1,767.9		1,395.3
Domestic [Member] | Indiana Michigan Power Co [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Unrealized Gain on Securities	1,100		784
Unrealized Loss on Securities	5		18
Nuclear Trust Fund Investments
Gross Unrealized Gains	1,144.4	[1]	766.3
Other-Than-Temporary Impairments	0	[1]	0
Mutual Funds Equity [Member]
Other Temporary Investments
Cost	29.2		17.8
Gross Unrealized Gains	21.3		16.4
Gross Unrealized Losses	0		0
Fair Value	50.5		34.2
Cash and Cash Equivalents [Member]
Nuclear Trust Fund Investments
Fair Value	15.3		22.5
Contractual Maturities, Fair Value of Debt Securities
Fair Value	15.3		22.5
Cash and Cash Equivalents [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains	0		0
Other-Than-Temporary Impairments	0		0
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments
Fair Value	15.3		22.5
Contractual Maturities, Fair Value of Debt Securities
Fair Value	15.3		22.5
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains	0		0
Other-Than-Temporary Impairments	0		0
US Government Agencies Debt Securities [Member]
Nuclear Trust Fund Investments
Fair Value	1,112.5		996.1
Contractual Maturities, Fair Value of Debt Securities
Fair Value	1,112.5		996.1
US Government Agencies Debt Securities [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains	55.5		26.7
Other-Than-Temporary Impairments	(6.1)		(7.1)
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments
Fair Value	1,112.5		996.1
Contractual Maturities, Fair Value of Debt Securities
Fair Value	1,112.5		996.1
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains	55.5		26.7
Other-Than-Temporary Impairments	(6.1)		(7.1)
Corporate Debt [Member]
Nuclear Trust Fund Investments
Fair Value	72.4		52.4
Contractual Maturities, Fair Value of Debt Securities
Fair Value	72.4		52.4
Corporate Debt [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains	5.3		1.1
Other-Than-Temporary Impairments	(1.6)		(1.9)
Corporate Debt [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments
Fair Value	72.4		52.4
Contractual Maturities, Fair Value of Debt Securities
Fair Value	72.4		52.4
Corporate Debt [Member] | Indiana Michigan Power Co [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains	5.3		1.1
Other-Than-Temporary Impairments	(1.6)		(1.9)
State and Local Jurisdiction [Member]
Nuclear Trust Fund Investments
Fair Value	7.6		8.6
Contractual Maturities, Fair Value of Debt Securities
Fair Value	7.6		8.6
State and Local Jurisdiction [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains	0.7		0.6
Other-Than-Temporary Impairments	(0.2)		(0.2)
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments
Fair Value	7.6		8.6
Contractual Maturities, Fair Value of Debt Securities
Fair Value	7.6		8.6
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains	0.7		0.6
Other-Than-Temporary Impairments	(0.2)		$ (0.2)
Equity units [Member]
Book Values and Fair Values of Long - term Debt
Long-term Debt, Fair Value	$ 871
[1]	Amount reported as Gross Unrealized Gains includes unrealized gains of $1.1 billion and $784 million and unrealized losses of $5 million and $18 million as of December 31, 2019 and 2018 , respectively. AEP adopted ASU 2016-01 during the first quarter of 2018 by means of a modified retrospective approach. Due to the adoption of the ASU, Other-Than-Temporary Impairments are no longer applicable to Equity Securities with readily determinable fair values.

Fair Value Financial Assets Lia

Fair Value Financial Assets Liabilities (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets, Fair Value Disclosure
Other Temporary Investments	$ 388,500,000	$ 369,100,000
Risk Management Assets
Risk Management Assets	439,400,000	416,800,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	2,975,700,000	2,474,900,000
Total Assets	3,803,600,000	3,260,800,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	376,100,000	318,400,000
Changes in the Fair Value of Net Trading Derivatives and Other Investments
Beginning Balance	131,200,000	40,300,000	$ 2,500,000
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	15,800,000	148,900,000	37,300,000
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	(100,000)	9,800,000	33,600,000
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	(15,100,000)	15,700,000	(18,800,000)
Settlements	(117,600,000)	(214,000,000)	(50,600,000)
Transfers into Level 3	(600,000)	15,800,000	16,200,000
Transfers out of Level 3	35,600,000	(1,600,000)	(10,100,000)
Changes in Fair Value Allocated to Regulated Jurisdiction	60,700,000	116,300,000	30,200,000
Ending Balance	109,900,000	131,200,000	40,300,000
Other [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	17,100,000	9,100,000
Risk Management Assets
Risk Management Assets	(411,200,000)	(291,200,000)
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	8,600,000	10,200,000
Total Assets	(385,500,000)	(271,900,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities	(445,500,000)	(277,400,000)
Level 1 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	371,400,000	360,000,000
Risk Management Assets
Risk Management Assets	4,000,000	3,800,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	1,774,600,000	1,407,600,000
Total Assets	2,150,000,000	1,771,400,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	3,800,000	4,200,000
Level 2 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	0	0
Risk Management Assets
Risk Management Assets	474,200,000	350,600,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	1,192,500,000	1,057,100,000
Total Assets	1,666,700,000	1,407,700,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	555,300,000	369,200,000
Level 3 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	0	0
Risk Management Assets
Risk Management Assets	372,400,000	353,600,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Total Assets	372,400,000	353,600,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	262,500,000	222,400,000
2019 [Member] | Level 2 [Member]
Fair Value Measurements 1 (Textuals)
Maturity Of Net Fair Value Of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		(4,000,000)
2019 [Member] | Level 3 [Member]
Fair Value Measurements 1 (Textuals)
Maturity Of Net Fair Value Of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		108,000,000
2020 [Member] | Level 2 [Member]
Fair Value Measurements 1 (Textuals)
Maturity Of Net Fair Value Of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities	(7,000,000)
2020 [Member] | Level 3 [Member]
Fair Value Measurements 1 (Textuals)
Maturity Of Net Fair Value Of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities	96,000,000
2020 - 2022 [Member] | Level 2 [Member]
Fair Value Measurements 1 (Textuals)
Maturity Of Net Fair Value Of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		1,000,000
2020 - 2022 [Member] | Level 3 [Member]
Fair Value Measurements 1 (Textuals)
Maturity Of Net Fair Value Of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		37,000,000
2021 - 2023 [Member] | Level 2 [Member]
Fair Value Measurements 1 (Textuals)
Maturity Of Net Fair Value Of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities	(3,000,000)
2021 - 2023 [Member] | Level 3 [Member]
Fair Value Measurements 1 (Textuals)
Maturity Of Net Fair Value Of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities	36,000,000
2023 - 2024 [Member] | Level 2 [Member]
Fair Value Measurements 1 (Textuals)
Maturity Of Net Fair Value Of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		1,000,000
2023 - 2024 [Member] | Level 3 [Member]
Fair Value Measurements 1 (Textuals)
Maturity Of Net Fair Value Of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		23,000,000
2024-2025 [Member] | Level 3 [Member]
Fair Value Measurements 1 (Textuals)
Maturity Of Net Fair Value Of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities	25,000,000
2025 - 2032 [Member] | Level 2 [Member]
Fair Value Measurements 1 (Textuals)
Maturity Of Net Fair Value Of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		1,000,000
2025 - 2032 [Member] | Level 3 [Member]
Fair Value Measurements 1 (Textuals)
Maturity Of Net Fair Value Of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		(12,000,000)
2026 - 2032 [Member] | Level 3 [Member]
Fair Value Measurements 1 (Textuals)
Maturity Of Net Fair Value Of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities	(12,000,000)
Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	408,800,000	382,700,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	239,000,000	242,100,000
Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	(404,500,000)	(288,500,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities	(438,800,000)	(274,700,000)
Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	4,000,000	3,800,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	3,800,000	4,200,000
Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	440,100,000	326,500,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	450,000,000	327,000,000
Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	369,200,000	340,900,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	224,000,000	185,600,000
Energy Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	296,700,000	257,100,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	249,300,000	212,500,000
Energy Contracts [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	(0.05)	(0.05)
Energy Contracts [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	177.30	176.57
Energy Contracts [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	31.31	33.07
Natural Gas Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	0	0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	4,900,000	2,500,000
Natural Gas Contracts [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	1.89	2.18
Natural Gas Contracts [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	2.51	3.54
Natural Gas Contracts [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	2.19	2.47
FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	75,700,000	96,500,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	8,300,000	7,400,000
FTRs [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	(8.52)	(11.68)
FTRs [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	9.34	17.79
FTRs [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	0.42	1.09
Commodity Hedges [Member]
Risk Management Assets
Risk Management Assets	11,500,000	34,100,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	137,100,000	58,900,000
Commodity Hedges [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	(6,700,000)	(2,700,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities	(6,700,000)	(2,700,000)
Commodity Hedges [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	0	0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	0	0
Commodity Hedges [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	15,000,000	24,100,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	105,300,000	24,800,000
Commodity Hedges [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	3,200,000	12,700,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	38,500,000	36,800,000
Interest Rate Foreign Currency Hedges [Member]
Risk Management Assets
Risk Management Assets	4,600,000
Interest Rate Foreign Currency Hedges [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	0
Interest Rate Foreign Currency Hedges [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	0
Interest Rate Foreign Currency Hedges [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	4,600,000
Interest Rate Foreign Currency Hedges [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	0
Fair Value Hedges [Member]
Risk Management Assets
Risk Management Assets	14,500,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		17,400,000
Fair Value Hedges [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		0
Fair Value Hedges [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		0
Fair Value Hedges [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	14,500,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		17,400,000
Fair Value Hedges [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		0
AEP Texas Inc. [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents	154,700,000	156,700,000
AEP Texas Inc. [Member] | Other [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents	0	0
AEP Texas Inc. [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents	154,700,000	156,700,000
AEP Texas Inc. [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents	0	0
AEP Texas Inc. [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents	0	0
AEP Texas Inc. [Member] | Risk Management Commodity Contracts [Member]
Liabilities, Fair Value Disclosure
Risk Management Liabilities		200,000
AEP Texas Inc. [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Liabilities, Fair Value Disclosure
Risk Management Liabilities		(500,000)
AEP Texas Inc. [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Liabilities, Fair Value Disclosure
Risk Management Liabilities		0
AEP Texas Inc. [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Liabilities, Fair Value Disclosure
Risk Management Liabilities		700,000
AEP Texas Inc. [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Liabilities, Fair Value Disclosure
Risk Management Liabilities		0
Appalachian Power Co [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents	23,500,000	25,600,000
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets	63,000,000	83,700,000
Changes in the Fair Value of Net Trading Derivatives and Other Investments
Beginning Balance	57,800,000	24,700,000	1,400,000
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	(13,900,000)	104,100,000	17,200,000
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	0	0	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	0	0	0
Settlements	(42,500,000)	(127,900,000)	(18,900,000)
Transfers into Level 3	(500,000)	0	0
Transfers out of Level 3	(700,000)	0	0
Changes in Fair Value Allocated to Regulated Jurisdiction	37,500,000	56,900,000	25,000,000
Ending Balance	37,700,000	57,800,000	24,700,000
Appalachian Power Co [Member] | Other [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents	0	0
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets	(85,600,000)	(59,400,000)
Appalachian Power Co [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents	23,500,000	25,600,000
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets	23,500,000	25,700,000
Appalachian Power Co [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents	0	0
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets	84,600,000	59,100,000
Appalachian Power Co [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents	0	0
Risk Management Assets
Risk Management Assets	40,500,000	58,300,000
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets	40,500,000	58,300,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	2,800,000	500,000
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	39,500,000	58,100,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	1,900,000	600,000
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	(85,600,000)	(59,400,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities	(84,900,000)	(58,500,000)
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	0	100,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	0	200,000
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	84,600,000	59,100,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	84,000,000	58,400,000
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	40,500,000	58,300,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	2,800,000	500,000
Appalachian Power Co [Member] | Energy Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	5,700,000	2,400,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	2,600,000	500,000
Appalachian Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	12.70	16.82
Appalachian Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	41.20	62.65
Appalachian Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	25.92	37
Appalachian Power Co [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	34,800,000	55,900,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	200,000	0
Appalachian Power Co [Member] | FTRs [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	(0.14)	0.10
Appalachian Power Co [Member] | FTRs [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	7.08	15.16
Appalachian Power Co [Member] | FTRs [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	1.70	3.27
Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	2,975,700,000	2,474,900,000
Total Assets	2,985,600,000	2,484,100,000
Changes in the Fair Value of Net Trading Derivatives and Other Investments
Beginning Balance	8,900,000	7,600,000	2,800,000
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	4,700,000	14,200,000	4,000,000
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	0	0	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	0	0	0
Settlements	(13,000,000)	(21,300,000)	(7,100,000)
Transfers into Level 3	(300,000)	0	0
Transfers out of Level 3	(400,000)	(300,000)	0
Changes in Fair Value Allocated to Regulated Jurisdiction	5,900,000	8,700,000	7,900,000
Ending Balance	5,800,000	8,900,000	7,600,000
Indiana Michigan Power Co [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	8,600,000	10,200,000
Total Assets	(49,000,000)	(33,000,000)
Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	1,774,600,000	1,407,600,000
Total Assets	1,774,600,000	1,407,600,000
Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	1,192,500,000	1,057,100,000
Total Assets	1,252,000,000	1,099,200,000
Indiana Michigan Power Co [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	8,000,000	10,300,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Total Assets	8,000,000	10,300,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	2,200,000	1,400,000
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	9,900,000	9,200,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	500,000	400,000
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	(57,600,000)	(43,200,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities	(55,100,000)	(42,300,000)
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	0	0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	0	100,000
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	59,500,000	42,100,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	53,400,000	41,200,000
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	8,000,000	10,300,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	2,200,000	1,400,000
Indiana Michigan Power Co [Member] | Energy Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	3,400,000	1,400,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	1,500,000	900,000
Indiana Michigan Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	12.70	16.82
Indiana Michigan Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	41.20	62.65
Indiana Michigan Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	25.92	37
Indiana Michigan Power Co [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	4,600,000	8,900,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	700,000	500,000
Indiana Michigan Power Co [Member] | FTRs [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	(0.75)	(2.11)
Indiana Michigan Power Co [Member] | FTRs [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	4.07	6.21
Indiana Michigan Power Co [Member] | FTRs [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	0.74	1.06
Ohio Power Co [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		27,600,000
Changes in the Fair Value of Net Trading Derivatives and Other Investments
Beginning Balance	(99,400,000)	(132,400,000)	(119,000,000)
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	(900,000)	1,800,000	(1,400,000)
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	0	0	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	0	0	0
Settlements	6,600,000	4,600,000	7,400,000
Transfers into Level 3	0	0	0
Transfers out of Level 3	0	0	0
Changes in Fair Value Allocated to Regulated Jurisdiction	(9,900,000)	26,600,000	(19,400,000)
Ending Balance	(103,600,000)	(99,400,000)	(132,400,000)
Ohio Power Co [Member] | Other [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0
Ohio Power Co [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		27,600,000
Ohio Power Co [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0
Ohio Power Co [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	103,600,000	99,600,000
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	0	(600,000)
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	0	0
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	0	800,000
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	103,600,000	99,400,000
Ohio Power Co [Member] | Energy Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	0	0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	103,600,000	99,400,000
Ohio Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	29.23	26.29
Ohio Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	61.43	62.74
Ohio Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	42.46	42.50
Public Service Co Of Oklahoma [Member]
Changes in the Fair Value of Net Trading Derivatives and Other Investments
Beginning Balance	9,500,000	6,200,000	700,000
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	13,500,000	18,100,000	3,100,000
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	0	0	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	0	0	0
Settlements	(23,000,000)	(24,300,000)	(3,800,000)
Transfers into Level 3	0	0	0
Transfers out of Level 3	0	0	0
Changes in Fair Value Allocated to Regulated Jurisdiction	15,800,000	9,500,000	6,200,000
Ending Balance	15,800,000	9,500,000	6,200,000
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	15,800,000	10,400,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	0	1,000,000
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	(500,000)	(400,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities	(500,000)	(600,000)
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	0	0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	0	0
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	0	0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	0	300,000
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	16,300,000	10,800,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	500,000	1,300,000
Public Service Co Of Oklahoma [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	16,300,000	10,800,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	500,000	1,300,000
Public Service Co Of Oklahoma [Member] | FTRs [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	(8.52)	(11.68)
Public Service Co Of Oklahoma [Member] | FTRs [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	0.85	10.30
Public Service Co Of Oklahoma [Member] | FTRs [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	(2.31)	(1.40)
Southwestern Electric Power Co [Member]
Changes in the Fair Value of Net Trading Derivatives and Other Investments
Beginning Balance	2,300,000	5,900,000	700,000
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	6,000,000	(4,800,000)	6,000,000
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	0	0	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	0	0	0
Settlements	(9,600,000)	(2,100,000)	(6,800,000)
Transfers into Level 3	0	0	0
Transfers out of Level 3	0	0	0
Changes in Fair Value Allocated to Regulated Jurisdiction	2,700,000	3,300,000	6,000,000
Ending Balance	1,400,000	2,300,000	$ 5,900,000
Southwestern Electric Power Co [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	6,500,000	5,600,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	5,100,000	3,300,000
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	6,400,000	4,800,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	5,000,000	2,600,000
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	(100,000)	(800,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities	(100,000)	(1,100,000)
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	0	0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	0	0
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	0	0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	0	400,000
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	6,500,000	5,600,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	5,100,000	3,300,000
Southwestern Electric Power Co [Member] | Natural Gas Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	0	0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	4,900,000	2,500,000
Southwestern Electric Power Co [Member] | Natural Gas Contracts [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	1.89	2.18
Southwestern Electric Power Co [Member] | Natural Gas Contracts [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	2.51	3.54
Southwestern Electric Power Co [Member] | Natural Gas Contracts [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	2.18	2.47
Southwestern Electric Power Co [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	6,500,000	5,600,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	200,000	800,000
Southwestern Electric Power Co [Member] | FTRs [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	(8.52)	(11.68)
Southwestern Electric Power Co [Member] | FTRs [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	0.85	10.30
Southwestern Electric Power Co [Member] | FTRs [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	(2.31)	(1.40)
Cash [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	214,700,000	230,600,000
Cash [Member] | Other [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	17,100,000	9,100,000
Cash [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	197,600,000	221,500,000
Cash [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	0	0
Cash [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	0	0
Mutual Funds Fixed Income [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	123,300,000	104,300,000
Mutual Funds Fixed Income [Member] | Other [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	0	0
Mutual Funds Fixed Income [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	123,300,000	104,300,000
Mutual Funds Fixed Income [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	0	0
Mutual Funds Fixed Income [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	0	0
Mutual Funds Equity [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	50,500,000	34,200,000
Mutual Funds Equity [Member] | Other [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	0	0
Mutual Funds Equity [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	50,500,000	34,200,000
Mutual Funds Equity [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	0	0
Mutual Funds Equity [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	0	0
Cash and Cash Equivalents [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	15,300,000	22,500,000
Cash and Cash Equivalents [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	8,600,000	10,200,000
Cash and Cash Equivalents [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	6,700,000	12,300,000
Cash and Cash Equivalents [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Cash and Cash Equivalents [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	15,300,000	22,500,000
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	8,600,000	10,200,000
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	6,700,000	12,300,000
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
US Government Agencies Debt Securities [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	1,112,500,000	996,100,000
US Government Agencies Debt Securities [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
US Government Agencies Debt Securities [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
US Government Agencies Debt Securities [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	1,112,500,000	996,100,000
US Government Agencies Debt Securities [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	1,112,500,000	996,100,000
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	1,112,500,000	996,100,000
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Corporate Debt Securities [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	72,400,000	52,400,000
Corporate Debt Securities [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Corporate Debt Securities [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Corporate Debt Securities [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	72,400,000	52,400,000
Corporate Debt Securities [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Corporate Debt Securities [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	72,400,000	52,400,000
Corporate Debt Securities [Member] | Indiana Michigan Power Co [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Corporate Debt Securities [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Corporate Debt Securities [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	72,400,000	52,400,000
Corporate Debt Securities [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
State and Local Jurisdiction [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	7,600,000	8,600,000
State and Local Jurisdiction [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
State and Local Jurisdiction [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
State and Local Jurisdiction [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	7,600,000	8,600,000
State and Local Jurisdiction [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	7,600,000	8,600,000
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	7,600,000	8,600,000
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Fixed Income Funds [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	1,192,500,000	1,057,100,000
Fixed Income Funds [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Fixed Income Funds [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Fixed Income Funds [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	1,192,500,000	1,057,100,000
Fixed Income Funds [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	1,192,500,000	1,057,100,000
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	1,192,500,000	1,057,100,000
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Domestic [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	1,767,900,000	1,395,300,000
Domestic [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Domestic [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	1,767,900,000	1,395,300,000
Domestic [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Domestic [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Domestic [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	1,767,900,000	1,395,300,000
Domestic [Member] | Indiana Michigan Power Co [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Domestic [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	1,767,900,000	1,395,300,000
Domestic [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	0
Domestic [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	$ 0	$ 0

