Appalachian Power 10-K 25 Feb 21 2020 FY Annual report Financial data

Cover

Cover	12 Months Ended
	Dec. 31, 2020USD ($)shares
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
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
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float | $	$ 39,549,558,010
Entity Common Stock, Shares Outstanding	496,604,194
Entity Central Index Key	0000004904
Amendment Flag	false
Document Fiscal Year Focus	2020
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	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell 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	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell 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 Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell 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 Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell 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	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell 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 Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell 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	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding	3,680,000,000
Entity Central Index Key	0000092487
The NASDAQ Stock Market | Common Stock, $6.50 par value [Member]
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, $6.50 par value
Trading Symbol	AEP
Security Exchange Name	NASDAQ
The NASDAQ Stock Market | 6.125% Corporate Units [Member]
Entity Information [Line Items]
Title of 12(b) Security	6.125% Corporate Units
Trading Symbol	AEPPL
Security Exchange Name	NASDAQ
The NASDAQ Stock Market | 6.125% Corporate Units
Entity Information [Line Items]
Title of 12(b) Security	6.125% Corporate Units
Trading Symbol	AEPPZ
Security Exchange Name	NASDAQ

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Revenues
Revenue from Contracts with Customers	$ 14,918.5		$ 15,561.4		$ 16,195.7
Sales to AEP Affiliates	0		0		0
TOTAL REVENUES	14,918.5		15,561.4		16,195.7
Expenses
Other Operation	2,572.4		2,743.7		2,979.2
Maintenance	1,010.4		1,213.9		1,247.4
Asset Impairments and Other Related Charges	0		156.4		70.6
Depreciation and Amortization	2,682.8		2,514.5		2,286.6
Taxes Other Than Income Taxes	1,295.5		1,234.5		1,142.7
TOTAL EXPENSES	11,930.8		12,969.1		13,513
OPERATING INCOME (LOSS)	2,987.7		2,592.3		2,682.7
Other Income (Expense):
Other Income	57		26.6		18.2
Allowance for Equity Funds Used During Construction	148.1		168.4		132.5
Non-Service Cost Components of Net Periodic Benefit Cost	119		120		124.5
Interest Expense	(1,165.7)		(1,072.5)		(984.4)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	2,146.1		1,834.8		1,973.5
Income Tax Expense (Benefit)	40.5		(12.9)		115.3
Equity Earnings (Loss) of Unconsolidated Subsidiaries	91.1		72.1		73.1
Net Income (Loss)	2,196.7		1,919.8		1,931.3
Net Income Attributable to Noncontrolling Interests	(3.4)		(1.3)		7.5
EARNINGS ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ 2,200.1		$ 1,921.1		$ 1,923.8
Earnings Per Share
WEIGHTED AVERAGE NUMBER OF BASIC AEP COMMON SHARES OUTSTANDING	495,718,223		493,694,345		492,774,600
Total Basic Earnings (Loss) per Share Attributable to AEP Common Shareholders	$ 4.44		$ 3.89		$ 3.90
WEIGHTED AVERAGE NUMBER OF DILUTED AEP COMMON SHARES OUTSTANDING	497,226,867		495,306,238		493,758,277
TOTAL DILUTED EARNINGS PER SHARE ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS	$ 4.42		$ 3.88		$ 3.90
Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	$ 8,753.2		$ 9,245.7		$ 9,556.7
Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	4,238.7		4,319		4,552.3
Generation and Marketing Revenues [Member]
Revenues
Revenue from Contracts with Customers	1,621		1,721.8		1,818.1
Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	305.6		274.9		268.6
TOTAL REVENUES	61.5	[1]	61.7	[2]	25	[3]
Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	1,439.3		1,940.9		2,359.4
Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	2,930.4		3,165.2		3,427.1
AEP Texas Inc. [Member]
Revenues
Revenue from Contracts with Customers	1,528		1,551.6		1,493
Sales to AEP Affiliates	90.8		160.5		105.2
TOTAL REVENUES	1,618.9		1,709.3		1,595.3
Expenses
Other Operation	488.9		492		488.9
Maintenance	80.5		158.8		89.4
Asset Impairments and Other Related Charges	0		32.5		0
Depreciation and Amortization	529.8		622.3		499.6
Taxes Other Than Income Taxes	136.4		140.6		132.6
TOTAL EXPENSES	1,249.3		1,477.3		1,249
OPERATING INCOME (LOSS)	369.6		232		346.3
Other Income (Expense):
Interest Income	1.4		3.4		0.8
Allowance for Equity Funds Used During Construction	19.4		15.2		20
Non-Service Cost Components of Net Periodic Benefit Cost	11.2		11.3		12.3
Interest Expense	(171.8)		(137.2)		(147.3)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	229.8		124.7		232.1
Income Tax Expense (Benefit)	(11.2)		(53.6)		20.8
Net Income (Loss)	241		178.3		211.3
AEP Texas Inc. [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	1,524.9		1,545.9		1,486.3
AEP Texas Inc. [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	3.2		2.9		3.8
TOTAL REVENUES	87.5	[4]	157.1	[5]	103.6	[6]
AEP Texas Inc. [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	13.7		31.1		38.5
AEP Transmission Co [Member]
Revenues
Revenue from Contracts with Customers	1,232.7		1,042.1		832
Sales to AEP Affiliates	896.3		806.7		598.9
TOTAL REVENUES	1,145.7		1,021.4		776.1
Expenses
Other Operation	99.8		93.9		83.8
Maintenance	10.2		15.4		10.5
Depreciation and Amortization	249		176		133.9
Taxes Other Than Income Taxes	205.2		168.9		137.8
TOTAL EXPENSES	564.2		454.2		366
OPERATING INCOME (LOSS)	581.5		567.2		410.1
Other Income (Expense):
Interest Income	2.4		3		2.5
Allowance for Equity Funds Used During Construction	74		84.3		70.6
Interest Expense	(127.8)		(97.4)		(83.2)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	530.1		557.1		400
Income Tax Expense (Benefit)	106.7		117.4		84.1
Net Income (Loss)	423.4		439.7		315.9
AEP Transmission Co [Member] | Transmission [Member]
Revenues
Revenue from Contracts with Customers	248.8		214.6		177
AEP Transmission Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.6		0.1		0.2
TOTAL REVENUES	0	[4]	0	[5]	0	[6]
Appalachian Power Co [Member]
Revenues
Revenue from Contracts with Customers	2,809.2		2,911.1		2,993.2
Sales to AEP Affiliates	174.7		205.3		181.4
TOTAL REVENUES	2,796.2		2,924.7		2,967.5
Expenses
Other Operation	530.5		567.6		511.6
Maintenance	226.8		255.4		316.9
Asset Impairments and Other Related Charges	0		92.9		0
Re-Establishment of Regulatory Asset - Coal Fired Generation	(49)		0		0
Depreciation and Amortization	507.5		466.8		428.4
Taxes Other Than Income Taxes	150.2		146.2		134.7
TOTAL EXPENSES	2,239.6		2,527.4		2,484
OPERATING INCOME (LOSS)	556.6		397.3		483.5
Other Income (Expense):
Interest Income	1.6		2.4		1.8
Carrying Costs Income	0		0		1.3
Allowance for Equity Funds Used During Construction	14.6		16.6		13.2
Non-Service Cost Components of Net Periodic Benefit Cost	18.8		17		17.9
Interest Expense	(217.6)		(205)		(194.8)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	374		228.3		322.9
Income Tax Expense (Benefit)	4.3		(78)		(44.9)
Net Income (Loss)	369.7		306.3		367.8
Appalachian Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	2,610.9		2,708.2		2,777.1
Appalachian Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	10.6		11.2		9
TOTAL REVENUES	0	[4]	0	[5]	(1.9)	[6]
Appalachian Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	513.3		607.5		588.9
Appalachian Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	360.3		391		503.5
Indiana Michigan Power Co [Member]
Revenues
Revenue from Contracts with Customers	2,236		2,308.1		2,381
Sales to AEP Affiliates	10.5		10.5		22.1
Other Revenues - Affiliated	60.8		63.4		63.4
TOTAL REVENUES	2,241.8		2,306.7		2,370.7
Expenses
Purchased Electricity from AEP Affiliates	172.8		214.9		237.9
Other Operation	650		641.2		585.4
Maintenance	193.2		231.2		238.1
Depreciation and Amortization	411.6		350.6		293.1
Taxes Other Than Income Taxes	107.1		105.1		98.9
TOTAL EXPENSES	1,878.9		1,965.9		1,993.5
OPERATING INCOME (LOSS)	362.9		340.8		377.2
Other Income (Expense):
Other Income	10		18.2		19.2
Allowance for Equity Funds Used During Construction	11.5		19.4		11.9
Non-Service Cost Components of Net Periodic Benefit Cost	16.7		17.7		18.1
Interest Expense	(112.3)		(117.9)		(124.1)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	277.3		258.8		290.4
Income Tax Expense (Benefit)	(7.5)		(10.6)		29.1
Net Income (Loss)	284.8		269.4		261.3
Indiana Michigan Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	2,165.3		2,222.1		2,272.6
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	5.2		10.7		12.6
Sales to AEP Affiliates	69		73		70
TOTAL REVENUES	0	[4]	0	[5]	(8.2)	[6]
Indiana Michigan Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	162		190.6		318.3
Indiana Michigan Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	182.2		232.3		221.8
Ohio Power Co [Member]
Revenues
Revenue from Contracts with Customers	2,665		2,748.8		3,079.9
Sales to AEP Affiliates	41.5		27.3		21
TOTAL REVENUES	2,749.1		2,797.6		3,063.4
Expenses
Purchased Electricity from AEP Affiliates	119.7		156		135.3
Amortization of Generation Deferrals	0		65.3		223.9
Other Operation	822.6		742.6		771.3
Maintenance	127.1		150.1		156
Depreciation and Amortization	276.6		240.9		259.7
Taxes Other Than Income Taxes	450.2		434.2		412.8
TOTAL EXPENSES	2,345.4		2,396.4		2,643.6
OPERATING INCOME (LOSS)	403.7		401.2		419.8
Other Income (Expense):
Interest Income	1		3.2		3.4
Carrying Costs Income	1.6		1		1.7
Allowance for Equity Funds Used During Construction	12.5		18.2		9.8
Non-Service Cost Components of Net Periodic Benefit Cost	15		14.6		15.5
Interest Expense	(117.2)		(106.2)		(100.7)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	316.6		332		349.5
Income Tax Expense (Benefit)	45.2		34.9		24
Net Income (Loss)	271.4		297.1		325.5
Ohio Power Co [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	2,698.6		2,759.5		3,033.8
Ohio Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	9		10.8		8.6
TOTAL REVENUES	17.5	[4]	17.1	[5]	4.3	[6]
Ohio Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	549.2		607.3		684.6
Public Service Co Of Oklahoma [Member]
Revenues
Revenue from Contracts with Customers	1,263.9		1,512.8		1,536.4
Sales to AEP Affiliates	5.2		6.1		5.4
TOTAL REVENUES	1,266.1		1,481.8		1,547.3
Expenses
Other Operation	327.3		315		372.8
Maintenance	98.4		100.7		104.8
Depreciation and Amortization	173.5		169.5		164
Taxes Other Than Income Taxes	47.5		43.3		42.8
TOTAL EXPENSES	1,090.2		1,282.5		1,404.8
OPERATING INCOME (LOSS)	175.9		199.3		142.5
Other Income (Expense):
Interest Income	0.1		1.2		0.1
Allowance for Equity Funds Used During Construction	4		2.7		0.4
Non-Service Cost Components of Net Periodic Benefit Cost	8.5		8.4		8.7
Interest Expense	(60.3)		(66.5)		(63.5)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	128.2		145.1		88.2
Income Tax Expense (Benefit)	5.2		7.5		5
Net Income (Loss)	123		137.6		83.2
Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	1,246.1		1,469.6		1,537.6
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	14.8		6.1		4.3
TOTAL REVENUES	0	[4]	0	[5]	0	[6]
Public Service Co Of Oklahoma [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	15.6		195.1		240.5
Public Service Co Of Oklahoma [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	427.9		458.9		479.9
Southwestern Electric Power Co [Member]
Revenues
Revenue from Contracts with Customers	1,735.3		1,799.2		1,817
Sales to AEP Affiliates	41		36.9		35.1
Provision for Refund	(2)		(32)		(6.7)
TOTAL REVENUES	1,738.5		1,750.9		1,821.9
Expenses
Other Operation	338.3		348		384.2
Maintenance	129.7		145.6		141.5
Depreciation and Amortization	272.7		249.1		239.5
Taxes Other Than Income Taxes	102.8		100.2		99.6
TOTAL EXPENSES	1,448		1,495.2		1,544.2
OPERATING INCOME (LOSS)	290.5		255.7		277.7
Other Income (Expense):
Interest Income	2.1		2.6		5.4
Allowance for Equity Funds Used During Construction	7.7		6.8		6
Non-Service Cost Components of Net Periodic Benefit Cost	8.4		8.5		8.7
Interest Expense	(118.5)		(119.1)		(127.9)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)	190.2		154.5		169.9
Income Tax Expense (Benefit)	9.4		(4.7)		20.4
Equity Earnings (Loss) of Unconsolidated Subsidiaries	2.9		3		2.7
Net Income (Loss)	183.7		162.2		152.2
Net Income Attributable to Noncontrolling Interests	2.9		3.6		5
EARNINGS ATTRIBUTABLE TO COMMON SHAREHOLDERS	180.8		158.6		147.2
Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	1,696.6		1,744.6		1,791.9
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.9		1.4		1.6
TOTAL REVENUES	0	[4]	0	[5]	0	[6]
Southwestern Electric Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Expenses
Cost of Goods and Services Sold	443.5		472.8		502.3
Southwestern Electric Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	$ 161		$ 179.5		$ 177.1
[1]	Amounts include affiliated and nonaffiliated revenues.
[2]	Amounts include affiliated and nonaffiliated revenues.
[3]	Amounts include affiliated and nonaffiliated revenues.
[4]	Amounts include affiliated and nonaffiliated revenues.
[5]	Amounts include affiliated and nonaffiliated revenues.
[6]	Amounts include affiliated and nonaffiliated revenues.

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net Income (Loss)	$ 2,196.7	$ 1,919.8	$ 1,931.3
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax	6.9	(79.4)	14.6
Amortization of Pension and OPEB Deferred Costs, Net of Tax	(7)	(5.6)	(5.3)
Pension and OPEB Funded Status, Net of Tax	62.7	57.7	(33)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)	62.6	(27.3)	(23.7)
TOTAL COMPREHENSIVE INCOME (LOSS)	2,259.3	1,892.5	1,907.6
Total Comprehensive Income Attributable to Noncontrolling Interest	(3.4)	(1.3)	7.5
TOTAL COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO SHAREHOLDERS	2,262.7	1,893.8	1,900.1
Cash Flow Hedges, Tax	1.8	(21.1)	3.9
Amortization of Pension and OPEB Deferred Costs, Tax	(1.9)	(1.5)	(1.4)
Pension and OPEB Funded Status, Tax	16.7	15.3	(8.8)
AEP Texas Inc. [Member]
Net Income (Loss)	241	178.3	211.3
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax	1.1	1	1
Amortization of Pension and OPEB Deferred Costs, Net of Tax	0.2	0.2	0.2
Pension and OPEB Funded Status, Net of Tax	2.6	1.1	(1)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)	3.9	2.3	0.2
TOTAL COMPREHENSIVE INCOME (LOSS)	244.9	180.6	211.5
Cash Flow Hedges, Tax	0.3	0.3	0.3
Amortization of Pension and OPEB Deferred Costs, Tax	0	0	0.1
Pension and OPEB Funded Status, Tax	0.7	0.3	(0.3)
AEP Transmission Co [Member]
Net Income (Loss)	423.4	439.7	315.9
Appalachian Power Co [Member]
Net Income (Loss)	369.7	306.3	367.8
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax	(1.7)	(0.9)	(0.9)
Amortization of Pension and OPEB Deferred Costs, Net of Tax	(3.8)	(2.5)	(3.1)
Pension and OPEB Funded Status, Net of Tax	7.7	13.4	(2.6)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)	2.2	10	(6.6)
TOTAL COMPREHENSIVE INCOME (LOSS)	371.9	316.3	361.2
Cash Flow Hedges, Tax	(0.5)	(0.2)	(0.2)
Amortization of Pension and OPEB Deferred Costs, Tax	(1)	(0.7)	(0.8)
Pension and OPEB Funded Status, Tax	2	3.6	(0.7)
Indiana Michigan Power Co [Member]
Net Income (Loss)	284.8	269.4	261.3
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax	1.6	1.6	1.6
Amortization of Pension and OPEB Deferred Costs, Net of Tax	(0.1)	(0.2)	0
Pension and OPEB Funded Status, Net of Tax	3.1	0.8	(0.6)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)	4.6	2.2	1
TOTAL COMPREHENSIVE INCOME (LOSS)	289.4	271.6	262.3
Cash Flow Hedges, Tax	0.4	0.4	0.4
Amortization of Pension and OPEB Deferred Costs, Tax	0	0	0
Pension and OPEB Funded Status, Tax	0.8	0.2	(0.2)
Ohio Power Co [Member]
Net Income (Loss)	271.4	297.1	325.5
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax	0	(1)	(1.3)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)		(1)	(1.3)
TOTAL COMPREHENSIVE INCOME (LOSS)	271.4	296.1	324.2
Cash Flow Hedges, Tax	0	(0.3)	(0.4)
Public Service Co Of Oklahoma [Member]
Net Income (Loss)	123	137.6	83.2
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax	(1)	(1)	(1)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)	(1)	(1)	(1)
TOTAL COMPREHENSIVE INCOME (LOSS)	122	136.6	82.2
Cash Flow Hedges, Tax	(0.3)	(0.3)	(0.3)
Southwestern Electric Power Co [Member]
Net Income (Loss)	183.7	162.2	152.2
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax	1.5	1.5	4
Amortization of Pension and OPEB Deferred Costs, Net of Tax	(1.5)	(1.1)	(1.4)
Pension and OPEB Funded Status, Net of Tax	3.2	3.7	(3.1)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)	3.2	4.1	(0.5)
TOTAL COMPREHENSIVE INCOME (LOSS)	186.9	166.3	151.7
Total Comprehensive Income Attributable to Noncontrolling Interest	2.9	3.6	5
TOTAL COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO SHAREHOLDERS	184	162.7	146.7
Cash Flow Hedges, Tax	0.4	0.4	1.1
Amortization of Pension and OPEB Deferred Costs, Tax	(0.4)	(0.3)	(0.4)
Pension and OPEB Funded Status, Tax	$ 0.9	$ 1	$ (0.8)