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Federal:
Current									$ (7.4)	$ (31.7)	$ (4)
Deferred									(77.1)	112.8	856.6
Deferred Investment Tax Credits									5.5	9.2	48.6
Total Federal									(79)	90.3	901.2
Current									4.4	30.8	16
Deferred									59.3	(8.5)	44.9
Deferred State and Local Investment Tax Credits									2.4	2.7	7.6
Total State and Local									66.1	25	68.5
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)									(12.9)	115.3	969.7
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income	$ 152.7	$ 733.9	$ 459.1	$ 574.1	$ 364.8	$ 579.7	$ 530.1	$ 456.7	1,919.8	1,931.3	1,928.9
Less: Equity Earnings – Dolet Hills									(72.1)	(73.1)	(82.4)
Income Tax Expense (Benefit)									(12.9)	115.3	969.7
Pretax Income									1,903.9	2,043.9	2,898.6
Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively)									$ 399.8	$ 429.2	$ 1,014.5
Federal Statutory Income Tax Rate									21.00%	21.00%	35.00%
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation									$ 23.1	$ 24.4	$ 60.2
Investment Tax Credit Amortization									(13)	(20.2)	(18.8)
Increase Decrease in income taxes due to energy production credits									(59)	(10.3)	0
State and Local Income Taxes, Net									52.2	19.7	54.7
Removal Costs									(20.7)	(19.8)	(32.7)
AFUDC									(37.1)	(29.4)	(37.4)
Valuation Allowance									0	0	(1.8)
Tax Reform Adjustments									0	(10.9)	(26.7)
Tax Adjustments									0	0	(35.8)
Tax Reform Excess ADIT Reversal									(353.2)	(257.2)	0
Other									(5)	(10.2)	(6.5)
Income Tax Expense (Benefit)									$ (12.9)	$ 115.3	$ 969.7
Effective Income Tax Rate									(0.70%)	5.60%	33.50%
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets	3,246.1				2,750.8				$ 3,246.1	$ 2,750.8
Deferred Tax Liabilities	(10,834.3)				(9,837.3)				(10,834.3)	(9,837.3)
Property Related Temporary Differences	(6,602.9)				(6,224.8)				(6,602.9)	(6,224.8)
Amounts Due from Customers for Future Federal Income Taxes	1,173.5				1,329.7				1,173.5	1,329.7
Deferred State Income Taxes	(1,112.4)				(1,072.5)				(1,112.4)	(1,072.5)
Securitized Assets	(178.7)				(186.6)				(178.7)	(186.6)
Regulatory Assets	(371.1)				(454.1)				(371.1)	(454.1)
Accrued Nuclear Decommissioning	(557.4)				(453.7)				(557.4)	(453.7)
Net Operating Loss Carryforward	77.6				78.3				77.6	78.3
Tax Credit Carryforward	247.2				113.7				247.2	113.7
Investment in Partnership	(446.6)				(300.5)				(446.6)	(300.5)
All Other, Net	0				84				0	84
Net Deferred Tax Liabilities	(7,588.2)				(7,086.5)				(7,588.2)	(7,086.5)
Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits
Balance at January 1,				14.6				86.6	14.6	86.6	$ 98.8
Increase - Tax Positions Taken During a Prior Period									8.8	0.1	4.5
Decrease - Tax Positions Taken During a Prior Period									(2.1)	0	(28)
Increase - Tax Positions Taken During the Current Year									2.8	0	3.4
Decrease - Tax Positions Taken During the Current Year									0	0	0
Decrease - Settlements with Taxing Authorities									0	(71)	7.9
Decrease - Lapse of the Applicable Statute of Limitations									0	(1.1)	0
Balance at December 31,	24.1				14.6				24.1	14.6	86.6
Tax Contingency [Abstract]
Unrecognized Tax Benefits, if Recognized - Amount	20.3				11.6				$ 20.3	11.6	10.5
Income Taxes (Textuals) [Abstract]
Period with No Change in Unrecognized Tax Benefits									12 months
Income Tax Expense (Benefit)									$ (12.9)	115.3	969.7
Kentucky Single Corporate Tax Rate									5.00%
Kentucky Net Operating Loss Limitation Percent									80.00%
Remeasurement of Kentucky Deferred Taxes [Member]
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)									$ (18)
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Income Tax Expense (Benefit)									(18)
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Income Tax Expense (Benefit)									(18)
Income Taxes (Textuals) [Abstract]
Income Tax Expense (Benefit)									$ (18)
Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date									Dec. 31, 2031
Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date									Dec. 31, 2039
AEP Texas Inc. [Member]
Federal:
Current									$ (31.8)	37	(85.7)
Deferred									(23.5)	(16.4)	63.3
Deferred Investment Tax Credits									(1.2)	(1.5)	(1.6)
Total Federal									(56.5)	19.1	(24)
Current									2.9	1.8	0.6
Deferred									0	(0.1)	0
Deferred State and Local Investment Tax Credits									0	0	0
Total State and Local									2.9	1.7	0.6
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)									(53.6)	20.8	(23.4)
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income	(13.7)	77	80.6	34.4	60.2	57.8	46.5	46.8	178.3	211.3	310.5
Income Tax Expense (Benefit)									(53.6)	20.8	(23.4)
Pretax Income									124.7	232.1	287.1
Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively)									$ 26.2	$ 48.7	$ 100.5
Federal Statutory Income Tax Rate									21.00%	21.00%	35.00%
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation									$ 1	$ 1.4	$ (0.5)
Investment Tax Credit Amortization									(1.2)	(2.3)	(1.5)
State and Local Income Taxes, Net									2.3	1.3	0.4
AFUDC									(3.2)	(4.2)	(3.9)
Parent Company Loss Benefit									(4.6)	(3.1)	0
Tax Reform Adjustments									0	(11)	(117.4)
Tax Adjustments									0	0	(4.2)
Tax Reform Excess ADIT Reversal									(73.4)	(11.8)	0
Other									(0.7)	1.8	3.2
Income Tax Expense (Benefit)									$ (53.6)	$ 20.8	$ (23.4)
Effective Income Tax Rate									(43.00%)	9.00%	(8.20%)
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets	220				208.1				$ 220	$ 208.1
Deferred Tax Liabilities	(1,185.4)				(1,121.2)				(1,185.4)	(1,121.2)
Property Related Temporary Differences	(973.5)				(836.3)				(973.5)	(836.3)
Amounts Due from Customers for Future Federal Income Taxes	126.7				141.2				126.7	141.2
Deferred State Income Taxes	(27.5)				(27.7)				(27.5)	(27.7)
Securitized Assets	(124.3)				(134.7)				(124.3)	(134.7)
Regulatory Assets	(51.2)				(53.9)				(51.2)	(53.9)
Deferred Revenues	19.9				4.6				19.9	4.6
All Other, Net	47.3				(6.3)				47.3	(6.3)
Net Deferred Tax Liabilities	(965.4)				(913.1)				(965.4)	(913.1)
Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits
Balance at January 1,				(0.8)				(0.8)	(0.8)	(0.8)	$ 6.5
Increase - Tax Positions Taken During a Prior Period									1.5	0	2
Decrease - Tax Positions Taken During a Prior Period									(0.7)	0	(12.3)
Increase - Tax Positions Taken During the Current Year									0	0	0
Decrease - Tax Positions Taken During the Current Year									0	0	0
Decrease - Settlements with Taxing Authorities									0	0	3
Decrease - Lapse of the Applicable Statute of Limitations									0	0	0
Balance at December 31,	0				(0.8)				0	(0.8)	(0.8)
Tax Contingency [Abstract]
Unrecognized Tax Benefits, if Recognized - Amount	0				(0.7)				$ 0	(0.7)	(0.5)
Income Taxes (Textuals) [Abstract]
Period with No Change in Unrecognized Tax Benefits									12 months
Income Tax Expense (Benefit)									$ (53.6)	20.8	(23.4)
AEP Texas Inc. [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date									Dec. 31, 2031
AEP Texas Inc. [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date									Dec. 31, 2039
AEP Transmission Co [Member]
Federal:
Current									$ 23.7	(14.2)	(130.4)
Deferred									71.7	82.3	254.8
Deferred Investment Tax Credits									0	0	0
Total Federal									95.4	68.1	124.4
Current									2.4	(0.6)	1.1
Deferred									19.6	16.6	16.7
Deferred State and Local Investment Tax Credits									0	0	0
Total State and Local									22	16	17.8
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)									117.4	84.1	142.2
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income	91.8	107.6	136	104.3	71.7	78.1	82	84.1	439.7	315.9	270.7
Income Tax Expense (Benefit)									117.4	84.1	142.2
Pretax Income									557.1	400	412.9
Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively)									$ 117	$ 84	$ 144.5
Federal Statutory Income Tax Rate									21.00%	21.00%	35.00%
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
State and Local Income Taxes, Net									$ 17.4	$ 12.6	$ 13.1
AFUDC									(17.7)	(14.1)	(17)
Tax Reform Adjustments									0	0	0.6
Other									0.7	1.6	1
Income Tax Expense (Benefit)									$ 117.4	$ 84.1	$ 142.2
Effective Income Tax Rate									21.10%	21.00%	34.40%
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets	162.9				142.9				$ 162.9	$ 142.9
Deferred Tax Liabilities	(980.7)				(847.3)				(980.7)	(847.3)
Property Related Temporary Differences	(847.1)				(755)				(847.1)	(755)
Amounts Due from Customers for Future Federal Income Taxes	119.9				121.3				119.9	121.3
Deferred State Income Taxes	(86.1)				(71.6)				(86.1)	(71.6)
Net Operating Loss Carryforward	12.3				13.4				12.3	13.4
All Other, Net	(16.8)				(12.5)				(16.8)	(12.5)
Net Deferred Tax Liabilities	(817.8)				(704.4)				(817.8)	(704.4)
Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits
Balance at January 1,				0				0	0	0	$ 0
Increase - Tax Positions Taken During a Prior Period									0	0	0
Decrease - Tax Positions Taken During a Prior Period									0	0	0
Increase - Tax Positions Taken During the Current Year									0	0	0
Decrease - Tax Positions Taken During the Current Year									0	0	0
Decrease - Settlements with Taxing Authorities									0	0	0
Decrease - Lapse of the Applicable Statute of Limitations									0	0	0
Balance at December 31,	0				0				0	0	0
Tax Contingency [Abstract]
Unrecognized Tax Benefits, if Recognized - Amount	0				0				$ 0	0	0
Income Taxes (Textuals) [Abstract]
Period with No Change in Unrecognized Tax Benefits									12 months
Income Tax Expense (Benefit)									$ 117.4	84.1	142.2
Kentucky Single Corporate Tax Rate									5.00%
Kentucky Net Operating Loss Limitation Percent									80.00%
AEP Transmission Co [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date									Dec. 31, 2031
AEP Transmission Co [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date									Dec. 31, 2039
Appalachian Power Co [Member]
Federal:
Current									$ 36.7	(31.9)	15.3
Deferred									(125.6)	(24.6)	166.9
Deferred Investment Tax Credits									(0.5)	0.1	(0.1)
Total Federal									(89.4)	(56.4)	182.1
Current									12	3.7	(1.4)
Deferred									(0.6)	7.8	4.6
Deferred State and Local Investment Tax Credits									0	0	0
Total State and Local									11.4	11.5	3.2
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)									(78)	(44.9)	185.3
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income	12.8	104.3	55.5	133.7	77.8	87.1	77.4	125.5	306.3	367.8	331.3
Income Tax Expense (Benefit)									(78)	(44.9)	185.3
Pretax Income									228.3	322.9	516.6
Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively)									$ 47.9	$ 67.8	$ 180.8
Federal Statutory Income Tax Rate									21.00%	21.00%	35.00%
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation									$ 11.7	$ 8.5	$ 18
State and Local Income Taxes, Net									9	9.1	3.5
Removal Costs									(6.1)	(9.6)	(12.4)
AFUDC									(5.2)	(4.3)	(5)
Valuation Allowance									(3.8)	(3.4)	(0.2)
Tax Reform Adjustments									0	0.1	4.3
Tax Reform Excess ADIT Reversal									(130.4)	(108.5)	0
Other									(1.1)	(4.6)	(3.7)
Income Tax Expense (Benefit)									$ (78)	$ (44.9)	$ 185.3
Effective Income Tax Rate									(34.20%)	(13.90%)	35.90%
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets	486.2				475.2				$ 486.2	$ 475.2
Deferred Tax Liabilities	(2,167)				(2,101)				(2,167)	(2,101)
Property Related Temporary Differences	(1,420)				(1,393.6)				(1,420)	(1,393.6)
Amounts Due from Customers for Future Federal Income Taxes	222.8				268				222.8	268
Deferred State Income Taxes	(320.9)				(324.1)				(320.9)	(324.1)
Securitized Assets	(49.3)				(54.3)				(49.3)	(54.3)
Regulatory Assets	(71)				(73.8)				(71)	(73.8)
All Other, Net	(58.9)				(48)				(58.9)	(48)
Net Deferred Tax Liabilities	(1,680.8)				(1,625.8)				(1,680.8)	(1,625.8)
Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits
Balance at January 1,				0				0	0	0	$ 0
Increase - Tax Positions Taken During a Prior Period									0	0	0
Decrease - Tax Positions Taken During a Prior Period									0	0	0
Increase - Tax Positions Taken During the Current Year									0	0	0
Decrease - Tax Positions Taken During the Current Year									0	0	0
Decrease - Settlements with Taxing Authorities									0	0	0
Decrease - Lapse of the Applicable Statute of Limitations									0	0	0
Balance at December 31,	0				0				0	0	0
Tax Contingency [Abstract]
Unrecognized Tax Benefits, if Recognized - Amount	0				0				$ 0	0	0
Income Taxes (Textuals) [Abstract]
Period with No Change in Unrecognized Tax Benefits									12 months
Income Tax Expense (Benefit)									$ (78)	(44.9)	185.3
Appalachian Power Co [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date									Dec. 31, 2031
Appalachian Power Co [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date									Dec. 31, 2039
Indiana Michigan Power Co [Member]
Federal:
Current									$ 48.1	60.9	(106.5)
Deferred									(53.5)	(44.1)	202.1
Deferred Investment Tax Credits									(3.6)	(4.7)	(4.7)
Total Federal									(9)	12.1	90.9
Current									(2.4)	15.8	(8.1)
Deferred									0.8	1.2	(1.4)
Deferred State and Local Investment Tax Credits									0	0	0
Total State and Local									(1.6)	17	(9.5)
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)									(10.6)	29.1	81.4
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income	21.4	88.8	60.3	98.9	29.7	72.7	94.7	64.2	269.4	261.3	186.7
Income Tax Expense (Benefit)									(10.6)	29.1	81.4
Pretax Income									258.8	290.4	268.1
Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively)									$ 54.3	$ 61	$ 93.8
Federal Statutory Income Tax Rate									21.00%	21.00%	35.00%
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation									$ 6.3	$ (0.7)	$ 11.4
Investment Tax Credit Amortization									(3.6)	(4.7)	(4.7)
State and Local Income Taxes, Net									(1.2)	13.4	(1)
Removal Costs									(11.5)	(8)	(13.3)
AFUDC									(4.1)	(2.5)	(5.6)
Parent Company Loss Benefit									(4.8)	(2.3)	0
Tax Reform Adjustments									0	0	(2.9)
Tax Adjustments									0	0	2.7
Tax Reform Excess ADIT Reversal									(42.5)	(25.8)	0
Other									(3.5)	(1.3)	1
Income Tax Expense (Benefit)									$ (10.6)	$ 29.1	$ 81.4
Effective Income Tax Rate									(4.10%)	10.00%	30.40%
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets	970.5				771.6				$ 970.5	$ 771.6
Deferred Tax Liabilities	(1,950.2)				(1,719.6)				(1,950.2)	(1,719.6)
Property Related Temporary Differences	(430.7)				(445)				(430.7)	(445)
Amounts Due from Customers for Future Federal Income Taxes	169.6				186.2				169.6	186.2
Deferred State Income Taxes	(194.4)				(183.9)				(194.4)	(183.9)
Regulatory Assets	(26.9)				(31.9)				(26.9)	(31.9)
Accrued Nuclear Decommissioning	(557.4)				(453.7)				(557.4)	(453.7)
Net Operating Loss Carryforward	0				0.2				0	0.2
All Other, Net	(1.8)				(19.9)				(1.8)	(19.9)
Net Deferred Tax Liabilities	(979.7)				(948)				(979.7)	(948)
Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits
Balance at January 1,				3.2				3.2	3.2	3.2	$ 3.8
Increase - Tax Positions Taken During a Prior Period									0	0	0.2
Decrease - Tax Positions Taken During a Prior Period									(0.7)	0	(0.5)
Increase - Tax Positions Taken During the Current Year									0	0	0
Decrease - Tax Positions Taken During the Current Year									0	0	0
Decrease - Settlements with Taxing Authorities									0	0	(0.3)
Decrease - Lapse of the Applicable Statute of Limitations									0	0	0
Balance at December 31,	2.5				3.2				2.5	3.2	3.2
Tax Contingency [Abstract]
Unrecognized Tax Benefits, if Recognized - Amount	2				2.6				$ 2	2.6	2.1
Income Taxes (Textuals) [Abstract]
Period with No Change in Unrecognized Tax Benefits									12 months
Income Tax Expense (Benefit)									$ (10.6)	29.1	81.4
Kentucky Single Corporate Tax Rate									5.00%
Kentucky Net Operating Loss Limitation Percent									80.00%
Indiana Michigan Power Co [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date									Dec. 31, 2031
Indiana Michigan Power Co [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date									Dec. 31, 2039
Ohio Power Co [Member]
Federal:
Current									$ (10)	55.6	11.2
Deferred									40.6	(36.9)	141.3
Deferred Investment Tax Credits									0	0	0
Total Federal									30.6	18.7	152.5
Current									1.1	4.6	0.2
Deferred									3.2	0.7	6.6
Deferred State and Local Investment Tax Credits									0	0	0
Total State and Local									4.3	5.3	6.8
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)									34.9	24	159.3
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income	49.4	69.1	50.6	128	88.4	88.7	68.8	79.6	297.1	325.5	323.9
Income Tax Expense (Benefit)									34.9	24	159.3
Pretax Income									332	349.5	483.2
Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively)									$ 69.7	$ 73.4	$ 169.1
Federal Statutory Income Tax Rate									21.00%	21.00%	35.00%
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation									$ (1.7)	$ 2.6	$ 7.6
State and Local Income Taxes, Net									3.4	4.2	4.4
AFUDC									(3.8)	(2.1)	(2.2)
Parent Company Loss Benefit									(4.9)	(5.5)	(0.2)
Tax Reform Adjustments									0	0	(14.4)
Tax Reform Excess ADIT Reversal									(27.3)	(51)	0
Other									(0.5)	2.4	(5)
Income Tax Expense (Benefit)									$ 34.9	$ 24	$ 159.3
Effective Income Tax Rate									10.50%	6.90%	33.00%
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets	202.3				209				$ 202.3	$ 209
Deferred Tax Liabilities	(1,051.6)				(972.3)				(1,051.6)	(972.3)
Property Related Temporary Differences	(890.8)				(826.9)				(890.8)	(826.9)
Amounts Due from Customers for Future Federal Income Taxes	130.2				137				130.2	137
Deferred State Income Taxes	(35.5)				(32.9)				(35.5)	(32.9)
Regulatory Assets	(48)				(55)				(48)	(55)
All Other, Net	(23.5)				14.5				(23.5)	14.5
Net Deferred Tax Liabilities	(849.3)				(763.3)				(849.3)	(763.3)
Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits
Balance at January 1,				6.9				6.9	6.9	6.9	$ 6.9
Increase - Tax Positions Taken During a Prior Period									1.6	0	0
Decrease - Tax Positions Taken During a Prior Period									0	0	0
Increase - Tax Positions Taken During the Current Year									0	0	0
Decrease - Tax Positions Taken During the Current Year									0	0	0
Decrease - Settlements with Taxing Authorities									0	0	0
Decrease - Lapse of the Applicable Statute of Limitations									0	0	0
Balance at December 31,	8.5				6.9				8.5	6.9	6.9
Tax Contingency [Abstract]
Unrecognized Tax Benefits, if Recognized - Amount	6.7				5.4				$ 6.7	5.4	4.5
Income Taxes (Textuals) [Abstract]
Period with No Change in Unrecognized Tax Benefits									12 months
Income Tax Expense (Benefit)									$ 34.9	24	159.3
Kentucky Single Corporate Tax Rate									5.00%
Kentucky Net Operating Loss Limitation Percent									80.00%
Ohio Power Co [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date									Dec. 31, 2031
Ohio Power Co [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date									Dec. 31, 2039
Public Service Co Of Oklahoma [Member]
Federal:
Current									$ 25.5	35.6	(77.1)
Deferred									(23.6)	(34.7)	122.7
Deferred Investment Tax Credits									(2.4)	(2)	(1.6)
Total Federal									(0.5)	(1.1)	44
Current									0.2	(0.2)	(0.2)
Deferred									5.4	3.6	2
Deferred State and Local Investment Tax Credits									2.4	2.7	4.3
Total State and Local									8	6.1	6.1
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)									7.5	5	50.1
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income	(10.8)	100.3	41.9	6.2	(6.6)	60.4	36.6	(7.2)	137.6	83.2	72
Income Tax Expense (Benefit)									7.5	5	50.1
Pretax Income									145.1	88.2	122.1
Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively)									$ 30.5	$ 18.5	$ 42.7
Federal Statutory Income Tax Rate									21.00%	21.00%	35.00%
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation									$ 0.5	$ 1	$ 0.3
Investment Tax Credit Amortization									(0.5)	(1.7)	(1.6)
State and Local Income Taxes, Net									6.3	4.8	4
Parent Company Loss Benefit									(2.5)	(1.4)	0
Tax Reform Adjustments									0	0	2.8
Tax Reform Excess ADIT Reversal									(24.5)	(15.5)	0
Other									(2.3)	(0.7)	1.9
Income Tax Expense (Benefit)									$ 7.5	$ 5	$ 50.1
Effective Income Tax Rate									5.20%	5.70%	41.00%
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets	257.4				229.6				$ 257.4	$ 229.6
Deferred Tax Liabilities	(885.7)				(837.4)				(885.7)	(837.4)
Property Related Temporary Differences	(627.6)				(609.4)				(627.6)	(609.4)
Amounts Due from Customers for Future Federal Income Taxes	127.2				138.9				127.2	138.9
Deferred State Income Taxes	(100.4)				(135.6)				(100.4)	(135.6)
Regulatory Assets	(44.6)				(32.3)				(44.6)	(32.3)
Net Operating Loss Carryforward	10.2				16.4				10.2	16.4
All Other, Net	6.9				14.2				6.9	14.2
Net Deferred Tax Liabilities	(628.3)				(607.8)				(628.3)	(607.8)
Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits
Balance at January 1,				0				0	0	0	$ 0.1
Increase - Tax Positions Taken During a Prior Period									0	0	0.1
Decrease - Tax Positions Taken During a Prior Period									0	0	(0.9)
Increase - Tax Positions Taken During the Current Year									0	0	0
Decrease - Tax Positions Taken During the Current Year									0	0	0
Decrease - Settlements with Taxing Authorities									0	0	0.7
Decrease - Lapse of the Applicable Statute of Limitations									0	0	0
Balance at December 31,	0				0				0	0	0
Tax Contingency [Abstract]
Unrecognized Tax Benefits, if Recognized - Amount	0				0				$ 0	0	0
Income Taxes (Textuals) [Abstract]
Period with No Change in Unrecognized Tax Benefits									12 months
Income Tax Expense (Benefit)									$ 7.5	5	50.1
Public Service Co Of Oklahoma [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date									Dec. 31, 2031
Public Service Co Of Oklahoma [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date									Dec. 31, 2039
Southwestern Electric Power Co [Member]
Federal:
Current									$ 6.9	18.3	(30.1)
Deferred									(8.6)	(0.5)	84.8
Deferred Investment Tax Credits									(1.4)	(1.4)	(1.4)
Total Federal									(3.1)	16.4	53.3
Current									0.8	2.3	(0.9)
Deferred									(2.4)	1.7	(4.3)
Deferred State and Local Investment Tax Credits									0	0	0
Total State and Local									(1.6)	4	(5.2)
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)									(4.7)	20.4	48.1
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income	14.6	$ 111.3	$ 7.3	29	10.5	$ 89.6	$ 38.7	13.4	162.2	152.2	137.5
Less: Equity Earnings – Dolet Hills									(3)	(2.7)	3.8
Income Tax Expense (Benefit)									(4.7)	20.4	48.1
Pretax Income									154.5	169.9	185.6
Income Taxes on Pretax Income at Statutory Rate (21%, 21% and 35% in 2019, 2018 and 2017, Respectively)									$ 32.4	$ 35.7	$ 65
Federal Statutory Income Tax Rate									21.00%	21.00%	35.00%
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation									$ 1.9	$ 3.4	$ 1.9
Depletion									(3.6)	(3.2)	(5.7)
State and Local Income Taxes, Net									(1.3)	3.2	(2.3)
AFUDC									(1.4)	(1.3)	(0.9)
Tax Reform Adjustments									0	0	(0.4)
Tax Adjustments									0	0	(9.9)
Tax Reform Excess ADIT Reversal									(29.9)	(16)	0
Other									(2.8)	(1.4)	0.4
Income Tax Expense (Benefit)									$ (4.7)	$ 20.4	$ 48.1
Effective Income Tax Rate									(3.00%)	12.00%	25.90%
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets	359.6				317.4				$ 359.6	$ 317.4
Deferred Tax Liabilities	(1,300.5)				(1,220.2)				(1,300.5)	(1,220.2)
Property Related Temporary Differences	(947.6)				(913.3)				(947.6)	(913.3)
Amounts Due from Customers for Future Federal Income Taxes	169.8				183.4				169.8	183.4
Deferred State Income Taxes	(200.3)				(193.6)				(200.3)	(193.6)
Regulatory Assets	(30.2)				(30.8)				(30.2)	(30.8)
Net Operating Loss Carryforward	38.2				36.2				38.2	36.2
All Other, Net	29.2				15.3				29.2	15.3
Net Deferred Tax Liabilities	(940.9)				(902.8)				(940.9)	(902.8)
Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits
Balance at January 1,				$ (0.8)				$ (0.8)	(0.8)	(0.8)	$ 1.3
Increase - Tax Positions Taken During a Prior Period									0.8	0	1.7
Decrease - Tax Positions Taken During a Prior Period									0	0	(5.4)
Increase - Tax Positions Taken During the Current Year									0	0	0
Decrease - Tax Positions Taken During the Current Year									0	0	0
Decrease - Settlements with Taxing Authorities									0	0	1.6
Decrease - Lapse of the Applicable Statute of Limitations									0	0	0
Balance at December 31,	0				(0.8)				0	(0.8)	(0.8)
Tax Contingency [Abstract]
Unrecognized Tax Benefits, if Recognized - Amount	0				$ (0.6)				$ 0	(0.6)	(0.5)
Income Taxes (Textuals) [Abstract]
Period with No Change in Unrecognized Tax Benefits									12 months
Income Tax Expense (Benefit)									$ (4.7)	20.4	48.1
Southwestern Electric Power Co [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date									Dec. 31, 2031
Southwestern Electric Power Co [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date									Dec. 31, 2039
Arkansas [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	102.5								$ 102.5
Arkansas [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2020
Arkansas [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2024
Arkansas [Member] | Southwestern Electric Power Co [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	101.7								$ 101.7
Arkansas [Member] | Southwestern Electric Power Co [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2021
Arkansas [Member] | Southwestern Electric Power Co [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2024
Kentucky [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	144.9								$ 144.9
Kentucky [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2030
Kentucky [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2037
Louisiana [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	541								$ 541
Louisiana [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2025
Louisiana [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2039
Louisiana [Member] | Southwestern Electric Power Co [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	528.1								$ 528.1
Louisiana [Member] | Southwestern Electric Power Co [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2032
Louisiana [Member] | Southwestern Electric Power Co [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2037
Oklahoma [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	544.1								$ 544.1
Oklahoma [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2034
Oklahoma [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2037
Oklahoma [Member] | AEP Transmission Co [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	269.4								$ 269.4
Oklahoma [Member] | AEP Transmission Co [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2034
Oklahoma [Member] | AEP Transmission Co [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2037
Oklahoma [Member] | Public Service Co Of Oklahoma [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	240.5								$ 240.5
Oklahoma [Member] | Public Service Co Of Oklahoma [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2034
Oklahoma [Member] | Public Service Co Of Oklahoma [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2037
Tennessee [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	29								$ 29
Tennessee [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2028
Tennessee [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2034
Virginia [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	22.6								$ 22.6
Virginia [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2030
Virginia [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2037
West Virginia [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	16.1								$ 16.1
West Virginia [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2029
West Virginia [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2037
West Virginia [Member] | Indiana Michigan Power Co [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	2								$ 2
West Virginia [Member] | Indiana Michigan Power Co [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2031
West Virginia [Member] | Indiana Michigan Power Co [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2037
Ohio Municipal [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	414.1								$ 414.1
Ohio Municipal [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2020
Ohio Municipal [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2024
Ohio Municipal [Member] | AEP Transmission Co [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	37.3								$ 37.3
Ohio Municipal [Member] | AEP Transmission Co [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2020
Ohio Municipal [Member] | AEP Transmission Co [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date									Dec. 31, 2023
Federal [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	247.2								$ 247.2
Tax Credit Carryforward Amount To Expire If Not Used	239.6								239.6
Federal [Member] | AEP Texas Inc. [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	1.4								1.4
Tax Credit Carryforward Amount To Expire If Not Used	1.3								1.3
Federal [Member] | AEP Transmission Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	0.2								0.2
Tax Credit Carryforward Amount To Expire If Not Used	0.1								0.1
Federal [Member] | Appalachian Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	4.9								4.9
Tax Credit Carryforward Amount To Expire If Not Used	2.3								2.3
Federal [Member] | Indiana Michigan Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	13.9								13.9
Tax Credit Carryforward Amount To Expire If Not Used	13.7								13.7
Federal [Member] | Ohio Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	5.1								5.1
Tax Credit Carryforward Amount To Expire If Not Used	1.7								1.7
Federal [Member] | Public Service Co Of Oklahoma [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	1.1								1.1
Tax Credit Carryforward Amount To Expire If Not Used	1.1								1.1
Federal [Member] | Southwestern Electric Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	1.9								1.9
Tax Credit Carryforward Amount To Expire If Not Used	1.8								1.8
State and Local Jurisdiction [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	36.7								36.7
Tax Credit Carryforward Amount To Expire If Not Used	0								0
Income Taxes (Textuals) [Abstract]
Valuation Allowance	6								6
State and Local Jurisdiction [Member] | AEP Texas Inc. [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	0								0
Tax Credit Carryforward Amount To Expire If Not Used	0								0
State and Local Jurisdiction [Member] | AEP Transmission Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	0								0
Tax Credit Carryforward Amount To Expire If Not Used	0								0
State and Local Jurisdiction [Member] | Appalachian Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	0								0
Tax Credit Carryforward Amount To Expire If Not Used	0								0
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	0								0
Tax Credit Carryforward Amount To Expire If Not Used	0								0
State and Local Jurisdiction [Member] | Ohio Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	0								0
Tax Credit Carryforward Amount To Expire If Not Used	0								0
State and Local Jurisdiction [Member] | Public Service Co Of Oklahoma [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	36.7								36.7
Tax Credit Carryforward Amount To Expire If Not Used	0								0
State and Local Jurisdiction [Member] | Southwestern Electric Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	0								0
Tax Credit Carryforward Amount To Expire If Not Used	$ 0								0
Dolet Hills Lignite Co, LLC [Member]
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Less: Equity Earnings – Dolet Hills									(3)	(2.7)	0
Dolet Hills Lignite Co, LLC [Member] | Southwestern Electric Power Co [Member]
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Less: Equity Earnings – Dolet Hills									$ (3)	$ (2.7)	$ 0