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				$ 2,589.9															$ 1,816.6									$ 773.3
Common Stock, Dividends, Per Share, Declared		$ 2.53
Beginning 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)
Beginning Balance, Shares at Dec. 31, 2017		512,210,644								512,200,000
Issuance of Common Stock, Value		$ 73.6								$ 8						65.6
Issuance of Common Stock, Shares		1,239,392								1,300,000
Capital Contributions from Member			200	664														200	664
Common Stock Dividends		$ (1,255.5)																							(1,251.1)	[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)
Forward Equity Purchase Contract included in Current and Noncurrent liabilities		23.1														21.8									0																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								513,500,000
Dividends Paid to Member				0	(160)	(124.7)	(337.5)	(50)	(65)
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 Member			200															200
Common Stock Dividends		$ (1,350)																							(1,345.5)	[1]
Common Stock Dividends					(150)	(80)	(85)	(11.3)	(37.5)																				(150)	(80)	(85)	(11.3)	(37.5)
ASU 2018-02 Adoption																																			0
Common Stock Dividends									(3.3)																																(4.5)	(3.3)
Forward Equity Purchase Contract included in Current and Noncurrent liabilities		(7.6)														(9.8)	[2]								47.3																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																																(1.3)	3.6
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
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
Dividends Paid to Member				0	(150)	(80)	(85)	$ (11.3)	(37.5)
TOTAL MEMBER'S EQUITY				4,009.5															2,480.6									1,528.9
Common Stock, Dividends, Per Share, Declared		$ 2.84
Issuance of Common Stock, Value		$ 155								$ 15.9						139.1
Issuance of Common Stock, Shares		2,434,723								2,400,000
Capital Contributions from Member				335				50											335				50
Capital Distribution of Radial Assets to Member				(50)															(50)
Common Stock Dividends		$ (1,424.9)																							(1,415)	[1]
Common Stock Dividends					(200)	(85)	(87.5)																						(200)	(85)	(87.5)
Stockholders Equity ASU 2016-13 Adoption		(1.8)				0.4	0.3	0.3	1.6																(1.8)					0.4	0.3	0.3	1.6
Common Stock Dividends									(1.9)																																(9.9)	(1.9)
Forward Equity Purchase Contract included in Current and Noncurrent liabilities		(86.2)														(85.8)	[3]								110.6																(0.4)
Acquisition																																													$ (43.7)	$ (43.7)
Net Income (Loss)		2,200.1							180.8																2,200.1								180.8
Net Income (Loss) Attributable to Noncontrolling Interests		(3.4)							2.9																																(3.4)	2.9
Net Income (Loss)		2,196.7	241	423.4	369.7	284.8	271.4	123	183.7																		241	423.4	369.7	284.8	271.4	123
Other Comprehensive Income (Loss)		62.6	3.9		2.2	4.6		(1)	3.2																									62.6	3.9	2.2	4.6		(1)	3.2
Ending Balance at Dec. 31, 2020		$ 20,774.5	$ 3,206		4,344.3	2,749.2	2,692.7	$ 1,545.6	2,627.7	$ 3,359.3	$ 260.4	$ 56.6	$ 321.2	$ 157.2	0.1	$ 6,588.9		$ 1,457.9		$ 1,828.7	$ 980.9	$ 838.8	$ 414	812.2	$ 10,687.8		$ 1,757		$ 2,248	$ 1,718.7	$ 1,532.7	$ 974.3	$ 1,811.9	$ (85.1)	$ (8.9)	$ 7.2	$ (7)	$ 0	$ 0.1	$ 1.9	$ 223.6	$ 1.6
Reverse Common Stock Split	[4]								0						$ (135.6)									$ 135.6
Ending Balance, Shares at Dec. 31, 2020		516,808,354						10,482,000		516,800,000
Dividends Paid to Member				(5)	$ (200)	$ (85)	$ (87.5)	$ 0	$ 0																			(5)
TOTAL MEMBER'S EQUITY				$ 4,712.9															$ 2,765.6									$ 1,947.3
[1]	(a)    Cash dividends declared per AEP common share were $2.84, $2.71 and $2.53 for the years ended December 31, 2020, 2019 and 2018, respectively.
[2]	(b)    Includes $(62) million related to a forward equity purchase contract associated with the issuance of Equity Units. See “Equity Units” section of Note 14 for additional information.
[3]	(c)    Includes $(121) million related to a forward equity purchase contract associated with the issuance of Equity Units. See “Equity Units” section of Note 14 for additional information.
[4]	(a) See Note 14 - Financing Activities for additional information.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Current Assets
Cash and Cash Equivalents		$ 392.7	$ 246.8
Restricted Cash		45.6	185.8
Other Temporary Investments		200.8	202.7
Accounts Receivable:
Customers		613.6	625.3
Accrued Unbilled Revenues		248.7	222.4
Pledged Accounts Receivable - AEP Credit		1,018.4	873.9
Miscellaneous		33.1	27.2
Allowance for Uncollectible Accounts		(71.1)	(43.7)
Total Accounts Receivable		1,842.7	1,705.1
Fuel		629.4	528.5
Materials and Supplies		680.6	640.7
Risk Management Assets		94.7	172.8
Accrued Tax Benefits		185.3	85.8
Regulatory Asset for Under-Recovered Fuel Costs		90.7	92.9
Margin Deposits		62	60.4
Prepayments and Other Current Assets		127	156.3
TOTAL CURRENT ASSETS		4,351.5	4,077.8
Property, Plant and Equipment
Generation		23,133.9	22,762.4
Transmission		27,886.7	24,808.6
Distribution		23,972.1	22,443.4
Other Property, Plant and Equipment		5,294.6	4,811.5
Construction Work in Progress		4,025.7	4,319.8
Total Property, Plant and Equipment		84,313	79,145.7
Accumulated Depreciation and Amortization		20,411.4	19,007.6
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		63,901.6	60,138.1
Other Noncurrent Assets
Regulatory Assets		3,527	3,158.8
Securitized Assets		657	858.1
Spent Nuclear Fuel and Decommissioning Trusts		3,306.7	2,975.7
Goodwill		52.5	52.5
Long-term Risk Management Assets		242.2	266.6
Operating Lease Assets		866.4	957.4
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		3,852.3	3,407.3
TOTAL OTHER NONCURRENT ASSETS		12,504.1	11,676.4
TOTAL ASSETS		80,757.2	75,892.3
Current Liabilities
Accounts Payable		1,709.7	2,085.8
Short-term Debt:
Securitized Debt for Receivables - AEP Credit	[1]	592	710
Other Short-term Debt		1,887.3	2,128.3
Total Short-term Debt		2,479.3	2,838.3
Long-term Debt Due Within One Year		2,086.1	1,598.7
Risk Management Liabilities		78.8	114.3
Customer Deposits		335.6	366.1
Accrued Taxes		1,476.4	1,357.8
Accrued Interest		267.6	243.6
Obligations Under Operating Leases		241.3	234.1
Regulatory Liability for Over-Recovered Fuel Costs		52.6	86.6
Other Current Liabilities		1,199.3	1,373.8
TOTAL CURRENT LIABILITIES		9,926.7	10,299.1
Noncurrent Liabilities
Long-term Debt		28,986.4	25,126.8
Long-term Debt - Affiliated		0	0
Long-term Risk Management Liabilities		232.8	261.8
Deferred Income Taxes		8,240.9	7,588.2
Regulatory Liabilities and Deferred Investment Tax Credits		8,378.7	8,457.6
Asset Retirement Obligations		2,469.2	2,216.6
Employee Benefits and Pension Obligations		336.4	466
Obligations Under Operating Leases		638.4	734.6
Deferred Credits and Other Noncurrent Liabilities		728	719.8
TOTAL NONCURRENT LIABILITIES		50,010.8	45,571.4
TOTAL LIABILITIES		59,937.5	55,870.5
Rate Matters
Commitments and Contingencies
Redeemable Noncontrolling Interest		0	65.7
Contingently Redeemable Performance Share Awards		45.2	42.9
Total Mezzanine Equity		45.2	108.6
Equity
Common Stock		3,359.3	3,343.4
Paid-in Capital		6,588.9	6,535.6
Retained Earnings		10,687.8	9,900.9
Accumulated Other Comprehensive Income (Loss)		(85.1)	(147.7)
TOTAL COMMON SHAREHOLDERS' EQUITY		20,550.9	19,632.2
Noncontrolling Interests		223.6	281
TOTAL EQUITY		20,774.5	19,913.2
TOTAL LIABILITIES AND EQUITY		$ 80,757.2	$ 75,892.3
Common Stock, Par Value Per Share		$ 6.50	$ 6.50
Common Stock, Shares, Issued		516,808,354	514,373,631
Common Stock, Shares Authorized		600,000,000	600,000,000
Treasury Stock, Shares		20,204,160	20,204,160
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax		$ 1.8	$ (21.1)
Amortization of Pension and OPEB Deferred Costs, Tax		(1.9)	(1.5)
Pension and OPEB Funded Status, Tax		16.7	15.3
Subsidiaries [Member]
Current Assets
Restricted Cash		45.6	185.8
Other Temporary Investments		194.6	187.8
Short-term Debt:
Long-term Debt Due Within One Year		198.3	565.1
Noncurrent Liabilities
Long-term Debt		950.1	907
AEP Texas Inc. [Member]
Current Assets
Cash and Cash Equivalents		0.1	3.1
Restricted Cash		28.7	154.7
Advances to Affiliates		7.1	207.2
Accounts Receivable:
Customers		112.8	116
Affiliated Companies		5.1	10.1
Accrued Unbilled Revenues		65.8	68.8
Miscellaneous		0	0.3
Allowance for Uncollectible Accounts		(0.1)	(1.8)
Total Accounts Receivable		183.6	193.4
Fuel		0	5.9
Materials and Supplies		70	56.7
Accrued Tax Benefits		16.8	66.1
Prepayments and Other Current Assets		4.6	5.8
TOTAL CURRENT ASSETS		310.9	692.9
Property, Plant and Equipment
Generation		0	351.7
Transmission		5,279.6	4,466.5
Distribution		4,580.8	4,215.2
Other Property, Plant and Equipment		868.4	805.9
Construction Work in Progress		614.1	763.9
Total Property, Plant and Equipment		11,342.9	10,603.2
Accumulated Depreciation and Amortization		1,529.3	1,758.1
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		9,813.6	8,845.1
Other Noncurrent Assets
Regulatory Assets		266.8	280.6
Securitized Assets		446.8	623.4
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		192.1	147.1
TOTAL OTHER NONCURRENT ASSETS		905.7	1,051.1
TOTAL ASSETS		11,030.2	10,589.1
Current Liabilities
Advances from Affiliates		67.1	0
Accounts Payable		231.7	256.8
Affiliated Companies		44	35.6
Short-term Debt:
Long-term Debt Due Within One Year		88.7	392.1
Accrued Taxes		78.3	84.9
Accrued Interest		43.9	35.7
Oklaunion Purchase Power Agreement		0	22.1
Obligations Under Operating Leases		14.5	12
Accumulated Provisions For Rate Refunds		20.1	64.7
Other Current Liabilities		88.5	123.3
TOTAL CURRENT LIABILITIES		676.8	1,027.2
Noncurrent Liabilities
Long-term Debt		4,731.7	4,166.3
Deferred Income Taxes		1,016.7	965.4
Regulatory Liabilities and Deferred Investment Tax Credits		1,270.8	1,316.9
Obligations Under Operating Leases		71	71.1
Deferred Credits and Other Noncurrent Liabilities		57.2	81.1
TOTAL NONCURRENT LIABILITIES		7,147.4	6,600.8
TOTAL LIABILITIES		7,824.2	7,628
Rate Matters
Commitments and Contingencies
Equity
Paid-in Capital		1,457.9	1,457.9
Retained Earnings		1,757	1,516
Accumulated Other Comprehensive Income (Loss)		(8.9)	(12.8)
TOTAL EQUITY		3,206	2,961.1
TOTAL LIABILITIES AND EQUITY		11,030.2	10,589.1
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax		0.3	0.3
Amortization of Pension and OPEB Deferred Costs, Tax		0	0
Pension and OPEB Funded Status, Tax		0.7	0.3
AEP Texas Inc. [Member] | AEP Texas Transition and Restoration Funding [Member]
Current Assets
Restricted Cash		28.7	154.7
Other Noncurrent Assets
Securitized Assets		446.8	621.2
Short-term Debt:
Long-term Debt Due Within One Year		88.7	281.4
Accrued Interest		2.5	7.5
Noncurrent Liabilities
Long-term Debt		403.9	495.4
AEP Transmission Co [Member]
Current Assets
Cash and Cash Equivalents		0	0
Advances to Affiliates		109.1	85.4
Accounts Receivable:
Customers		22.9	19
Affiliated Companies		81.2	66.1
Total Accounts Receivable		104.1	85.1
Materials and Supplies		8.5	13.8
Accrued Tax Benefits		9.9	9.3
Prepayments and Other Current Assets		4.2	3.8
TOTAL CURRENT ASSETS		235.8	197.4
Property, Plant and Equipment
Transmission		9,593.5	8,137.9
Other Property, Plant and Equipment		329.5	269.6
Construction Work in Progress		1,422.6	1,485.7
Total Property, Plant and Equipment		11,345.6	9,893.2
Accumulated Depreciation and Amortization		572.8	402.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		10,772.8	9,490.9
Other Noncurrent Assets
Regulatory Assets		15.1	4.2
Deferred Property Taxes		220.1	193.5
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		2.2	4.8
TOTAL OTHER NONCURRENT ASSETS		237.4	202.5
TOTAL ASSETS		11,246	9,890.8
Current Liabilities
Advances from Affiliates		156.7	137
Accounts Payable		380.4	493.4
Affiliated Companies		97.3	71.2
Short-term Debt:
Long-term Debt Due Within One Year		50	0
Accrued Taxes		418.1	355.6
Accrued Interest		23.9	19.2
Obligations Under Operating Leases		1.2	2.1
Other Current Liabilities		9.9	14.6
TOTAL CURRENT LIABILITIES		1,137.5	1,093.1
Noncurrent Liabilities
Long-term Debt		3,898.5	3,427.3
Deferred Income Taxes		906.9	817.8
Regulatory Liabilities and Deferred Investment Tax Credits		581.8	540.9
Obligations Under Operating Leases		0.4	1.9
Deferred Credits and Other Noncurrent Liabilities		8	0.3
TOTAL NONCURRENT LIABILITIES		5,395.6	4,788.2
TOTAL LIABILITIES		6,533.1	5,881.3
Rate Matters
Commitments and Contingencies
Equity
Members' Capital		2,765.6	2,480.6
Retained Earnings		1,947.3	1,528.9
TOTAL MEMBER'S EQUITY		4,712.9	4,009.5
TOTAL LIABILITIES AND EQUITY		11,246	9,890.8
Appalachian Power Co [Member]
Current Assets
Cash and Cash Equivalents		5.8	3.3
Restricted Cash		16.9	23.5
Advances to Affiliates		21.4	22.1
Accounts Receivable:
Customers		142.8	129
Affiliated Companies		64.3	64.3
Accrued Unbilled Revenues		80.1	59.7
Miscellaneous		0.3	0.5
Allowance for Uncollectible Accounts		(3.1)	(2.6)
Total Accounts Receivable		284.4	250.9
Fuel		193.6	149.7
Materials and Supplies		99.6	105.2
Risk Management Assets		22.4	39.4
Regulatory Asset for Under-Recovered Fuel Costs		5.3	42.5
Prepayments and Other Current Assets		24.7	64
TOTAL CURRENT ASSETS		674.1	700.6
Property, Plant and Equipment
Generation		6,633.7	6,563.7
Transmission		3,900.5	3,584.1
Distribution		4,464.3	4,201.7
Other Property, Plant and Equipment		627.2	571.3
Construction Work in Progress		484.6	593.4
Total Property, Plant and Equipment		16,110.3	15,514.2
Accumulated Depreciation and Amortization		4,716.2	4,432.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		11,394.1	11,081.9
Other Noncurrent Assets
Regulatory Assets		686.3	457.2
Securitized Assets		210.1	234.7
Employee Benefits and Pension Assets		150.1	92
Operating Lease Assets		78.8	78.5
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		121.7	123.4
TOTAL OTHER NONCURRENT ASSETS		1,247	985.8
TOTAL ASSETS		13,315.2	12,768.3
Current Liabilities
Advances from Affiliates		18.6	236.7
Accounts Payable		212	307.8
Affiliated Companies		97.1	92.5
Short-term Debt:
Long-term Debt Due Within One Year		518.3	215.6
Risk Management Liabilities		4.6	1.9
Customer Deposits		77.8	85.8
Accrued Taxes		109.9	99.6
Obligations Under Operating Leases		14.9	15.2
Other Current Liabilities		164.5	170.9
TOTAL CURRENT LIABILITIES		1,217.7	1,226
Noncurrent Liabilities
Long-term Debt		4,315.8	4,148.2
Deferred Income Taxes		1,749.9	1,680.8
Regulatory Liabilities and Deferred Investment Tax Credits		1,224.7	1,268.7
Asset Retirement Obligations		304.8	102.1
Employee Benefits and Pension Obligations		44	50.9
Obligations Under Operating Leases		64.4	64
Deferred Credits and Other Noncurrent Liabilities		49.6	55.2
TOTAL NONCURRENT LIABILITIES		7,753.2	7,369.9
TOTAL LIABILITIES		8,970.9	8,595.9
Rate Matters
Commitments and Contingencies
Equity
Common Stock		260.4	260.4
Paid-in Capital		1,828.7	1,828.7
Retained Earnings		2,248	2,078.3
Accumulated Other Comprehensive Income (Loss)		7.2	5
TOTAL EQUITY		4,344.3	4,172.4
TOTAL LIABILITIES AND EQUITY		$ 13,315.2	$ 12,768.3
Common Stock, No Par Value		$ 0	$ 0
Common Stock, Shares Authorized		30,000,000	30,000,000
Common Stock, Shares Outstanding		13,499,500	13,499,500
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax		$ (0.5)	$ (0.2)
Amortization of Pension and OPEB Deferred Costs, Tax		(1)	(0.7)
Pension and OPEB Funded Status, Tax		2	3.6
Indiana Michigan Power Co [Member]
Current Assets
Cash and Cash Equivalents		3.3	2
Advances to Affiliates		13.3	13.2
Accounts Receivable:
Customers		44	53.6
Affiliated Companies		51.3	53.7
Accrued Unbilled Revenues		0	2.5
Miscellaneous		2	0.3
Allowance for Uncollectible Accounts		(0.3)	(0.6)
Total Accounts Receivable		97	109.5
Fuel		86	56.2
Materials and Supplies		175.8	171.3
Risk Management Assets		3.6	9.8
Accrued Tax Benefits		10.3	0
Regulatory Asset for Under-Recovered Fuel Costs		5.4	3
Accrued Reimbursement of Spent Nuclear Fuel Costs		14.2	24
Prepayments and Other Current Assets		9.9	14
TOTAL CURRENT ASSETS		418.8	403
Property, Plant and Equipment
Generation		5,264.7	5,099.7
Transmission		1,696.4	1,641.8
Distribution		2,594.6	2,437.6
Other Property, Plant and Equipment		686.7	632.6
Construction Work in Progress		362.4	382.3
Total Property, Plant and Equipment		10,604.8	10,194
Accumulated Depreciation and Amortization		3,552.5	3,294.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		7,052.3	6,899.7
Other Noncurrent Assets
Regulatory Assets		404.8	482.1
Spent Nuclear Fuel and Decommissioning Trusts		3,306.7	2,975.7
Operating Lease Assets		218.1	294.9
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		237.6	182
TOTAL OTHER NONCURRENT ASSETS		4,167.2	3,934.7
TOTAL ASSETS		11,638.3	11,237.4
Current Liabilities
Advances from Affiliates		103	114.4
Accounts Payable		153.2	169.4
Affiliated Companies		80.5	68.4
Short-term Debt:
Long-term Debt Due Within One Year		369.6	139.7
Customer Deposits		41.7	39.4
Accrued Taxes		102.5	112.4
Accrued Interest		35.6	36.2
Obligations Under Operating Leases		85.6	87.3
Regulatory Liability for Over-Recovered Fuel Costs		20.8	6.1
Other Current Liabilities		112	110.1
TOTAL CURRENT LIABILITIES		1,104.5	883.4
Noncurrent Liabilities
Long-term Debt		2,660.3	2,910.5
Deferred Income Taxes		1,064.4	979.7
Regulatory Liabilities and Deferred Investment Tax Credits		2,041.9	1,891.4
Asset Retirement Obligations		1,812.9	1,748.6
Obligations Under Operating Leases		135.9	211.6
Deferred Credits and Other Noncurrent Liabilities		69.2	67.8
TOTAL NONCURRENT LIABILITIES		7,784.6	7,809.6
TOTAL LIABILITIES		8,889.1	8,693
Rate Matters
Commitments and Contingencies
Equity
Common Stock		56.6	56.6
Paid-in Capital		980.9	980.9
Retained Earnings		1,718.7	1,518.5
Accumulated Other Comprehensive Income (Loss)		(7)	(11.6)
TOTAL EQUITY		2,749.2	2,544.4
TOTAL LIABILITIES AND EQUITY		$ 11,638.3	$ 11,237.4
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
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax		$ 0.4	$ 0.4
Amortization of Pension and OPEB Deferred Costs, Tax		0	0
Pension and OPEB Funded Status, Tax		0.8	0.2
Indiana Michigan Power Co [Member] | DCC Fuel [Member]
Short-term Debt:
Long-term Debt Due Within One Year		75.7	86.1
Ohio Power Co [Member]
Current Assets
Cash and Cash Equivalents		7.4	3.7
Accounts Receivable:
Customers		50	53
Affiliated Companies		65.1	59.3
Accrued Unbilled Revenues		14.8	20.3
Miscellaneous		3.9	0.5
Allowance for Uncollectible Accounts		(0.6)	(0.7)
Total Accounts Receivable		133.2	132.4
Materials and Supplies		66.9	52.3
Renewable Energy Credits		29.5	30.9
Prepayments and Other Current Assets		19.3	19.2
TOTAL CURRENT ASSETS		256.3	238.5
Property, Plant and Equipment
Transmission		2,831.9	2,686.3
Distribution		5,708.3	5,323.5
Other Property, Plant and Equipment		899.6	765.8
Construction Work in Progress		362.3	394.4
Total Property, Plant and Equipment		9,802.1	9,170
Accumulated Depreciation and Amortization		2,350	2,263
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		7,452.1	6,907
Other Noncurrent Assets
Regulatory Assets		385.8	351.8
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		616.2	546.3
TOTAL OTHER NONCURRENT ASSETS		1,002	898.1
TOTAL ASSETS		8,710.4	8,043.6
Current Liabilities
Advances from Affiliates		259.2	131
Accounts Payable		181	233.7
Affiliated Companies		118.4	103.6
Short-term Debt:
Long-term Debt Due Within One Year		500.1	0.1
Risk Management Liabilities		8.7	7.3
Customer Deposits		55.1	70.6
Accrued Taxes		631	587.9
Obligations Under Operating Leases		13.1	12.5
Regulatory Liability for Over-Recovered Fuel Costs		3.9	2.8
Other Current Liabilities		139.6	151.2
TOTAL CURRENT LIABILITIES		1,906.2	1,297.9
Noncurrent Liabilities
Long-term Debt		1,930.1	2,081.9
Long-term Risk Management Liabilities		101.6	96.3
Deferred Income Taxes		955.1	849.4
Regulatory Liabilities and Deferred Investment Tax Credits		1,005.2	1,090.9
Obligations Under Operating Leases		79.5	76
Deferred Credits and Other Noncurrent Liabilities		40	42.7
TOTAL NONCURRENT LIABILITIES		4,111.5	4,237.2
TOTAL LIABILITIES		6,017.7	5,535.1
Rate Matters
Commitments and Contingencies
Equity
Common Stock		321.2	321.2
Paid-in Capital		838.8	838.8
Retained Earnings		1,532.7	1,348.5
TOTAL EQUITY		2,692.7	2,508.5
TOTAL LIABILITIES AND EQUITY		$ 8,710.4	$ 8,043.6
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
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax		$ 0	$ (0.3)
Public Service Co Of Oklahoma [Member]
Current Assets
Cash and Cash Equivalents		2.6	1.5
Advances to Affiliates		0	38.8
Accounts Receivable:
Customers		30.8	28.9
Affiliated Companies		15.6	20.6
Miscellaneous		2	0.6
Allowance for Uncollectible Accounts		0	(0.3)
Total Accounts Receivable		48.4	49.8
Fuel		17.9	12.2
Materials and Supplies		54	46.8
Risk Management Assets		10.3	15.8
Accrued Tax Benefits		10.9	11.3
Regulatory Asset for Under-Recovered Fuel Costs		30.1	0
Prepayments and Other Current Assets		7.1	12
TOTAL CURRENT ASSETS		181.3	188.2
Property, Plant and Equipment
Generation		1,480.7	1,574.6
Transmission		1,069.9	948.5
Distribution		2,853	2,684.8
Other Property, Plant and Equipment		393.3	342.1
Construction Work in Progress		128.7	133.4
Total Property, Plant and Equipment		5,925.6	5,683.4
Accumulated Depreciation and Amortization		1,605.6	1,580.1
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		4,320	4,103.3
Other Noncurrent Assets
Regulatory Assets		375	375.2
Employee Benefits and Pension Assets		65.8	43.9
Operating Lease Assets		42.6	36.8
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		6	4.1
TOTAL OTHER NONCURRENT ASSETS		489.4	460
TOTAL ASSETS		4,990.7	4,751.5
Current Liabilities
Advances from Affiliates		155.4	0
Accounts Payable		107	134.3
Affiliated Companies		43.4	59.3
Short-term Debt:
Long-term Debt Due Within One Year		0.5	13.2
Customer Deposits		54.8	58.9
Accrued Taxes		26.8	22.9
Obligations Under Operating Leases		6.5	5.8
Regulatory Liability for Over-Recovered Fuel Costs		0	63.9
Other Current Liabilities		84.2	87.5
TOTAL CURRENT LIABILITIES		478.6	445.8
Noncurrent Liabilities
Long-term Debt		1,373.3	1,373
Deferred Income Taxes		688.5	628.3
Regulatory Liabilities and Deferred Investment Tax Credits		802.2	837.2
Asset Retirement Obligations		45.7	44.5
Obligations Under Operating Leases		36.2	31
Deferred Credits and Other Noncurrent Liabilities		20.6	18.4
TOTAL NONCURRENT LIABILITIES		2,966.5	2,932.4
TOTAL LIABILITIES		3,445.1	3,378.2
Rate Matters
Commitments and Contingencies
Equity
Common Stock		157.2	157.2
Paid-in Capital		414	364
Retained Earnings		974.3	851
Accumulated Other Comprehensive Income (Loss)		0.1	1.1
TOTAL EQUITY		1,545.6	1,373.3
TOTAL LIABILITIES AND EQUITY		$ 4,990.7	$ 4,751.5
Common Stock, Par Value Per Share		$ 15	$ 15
Common Stock, Shares, Issued		10,482,000	10,482,000
Common Stock, Shares Authorized		11,000,000	11,000,000
Common Stock, Shares Outstanding		9,013,000	9,013,000
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax		$ (0.3)	$ (0.3)
Southwestern Electric Power Co [Member]
Current Assets
Cash and Cash Equivalents		13.2	1.6
Advances to Affiliates		2.1	2.1
Accounts Receivable:
Customers		27.1	29
Affiliated Companies		25.1	34.5
Miscellaneous		12.7	13.5
Allowance for Uncollectible Accounts		0	(1.7)
Total Accounts Receivable		64.9	75.3
Fuel		191.1	140.1
Materials and Supplies		95.8	94
Risk Management Assets		3.2	6.4
Accrued Tax Benefits		29.9	7.6
Regulatory Asset for Under-Recovered Fuel Costs		2.6	4.9
Prepayments and Other Current Assets		25.2	22.1
TOTAL CURRENT ASSETS		428	354.1
Property, Plant and Equipment
Generation		4,681.4	4,691.4
Transmission		2,165.7	2,056.5
Distribution		2,382.5	2,270.7
Other Property, Plant and Equipment		788.8	733.4
Construction Work in Progress		228.3	216.9
Total Property, Plant and Equipment		10,246.7	9,968.9
Accumulated Depreciation and Amortization		3,158.5	2,873.7
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		7,088.2	7,095.2
Other Noncurrent Assets
Regulatory Assets		403.1	222.4
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		234.8	160.5
TOTAL OTHER NONCURRENT ASSETS		637.9	382.9
TOTAL ASSETS		8,154.1	7,832.2
Current Liabilities
Advances from Affiliates		124.6	59.9
Accounts Payable		135.9	138
Affiliated Companies		43	53.6
Short-term Debt:
Other Short-term Debt		35	18.3
Long-term Debt Due Within One Year		106.2	121.2
Risk Management Liabilities		0.7	1.9
Customer Deposits		61.3	65
Accrued Taxes		41	41.8
Accrued Interest		34.6	34.6
Obligations Under Operating Leases		7.9	6.5
Regulatory Liability for Over-Recovered Fuel Costs		37.6	13.6
Other Current Liabilities		173.4	133.9
TOTAL CURRENT LIABILITIES		763.6	674.7
Noncurrent Liabilities
Long-term Debt		2,530.2	2,534.4
Long-term Risk Management Liabilities		1	3.1
Deferred Income Taxes		1,017.6	940.9
Regulatory Liabilities and Deferred Investment Tax Credits		863.4	892.3
Asset Retirement Obligations		193.7	196.7
Employee Benefits and Pension Obligations		18.6	28.1
Obligations Under Operating Leases		44.1	34.7
Deferred Credits and Other Noncurrent Liabilities		94.2	86.2
TOTAL NONCURRENT LIABILITIES		4,762.8	4,716.4
TOTAL LIABILITIES		5,526.4	5,391.1
Rate Matters
Commitments and Contingencies
Equity
Common Stock		0.1	135.7
Paid-in Capital		812.2	676.6
Retained Earnings		1,811.9	1,629.5
Accumulated Other Comprehensive Income (Loss)		1.9	(1.3)
TOTAL COMMON SHAREHOLDERS' EQUITY		2,626.1	2,440.5
Noncontrolling Interests		1.6	0.6
TOTAL EQUITY		2,627.7	2,441.1
TOTAL LIABILITIES AND EQUITY		$ 8,154.1	$ 7,832.2
Common Stock, Par Value Per Share		$ 18	$ 18
Common Stock, Shares Authorized		3,680	3,680
Common Stock, Shares Outstanding		3,680	3,680
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax		$ 0.4	$ 0.4
Amortization of Pension and OPEB Deferred Costs, Tax		(0.4)	(0.3)
Pension and OPEB Funded Status, Tax		0.9	1
Southwestern Electric Power Co [Member] | Sabine Mining Co [Member]
Current Assets
Cash and Cash Equivalents		10.1	0
Accounts Receivable:
Fuel		35.2	47
Materials and Supplies		23.3	23.1
Property, Plant and Equipment
Other Property, Plant and Equipment		223.7	212.3
Accumulated Depreciation and Amortization		$ 126.5	$ 107.5
[1]	Amount of securitized debt for receivables as accounted for under the “Transfers and Servicing” accounting guidance.

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Activites
Net Income (Loss)	$ 2,196.7	$ 1,919.8	$ 1,931.3
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	2,682.8	2,514.5	2,286.6
Rockport Plant, Unit 2 Operating Lease Amortization	136.5	136.5	0
Deferred Income Taxes	196.1	(17.8)	104.3
Asset Impairments and Other Related Charges	0	156.4	70.6
Allowance for Equity Funds Used During Construction	(148.1)	(168.4)	(132.5)
Mark-to-Market of Risk Management Contracts	66.5	(29.2)	(66.4)
Amortization of Nuclear Fuel	87.5	89.1	113.8
Pension and Postemployment Benefit Reserves	(8.5)	(24.6)	(42.8)
Pension Contributions to Qualified Plan Trust	(110.3)	0	0
Property Taxes	(43.3)	(73.8)	(59.1)
Deferred Fuel Over/Under-Recovery, Net	(31.8)	85.2	189.7
Change in Regulatory Assets	(337.9)	49.5	354.1
Change in Other Noncurrent Assets	(142.5)	(112.8)	(172.1)
Change in Other Noncurrent Liabilities	(54.5)	(116.1)	129
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(129.3)	247.8	145.9
Fuel, Materials and Supplies	(142.9)	(248.2)	20.7
Accounts Payable	(35.3)	5.8	36.6
Accrued Taxes, Net	20.1	138.9	153.2
Rockport Plant, Unit 2 Operating Lease Payments	(147.7)	(147.7)	0
Other Current Assets	34.3	70.7	10.5
Other Current Liabilities	(255.5)	(205.5)	149.8
Net Cash Flows from Operating Activities	3,832.9	4,270.1	5,223.2
Investing Activities
Construction Expenditures	(6,246.3)	(6,051.4)	(6,310.9)
Purchases of Investment Securities	(1,678.8)	(1,576)	(2,067.8)
Sales of Investment Securities	1,644.3	1,494.2	2,010
Acquisitions of Nuclear Fuel	(69.7)	(92.3)	(46.1)
Acquisition of Assets	0	(918.4)	0
Other Investing Activities	116.6	(0.6)	61.2
Net Cash Flows Used for Investing Activities	(6,233.9)	(7,144.5)	(6,353.6)
Financing Activities
Issuance of Common Stock, Net	155	65.3	73.6
Issuance of Long-term Debt	5,626.1	4,536.6	4,945.7
Issuance of Short-term Debt with Original Maturities Greater Than 90 Days	1,396.5	0	205.6
Change in Short-term Debt with Original Maturities Less Than 90 Days, Net	(448.4)	928.3	271.4
Retirement of Long-term Debt	(1,339.8)	(1,220.8)	(2,782)
Redemption of Short-term Debt with Original Maturities Greater Than 90 Days	(1,307.1)	0	(205.6)
Principal Payments for Finance Lease Obligations	(61.7)	(70.7)	(65.1)
Dividends Paid on Common Stock	(1,424.9)	(1,350)	(1,255.5)
Redemption of Noncontrolling Interest	(100.2)	0	0
Other Financing Activities	(88.8)	(25.8)	(26.2)
Net Cash Flows from Financing Activities	2,406.7	2,862.9	1,161.9
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	5.7	(11.5)	31.5
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	432.6	444.1	412.6
Cash and Cash Equivalents at Beginning of Period	246.8
Cash, Cash Equivalents and Restricted Cash at End of Period	438.3	432.6	444.1
Cash and Cash Equivalents at End of Period	392.7	246.8
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	1,029.1	1,022.5	939.3
Net Cash Paid (Received) for Income Taxes	(49.1)	6.1	(24.7)
Construction Expenditures Included in Current Liabilities as of December 31,	975.4	1,341.1	1,120.4
Acquisition of Nuclear Fuel Included in Current Liabilities as of December 31,	33.4	0.1	4
Expected Reimbursement For Spent Nuclear Fuel Dry Cask Storage	2.6	0.3	2.2
Noncash Increase in Advances to Affiliates, Net due to Contribution of Mutual Energy SWEPCo, LLC	0	0	84
AEP Texas Inc. [Member]
Operating Activites
Net Income (Loss)	241	178.3	211.3
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	529.8	622.3	499.6
Deferred Income Taxes	(15.2)	(23.5)	(16.5)
Asset Impairments and Other Related Charges	0	32.5	0
Allowance for Equity Funds Used During Construction	(19.4)	(15.2)	(20)
Mark-to-Market of Risk Management Contracts	0	(0.2)	0.7
Pension Contributions to Qualified Plan Trust	(11.3)	0	0
Change in Other Noncurrent Assets	(74)	9.3	(60.3)
Change in Other Noncurrent Liabilities	(24.7)	11.3	44.9
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	9.8	3.5	(2.9)
Fuel, Materials and Supplies	(7.4)	(1)	(6)
Accounts Payable	30.2	7.5	(20.3)
Accrued Taxes, Net	42.7	(11.8)	(5.6)
Other Current Assets	0.8	(0.4)	0.8
Other Current Liabilities	(88.1)	10.8	26.2
Net Cash Flows from Operating Activities	614.2	823.4	651.9
Investing Activities
Construction Expenditures	(1,295)	(1,275.1)	(1,428.8)
Change in Advances to Affiliates, Net	200.1	(199.2)	103.9
Other Investing Activities	29.5	2.1	35.2
Net Cash Flows Used for Investing Activities	(1,065.4)	(1,472.2)	(1,289.7)
Financing Activities
Capital Contributions from Member	0	200	200
Issuance of Long-term Debt	652.7	1,070.4	494
Change in Advances from Affiliates, Net	67.1	(216)	216
Retirement of Long-term Debt	(392.1)	(401.8)	(266.1)
Principal Payments for Finance Lease Obligations	(6.3)	(5.1)	(4.7)
Other Financing Activities	0.8	(0.7)	1.2
Net Cash Flows from Financing Activities	322.2	646.8	640.4
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	(129)	(2)	2.6
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	157.8	159.8	157.2
Cash and Cash Equivalents at Beginning of Period	3.1
Cash, Cash Equivalents and Restricted Cash at End of Period	28.8	157.8	159.8
Cash and Cash Equivalents at End of Period	0.1	3.1
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	153.2	148.6	145.9
Net Cash Paid (Received) for Income Taxes	(42.9)	(11)	7.9
Noncash Acquisitions Under Finance Leases	5.6	11.4	10.6
Construction Expenditures Included in Current Liabilities as of December 31,	177.8	225.5	243.1
AEP Transmission Co [Member]
Operating Activites
Net Income (Loss)	423.4	439.7	315.9
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	249	176	133.9
Deferred Income Taxes	81.6	91.3	98.9
Allowance for Equity Funds Used During Construction	(74)	(84.3)	(70.6)
Property Taxes	(26.6)	(35.6)	(32.9)
Change in Other Noncurrent Assets	(8.2)	9.6	14.6
Change in Other Noncurrent Liabilities	8.3	(8.1)	17.4
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(19)	(5.4)	36.7
Fuel, Materials and Supplies	5.3	5.2	(5.4)
Accounts Payable	77.8	37.6	(7.5)
Accrued Taxes, Net	62.7	90.8	73.4
Accrued Interest	4.7	3.3	0.9
Other Current Assets	0.7	(0.3)	(0.3)
Other Current Liabilities	(14.5)	(11.2)	(26.4)
Net Cash Flows from Operating Activities	771.2	708.6	548.6
Investing Activities
Construction Expenditures	(1,615.9)	(1,410.1)	(1,526.4)
Change in Advances to Affiliates, Net	(23.7)	11.5	49.4
Acquisition of Assets	(6)	(9.4)	(37.4)
Other Investing Activities	5.2	4.8	1.1
Net Cash Flows Used for Investing Activities	(1,640.4)	(1,403.2)	(1,513.3)
Financing Activities
Capital Contributions from Member	335	0	664
Issuance of Long-term Debt	519.5	688	321
Change in Advances from Affiliates, Net	19.7	91.6	29.7
Retirement of Long-term Debt	0	(85)	(50)
Principal Payments for Finance Lease Obligations	0	0
Dividends Paid to Member	(5)	0	0
Net Cash Flows from Financing Activities	869.2	694.6	964.7
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	119.7	90.6	80.2
Net Cash Paid (Received) for Income Taxes	22.9	1.5	(30.7)
Construction Expenditures Included in Current Liabilities as of December 31,	311.9	472.7	345
Noncash Distribution of Radial Assets to Member	(50)	0	0
Appalachian Power Co [Member]
Operating Activites
Net Income (Loss)	369.7	306.3	367.8
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	507.5	466.8	428.4
Deferred Income Taxes	(26.2)	(126.2)	(16.8)
Asset Impairments and Other Related Charges	0	92.9	0
Carrying Costs Income	0	0	(1.3)
Allowance for Equity Funds Used During Construction	(14.6)	(16.6)	(13.2)
Mark-to-Market of Risk Management Contracts	18.8	19.9	(33)
Pension Contributions to Qualified Plan Trust	(7)	0	0
Deferred Fuel Over/Under-Recovery, Net	37.2	57.1	(10.8)
Re-Establishment of Regulatory Asset - Coal Fired Generation	(49)	0	0
Change in Other Noncurrent Assets	(40.4)	(38.2)	58.1
Change in Other Noncurrent Liabilities	11.2	(40.3)	(4.8)
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(30.2)	35.7	33.6
Fuel, Materials and Supplies	(38.2)	(93.4)	27.8
Accounts Payable	(48.1)	37.7	(13.3)
Accrued Taxes, Net	31.3	(10.2)	(13.2)
Other Current Assets	18.3	15.4	(6.1)
Other Current Liabilities	(28.3)	(45.5)	42.1
Net Cash Flows from Operating Activities	712	661.4	846.6
Investing Activities
Construction Expenditures	(767.4)	(862.6)	(780.7)
Change in Advances to Affiliates, Net	0.7	0.9	0.5
Other Investing Activities	8.8	24.3	10.8
Net Cash Flows Used for Investing Activities	(757.9)	(837.4)	(769.4)
Financing Activities
Issuance of Long-term Debt	606.9	478.2	203.2
Change in Advances from Affiliates, Net	(218.1)	31.1	19.6
Retirement of Long-term Debt	(140.3)	(180.5)	(124)
Principal Payments for Finance Lease Obligations	(7.4)	(6.7)	(6.9)
Dividends Paid to Member	(200)	(150)	(160)
Other Financing Activities	0.7	0.9	1.5
Net Cash Flows from Financing Activities	41.8	173	(66.6)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	(4.1)	(3)	10.6
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	26.8	29.8	19.2
Cash and Cash Equivalents at Beginning of Period	3.3
Cash, Cash Equivalents and Restricted Cash at End of Period	22.7	26.8	29.8
Cash and Cash Equivalents at End of Period	5.8	3.3
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	207.1	190.7	182
Net Cash Paid (Received) for Income Taxes	0	63	(13)
Noncash Acquisitions Under Finance Leases	7.2	8.8	5.5
Construction Expenditures Included in Current Liabilities as of December 31,	105.6	149.7	134.4
Indiana Michigan Power Co [Member]
Operating Activites
Net Income (Loss)	284.8	269.4	261.3
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	411.6	350.6	293.1
Rockport Plant, Unit 2 Operating Lease Amortization	69.2	69.2	0
Deferred Income Taxes	(16.2)	(52.7)	(42.9)
Amortization (Deferral) of Incremental Nuclear Refueling Outage Expenses, Net	24.4	(26.4)	29.2
Allowance for Equity Funds Used During Construction	(11.5)	(19.4)	(11.9)
Mark-to-Market of Risk Management Contracts	5.9	(0.6)	(4.1)
Amortization of Nuclear Fuel	87.5	89.1	113.8
Pension Contributions to Qualified Plan Trust	(6.4)	0	0
Deferred Fuel Over/Under-Recovery, Net	12.4	(24.3)	39.7
Change in Other Noncurrent Assets	6.1	8.3	(36.5)
Change in Other Noncurrent Liabilities	45	33.7	72.1
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	14.5	35.4	4.8
Fuel, Materials and Supplies	(34.7)	(22.4)	(11.2)
Accounts Payable	(10.8)	3.6	(14.1)
Accrued Taxes, Net	(20.2)	48.3	41.2
Rockport Plant, Unit 2 Operating Lease Payments	(73.9)	(73.9)	0
Other Current Assets	14.3	11.2	1.5
Other Current Liabilities	(25.7)	(13.9)	(10.3)
Net Cash Flows from Operating Activities	776.3	685.2	725.7
Investing Activities
Construction Expenditures	(544.7)	(585.9)	(568.5)
Change in Advances to Affiliates, Net	(0.1)	(0.5)	(0.3)
Purchases of Investment Securities	(1,637.2)	(1,531)	(2,064.7)
Sales of Investment Securities	1,593.4	1,473	2,010
Acquisitions of Nuclear Fuel	(69.7)	(92.3)	(46.1)
Other Investing Activities	9.4	16.6	14.8
Net Cash Flows Used for Investing Activities	(648.9)	(720.1)	(654.8)
Financing Activities
Issuance of Long-term Debt	69.5	123.3	1,168.1
Change in Advances from Affiliates, Net	(11.4)	113.3	(210.5)
Retirement of Long-term Debt	(93.2)	(117.1)	(884.9)
Principal Payments for Finance Lease Obligations	(6.5)	(5.7)	(8.8)
Dividends Paid to Member	(85)	(80)	(124.7)
Other Financing Activities	0.5	0.7	(9)
Net Cash Flows from Financing Activities	(126.1)	34.5	(69.8)
Net Increase (Decrease) in Cash and Cash Equivalents	1.3	(0.4)	1.1
Cash and Cash Equivalents at Beginning of Period	2	2.4	1.3
Cash and Cash Equivalents at End of Period	3.3	2	2.4
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	107.6	111.9	116.9
Net Cash Paid (Received) for Income Taxes	42.1	3.4	32.6
Noncash Acquisitions Under Finance Leases	3	11.9	5.8
Construction Expenditures Included in Current Liabilities as of December 31,	62.8	86	93
Acquisition of Nuclear Fuel Included in Current Liabilities as of December 31,	33.4	0.1	4
Expected Reimbursement For Spent Nuclear Fuel Dry Cask Storage	2.6	0.3	2.2
Ohio Power Co [Member]
Operating Activites
Net Income (Loss)	271.4	297.1	325.5
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	276.6	240.9	259.7
Amortization of Generation Deferrals	0	65.3	223.9
Deferred Income Taxes	77.2	43.8	(36.2)
Carrying Costs Income	(1.6)	(1)	(1.7)
Allowance for Equity Funds Used During Construction	(12.5)	(18.2)	(9.8)
Mark-to-Market of Risk Management Contracts	6.7	4	(32.2)
Property Taxes	(16.6)	(33.7)	(12.5)
Refund of Global Settlement	0	(16.5)	(5.5)
Reversal of a Regulatory Provision	0	(56.2)	0
Change in Regulatory Assets	(69.4)	(20.1)	171.5
Change in Other Noncurrent Assets	(49.4)	(35.3)	(11.5)
Change in Other Noncurrent Liabilities	(66.4)	(93.2)	53.8
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	4.2	75	43.1
Fuel, Materials and Supplies	(23.9)	(16.4)	(11.3)
Accounts Payable	10.3	0.4	(13.8)
Accrued Taxes, Net	43.3	38.7	26.8
Other Current Assets	1.9	0.8	8.1
Other Current Liabilities	(42.5)	(55.2)	49.1
Net Cash Flows from Operating Activities	410.9	421.2	1,028.7
Investing Activities
Construction Expenditures	(813.2)	(799.2)	(725.9)
Other Investing Activities	22.2	55.1	18.4
Net Cash Flows Used for Investing Activities	(791)	(744.1)	(707.5)
Financing Activities
Issuance of Long-term Debt	347	444.3	392.8
Change in Advances from Affiliates, Net	128.2	16.9	26.3
Retirement of Long-term Debt	(0.1)	(80.3)	(397.1)
Principal Payments for Finance Lease Obligations	(4.7)	(3.5)	(3.8)
Dividends Paid to Member	(87.5)	(85)	(337.5)
Other Financing Activities	0.9	1.7	0.9
Net Cash Flows from Financing Activities	383.8	294.1	(318.4)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	3.7	(28.8)	2.8
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	3.7	32.5	29.7
Cash and Cash Equivalents at Beginning of Period	3.7
Cash, Cash Equivalents and Restricted Cash at End of Period	7.4	3.7	32.5
Cash and Cash Equivalents at End of Period	7.4	3.7
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	111.2	100.6	97.1
Net Cash Paid (Received) for Income Taxes	(26.9)	7.3	51.3
Noncash Acquisitions Under Finance Leases	6.1	11.3	4.4
Construction Expenditures Included in Current Liabilities as of December 31,	76.7	125.9	98.2
Public Service Co Of Oklahoma [Member]
Operating Activites
Net Income (Loss)	123	137.6	83.2
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	173.5	169.5	164
Deferred Income Taxes	17	(18.2)	(31.1)
Allowance for Equity Funds Used During Construction	(4)	(2.7)	(0.4)
Mark-to-Market of Risk Management Contracts	5.5	(6.4)	(3)
Deferred Fuel Over/Under-Recovery, Net	(94)	43.8	57.4
Change in Other Noncurrent Assets	(17.9)	5.7	0
Change in Other Noncurrent Liabilities	1.6	(7.3)	21.4
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	1.4	15.4	5.1
Fuel, Materials and Supplies	(14.1)	(1.9)	(2.6)
Accounts Payable	(29.5)	7	17.7
Accrued Taxes, Net	3.6	3.9	13.2
Other Current Assets	4.6	(0.7)	(0.8)
Other Current Liabilities	(13.7)	4.6	6.4
Net Cash Flows from Operating Activities	157	350.3	330.5
Investing Activities
Construction Expenditures	(337.9)	(291.9)	(240.2)
Change in Advances to Affiliates, Net	38.8	(38.8)	0
Other Investing Activities	4	2.6	7.2
Net Cash Flows Used for Investing Activities	(295.1)	(328.1)	(233)
Financing Activities
Issuance of Long-term Debt	0	349.5	0
Change in Advances from Affiliates, Net	155.4	(105.5)	(44.1)
Retirement of Long-term Debt	(13.2)	(250.5)	(0.5)
Principal Payments for Finance Lease Obligations	(3.5)	(3.1)	(3.3)
Dividends Paid to Member	0	(11.3)	(50)
Other Financing Activities	0.5	(1.8)	0.8
Net Cash Flows from Financing Activities	139.2	(22.7)	(97.1)
Net Increase (Decrease) in Cash and Cash Equivalents	1.1	(0.5)	0.4
Cash and Cash Equivalents at Beginning of Period	1.5	2	1.6
Cash and Cash Equivalents at End of Period	2.6	1.5	2
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	59.1	61.1	62
Net Cash Paid (Received) for Income Taxes	(11.8)	22.4	17.9
Noncash Acquisitions Under Finance Leases	3.2	5.3	4.3
Construction Expenditures Included in Current Liabilities as of December 31,	35.5	46	33.2
Noncash Contribution of Radial Assets from Parent	50	0	0
Southwestern Electric Power Co [Member]
Operating Activites
Net Income (Loss)	183.7	162.2	152.2
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	272.7	249.1	239.5
Deferred Income Taxes	32.4	(11)	1.2
Allowance for Equity Funds Used During Construction	(7.7)	(6.8)	(6)
Mark-to-Market of Risk Management Contracts	(0.1)	0.8	4
Pension Contributions to Qualified Plan Trust	(8.9)	0	0
Deferred Fuel Over/Under-Recovery, Net	26.3	16.5	(2.4)
Change in Regulatory Assets	(108.4)	3.5	(0.7)
Change in Other Noncurrent Assets	16.1	2.7	(18.1)
Change in Other Noncurrent Liabilities	25.2	2.7	42.8
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	7.3	0	53.5
Fuel, Materials and Supplies	(46.4)	(46.1)	3.5
Accounts Payable	11.1	(28.4)	0.9
Accrued Taxes, Net	(23.1)	(3.2)	2.3
Other Current Assets	(2.8)	(8.9)	15.6
Other Current Liabilities	(21.1)	6.7	16.5
Net Cash Flows from Operating Activities	356.3	339.8	504.8
Investing Activities
Construction Expenditures	(402.7)	(412.7)	(451)
Change in Advances to Affiliates, Net	0	81.3	(81.4)
Proceeds from Sales of Assets	4.4	0.2	1.4
Other Investing Activities	5.7	1	2.1
Net Cash Flows Used for Investing Activities	(392.6)	(330.2)	(528.9)
Financing Activities
Issuance of Long-term Debt	0	0	1,065.7
Change in Short-term Debt with Original Maturities Less Than 90 Days, Net	16.7	18.3	(22)
Change in Advances from Affiliates, Net	64.7	59.9	(118.7)
Retirement of Long-term Debt	(21.2)	(59.7)	(794.5)
Principal Payments for Finance Lease Obligations	(10.9)	(11)	(11.5)
Dividends Paid to Member	0	(37.5)	(65)
Dividends Paid on Common Stock	(1.9)	(3.3)	(4.3)
Other Financing Activities	0.5	0.8	(2.7)
Net Cash Flows from Financing Activities	47.9	(32.5)	47
Net Increase (Decrease) in Cash and Cash Equivalents	11.6	(22.9)	22.9
Cash and Cash Equivalents at Beginning of Period	1.6	24.5	1.6
Cash and Cash Equivalents at End of Period	13.2	1.6	24.5
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	110.7	111.1	125.7
Net Cash Paid (Received) for Income Taxes	4.3	8.6	18.8
Noncash Acquisitions Under Finance Leases	8.9	7.4	3.6
Construction Expenditures Included in Current Liabilities as of December 31,	$ 46	$ 69.1	$ 42