Leases (Details)

Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Lease Rental Costs
Operating Lease, Cost	$ 286	$ 245	$ 231.3
Finance Lease Right-of-Use Asset Amortization	70.8	62.4	66.3
Interest Expense on Finance Leases	16.4	16.4	16.7
Total Lease Rental Costs	$ 373.2	323.8	314.3
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases	5 years 2 months 23 days
Weighted Average Remaining Lease Term, Finance Leases	5 years 10 months 6 days
Weighted Average Discount Rate, Operating Leases	3.60%
Weighted Average Discount Rate, Finance Leases	5.98%
Operating Cash Flows Used for Operating Leases	$ 284.7
Operating Cash Flows Used for Finance Leases	16.4
Financing Cash Flows Used for Finance Leases	70.7	65.1	67.3
Non-cash Acquisitions Under Operating Leases	125
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	22,762.4	21,699.9
Other Property, Plant and Equipment	4,811.5	4,265
Total Property, Plant and Equipment	79,145.7	73,085.2
Accumulated Amortization	19,007.6	17,986.1
Net Property, Plant and Equipment Under Finance Leases	303.1	278.8
Other Liabilities, Noncurrent	719.8	782.6
Finance Lease Liability Due Within One Year	1,373.8	1,190.5
Total Obligations Under Finance Leases	306.8	289
Operating Lease Asset and Related Obligations
Operating Lease Assets	957.4	0
Operating Lease Noncurrent Liability	734.6	0
Operating Lease Liability Due Within One Year	234.1	0
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	968.7
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Finance Leases, 2020	72.7
Finance Leases, 2021	64.9
Finance Leases, 2022	56.4
Finance Leases, 2023	49.6
Finance Leases, 2024	57.4
Finance Leases, Later Years	64.4
Finance Leases, Total Future Minimum Lease Payments	365.4
Imputed Interest on Finance Leases	58.6
Total Obligations Under Finance Leases	306.8	289
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Operating Leases, 2020	269.9
Operating Leases, 2021	253.6
Operating Leases, 2022	245.6
Operating Leases, 2023	74.8
Operating Leases, 2024	62
Operating Leases, Later Years	169.7
Operating Leases, Total Future Minimum Lease Payments	1,075.6
Imputed Interest on Operating Leases	106.9
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	968.7
Finance Lease Future Minimum Lease Payments
Finance Leases, 2019		70.8
Finance Leases, 2020		60.2
Finance Leases, 2021		51.7
Finance Leases, 2022		43.8
Finance Leases, 2023		35.5
Finance Leases, Later Years		90.2
Finance Leases, Total Future Minimum Payments Due		352.2
Estimated Interest Element on Finance Leases		63.2
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		289
Operating Lease Future Minimum Lease Payments
Operating Leases, 2019		259.6
Operating Leases, 2020		250.1
Operating Leases, 2021		232.7
Operating Leases, 2022		222.5
Operating Leases, 2023		58.3
Operating Leases, Later Years		165.2
Operating Leases Total Future Minimum Lease Payments		1,188.4
Maximum Potential Loss
Max Potential Loss on Master Lease Agreements	47.3
Rockport Lease [Member]
Future Minimum Rentals, Sale Leaseback Transactions
2020	147.8
2021	147.8
2022	147.5
Total Future Minimum Lease Payments	443.1
Leases (Textuals)
Sale and Leaseback Transaction, Gain (Loss), Net	$ 37
Lease Term	33 years
Boat and Barge Leases [Member]
Leases (Textuals)
Maximum Potential Lease Payments, AEPRO Barge and Boat Leases	$ 55
Guarantor Obligations, Current Carrying Value	5
Guarantee Obligations Current Carrying Value Other Liabilities Current	2
Guarantee Obligations Current Carrying Value Other Liabilities Noncurrent	3
Finance Lease Assets [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	131.6	131.3
Other Property, Plant and Equipment	323	373.9
Total Property, Plant and Equipment	454.6	505.2
Accumulated Amortization	151.5	226.4
Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Other Liabilities, Noncurrent	249.2	233.5
Finance Lease Liability Due Within One Year	57.6	55.5
Operating Lease Assets [Member]
Operating Lease Asset and Related Obligations
Operating Lease Assets	957.4
AEP Texas Inc. [Member]
Lease Rental Costs
Operating Lease, Cost	16.5	13.6	10.5
Finance Lease Right-of-Use Asset Amortization	5.1	4.8	4
Interest Expense on Finance Leases	1.4	1.2	0.8
Total Lease Rental Costs	$ 23	19.6	15.3
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases	6 years 11 months 4 days
Weighted Average Remaining Lease Term, Finance Leases	6 years 8 months 8 days
Weighted Average Discount Rate, Operating Leases	3.77%
Weighted Average Discount Rate, Finance Leases	4.62%
Operating Cash Flows Used for Operating Leases	$ 15.3
Operating Cash Flows Used for Finance Leases	1.4
Financing Cash Flows Used for Finance Leases	5.1	4.7	3.9
Non-cash Acquisitions Under Operating Leases	13.8
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	351.7	352.1
Other Property, Plant and Equipment	805.9	727.9
Total Property, Plant and Equipment	10,603.2	9,643
Accumulated Amortization	1,758.1	1,651.2
Net Property, Plant and Equipment Under Finance Leases	34.1	28.5
Other Liabilities, Noncurrent	81.1	104
Finance Lease Liability Due Within One Year	188	98.3
Total Obligations Under Finance Leases	34.1	28.5
Operating Lease Asset and Related Obligations
Operating Lease Noncurrent Liability	71.1	0
Operating Lease Liability Due Within One Year	12	0
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	83.1
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Finance Leases, 2020	7.3
Finance Leases, 2021	6.7
Finance Leases, 2022	6
Finance Leases, 2023	5.4
Finance Leases, 2024	4.6
Finance Leases, Later Years	9.8
Finance Leases, Total Future Minimum Lease Payments	39.8
Imputed Interest on Finance Leases	5.7
Total Obligations Under Finance Leases	34.1	28.5
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Operating Leases, 2020	16
Operating Leases, 2021	15.3
Operating Leases, 2022	14.2
Operating Leases, 2023	13
Operating Leases, 2024	11.4
Operating Leases, Later Years	26
Operating Leases, Total Future Minimum Lease Payments	95.9
Imputed Interest on Operating Leases	12.8
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	83.1
Finance Lease Future Minimum Lease Payments
Finance Leases, 2019		5.8
Finance Leases, 2020		5.3
Finance Leases, 2021		4.7
Finance Leases, 2022		4.2
Finance Leases, 2023		3.7
Finance Leases, Later Years		10.1
Finance Leases, Total Future Minimum Payments Due		33.8
Estimated Interest Element on Finance Leases		5.3
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		28.5
Operating Lease Future Minimum Lease Payments
Operating Leases, 2019		15.1
Operating Leases, 2020		14.1
Operating Leases, 2021		13.2
Operating Leases, 2022		12.2
Operating Leases, 2023		10.8
Operating Leases, Later Years		28.4
Operating Leases Total Future Minimum Lease Payments		93.8
Maximum Potential Loss
Max Potential Loss on Master Lease Agreements	11.3
AEP Texas Inc. [Member] | Finance Lease Assets [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	0	0
Other Property, Plant and Equipment	45.9	38.8
Total Property, Plant and Equipment	45.9	38.8
Accumulated Amortization	11.8	10.3
AEP Texas Inc. [Member] | Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Other Liabilities, Noncurrent	28.2	24
Finance Lease Liability Due Within One Year	5.9	4.5
AEP Texas Inc. [Member] | Operating Lease Assets [Member]
Operating Lease Asset and Related Obligations
Operating Lease Assets	81.8
AEP Transmission Co [Member]
Lease Rental Costs
Operating Lease, Cost	2.5	2.7	1.7
Finance Lease Right-of-Use Asset Amortization	0.1	0.1	0
Interest Expense on Finance Leases	0	0	0
Total Lease Rental Costs	$ 2.6	2.8	1.7
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases	2 years 3 months
Weighted Average Remaining Lease Term, Finance Leases	3 months
Weighted Average Discount Rate, Operating Leases	3.14%
Weighted Average Discount Rate, Finance Leases	9.33%
Operating Cash Flows Used for Operating Leases	$ 2.4
Operating Cash Flows Used for Finance Leases	0
Financing Cash Flows Used for Finance Leases	0
Non-cash Acquisitions Under Operating Leases	0.6
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Other Property, Plant and Equipment	269.6	174
Total Property, Plant and Equipment	9,893.2	8,268.1
Accumulated Amortization	402.3	271.9
Net Property, Plant and Equipment Under Finance Leases	0	0.1
Other Liabilities, Noncurrent	0.3	18.4
Finance Lease Liability Due Within One Year	14.6	3.8
Total Obligations Under Finance Leases	0	0.1
Operating Lease Asset and Related Obligations
Operating Lease Noncurrent Liability	1.9	0
Operating Lease Liability Due Within One Year	2.1	0
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	4
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Finance Leases, 2020	0
Finance Leases, 2021	0
Finance Leases, 2022	0
Finance Leases, 2023	0
Finance Leases, 2024	0
Finance Leases, Later Years	0
Finance Leases, Total Future Minimum Lease Payments	0
Imputed Interest on Finance Leases	0
Total Obligations Under Finance Leases	0	0.1
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Operating Leases, 2020	2.2
Operating Leases, 2021	1.2
Operating Leases, 2022	0.6
Operating Leases, 2023	0.1
Operating Leases, 2024	0
Operating Leases, Later Years	0
Operating Leases, Total Future Minimum Lease Payments	4.1
Imputed Interest on Operating Leases	0.1
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	4
Finance Lease Future Minimum Lease Payments
Finance Leases, 2019		0.1
Finance Leases, 2020		0
Finance Leases, 2021		0
Finance Leases, 2022		0
Finance Leases, 2023		0
Finance Leases, Later Years		0
Finance Leases, Total Future Minimum Payments Due		0.1
Estimated Interest Element on Finance Leases		0
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		0.1
Operating Lease Future Minimum Lease Payments
Operating Leases, 2019		2.3
Operating Leases, 2020		1.8
Operating Leases, 2021		1
Operating Leases, 2022		0.5
Operating Leases, 2023		0.1
Operating Leases, Later Years		0
Operating Leases Total Future Minimum Lease Payments		5.7
AEP Transmission Co [Member] | Finance Lease Assets [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	0	0
Other Property, Plant and Equipment	0.2	0.2
Total Property, Plant and Equipment	0.2	0.2
Accumulated Amortization	0.2	0.1
AEP Transmission Co [Member] | Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Other Liabilities, Noncurrent	0	0
Finance Lease Liability Due Within One Year	0	0.1
AEP Transmission Co [Member] | Operating Lease Assets [Member]
Operating Lease Asset and Related Obligations
Operating Lease Assets	3.8
Appalachian Power Co [Member]
Lease Rental Costs
Operating Lease, Cost	19.5	18.2	17.5
Finance Lease Right-of-Use Asset Amortization	6.7	7	6.9
Interest Expense on Finance Leases	2.9	3	3.7
Total Lease Rental Costs	$ 29.1	28.2	28.1
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases	6 years 3 months 10 days
Weighted Average Remaining Lease Term, Finance Leases	6 years 1 month 13 days
Weighted Average Discount Rate, Operating Leases	3.64%
Weighted Average Discount Rate, Finance Leases	8.08%
Operating Cash Flows Used for Operating Leases	$ 19
Operating Cash Flows Used for Finance Leases	2.9
Financing Cash Flows Used for Finance Leases	6.7	6.9	6.9
Non-cash Acquisitions Under Operating Leases	10.2
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	6,563.7	6,509.6
Other Property, Plant and Equipment	571.3	485.8
Total Property, Plant and Equipment	15,514.2	14,792.7
Accumulated Amortization	4,432.3	4,124.4
Net Property, Plant and Equipment Under Finance Leases	41.8	39.8
Other Liabilities, Noncurrent	55.2	58.6
Finance Lease Liability Due Within One Year	170.9	191.8
Total Obligations Under Finance Leases	41.8	39.8
Operating Lease Asset and Related Obligations
Operating Lease Assets	78.5	0
Operating Lease Noncurrent Liability	64	0
Operating Lease Liability Due Within One Year	15.2	0
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	79.2
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Finance Leases, 2020	9.6
Finance Leases, 2021	8.9
Finance Leases, 2022	8.2
Finance Leases, 2023	7.7
Finance Leases, 2024	7.1
Finance Leases, Later Years	9.8
Finance Leases, Total Future Minimum Lease Payments	51.3
Imputed Interest on Finance Leases	9.5
Total Obligations Under Finance Leases	41.8	39.8
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Operating Leases, 2020	18.3
Operating Leases, 2021	15.7
Operating Leases, 2022	14.7
Operating Leases, 2023	11.9
Operating Leases, 2024	9
Operating Leases, Later Years	20
Operating Leases, Total Future Minimum Lease Payments	89.6
Imputed Interest on Operating Leases	10.4
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	79.2
Finance Lease Future Minimum Lease Payments
Finance Leases, 2019		9
Finance Leases, 2020		8
Finance Leases, 2021		7.3
Finance Leases, 2022		6.8
Finance Leases, 2023		6.3
Finance Leases, Later Years		13.3
Finance Leases, Total Future Minimum Payments Due		50.7
Estimated Interest Element on Finance Leases		10.9
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		39.8
Operating Lease Future Minimum Lease Payments
Operating Leases, 2019		17.6
Operating Leases, 2020		16.5
Operating Leases, 2021		13.9
Operating Leases, 2022		12.8
Operating Leases, 2023		9.9
Operating Leases, Later Years		20.5
Operating Leases Total Future Minimum Lease Payments		91.2
Maximum Potential Loss
Max Potential Loss on Master Lease Agreements	6.6
Appalachian Power Co [Member] | Finance Lease Assets [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	39.9	38.7
Other Property, Plant and Equipment	18.9	17.3
Total Property, Plant and Equipment	58.8	56
Accumulated Amortization	17	16.2
Appalachian Power Co [Member] | Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Other Liabilities, Noncurrent	35	33.7
Finance Lease Liability Due Within One Year	6.8	6.1
Appalachian Power Co [Member] | Operating Lease Assets [Member]
Operating Lease Asset and Related Obligations
Operating Lease Assets	78.5
Indiana Michigan Power Co [Member]
Lease Rental Costs
Operating Lease, Cost	93.1	89.2	88.4
Finance Lease Right-of-Use Asset Amortization	5.7	6.6	11.1
Interest Expense on Finance Leases	2.9	3.3	3.2
Total Lease Rental Costs	$ 101.7	99.1	102.7
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases	3 years 10 months 28 days
Weighted Average Remaining Lease Term, Finance Leases	6 years 6 months 18 days
Weighted Average Discount Rate, Operating Leases	3.45%
Weighted Average Discount Rate, Finance Leases	8.47%
Operating Cash Flows Used for Operating Leases	$ 94.3
Operating Cash Flows Used for Finance Leases	3.1
Financing Cash Flows Used for Finance Leases	5.7	8.8	12
Non-cash Acquisitions Under Operating Leases	18.7
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	5,099.7	4,887.2
Other Property, Plant and Equipment	632.6	583.8
Total Property, Plant and Equipment	10,194	9,762.8
Accumulated Amortization	3,294.3	3,151.6
Net Property, Plant and Equipment Under Finance Leases	45.1	38.7
Other Liabilities, Noncurrent	67.8	87.8
Finance Lease Liability Due Within One Year	109.6	103
Total Obligations Under Finance Leases	45.1	38.7
Operating Lease Asset and Related Obligations
Operating Lease Assets	294.9	0
Operating Lease Noncurrent Liability	211.6	0
Operating Lease Liability Due Within One Year	87.3	0
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	298.9
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Finance Leases, 2020	9.4
Finance Leases, 2021	8.7
Finance Leases, 2022	8
Finance Leases, 2023	7.5
Finance Leases, 2024	10.8
Finance Leases, Later Years	16.4
Finance Leases, Total Future Minimum Lease Payments	60.8
Imputed Interest on Finance Leases	15.7
Total Obligations Under Finance Leases	45.1	38.7
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Operating Leases, 2020	97
Operating Leases, 2021	92.9
Operating Leases, 2022	92.8
Operating Leases, 2023	10.1
Operating Leases, 2024	8.6
Operating Leases, Later Years	21
Operating Leases, Total Future Minimum Lease Payments	322.4
Imputed Interest on Operating Leases	23.5
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	298.9
Finance Lease Future Minimum Lease Payments
Finance Leases, 2019		8.2
Finance Leases, 2020		7.2
Finance Leases, 2021		6.6
Finance Leases, 2022		6.1
Finance Leases, 2023		5.7
Finance Leases, Later Years		21.7
Finance Leases, Total Future Minimum Payments Due		55.5
Estimated Interest Element on Finance Leases		16.8
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		38.7
Operating Lease Future Minimum Lease Payments
Operating Leases, 2019		92.6
Operating Leases, 2020		89.3
Operating Leases, 2021		84.8
Operating Leases, 2022		83.8
Operating Leases, 2023		6.5
Operating Leases, Later Years		19.5
Operating Leases Total Future Minimum Lease Payments		376.5
Maximum Potential Loss
Max Potential Loss on Master Lease Agreements	4.1
Indiana Michigan Power Co [Member] | Rockport Lease [Member]
Future Minimum Rentals, Sale Leaseback Transactions
2020	73.9
2021	73.9
2022	73.7
Total Future Minimum Lease Payments	221.5
Leases (Textuals)
Sale and Leaseback Transaction, Gain (Loss), Net	$ 15
Lease Term	33 years
Indiana Michigan Power Co [Member] | Finance Lease Assets [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	$ 28.8	27
Other Property, Plant and Equipment	39.3	33.3
Total Property, Plant and Equipment	68.1	60.3
Accumulated Amortization	23	21.6
Indiana Michigan Power Co [Member] | Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Other Liabilities, Noncurrent	38.8	33.4
Finance Lease Liability Due Within One Year	6.3	5.3
Indiana Michigan Power Co [Member] | Operating Lease Assets [Member]
Operating Lease Asset and Related Obligations
Operating Lease Assets	294.9
Ohio Power Co [Member]
Lease Rental Costs
Operating Lease, Cost	18	10.7	8.2
Finance Lease Right-of-Use Asset Amortization	3.5	3.9	4.1
Interest Expense on Finance Leases	0.7	0.5	0.5
Total Lease Rental Costs	$ 22.2	15.1	12.8
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases	7 years 11 months 8 days
Weighted Average Remaining Lease Term, Finance Leases	6 years 5 months 26 days
Weighted Average Discount Rate, Operating Leases	3.76%
Weighted Average Discount Rate, Finance Leases	4.54%
Operating Cash Flows Used for Operating Leases	$ 18
Operating Cash Flows Used for Finance Leases	0.7
Financing Cash Flows Used for Finance Leases	3.5	3.8	4.1
Non-cash Acquisitions Under Operating Leases	35.4
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Other Property, Plant and Equipment	765.8	574.8
Total Property, Plant and Equipment	9,170	8,493.5
Accumulated Amortization	2,263	2,218.6
Net Property, Plant and Equipment Under Finance Leases	20.1	12.1
Other Liabilities, Noncurrent	42.7	43.8
Finance Lease Liability Due Within One Year	151.2	214.2
Total Obligations Under Finance Leases	20.1	12.1
Operating Lease Asset and Related Obligations
Operating Lease Noncurrent Liability	76	0
Operating Lease Liability Due Within One Year	12.5	0
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	88.5
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Finance Leases, 2020	4.7
Finance Leases, 2021	4.3
Finance Leases, 2022	3.4
Finance Leases, 2023	2.8
Finance Leases, 2024	2.4
Finance Leases, Later Years	5.7
Finance Leases, Total Future Minimum Lease Payments	23.3
Imputed Interest on Finance Leases	3.2
Total Obligations Under Finance Leases	20.1	12.1
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Operating Leases, 2020	16.2
Operating Leases, 2021	14.2
Operating Leases, 2022	13.5
Operating Leases, 2023	12.3
Operating Leases, 2024	10.7
Operating Leases, Later Years	36.5
Operating Leases, Total Future Minimum Lease Payments	103.4
Imputed Interest on Operating Leases	14.9
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	88.5
Finance Lease Future Minimum Lease Payments
Finance Leases, 2019		3.3
Finance Leases, 2020		2.7
Finance Leases, 2021		2.3
Finance Leases, 2022		1.7
Finance Leases, 2023		1.2
Finance Leases, Later Years		2.8
Finance Leases, Total Future Minimum Payments Due		14
Estimated Interest Element on Finance Leases		1.9
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		12.1
Operating Lease Future Minimum Lease Payments
Operating Leases, 2019		14.5
Operating Leases, 2020		13.2
Operating Leases, 2021		10.9
Operating Leases, 2022		10
Operating Leases, 2023		8.8
Operating Leases, Later Years		31.7
Operating Leases Total Future Minimum Lease Payments		89.1
Maximum Potential Loss
Max Potential Loss on Master Lease Agreements	7.3
Ohio Power Co [Member] | Finance Lease Assets [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	0	0
Other Property, Plant and Equipment	27.3	20.4
Total Property, Plant and Equipment	27.3	20.4
Accumulated Amortization	7.2	8.3
Ohio Power Co [Member] | Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Other Liabilities, Noncurrent	16.2	9.2
Finance Lease Liability Due Within One Year	3.9	2.9
Ohio Power Co [Member] | Operating Lease Assets [Member]
Operating Lease Asset and Related Obligations
Operating Lease Assets	88
Public Service Co Of Oklahoma [Member]
Lease Rental Costs
Operating Lease, Cost	6.8	5.7	4.4
Finance Lease Right-of-Use Asset Amortization	3.1	3.2	4
Interest Expense on Finance Leases	0.6	0.4	0.6
Total Lease Rental Costs	$ 10.5	9.3	9
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases	7 years 25 days
Weighted Average Remaining Lease Term, Finance Leases	6 years 2 months 23 days
Weighted Average Discount Rate, Operating Leases	3.64%
Weighted Average Discount Rate, Finance Leases	4.62%
Operating Cash Flows Used for Operating Leases	$ 6.7
Operating Cash Flows Used for Finance Leases	0.6
Financing Cash Flows Used for Finance Leases	3.1	3.3	3.9
Non-cash Acquisitions Under Operating Leases	8.2
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	1,574.6	1,577
Other Property, Plant and Equipment	342.1	303.5
Total Property, Plant and Equipment	5,683.4	5,439.6
Accumulated Amortization	1,580.1	1,472.9
Net Property, Plant and Equipment Under Finance Leases	15.1	12.3
Other Liabilities, Noncurrent	18.4	32.5
Finance Lease Liability Due Within One Year	87.5	64.5
Total Obligations Under Finance Leases	15.1	12.3
Operating Lease Asset and Related Obligations
Operating Lease Assets	36.8	0
Operating Lease Noncurrent Liability	31	0
Operating Lease Liability Due Within One Year	5.8	0
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	36.8
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Finance Leases, 2020	3.8
Finance Leases, 2021	3.2
Finance Leases, 2022	2.6
Finance Leases, 2023	2.3
Finance Leases, 2024	1.8
Finance Leases, Later Years	3.8
Finance Leases, Total Future Minimum Lease Payments	17.5
Imputed Interest on Finance Leases	2.4
Total Obligations Under Finance Leases	15.1	12.3
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Operating Leases, 2020	7.3
Operating Leases, 2021	6.4
Operating Leases, 2022	6
Operating Leases, 2023	5.6
Operating Leases, 2024	4.8
Operating Leases, Later Years	12
Operating Leases, Total Future Minimum Lease Payments	42.1
Imputed Interest on Operating Leases	5.3
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	36.8
Finance Lease Future Minimum Lease Payments
Finance Leases, 2019		3.4
Finance Leases, 2020		2.6
Finance Leases, 2021		2
Finance Leases, 2022		1.6
Finance Leases, 2023		1.4
Finance Leases, Later Years		3.3
Finance Leases, Total Future Minimum Payments Due		14.3
Estimated Interest Element on Finance Leases		2
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		12.3
Operating Lease Future Minimum Lease Payments
Operating Leases, 2019		6.5
Operating Leases, 2020		6
Operating Leases, 2021		5
Operating Leases, 2022		4.6
Operating Leases, 2023		4.1
Operating Leases, Later Years		10.7
Operating Leases Total Future Minimum Lease Payments		36.9
Maximum Potential Loss
Max Potential Loss on Master Lease Agreements	4.2
Public Service Co Of Oklahoma [Member] | Finance Lease Assets [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	0.6	2.6
Other Property, Plant and Equipment	21.6	17.6
Total Property, Plant and Equipment	22.2	20.2
Accumulated Amortization	7.1	7.9
Public Service Co Of Oklahoma [Member] | Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Other Liabilities, Noncurrent	11.9	9.5
Finance Lease Liability Due Within One Year	3.2	2.8
Public Service Co Of Oklahoma [Member] | Operating Lease Assets [Member]
Operating Lease Asset and Related Obligations
Operating Lease Assets	36.8
Southwestern Electric Power Co [Member]
Lease Rental Costs
Operating Lease, Cost	8	6.5	5.3
Finance Lease Right-of-Use Asset Amortization	11	11.2	11.2
Interest Expense on Finance Leases	2.9	3.2	3.6
Total Lease Rental Costs	$ 21.9	20.9	20.1
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases	6 years 7 months 20 days
Weighted Average Remaining Lease Term, Finance Leases	5 years 1 month 28 days
Weighted Average Discount Rate, Operating Leases	3.76%
Weighted Average Discount Rate, Finance Leases	5.01%
Operating Cash Flows Used for Operating Leases	$ 7.9
Operating Cash Flows Used for Finance Leases	3
Financing Cash Flows Used for Finance Leases	11	11.5	$ 11.3
Non-cash Acquisitions Under Operating Leases	11.4
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	4,691.4	4,672.6
Other Property, Plant and Equipment	733.4	762.7
Total Property, Plant and Equipment	9,968.9	9,680.1
Accumulated Amortization	2,873.7	2,808.3
Net Property, Plant and Equipment Under Finance Leases	57.3	54.2
Other Liabilities, Noncurrent	86.2	102
Finance Lease Liability Due Within One Year	133.9	117.5
Total Obligations Under Finance Leases	57.6	60.8
Operating Lease Asset and Related Obligations
Operating Lease Noncurrent Liability	34.7	0
Operating Lease Liability Due Within One Year	6.5	0
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	41.2
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Finance Leases, 2020	12.9
Finance Leases, 2021	11.9
Finance Leases, 2022	10.6
Finance Leases, 2023	9.8
Finance Leases, 2024	14.2
Finance Leases, Later Years	6.8
Finance Leases, Total Future Minimum Lease Payments	66.2
Imputed Interest on Finance Leases	8.6
Total Obligations Under Finance Leases	57.6	60.8
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Operating Leases, 2020	8.6
Operating Leases, 2021	8.2
Operating Leases, 2022	7.6
Operating Leases, 2023	6.4
Operating Leases, 2024	5
Operating Leases, Later Years	11.8
Operating Leases, Total Future Minimum Lease Payments	47.6
Imputed Interest on Operating Leases	6.4
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	41.2
Finance Lease Future Minimum Lease Payments
Finance Leases, 2019		13.1
Finance Leases, 2020		11.5
Finance Leases, 2021		10.5
Finance Leases, 2022		9.4
Finance Leases, 2023		8.6
Finance Leases, Later Years		18.7
Finance Leases, Total Future Minimum Payments Due		71.8
Estimated Interest Element on Finance Leases		11
Estimated Present Value of Future Minimum Lease Payments on Finance Leases		60.8
Operating Lease Future Minimum Lease Payments
Operating Leases, 2019		7.4
Operating Leases, 2020		7.2
Operating Leases, 2021		6.7
Operating Leases, 2022		6.1
Operating Leases, 2023		5
Operating Leases, Later Years		11.7
Operating Leases Total Future Minimum Lease Payments		44.1
Maximum Potential Loss
Max Potential Loss on Master Lease Agreements	4.8
Southwestern Electric Power Co [Member] | Finance Lease Assets [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	34.1	34.3
Other Property, Plant and Equipment	51.6	119.8
Total Property, Plant and Equipment	85.7	154.1
Accumulated Amortization	28.4	99.9
Southwestern Electric Power Co [Member] | Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Other Liabilities, Noncurrent	47.1	50.6
Finance Lease Liability Due Within One Year	10.5	$ 10.2
Southwestern Electric Power Co [Member] | Operating Lease Assets [Member]
Operating Lease Asset and Related Obligations
Operating Lease Assets	$ 40.5