Organization and Summary of Sig

Organization and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
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. 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 non-consolidated affiliates, conducts lignite mining operations to fuel certain of its generation facilities. 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 one active REP 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 assets, the power from which is marketed and sold in ERCOT. Power from the Oklaunion Power Station was also marketed and sold by these nonregulated subsidiaries in ERCOT prior to its retirement in September 2020. 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, TA and TCA, 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 statements of cash flows for OPCo include the Registrant Subsidiary and Ohio Phase-in Recovery Funding (a consolidated VIE) for the years ended December 31, 2019 and 2018. 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, I&M 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. In October 2020, AEP Texas, PSO and a nonaffiliated joint-owner executed an Environmental Liability and Property Transfer and Asset Purchase Agreement with a nonaffiliated third-party related to the Oklaunion Power Station site. See Note 7 – Acquisitions, Dispositions and Impairments 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 and APCo) Restricted Cash primarily includes funds held by trustees for the payment of securitization bonds. 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, 2020 AEP AEP Texas APCo (in millions) Cash and Cash Equivalents $ 392.7 $ 0.1 $ 5.8 Restricted Cash 45.6 28.7 16.9 Total Cash, Cash Equivalents and Restricted Cash $ 438.3 $ 28.8 $ 22.7 December 31, 2019 AEP AEP Texas APCo (in millions) Cash and Cash Equivalents $ 246.8 $ 3.1 $ 3.3 Restricted Cash 185.8 154.7 23.5 Total Cash, Cash Equivalents and Restricted Cash $ 432.6 $ 157.8 $ 26.8 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, which is carried at the lower of average cost or net realizable value. Materials and supplies inventories are carried at average cost. 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. The assessment is performed separately by each participating AEP subsidiary, which inherently contemplates any differences in geographical risk characteristics for the allowance. 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 based upon a 12-month rolling average of bad debt write-offs in proportion to gross accounts receivable, unless specifically identified. In addition to these processes, management contemplates available current information, as well as any reasonable and supportable forecast information, to determine if allowances for uncollectible accounts should be further adjusted in accordance with the accounting guidance for “Credit Losses.” Management’s assessments contemplate expected losses over the life of the accounts receivable. 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: Reliant Energy, Direct Energy and TXU Energy (a) 2020 2019 2018 Percentage of Total Revenues 46 % 48 % 45 % Percentage of Accounts Receivable – Customers 40 % 43 % 35 % (a) In January 2021, NRG Energy, parent company of Reliant Energy, completed a deal to purchase Direct Energy from Centrica. 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 2020 2019 2018 Percentage of Total Revenues 78 % 79 % 77 % Percentage of Total Accounts Receivable 78 % 78 % 84 % 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 on the statements of income. 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. The Registrants share the majority of their Off-system Sales margins to customers either through an active FAC or other rate mechanisms. 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 19 - 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 r

New Accounting Standards

New Accounting Standards	12 Months Ended
	Dec. 31, 2020
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 2016-13 “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. New standard implementation activities included: (a) the identification and evaluation of the population of financial instruments within the AEP system that are subject to the new standard, (b) the development of supporting valuation models to also contemplate appropriate metrics for current and supportable forecasted information and (c) the development of disclosures to comply with the requirements of ASU 2016-13. 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. Management adopted ASU 2016-13 and its related implementation guidance effective January 1, 2020, by means of an immaterial cumulative-effect adjustment to Retained Earnings on 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. ASU 2020-04 “Reference Rate Reform: Facilitation of the Effects of Reference Rate Reform on Financial Reporting” (ASU 2020-04) In March 2020, the FASB issued ASU 2020-04 providing guidance to ease the potential burden in accounting for Reference Rate Reform on financial reporting. The new standard is elective and applies to all entities, subject to meeting certain criteria, that have contracts, hedging relationships, and other transactions that reference the London Interbank Offered Rate (LIBOR) or another reference rate expected to be discontinued because of Reference Rate Reform. The new standard establishes a general contract modification principle that entities can apply in other areas that may be affected by Reference Rate Reform and certain elective hedge accounting expedients. Under the new standard, an entity may make a one-time election to sell or to transfer to the available-for-sale or trading classifications (or both sell and transfer), debt securities that both reference an affected rate, and were classified as held-to-maturity before January 1, 2020.