Financing Activities (Details)

Financing Activities (Details) - USD ($)		1 Months Ended		12 Months Ended
		Feb. 20, 2020	Jan. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Shares of Company
Beginning Balance, Shares			514,373,631	513,450,036	512,210,644	512,048,520
Issued				923,595	1,239,392	162,124
Ending Balance, Shares				514,373,631	513,450,036	512,210,644
Treasury Stock, Shares, Beginning Balance			20,204,160	20,204,160	20,205,046	20,336,592
Partners' Capital Account, Units, Treasury Units Reissued					(886)	(131,546)
Treasury Stock, Shares, Ending Balance				20,204,160	20,204,160	20,205,046
Long-term Debt
Senior Unsecured Notes				$ 21,180,700,000	$ 18,903,300,000
Pollution Control Bonds				1,998,800,000	1,643,800,000
Notes Payable				234,300,000	204,700,000
Securitization Bonds				1,025,100,000	1,111,400,000
Spent Nuclear Fuel Obligation				279,800,000	273,600,000
Junior Subordinated Notes				787,800,000	0
Other Long-term Debt				1,219,000,000	1,209,900,000
Total Long-term Debt Outstanding				26,725,500,000	23,346,700,000
Outstanding Long-term Debt
Principal Amount, 2020				1,598,700,000
Principal Amount, 2021				2,022,700,000
Principal Amount, 2022				3,014,600,000
Principal Amount, 2023				739,900,000
Principal Amount, 2024				706,500,000
Principal Amount, After 2024				18,863,100,000
Principal Amount, Total				26,945,500,000
Unamortized Discount, Net and Debt Issuance Costs				(220,000,000)
Total Long-term Debt Outstanding				26,725,500,000	23,346,700,000
Short-term Debt
Securitized Debt for Receivables				710,000,000	750,000,000
Commercial Paper				2,110,000,000	1,160,000,000
Notes Payable				18,300,000	0
Total Short-term Debt				$ 2,838,300,000	$ 1,910,000,000
Securitized Debt for Receivables				2.42%	2.16%
Comparative Accounts Receivable Information
Effective Interest Rates on Securitization of Accounts Receivable				2.42%	2.16%	1.22%
Net Uncollectible Accounts Receivable Written Off				$ 26,600,000	$ 27,600,000	$ 23,400,000
Customer Accounts Receivable Managed Portfolio
Accounts Receivable Retained Interest and Pledged as Collateral Less Uncollectible Accounts				841,800,000	972,500,000
Total Principal Outstanding				710,000,000	750,000,000
Delinquent Securitized Accounts Receivable				39,600,000	50,300,000
Bad Debt Reserves Related to Securitized Sale of Accounts Receivable				32,100,000	27,500,000
Unbilled Receivables Related to Securitization, Sale of Accounts Receivable				266,800,000	281,400,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				15,561,400,000	16,195,700,000	15,424,900,000
Financing Activities (Textuals)
Reaquired Pollution Control Bonds Held by Trustees				35,000,000
Repayments of Long-term Debt				1,220,800,000	2,782,000,000	3,087,900,000
Proceeds from Issuance of Long-term Debt				$ 4,536,600,000	4,945,700,000	3,854,100,000
Equity Units Issued				16,100,000
Per Unit Conversion for Equity Units				$ 50
Net Equity Units Issuance Proceeds				785,000,000
Principal Amounts of Junior Subordinated Debt				$ 1,000
Forward Equity Purchase Contract Date				2024
Equity Units Annual Distribution Rate				6.125%
Forward Equity Contract Payment Rate				2.725%
Stockholders' Equity, Other				$ (7,600,000)	23,100,000	55,800,000
Maximum Shares Issued Under Equity Units Conversion				9,701,860
Maximum Percentage Debt to Capitalization				67.50%
Restricted Net Assets				$ 13,200,000,000
Dividend Restrictions				1,741,400,000
Retained Earnings Available to Pay Dividends				7,200,000,000
Dividends Paid on Common Stock				(1,350,000,000)	$ (1,255,500,000)	(1,191,900,000)
Credit Facilities, Total				$ 4,000,000,000
Weighted Average Interest Rate of Commercial Paper Outstanding During Year				2.51%
Maximum Amount of Commercial Paper Outstanding				$ 2,200,000,000
Total Commitment From Bank Conduits To Finance Receivables				$ 750,000,000
Minimum [Member]
Financing Activities (Textuals)
AEP Share Price for Equity Unit Conversion				$ 82.98
Shares Per Equity Unit				0.5021
Maximum [Member]
Financing Activities (Textuals)
AEP Share Price for Equity Unit Conversion				$ 99.58
Shares Per Equity Unit				0.6026
Commercial Paper [Member]
Short-term Debt
Debt, Weighted Average Interest Rate				2.10%	2.96%
Loans Payable [Member]
Short-term Debt
Debt, Weighted Average Interest Rate				3.29%	0.00%
AEP Texas Inc. [Member]
Long-term Debt
Senior Unsecured Notes				$ 3,090,900,000	$ 2,398,400,000
Pollution Control Bonds				490,300,000	490,900,000
Securitization Bonds				776,800,000	791,200,000
Other Long-term Debt				200,400,000	200,800,000
Total Long-term Debt Outstanding				4,558,400,000	3,881,300,000
Outstanding Long-term Debt
Principal Amount, 2020				392,100,000
Principal Amount, 2021				88,700,000
Principal Amount, 2022				716,000,000
Principal Amount, 2023				218,500,000
Principal Amount, 2024				96,000,000
Principal Amount, After 2024				3,081,400,000
Principal Amount, Total				4,592,700,000
Unamortized Discount, Net and Debt Issuance Costs				(34,300,000)
Total Long-term Debt Outstanding				4,558,400,000	3,881,300,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				1,551,600,000	1,493,000,000
Financing Activities (Textuals)
Repayments of Long-term Debt				401,800,000	266,100,000	323,100,000
Proceeds from Issuance of Long-term Debt				$ 1,070,400,000	494,000,000	$ 749,600,000
Maximum Percentage Debt to Capitalization				67.50%
Dividend Restrictions				$ 385,000,000
AEP Texas Inc. [Member] | Utility [Member]
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				390,700,000	390,600,000
Maximum Loans to Money Pool				213,100,000	106,900,000
Average Borrowings from Money Pool				239,300,000	176,000,000
Average Loans to Money Pool				194,400,000	47,100,000
Net Loans (Borrowings) to/from Money Pool				199,700,000	(216,000,000)
Authorized Short Term Borrowing Limit				$ 500,000,000	$ 500,000,000
Maximum and Minimum Interest Rates
Maximum Interest Rate				3.43%	2.97%	1.85%
Minimum Interest Rate				1.77%	1.81%	0.92%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				2.63%	2.26%	1.29%
Average Interest Rate For Funds Loaned				2.03%	2.29%	1.26%
AEP Texas Inc. [Member] | Nonutility [Member]
Maximum Interest Rate For Funds Loaned				3.02%	2.97%	1.85%
Minimum Interest Rate for Funds Loaned				1.91%	1.83%	0.00%
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Loans to Money Pool				$ 8,000,000	$ 8,400,000
Average Loans to Money Pool				7,700,000	8,100,000
Net Loans (Borrowings) to/from Money Pool				$ 7,500,000	$ 8,000,000
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Loaned				2.56%	2.36%	1.32%
AEP Transmission Co [Member]
Long-term Debt
Senior Unsecured Notes				$ 3,427,300,000	$ 2,823,000,000
Total Long-term Debt Outstanding				3,427,300,000	2,823,000,000
Outstanding Long-term Debt
Principal Amount, 2020				0
Principal Amount, 2021				50,000,000
Principal Amount, 2022				104,000,000
Principal Amount, 2023				60,000,000
Principal Amount, 2024				95,000,000
Principal Amount, After 2024				3,156,000,000
Principal Amount, Total				3,465,000,000
Unamortized Discount, Net and Debt Issuance Costs				(37,700,000)
Total Long-term Debt Outstanding				3,427,300,000	2,823,000,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				1,042,100,000	832,000,000
Financing Activities (Textuals)
Repayments of Long-term Debt				85,000,000	50,000,000	$ 0
Proceeds from Issuance of Long-term Debt				688,000,000	321,000,000	$ 617,600,000
Sub-Limit of Secured Debt				$ 50,000,000
Maximum Percentage of Consolidated Tangible Net Assets				10.00%
Tangible Capital to Tangible Assets				1.60%
Maximum Percentage Debt to Capitalization				67.50%
Dividend Restrictions				$ 0
AEP Transmission Co [Member] | Utility [Member]
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				374,900,000	371,300,000
Maximum Loans to Money Pool				244,400,000	276,400,000
Average Borrowings from Money Pool				152,000,000	177,900,000
Average Loans to Money Pool				52,800,000	58,400,000
Net Loans (Borrowings) to/from Money Pool				(119,000,000)	35,800,000
Authorized Short Term Borrowing Limit				$ 795,000,000	$ 795,000,000
Maximum and Minimum Interest Rates
Maximum Interest Rate				3.43%	2.97%	1.85%
Minimum Interest Rate				1.77%	1.81%	0.92%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				2.64%	2.27%	1.36%
Average Interest Rate For Funds Loaned				2.41%	2.10%	1.27%
AEP Transmission Co [Member] | Direct Borrowing [Member]
Maximum Interest Rate for Funds Borrowed				3.02%	2.97%	1.85%
Minimum Interest Rate For Funds Borrowed				1.91%	1.76%	0.92%
Maximum Interest Rate For Funds Loaned				3.02%	2.97%	1.85%
Minimum Interest Rate for Funds Loaned				1.91%	1.76%	0.92%
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				$ 1,300,000	$ 1,200,000
Maximum Loans to Money Pool				153,500,000	104,700,000
Average Borrowings from Money Pool				1,300,000	1,100,000
Average Loans to Money Pool				68,000,000	49,800,000
Borrowings from Parent				1,300,000	1,200,000
Loans to Parent				68,700,000	16,900,000
Authorized Short Term Borrowing Limit				$ 75,000,000	$ 75,000,000
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				2.55%	2.36%	1.33%
Average Interest Rate For Funds Loaned				2.51%	2.36%	1.36%
Appalachian Power Co [Member]
Long-term Debt
Senior Unsecured Notes				$ 3,442,700,000	$ 3,047,300,000
Pollution Control Bonds				546,100,000	616,000,000
Securitization Bonds				248,300,000	272,300,000
Other Long-term Debt				126,700,000	127,000,000
Total Long-term Debt Outstanding				4,363,800,000	4,062,600,000
Outstanding Long-term Debt
Principal Amount, 2020				215,600,000
Principal Amount, 2021				393,000,000
Principal Amount, 2022				355,400,000
Principal Amount, 2023				26,600,000
Principal Amount, 2024				113,500,000
Principal Amount, After 2024				3,296,900,000
Principal Amount, Total				4,401,000,000
Unamortized Discount, Net and Debt Issuance Costs				(37,200,000)
Total Long-term Debt Outstanding				4,363,800,000	4,062,600,000
Accounts Receivable and Accrued Unbilled Revenue
Accounts Receivable and Accrued Unbilled Revenues				120,900,000	133,300,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				2,911,100,000	2,993,200,000
Proceeds on Sale of Receivables to AEP Credit
Proceeds from Sale of Receivables to AEP Credit				1,310,300,000	1,421,000,000	$ 1,372,800,000
Financing Activities (Textuals)
Repayments of Long-term Debt				180,500,000	124,000,000	377,900,000
Proceeds from Issuance of Long-term Debt				$ 478,200,000	203,200,000	$ 320,900,000
Maximum Percentage Debt to Capitalization				67.50%
Dividend Restrictions				$ 26,300,000
Appalachian Power Co [Member] | Utility [Member]
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				270,000,000	295,500,000
Maximum Loans to Money Pool				232,200,000	23,700,000
Average Borrowings from Money Pool				115,900,000	175,300,000
Average Loans to Money Pool				51,900,000	23,300,000
Net Loans (Borrowings) to/from Money Pool				(214,600,000)	(182,600,000)
Authorized Short Term Borrowing Limit				$ 500,000,000	$ 600,000,000
Maximum and Minimum Interest Rates
Maximum Interest Rate				3.43%	2.97%	1.85%
Minimum Interest Rate				1.77%	1.81%	0.92%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				2.45%	2.26%	1.28%
Average Interest Rate For Funds Loaned				2.66%	2.21%	1.29%
Indiana Michigan Power Co [Member]
Long-term Debt
Senior Unsecured Notes				$ 2,150,700,000	$ 2,149,000,000
Pollution Control Bonds				240,000,000	264,500,000
Notes Payable				168,700,000	135,800,000
Spent Nuclear Fuel Obligation				279,800,000	273,600,000
Other Long-term Debt				211,000,000	212,500,000
Total Long-term Debt Outstanding				3,050,200,000	3,035,400,000
Outstanding Long-term Debt
Principal Amount, 2020				139,700,000
Principal Amount, 2021				291,500,000
Principal Amount, 2022				26,800,000
Principal Amount, 2023				259,200,000
Principal Amount, 2024				4,200,000
Principal Amount, After 2024				2,355,300,000
Principal Amount, Total				3,076,700,000
Unamortized Discount, Net and Debt Issuance Costs				(26,500,000)
Total Long-term Debt Outstanding				3,050,200,000	3,035,400,000
Accounts Receivable and Accrued Unbilled Revenue
Accounts Receivable and Accrued Unbilled Revenues				141,800,000	152,900,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				2,308,100,000	2,381,000,000
Proceeds on Sale of Receivables to AEP Credit
Proceeds from Sale of Receivables to AEP Credit				1,824,200,000	1,843,000,000	$ 1,612,900,000
Financing Activities (Textuals)
Repayments of Long-term Debt				117,100,000	884,900,000	260,700,000
Proceeds from Issuance of Long-term Debt				$ 123,300,000	1,168,100,000	$ 530,100,000
Maximum Percentage Debt to Capitalization				67.50%
Dividend Restrictions				$ 524,500,000
Indiana Michigan Power Co [Member] | Utility [Member]
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				158,800,000	322,100,000
Maximum Loans to Money Pool				66,000,000	657,800,000
Average Borrowings from Money Pool				71,500,000	255,500,000
Average Loans to Money Pool				16,200,000	110,700,000
Net Loans (Borrowings) to/from Money Pool				(101,200,000)	11,600,000
Authorized Short Term Borrowing Limit				$ 500,000,000	$ 500,000,000
Maximum and Minimum Interest Rates
Maximum Interest Rate				3.43%	2.97%	1.85%
Minimum Interest Rate				1.77%	1.81%	0.92%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				2.34%	2.16%	1.27%
Average Interest Rate For Funds Loaned				2.60%	2.08%	1.29%
Ohio Power Co [Member]
Long-term Debt
Senior Unsecured Notes				$ 2,081,000,000	$ 1,635,500,000
Pollution Control Bonds				0	32,300,000
Securitization Bonds				0	47,800,000
Other Long-term Debt				1,000,000	1,000,000
Total Long-term Debt Outstanding				2,082,000,000	1,716,600,000
Outstanding Long-term Debt
Principal Amount, 2020				100,000
Principal Amount, 2021				500,100,000
Principal Amount, 2022				100,000
Principal Amount, 2023				100,000
Principal Amount, 2024				100,000
Principal Amount, After 2024				1,600,500,000
Principal Amount, Total				2,101,000,000
Unamortized Discount, Net and Debt Issuance Costs				(19,000,000)
Total Long-term Debt Outstanding				2,082,000,000	1,716,600,000
Accounts Receivable and Accrued Unbilled Revenue
Accounts Receivable and Accrued Unbilled Revenues				330,300,000	395,200,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				2,748,800,000	3,079,900,000
Proceeds on Sale of Receivables to AEP Credit
Proceeds from Sale of Receivables to AEP Credit				2,293,600,000	2,674,500,000	$ 2,339,000,000
Financing Activities (Textuals)
Reaquired Pollution Control Bonds Held by Trustees				35,000,000
Repayments of Long-term Debt				80,300,000	397,100,000	46,400,000
Proceeds from Issuance of Long-term Debt				444,300,000	392,800,000	$ 0
Dividend Restrictions				0
Ohio Power Co [Member] | Utility [Member]
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				291,200,000	270,800,000
Maximum Loans to Money Pool				178,600,000	225,000,000
Average Borrowings from Money Pool				129,200,000	167,800,000
Average Loans to Money Pool				50,100,000	189,400,000
Net Loans (Borrowings) to/from Money Pool				(131,000,000)	(114,100,000)
Authorized Short Term Borrowing Limit				$ 500,000,000	$ 500,000,000
Maximum and Minimum Interest Rates
Maximum Interest Rate				3.43%	2.97%	1.85%
Minimum Interest Rate				1.77%	1.81%	0.92%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				2.67%	2.18%	1.37%
Average Interest Rate For Funds Loaned				2.68%	2.47%	0.98%
Public Service Co Of Oklahoma [Member]
Shares of Company
Beginning Balance, Shares			10,482,000	10,482,000
Ending Balance, Shares				10,482,000	10,482,000
Long-term Debt
Senior Unsecured Notes				$ 1,245,600,000	$ 1,144,900,000
Pollution Control Bonds				12,700,000	12,600,000
Other Long-term Debt				127,900,000	129,500,000
Total Long-term Debt Outstanding				1,386,200,000	1,287,000,000
Outstanding Long-term Debt
Principal Amount, 2020				13,200,000
Principal Amount, 2021				250,500,000
Principal Amount, 2022				125,500,000
Principal Amount, 2023				600,000
Principal Amount, 2024				600,000
Principal Amount, After 2024				1,001,400,000
Principal Amount, Total				1,391,800,000
Unamortized Discount, Net and Debt Issuance Costs				(5,600,000)
Total Long-term Debt Outstanding				1,386,200,000	1,287,000,000
Accounts Receivable and Accrued Unbilled Revenue
Accounts Receivable and Accrued Unbilled Revenues				101,100,000	109,700,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				1,512,800,000	1,536,400,000
Proceeds on Sale of Receivables to AEP Credit
Proceeds from Sale of Receivables to AEP Credit				1,442,500,000	1,484,600,000	$ 1,337,000,000
Financing Activities (Textuals)
Repayments of Long-term Debt				250,500,000	500,000	500,000
Proceeds from Issuance of Long-term Debt				$ 349,500,000	0	$ 0
Maximum Percentage Debt to Capitalization				67.50%
Dividend Restrictions				$ 153,000,000
Public Service Co Of Oklahoma [Member] | Utility [Member]
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				140,500,000	193,700,000
Maximum Loans to Money Pool				215,600,000	31,800,000
Average Borrowings from Money Pool				63,900,000	104,500,000
Average Loans to Money Pool				98,300,000	12,900,000
Net Loans (Borrowings) to/from Money Pool				38,800,000	(105,500,000)
Authorized Short Term Borrowing Limit				$ 300,000,000	$ 300,000,000
Maximum and Minimum Interest Rates
Maximum Interest Rate				3.43%	2.97%	1.85%
Minimum Interest Rate				1.77%	1.81%	0.92%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				2.85%	2.27%	1.32%
Average Interest Rate For Funds Loaned				2.27%	1.98%	0.00%
Southwestern Electric Power Co [Member]
Long-term Debt
Senior Unsecured Notes				$ 2,428,900,000	$ 2,427,000,000
Pollution Control Bonds				0	53,500,000
Notes Payable				65,600,000	68,900,000
Other Long-term Debt				161,100,000	164,000,000
Total Long-term Debt Outstanding				2,655,600,000	2,713,400,000
Outstanding Long-term Debt
Principal Amount, 2020				121,200,000
Principal Amount, 2021				6,200,000
Principal Amount, 2022				281,200,000
Principal Amount, 2023				6,200,000
Principal Amount, 2024				31,200,000
Principal Amount, After 2024				2,231,700,000
Principal Amount, Total				2,677,700,000
Unamortized Discount, Net and Debt Issuance Costs				(22,100,000)
Total Long-term Debt Outstanding				2,655,600,000	2,713,400,000
Short-term Debt
Notes Payable				18,300,000	0
Accounts Receivable and Accrued Unbilled Revenue
Accounts Receivable and Accrued Unbilled Revenues				125,200,000	150,300,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				1,799,200,000	1,817,000,000
Proceeds on Sale of Receivables to AEP Credit
Proceeds from Sale of Receivables to AEP Credit				1,618,500,000	1,736,100,000	$ 1,563,400,000
Financing Activities (Textuals)
Repayments of Long-term Debt				59,700,000	794,500,000	353,700,000
Proceeds from Issuance of Long-term Debt				$ 0	1,065,700,000	114,600,000
Maximum Percentage Debt to Capitalization				67.50%
Dividend Restrictions				$ 534,500,000
Dividends Paid on Common Stock				(3,300,000)	(4,300,000)	$ (13,600,000)
Southwestern Electric Power Co [Member] | Utility [Member]
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				105,100,000	200,100,000
Maximum Loans to Money Pool				81,400,000	533,700,000
Average Borrowings from Money Pool				53,300,000	143,200,000
Average Loans to Money Pool				13,600,000	268,100,000
Net Loans (Borrowings) to/from Money Pool				(59,900,000)	81,400,000
Authorized Short Term Borrowing Limit				$ 350,000,000	$ 350,000,000
Maximum and Minimum Interest Rates
Maximum Interest Rate				3.43%	2.97%	1.85%
Minimum Interest Rate				1.77%	1.81%	0.92%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				2.72%	2.31%	1.28%
Average Interest Rate For Funds Loaned				2.22%	2.00%	0.98%
Southwestern Electric Power Co [Member] | Nonutility [Member]
Maximum Interest Rate For Funds Loaned				3.02%	2.97%	1.85%
Minimum Interest Rate for Funds Loaned				1.91%	1.83%	0.00%
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Loans to Money Pool				$ 2,100,000	$ 2,000,000
Average Loans to Money Pool				2,000,000	2,000,000
Net Loans (Borrowings) to/from Money Pool				$ 2,100,000	$ 2,000,000
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Loaned				2.55%	2.36%	1.32%
Southwestern Electric Power Co [Member] | Loans Payable [Member]
Short-term Debt
Debt, Weighted Average Interest Rate				3.29%	0.00%
Senior Notes [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2019
Maturity Date High				2050
Weighted Average Interest Rate				4.29%
Senior Notes [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.15%	2.15%
Senior Notes [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				8.13%	8.13%
Senior Notes [Member] | AEP Texas Inc. [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2019
Maturity Date High				2050
Weighted Average Interest Rate				4.01%
Senior Notes [Member] | AEP Texas Inc. [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.40%	2.40%
Senior Notes [Member] | AEP Texas Inc. [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				6.76%	6.76%
Senior Notes [Member] | AEP Transmission Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2019
Maturity Date High				2049
Weighted Average Interest Rate				3.86%
Senior Notes [Member] | AEP Transmission Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.10%	2.68%
Senior Notes [Member] | AEP Transmission Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				5.52%	5.52%
Senior Notes [Member] | Appalachian Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2021
Maturity Date High				2049
Weighted Average Interest Rate				5.12%
Senior Notes [Member] | Appalachian Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.30%	3.30%
Senior Notes [Member] | Appalachian Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				7.00%	7.00%
Senior Notes [Member] | Indiana Michigan Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2023
Maturity Date High				2048
Weighted Average Interest Rate				4.38%
Senior Notes [Member] | Indiana Michigan Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.20%	3.20%
Senior Notes [Member] | Indiana Michigan Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				6.05%	6.05%
Senior Notes [Member] | Ohio Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2021
Maturity Date High				2049
Weighted Average Interest Rate				5.20%
Senior Notes [Member] | Ohio Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				4.00%	4.15%
Senior Notes [Member] | Ohio Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				6.60%	6.60%
Senior Notes [Member] | Public Service Co Of Oklahoma [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2019
Maturity Date High				2049
Weighted Average Interest Rate				4.55%
Senior Notes [Member] | Public Service Co Of Oklahoma [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.05%	3.05%
Senior Notes [Member] | Public Service Co Of Oklahoma [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				6.625%	6.625%
Senior Notes [Member] | Southwestern Electric Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2022
Maturity Date High				2048
Weighted Average Interest Rate				4.04%
Senior Notes [Member] | Southwestern Electric Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.75%	2.75%
Senior Notes [Member] | Southwestern Electric Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				6.20%	6.20%
Pollution Control Bonds [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low	[1]			2019
Maturity Date High	[1]			2038
Weighted Average Interest Rate				2.75%
Pollution Control Bonds [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.35%	1.60%
Pollution Control Bonds [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				5.38%	6.30%
Pollution Control Bonds [Member] | AEP Texas Inc. [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2020
Maturity Date High				2030
Weighted Average Interest Rate				3.63%
Pollution Control Bonds [Member] | AEP Texas Inc. [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.75%	1.75%
Pollution Control Bonds [Member] | AEP Texas Inc. [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				4.55%	6.30%
Pollution Control Bonds [Member] | Appalachian Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low	[1]			2019
Maturity Date High	[1]			2038
Weighted Average Interest Rate				2.64%
Pollution Control Bonds [Member] | Appalachian Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.67%	1.70%
Pollution Control Bonds [Member] | Appalachian Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				5.38%	5.38%
Pollution Control Bonds [Member] | Indiana Michigan Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low	[1]			2019
Maturity Date High	[1]			2025
Weighted Average Interest Rate				2.55%
Pollution Control Bonds [Member] | Indiana Michigan Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.79%	1.81%
Pollution Control Bonds [Member] | Indiana Michigan Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.05%	3.05%
Pollution Control Bonds [Member] | Ohio Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2038
Maturity Date High				2038
Pollution Control Bonds [Member] | Ohio Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate					5.80%
Pollution Control Bonds [Member] | Ohio Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate					5.80%
Pollution Control Bonds [Member] | Public Service Co Of Oklahoma [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2020
Maturity Date High				2020
Weighted Average Interest Rate				4.45%
Pollution Control Bonds [Member] | Public Service Co Of Oklahoma [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				4.45%	4.45%
Pollution Control Bonds [Member] | Public Service Co Of Oklahoma [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				4.45%	4.45%
Pollution Control Bonds [Member] | Southwestern Electric Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2019
Maturity Date High				2019
Pollution Control Bonds [Member] | Southwestern Electric Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate					1.60%
Pollution Control Bonds [Member] | Southwestern Electric Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate					1.60%
Notes Payable, Other Payables [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2019
Maturity Date High				2032
Weighted Average Interest Rate				3.27%
Notes Payable, Other Payables [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.42%	3.20%
Notes Payable, Other Payables [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				6.37%	6.37%
Notes Payable, Other Payables [Member] | Indiana Michigan Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2019
Maturity Date High				2024
Weighted Average Interest Rate				2.49%
Notes Payable, Other Payables [Member] | Indiana Michigan Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.42%	3.20%
Notes Payable, Other Payables [Member] | Indiana Michigan Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.80%	3.38%
Notes Payable, Other Payables [Member] | Indiana Michigan Power Co [Member] | Subsequent Event [Member]
Financing Activities (Textuals)
Repayments of Long-term Debt		$ 5,000,000	$ 8,000,000
Notes Payable, Other Payables [Member] | Southwestern Electric Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2024
Maturity Date High				2032
Weighted Average Interest Rate				5.26%
Notes Payable, Other Payables [Member] | Southwestern Electric Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				4.58%	4.58%
Notes Payable, Other Payables [Member] | Southwestern Electric Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				6.37%	6.37%
Securitization Bonds [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low	[2]			2019
Maturity Date High	[2]			2029
Weighted Average Interest Rate				3.23%
Securitization Bonds [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.98%	1.98%
Securitization Bonds [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				5.31%	5.31%
Securitization Bonds [Member] | AEP Texas Inc. [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low	[2]			2020
Maturity Date High	[2]			2029
Weighted Average Interest Rate				3.25%
Securitization Bonds [Member] | AEP Texas Inc. [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.98%	1.98%
Securitization Bonds [Member] | AEP Texas Inc. [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				5.31%	5.31%
Securitization Bonds [Member] | AEP Texas Inc. [Member] | Subsequent Event [Member]
Financing Activities (Textuals)
Repayments of Long-term Debt		3,000,000	111,000,000
Securitization Bonds [Member] | Appalachian Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low	[2]			2023
Maturity Date High	[2]			2028
Weighted Average Interest Rate				3.17%
Securitization Bonds [Member] | Appalachian Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.008%	2.008%
Securitization Bonds [Member] | Appalachian Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.772%	3.772%
Securitization Bonds [Member] | Appalachian Power Co [Member] | Subsequent Event [Member]
Financing Activities (Textuals)
Repayments of Long-term Debt		$ 12,000,000
Securitization Bonds [Member] | Ohio Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low	[2]			2019
Maturity Date High	[2]			2019
Securitization Bonds [Member] | Ohio Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate					2.049%
Securitization Bonds [Member] | Ohio Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate					2.049%
Junior Subordinated Notes [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2022
Maturity Date High				2022
Weighted Average Interest Rate				3.40%
Financing Activities (Textuals)
Proceeds from Issuance of Debt				$ 805,000,000
Junior Subordinated Notes [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.40%
Junior Subordinated Notes [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.40%
Other Long Term Debt [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2019
Maturity Date High				2059
Weighted Average Interest Rate				3.03%
Other Long Term Debt [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.15%	1.15%
Other Long Term Debt [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				13.718%	13.718%
Other Long Term Debt [Member] | AEP Texas Inc. [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2019
Maturity Date High				2059
Weighted Average Interest Rate				3.06%
Other Long Term Debt [Member] | AEP Texas Inc. [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.05%	3.94%
Other Long Term Debt [Member] | AEP Texas Inc. [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				4.50%	4.50%
Other Long Term Debt [Member] | Appalachian Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2019
Maturity Date High				2026
Weighted Average Interest Rate				3.14%
Other Long Term Debt [Member] | Appalachian Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.97%	3.74%
Other Long Term Debt [Member] | Appalachian Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				13.718%	13.718%
Other Long Term Debt [Member] | Indiana Michigan Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2021
Maturity Date High				2025
Weighted Average Interest Rate				3.09%
Other Long Term Debt [Member] | Indiana Michigan Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.93%	3.66%
Other Long Term Debt [Member] | Indiana Michigan Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				6.00%	6.00%
Other Long Term Debt [Member] | Ohio Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2028
Maturity Date High				2028
Weighted Average Interest Rate				1.15%
Other Long Term Debt [Member] | Ohio Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.15%	1.15%
Other Long Term Debt [Member] | Ohio Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.15%	1.15%
Other Long Term Debt [Member] | Public Service Co Of Oklahoma [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2019
Maturity Date High				2027
Weighted Average Interest Rate				3.19%
Other Long Term Debt [Member] | Public Service Co Of Oklahoma [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.00%	3.00%
Other Long Term Debt [Member] | Public Service Co Of Oklahoma [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.20%	3.72%
Other Long Term Debt [Member] | Southwestern Electric Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2020
Maturity Date High				2035
Weighted Average Interest Rate				3.55%
Other Long Term Debt [Member] | Southwestern Electric Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.08%	3.75%
Other Long Term Debt [Member] | Southwestern Electric Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				4.68%	4.68%
Other Long Term Debt [Member] | Transource Energy [Member] | Subsequent Event [Member]
Financing Activities (Textuals)
Proceeds from Issuance of Long-term Debt			$ 4,000,000
Due Date			2023
Servicing Contracts [Member] | Appalachian Power Co [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				$ 7,400,000	$ 7,000,000	$ 5,600,000
Servicing Contracts [Member] | Indiana Michigan Power Co [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				11,100,000	9,200,000	6,700,000
Servicing Contracts [Member] | Ohio Power Co [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				27,100,000	26,300,000	21,700,000
Servicing Contracts [Member] | Public Service Co Of Oklahoma [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				7,800,000	7,900,000	7,000,000
Servicing Contracts [Member] | Southwestern Electric Power Co [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				10,200,000	8,900,000	7,200,000
Retained Earnings [Member]
Financing Activities (Textuals)
Stockholders' Equity, Other				62,000,000
Dividends Paid on Common Stock				$ (1,300,000,000)	$ (1,300,000,000)	$ (1,200,000,000)
[1]	Certain Pollution Control Bonds are subject to redemption earlier than the maturity date. Consequently, these bonds have been classified for maturity purposes as Long-term Debt Due Within One Year - Nonaffiliated on the balance sheets.
[2]	Dates represent the scheduled final payment dates for the securitization bonds. The legal maturity date is one to two years later. These bonds have been classified for maturity and repayment purposes based on the scheduled final payment date.