Comprehensive Income

Comprehensive Income	12 Months Ended
	Dec. 31, 2020
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, 2020, 2019 and 2018. 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 information. AEP Cash Flow Hedges Pension and OPEB For the Year Ended December 31, 2020 Commodity Interest Rate Amortization of Deferred Costs Changes in Funded Status Total (in millions) Balance in AOCI as of December 31, 2019 $ (103.5) $ (11.5) $ 130.7 $ (163.4) $ (147.7) Change in Fair Value Recognized in AOCI (89.2) (39.9) (a) — 62.7 (66.4) Amount of (Gain) Loss Reclassified from AOCI Generation & Marketing Revenues (b) (0.4) — — — (0.4) Purchased Electricity for Resale (b) 167.6 — — — 167.6 Interest Expense (b) — 4.9 — — 4.9 Amortization of Prior Service Cost (Credit) — — (19.2) — (19.2) Amortization of Actuarial (Gains) Losses — — 10.3 — 10.3 Reclassifications from AOCI, before Income Tax (Expense) Benefit 167.2 4.9 (8.9) — 163.2 Income Tax (Expense) Benefit 35.1 1.0 (1.9) — 34.2 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 132.1 3.9 (7.0) — 129.0 Net Current Period Other Comprehensive Income (Loss) 42.9 (36.0) (7.0) 62.7 62.6 Balance in AOCI as of December 31, 2020 $ (60.6) $ (47.5) $ 123.7 $ (100.7) $ (85.1) 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) Cash Flow Hedges Pension and OPEB For the Year Ended December 31, 2018 Commodity Interest Rate Securities 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) AEP Texas Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2020 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2019 $ (3.4) $ 4.9 $ (14.3) $ (12.8) Change in Fair Value Recognized in AOCI 0.1 — 2.6 2.7 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) 1.1 0.2 2.6 3.9 Balance in AOCI as of December 31, 2020 $ (2.3) $ 5.1 $ (11.7) $ (8.9) 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 ASU 2018-02 Adoption — — — — 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) APCo Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2020 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2019 $ 0.9 $ 9.2 $ (5.1) $ 5.0 Change in Fair Value Recognized in AOCI (0.7) — 7.7 7.0 Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (1.3) — — (1.3) Amortization of Prior Service Cost (Credit) — (5.3) — (5.3) Amortization of Actuarial (Gains) Losses — 0.5 — 0.5 Reclassifications from AOCI, before Income Tax (Expense) Benefit (1.3) (4.8) — (6.1) Income Tax (Expense) Benefit (0.3) (1.0) — (1.3) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (1.0) (3.8) — (4.8) Net Current Period Other Comprehensive Income (Loss) (1.7) (3.8) 7.7 2.2 Balance in AOCI as of December 31, 2020 $ (0.8) $ 5.4 $ 2.6 $ 7.2 Pension and OPEB Amortization Changes in Cash Flow Hedges - 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 Amortization Changes in Cash Flow Hedges of Deferred Funded For the Year Ended December 31, 2018 Commodity Interest 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) I&M Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2020 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2019 $ (9.9) $ 4.9 $ (6.6) $ (11.6) Change in Fair Value Recognized in AOCI — — 3.1 3.1 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 — 0.7 — 0.7 Reclassifications from AOCI, before Income Tax (Expense) Benefit 2.0 (0.1) — 1.9 Income Tax (Expense) Benefit 0.4 — — 0.4 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 1.6 (0.1) — 1.5 Net Current Period Other Comprehensive Income (Loss) 1.6 (0.1) 3.1 4.6 Balance in AOCI as of December 31, 2020 $ (8.3) $ 4.8 $ (3.5) $ (7.0) 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) OPCo Cash Flow Hedge – For the Year Ended December 31, 2020 Interest Rate (in millions) Balance in AOCI as of December 31, 2019 $ — Change in Fair Value Recognized in AOCI — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) — Reclassifications from AOCI, before Income Tax (Expense) Benefit — Income Tax (Expense) Benefit — Reclassifications from AOCI, Net of Income Tax (Expense) Benefit — Net Current Period Other Comprehensive Income (Loss) — Balance in AOCI as of December 31, 2020 $ — 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 PSO Cash Flow Hedge – For the Year Ended December 31, 2020 Interest Rate (in millions) Balance in AOCI as of December 31, 2019 $ 1.1 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, 2020 $ 0.1 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 SWEPCo Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2020 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2019 $ (1.8) $ (1.3) $ 1.8 $ (1.3) Change in Fair Value Recognized in AOCI — — 3.2 3.2 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 — 0.1 — 0.1 Reclassifications from AOCI, before Income Tax (Expense) Benefit 1.9 (1.9) — — Income Tax (Expense) Benefit 0.4 (0.4) — — Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 1.5 (1.5) — — Net Current Period Other Comprehensive Income (Loss) 1.5 (1.5) 3.2 3.2 Balance in AOCI as of December 31, 2020 $ (0.3) $ (2.8) $ 5.0 $ 1.9 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) (a) The change in fair value includes $6 million and $4 million related to AEP's investment in joint venture wind farms acquired as part of the purchase of Sempra Renewables LLC for the years ended December 31, 2020 and 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, 2020
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. COVID-19 Pandemic During the first quarter of 2020, AEP’s electric operating companies informed both retail customers and state regulators that disconnections for non-payment were temporarily suspended. Shortly thereafter, AEP’s state regulators also imposed temporary moratoria on customary disconnection practices. During the third and the fourth quarters of 2020, most state regulators began to lift restrictions on disconnects. As of December 31, 2020, AEP had resumed disconnections in its regulated jurisdictions with the exception of Virginia, Kentucky and Arkansas. Disconnections resumed in Kentucky during January 2021. AEP continues to work with regulators and stakeholders in Virginia and Arkansas and management currently anticipates resuming customary disconnection practices in the first half of 2021. However, this timing could change if there is new legislation or other regulatory directives issued in the future. Continuing adverse economic conditions may result in the inability of customers to pay for electric service, which could affect revenue recognition and the collectability of accounts receivable. The Registrants have worked with their state commissions to achieve deferral authority for incremental expenses incurred due to COVID-19. All of AEP’s regulated jurisdictions have issued COVID-19 orders, granting deferral authority for incremental COVID-19 expenses, with the exception of Kentucky and Tennessee. If any costs related to COVID-19 are not recoverable, it could reduce future net income and cash flows and impact financial condition. 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% ROE. The filing included 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 sought a prudence determination on all transmission and distribution capital additions through 2018 included in interim rates from 2008 to December 2019. In April 2020, the PUCT issued an order approving a stipulation and settlement agreement. The order includes an annual base rate reduction of $40 million based upon a 9.4% ROE with a capital structure of 57.5% debt and 42.5% common equity effective with the first billing cycle in June 2020. The order provides recovery of $26 million in capitalized vegetation management expenses that were incurred through 2018. The order 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. The order requires AEP Texas to file its next base rate case within four years of the date that the final order was issued. The order also states future financially based capital incentives will not be included in interim transmission and distribution rates and contains various ring-fencing provisions. As a result of the final order, 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. In December 2019, as a result of the initial stipulation and settlement agreement, AEP Texas (a) recorded an impairment of $33 million related to capital investments, which included $10 million of 2019 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. AEP Texas Interim Transmission and Distribution Rates Through December 31, 2020, AEP Texas’ cumulative revenues from interim base rate increases that are subject to review is estimated to be $79 million. A base rate review could result in a refund to customers if AEP Texas incurs a disallowance of the transmission or distribution investment on which an interim increase was based. Management is unable to determine a range of potential losses, if any, that are reasonably possible of occurring. A revenue decrease, including a refund of interim transmission and distribution rates, could reduce future net income and cash flows and impact financial condition. AEP Texas is required to file for a comprehensive rate review no later than April 3, 2024. APCo and WPCo Rate Matters (Applies to AEP and APCo) 2017-2019 Virginia Triennial Review Amendments to Virginia law impacting investor-owned utilities were enacted, effective July 1, 2018, that required APCo to file a 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 the Virginia jurisdictional share of these plants was $93 million before cost of removal, including materials and supplies inventory and ARO balances. 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. As a result, management deemed these costs to be substantially recovered by APCo during the triennial review period. In March 2020, APCo submitted its 2017-2019 Virginia triennial earnings review filing and base rate case with the Virginia SCC as required by state law. APCo requested a $65 million annual increase in base rates based upon a proposed 9.9% ROE. The requested annual increase included $19 million related to depreciation for updated test year end depreciable balances and a proposed increase in APCo’s Virginia depreciation rates and $8 million related to APCo’s calculated shortfall in 2017-2019 Virginia earnings. Inclusive of the Virginia jurisdictional share of the $93 million expense associated with APCo’s retired coal-fired generation assets, APCo calculated its 2017-2019 Virginia earnings for the triennial period to be below the authorized ROE range. APCo is currently in the process of retiring and replacing its Virginia jurisdictional Automated Meter Reading (AMR) meters with AMI meters. As of December 31, 2020 and 2019, APCo had approximately $35 million and $51 million of Virginia jurisdictional AMR meters as well as $73 million and $75 million of Virginia jurisdictional AMI meters recorded on its balance sheets. APCo pursued full recovery of these assets through its Virginia depreciation rates as discussed above. In November 2020, the Virginia SCC issued an order concluding that APCo earned above its authorized ROE but within its ROE band for the 2017-2019 period, resulting in no refund to customers and no change to APCo base rates on a prospective basis. The Virginia SCC approved a prospective 9.2% ROE for APCo's 2020-2022 triennial review period with the continuation of a 140 basis point band (8.5% bottom, 9.2% midpoint, 9.9% top). This 9.2% authorized ROE will also be applied to certain APCo rate adjustment clauses. APCo’s earnings for the 2020-2022 triennial review will continue to be 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. Conversely, as defined by Virginia law, APCo is also eligible to defer for future recovery certain environmental and major storm operation and maintenance expenses up to the bottom of APCo’s authorized Virginia 2020-2022 earnings ROE band. The Virginia SCC also disagreed with APCo’s treatment of the retired coal-fired generation assets for regulatory purposes, and instead adopted the Virginia SCC Staff’s recommendation to treat the remaining unrecovered costs of the retired coal-fired generation assets as a regulatory asset to be amortized over 10 years as of the June 2015 retirement date. The Virginia SCC’s adoption of the Staff’s recommended regulatory treatment of the coal-fired generation assets resulted in a net $40 million increase to APCo’s 2020 pretax income. In addition, the Virginia SCC’s order also included: (a) implementation of the Staff-modified APCo 2017 depreciation study effective January 1, 2018 and (b) implementation of the Staff-modified APCo 2019 depreciation study effective January 1, 2020. The adoption of these depreciation studies resulted in an approximate $47 million reduction to APCo’s 2020 pretax income comprised of a $44 million reduction to revenues for amounts recognized in advance of the recording of depreciation expense for the periods January 2018 through October 2020 and a $3 million increase in depreciation expense for the periods November and December 2020. A corresponding regulatory liability was recorded for the $44 million reduction to revenues. The Virginia SCC’s approval of APCo’s 2019 depreciation study included the ongoing depreciation and recovery of APCo’s Virginia AMI/AMR meter balances. In November 2020, APCo filed a notice of appeal with the Virginia Supreme Court. In December 2020, an intervenor filed a petition at the Virginia SCC requesting reconsideration of: (a) the failure of the Virginia SCC to apply a threshold earnings test to the approved regulatory asset for APCo’s closed coal-fired generation assets, (b) the Virginia SCC’s use of a 2011 benchmark study to measure the replacement value of capacity for purposes of APCo’s 2017 – 2019 earnings test and (c) the reasonableness and prudency of APCo’s investments in AMI meters. In December 2020, APCo filed a petition at the Virginia SCC requesting reconsideration of: (a) certain issues related to APCo’s going-forward rates and (b) the Virginia SCC’s decision to deny APCo tariff changes that align rates with underlying costs. For APCo’s going-forward rates, APCo requested that the Virginia SCC clarify its final order and whether APCo’s current rates will allow it to earn a fair return. If the Virginia SCC’s order did conclude on APCo’s ability to earn a fair return through existing base rates, APCo further requested that the Virginia SCC clarify whether it has the authority to also permit an increase in base rates. If the Virginia SCC did not conclude on APCo’s ability to earn a fair return, APCo requested the Virginia SCC provide such a conclusion. In January 2021, as requested by the Virginia SCC, APCo filed briefs related to the petition for reconsideration. If the Virginia SCC issues an unfavorable ruling related to the intervenor petition, it could reduce future net income and cash flows and impact financial condition. West Virginia ENEC and Vegetation Management Riders In June 2020, the WVPSC issued an order directing APCo and WPCo to increase rider rates relating to ENEC and vegetation management by a combined $101 million ($81 million related to APCo) over twelve months beginning September 2020. This increase will be partially offset by a refund of $38 million ($31 million related to APCo) of Excess ADIT that is not subject to normalization requirements over ten months beginning September 2020. These transactions will result in no overall impact to net income. 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 interim rate changes that can be filed twice annually and are subject to review and possible true-up in the next base rate proceeding. Through December 31, 2020, AEP’s share of ETT’s cumulative revenues that are subject to review is estimated to be $1.2 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 required ETT to file for a comprehensive base rate review no later than February 1, 2021. In December 2020, ETT and various intervenors filed a stipulation and settlement agreement with the PUCT. The agreement maintained ETT’s previously allowed ROE and capital structure and includes: (a) an $8 million decrease to the current annual revenue requirement effective February 1, 2021, (b) ETT must make an interim transmission cost of service filing by April 1, 2021, (c) a $2 million line item decrease to the revenue requirement determined in each interim transmission cost of service filing until the filing of the next comprehensive base rate review and (d) no determination of prudence on any transmission investment added since ETT’s last comprehensive base rate review, which would leave the $1.2 billion of cumulative revenues above subject to review in the next comprehensive base rate review. In January 2021, the PUCT approved the stipulation and settlement agreement. As part of the approved agreement, new rates were implemented in February 2021 and ETT is required to file for a comprehensive base rate review no later than February 1, 2023. I&M Rate Matters (Applies to AEP and I&M) 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 was based upon a proposed 10.5% ROE. The proposed annual increase included $78 million related to a proposed annual increase in depreciation expense. The requested annual increase in depreciation expense included $52 million related to proposed investments and $26 million related to increased depreciation rates. The request included the continuation of all existing riders and a new AMI rider for proposed meter projects. In March 2020, the IURC issued an order approving a phased-in increase in base rates of up to $77 million based upon an ROE of 9.7%. This approved phase-in increase includes: (a) an annual increase in base rates of $44 million effective March 2020 and (b) an annual increase in base rates of up to $77 million, effective January 2021, based on the IURC-approved forecast of December 31, 2020 Indiana jurisdictional electric plant in service. In January 2021, I&M updated its Indiana retail rates with the IURC based on actual December 31, 2020 I&M Indiana jurisdictional electric plant in service, resulting in a $60 million net annual base rate increase when compared to I&M Indiana base rate levels prior to March 2020. The order also approved the majority of I&M’s proposed changes in depreciation as well as the test year level of AMI deployment, but did not approve a cost recovery rider for AMI investments made in subsequent years. The order rejected I&M’s proposed re-allocation of capacity costs related to the loss of a significant FERC wholesale contract, which negatively impacts I&M’s annual pretax earnings by approximately $20 million starting June 2020. KPCo Rate Matters (Applies to AEP) 2020 Kentucky Base Rate Case In June 2020, KPCo filed a request with the KPSC for a $65 million net annual increase in base rates based upon a proposed 10% ROE with the increase to be implemented no earlier than January 2021. The filing proposes that KPCo would offset the first year of rate increases by refunding Excess ADIT that is not subject to normalization requirements to customers. Additionally, KPCo requested recovery of the previously authorized deferral of $50 million of Rockport Plant UPA expenses and related carrying charges over a 5-year period beginning in December 2022, through an existing purchased power rider. In January 2021, the KPSC issued an order approving an annual increase in base rates of $52 million based upon an ROE of 9.3% effective with billing cycles mid-January 2021. The order shortened the previously authorized refund period for Excess ADIT that is not subject to normalization requirements being refunded through a rider from 18 years to 3 years. In addition, the order approved recovery of certain annual PJM OATT expenses above/below the corresponding level recovered in base rates through a rider until KPCo’s next base case; however, recovery of these transmission costs will be re-examined by the KPSC in KPCo’s next base case. The KPSC deferred KPCo’s request to authorize a specific recovery period and mechanism for the previously authorized deferral of $50 million of Rockport Plant UPA expenses and related carrying charges to a future proceeding. The order requires KPCo to submit its next base case in June 2023 for rates effective in January 2024. In February 2021, KPCo filed for rehearing with the KPSC challenging various adjustments that were made in the order and requesting certain clarifications. Also in February 2021, the KPSC issued an order on rehearing that modified the approved annual increase in base rates from $52 million to $53 million and clarified several items, including the timing of the future proceeding to address a specific recovery period and mechanism for the previously authorized deferral of $50 million of Rockport Plant Unit Power Agreement expenses and related carrying charges. The KPSC will initiate a future proceeding to address a specific recovery period and mechanism for the deferral after KPCo makes a written filing identifying the capacity replacement for the Rockport Unit Power Agreement, including the name of the capacity resource and related reasonably anticipated costs. OPCo Rate Matters (Applies to AEP and OPCo) 2020 Ohio Base Rate Case In June 2020, OPCo filed a request with the PUCO for a $42 million annual increase in base rates based upon a proposed 10.15% ROE net of existing riders. Additionally, OPCo filed a request with the PUCO for a 60-day temporary delay of the normal rate case proceeding due to the COVID-19 pandemic with rates expected to be effective approximately mid-2021. In November 2020, PUCO staff filed testimony supporting an annual revenue decrease ranging from $102 million to $123 million based upon an ROE of 8.76% to 9.78%. The difference between OPCo’s request and the staff testimony are primarily due to reductions in: (a) demand-side management programs of $40 million, (b) ROE ranging from $9 million to $30 million, (c) employee-related expenses of $23 million, (d) rate base of $19 million, (e) property taxes of $17 million, (f) other various expenses of $15 million, (g) depreciation expense of $11 million and (h) vegetation management programs of $10 million which is subject to over/under-recovery through a rider. The staff’s proposed disallowance of plant in service could also result in a write-off of up to $27 million. In addition, the staff recommended that capitalized incentives be excluded from base rates prospectively and also recommended annual revenue caps for the DIR of $57 million in 2021, $78 million in 2022, $96 million in 2023 and $46 million for the first five months of 2024. In December 2020, OPCo and intervenors filed objections. A procedural schedule for the case is pending due to ongoing settlement discussions. If any of the requested costs are not recoverable, it could reduce future net income and cash flows and impact financial condition. 2019 Ohio DIR Audit OPCo conducts business under an ESP as approved by the PUCO which subjects the DIR to annual audits. In August 2020, a third-party consulting company filed an audit report with the PUCO indicating that OPCo exceeded its 2019 authorized revenue limit by $17 million. Management disagrees with the audit results and believes that OPCo was below its authorized revenue limit in 2019. The PUCO has not yet issued a procedural schedule to address the audit results. If the results of the audit are upheld by the PUCO and any refunds to customers or revenue reductions are ordered, it could reduce future net income and cash flows and impact financial condition. 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 the fourth quarter of 2019 and first quarter of 2020, SWEPCo and various intervenors filed briefs with the Texas Supreme Court. In August 2020, the Texas Supreme Court granted SWEPCo’s petition for review and oral arguments were held in December 2020. SWEPCo expects a decision from the Texas Supreme Court in 2021. As of December 31, 2020, the net book value of Turk Plant was $1.4 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% ROE. In January 2018, the PUCT issued a final order approving a net increase in Texas annual revenues of $50 million based upon a ROE 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. In July 2020, the LPSC issued an order approving an unopposed stipulation and settlement agreement for a one-time refund of $6 million over three months beginning in August 2020. Hurricane Laura In August 2020, Hurricane Laura hit the coasts of Louisiana and Texas, causing power outages to more than 130,000 customers across SWEPCo’s service territories. Prior to Hurricane Laura, SWEPCo did not have a catastrophe reserve or automatic deferral authority within any of its jurisdictions. In October 2020, the LPSC issued an order allowing Louisiana utilities, including SWEPCo, to establish a regulatory asset to track and defer expenses associated with Hurricane Laura. In October 2020, as part of the 2020 Texas Base Rate Case, SWEPCo requested deferral authority of incremental other operation and maintenance expenses. As of December 31, 2020, management estimates that SWEPCo has incurred incremental other operation and maintenance expenses of $84 million ($82 million of which has been deferred as a regulatory asset related to the Louisiana jurisdiction) and incremental capital expenditures of $23 million, all of which is related to the Louisiana jurisdiction. If any costs related to Hurricane Laura are not recoverable, it could reduce future net income and cash flows and impact financial condition. Hurricane Delta In October 2020, Hurricane Delta hit the coast of Louisiana, causing power outages to more than 23,000 customers in SWEPCo’s Louisiana jurisdiction. In November 2020, the LPSC issued an order allowing Louisiana utilities, including SWEPCo, to establish a regulatory asset to track and defer expenses associated with Hurricane Delta. As of December 31, 2020, management estimates that SWEPCo has incurred incremental other operation and maintenance expenses of $17 million, which has been deferred as a regulatory asset. Also, management estimates that SWEPCo has incurred incremental capital expenditures of $2 million. If any costs related to Hurricane Delta are not recoverable, it could reduce future net income and cash flows and impact financial condition. 2020 Texas Base Rate Case In October 2020, SWEPCo filed a request with the PUCT for a $105 million annual increase in Texas base rates based upon a proposed 10.35% ROE. The request would move transmission and distribution interim revenues recovered through riders into base rates. Eliminating these riders would result in a net annual requested base rate increase of $90 million primarily due to increased investments. The proposed net annual increase: (a) includes $5 million related to vegetation management to maintain and improve the reliability of its Texas jurisdictional distribution system, (b) requests a $10 million annual depreciation increase and (c) seeks $2 million annually to establish a storm catastrophe reserve. In addition, SWEPCo also requested recovery of the Texas jurisdictional share of the Dolet Hills Power Station of $45 million which is expected to be retired by the end of 2021. Intervenor and staff testimony is scheduled to be filed in March and April 2021, respectively. If any of these costs are not recoverable, it could reduce future net income and cash flows and impact financial condition. 2020 Louisiana Base Rate Case In December 2020, SWEPCo filed a request with the LPSC for a $134 million annual increase in Louisiana base rates based upon a proposed 10.35% ROE. The request would extend the formula rate plan for five years and includes modifications to the formula rate plan to allow for forward-looking transmission costs, reflects the impact of net operating losses associated with the acceleration of certain tax benefits and incorporates future federal corporate income tax changes. The proposed net annual increase: (a) requests a $32 million annual depreciation increase to recover Louisiana’s share of the Dolet Hills Power Station, Pirkey Power Plant and Welsh Plant, all of which are expected to be retired early, and (b) includes $10 million annually to recover deferred other operation and maintenance expenses related to Hurricanes Laura and Delta. If any of these costs are not recoverable, it could reduce future net income and cash flows and impact financial condition. FERC Rate Matters AFUDC Waiver (Applies to all Registrants except AEP Texas) In June 2020, FERC granted a temporary waiver providing utilities the option to elect to modify the existing AFUDC rate calculations in response to the COVID-19 pandemic. As a result of the waiver, the AFUDC formula for the 12-month period starting with March 2020 may be calculated using the simple average of the actual historical short-term debt balances for 2019, instead of current period short-term balances. All other aspects of the AFUDC formula remained unchanged. AEP subsidiaries including certain Registrant Subsidiaries elected to apply the waiver in July 2020. The impact upon election was immaterial on the Registrants’ financial statements. In February 2021, FERC issued an order extending the waiver through September 2021. OKTCo Radial Asset Transfer (Applies to AEP, AEPTCo and PSO) In August 2020, AEPSC filed a request with FERC, on behalf of PSO and OKTCo, to transfer OKTCo’s interests in its radial assets to PSO. OKTCo had previously constructed radial assets in the PS

Effects of Regulation

Effects of Regulation	12 Months Ended
	Dec. 31, 2020
Effects of Regulation	EFFECTS OF REGULATION The disclosures in this note apply to all Registrants unless indicated otherwise. Coal-Fired Generation Plants (Applies to AEP, PSO and SWEPCo) Compliance with extensive environmental regulations requires significant capital investment in environmental monitoring, installation of pollution control equipment, emission fees, disposal costs and permits. Management continuously evaluates cost estimates of complying with these regulations which has resulted in, and in the future may result in, a decision to retire coal-fired generating facilities earlier than their currently estimated useful lives. Management is seeking or will seek regulatory recovery, as necessary, for any net book value remaining when the plants are retired. To the extent the net book value of these generation assets are not deemed recoverable, it could materially reduce future net income and cash flows and impact financial condition. Regulated Generating Units that have been Retired PSO In September 2020, the Oklaunion Power Station was retired. As of December 31, 2020, PSO has a regulatory asset for accelerated depreciation pending approval recorded on its balance sheet for $34 million. PSO will seek recovery of the Oklaunion Power Station in its next base rate case. In October 2020, the Oklaunion Power Station site was sold to a nonaffiliated third-party. See “Oklaunion Power Station” section of Note 7 for additional information. SWEPCo In April 2016, Welsh Plant, Unit 2 was retired. As part of the 2016 Texas Base Rate Case, SWEPCo received approval from the PUCT to recover the Texas jurisdictional share of Welsh Plant, Unit 2. See “2016 Texas Base Rate Case” section of Note 4 for additional information. As part of the 2019 Arkansas Base Rate Case, SWEPCo received approval from the APSC to recover the Arkansas jurisdictional share of Welsh Plant, Unit 2. In December 2020, SWEPCo filed a request with the LPSC to recover the Louisiana jurisdictional share of Welsh Plant, Unit 2. As of December 31, 2020, SWEPCo has a regulatory asset for plant retirement costs pending approval recorded on its balance sheet for $35 million related to the Louisiana jurisdictional share of Welsh Plant, Unit 2. See “2020 Louisiana Base Rate Case” section of Note 4 for additional information. Regulated Generating Units to be Retired PSO In 2014, PSO received final approval from the EPA to close Northeastern Plant, Unit 3, in 2026. The plant was originally scheduled to close in 2040. As a result of the early retirement date, PSO revised the useful life of Northeastern Plant, Unit 3, to the projected retirement date of 2026 and the incremental depreciation is being deferred as a regulatory asset. In 2016, as part of the 2015 Oklahoma Base Rate Case, the OCC issued an order approving the continued depreciation of Northeastern Plant, Unit 3 through 2040. The order did not approve accelerating the recovery of the incremental depreciation based on the revised retirement date of 2026. SWEPCo In January 2020, as part of the 2019 Arkansas Base Rate Case, management announced that the Dolet Hills Power Station was probable of abandonment and was to be retired by December 2026. As a result of the announcement, SWEPCo began recording a regulatory asset for accelerated depreciation. In March 2020, management announced plans to retire the plant in 2021. In November 2020, management announced plans to retire Pirkey Power Plant in 2023 and that it will cease using coal at the Welsh Plant in 2028. As a result of the announcement, SWEPCo began recording a regulatory asset for accelerated depreciation. The table below summarizes the net book value including CWIP, before cost of removal and materials and supplies, as of December 31, 2020, of generating facilities planned for early retirement: Plant Net Accelerated Depreciation Regulatory Asset Cost of Removal Projected Current Authorized Annual (dollars in millions) Northeastern Plant, Unit 3 $ 198.4 $ 110.4 $ 19.8 (b) 2026 (c) $ 14.9 Dolet Hills Power Station 74.4 71.2 24.0 2021 (d) 60.8 Pirkey Power Plant 199.5 12.2 38.7 2023 (e) 13.8 Welsh Plant, Units 1 and 3 549.8 3.6 57.6 (f) 2028 (g) 33.3 (a) Represents the amount of annual depreciation that has been collected from customers over the prior 12-month period. (b) Includes Northeastern Plant, Unit 4, which was retired in 2016. Removal of Northeastern Plant, Unit 4, will be performed with Northeastern Plant, Unit 3, after retirement. (c) Northeastern Plant, Unit 3 is currently being recovered through 2040. (d) Dolet Hills Power Station is current being recovered through 2026 in the Louisiana jurisdiction and through 2046 in the Arkansas and Texas jurisdictions. (e) Pirkey Power Plant is currently being recovered through 2025 in the Louisiana jurisdiction and through 2045 in the Arkansas and Texas jurisdictions. (f) Includes Welsh Plant, Unit 2, which was retired in 2016. Removal of Welsh Plant, Unit 2, will be performed with Welsh Plant, Units 1 and 3, after retirement. (g) Unit 1 is being recovered through 2027 in the Louisiana jurisdiction and through 2037 in the Arkansas and Texas jurisdictions. Unit 3 is being recovered through 2032 in the Louisiana jurisdiction and through 2042 in the Arkansas and Texas jurisdictions. 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. DHLC provides 100% of the fuel supply to Dolet Hills Power Station. After careful consideration of current economic conditions, and particularly for the benefit of their customers, management of SWEPCo and CLECO determined DHLC would not proceed developing additional Oxbow Lignite Company (Oxbow) mining areas for future lignite extraction and ceased extraction of lignite at the mine in May 2020. Based on these actions, management revised the estimated useful life of DHLC’s and Oxbow’s assets to coincide with the date at which extraction was discontinued in the second quarter of 2020 and the date at which delivery of lignite is expected to cease in September 2021. Management also revised the useful life of the Dolet Hills Power Station to 2021 based on the remaining estimated fuel supply available for continued seasonal operation. In March 2020, primarily due to the revision in the useful life of DHLC, SWEPCo recorded a revision to increase estimated ARO liabilities by $21 million. In April 2020, SWEPCo and CLECO jointly filed a notification letter to the LPSC providing notice of the cessation of lignite mining. 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 $151 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 fuel agreements, SWEPCo’s fuel inventory and unbilled fuel costs from mining related activities were $131 million as of December 31, 2020. Also, as of December 31, 2020, SWEPCo had a net over-recovered fuel balance of $35 million, which includes fuel burned at 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. In October 2020, SWEPCo filed a request with the LPSC for recovery of the Louisiana share of these additional fuel costs. SWEPCo’s filing proposes to defer $36 million of fuel costs in 2021 and recover the deferral plus carrying costs over five years beginning in 2022. If any of these costs are not recoverable, it could reduce future net income and cash flows and impact financial condition. Pirkey Power Plant and Related Fuel Operations (Applies to AEP and SWEPCo) In November 2020, management announced plans to retire the Pirkey Power Plant in 2023. The Pirkey Power Plant costs are recoverable by SWEPCo through base rates. SWEPCo’s share of the net investment in the Pirkey Power Plant is $212 million, including CWIP, before cost of removal. Sabine is a mining operator providing mining services to the Pirkey Power Plant. Under the provisions of the mining agreement, SWEPCo is required to pay, as part of the cost of lignite delivered, an amount equal to mining costs plus a management fee. SWEPCo expects fuel deliveries, including billings of all fixed and operating costs, from Sabine to cease during the first quarter of 2023. Under the fuel agreements, SWEPCo’s fuel inventory and unbilled fuel costs from mining related activities were $193 million as of December 31, 2020. Also, as of December 31, 2020, SWEPCo had a net over-recovered fuel balance of $35 million, which includes fuel burned at the Pirkey Power Plant. Additional operational costs are expected to be incurred by Sabine and billed to SWEPCo, as well as land-related costs incurred by SWEPCo, prior to the closure of the Pirkey Power Plant 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. 2020 Texas Fuel Reconciliation (Applies to AEP and SWEPCo) In June 2020, SWEPCo filed a fuel reconciliation with the PUCT for its retail operations in Texas for the reconciliation period of March 1, 2017 to December 31, 2019. The fuel reconciliation included total fuel costs of $1.7 billion ($616 million of which is related to the Texas jurisdiction). In January 2021, various parties filed testimony recommending fuel cost disallowances totaling $125 million relating to the Texas jurisdiction. Also in January 2021, SWEPCo filed rebuttal testimony disputing the recommended disallowances. In February 2021, SWEPCo and various parties reached a settlement in principle which resulted in an immaterial impact to SWEPCo’s 2020 financial statements. If additional 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 2020 2019 Current Regulatory Assets (in millions) Under-recovered Fuel Costs - earns a return $ 41.4 $ 44.7 1 year Under-recovered Fuel Costs - does not earn a return 49.3 48.2 1 year Total Current Regulatory Assets $ 90.7 $ 92.9 Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Earning a Return Dolet Hills Power Station Accelerated Depreciation $ 71.2 $ — Kentucky Deferred Purchased Power Expenses 41.3 30.2 Plant Retirement Costs - Unrecovered Plant, Louisiana 35.2 35.2 Oklaunion Power Station Accelerated Depreciation 34.4 27.4 Other Regulatory Assets Pending Final Regulatory Approval 38.6 0.7 Total Regulatory Assets Currently Earning a Return 220.7 93.5 Regulatory Assets Currently Not Earning a Return Storm-Related Costs 134.2 7.2 Plant Retirement Costs - Asset Retirement Obligation Costs 25.9 30.1 COVID-19 24.9 — Vegetation Management Program - AEP Texas 3.8 29.4 Other Regulatory Assets Pending Final Regulatory Approval 32.7 21.5 Total Regulatory Assets Currently Not Earning a Return 221.5 88.2 Total Regulatory Assets Pending Final Regulatory Approval 442.2 181.7 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Unrecovered Plant (a) 713.1 690.5 23 years Plant Retirement Costs - Asset Retirement Obligation Costs 107.1 87.4 20 years Meter Replacement Costs 55.5 65.4 7 years Ohio Distribution Decoupling 46.6 31.4 2 years Environmental Control Projects 38.6 41.0 20 years Rockport Plant Dry Sorbent Injection System and Selective Catalytic Reduction 34.4 13.5 8 years Cook Plant Uprate Project 30.2 32.6 13 years Storm-Related Costs 11.5 21.3 2 years Advanced Metering System — 26.5 Other Regulatory Assets Approved for Recovery 94.4 79.6 various Total Regulatory Assets Currently Earning a Return 1,131.4 1,089.2 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 1,088.6 1,309.8 12 years Plant Retirement Costs - Asset Retirement Obligation Costs 212.7 28.8 22 years Unamortized Loss on Reacquired Debt 120.0 129.0 28 years Unrealized Loss on Forward Commitments 111.3 106.8 12 years Vegetation Management 67.8 43.6 5 years Cook Plant Nuclear Refueling Outage Levelization 39.5 63.8 2 years PJM/SPP Annual Formula Rate True-up 33.0 7.3 2 years Postemployment Benefits 29.1 34.2 3 years OVEC Purchased Power 27.4 1.5 2 years Fuel and Purchased Power Adjustment Rider 24.0 7.1 2 years Medicare Subsidy 18.6 23.2 4 years Other Regulatory Assets Approved for Recovery 181.4 132.8 various Total Regulatory Assets Currently Not Earning a Return 1,953.4 1,887.9 Total Regulatory Assets Approved for Recovery 3,084.8 2,977.1 Total Noncurrent Regulatory Assets $ 3,527.0 $ 3,158.8 (a) Northeastern Plant, Unit 3 is approved for recovery through 2040, but expected to retire in 2026. PSO records a regulatory asset for accelerated depreciation. See “Regulated Generating Units to be Retired” section above for additional information. AEP December 31, Remaining 2020 2019 Refund Period Current Regulatory Liabilities (in millions) Over-recovered Fuel Costs - pays a return $ 27.6 $ 77.5 1 year Over-recovered Fuel Costs - does not pay a return 25.0 9.1 1 year Total Current Regulatory Liabilities $ 52.6 $ 86.6 Noncurrent Regulatory Liabilities and Regulatory liabilities pending final regulatory determination: Regulatory Liabilities Currently Paying a Return Other Regulatory Liabilities Pending Final Regulatory Determination $ 2.5 $ — Total Regulatory Liabilities Currently Paying a Return 2.5 — Regulatory Liabilities Currently Not Paying a Return Other Regulatory Liabilities Pending Final Regulatory Determination 1.5 0.2 Total Regulatory Liabilities Currently Not Paying a Return 1.5 0.2 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 291.6 571.8 Excess ADIT that is Not Subject to Rate Normalization Requirements 193.3 291.0 (b) Total Income Tax Related Regulatory Liabilities 484.9 862.8 Total Regulatory Liabilities Pending Final Regulatory Determination 488.9 863.0 Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs 3,061.9 2,876.7 (c) Deferred Investment Tax Credits 4.1 6.2 33 years Ohio Basic Transmission Cost Rider — 37.2 Other Regulatory Liabilities Approved for Payment 25.2 14.4 various Total Regulatory Liabilities Currently Paying a Return 3,091.2 2,934.5 Regulatory Liabilities Currently Not Paying a Return Excess Nuclear Decommissioning Funding 1,476.6 1,236.0 (d) Deferred Investment Tax Credits 216.7 215.3 34 years PJM Transmission Enhancement Refund 56.2 67.3 5 years Transition and Restoration Charges - Texas 48.2 50.5 9 years 2017-2019 Virginia Triennial Revenue Provision 44.2 — 28 years Spent Nuclear Fuel 43.1 43.6 (d) Peak Demand Reduction/Energy Efficiency 26.3 23.0 2 years Deferred Gain on Sale of Rockport Unit 2 17.9 27.2 2 years Ohio Enhanced Service Reliability Plan 5.7 29.7 2 years Virginia Transmission Rate Adjustment Clause — 28.1 Other Regulatory Liabilities Approved for Payment 71.0 87.7 various Total Regulatory Liabilities Currently Not Paying a Return 2,005.9 1,808.4 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 3,485.7 3,303.0 (e) Excess ADIT that is Not Subject to Rate Normalization Requirements 714.9 890.5 10 years Income Taxes Subject to Flow Through (1,407.9) (1,341.8) 54 years Total Income Tax Related Regulatory Liabilities 2,792.7 2,851.7 Total Regulatory Liabilities Approved for Payment 7,889.8 7,594.6 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 8,378.7 $ 8,457.6 (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. (b) 2020 and 2019 amounts include approximately $173 million and $172 million, respectively, 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. (c) Relieved as removal costs are incurred. (d) Relieved when plant is decommissioned. (e) Refunded using ARAM. AEP Texas December 31, Remaining Regulatory Assets: 2020 2019 (in millions) Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Earning a Return Advanced Metering System $ 16.3 $ — Total Regulatory Assets Currently Earning a Return 16.3 — Regulatory Assets Currently Not Earning a Return COVID-19 10.5 — Vegetation Management Program 3.8 29.4 Other Regulatory Assets Pending Final Regulatory Approval 2.3 1.4 Total Regulatory Assets Currently Not Earning a Return 16.6 30.8 Total Regulatory Assets Pending Final Regulatory Approval 32.9 30.8 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Meter Replacement Costs 29.3 35.2 6 years Advanced Metering System — 26.5 Total Regulatory Assets Currently Earning a Return 29.3 61.7 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 145.0 172.0 12 years Vegetation Management Program 22.4 — 5 years Storm-Related Costs 17.1 — 4 years Peak Demand Reduction/Energy Efficiency 7.7 3.5 2 years Other Regulatory Assets Approved for Recovery 12.4 12.6 various Total Regulatory Assets Currently Not Earning a Return 204.6 188.1 Total Regulatory Assets Approved for Recovery 233.9 249.8 Total Noncurrent Regulatory Assets $ 266.8 $ 280.6 AEP Texas December 31, Remaining Regulatory Liabilities: 2020 2019 (in millions) Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits Regulatory liabilities pending final regulatory determination: Regulatory Liabilities Currently Paying a Return Other Regulatory Liabilities Pending Final Regulatory Determination $ 2.5 $ — Total Regulatory Liabilities Currently Paying a Return 2.5 — Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property — 274.9 Excess ADIT that is Not Subject to Rate Normalization Requirements (8.2) 87.1 Total Income Tax Related Regulatory Liabilities (8.2) 362.0 Total Regulatory Liabilities Pending Final Regulatory Determination (5.7) 362.0 Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs 718.3 689.6 (b) Other Regulatory Liabilities Approved for Payment 5.3 10.1 various Total Regulatory Liabilities Currently Paying a Return 723.6 699.7 Regulatory Liabilities Currently Not Paying a Return Transition and Restoration Charges 48.2 50.5 9 years Deferred Investment Tax Credits 8.5 9.6 20 years Other Regulatory Liabilities Approved for Payment 1.2 4.8 various Total Regulatory Liabilities Currently Not Paying a Return 57.9 64.9 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 506.0 236.5 (c) Excess ADIT that is Not Subject to Rate Normalization Requirements 41.7 — 1 years Income Taxes Subject to Flow Through (52.7) (46.2) 28 years Total Income Tax Related Regulatory Liabilities 495.0 190.3 Total Regulatory Liabilities Approved for Payment 1,276.5 954.9 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 1,270.8 $ 1,316.9 (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. (b) Relieved as removal costs are incurred. (c) Refunded using ARAM. AEPTCo December 31, Remaining Regulatory Assets: 2020 2019 (in millions) Noncurrent Regulatory Assets Regulatory assets approved for recovery: Regulatory Assets Currently Not Earning a Return PJM/SPP Annual Formula Rate True-up $ 15.1 $ 4.2 2 years Total Regulatory Assets Approved for Recovery 15.1 4.2 Total Noncurrent Regulatory Assets $ 15.1 $ 4.2 AEPTCo December 31, Remaining Regulatory Liabilities: 2020 2019 (in millions) Noncurrent Regulatory Liabilities Regulatory Liabilities Currently Paying a Return Asset Removal Costs $ 198.6 $ 141.0 (b) Total Regulatory Liabilities Currently Paying a Return 198.6 141.0 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 531.5 535.7 (c) Excess ADIT that is Not Subject to Rate Normalization Requirements (30.6) (35.4) 8 years Income Taxes Subject to Flow Through (117.7) (100.4) 38 years Total Income Tax Related Regulatory Liabilities 383.2 399.9 Total Regulatory Liabilities Approved for Payment 581.8 540.9 Total Noncurrent Regulatory Liabilities $ 581.8 $ 540.9 (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. (b) Relieved as removal costs are incurred. (c) Refunded using ARAM. APCo December 31, Remaining Regulatory Assets: 2020 2019 (in millions) Current Regulatory Assets Under-recovered Fuel Costs, Virginia - earns a return $ 3.3 $ 36.8 1 year Under-recovered Fuel Costs - does not earn a return 2.0 5.7 1 year Total Current Regulatory Assets $ 5.3 $ 42.5 Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Earning a Return COVID-19 - Virginia $ 3.7 $ — Plant Retirement Costs - Materials and Supplies — 0.5 Total Regulatory Assets Currently Earning a Return 3.7 0.5 Regulatory Assets Currently Not Earning a Return Plant Retirement Costs - Asset Retirement Obligation Costs 25.9 30.1 Environmental Expense Deferral - Virginia 9.3 — COVID-19 - West Virginia 1.5 — Other Regulatory Assets Pending Final Regulatory Approval 3.4 — Total Regulatory Assets Currently Not Earning a Return 40.1 30.1 Total Regulatory Assets Pending Final Regulatory Approval 43.8 30.6 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Unrecovered Plant (a) 122.4 86.4 23 years Other Regulatory Assets Approved for Recovery 1.0 0.5 various Total Regulatory Assets Currently Earning a Return 123.4 86.9 Regulatory Assets Currently Not Earning a Return Plant Retirement Costs - Asset Retirement Obligation Costs 202.7 — 15 years Pension and OPEB Funded Status 114.4 160.8 12 years Unamortized Loss on Reacquired Debt 82.1 85.5 25 years Vegetation Management Program - West Virginia 45.4 43.6 2 years Virginia Transmission Rate Adjustment Clause 18.8 — 2 years Peak Demand Reduction/Energy Efficiency 16.8 19.5 6 years Postemployment Benefits 13.5 15.9 3 years PJM Annual Formula Rate True-up 12.7 — 2 years Other Regulatory Assets Approved for Recovery 12.7 14.4 various Total Regulatory Assets Currently Not Earning a Return 519.1 339.7 Total Regulatory Assets Approved for Recovery 642.5 426.6 Total Noncurrent Regulatory Assets $ 686.3 $ 457.2 (a) December 31, 2020 amount includes Virginia and West Virginia jurisdictions. December 31, 2019 amount includes West Virginia jurisdiction. APCo December 31, Remaining Regulatory Liabilities: 2020 2019 (in millions) Noncurrent Regulatory Liabilities and Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs $ 678.9 $ 635.3 (b) Deferred Investment Tax Credits 0.3 0.5 33 years Total Regulatory Liabilities Currently Paying a Return 679.2 635.8 Regulatory Liabilities Currently Not Paying a Return 2017-2019 Virginia Triennial Revenue Provision 44.2 — 28 years PJM Transmission Enhancement Refund 16.3 19.5 5 years Virginia Transmission Rate Adjustment Clause — 28.1 Other Regulatory Liabilities Approved for Payment 12.3 18.0 various Total Regulatory Liabilities Currently Not Paying a Return 72.8 65.6 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 690.0 718.9 (c) Excess ADIT that is Not Subject to Rate Normalization Requirements 139.1 210.7 8 years Income Taxes Subject to Flow Through (356.4) (362.3) 24 years Total Income Tax Related Regulatory Liabilities 472.7 567.3 Total Regulatory Liabilities Approved for Payment 1,224.7 1,268.7 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 1,224.7 $ 1,268.7 (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. (b) Relieved as removal costs are incurred. (c) Refunded using ARAM. I&M December 31, Remaining Regulatory Assets: 2020 2019 (in millions) Current Regulatory Assets Under-recovered Fuel Costs - earns a return $ 5.4 $ 3.0 1 year Total Current Regulatory Assets $ 5.4 $ 3.0 Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Earning a Return Other Regulatory Assets Pending Final Regulatory Approval $ 0.5 $ — Total Regulatory Assets Currently Earning a Return 0.5 — Regulatory Assets Currently Not Earning a Return COVID-19 3.8 — Cook Plant Study Costs — 7.6 Other Regulatory Assets Pending Final Regulatory Approval — 0.1 Total Regulatory Assets Currently Not Earning a Return 3.8 7.7 Total Regulatory Assets Pending Final Regulatory Approval 4.3 7.7 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Unrecovered Plant 191.5 214.9 8 years Rockport Plant Dry Sorbent Injection System and Selective Catalytic Reduction 34.4 13.5 8 years Cook Plant Uprate Project 30.2 32.6 13 years Deferred Cook Plant Life Cycle Management Project Costs 14.1 15.1 14 years Cook Plant Turbine 11.1 13.4 18 years Cook Plant Study Costs - Indiana 10.1 — 15 years Other Regulatory Assets Approved for Recovery 7.0 6.9 various Total Regulatory Assets Currently Earning a Return 298.4 296.4 Regulatory Assets Currently Not Earning a Return Cook Plant Nuclear Refueling Outage Levelization 39.5 63.8 2 years Pension and OPEB Funded Status 25.7 67.5 12 years Unamortized Loss on Reacquired Debt 15.7 17.2 28 years Postemployment Benefits 4.9 7.2 3 years Other Regulatory Assets Approved for Recovery 16.3 22.3 various Total Regulatory Assets Currently Not Earning a Return 102.1 178.0 Total Regulatory Assets Approved for Recovery 400.5 474.4 Total Noncurrent Regulatory Assets $ 404.8 $ 482.1 I&M December 31, Remaining Regulatory Liabilities: 2020 2019 (in millions) Current Regulatory Liabilities Over-recovered Fuel Costs, Indiana - does not pay a return $ 20.8 $ 6.1 1 year Total Current Regulatory Liabilities $ 20.8 $ 6.1 Noncurrent Regulatory Liabilities and Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs $ 168.2 $ 166.7 (b) Other Regulatory Liabilities Approved for Payment 17.4 0.3 various Total Regulatory Liabilities Currently Paying a Return 185.6 167.0 Regulatory Liabilities Currently Not Paying a Return Excess Nuclear Decommissioning Funding 1,476.6 1,236.0 (c) Spent Nuclear Fuel 43.1 43.6 (c) Deferred Investment Tax Credits 21.3 25.8 19 years PJM Costs and Off-system Sales Margin Sharing - Indiana 13.3 17.0 2 years PJM Transmission Enhancement Refund 9.9 11.8 5 years Deferred Gain on Sale of Rockport Unit 2 7.2 10.9 2 years Other Regulatory Liabilities Approved for Payment 30.1 24.9 various Total Regulatory Liabilities Currently Not Paying a Return 1,601.5 1,370.0 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 450.6 470.9 (d) Excess ADIT that is Not Subject to Rate Normalization Requirements 136.2 184.5 4 years Income Taxes Subject to Flow Through (332.0) (301.0) 20 years Total Income Tax Related Regulatory Liabilities 254.8 354.4 Total Regulatory Liabilities Approved for Payment 2,041.9 1,891.4 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 2,041.9 $ 1,891.4 (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. (b) Relieved as removal costs are incurred. (c) Relieved when plant is decommissioned. (d) Refunded using ARAM. OPCo December 31, Remaining Regulatory Assets: 2020 2019 (in millions) Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Not Earning a Return COVID-19 $ 4.4 $ — Storm-Related Costs 4.0 — Other Regulatory Assets Pending Final Regulatory Approval — 0.1 Total Regulatory Assets Pending Final Regulatory Approval 8.4 0.1 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Ohio Distribution Decoupling 46.6 31.4 2 years Ohio Basic Transmission Cost Rider 12.3 — 2 years Other Regulatory Assets Approved for Recovery 1.3 — various Total Regulatory Assets Currently Earning a Return 60.2 31.4 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 130.7 167.3 12 years Unrealized Loss on Forward Commitments 110.0 103.6 12 years OVEC Purchased Power 27.4 1.5 2 years Smart Grid Costs 19.2 13.7 2 years Distribution Investment Rider 7.4 10.9 2 years Postemployment Benefits 6.7 7.6 3 years Other Regulatory Assets Approved for Recovery 15.8 15.7 various Total Regulatory Assets Currently Not Earning a Return 317.2 320.3 Total Regulatory Assets Approved for Recovery 377.4 351.7 Total Noncurrent Regulatory Assets $ 385.8 $ 351.8 OPCo December 31, Remaining 2020 2019 Regulatory Liabilities: (in millions) Current Regulatory Liabilities Over-recovered Fuel Costs - does not pay a return $ 3.9 $ 2.8 1 year Total Current Regulatory Liabilities $ 3.9 $ 2.8 Noncurrent Regulatory Liabilities and 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 458.4 446.3 (b) Ohio Basic Transmission Cost Rider — 37.2 Other Regulatory Liabilities Approved for Payment — 1.3 Total Regulatory Liabilities Currently Paying a Return 458.4 484.8 Regulatory Liabilities Currently Not Paying a Return PJM Transmission Enhancement Refund 24.5 29.4 5 years Peak Demand Reduction/Energy Efficiency 19.9 19.7 2 years Ohio Enhanced Service Reliability Plan 5.7 29.7 2 years Other Regulatory Liabilities Approved for Payment 0.7 2.9 various Total Regulatory Liabilities Currently Not Paying a Return 50.8 81.7 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 334.6 341.6 (c) Excess ADIT that is Not Subject to Rate Normalization Requirements 223.9 252.3 8 years Income Taxes Subject to Flow Through (62.7) (69.7) 29 years Total Income Tax Related Regulatory Liabilities 495.8 524.2 Total Regulatory Liabilities Approved for Payment 1,005.0 1,090.7 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 1,005.2 $ 1,090.9 (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. (b) Relieved as removal costs are incurred. (c) Refunded using ARAM. PSO December 31, Remaining 2020 2019 Regulatory Assets: (in millions) Current Regulatory Assets Under-recovered Fuel Costs - earns a return $