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock Based Compensation (Textuals)
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	10,000,000
Number of Shares Remaining Available for Issuance Under the AEP Long-Term Incentive Plan	7,667,992
Reduction in Aggregate Common Shares Authorized Per Share Issued Pursuant to Stock Options or Stock Appreciation Rights	0.286
Performance Units and AEP Career Shares Reinvested Dividends Portion For [Member]
Performance Units
Awarded Units	66,400	80,200	74,600
Weighted Average Grant Date Fair Value, Granted	$ 88.73	$ 70.58	$ 72.35
Vesting Period	(b)	(b)	(b)
Restricted Stock Units Including Units Awarded for Dividends
Weighted Average Grant Date Fair Value	$ 88.73	$ 70.58	$ 72.35
Status of Nonvested Restricted Shares and Restricted Stock Units
Weighted Average Grant Date Fair Value, Granted	88.73	70.58	72.35
Stock Unit Accumulation Plan for Non-employee Directors
Weighted Average Grant Date Fair Value	$ 88.73	$ 70.58	$ 72.35
Stock Based Compensation [Member]
Compensation Cost and Actual Tax Benefit Realized for the Tax Deductions from Compensation Cost for Share-based Payment Arrangements
Compensation Cost for Share-based Payment Arrangements	$ 57.9	$ 53.2	$ 79.5
Actual Tax Benefit Realized	8.4	7.7	18.9
Total Compensation Cost Capitalized	20	$ 19.7	$ 26.4
Stock Based Compensation (Textuals)
Total Unrecognized Compensation Cost Related to Unvested Share-based Compensation Arrangements Granted	$ 73
Weighted-average Period of Unrecognized Compensation Costs (in years)	1.43 years
Stock Unit Accumulation Plan for Non Employee Directors [Member]
Performance Units
Weighted Average Grant Date Fair Value, Granted	$ 89.13	$ 70.41	$ 70.79
Restricted Stock Units Including Units Awarded for Dividends
Awarded Units	10,000	11,400	14,800
Weighted Average Grant Date Fair Value	$ 89.13	$ 70.41	$ 70.79
Status of Nonvested Restricted Shares and Restricted Stock Units
Shares/Units, Granted	10,000	11,400	14,800
Weighted Average Grant Date Fair Value, Granted	$ 89.13	$ 70.41	$ 70.79
Stock Unit Accumulation Plan for Non-employee Directors
Awarded Units	10,000	11,400	14,800
Weighted Average Grant Date Fair Value	$ 89.13	$ 70.41	$ 70.79
Stock Based Compensation (Textuals)
Shares/Units, Granted	10,000	11,400	14,800
Number of Years After Termination of Board Service Participant Can Elect to Have Stock Units Paid in Cash	10 years
Restricted Stock Units (RSUs) [Member]
Performance Units
Weighted Average Grant Date Fair Value, Granted	$ 81.57	$ 67.96	$ 65.26
Restricted Stock Units Including Units Awarded for Dividends
Awarded Units	304,800	260,000	255,800
Weighted Average Grant Date Fair Value	$ 81.57	$ 67.96	$ 65.26
Total Fair Value and Total Intrinsic Value of Restricted Shares and Restricted Stock Units Vested
Fair Value of Restricted Shares and Restricted Stock Units Vested	$ 16.3	$ 16.6	$ 16.1
Intrinsic Value of Restricted Shares and Restricted Stock Units Vested	$ 21.6	$ 19.2	$ 20
Status of Nonvested Restricted Shares and Restricted Stock Units
Nonvested, Shares/Units, Beginning Balance	489,100
Nonvested, Weighted Average Grant Date Fair Value, Beginning of Period	$ 66.01
Shares/Units, Granted	304,800	260,000	255,800
Weighted Average Grant Date Fair Value, Granted	$ 81.57	$ 67.96	$ 65.26
Shares/Units, Vested	(253,700)
Weighted Average Grant Date Fair Value, Vested	$ 64.44
Shares/Units, Forfeited	(23,300)
Weighted Average Grant Date Fair Value, Shares/Units, Forfeited	$ 70.27
Nonvested, Shares/Units, Ending Balance	516,900	489,100
Nonvested, Weighted Average Grant Date Fair Value, End of Period	$ 75.55	$ 66.01
Stock Unit Accumulation Plan for Non-employee Directors
Awarded Units	304,800	260,000	255,800
Weighted Average Grant Date Fair Value	$ 81.57	$ 67.96	$ 65.26
Stock Based Compensation (Textuals)
Maximum Contractual Term of Outstanding Restricted Stock Units (in months)	40 months
Shares/Units, Granted	304,800	260,000	255,800
Total Aggregate Intrinsic Value of Nonvested Shares	$ 49
Weighted Average Remaining Contractual Life of Nonvested Shares (in years)	1.79 years
Performance Units [Member]
Performance Units
Awarded Units	535,000	581,400	590,700
Weighted Average Grant Date Fair Value, Granted	$ 83.21	$ 67.21	$ 69.78
Vesting Period (in years)	3 years	3 years	3 years
Certified Performance Scores and Units Earned
Certified Performance Score	132.70%	136.70%	164.80%
Performance Units Earned	792,897	820,780	956,055
Performance Units Manditorily Deferred as AEP Career Shares	10,063	11,248	20,213
Performance Units Voluntarily Deferred into the Incentive Compensation Deferral Program	49,392	56,826	47,177
Share Based Compensation Performance Units to be Settled in Shares	733,442
Performance Units to be Paid in Cash		752,706	888,665
Cash Payouts
Cash Payouts for Performance Units	$ 58.3	$ 66.9	$ 64.9
Restricted Stock Units Including Units Awarded for Dividends
Weighted Average Grant Date Fair Value	$ 83.21	$ 67.21	$ 69.78
Status of Nonvested Restricted Shares and Restricted Stock Units
Weighted Average Grant Date Fair Value, Granted	83.21	67.21	69.78
Stock Unit Accumulation Plan for Non-employee Directors
Weighted Average Grant Date Fair Value	$ 83.21	$ 67.21	$ 69.78
Stock Based Compensation (Textuals)
Performance Score by HR Committee, Lower Range	0.00%
Performance Score by HR Committee, Higher Range	200.00%
Equity Payouts For Career Share Distributions	$ 6.6	$ 5.1	$ 0.4
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	2 years 10 months 13 days	2 years 10 months 13 days	2 years 10 months 9 days
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum	14.83%	14.77%	15.65%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum	25.57%	26.72%	27.19%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	2.49%	2.34%	1.44%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	0.00%	0.00%	0.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Weighted Average Volatility Rate	17.39%	17.90%	19.07%
Performance Units and Reinvested Dividends [Member]
Share Based Compensation Performance Units Converted to Shares	733,000
Performance Units
Weighted Average Grant Date Fair Value, Granted	$ 80.30
Restricted Stock Units Including Units Awarded for Dividends
Awarded Units	582,500
Weighted Average Grant Date Fair Value	$ 80.30
Status of Nonvested Restricted Shares and Restricted Stock Units
Nonvested, Shares/Units, Beginning Balance	1,171,300
Nonvested, Weighted Average Grant Date Fair Value, Beginning of Period	$ 66.01
Shares/Units, Granted	582,500
Weighted Average Grant Date Fair Value, Granted	$ 80.30
Shares/Units, Vested	(597,500)
Weighted Average Grant Date Fair Value, Vested	$ 65.42
Shares/Units, Forfeited	(42,900)
Weighted Average Grant Date Fair Value, Shares/Units, Forfeited	$ 70.32
Nonvested, Shares/Units, Ending Balance	1,113,400	1,171,300
Nonvested, Weighted Average Grant Date Fair Value, End of Period	$ 73.64	$ 66.01
Stock Unit Accumulation Plan for Non-employee Directors
Awarded Units	582,500
Weighted Average Grant Date Fair Value	$ 80.30
Stock Based Compensation (Textuals)
Shares/Units, Granted	582,500

Related Party Transactions (Det

Related Party Transactions (Details) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2019MW	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Affiliated Revenues and Purchases
Affiliated Revenues		$ 0	$ 0	$ 0
Charitable Contribution to AEP Foundation [Abstract]
Related Party Charitable Contribuions to AEP Foundation		50
Appalachian Power Co. to AEP Transmission Co [Member]
Joint License Agreement
Joint License Agreement		$ 0.2	0	0
Indiana Michigan Power Co to Kentucky Power Co [Member]
Related Party Transactions (Textuals)
Percentage of Power Sold under Unit Power Agreement		30.00%
AEP Generating Co to Indiana Michigan Power Co [Member]
Cook Coal Terminal
Coal Transloading Services		$ 13	12	10
Railcar Maintenance		$ 1.3	1.5	1.3
AEP Generating Co to Kentucky Power Co [Member]
Related Party Transactions (Textuals)
Percentage of Power Sold under Unit Power Agreement		30.00%
AEP Generating Co to Public Service Co of Oklahoma [Member]
Cook Coal Terminal
Railcar Maintenance		$ 0.8	0.7	0.5
AEP Generating Co To Southwestern Electric Power Co [Member]
Cook Coal Terminal
Railcar Maintenance		4	3.4	3.5
AEP Energy Partners, Inc. to AEP Texas Inc. [Member]
Oklaunion PPA between AEP Texas and AEPEP
Oklaunion Purchase Power Agreement		157	104	64
Indiana Michigan Power Co to AEP Transmission Co [Member]
Joint License Agreement
Joint License Agreement		1.5	2.2	1.4
Kentucky Power Co to AEP Transmission Co [Member]
Joint License Agreement
Joint License Agreement		0.3	0.2	0.2
Ohio Power Co to AEP Transmission Co [Member]
Joint License Agreement
Joint License Agreement		2.2	2.9	2.4
Public Service Co of Oklahoma to AEP Transmission Co [Member]
Joint License Agreement
Joint License Agreement		0.3	0.3	0.3
Wheeling Power Co to AEP Transmission Co [Member]
Joint License Agreement
Joint License Agreement		0.1	0	0
AEP Wind Holdings LLC [Member]
Sempra Renewables LLC PPAs [Abstract]
WindGenerationMWs | MW	724
AEP Generating Co [Member]
Barging, Urea Transloading and Other Services
Expenses from Barging, Urea Transloading and Other Services		14.9	19.9	15.3
AEP Generation Resources [Member]
Barging, Urea Transloading and Other Services
Expenses from Barging, Urea Transloading and Other Services		0	0	0.1
Central Machine Shop
Billings for Services from Central Machine Shop Facility		0.8	1.6	1.2
AEP Transmission Co [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		806.7	598.9	568.1
Sales and Purchases of Property
Related Party Purchases of Property		10.2	18.5	9.1
Charitable Contribution to AEP Foundation [Abstract]
Related Party Charitable Contribuions to AEP Foundation		6.5
AEP Transmission Co [Member] | Direct Sales to East Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
AEP Transmission Co [Member] | Direct Sales to West Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
AEP Transmission Co [Member] | Auction Sales to OPCo [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
AEP Transmission Co [Member] | Direct Sales to AEPEP [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
AEP Transmission Co [Member] | Transmission Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		795.5	591.4	559.6
AEP Transmission Co [Member] | Other Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		11.2	7.5	8.5
Appalachian Power Co [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		205.3	181.4	172
Transmission Service Charges
PJM Net Transmission Service Charges		222.3	128.3	158.2
Barging, Urea Transloading and Other Services
Expenses from Barging, Urea Transloading and Other Services		38.9	35.1	37.2
Sales and Purchases of Property
Related Party Sales of Property		5.5	5.4	3.5
Related Party Purchases of Property		6	0.6	0.9
Charitable Contribution to AEP Foundation [Abstract]
Related Party Charitable Contribuions to AEP Foundation		8.9
Appalachian Power Co [Member] | Direct Sales to East Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		128.6	133.2	130.4
Appalachian Power Co [Member] | Direct Sales to West Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
Appalachian Power Co [Member] | Auction Sales to OPCo [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		11.4	5.8	1
Appalachian Power Co [Member] | Direct Sales to AEPEP [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
Appalachian Power Co [Member] | Transmission Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		58.5	36.4	34.1
Appalachian Power Co [Member] | Other Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		6.8	6	6.5
Indiana Michigan Power Co [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		10.5	22.1	1.8
Cost of Purchased Power from Affiliate		214.9	237.9	223.9
Transmission Service Charges
PJM Net Transmission Service Charges		143.5	91.4	103.8
Central Machine Shop
Billings for Services from Central Machine Shop Facility		2.3	2.4	2.7
Sales and Purchases of Property
Related Party Sales of Property		7.5	8.2	5
Related Party Purchases of Property		0.9	2	3.5
Charitable Contribution to AEP Foundation [Abstract]
Related Party Charitable Contribuions to AEP Foundation		9
Indiana Michigan Power Co [Member] | Auction Purchases From AEPEP [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate		0	0	0
Indiana Michigan Power Co [Member] | Auction Purchases From AEP Energy [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate		0	0	0
Indiana Michigan Power Co [Member] | Auction Purchases from AEPSC [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate		0	0	0
Indiana Michigan Power Co [Member] | Direct Purchases from AEGCo [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate		214.9	237.9	223.9
Indiana Michigan Power Co [Member] | Direct Sales to East Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0.1	0
Indiana Michigan Power Co [Member] | Direct Sales to West Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	3.8
Indiana Michigan Power Co [Member] | Auction Sales to OPCo [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		6.7	7.1	0
Indiana Michigan Power Co [Member] | Direct Sales to AEPEP [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
Indiana Michigan Power Co [Member] | Transmission Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0.7	11.7	(4.4)
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		3.1	3.2	2.4
Kentucky Power Co [Member]
Barging, Urea Transloading and Other Services
Expenses from Barging, Urea Transloading and Other Services		4.8	4.2	5
Central Machine Shop
Billings for Services from Central Machine Shop Facility		1.4	1.7	1.8
Ohio Power Co [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		27.3	21	24.4
Cost of Purchased Power from Affiliate		156	135.3	108.5
Transmission Service Charges
PJM Net Transmission Service Charges		373.4	210.1	248.6
Sales and Purchases of Property
Related Party Sales of Property		7	10.7	2.9
Related Party Purchases of Property		3	2.8	1.6
Charitable Contribution to AEP Foundation [Abstract]
Related Party Charitable Contribuions to AEP Foundation		5.4
Ohio Power Co [Member] | Auction Purchases From AEPEP [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate		64.6	79.7	96.5
Ohio Power Co [Member] | Auction Purchases From AEP Energy [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate		69.9	41	5.5
Ohio Power Co [Member] | Auction Purchases from AEPSC [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate		21.5	14.6	6.5
Ohio Power Co [Member] | Direct Purchases from AEGCo [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate		0	0	0
Ohio Power Co [Member] | Direct Sales to East Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
Ohio Power Co [Member] | Direct Sales to West Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
Ohio Power Co [Member] | Auction Sales to OPCo [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
Ohio Power Co [Member] | Direct Sales to AEPEP [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
Ohio Power Co [Member] | Transmission Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		7.7	3.9	6.2
Ohio Power Co [Member] | Other Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		19.6	17.1	18.2
Public Service Co Of Oklahoma [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		6.1	5.4	4.3
Transmission Service Charges
SPP Net Transmission Service Charges		46.9	65.9	56
Central Machine Shop
Billings for Services from Central Machine Shop Facility		1.1	0.5	1.1
Sales and Purchases of Property
Related Party Sales of Property		0.8	1	1.5
Related Party Purchases of Property		0.5	1.3	0.2
Charitable Contribution to AEP Foundation [Abstract]
Related Party Charitable Contribuions to AEP Foundation		3.4
Public Service Co Of Oklahoma [Member] | Direct Sales to East Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
Public Service Co Of Oklahoma [Member] | Direct Sales to West Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
Public Service Co Of Oklahoma [Member] | Auction Sales to OPCo [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
Public Service Co Of Oklahoma [Member] | Direct Sales to AEPEP [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
Public Service Co Of Oklahoma [Member] | Transmission Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		1.3	0.9	0
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		4.8	4.5	4.3
Southwestern Electric Power Co [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		36.9	35.1	25.9
Revenue from Related Parties, Net		4.9	28.4
Transmission Service Charges
SPP Net Transmission Service Charges		20.1	10.5	6.6
Central Machine Shop
Billings for Services from Central Machine Shop Facility		1.1	0.7	0.8
Sales and Purchases of Property
Related Party Sales of Property		0.2	0.8	0.5
Related Party Purchases of Property		0.7	0.8	0.4
Charitable Contribution to AEP Foundation [Abstract]
Related Party Charitable Contribuions to AEP Foundation		5.5
Southwestern Electric Power Co [Member] | Direct Sales to East Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
Southwestern Electric Power Co [Member] | Direct Sales to West Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
Southwestern Electric Power Co [Member] | Auction Sales to OPCo [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
Southwestern Electric Power Co [Member] | Direct Sales to AEPEP [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		(0.1)	0	(0.2)
Southwestern Electric Power Co [Member] | Transmission Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		3.6	26.9	24.2
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		1.4	1.5	1.9
Wheeling Power Co [Member] [Domain]
Barging, Urea Transloading and Other Services
Expenses from Barging, Urea Transloading and Other Services		4.8	4.2	5
AEP Texas Inc. [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		160.5	105.2	65.7
ERCOT Transmission Service Charges
Billings from ETT for ERCOT Wholesale Transmission Services		27	27	30
Oklaunion PPA between AEP Texas and AEPEP
Oklaunion Purchase Power Agreement		0	22.1
Sales and Purchases of Property
Related Party Sales of Property		0.9	0.3	0.2
Related Party Purchases of Property		$ 0.3	0.1	0.4
Related Party Transactions (Textuals)
Jointly Owned Utility Plant, Proportionate Ownership Share		54.69%
Charitable Contribution to AEP Foundation [Abstract]
Related Party Charitable Contribuions to AEP Foundation		$ 6.2
AEP Texas Inc. [Member] | Direct Sales to East Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
AEP Texas Inc. [Member] | Direct Sales to West Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
AEP Texas Inc. [Member] | Auction Sales to OPCo [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
AEP Texas Inc. [Member] | Direct Sales to AEPEP [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		157.2	103.6	63.6
AEP Texas Inc. [Member] | Transmission Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		0	0	0
AEP Texas Inc. [Member] | Other Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues		$ 3.3	$ 1.6	$ 2.1

Variable Interest Entities (Det

Variable Interest Entities (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)MW	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Variable Interest Entities (Textuals)
Securitization Bonds	$ 1,025.1	$ 1,111.4
Securitized Assets	858.1	920.6
Redeemable Noncontrolling Interest	65.7	69.4
Equity Method Investments	1,356.6	846.2
Equity Method Investment Income	$ 72.1	73.1	$ 82.4
Trent and Desert Sky Wind Farms [Member]
Variable Interest Entities (Textuals)
Non-Affiliate Interest	20.10%
AEP Ownership in LLCs	79.90%
Desert Sky and Trent PPA Period	12 years
Redeemable Noncontrolling Interest	$ 66	69
Trent and Desert Sky Wind Farms [Member] | Current Assets [Member]
ASSETS
Assets	7.8	6.8
Trent and Desert Sky Wind Farms [Member] | Net Property Plant And Equipment [Member]
ASSETS
Assets	330.6	348.5
Trent and Desert Sky Wind Farms [Member] | Net Property Plant And Equipment [Member] | Non-Affiliate Contribution [Member]
ASSETS
Assets	84
Trent and Desert Sky Wind Farms [Member] | Other Noncurrent Assets [Member]
ASSETS
Assets	10.1	0
Trent and Desert Sky Wind Farms [Member] | Total Assets [Member]
ASSETS
Assets	348.5	355.3
Trent and Desert Sky Wind Farms [Member] | Current Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	5.5	8.7
Trent and Desert Sky Wind Farms [Member] | Noncurrent Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	15.8	6.2
Trent and Desert Sky Wind Farms [Member] | Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	327.2	340.4
Trent and Desert Sky Wind Farms [Member] | Total Liabilities And Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	348.5	355.3
Apple Blossom and Black Oak [Member]
Variable Interest Entities (Textuals)
Noncontrolling Interest in Variable Interest Entity	128
HLBV Income for Noncontrolling Interests	6
Apple Blossom and Black Oak [Member] | Current Assets [Member]
ASSETS
Assets	10.1
Apple Blossom and Black Oak [Member] | Net Property Plant And Equipment [Member]
ASSETS
Assets	231.4
Apple Blossom and Black Oak [Member] | Other Noncurrent Assets [Member]
ASSETS
Assets	13.1
Apple Blossom and Black Oak [Member] | Total Assets [Member]
ASSETS
Assets	254.6
Apple Blossom and Black Oak [Member] | Current Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	5.4
Apple Blossom and Black Oak [Member] | Noncurrent Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	4.7
Apple Blossom and Black Oak [Member] | Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	244.5
Apple Blossom and Black Oak [Member] | Total Liabilities And Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	254.6
Santa Rita East [Member]
Variable Interest Entities (Textuals)
Noncontrolling Interest in Variable Interest Entity	$ 118
Percentage of an Asset Acquired	75.00%
Production Tax Credits	$ 10
Santa Rita East [Member] | Total Generation MWs [Member]
Variable Interest Entities (Textuals)
WindGenerationMWs | MW	302
Santa Rita East [Member] | Long-term PPA MWs [Member]
Variable Interest Entities (Textuals)
WindGenerationMWs | MW	260
Santa Rita East [Member] | Sold at Wholesale MWs [Member]
Variable Interest Entities (Textuals)
WindGenerationMWs | MW	42
Santa Rita East [Member] | Current Assets [Member]
ASSETS
Assets	$ 17.7
Santa Rita East [Member] | Net Property Plant And Equipment [Member]
ASSETS
Assets	465.2
Santa Rita East [Member] | Other Noncurrent Assets [Member]
ASSETS
Assets	0.3
Santa Rita East [Member] | Total Assets [Member]
ASSETS
Assets	483.2
Santa Rita East [Member] | Current Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	3.9
Santa Rita East [Member] | Noncurrent Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	7.5
Santa Rita East [Member] | Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	471.8
Santa Rita East [Member] | Total Liabilities And Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	483.2
Protected Cell Of Energy Insurance Services, Inc. [Member]
Variable Interest Entities (Textuals)
Insurance Premium Expense to Protected Cell	34	34	29
Protected Cell Of Energy Insurance Services, Inc. [Member] | Current Assets [Member]
ASSETS
Assets	194.6	177.8
Protected Cell Of Energy Insurance Services, Inc. [Member] | Net Property Plant And Equipment [Member]
ASSETS
Assets	0	0
Protected Cell Of Energy Insurance Services, Inc. [Member] | Other Noncurrent Assets [Member]
ASSETS
Assets	0	0.1
Protected Cell Of Energy Insurance Services, Inc. [Member] | Total Assets [Member]
ASSETS
Assets	194.6	177.9
Protected Cell Of Energy Insurance Services, Inc. [Member] | Current Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	40.7	38.6
Protected Cell Of Energy Insurance Services, Inc. [Member] | Noncurrent Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	78	85.3
Protected Cell Of Energy Insurance Services, Inc. [Member] | Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	75.9	54
Protected Cell Of Energy Insurance Services, Inc. [Member] | Total Liabilities And Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	$ 194.6	177.9
Transource Energy [Member]
Variable Interest Entities (Textuals)
Debt-to-Total Capitalization Maximum	67.50%
Proceeds from Partnership Contribution	$ 0	4	5
Transource Energy [Member] | Current Assets [Member]
ASSETS
Assets	25.8	25.7
Transource Energy [Member] | Net Property Plant And Equipment [Member]
ASSETS
Assets	424.1	380.3
Transource Energy [Member] | Other Noncurrent Assets [Member]
ASSETS
Assets	3.2	1.9
Transource Energy [Member] | Total Assets [Member]
ASSETS
Assets	453.1	407.9
Transource Energy [Member] | Current Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	192.4	19.9
Transource Energy [Member] | Noncurrent Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	4.8	160.3
Transource Energy [Member] | Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	255.9	227.7
Transource Energy [Member] | Total Liabilities And Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	$ 453.1	407.9
AEP Credit, Inc. [Member]
Variable Interest Entities (Textuals)
Minimum Percentage of Equity AEP Provides	5.00%
Percentage Of Short Term Borrowing Needs In Excess Of Third Party Financings	20.00%
AEP Credit, Inc. [Member] | Current Assets [Member]
ASSETS
Assets	$ 842.8	974.2
AEP Credit, Inc. [Member] | Net Property Plant And Equipment [Member]
ASSETS
Assets	0	0
AEP Credit, Inc. [Member] | Other Noncurrent Assets [Member]
ASSETS
Assets	7.1	6.3
AEP Credit, Inc. [Member] | Total Assets [Member]
ASSETS
Assets	849.9	980.5
AEP Credit, Inc. [Member] | Current Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	805.2	923.5
AEP Credit, Inc. [Member] | Noncurrent Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	0.9	0.8
AEP Credit, Inc. [Member] | Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	43.8	56.2
AEP Credit, Inc. [Member] | Total Liabilities And Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	$ 849.9	980.5
PATH West Virginia Transmission Co, LLC [Member]
Variable Interest Entities (Textuals)
Percentage of Ownership of Allegheny Series by a Nonaffiliated Company	100.00%
Percentage of Debt in PATH's Stipulation Agreement	50.00%
Percentage of Equity Capital Structure in PATH's Stipulation Agreement	50.00%
Percentage of Cost of Long Term Debt for PATH's Stipulation Agreement	4.70%
Percentage of PATH WV's Lowered Authorized ROE	8.11%
Percentage of PATH WV's Previously Authorized ROE	10.40%
PATH-WV Refund	$ 11
Accumulated Provisions For Rate Refunds	1
PATH West Virginia Transmission Co, LLC [Member] | Capital Contribution From Parent [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet	18.8	18.8
Maximum Exposure	18.8	18.8
PATH West Virginia Transmission Co, LLC [Member] | Retained Earnings [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet	(1.7)	(1.4)
Maximum Exposure	(1.7)	(1.4)
PATH West Virginia Transmission Co, LLC [Member] | Total Investment [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet	17.1	17.4
Maximum Exposure	$ 17.1	17.4
Ohio Valley Electric Corporation [Member]
Variable Interest Entities (Textuals)
AEP's Ownership In OVEC	43.47%
Approximate OVEC Generating Capacity (MWs) | MW	2,400
Intercompany Power Agreement End Date	2040
Outstanding Indebtedness	$ 1,400	1,400
Ohio Valley Electric Corporation [Member] | Capital Contribution From Parent [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet	4.4	4.4
Maximum Exposure	4.4	4.4
Ohio Valley Electric Corporation [Member] | AEP's Ratio of OVEC Debt [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet	0	0
Maximum Exposure	588.9	604.1
Ohio Valley Electric Corporation [Member] | Total Investment [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet	4.4	4.4
Maximum Exposure	593.3	608.5
Dolet Hills Lignite Co, LLC [Member]
Variable Interest Entities (Textuals)
Equity Method Investment Income	$ 3	2.7	0
Parent Company [Member] | Ohio Valley Electric Corporation [Member]
Variable Interest Entities (Textuals)
AEP's Ownership In OVEC	39.17%
Great Plains Energy Inc. [Member] | Transource Energy [Member]
Variable Interest Entities (Textuals)
Equity and Voting Ownership Percentage	13.50%
Cleco Power, LLC [Member]
Variable Interest Entities (Textuals)
Percentage of VIE Sales of Lignite Produced	50.00%
AEP Transmission Co [Member] | Billings from AEP Service Corporation [Member]
Variable Interest Entities (Textuals)
Billings from VIE	$ 242.3	220.4	188.9
AEP Transmission Co [Member] | Carrying Amount in AEP Service Corporation's Accounts Payable [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet	33.4	24.6
Maximum Exposure	33.4	24.6
Appalachian Power Co [Member]
Variable Interest Entities (Textuals)
Securitization Bonds	248.3	272.3
Securitized Assets	234.7	258.7
Amount Of Power Purchased From OVEC	104.5	100.4	101
Appalachian Power Co [Member] | Billings from AEP Service Corporation [Member]
Variable Interest Entities (Textuals)
Billings from VIE	308.3	295.6	268.8
Appalachian Power Co [Member] | Carrying Amount in AEP Service Corporation's Accounts Payable [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet	44.1	32.2
Maximum Exposure	44.1	32.2
Appalachian Power Co [Member] | Appalachian Consumer Rate Relief Funding [Member]
Variable Interest Entities (Textuals)
Securitization Bonds	223	272
Securitized Assets	235	259
Appalachian Power Co [Member] | Appalachian Consumer Rate Relief Funding [Member] | Current Assets [Member]
ASSETS
Assets	21.5	24.8
Appalachian Power Co [Member] | Appalachian Consumer Rate Relief Funding [Member] | Net Property Plant And Equipment [Member]
ASSETS
Assets	0	0
Appalachian Power Co [Member] | Appalachian Consumer Rate Relief Funding [Member] | Other Noncurrent Assets [Member]
ASSETS
Assets	237.5	261.8
Variable Interest Entities (Textuals)
Intercompany Item Eliminated in Consolidation	3	3
Appalachian Power Co [Member] | Appalachian Consumer Rate Relief Funding [Member] | Total Assets [Member]
ASSETS
Assets	259	286.6
Appalachian Power Co [Member] | Appalachian Consumer Rate Relief Funding [Member] | Current Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	28.3	28
Appalachian Power Co [Member] | Appalachian Consumer Rate Relief Funding [Member] | Noncurrent Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	228.8	256.7
Appalachian Power Co [Member] | Appalachian Consumer Rate Relief Funding [Member] | Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	1.9	1.9
Appalachian Power Co [Member] | Appalachian Consumer Rate Relief Funding [Member] | Total Liabilities And Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	$ 259	286.6
Appalachian Power Co [Member] | Ohio Valley Electric Corporation [Member]
Variable Interest Entities (Textuals)
Power Participation Ratio	15.69%
Outstanding Indebtedness	$ 213	218
Indiana Michigan Power Co [Member]
Variable Interest Entities (Textuals)
Amount Of Power Purchased From OVEC	$ 52.3	50.2	50.5
Indiana Michigan Power Co [Member] | Rockport Generating Plant (Unit No. 1) [Member]
Variable Interest Entities (Textuals)
Jointly Owned Utility Plant, Proportionate Ownership Share	50.00%
Indiana Michigan Power Co [Member] | DCC Fuel [Member]
Variable Interest Entities (Textuals)
Payments Made by I&M to DCC Fuel	$ 95	113	136
Indiana Michigan Power Co [Member] | DCC Fuel [Member] | Current Assets [Member]
ASSETS
Assets	86.5	77.6
Indiana Michigan Power Co [Member] | DCC Fuel [Member] | Net Property Plant And Equipment [Member]
ASSETS
Assets	156.8	122.3
Indiana Michigan Power Co [Member] | DCC Fuel [Member] | Other Noncurrent Assets [Member]
ASSETS
Assets	82.5	58.4
Indiana Michigan Power Co [Member] | DCC Fuel [Member] | Total Assets [Member]
ASSETS
Assets	325.8	258.3
Indiana Michigan Power Co [Member] | DCC Fuel [Member] | Current Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	86.4	77.1
Indiana Michigan Power Co [Member] | DCC Fuel [Member] | Noncurrent Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	239.4	181.2
Indiana Michigan Power Co [Member] | DCC Fuel [Member] | Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	0	0
Indiana Michigan Power Co [Member] | DCC Fuel [Member] | Total Liabilities And Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	325.8	258.3
Indiana Michigan Power Co [Member] | Billings from AEP Service Corporation [Member]
Variable Interest Entities (Textuals)
Billings from VIE	184.8	173.5	176
Indiana Michigan Power Co [Member] | Billings from AEP Generating Company [Member]
Variable Interest Entities (Textuals)
Billings from VIE	215	238	224
Indiana Michigan Power Co [Member] | Carrying Amount in AEP Service Corporation's Accounts Payable [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet	28.6	23.8
Maximum Exposure	28.6	23.8
Indiana Michigan Power Co [Member] | Carrying Amount in AEP Generating Company's Accounts Payable [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet	$ 10	20
Indiana Michigan Power Co [Member] | Ohio Valley Electric Corporation [Member]
Variable Interest Entities (Textuals)
Power Participation Ratio	7.85%
Outstanding Indebtedness	$ 106	109
Ohio Power Co [Member]
Variable Interest Entities (Textuals)
Securitization Bonds	0	47.8
Securitized Assets	0	12.9
Amount Of Power Purchased From OVEC	132.7	127.5	128.2
Ohio Power Co [Member] | Billings from AEP Service Corporation [Member]
Variable Interest Entities (Textuals)
Billings from VIE	230.4	214.9	195.7
Ohio Power Co [Member] | Carrying Amount in AEP Service Corporation's Accounts Payable [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet	33.2	23.9
Maximum Exposure	33.2	23.9
Ohio Power Co [Member] | Ohio Phase-In-Recovery Funding [Member]
Variable Interest Entities (Textuals)
Securitization Bonds	0	48
Securitized Assets	0	13
Ohio Power Co [Member] | Ohio Phase-In-Recovery Funding [Member] | Current Assets [Member]
ASSETS
Assets	0	29.5
Ohio Power Co [Member] | Ohio Phase-In-Recovery Funding [Member] | Net Property Plant And Equipment [Member]
ASSETS
Assets	0	0
Ohio Power Co [Member] | Ohio Phase-In-Recovery Funding [Member] | Other Noncurrent Assets [Member]
ASSETS
Assets	0	24.2
Variable Interest Entities (Textuals)
Intercompany Item Eliminated in Consolidation		11
Ohio Power Co [Member] | Ohio Phase-In-Recovery Funding [Member] | Total Assets [Member]
ASSETS
Assets	0	53.7
Ohio Power Co [Member] | Ohio Phase-In-Recovery Funding [Member] | Current Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	0	48.5
Ohio Power Co [Member] | Ohio Phase-In-Recovery Funding [Member] | Noncurrent Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	0	3.9
Ohio Power Co [Member] | Ohio Phase-In-Recovery Funding [Member] | Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	0	1.3
Ohio Power Co [Member] | Ohio Phase-In-Recovery Funding [Member] | Total Liabilities And Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	$ 0	53.7
Ohio Power Co [Member] | Ohio Valley Electric Corporation [Member]
Variable Interest Entities (Textuals)
AEP's Ownership In OVEC	4.30%
Power Participation Ratio	19.93%
Outstanding Indebtedness	$ 270	277
Public Service Co Of Oklahoma [Member] | Billings from AEP Service Corporation [Member]
Variable Interest Entities (Textuals)
Billings from VIE	125.7	121.5	114.7
Public Service Co Of Oklahoma [Member] | Carrying Amount in AEP Service Corporation's Accounts Payable [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet	18.1	13.2
Maximum Exposure	18.1	13.2
Southwestern Electric Power Co [Member]
Variable Interest Entities (Textuals)
Equity Method Investment Income	3	2.7	(3.8)
Southwestern Electric Power Co [Member] | Sabine Mining Co [Member]
Estimated Final Cost Mine Reclamation	107
Amount Collected Through Rider For Final Mine Closure And Reclamation Costs	78
Amount Collected, Rider Mine Close ARO Noncurrent	5
Amount Collected, Rider Mine Close Other Assets Noncurrent	83
Variable Interest Entities (Textuals)
Billings from VIE	110	152	137
Guarantees Of Mine Reclamation Amount	155
Southwestern Electric Power Co [Member] | Sabine Mining Co [Member] | Current Assets [Member]
ASSETS
Assets	80	70
Southwestern Electric Power Co [Member] | Sabine Mining Co [Member] | Net Property Plant And Equipment [Member]
ASSETS
Assets	111.6	106.9
Southwestern Electric Power Co [Member] | Sabine Mining Co [Member] | Other Noncurrent Assets [Member]
ASSETS
Assets	93.2	98.5
Southwestern Electric Power Co [Member] | Sabine Mining Co [Member] | Total Assets [Member]
ASSETS
Assets	284.8	275.4
Southwestern Electric Power Co [Member] | Sabine Mining Co [Member] | Current Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	50.6	31.1
Southwestern Electric Power Co [Member] | Sabine Mining Co [Member] | Noncurrent Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	233.6	244
Southwestern Electric Power Co [Member] | Sabine Mining Co [Member] | Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	0.6	0.3
Southwestern Electric Power Co [Member] | Sabine Mining Co [Member] | Total Liabilities And Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	284.8	275.4
Southwestern Electric Power Co [Member] | Billings from AEP Service Corporation [Member]
Variable Interest Entities (Textuals)
Billings from VIE	169.5	164.4	150.7
Southwestern Electric Power Co [Member] | Carrying Amount in AEP Service Corporation's Accounts Payable [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet	23.4	18.4
Maximum Exposure	23.4	18.4
Southwestern Electric Power Co [Member] | Dolet Hills Lignite Co, LLC [Member]
Variable Interest Entities (Textuals)
Billings from VIE	$ 55	58	61
Percentage of VIE Sales of Lignite Produced	50.00%
Percentage of DHLCs Debt Guaranteed by Each SWEPCo and CLECO	50.00%
Percentage of Management Fee Received by SWEPCo from DHLC	100.00%
Equity Method Investment Income	$ 3	2.7	0
Southwestern Electric Power Co [Member] | Dolet Hills Lignite Co, LLC [Member] | Capital Contribution From Parent [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet	7.6	7.6
Maximum Exposure	7.6	7.6
Southwestern Electric Power Co [Member] | Dolet Hills Lignite Co, LLC [Member] | Retained Earnings [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet	17.5	14.5
Maximum Exposure	17.5	14.5
Southwestern Electric Power Co [Member] | Dolet Hills Lignite Co, LLC [Member] | SWEPCo's Share of Obligations [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet	0	0
Maximum Exposure	130	167.6
Southwestern Electric Power Co [Member] | Dolet Hills Lignite Co, LLC [Member] | Total Investment [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet	25.1	22.1
Maximum Exposure	$ 155.1	189.7
AEP Generating Co [Member] | Rockport Generating Plant (Unit No. 1) [Member]
Variable Interest Entities (Textuals)
Jointly Owned Utility Plant, Proportionate Ownership Share	50.00%
AEP Generating Co [Member] | Rockport Generating Plant (Unit No. 2) [Member]
Variable Interest Entities (Textuals)
Percentage Interest in Lease	50.00%
Transource Energy [Member]
Variable Interest Entities (Textuals)
Equity and Voting Ownership Percentage	86.50%
AEP Texas Inc. [Member]
Variable Interest Entities (Textuals)
Securitization Bonds	$ 776.8	791.2
Securitized Assets	$ 623.4	649.1
Jointly Owned Utility Plant, Proportionate Ownership Share	54.69%
AEP Texas Inc. [Member] | AEP Texas Central Transition Funding Co [Member]
Variable Interest Entities (Textuals)
Securitization Bonds	$ 541	791
Securitized Assets	389	637
AEP Texas Inc. [Member] | AEP Texas Central Transition Funding Co [Member] | Current Assets [Member]
ASSETS
Assets	187	192.8
AEP Texas Inc. [Member] | AEP Texas Central Transition Funding Co [Member] | Net Property Plant And Equipment [Member]
ASSETS
Assets	0	0
AEP Texas Inc. [Member] | AEP Texas Central Transition Funding Co [Member] | Other Noncurrent Assets [Member]
ASSETS
Assets	428.1	683.5
Variable Interest Entities (Textuals)
Intercompany Item Eliminated in Consolidation	39	47
AEP Texas Inc. [Member] | AEP Texas Central Transition Funding Co [Member] | Total Assets [Member]
ASSETS
Assets	615.1	876.3
AEP Texas Inc. [Member] | AEP Texas Central Transition Funding Co [Member] | Current Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	280.2	271.9
AEP Texas Inc. [Member] | AEP Texas Central Transition Funding Co [Member] | Noncurrent Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	316.3	586.1
AEP Texas Inc. [Member] | AEP Texas Central Transition Funding Co [Member] | Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	18.6	18.3
AEP Texas Inc. [Member] | AEP Texas Central Transition Funding Co [Member] | Total Liabilities And Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	615.1	876.3
AEP Texas Inc. [Member] | Restoration Funding [Member]
Variable Interest Entities (Textuals)
Securitization Bonds	235
Securitized Assets	232
AEP Texas Inc. [Member] | Restoration Funding [Member] | Current Assets [Member]
ASSETS
Assets	9.4
AEP Texas Inc. [Member] | Restoration Funding [Member] | Net Property Plant And Equipment [Member]
ASSETS
Assets	0
AEP Texas Inc. [Member] | Restoration Funding [Member] | Other Noncurrent Assets [Member]
ASSETS
Assets	234.4
Variable Interest Entities (Textuals)
Intercompany Item Eliminated in Consolidation	1
AEP Texas Inc. [Member] | Restoration Funding [Member] | Total Assets [Member]
ASSETS
Assets	243.8
AEP Texas Inc. [Member] | Restoration Funding [Member] | Current Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	16.3
AEP Texas Inc. [Member] | Restoration Funding [Member] | Noncurrent Liabilities [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	226.3
AEP Texas Inc. [Member] | Restoration Funding [Member] | Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	1.2
AEP Texas Inc. [Member] | Restoration Funding [Member] | Total Liabilities And Equity [Member]
LIABILITIES AND EQUITY
Liabilities and Equity	243.8
AEP Texas Inc. [Member] | Billings from AEP Service Corporation [Member]
Variable Interest Entities (Textuals)
Billings from VIE	206.6	184.3	152.6
AEP Texas Inc. [Member] | Carrying Amount in AEP Service Corporation's Accounts Payable [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet	32.4	22.3
Maximum Exposure	$ 32.4	22.3
JV Wind Farms [Member]
Variable Interest Entities (Textuals)
Equity Method Investment, Ownership Percentage	50.00%
Production Tax Credits	$ 27
Equity Method Investments	394
Historical Investment Balance	420
Historical Investment Basis Difference	(18)
Equity Method Investment Income	$ 4
Berkshire Hathaway [Member]
Variable Interest Entities (Textuals)
Equity Method Investment, Ownership Percentage	50.00%
AEP Transmission Holdco [Member]
Variable Interest Entities (Textuals)
Equity Method Investment, Ownership Percentage	49.50%
AEP Transmission Partner [Member]
Variable Interest Entities (Textuals)
Equity Method Investment, Ownership Percentage	0.50%
BP Wind Energy [Member]
Variable Interest Entities (Textuals)
Equity Method Investment, Ownership Percentage	50.00%
ETT [Member]
Variable Interest Entities (Textuals)
Equity Method Investment, Ownership Percentage	50.00%
Equity Method Investments	$ 695	666
Equity Method Investment Income	$ 66	$ 62	$ 82