Commitments, Guarantees and Con

Commitments, Guarantees and Contingencies	12 Months Ended
	Dec. 31, 2020
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, 2020: Contractual Commitments - AEP Less Than 2-3 Years 4-5 Years After Total (in millions) Fuel Purchase Contracts (a) $ 763.9 $ 715.1 $ 212.9 $ 381.5 $ 2,073.4 Energy and Capacity Purchase Contracts 211.6 291.8 277.0 928.5 1,708.9 Total $ 975.5 $ 1,006.9 $ 489.9 $ 1,310.0 $ 3,782.3 Contractual Commitments - APCo Less Than 2-3 Years 4-5 Years After Total (in millions) Fuel Purchase Contracts (a) $ 362.8 $ 217.6 $ 11.6 $ 16.3 $ 608.3 Energy and Capacity Purchase Contracts 35.5 72.5 73.9 230.2 412.1 Total $ 398.3 $ 290.1 $ 85.5 $ 246.5 $ 1,020.4 Contractual Commitments - I&M Less Than 2-3 Years 4-5 Years After Total (in millions) Fuel Purchase Contracts (a) $ 157.7 $ 278.9 $ 189.3 $ 332.7 $ 958.6 Energy and Capacity Purchase Contracts 165.2 196.7 60.9 254.6 677.4 Total $ 322.9 $ 475.6 $ 250.2 $ 587.3 $ 1,636.0 Contractual Commitments - OPCo Less Than 2-3 Years 4-5 Years After Total (in millions) Energy and Capacity Purchase Contracts $ 28.8 $ 58.2 $ 58.1 $ 263.3 $ 408.4 Contractual Commitments - PSO Less Than 2-3 Years 4-5 Years After Total (in millions) Fuel Purchase Contracts (a) $ 25.3 $ 36.2 $ — $ — $ 61.5 Energy and Capacity Purchase Contracts 89.6 77.4 66.8 160.0 393.8 Total $ 114.9 $ 113.6 $ 66.8 $ 160.0 $ 455.3 Contractual Commitments - SWEPCo Less Than 2-3 Years 4-5 Years After Total (in millions) Fuel Purchase Contracts (a) $ 68.5 $ 39.2 $ — $ — $ 107.7 Energy and Capacity Purchase Contracts 8.3 8.4 8.4 4.2 29.3 Total $ 76.8 $ 47.6 $ 8.4 $ 4.2 $ 137.0 (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 and AEP Texas) 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, 2020, 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, 2020 were as follows: Company Amount Maturity (in millions) AEP $ 179.8 January 2021 to December 2021 AEP Texas 2.2 July 2021 Guarantees of Equity Method Investees (Applies to AEP) In April 2019, AEP acquired Sempra Renewables LLC. The transaction resulted in the acquisition of a 50% ownership interest in five non-consolidated joint ventures and the acquisition of two tax equity partnerships. 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, 2020, the maximum potential amount of future payments associated with these guarantees was $157 million, with the last guarantee expiring in December 2037. The non-contingent liability recorded associated with these guarantees was $31 million, with an additional $1 million expected credit loss liability for the contingent portion of the guarantees. Management considered historical losses, economic conditions, and reasonable and supportable forecasts in the calculation of the expected credit loss. As the joint ventures generate cash flows through PPAs, the measurement of the contingent portion of the guarantee liability is based upon assessments of the credit quality and default probabilities of the respective PPA counterparties. 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, 2020, 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, 2020, 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, 2020, management’s estimates do not anticipate material clean-up costs for identified Superfund sites. Virginia House Bill 443 (Applies to AEP and APCo) In March 2020, Virginia’s Governor signed House Bill 443 (HB 443), effective July 2020, requiring APCo to close certain ash disposal units at the retired Glen Lyn Station by removal of all coal combustion material. As a result, in June 2020, APCo recorded a $199 million revision to increase estimated Glen Lyn Station ash disposal ARO liabilities. The closure is required to be completed within 15 years from the start of the excavation process. HB 443 provides for the recovery of all costs associated with closure by removal through the Virginia environmental rate adjustment clause (E-RAC). APCo is permitted to record carrying costs on the unrecovered balance of closure costs at a weighted-average cost of capital approved by the Virginia SCC. HB 443 also allows any closure costs allocated to non-Virginia jurisdictional customers, but not collected from such non-Virginia jurisdictional customers, to be recovered from Virginia jurisdictional customers through the E-RAC. APCo will submit filings with the Virginia SCC and the WVPSC requesting recovery of the respective Virginia and West Virginia jurisdictional shares of these Glen Lyn Station ARO costs. As of December 31, 2020, APCo has not yet incurred any incremental costs associated with the removal of coal combustion material at the Glen Lyn Station. 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 $4 million, $7 million and $8 million for the years ended December 31, 2020, 2019 and 2018, respectively. Decommissioning costs recovered from customers are deposited in external trusts. As of December 31, 2020 and 2019, the total decommissioning trust fund balances were $3 billion and $2.7 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, 2020 and 2019, fees and related interest of $281 million and $280 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 $324 million and $323 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 $24 million, $8 million and $11 million in 2020, 2019 and 2018, respectively, to recover costs and will be eligible to receive additional payment of annual claims for allowed costs that are incurred through December 31, 2022. The proceeds reduced costs for dry cask storage. As of December 31, 2020 and 2019, I&M deferred $14 million and $24 million, respectively, in Prepayments and Other Current Assets and $1 million and $1 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 $500 million. 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 $42 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 $13.8 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 $13.3 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. The district court’s stay of the lease litigation expired in August 2020. Upon expiration of the stay, plaintiffs filed a motion for partial summary judgment, arguing that the consent decree violates the facility lease and the participation agreement and requesting that the district court enter a judgment for the plaintiffs on their breach of contract claim. AEP’s memorandum in opposition to plaintiffs’ motion for partial summary judgement was filed in October 2020. At the parties’ request, the district court stayed the case until February 16, 2021 to provide the parties an opportunity to resolve the case, and the court has since extended the stay until April 26, 2021. Management will continue to defend against the claims and believes its financial statements appropriately reflect the potential outcome of the pending litigation. The ultimate outcome of the pending litigation could reduce future net income and cash flows and impact financial condition. 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 was resolved in December 2020 and did not have a material impact on net income, cash flows or financial condition. 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 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. The denial of those claims was appealed to the AEP System Retirement Plan Appeal Committee and the Committee upheld the denial of claims. Management will continue to defend against the claims. Management is unable to determine a range of potential losses that is reasonably possible of occurring. Litigation Related to Ohio House Bill 6 (Applies to AEP and OPCo) In August 2020, an AEP shareholder filed a putative class action lawsuit in the United States District Court for the Southern District of Ohio against AEP and certain of its officers for alleged violations of securities laws. The complaint alleges misrepresentations or omissions by AEP regarding: (a) its alleged participation in public corruption with respect to the passage of Ohio House Bill 6, (b) its regulatory, legislative and lobbying activities in Ohio and (c) its clean energy strategy. The complaint seeks monetary damages among other forms of relief. The company will continue to defend against the claims. Management is unable to determine a range of potential losses that is reasonably possible of occurring. In January 2021, an AEP shareholder filed a derivative action in the United States District Court for the Southern District of Ohio purporting to assert claims on behalf of AEP against certain AEP officers and directors. In February 2021, a second AEP shareholder filed a similar derivative action in the Court of Common Pleas of Franklin County, Ohio. The derivative complaints allege the officers and directors made misrepresentations and omissions similar to those alleged in the putative securities class action lawsuit filed against AEP. The complaints assert claims for: (a) breach of fiduciary duty, (b) waste of corporate assets and (c) unjust enrichment and seek monetary damages and changes to AEP’s corporate governance and internal policies among other forms of relief. The company will continue to defend against the claims. Management is unable to determine a range of potential losses that is reasonably possible of occurring.

Acquisitions, Dispositions and

Acquisitions, Dispositions and Impairments	12 Months Ended
	Dec. 31, 2020
Impairments, Disposition and Assets and Liabilities Held for Sale	7. ACQUISITIONS, DISPOSITIONS AND IMPAIRMENTS The disclosures in this note apply to AEP unless indicated otherwise. ACQUISITIONS 2020 Santa Rita East (Generation & Marketing Segment) In November 2020, AEP acquired an additional 10% interest in Santa Rita East for approximately $44 million resulting in AEP having a total interest of 85%. The acquisition of the incremental ownership interest was accounted for as an equity transaction in accordance with the accounting guidance for "Consolidation" and reduced Noncontrolling Interests on the balance sheets by approximately $44 million. See Note 17 - Variable Interest Entities and Equity Method Investments for additional information. Desert Sky Wind Farm and Trent Wind Farm (Generation & Marketing Segment) In August 2020, AEP exercised its call right which required the nonaffiliated member of Desert Sky Wind Farm LLC and Trent Wind Farm LLC (collectively the LLCs) to sell its noncontrolling interest to AEP. The exercise price for the call right was determined using a discounted cash flow model with agreed input assumptions as well as updates to certain assumptions reasonably expected based on the actual results of the LLCs. As a result, the LLCs are wholly-owned by AEP and management has concluded that the LLCs are no longer VIEs. AEP paid $57 million in cash, derecognized $63 million of Redeemable Noncontrolling Interest within Mezzanine Equity and recorded an increase of $6 million of Paid-In Capital on the balance sheets. See Note 17 - Variable Interest Entities and Equity Method Investments for additional information. 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. 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. 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. 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.” See “Sempra Renewables LLC PPAs” section of Note 16 for additional information. 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 2020 Conesville Plant (Generation & Marketing Segment) In June 2020, AEP and a nonaffiliated joint-owner executed an Environmental Liability and Property Transfer and Asset Purchase Agreement with a nonaffiliated third-party related to the merchant Conesville Plant site. The purchaser took ownership of the assets and assumed responsibility for environmental liabilities, including ash pond closure, asbestos abatement and decommissioning and demolition of the Conesville Plant site. In consideration of the transfer of the acquired assets to the purchaser and the purchaser’s assumption of liabilities, AEP will pay a total of approximately $98 million over three years, derecognized $106 million in ARO and recorded an immaterial gain on the transaction which is recorded in Other Operation on the statements of income. AEP paid approximately $26 million at closing in June 2020 and made an additional payment of $10 million in the fourth quarter of 2020. AEP will make additional payments as detailed in the table below: 2021 2022 (in millions) First Quarter $ 9.6 $ 9.6 Second Quarter 9.6 9.6 Third Quarter 9.6 5.2 Fourth Quarter 9.6 — Total $ 38.4 $ 24.4 Oklaunion Power Station (Transmission and Distribution Segment and Vertically Integrated Utilities Segment) (Applies to AEP, AEP Texas and PSO) In October 2020, AEP Texas, PSO and a nonaffiliated joint-owner executed an Environmental Liability and Property Transfer and Asset Purchase Agreement with a nonaffiliated third-party related to the Oklaunion Power Station site. The purchaser took ownership of the assets and assumed responsibility for environmental liabilities, including ash pond closure, asbestos abatement and decommissioning and demolition of the Oklaunion Power Station site. The sale had an immaterial impact on the financial statements in the fourth quarter of 2020. 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 in Asset Impairments and Other Related Charges on the statements of income related to its previously retired coal-fired generation. As a result, management deemed these costs to be substantially recovered by APCo during the triennial review period. See “2017-2019 Virginia Triennial Review” 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. AEP initially impaired Racine in 2017 as discussed in the “2017 Merchant Generating Assets” section of the Acquisitions, Dispositions and Impairments Note within the 2019 Annual Report. Through the third quarter of 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, 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 were completed in 2020.

Benefit Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2020
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 non-qualified pension plans. Substantially all AEP employees are covered by the qualified plan or both the qualified and a non-qualified 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 rate-making 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 2020 2019 2020 2019 Discount Rate 2.50 % 3.25 % 2.55 % 3.30 % Interest Crediting Rate 4.00 % 4.00 % NA NA NA Not applicable. Pension Plans December 31, Assumption – Rate of Compensation Increase (a) 2020 2019 AEP 5.00 % 4.95 % AEP Texas 5.05 % 5.00 % APCo 4.85 % 4.80 % I&M 5.00 % 4.95 % OPCo 5.25 % 5.15 % PSO 5.05 % 5.05 % SWEPCo 4.90 % 4.90 % (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 2020, 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 2020 2019 2018 2020 2019 2018 Discount Rate 3.25 % 4.30 % 3.65 % 3.30 % 4.30 % 3.60 % Interest Crediting Rate 4.00 % 4.00 % 4.00 % NA NA NA Expected Return on Plan Assets 5.75 % 6.25 % 6.00 % 5.50 % 6.25 % 6.00 % NA Not applicable. Pension Plans Year Ended December 31, Assumption – Rate of Compensation Increase (a) 2020 2019 2018 AEP 5.00 % 4.95 % 4.85 % AEP Texas 5.05 % 5.00 % 4.95 % APCo 4.85 % 4.75 % 4.75 % I&M 5.00 % 4.95 % 4.90 % OPCo 5.25 % 5.20 % 5.00 % PSO 5.05 % 5.05 % 4.90 % SWEPCo 4.90 % 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. 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 2020 2019 Initial 6.50 % 6.00 % Ultimate 4.50 % 4.50 % Year Ultimate Reached 2029 2026 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, 2020, 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, 2020, the pension plans had an actuarial loss primarily due to a decrease in the discount rate, partially offset by a decrease in the assumed rate used to convert account balances to annuities. For the year ended December 31, 2020, the OPEB plans had an actuarial loss primarily due to a decrease in the discount rate and an update to the health care trend assumption, partially offset by updated projected per capita claims costs due to rate negotiations for Medicare advantage premium rates. 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. 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 2020 2019 2020 2019 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 5,236.8 $ 4,810.3 $ 1,225.4 $ 1,194.5 Service Cost 111.9 95.5 10.0 9.5 Interest Cost 167.9 204.4 39.8 50.5 Actuarial Loss 434.7 493.6 39.3 58.8 Plan Amendments — 0.2 (11.4) (11.0) Benefit Payments (406.8) (367.2) (131.0) (113.0) Participant Contributions — — 38.2 35.5 Medicare Subsidy — — 0.6 0.6 Benefit Obligation as of December 31, $ 5,544.5 $ 5,236.8 $ 1,210.9 $ 1,225.4 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 5,015.4 $ 4,695.9 $ 1,781.8 $ 1,534.2 Actual Gain on Plan Assets 832.4 681.1 253.0 321.0 Company Contributions (a) 115.6 5.6 4.7 4.1 Participant Contributions — — 38.2 35.5 Benefit Payments (406.8) (367.2) (131.0) (113.0) Fair Value of Plan Assets as of December 31, $ 5,556.6 $ 5,015.4 $ 1,946.7 $ 1,781.8 Funded (Underfunded) Status as of December 31, $ 12.1 $ (221.4) $ 735.8 $ 556.4 (a) Contributions to the qualified pension plan were $110 million and $0 for the years ended December 31, 2020 and 2019, respectively. Contributions to the non-qualified pension plans were $6 million and $6 million for the years ended December 31, 2020 and 2019, respectively. Pension Plans OPEB December 31, AEP 2020 2019 2020 2019 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ 93.5 $ — $ 771.9 $ 590.8 Other Current Liabilities – Accrued Short-term Benefit Liability (6.7) (6.1) (2.4) (2.6) Employee Benefits and Pension Obligations – Accrued Long-term Benefit Liability (74.7) (215.3) (33.7) (31.8) Funded (Underfunded) Status $ 12.1 $ (221.4) $ 735.8 $ 556.4 AEP Texas Pension Plans OPEB 2020 2019 2020 2019 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 441.2 $ 409.3 $ 97.8 $ 95.9 Service Cost 10.0 8.6 0.8 0.8 Interest Cost 13.9 17.5 3.2 4.0 Actuarial Loss 28.1 40.1 2.4 3.9 Plan Amendments — — (1.0) (0.9) Benefit Payments (40.0) (34.3) (10.0) (8.8) Participant Contributions — — 3.1 2.9 Benefit Obligation as of December 31, $ 453.2 $ 441.2 $ 96.3 $ 97.8 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 435.1 $ 410.7 $ 148.1 $ 129.9 Actual Gain on Plan Assets 67.2 58.3 21.1 24.0 Company Contributions 11.7 0.4 — 0.1 Participant Contributions — — 3.1 2.9 Benefit Payments (40.0) (34.3) (10.0) (8.8) Fair Value of Plan Assets as of December 31, $ 474.0 $ 435.1 $ 162.3 $ 148.1 Funded (Underfunded) Status as of December 31, $ 20.8 $ (6.1) $ 66.0 $ 50.3 Pension Plans OPEB December 31, AEP Texas 2020 2019 2020 2019 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ 24.7 $ — $ 66.0 $ 50.3 Other Current Liabilities – Accrued Short-term Benefit Liability (0.4) (0.4) — — Deferred Credits and Other Noncurrent Liabilities – Accrued Long-term Benefit Liability (3.5) (5.7) — — Funded (Underfunded) Status $ 20.8 $ (6.1) $ 66.0 $ 50.3 APCo Pension Plans OPEB 2020 2019 2020 2019 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 647.2 $ 603.1 $ 203.5 $ 205.5 Service Cost 10.5 9.4 1.0 1.0 Interest Cost 20.3 25.2 6.6 8.7 Actuarial Loss 40.0 52.9 5.6 4.7 Plan Amendments — — (1.8) (1.7) Benefit Payments (47.2) (43.4) (23.2) (20.8) Participant Contributions — — 6.3 5.9 Medicare Subsidy — — 0.2 0.2 Benefit Obligation as of December 31, $ 670.8 $ 647.2 $ 198.2 $ 203.5 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 637.0 $ 593.3 $ 271.0 $ 238.4 Actual Gain on Plan Assets 104.5 87.1 36.8 45.3 Company Contributions 7.0 — 2.1 2.2 Participant Contributions — — 6.3 5.9 Benefit Payments (47.2) (43.4) (23.2) (20.8) Fair Value of Plan Assets as of December 31, $ 701.3 $ 637.0 $ 293.0 $ 271.0 Funded (Underfunded) Status as of December 31, $ 30.5 $ (10.2) $ 94.8 $ 67.5 Pension Plans OPEB December 31, APCo 2020 2019 2020 2019 (in millions) Employee Benefits and Pension Assets – Prepaid Benefit Costs $ 31.0 $ — $ 119.1 $ 92.0 Other Current Liabilities – Accrued Short-term Benefit Liability — — (1.8) (2.0) Employee Benefits and Pension Obligations – Accrued Long-term Benefit Liability (0.5) (10.2) (22.5) (22.5) Funded (Underfunded) Status $ 30.5 $ (10.2) $ 94.8 $ 67.5 I&M Pension Plans OPEB 2020 2019 2020 2019 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 616.1 $ 567.0 $ 142.9 $ 138.3 Service Cost 15.4 13.4 1.4 1.4 Interest Cost 19.7 23.8 4.7 5.8 Actuarial Loss 44.3 49.8 5.1 8.1 Plan Amendments — — (1.6) (1.5) Benefit Payments (42.2) (37.9) (15.9) (13.6) Participant Contributions — — 4.8 4.4 Benefit Obligation as of December 31, $ 653.3 $ 616.1 $ 141.4 $ 142.9 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 630.5 $ 583.8 $ 216.3 $ 187.3 Actual Gain on Plan Assets 103.3 84.6 33.0 38.2 Company Contributions 6.5 — — — Participant Contributions — — 4.8 4.4 Benefit Payments (42.2) (37.9) (15.9) (13.6) Fair Value of Plan Assets as of December 31, $ 698.1 $ 630.5 $ 238.2 $ 216.3 Funded Status as of December 31, $ 44.8 $ 14.4 $ 96.8 $ 73.4 Pension Plans OPEB December 31, I&M 2020 2019 2020 2019 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ 46.5 $ 15.8 $ 96.8 $ 73.4 Deferred Credits and Other Noncurrent Liabilities – Accrued Long-term Benefit Liability (1.7) (1.4) — — Funded Status $ 44.8 $ 14.4 $ 96.8 $ 73.4 OPCo Pension Plans OPEB 2020 2019 2020 2019 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 487.8 $ 453.9 $ 130.2 $ 129.5 Service Cost 9.7 7.9 0.9 0.8 Interest Cost 15.4 19.1 4.2 5.5 Actuarial Loss 33.4 40.5 3.1 4.9 Plan Amendments — — (1.3) (1.2) Benefit Payments (36.0) (33.6) (15.0) (13.5) Participant Contributions — — 4.3 4.1 Medicare Subsidy — — — 0.1 Benefit Obligation as of December 31, $ 510.3 $ 487.8 $ 126.4 $ 130.2 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 499.1 $ 466.1 $ 197.1 $ 175.4 Actual Gain on Plan Assets 79.9 66.6 26.6 31.1 Company Contributions 0.1 — — — Participant Contributions — — 4.3 4.1 Benefit Payments (36.0) (33.6) (15.0) (13.5) Fair Value of Plan Assets as of December 31, $ 543.1 $ 499.1 $ 213.0 $ 197.1 Funded Status as of December 31, $ 32.8 $ 11.3 $ 86.6 $ 66.9 Pension Plans OPEB December 31, OPCo 2020 2019 2020 2019 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ 33.3 $ 11.7 $ 86.6 $ 66.9 Deferred Credits and Other Noncurrent Liabilities – Accrued Long-term Benefit Liability (0.5) (0.4) — — Funded Status $ 32.8 $ 11.3 $ 86.6 $ 66.9 PSO Pension Plans OPEB 2020 2019 2020 2019 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 267.5 $ 253.8 $ 64.7 $ 62.3 Service Cost 7.3 6.5 0.7 0.6 Interest Cost 8.5 10.6 2.1 2.6 Actuarial Loss 17.7 16.8 1.9 3.8 Plan Amendments — — (0.7) (0.7) Benefit Payments (21.1) (20.2) (6.8) (5.9) Participant Contributions — — 2.1 2.0 Benefit Obligation as of December 31, $ 279.9 $ 267.5 $ 64.0 $ 64.7 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 276.2 $ 261.2 $ 98.0 $ 84.3 Actual Gain on Plan Assets 44.6 34.7 14.5 17.6 Company Contributions 0.1 0.5 — — Participant Contributions — — 2.1 2.0 Benefit Payments (21.1) (20.2) (6.8) (5.9) Fair Value of Plan Assets as of December 31, $ 299.8 $ 276.2 $ 107.8 $ 98.0 Funded Status as of December 31, $ 19.9 $ 8.7 $ 43.8 $ 33.3 Pension Plans OPEB December 31, PSO 2020 2019 2020 2019 (in millions) Employee Benefits and Pension Assets – Prepaid Benefit Costs $ 21.9 $ 10.6 $ 43.8 $ 33.3 Other Current Liabilities – Accrued Short-term Benefit Liability (0.1) (0.1) — — Deferred Credits and Other Noncurrent Liabilities – Accrued Long-term Benefit Liability (1.9) (1.8) — — Funded Status $ 19.9 $ 8.7 $ 43.8 $ 33.3 SWEPCo Pension Plans OPEB 2020 2019 2020 2019 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 314.2 $ 291.4 $ 77.4 $ 72.7 Service Cost 9.9 8.6 0.8 0.8 Interest Cost 10.2 12.4 2.5 3.1 Actuarial Loss 27.4 25.5 2.5 6.0 Plan Amendments — — (0.8) (0.8) Benefit Payments (27.2) (23.7) (7.7) (6.6) Participant Contributions — — 2.4 2.2 Benefit Obligation as of December 31, $ 334.5 $ 314.2 $ 77.1 $ 77.4 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 296.9 $ 281.0 $ 117.2 $ 98.5 Actual Gain on Plan Assets 48.2 39.5 18.0 23.1 Company Contributions 9.0 0.1 — — Participant Contributions — — 2.4 2.2 Benefit Payments (27.2) (23.7) (7.7) (6.6) Fair Value of Plan Assets as of December 31, $ 326.9 $ 296.9 $ 129.9 $ 117.2 Funded (Underfunded) Status as of December 31, $ (7.6) $ (17.3) $ 52.8 $ 39.8 Pension Plans OPEB December 31, SWEPCo 2020 2019 2020 2019 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ — $ — $ 52.8 $ 39.8 Other Current Liabilities – Accrued Short-term Benefit Liability (0.1) (0.1) — — Employee Benefits and Pension Obligations – Accrued Long-term Benefit Liability (7.5) (17.2) — — Funded (Underfunded) Status $ (7.6) $ (17.3) $ 52.8 $ 39.8 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, 2020 2019 2020 2019 Components (in millions) Net Actuarial Loss $ 1,179.6 $ 1,406.2 $ 101.9 $ 225.8 Prior Service Cost (Credit) 0.2 0.2 (227.3) (285.7) Recorded as Regulatory Assets $ 1,182.4 $ 1,351.8 $ (99.0) $ (46.8) Deferred Income Taxes (0.5) 11.5 (5.5) (2.7) Net of Tax AOCI (2.1) 43.1 (20.9) (10.4) AEP Pension Plans OPEB 2020 2019 2020 2019 Components (in millions) Actuarial (Gain) Loss During the Year $ (132.9) $ 108.6 $ (118.0) $ (171.9) Amortization of Actuarial Loss (93.7) (57.6) (5.9) (22.1) Prior Service (Credit) Cost — 0.2 (11.4) (7.6) Amortization of Prior Service Credit — — 69.8 69.1 Change for the Year Ended December 31, $ (226.6) $ 51.2 $ (65.5) $ (132.5) AEP Texas Pension Plans OPEB December 31, 2020 2019 2020 2019 Components (in millions) Net Actuarial Loss $ 160.5 $ 184.7 $ 12.3 $ 23.5 Prior Service Credit — — (19.3) (24.2) Recorded as Regulatory Assets $ 151.3 $ 172.2 $ (6.3) $ (0.2) Deferred Income Taxes 2.0 2.7 (0.1) (0.1) Net of Tax AOCI 7.2 9.8 (0.6) (0.4) AEP Texas Pension Plans OPEB 2020 2019 2020 2019 Components (in millions) Actuarial (Gain) Loss During the Year $ (16.4) $ 7.6 $ (10.7) $ (12.7) Amortization of Actuarial Loss (7.8) (4.9) (0.5) (1.8) Prior Service Credit — — (1.0) (0.6) Amortization of Prior Service Credit — — 5.9 5.9 Change for the Year Ended December 31, $ (24.2) $ 2.7 $ (6.3) $ (9.2) APCo Pension Plans OPEB December 31, 2020 2019 2020 2019 Components (in millions) Net Actuarial Loss $ 126.3 $ 168.3 $ 11.1 $ 28.8 Prior Service Credit — — (33.2) (41.6) Recorded as Regulatory Assets $ 124.7 $ 166.3 $ (10.3) $ (5.5) Deferred Income Taxes 0.3 0.3 (2.5) (1.5) Net of Tax AOCI 1.3 1.7 (9.3) (5.8) APCo Pension Plans OPEB 2020 2019 2020 2019 Components (in millions) Actuarial (Gain) Loss During the Year $ (30.8) $ 3.1 $ (16.8) $ (26.4) Amortization of Actuarial Loss (11.2) (7.0) (0.9) (3.7) Prior Service Credit — — (1.8) (1.3) Amortization of Prior Service Credit — — 10.2 10.1 Change for the Year Ended December 31, $ (42.0) $ (3.9) $ (9.3) $ (21.3) I&M Pension Plans OPEB December 31, 2020 2019 2020 2019 Components (in millions) Net Actuarial Loss $ 39.5 $ 76.0 $ 15.6 $ 32.7 Prior Service Credit — — (31.0) (39.0) Recorded as Regulatory Assets $ 40.3 $ 73.7 $ (14.6) $ (6.2) Deferred Income Taxes (0.1) 0.5 (0.2) — Net of Tax AOCI (0.7) 1.8 (0.6) (0.1) I&M Pension Plans OPEB 2020 2019 2020 2019 Components (in millions) Actuarial (Gain) Loss During the Year $ (25.7) $ 2.0 $ (16.4) $ (19.3) Amortization of Actuarial Loss (10.8) (6.6) (0.7) (2.7) Prior Service Credit — — (1.5) (1.0) Amortization of Prior Service Credit — — 9.5 9.4 Change for the Year Ended December 31, $ (36.5) $ (4.6) $ (9.1) $ (13.6) OPCo Pension Plans OPEB December 31, 2020 2019 2020 2019 Components (in millions) Net Actuarial Loss $ 150.0 $ 178.7 $ 3.6 $ 17.2 Prior Service Credit — — (22.9) (28.6) Recorded as Regulatory Assets $ 150.0 $ 178.7 $ (19.3) $ (11.4) OPCo Pension Plans OPEB 2020 2019 2020 2019 Components (in millions) Actuarial (Gain) Loss During the Year $ (20.2) $ 3.3 $ (12.9) $ (15.8) Amortization of Actuarial Loss (8.5) (5.3) (0.7) (2.5) Prior Service Credit — — (1.3) (0.8) Amortization of Prior Service Credit — — 7.0 6.9 Change for the Year Ended December 31, $ (28.7) $ (2.0) $ (7.9) $ (12.2) PSO Pension Plans OPEB December 31, 2020 2019 2020 2019 Components (in millions) Net Actuarial Loss $ 55.9 $ 73.0 $ 10.5 $ 18.2 Prior Service Credit — — (14.1) (17.8) Recorded as Regulatory Assets $ 55.9 $ 73.0 $ (3.6) $ 0.4 PSO Pension Plans OPEB 2020 2019 2020 2019 Components (in millions) Actuarial Gain During the Year $ (12.4) $ (1.7) $ (7.4) $ (8.9) Amortization of Actuarial Loss (4.7) (2.9) (0.3) (1.2) Prior Service Credit — — (0.7) (0.5) Amortization of Prior Service Credit — — 4.4 4.3 Change for the Year Ended December 31, $ (17.1) $ (4.6) $ (4.0) $ (6.3) SWEPCo Pension Plans OPEB December 31, 2020 2019 2020 2019 Components (in millions) Net Actuarial Loss $ 86.9 $ 97.8 $ 11.5 $ 21.1 Prior Service Credit — — (17.2) (21.6) Recorded as Regulatory Assets $ 86.9 $ 97.8 $ (3.0) $ — Deferred Income Taxes — — (0.5) — Net of Tax AOCI — — (2.2) (0.5) SWEPCo Pension Plans OPEB 2020 2019 2020 2019 Components (in millions) Actuarial (Gain) Loss During the Year $ (5.2) $ 3.8 $ (9.2) $ (11.4) Amortization of Actuarial Loss (5.7) (3.4) (0.4) (1.4) Prior Service Credit — — (0.8) (0.6) Amortization of Prior Service Credit — — 5.2 5.2 Change for the Year Ended December 31, $ (10.9) $ 0.4 $ (5.2) $ (8.2) 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 2020 2019 2020 2019 AEP Texas 8.5 % 8.7 % 8.3 % 8.3 % APCo 12.6 % 12.7 % 15.1 % 15.2 % I&M 12.6 % 12.6 % 12.2 % 12.1 % OPCo 9.8 % 10.0 % 10.9 % 11.1 % PSO 5.4 % 5.5 % 5.5 % 5.5 % SWEPCo 5.9 % 5.9 % 6.7 % 6.6 % The following table presents the classification of pension plan assets for AEP within the fair value hierarchy as of December 31, 2020: Asset Class Level 1 Level 2 Level 3 Other Total Year End (in millions) Equities (a): Domestic $ 542.3 $ — $ — $ — $ 542.3 9.7 % International 676.3 — — — 676.3 12.2 % Common Collective Trusts (c) — — — 650.0 650.0 11.7 % Subtotal – Equities 1,218.6 — — 650.0 1,868.6 33.6 % Fixed Income (a): United States Government and Agency Securities (1.4) 1,134.1 — — 1,132.7 20.4 % Corporate Debt — 1,425.0 — — 1,425.0 25.6 % Foreign Debt — 214.0 — — 214.0 3.9 % State and Local Government — 56.0 — — 56.0 1.0 % Other – Asset Backed — 0.8 — — 0.8 — % Subtotal – Fixed Income (1.4) 2,829.9 — — 2,828.5 50.9 % Infrastructure (c) — — — 91.1 91.1 1.6 % Real Estate (c) — — — 231.6 231.6 4.2 % Alternative Investments (c) — — — 431.8 431.8 7.8 % Cash and Cash Equivalents (c) — 49.3 — 58.2 107.5 1.9 % Other – Pending Transactions and Accrued Income (b) — — — (2.5) (2.5) — % Total $ 1,217.2 $ 2,879.2 $ — $ 1,460.2 $ 5,556.6 100.0 % (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, 2020: Asset Class Level 1 Level 2 Level 3 Other Total Year End (in millions) Equities: Domestic $ 399.9 $ — $ — $ — $ 399.9 20.6 % International 290.7 — — — 290.7 14.9 % Common Collective Trusts (b) — — — 264.7 264.7 13.6 % Subtotal – Equities 690.6 — — 264.7 955.3 49.1 % Fixed Income: Common Collective Trust – Debt (b) — — — 186.4 186.4 9.6 % United States Government and Agency Securities (0.2) 199.7 — — 199.5 10.2 % Corporate Debt — 248.7 — — 248.7 12.8 % Foreign Debt — 34.9 — — 34.9 1.8 % State and Local Government 73.9 13.1 — — 87.0 4.5 % Subtotal – Fixed Income 73.7 496.4 — 186.4 756.5 38.9 % Trust Owned Life Insurance: International Equities — 64.8 — — 64.8 3.3 % United States Bonds — 135.9 — — 135.9 7.0 % Subtotal – Trust Owned Life Insurance — 200.7 — — 200.7 10.3 % Cash and Cash Equivalents (b) 26.3 — — 5.7 32.0 1.6 % Other – Pending Transactions and Accrued Income (a) — — — 2.2 2.2 0.1 % Total $ 790.6 $ 697.1 $ — $ 459.0 $ 1,946.7 100.0 % (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, 2019: Asset Class Level 1 Level 2 Level 3 Other Total Year End (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 (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. 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 $ 5,171.3 $ 424.5 $ 645.8 $ 615.8 $ 479.2 $ 258.3 $ 307.1 Nonqualified Pension Plans 72.9 3.6 0.2 0.8 0.2 1.6 1.4 Total as of December 31, 2020 $ 5,244.2 $ 428.1 $ 646.0 $ 616.6 $ 479.4 $ 259.9 $ 308.5 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 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 $ 81.4 $ 3.9 $ 0.5 $ 1.7 $ 0.6 $ 2.0 $ 334.5 Fair Value of Plan Assets — — — — — — 326.9 Underfunded Projected Benefit Obligation as of December 31, 2020 $ (81.4) $ (3.9) $ (0.5) $ (1.7) $ (0.6) $ (2.0) $ (7.6) 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) Accumulated Benefit Obligation AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Accumulated Benefit Obligation $ 72.9 $ 3.6 $ 0.2 $ 0.8 $ 0.2 $ 1.6 $ 1.4 Fair Value of Plan Assets — — — — — — — Underfunded Accumulated Benefit Obligation as of December 31, 2020 $ (72.9) $ (3.6) $ (0.2) $ (0.8) $ (0.2) $ (1.6) $ (1.4) 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) 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 non-qualified 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 2021: Company Pension Plans OPEB (in millions) AEP $ 132.8 $ 3.1 AEP Texas 5.1 0.1 APCo 1.8 1.8 I&M 1.3 — PSO 0.1 — SWEPCo 7.1 — 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) 2021 $ 385.3 $ 36.3 $ 44.7 $ 40.2 $ 35.4 $ 21.8 $ 25.2 2022 382.8 35.9 45.1 42.4 36.0 21.2 25.4 2023 384.3 36.1 45.1 41.5 34.2 22.3 25.7 2024 384.0 35.9 45.7 42.7 34.0 21.9 25.7 2025 377.1 35.2 44.0 42.7 33.3 21.1 25.3 Years 2026 to 2030, in Total 1,763.1 154.1 209.7 205.2 155.0 94.8 115.7 OPEB Benefit Payments AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) 2021 $ 121.6 $ 9.5 $ 21.1 $ 15.1 $ 13.7 $ 6.4 $ 7.5 2022 122.5 9.9 20.8 15.3 13.9 6.7 7.8 2023 117.4 9.7 19.8 14.7 13.2 6.6 7.6 2024 121.9 10.3 20.5 15.3 13.7 6.9 8.2 2025 120.9 10.4 20.0 15.1 13.4 6.9 8.2 Years 2026 to 2030, in Total 573.9 48.6 93.3 70.9 61.7 32.1 39.1 OPEB Medicare AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) 2021 $ 0.2 $ — $ 0.1 $ — $ — $ — $ — 2022 0.2 — 0.1 — — — — 2023 0.3 — 0.1 — — — — 2024 0.3 — 0.1 — — — — 2025 0.3 — 0.1 — — — — Years 2026 to 2030, in Total 1.5 — 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, 2020 2019 2018 2020 2019 2018 (in millions) Service Cost $ 111.9 $ 95.5 $ 97.6 $ 10.0 $ 9.5 $ 11.6 Interest Cost 167.9 204.4 187.8 39.8 50.5 47.4 Expected Return on Plan Assets (264.9) (296.0) (290.3) (95.6