Property, Plant and Equipment_3

Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation	$ 22,762.4	$ 21,699.9
Property, Plant and Equipment, Transmission	24,808.6	21,531
Property, Plant and Equipment, Distribution	22,443.4	21,195.4
Property, Plant and Equipment, Other	4,811.5	4,265
Property, Plant and Equipment, Construction Work in Progress	4,319.8	4,393.9
Accumulated Depreciation	19,007.6	17,986.1
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	60,138.1	55,099.1
Asset Retirement Obligations (ARO)
Beginning Balance	2,355.5	2,005.7
Accretion Expense	102.5	93.7
Liabilities Incurred	12	0.8
Liabilities Settled	(118.1)	(87)
Revisions in Cash Flow Estimates	67	342.3
Ending Balance	2,418.9	2,355.5	$ 2,005.7
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction	168.4	132.5	93.7
Allowance for Borrowed Funds Used During Construction	88.7	73.6	48.6
Jointly-owned Electric Facilities
Utility Plant in Service	3,019.3	3,015.9
Construction Work in Progress	19.1	24.6
Accumulated Depreciation	1,051.9	984.2
Asset Impairments and Other Related Charges	156.4	70.6	87.1
Property, Plant and Equipment (Textuals)
Asset Retirement Obligations (ARO) Liability for Nuclear Decommissioning of the Cook Plant	1,730	1,660
Fair Value of Legally Restricted Assets	2,650	2,160
AEP Texas Inc. [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation	351.7	352.1
Property, Plant and Equipment, Transmission	4,466.5	3,683.6
Property, Plant and Equipment, Distribution	4,215.2	4,043.2
Property, Plant and Equipment, Other	805.9	727.9
Property, Plant and Equipment, Construction Work in Progress	763.9	836.2
Accumulated Depreciation	1,758.1	1,651.2
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	8,845.1	7,991.8
Asset Retirement Obligations (ARO)
Beginning Balance	27.9	26.7
Accretion Expense	1.3	1.2
Liabilities Incurred	0	0
Liabilities Settled	(0.2)	(0.1)
Revisions in Cash Flow Estimates	0.1	0.1
Ending Balance	29.1	27.9	26.7
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction	15.2	20	6.8
Allowance for Borrowed Funds Used During Construction	$ 20	18.4	6.8
Jointly-owned Electric Facilities
Percent of Ownership	54.69%
Asset Impairments and Other Related Charges	$ 32.5	0	0
AEP Transmission Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Transmission	8,137.9	6,515.8
Property, Plant and Equipment, Other	269.6	174
Property, Plant and Equipment, Construction Work in Progress	1,485.7	1,578.3
Accumulated Depreciation	402.3	271.9
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	9,490.9	7,996.2
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction	84.3	70.6	49
Allowance for Borrowed Funds Used During Construction	32.2	26.1	20.2
Appalachian Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation	6,563.7	6,509.6
Property, Plant and Equipment, Transmission	3,584.1	3,317.7
Property, Plant and Equipment, Distribution	4,201.7	3,989.4
Property, Plant and Equipment, Other	571.3	485.8
Property, Plant and Equipment, Construction Work in Progress	593.4	490.2
Accumulated Depreciation	4,432.3	4,124.4
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	11,081.9	10,668.3
Asset Retirement Obligations (ARO)
Beginning Balance	116.1	125
Accretion Expense	5.9	6.6
Liabilities Incurred	0	0
Liabilities Settled	(17.6)	(17.3)
Revisions in Cash Flow Estimates	6.7	1.8
Ending Balance	111.1	116.1	125
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction	16.6	13.2	9.2
Allowance for Borrowed Funds Used During Construction	9.3	8.4	5.3
Jointly-owned Electric Facilities
Asset Impairments and Other Related Charges	92.9	0	0
Indiana Michigan Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation	5,099.7	4,887.2
Property, Plant and Equipment, Transmission	1,641.8	1,576.8
Property, Plant and Equipment, Distribution	2,437.6	2,249.7
Property, Plant and Equipment, Other	632.6	583.8
Property, Plant and Equipment, Construction Work in Progress	382.3	465.3
Accumulated Depreciation	3,294.3	3,151.6
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	6,899.7	6,611.2
Asset Retirement Obligations (ARO)
Beginning Balance	1,681.3	1,321.8
Accretion Expense	67.4	58.7
Liabilities Incurred	0	0
Liabilities Settled	(0.2)	(0.2)
Revisions in Cash Flow Estimates	0.1	301
Ending Balance	1,748.6	1,681.3	1,321.8
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction	19.4	11.9	11.1
Allowance for Borrowed Funds Used During Construction	8.9	7.4	6.7
Property, Plant and Equipment (Textuals)
Asset Retirement Obligations (ARO) Liability for Nuclear Decommissioning of the Cook Plant	1,730	1,660
Fair Value of Legally Restricted Assets	2,650	2,160
Ohio Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Transmission	2,686.3	2,544.3
Property, Plant and Equipment, Distribution	5,323.5	4,942.3
Property, Plant and Equipment, Other	765.8	574.8
Property, Plant and Equipment, Construction Work in Progress	394.4	432.1
Accumulated Depreciation	2,263	2,218.6
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	6,907	6,274.9
Asset Retirement Obligations (ARO)
Beginning Balance	1.8	1.7
Accretion Expense	0.1	0.1
Liabilities Incurred	0	0
Liabilities Settled	(0.3)	0
Revisions in Cash Flow Estimates	0.2	0
Ending Balance	1.8	1.8	1.7
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction	18.2	9.8	6.4
Allowance for Borrowed Funds Used During Construction	6.7	5.8	3.8
Public Service Co Of Oklahoma [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation	1,574.6	1,577
Property, Plant and Equipment, Transmission	948.5	892.3
Property, Plant and Equipment, Distribution	2,684.8	2,572.8
Property, Plant and Equipment, Other	342.1	303.5
Property, Plant and Equipment, Construction Work in Progress	133.4	94
Accumulated Depreciation	1,580.1	1,472.9
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	4,103.3	3,966.7
Asset Retirement Obligations (ARO)
Beginning Balance	46.9	54
Accretion Expense	3.1	3.2
Liabilities Incurred	0	0
Liabilities Settled	(0.4)	(0.4)
Revisions in Cash Flow Estimates	2.6	(9.9)
Ending Balance	52.2	46.9	54
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction	2.7	0.4	0.5
Allowance for Borrowed Funds Used During Construction	1.9	0.9	1.1
Southwestern Electric Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation	4,691.4	4,672.6
Property, Plant and Equipment, Transmission	2,056.5	1,866.9
Property, Plant and Equipment, Distribution	2,270.7	2,178.6
Property, Plant and Equipment, Other	733.4	762.7
Property, Plant and Equipment, Construction Work in Progress	216.9	199.3
Accumulated Depreciation	2,873.7	2,808.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	7,095.2	6,871.8
Asset Retirement Obligations (ARO)
Beginning Balance	206.8	169.2
Accretion Expense	10.3	9.1
Liabilities Incurred	0	0.2
Liabilities Settled	(11.8)	(11.7)
Revisions in Cash Flow Estimates	6.9	40
Ending Balance	212.2	206.8	169.2
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction	6.8	6	2.4
Allowance for Borrowed Funds Used During Construction	4	4.8	2.1
Jointly-owned Electric Facilities
Utility Plant in Service	2,912.7	2,893.1
Construction Work in Progress	19	24.4
Accumulated Depreciation	960.2	914
Asset Impairments and Other Related Charges	$ 0	$ 0	$ 33.6
Conesville Generating Station (Unit No. 4) [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership	83.50%	83.50%		43.50%
Utility Plant in Service	$ 0	$ 16.4
Construction Work in Progress	0	0.2
Accumulated Depreciation	$ 0	$ 2.4
J.M. Stuart Generating Station [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership				26.00%
Wm. H. Zimmer Generating Station [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership				25.40%
Dolet Hills Generating Station (Unit No. 1) [Member] | Public Utilities, Inventory, Lignite [Member]
Jointly-owned Electric Facilities
Percent of Ownership	40.20%	40.20%
Utility Plant in Service	$ 337.3	$ 336.2
Construction Work in Progress	6.2	5.1
Accumulated Depreciation	$ 216.5	$ 209.6
Dolet Hills Generating Station (Unit No. 1) [Member] | Southwestern Electric Power Co [Member] | Public Utilities, Inventory, Lignite [Member]
Jointly-owned Electric Facilities
Percent of Ownership	40.20%	40.20%
Utility Plant in Service	$ 337.3	$ 336.2
Construction Work in Progress	6.2	5.1
Accumulated Depreciation	$ 216.5	$ 209.6
Flint Creek Generating Station (Unit No. 1) [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership	50.00%	50.00%
Utility Plant in Service	$ 374.3	$ 375.1
Construction Work in Progress	3.4	1.6
Accumulated Depreciation	$ 101.1	$ 88.9
Flint Creek Generating Station (Unit No. 1) [Member] | Southwestern Electric Power Co [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership	50.00%	50.00%
Utility Plant in Service	$ 374.3	$ 375.1
Construction Work in Progress	3.4	1.6
Accumulated Depreciation	$ 101.1	$ 88.9
Pirkey Generating Station (Unit No. 1) [Member] | Public Utilities, Inventory, Lignite [Member]
Jointly-owned Electric Facilities
Percent of Ownership	85.90%	85.90%
Utility Plant in Service	$ 607.8	$ 591.3
Construction Work in Progress	7.7	16.6
Accumulated Depreciation	$ 416.8	$ 418
Pirkey Generating Station (Unit No. 1) [Member] | Southwestern Electric Power Co [Member] | Public Utilities, Inventory, Lignite [Member]
Jointly-owned Electric Facilities
Percent of Ownership	85.90%	85.90%
Utility Plant in Service	$ 607.8	$ 591.3
Construction Work in Progress	7.7	16.6
Accumulated Depreciation	$ 416.8	$ 418
Oklaunion Generating Station (Unit No. 1) [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership	70.30%	70.30%
Utility Plant in Service	$ 106.6	$ 106.4
Construction Work in Progress	0.1	0
Accumulated Depreciation	$ 91.7	$ 67.8
Oklaunion Generating Station (Unit No. 1) [Member] | AEP Texas Inc. [Member]
Jointly-owned Electric Facilities
Percent of Ownership	54.70%
Oklaunion Generating Station (Unit No. 1) [Member] | AEP Texas Inc. [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership	54.70%	54.70%		54.70%
Utility Plant in Service	$ 351.7	$ 352.1
Construction Work in Progress	0	0.2
Accumulated Depreciation	$ 291.9	$ 218.6
Oklaunion Generating Station (Unit No. 1) [Member] | Public Service Co Of Oklahoma [Member]
Jointly-owned Electric Facilities
Percent of Ownership	15.60%
Oklaunion Generating Station (Unit No. 1) [Member] | Public Service Co Of Oklahoma [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership	15.60%	15.60%
Utility Plant in Service	$ 106.6	$ 106.4
Construction Work in Progress	0.1	0
Accumulated Depreciation	$ 91.7	$ 67.8
Turk Generating Plant [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership	73.30%	73.30%
Utility Plant in Service	$ 1,593.3	$ 1,590.5
Construction Work in Progress	1.7	1.1
Accumulated Depreciation	$ 225.8	$ 197.5
Turk Generating Plant [Member] | Southwestern Electric Power Co [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership	73.30%	73.30%
Utility Plant in Service	$ 1,593.3	$ 1,590.5
Construction Work in Progress	1.7	1.1
Accumulated Depreciation	$ 225.8	$ 197.5
Rockport Generating Plant (Unit No. 1) [Member] | Indiana Michigan Power Co [Member]
Jointly-owned Electric Facilities
Percent of Ownership	50.00%
Rockport Generating Plant (Unit No. 1) [Member] | Indiana Michigan Power Co [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership	50.00%	50.00%
Utility Plant in Service	$ 1,114.2	$ 1,108.7
Construction Work in Progress	105.5	50.2
Accumulated Depreciation	$ 586.2	514.1
Rockport Generating Plant (Unit No. 1) [Member] | AEP Generating Co [Member]
Jointly-owned Electric Facilities
Percent of Ownership	50.00%
Rockport Generating Plant (Unit No. 2) [Member] | AEP Generating Co [Member]
Jointly-owned Electric Facilities
Percentage Interest in Lease	50.00%
Regulated Operation [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation	$ 21,323.5	20,989.1
Property, Plant and Equipment, Transmission	24,763.4	21,500.5
Property, Plant and Equipment, Distribution	22,440.8	21,192.8
Property, Plant and Equipment, Other	4,369.6	3,770.8
Property, Plant and Equipment, Construction Work in Progress	4,261.2	4,352.6
Accumulated Depreciation	18,778.1	17,743.1
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	$ 58,380.4	$ 54,062.7
Regulated Operation [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation	132 years	132 years	132 years
Depreciable Life Ranges - Transmission	81 years	81 years	100 years
Depreciable Life Ranges - Distribution	78 years	78 years	156 years
Depreciable Life Ranges - Other	75 years	75 years	84 years
Regulated Operation [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation	20 years	20 years	20 years
Depreciable Life Ranges - Transmission	15 years	15 years	15 years
Depreciable Life Ranges - Distribution	7 years	7 years	5 years
Depreciable Life Ranges - Other	5 years	5 years	5 years
Regulated Operation [Member] | Generation [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	5.50%	4.00%	3.70%
Regulated Operation [Member] | Generation [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	2.50%	2.40%	2.30%
Regulated Operation [Member] | Transmission [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	2.60%	2.70%	2.70%
Regulated Operation [Member] | Transmission [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	1.80%	1.60%	1.60%
Regulated Operation [Member] | Distribution [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	3.70%	3.60%	3.70%
Regulated Operation [Member] | Distribution [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	2.70%	2.70%	2.70%
Regulated Operation [Member] | Other Property Class [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	9.50%	9.80%	9.20%
Regulated Operation [Member] | Other Property Class [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	2.60%	2.30%	2.30%
Regulated Operation [Member] | AEP Texas Inc. [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation	$ 0	$ 0
Property, Plant and Equipment, Transmission	4,466.5	3,683.6
Property, Plant and Equipment, Distribution	4,215.2	4,043.2
Property, Plant and Equipment, Other	803.4	724.6
Property, Plant and Equipment, Construction Work in Progress	763.9	836
Accumulated Depreciation	1,465	1,431.2
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	$ 8,784	$ 7,856.2
Regulated Operation [Member] | AEP Texas Inc. [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Transmission	81 years	81 years	81 years
Depreciable Life Ranges - Distribution	70 years	70 years	70 years
Depreciable Life Ranges - Other	50 years	50 years	50 years
Regulated Operation [Member] | AEP Texas Inc. [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Transmission	45 years	45 years	45 years
Depreciable Life Ranges - Distribution	7 years	7 years	7 years
Depreciable Life Ranges - Other	5 years	5 years	5 years
Regulated Operation [Member] | AEP Texas Inc. [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	1.80%	1.70%	1.70%
Regulated Operation [Member] | AEP Texas Inc. [Member] | Distribution [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	3.50%	3.60%	3.60%
Regulated Operation [Member] | AEP Texas Inc. [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	6.30%	6.00%	8.70%
Regulated Operation [Member] | AEP Transmission Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation	$ 0	$ 0
Property, Plant and Equipment, Transmission	8,137.9	6,515.8
Property, Plant and Equipment, Distribution	0	0
Property, Plant and Equipment, Other	268.2	172.6
Property, Plant and Equipment, Construction Work in Progress	1,485.7	1,578.3
Accumulated Depreciation	402.3	271.9
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	$ 9,489.5	$ 7,994.8
Regulated Operation [Member] | AEP Transmission Co [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Transmission	75 years	75 years	100 years
Depreciable Life Ranges - Other	64 years	64 years	84 years
Regulated Operation [Member] | AEP Transmission Co [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Transmission	24 years	20 years	20 years
Depreciable Life Ranges - Other	5 years	5 years	5 years
Regulated Operation [Member] | AEP Transmission Co [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	2.00%	1.90%	1.70%
Regulated Operation [Member] | AEP Transmission Co [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	5.80%	5.60%	6.70%
Regulated Operation [Member] | Appalachian Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation	$ 6,563.7	$ 6,509.6
Property, Plant and Equipment, Transmission	3,584.1	3,317.7
Property, Plant and Equipment, Distribution	4,201.7	3,989.4
Property, Plant and Equipment, Other	542	457.4
Property, Plant and Equipment, Construction Work in Progress	593.4	490.2
Accumulated Depreciation	4,425.6	4,118.9
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	$ 11,059.3	$ 10,645.4
Regulated Operation [Member] | Appalachian Power Co [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation	118 years	112 years	112 years
Depreciable Life Ranges - Transmission	71 years	68 years	68 years
Depreciable Life Ranges - Distribution	57 years	57 years	57 years
Depreciable Life Ranges - Other	55 years	55 years	55 years
Regulated Operation [Member] | Appalachian Power Co [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation	35 years	35 years	35 years
Depreciable Life Ranges - Transmission	15 years	15 years	15 years
Depreciable Life Ranges - Distribution	12 years	10 years	10 years
Depreciable Life Ranges - Other	5 years	5 years	5 years
Regulated Operation [Member] | Appalachian Power Co [Member] | Generation [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	3.20%	3.10%	3.10%
Regulated Operation [Member] | Appalachian Power Co [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	1.80%	1.60%	1.60%
Regulated Operation [Member] | Appalachian Power Co [Member] | Distribution [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	3.70%	3.60%	3.70%
Regulated Operation [Member] | Appalachian Power Co [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	7.20%	7.40%	6.50%
Regulated Operation [Member] | Indiana Michigan Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation	$ 5,099.7	$ 4,887.2
Property, Plant and Equipment, Transmission	1,641.8	1,576.8
Property, Plant and Equipment, Distribution	2,437.6	2,249.7
Property, Plant and Equipment, Other	590.9	543.1
Property, Plant and Equipment, Construction Work in Progress	382.3	465.3
Accumulated Depreciation	3,281.4	3,139.4
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	$ 6,870.9	$ 6,582.7
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation	132 years	132 years	132 years
Depreciable Life Ranges - Transmission	73 years	73 years	75 years
Depreciable Life Ranges - Distribution	75 years	75 years	70 years
Depreciable Life Ranges - Other	50 years	50 years	45 years
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation	20 years	20 years	20 years
Depreciable Life Ranges - Transmission	50 years	50 years	50 years
Depreciable Life Ranges - Distribution	9 years	9 years	10 years
Depreciable Life Ranges - Other	5 years	5 years	5 years
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Generation [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	4.00%	3.40%	2.40%
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	1.90%	1.80%	1.70%
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Distribution [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	3.40%	3.10%	2.70%
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	9.40%	8.90%	8.40%
Regulated Operation [Member] | Ohio Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation	$ 0	$ 0
Property, Plant and Equipment, Transmission	2,686.3	2,544.3
Property, Plant and Equipment, Distribution	5,323.5	4,942.3
Property, Plant and Equipment, Other	754.7	563.7
Property, Plant and Equipment, Construction Work in Progress	394.4	432.1
Accumulated Depreciation	2,261.7	2,217.7
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	$ 6,897.2	$ 6,264.7
Regulated Operation [Member] | Ohio Power Co [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Transmission	60 years	60 years	60 years
Depreciable Life Ranges - Distribution	65 years	65 years	57 years
Depreciable Life Ranges - Other	50 years	50 years	50 years
Regulated Operation [Member] | Ohio Power Co [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Transmission	39 years	39 years	39 years
Depreciable Life Ranges - Distribution	14 years	14 years	5 years
Depreciable Life Ranges - Other	5 years	5 years	5 years
Regulated Operation [Member] | Ohio Power Co [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	2.30%	2.30%	2.30%
Regulated Operation [Member] | Ohio Power Co [Member] | Distribution [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	3.10%	3.00%	2.80%
Regulated Operation [Member] | Ohio Power Co [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	4.90%	6.30%	6.20%
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation	$ 1,574.6	$ 1,577
Property, Plant and Equipment, Transmission	948.5	892.3
Property, Plant and Equipment, Distribution	2,684.8	2,572.8
Property, Plant and Equipment, Other	337.2	298.1
Property, Plant and Equipment, Construction Work in Progress	133.4	94
Accumulated Depreciation	1,579.9	1,472.1
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	$ 4,098.6	$ 3,962.1
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation	75 years	75 years	85 years
Depreciable Life Ranges - Transmission	75 years	75 years	100 years
Depreciable Life Ranges - Distribution	78 years	78 years	156 years
Depreciable Life Ranges - Other	64 years	64 years	84 years
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation	35 years	35 years	35 years
Depreciable Life Ranges - Transmission	45 years	45 years	45 years
Depreciable Life Ranges - Distribution	15 years	15 years	27 years
Depreciable Life Ranges - Other	5 years	5 years	5 years
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Generation [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	2.90%	2.90%	2.40%
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	2.40%	2.30%	2.20%
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Distribution [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	2.90%	2.90%	2.70%
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	5.60%	6.30%	7.40%
Regulated Operation [Member] | Southwestern Electric Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation	$ 4,691.4	$ 4,672.6
Property, Plant and Equipment, Transmission	2,056.5	1,866.9
Property, Plant and Equipment, Distribution	2,270.7	2,178.6
Property, Plant and Equipment, Other	520.6	485.2
Property, Plant and Equipment, Construction Work in Progress	210.1	194.7
Accumulated Depreciation	2,766.2	2,633.5
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	$ 6,983.1	$ 6,764.5
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation	70 years	70 years	70 years
Depreciable Life Ranges - Transmission	73 years	73 years	73 years
Depreciable Life Ranges - Distribution	70 years	70 years	70 years
Depreciable Life Ranges - Other	55 years	55 years	55 years
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation	40 years	40 years	40 years
Depreciable Life Ranges - Transmission	50 years	50 years	50 years
Depreciable Life Ranges - Distribution	25 years	25 years	25 years
Depreciable Life Ranges - Other	5 years	5 years	5 years
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Generation [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	2.50%	2.40%	2.30%
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	2.40%	2.20%	2.30%
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Distribution [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	2.70%	2.70%	2.70%
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	7.60%	8.00%	7.20%
Unregulated Operation [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	$ 1,757.7	$ 1,036.4
Depreciable Life Ranges - Transmission		40 years	40 years
Depreciable Life Ranges - Distribution	40 years	40 years	40 years
Unregulated Operation [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation	59 years	59 years	66 years
Depreciable Life Ranges - Transmission	40 years
Depreciable Life Ranges - Other	50 years	50 years	50 years
Unregulated Operation [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation	15 years	15 years	15 years
Depreciable Life Ranges - Transmission	30 years
Depreciable Life Ranges - Other	5 years	5 years	5 years
Unregulated Operation [Member] | Generation [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	21.20%	22.30%	5.10%
Unregulated Operation [Member] | Generation [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	3.20%	3.40%	2.40%
Unregulated Operation [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	2.50%	2.40%	0.20%
Unregulated Operation [Member] | Distribution [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	2.30%	2.30%	2.30%
Unregulated Operation [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate	17.60%	16.30%	12.10%
Unregulated Operation [Member] | AEP Texas Inc. [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	$ 61.1	$ 135.6
Unregulated Operation [Member] | AEP Transmission Co [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	1.4	1.4
Unregulated Operation [Member] | Appalachian Power Co [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	22.6	22.9
Unregulated Operation [Member] | Indiana Michigan Power Co [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	28.8	28.5
Unregulated Operation [Member] | Ohio Power Co [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	9.8	10.2
Unregulated Operation [Member] | Public Service Co Of Oklahoma [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	4.7	4.6
Unregulated Operation [Member] | Southwestern Electric Power Co [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	$ 112.1	107.3
Unregulated Operation [Member] | Southwestern Electric Power Co [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Other	20 years
Unregulated Operation [Member] | Southwestern Electric Power Co [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Other	3 years
Generation and Marketing [Member]
Depreciation, Depletion and Amortization
Accumulated Depreciation	$ 99	47
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	1,551.8	846.3
Jointly-owned Electric Facilities
Asset Impairments and Other Related Charges	$ 31	$ 47.7	$ 53.5
Generation and Marketing [Member] | Wm. H. Zimmer Generating Station [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership				25.40%

Goodwill (Details)

Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Changes in Carrying Amount of Goodwill
Goodwill	$ 52.5	$ 52.5	$ 52.5
Impairment Losses	0	0
Corporate and Other [Member]
Changes in Carrying Amount of Goodwill
Goodwill	37.1	37.1	37.1
Impairment Losses	0	0
Generation and Marketing [Member]
Changes in Carrying Amount of Goodwill
Goodwill	15.4	15.4	$ 15.4
Impairment Losses	$ 0	$ 0

Revenue from Contracts with C_3

Revenue from Contracts with Customers (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue
Revenue from Contracts with Customers									$ 15,561.4	$ 16,195.7	$ 15,424.9
Revenue, Performance Obligation
Fixed Performance Obligations	$ 1,497.9								1,497.9
Revenue Textuals
Revenue from Related Parties									0	0	0
Revenues	3,616	$ 4,315	$ 3,573.6	$ 4,056.8	$ 3,801.1	$ 4,333.1	$ 4,013.2	$ 4,048.3	15,561.4	16,195.7	15,424.9
2020 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	953								953
2021-2022 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	160.8								160.8
2023-2024 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	160.6								160.6
After 2024 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	223.5								223.5
Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									11,851.9	12,327.8
Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									5,713.6	5,941.2
Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									3,308.2	3,435.1
Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									2,607.2	2,725.3
Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									222.9	226.2
Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									3,444.2	3,435.7
Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,062.4	1,316.2
Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									979.4	766.5
Renewable Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									57.3	50.8
Retail, Trading and Marketing Revenue [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,345.1	1,302.2
Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									316.7	453
Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									15,612.8	16,216.5
Alternative and Other [Member]
Revenue Textuals
Revenues									(51.4)	(20.8)
Alternative [Member]
Revenue Textuals
Revenues									(113.1)	(45.8)
Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									274.9	268.6	229.5
Revenue Textuals
Revenues									61.7	25
AEP Texas Inc. [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,551.6	1,493
Revenue, Performance Obligation
Fixed Performance Obligations	387								387
Current Assets
Affiliated Companies - Contracts with Customers	10.1				15				10.1	15
Revenue Textuals
Revenue from Related Parties									160.5	105.2	65.7
Revenues	391.3	489.3	438	390.7	402	433.4	388.3	371.6	1,709.3	1,595.3	1,538.4
AEP Texas Inc. [Member] | 2020 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	387								387
AEP Texas Inc. [Member] | 2021-2022 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	0								0
AEP Texas Inc. [Member] | 2023-2024 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	0								0
AEP Texas Inc. [Member] | After 2024 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	0								0
AEP Texas Inc. [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,142.3	1,151
AEP Texas Inc. [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									571.5	578.9
AEP Texas Inc. [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									411.5	414.7
AEP Texas Inc. [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									129.4	128
AEP Texas Inc. [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									29.9	29.4
AEP Texas Inc. [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									379.2	313.4
AEP Texas Inc. [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
AEP Texas Inc. [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									379.2	313.4
AEP Texas Inc. [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									30.1	28.6
AEP Texas Inc. [Member] | Alternative and Other [Member]
Revenue Textuals
Revenues									157.7	102.3
AEP Texas Inc. [Member] | Alternative [Member]
Revenue Textuals
Revenues									0.6	(1.3)
AEP Texas Inc. [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									2.9	3.8	2.4
Revenue Textuals
Revenues									157.1	103.6
AEP Transmission Co [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,042.1	832
Revenue, Performance Obligation
Fixed Performance Obligations	1,090.7								1,090.7
Current Assets
Affiliated Companies - Contracts with Customers	66.1				61				66.1	61
Revenue Textuals
Revenue from Related Parties									806.7	598.9	568.1
Revenues	251.3	259.7	266.9	243.5	189.9	194.4	200.1	191.7	1,021.4	776.1	706.9
AEP Transmission Co [Member] | Short-term Contract with Customer [Member]
Current Assets
Affiliated Companies - Contracts with Customers	65.9				58.6				65.9	58.6
AEP Transmission Co [Member] | 2020 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	1,090.7								1,090.7
AEP Transmission Co [Member] | 2021-2022 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	0								0
AEP Transmission Co [Member] | 2023-2024 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	0								0
AEP Transmission Co [Member] | After 2024 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	0								0
AEP Transmission Co [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
AEP Transmission Co [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
AEP Transmission Co [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
AEP Transmission Co [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
AEP Transmission Co [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
AEP Transmission Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,025.5	816.9
AEP Transmission Co [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
AEP Transmission Co [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,025.5	816.9
Revenue Textuals
Revenue from Related Parties									782	646
AEP Transmission Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									16.6	15.1
AEP Transmission Co [Member] | Alternative and Other [Member]
Revenue Textuals
Revenues									(20.7)	(55.9)
AEP Transmission Co [Member] | Alternative [Member]
Revenue Textuals
Revenues									(20.7)	(55.9)
AEP Transmission Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0.1	0.2	0.8
Revenue Textuals
Revenues									0	0
AEP Transmission Co [Member] | Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									214.6	177	138
Appalachian Power Co [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									2,911.1	2,993.2
Revenue, Performance Obligation
Fixed Performance Obligations	225.1								225.1
Current Assets
Affiliated Companies - Contracts with Customers	64.3				73.4				64.3	73.4
Revenue Textuals
Revenue from Related Parties									205.3	181.4	172
Revenues	720.6	755.5	655.8	792.8	718.1	762	667	820.4	2,924.7	2,967.5	2,934.2
Appalachian Power Co [Member] | Short-term Contract with Customer [Member]
Current Assets
Affiliated Companies - Contracts with Customers	47.3				52.5				47.3	52.5
Appalachian Power Co [Member] | 2020 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	158								158
Appalachian Power Co [Member] | 2021-2022 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	32.3								32.3
Appalachian Power Co [Member] | 2023-2024 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	23.2								23.2
Appalachian Power Co [Member] | After 2024 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	11.6								11.6
Appalachian Power Co [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									2,494.2	2,604.8
Appalachian Power Co [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,266.9	1,342.7
Appalachian Power Co [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									559.9	580.4
Appalachian Power Co [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									592.2	604.3
Appalachian Power Co [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									75.2	77.4
Appalachian Power Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									355.1	333.1
Appalachian Power Co [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									251.5	250.4
Revenue Textuals
Revenue from Related Parties									129	134
Appalachian Power Co [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									103.6	82.7
Appalachian Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									61.8	55.3
Appalachian Power Co [Member] | Alternative and Other [Member]
Revenue Textuals
Revenues									13.6	(25.7)
Appalachian Power Co [Member] | Alternative [Member]
Revenue Textuals
Revenues									13.6	(23.8)
Appalachian Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									11.2	9	13.2
Revenue Textuals
Revenues									0	(1.9)
Indiana Michigan Power Co [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									2,308.1	2,381
Revenue, Performance Obligation
Fixed Performance Obligations	51.6								51.6
Current Assets
Affiliated Companies - Contracts with Customers	53.7				75				53.7	75
Revenue Textuals
Revenue from Related Parties									10.5	22.1	1.8
Revenues	538.2	611.1	543.1	614.3	574.5	629.7	589.7	576.8	2,306.7	2,370.7	2,121.2
Indiana Michigan Power Co [Member] | Short-term Contract with Customer [Member]
Current Assets
Affiliated Companies - Contracts with Customers	37.1				35.3				37.1	35.3
Indiana Michigan Power Co [Member] | 2020 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	29.6								29.6
Indiana Michigan Power Co [Member] | 2021-2022 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	8.8								8.8
Indiana Michigan Power Co [Member] | 2023-2024 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	8.8								8.8
Indiana Michigan Power Co [Member] | After 2024 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	4.4								4.4
Indiana Michigan Power Co [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,782.2	1,787.8
Indiana Michigan Power Co [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									730	730
Indiana Michigan Power Co [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									494.2	485
Indiana Michigan Power Co [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									550.7	565.6
Indiana Michigan Power Co [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									7.3	7.2
Indiana Michigan Power Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									427.5	493.6
Indiana Michigan Power Co [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									402.4	470.5
Indiana Michigan Power Co [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									25.1	23.1
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									98.4	99.6
Indiana Michigan Power Co [Member] | Alternative and Other [Member]
Revenue Textuals
Revenues									(1.4)	(10.3)
Indiana Michigan Power Co [Member] | Alternative [Member]
Revenue Textuals
Revenues									(1.4)	(2.1)
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									10.7	12.6	14.3
Revenue Textuals
Revenue from Related Parties									73	70
Revenues									0	(8.2)
Ohio Power Co [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									2,748.8	3,079.9
Revenue, Performance Obligation
Fixed Performance Obligations	61								61
Current Assets
Affiliated Companies - Contracts with Customers	59.3				70.8				59.3	70.8
Revenue Textuals
Revenue from Related Parties									27.3	21	24.4
Revenues	643.6	710.6	606.6	836.8	745.4	778.3	748.8	790.9	2,797.6	3,063.4	2,883.9
Ohio Power Co [Member] | Short-term Contract with Customer [Member]
Current Assets
Affiliated Companies - Contracts with Customers	33.9				46.1				33.9	46.1
Ohio Power Co [Member] | 2020 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	61								61
Ohio Power Co [Member] | 2021-2022 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	0								0
Ohio Power Co [Member] | 2023-2024 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	0								0
Ohio Power Co [Member] | After 2024 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	0								0
Ohio Power Co [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									2,553.5	2,845.3
Ohio Power Co [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,502	1,611.6
Ohio Power Co [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									738.5	835.6
Ohio Power Co [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									299.9	385.2
Ohio Power Co [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									13.1	12.9
Ohio Power Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									56	58.5
Ohio Power Co [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Ohio Power Co [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									56	58.5
Ohio Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									139.3	176.1
Ohio Power Co [Member] | Alternative and Other [Member]
Revenue Textuals
Revenues									48.8	(16.5)
Ohio Power Co [Member] | Alternative [Member]
Revenue Textuals
Revenues									31.7	(20.8)
Ohio Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									10.8	8.6	6
Revenue Textuals
Revenues									17.1	4.3
Public Service Co Of Oklahoma [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,512.8	1,536.4
Revenue, Performance Obligation
Fixed Performance Obligations	11.7								11.7
Current Assets
Affiliated Companies - Contracts with Customers	20.6				26.2				20.6	26.2
Revenue Textuals
Revenue from Related Parties									6.1	5.4	4.3
Revenues	307.9	493	348.1	332.8	330.8	481.4	398.3	336.8	1,481.8	1,547.3	1,427.2
Public Service Co Of Oklahoma [Member] | Short-term Contract with Customer [Member]
Current Assets
Affiliated Companies - Contracts with Customers	9.7				12.4				9.7	12.4
Public Service Co Of Oklahoma [Member] | 2020 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	11.7								11.7
Public Service Co Of Oklahoma [Member] | 2021-2022 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	0								0
Public Service Co Of Oklahoma [Member] | 2023-2024 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	0								0
Public Service Co Of Oklahoma [Member] | After 2024 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	0								0
Public Service Co Of Oklahoma [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,423.8	1,440.8
Public Service Co Of Oklahoma [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									650.2	659
Public Service Co Of Oklahoma [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									388.5	394.2
Public Service Co Of Oklahoma [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									303.5	304
Public Service Co Of Oklahoma [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									81.6	83.6
Public Service Co Of Oklahoma [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									67	76.5
Public Service Co Of Oklahoma [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									39.5	36.3
Public Service Co Of Oklahoma [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									27.5	40.2
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									22	19.1
Public Service Co Of Oklahoma [Member] | Alternative and Other [Member]
Revenue Textuals
Revenues									(31)	10.9
Public Service Co Of Oklahoma [Member] | Alternative [Member]
Revenue Textuals
Revenues									(31)	10.9
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									6.1	4.3	5.4
Revenue Textuals
Revenues									0	0
Southwestern Electric Power Co [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,799.2	1,817
Revenue, Performance Obligation
Fixed Performance Obligations	30.4								30.4
Current Assets
Affiliated Companies - Contracts with Customers	34.5				28.8				34.5	28.8
Revenue Textuals
Revenue from Related Parties									36.9	35.1	25.9
Revenues	408.8	$ 545.5	$ 375.5	$ 421.1	410.1	$ 535.3	$ 457.1	$ 419.4	1,750.9	1,821.9	1,779.9
Southwestern Electric Power Co [Member] | Short-term Contract with Customer [Member]
Current Assets
Affiliated Companies - Contracts with Customers	17.6				$ 16.3				17.6	16.3
Southwestern Electric Power Co [Member] | 2020 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	30.4								30.4
Southwestern Electric Power Co [Member] | 2021-2022 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	0								0
Southwestern Electric Power Co [Member] | 2023-2024 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	0								0
Southwestern Electric Power Co [Member] | After 2024 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations	$ 0								0
Southwestern Electric Power Co [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,471.7	1,467.8
Southwestern Electric Power Co [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									638.6	641.6
Southwestern Electric Power Co [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									485.4	483.9
Southwestern Electric Power Co [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									338.7	333.7
Southwestern Electric Power Co [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									9	8.6
Southwestern Electric Power Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									301.4	325.2
Southwestern Electric Power Co [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									194.7	216.8
Southwestern Electric Power Co [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									106.7	108.4
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									26.1	24
Southwestern Electric Power Co [Member] | Alternative and Other [Member]
Revenue Textuals
Revenues									(48.3)	4.9
Southwestern Electric Power Co [Member] | Alternative [Member]
Revenue Textuals
Revenues									(48.3)	4.9
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1.4	1.6	1.9
Revenue Textuals
Revenues									0	0
Consolidation Eliminations [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0	0
Revenue Textuals
Revenue from Related Parties									(1,314.8)	(942.4)	(949)
Revenues									(1,314.8)	(942.4)	(949)
Consolidation Eliminations [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									(0.9)	0
Consolidation Eliminations [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Consolidation Eliminations [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Consolidation Eliminations [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									(0.9)	0
Consolidation Eliminations [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Consolidation Eliminations [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									(960.6)	(865.1)
Consolidation Eliminations [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	(7.3)
Consolidation Eliminations [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									(825)	(737.1)
Consolidation Eliminations [Member] | Renewable Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Consolidation Eliminations [Member] | Retail, Trading and Marketing Revenue [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									(135.6)	(120.7)
Consolidation Eliminations [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									(147.1)	(32)
Consolidation Eliminations [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									(1,108.6)	(897.1)
Consolidation Eliminations [Member] | Alternative and Other [Member]
Revenue Textuals
Revenues									(206.2)	(45.3)
Consolidation Eliminations [Member] | Alternative [Member]
Revenue Textuals
Revenues									(66.9)	52.7
Consolidation Eliminations [Member] | Other Revenues [Member]
Revenue Textuals
Revenue from Related Parties										98
Revenues									(139.3)	(98)
Consolidation Eliminations [Member] | AEP Transmission Co [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0	0
Revenue Textuals
Revenue from Related Parties									0	0	0
Revenues									0	0	0
Consolidation Eliminations [Member] | AEP Transmission Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0	0
Vertically Integrated Utilities [Member]
Revenue Textuals
Revenue from Related Parties									121.4	88.8	96.9
Revenues									9,367.1	9,645.5	9,192
Vertically Integrated Utilities [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									8,157.1	8,331.5
Vertically Integrated Utilities [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									3,643.7	3,751.8
Vertically Integrated Utilities [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									2,155.3	2,183.4
Vertically Integrated Utilities [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									2,179	2,212.8
Vertically Integrated Utilities [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									179.1	183.5
Vertically Integrated Utilities [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,099.7	1,182
Vertically Integrated Utilities [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									807.6	899.8
Vertically Integrated Utilities [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									292.1	282.2
Vertically Integrated Utilities [Member] | Renewable Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Vertically Integrated Utilities [Member] | Retail, Trading and Marketing Revenue [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Vertically Integrated Utilities [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									168.2	158.4
Vertically Integrated Utilities [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									9,425	9,671.9
Vertically Integrated Utilities [Member] | Alternative and Other [Member]
Revenue Textuals
Revenues									(57.9)	(26.4)
Vertically Integrated Utilities [Member] | Alternative [Member]
Revenue Textuals
Revenues									(57.9)	(15.9)
Vertically Integrated Utilities [Member] | Other Revenues [Member]
Revenue Textuals
Revenues									0	(10.5)
Transmission And Distribution Utilities [Member]
Revenue Textuals
Revenue from Related Parties									163.5	100.8	90.4
Revenues									4,482.5	4,653.1	4,419.3
Transmission And Distribution Utilities [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									3,695.7	3,996.3
Transmission And Distribution Utilities [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									2,069.9	2,189.4
Transmission And Distribution Utilities [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,152.9	1,251.7
Transmission And Distribution Utilities [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									429.1	512.5
Transmission And Distribution Utilities [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									43.8	42.7
Transmission And Distribution Utilities [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									435.1	372.1
Transmission And Distribution Utilities [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Transmission And Distribution Utilities [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									435.1	372.1
Transmission And Distribution Utilities [Member] | Renewable Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Transmission And Distribution Utilities [Member] | Retail, Trading and Marketing Revenue [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Transmission And Distribution Utilities [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									169.4	204.6
Transmission And Distribution Utilities [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									4,300.2	4,573
Transmission And Distribution Utilities [Member] | Alternative and Other [Member]
Revenue Textuals
Revenues									182.3	80.1
Transmission And Distribution Utilities [Member] | Alternative [Member]
Revenue Textuals
Revenues									32.3	(22.2)
Transmission And Distribution Utilities [Member] | Other Revenues [Member]
Revenue Textuals
Revenues									150	102.3
AEP Transmission Holdco [Member]
Revenue Textuals
Revenues									1,073.2	804.1
AEP Transmission Holdco [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
AEP Transmission Holdco [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
AEP Transmission Holdco [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
AEP Transmission Holdco [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
AEP Transmission Holdco [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
AEP Transmission Holdco [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,077.2	849.3
AEP Transmission Holdco [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
AEP Transmission Holdco [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,077.2	849.3
Revenue Textuals
Revenue from Related Parties									794	643
AEP Transmission Holdco [Member] | Renewable Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
AEP Transmission Holdco [Member] | Retail, Trading and Marketing Revenue [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
AEP Transmission Holdco [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									16.6	15.2
AEP Transmission Holdco [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,093.8	864.5
AEP Transmission Holdco [Member] | Alternative and Other [Member]
Revenue Textuals
Revenues									(20.6)	(60.4)
AEP Transmission Holdco [Member] | Alternative [Member]
Revenue Textuals
Revenues									(20.6)	(60.4)
AEP Transmission Holdco [Member] | Other Revenues [Member]
Revenue Textuals
Revenues									0	0
Generation and Marketing [Member]
Revenue Textuals
Revenue from Related Parties									135.8	122.2	103.7
Revenues									1,857.6	1,940.3	1,875.1
Generation and Marketing [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Generation and Marketing [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Generation and Marketing [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Generation and Marketing [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Generation and Marketing [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Generation and Marketing [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,792.8	1,897.4
Generation and Marketing [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									254.8	423.7
Generation and Marketing [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Generation and Marketing [Member] | Renewable Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									57.3	50.8
Generation and Marketing [Member] | Retail, Trading and Marketing Revenue [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,480.7	1,422.9
Revenue Textuals
Revenue from Related Parties									136	121
Generation and Marketing [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									4.9	20.6
Generation and Marketing [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									1,797.7	1,918
Generation and Marketing [Member] | Alternative and Other [Member]
Revenue Textuals
Revenues									59.9	22.3
Generation and Marketing [Member] | Alternative [Member]
Revenue Textuals
Revenues									0	0
Generation and Marketing [Member] | Other Revenues [Member]
Revenue Textuals
Revenues									59.9	22.3
Other Segments [Member]
Revenue Textuals
Revenue from Related Parties									81.1	75.1	69.7
Revenues									95.8	95.1	120.8
Other Segments [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Other Segments [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Other Segments [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Other Segments [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Other Segments [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Other Segments [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Other Segments [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Other Segments [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Other Segments [Member] | Renewable Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Other Segments [Member] | Retail, Trading and Marketing Revenue [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									0	0
Other Segments [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									104.7	86.2
Other Segments [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									104.7	86.2
Other Segments [Member] | Alternative and Other [Member]
Revenue Textuals
Revenues									(8.9)	8.9
Other Segments [Member] | Alternative [Member]
Revenue Textuals
Revenues									0	0
Other Segments [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers									14.7	20	$ 51.1
Revenue Textuals
Revenues									$ (8.9)	$ 8.9

Unaudited Quarterly Financial_3

Unaudited Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Summary of Unaudited Quarterly Financial Information
Total Revenues	$ 3,616	$ 4,315	$ 3,573.6	$ 4,056.8	$ 3,801.1	$ 4,333.1	$ 4,013.2	$ 4,048.3	$ 15,561.4	$ 16,195.7	$ 15,424.9
Operating Income (Loss)	294.7	958.2	551	788.4	551.1	668.6	757	706	2,592.3	2,682.7	3,525
Net Income (Loss)	152.7	733.9	459.1	574.1	364.8	579.7	530.1	456.7	1,919.8	1,931.3	1,928.9
Amounts Attributable to Common Shareholders
Earnings (Loss) Attributable To Common Shareholders	$ 153.5	$ 733.5	$ 461.3	$ 572.8	$ 363.4	$ 577.6	$ 528.4	$ 454.4	$ 1,921.1	$ 1,923.8	$ 1,912.6
Basic Earnings (Loss) per Share Attributable to AEP Common Shareholders:
Basic Earnings (Loss) per Share Attributable to AEP Common Shareholders from Continuing Operations	$ 0.31	$ 1.49	$ 0.93	$ 1.16	$ 0.74	$ 1.17	$ 1.07	$ 0.92
Total Basic Earnings (Loss) per Share Attributable to AEP Common Shareholders									$ 3.89	$ 3.90	$ 3.89
Diluted Earnings (Loss) per Share Attributable to AEP Common Shareholders:
Diluted Earnings (Loss) per Share Attributable to AEP Common Shareholders from Continuing Operations	$ 0.31	$ 1.48	$ 0.93	$ 1.16	$ 0.74	$ 1.17	$ 1.07	$ 0.92
Total Diluted Earnings (Loss) Per Share Attributable to AEP Common Shareholders									$ 3.88	$ 3.90	$ 3.88
AEP Texas Inc. [Member]
Summary of Unaudited Quarterly Financial Information
Total Revenues	$ 391.3	$ 489.3	$ 438	$ 390.7	$ 402	$ 433.4	$ 388.3	$ 371.6	$ 1,709.3	$ 1,595.3	$ 1,538.4
Operating Income (Loss)	4.3	118.2	38.7	70.8	84.3	94	86.2	81.8	232	346.3	416.1
Net Income (Loss)	(13.7)	77	80.6	34.4	60.2	57.8	46.5	46.8	178.3	211.3	310.5
AEP Transmission Co [Member]
Summary of Unaudited Quarterly Financial Information
Total Revenues	251.3	259.7	266.9	243.5	189.9	194.4	200.1	191.7	1,021.4	776.1	706.9
Operating Income (Loss)	122.3	142.3	161	141.6	91.5	97	110.5	111.1	567.2	410.1	432.9
Net Income (Loss)	91.8	107.6	136	104.3	71.7	78.1	82	84.1	439.7	315.9	270.7
Appalachian Power Co [Member]
Summary of Unaudited Quarterly Financial Information
Total Revenues	720.6	755.5	655.8	792.8	718.1	762	667	820.4	2,924.7	2,967.5	2,934.2
Operating Income (Loss)	25.7	142.6	76.9	152.1	108.1	49.8	132.6	193	397.3	483.5	690.3
Net Income (Loss)	12.8	104.3	55.5	133.7	77.8	87.1	77.4	125.5	306.3	367.8	331.3
Indiana Michigan Power Co [Member]
Summary of Unaudited Quarterly Financial Information
Total Revenues	538.2	611.1	543.1	614.3	574.5	629.7	589.7	576.8	2,306.7	2,370.7	2,121.2
Operating Income (Loss)	40.6	107.3	77.9	115	52.2	110.2	117.4	97.4	340.8	377.2	347.2
Net Income (Loss)	21.4	88.8	60.3	98.9	29.7	72.7	94.7	64.2	269.4	261.3	186.7
Ohio Power Co [Member]
Summary of Unaudited Quarterly Financial Information
Total Revenues	643.6	710.6	606.6	836.8	745.4	778.3	748.8	790.9	2,797.6	3,063.4	2,883.9
Operating Income (Loss)	63	98.6	77.1	162.5	118.2	79.9	104.4	117.3	401.2	419.8	565.7
Net Income (Loss)	49.4	69.1	50.6	128	88.4	88.7	68.8	79.6	297.1	325.5	323.9
Public Service Co Of Oklahoma [Member]
Summary of Unaudited Quarterly Financial Information
Total Revenues	307.9	493	348.1	332.8	330.8	481.4	398.3	336.8	1,481.8	1,547.3	1,427.2
Operating Income (Loss)	1.8	120	56.6	20.9	2.9	78.5	57.2	3.9	199.3	142.5	171.5
Net Income (Loss)	(10.8)	100.3	41.9	6.2	(6.6)	60.4	36.6	(7.2)	137.6	83.2	72
Southwestern Electric Power Co [Member]
Summary of Unaudited Quarterly Financial Information
Total Revenues	408.8	545.5	375.5	421.1	410.1	535.3	457.1	419.4	1,750.9	1,821.9	1,779.9
Operating Income (Loss)	33.9	134.7	33	54.1	38.5	127.1	70.5	41.6	255.7	277.7	304
Net Income (Loss)	14.6	111.3	7.3	29	10.5	89.6	38.7	13.4	162.2	152.2	137.5
Amounts Attributable to Common Shareholders
Earnings (Loss) Attributable To Common Shareholders	$ 14.1	$ 110.5	$ 6.2	$ 27.8	$ 9.6	$ 88.2	$ 37.6	$ 11.8	$ 158.6	$ 147.2	$ 124.7