Business Segments

Business Segments	12 Months Ended
	Dec. 31, 2020
Business Segments	9. 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 to serve standard service offer 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. • Marketing, risk management and retail activities in ERCOT, MISO, PJM and SPP. • Competitive generation in PJM. 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 and 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, 2020, 2019 and 2018 and reportable segment balance sheet information as of December 31, 2020 and 2019. Vertically Integrated Utilities Transmission and Distribution Utilities AEP Transmission Holdco Generation & Marketing Corporate and Other (a) Reconciling Adjustments Consolidated (in millions) 2020 Revenues from: External Customers $ 8,753.2 $ 4,238.7 $ 297.4 $ 1,621.0 $ 8.2 $ — $ 14,918.5 Other Operating Segments 126.2 107.2 901.4 104.6 88.6 (1,328.0) — Total Revenues $ 8,879.4 $ 4,345.9 $ 1,198.8 $ 1,725.6 $ 96.8 $ (1,328.0) $ 14,918.5 Depreciation and Amortization $ 1,600.5 $ 751.1 $ 257.6 $ 72.8 $ 0.8 $ — $ 2,682.8 Interest Expense 565.0 289.2 133.2 24.0 196.4 (42.1) 1,165.7 Income Tax Expense (Benefit) (7.0) 29.7 130.8 (108.0) (5.0) — 40.5 Equity Earnings of Unconsolidated Subsidiaries 2.9 — 82.4 3.2 2.6 — 91.1 Net Income (Loss) $ 1,064.5 $ 496.4 $ 508.5 $ 216.9 $ (89.6) $ — $ 2,196.7 Gross Property Additions $ 2,291.2 $ 2,108.1 $ 1,649.3 $ 197.0 $ 16.0 $ (15.3) $ 6,246.3 Total Property, Plant and Equipment $ 49,023.3 $ 21,145.0 $ 11,827.2 $ 1,910.2 $ 407.3 $ — $ 84,313.0 Accumulated Depreciation and Amortization 15,586.2 3,879.3 595.7 166.1 184.1 — 20,411.4 Total Property, Plant and Equipment – Net $ 33,437.1 $ 17,265.7 $ 11,231.5 $ 1,744.1 $ 223.2 $ — $ 63,901.6 Total Assets $ 42,752.7 $ 19,765.9 $ 12,627.3 $ 3,585.9 $ 5,987.1 (b) $ (3,961.7) (c) $ 80,757.2 Investments in Equity Method Investees $ 37.1 $ 2.1 $ 831.3 $ 467.0 $ 68.8 $ — $ 1,406.3 Long-term Debt Due Within One Year: Nonaffiliated $ 1,034.6 $ 588.8 $ 52.3 $ — $ 410.4 (d) $ — $ 2,086.1 Long-term Debt: Affiliated 65.0 — — — — (65.0) — Nonaffiliated 12,375.6 6,661.9 4,075.7 — 5,873.2 (d) — 28,986.4 Total Long-term Debt $ 13,475.2 $ 7,250.7 $ 4,128.0 $ — $ 6,283.6 $ (65.0) $ 31,072.5 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 (e) 2,514.5 Interest Expense 568.3 243.3 103.3 30.0 193.7 (66.1) (e) 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) (e) $ 79,145.7 Accumulated Depreciation and Amortization 14,580.4 3,911.2 418.9 99.0 184.5 (186.4) (e) 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) (e) $ 60,138.1 Total Assets $ 41,228.8 $ 18,757.5 $ 11,143.5 $ 3,123.8 $ 5,440.0 (b) $ (3,801.3) (c)(e) $ 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 (d) — 1,598.7 Long-term Debt: Affiliated 39.0 — — — — (39.0) — Nonaffiliated 12,162.0 6,248.1 3,593.8 — 3,122.9 — 25,126.8 Total Long-term Debt $ 12,925.7 $ 6,640.3 $ 3,593.8 $ — $ 3,624.7 (d) $ (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 (e) 2,286.6 Interest Expense 567.8 248.1 90.7 14.9 122.6 (59.7) (e) 984.4 Income Tax Expense 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 Assets $ 38,874.3 $ 17,083.4 $ 9,543.7 $ 1,979.7 $ 4,036.5 (b) $ (2,714.8) (c)(e) $ 68,802.8 (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 elimination of AEP Parent’s investments in wholly-owned subsidiary companies. (c) Reconciling Adjustments for Total Assets primarily include elimination of intercompany advances to affiliates and intercompany accounts receivable. (d) Amounts reflect the impact of fair value hedge accounting. See “Accounting for Fair Value Hedging Strategies” section of Note 10 for additional information. (e) Includes eliminations due to an intercompany finance lease. 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, 2020, 2019 and 2018 and reportable segment balance sheet information as of December 31, 2020 and 2019. State Transcos AEPTCo Parent Reconciling Adjustments AEPTCo 2020 (in millions) Revenues from: External Customers $ 248.8 $ — $ — $ 248.8 Sales to AEP Affiliates 896.3 — — 896.3 Other Revenues 0.6 — — 0.6 Total Revenues $ 1,145.7 $ — $ — $ 1,145.7 Depreciation and Amortization $ 249.0 $ — $ — $ 249.0 Interest Income 0.9 149.6 (148.1) (a) 2.4 Allowance for Equity Funds Used During Construction 74.0 — — 74.0 Interest Expense 127.8 148.1 (148.1) (a) 127.8 Income Tax Expense 106.5 0.2 — 106.7 Net Income $ 422.3 $ 1.1 (b) $ — $ 423.4 Gross Property Additions $ 1,621.9 $ — $ — $ 1,621.9 Total Transmission Property $ 11,345.6 $ — $ — $ 11,345.6 Accumulated Depreciation and Amortization 572.8 — — 572.8 Total Transmission Property - Net $ 10,772.8 $ — $ — $ 10,772.8 Notes Receivable - Affiliated $ — $ 3,948.5 $ (3,948.5) (c) $ — Total Assets $ 11,185.1 $ 4,084.0 (d) $ (4,023.1) (e) $ 11,246.0 Total Long-Term Debt $ 3,990.0 $ 3,948.5 $ (3,990.0) (c) $ 3,948.5 State Transcos AEPTCo Parent Reconciling Adjustments AEPTCo 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 2018 (in millions) Revenues from: External Customers $ 177.0 $ — $ — $ 177.0 Sales to AEP Affiliates 598.9 — — 598.9 Other 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 Assets $ 8,406.8 $ 2,857.1 (d) $ (2,869.8) (e) $ 8,394.1 (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, 2020
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: December 31, 2020 Primary Risk Unit of AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Commodity: Power MWhs 331.3 — 46.9 19.7 3.0 11.9 4.0 Natural Gas MMBtus 26.9 — — — — — 7.9 Heating Oil and Gasoline Gallons 6.9 1.8 1.1 0.6 1.4 0.7 0.9 Interest Rate USD $ 129.8 $ — $ — $ — $ — $ — $ — Interest Rate on Long-term Debt USD $ 1,150.0 $ — $ 200.0 $ — $ — $ — $ — December 31, 2019 Primary Risk Unit of 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 $ — $ — $ — $ — $ — $ — 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 and other 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 $3 million and $5 million as of December 31, 2020 and 2019, respectively. AEP netted cash collateral paid to third-parties against short-term and long-term risk management liabilities in the amounts of $7 million and $39 million as of December 31, 2020 and 2019, 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 Registrant Subsidiaries as of December 31, 2020 and 2019. The following tables represent the gross fair value of the Registrants’ derivative activity on the balance sheets: AEP December 31, 2020 Risk Hedging Contracts Gross Amounts Gross Net Amounts of Balance Sheet Location Commodity (a) Commodity (a) Interest Rate (a) (in millions) Current Risk Management Assets $ 239.1 $ 21.1 $ 5.0 $ 265.2 $ (170.5) $ 94.7 Long-term Risk Management Assets 275.9 18.0 — 293.9 (51.7) 242.2 Total Assets 515.0 39.1 5.0 559.1 (222.2) 336.9 Current Risk Management Liabilities 193.0 54.4 3.4 250.8 (172.0) 78.8 Long-term Risk Management Liabilities 222.2 60.1 4.1 286.4 (53.6) 232.8 Total Liabilities 415.2 114.5 7.5 537.2 (225.6) 311.6 Total MTM Derivative Contract Net Assets (Liabilities) $ 99.8 $ (75.4) $ (2.5) $ 21.9 $ 3.4 $ 25.3 December 31, 2019 Risk Hedging Contracts Gross Amounts Gross Net Amounts of 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 AEP Texas December 31, 2020 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 $ 0.4 $ (0.4) $ — Long-term Risk Management Assets — — — Total Assets 0.4 (0.4) — Current Risk Management Liabilities — — — Long-term Risk Management Liabilities — — — Total Liabilities — — — Total MTM Derivative Net Assets (Liabilities) $ 0.4 $ (0.4) $ — 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 $ — $ — $ — APCo December 31, 2020 Risk Gross Amounts of Risk Gross Amounts Net Amounts of Assets/ Management Hedging Management Offset in the Liabilities Presented in Contracts - Contracts - Assets/Liabilities Statement of the Statement of Balance Sheet Location Commodity (a) Interest Rate (a) Recognized Financial Position (b) Financial Position (c) (in millions) Current Risk Management Assets $ 38.8 $ 2.4 $ 41.2 $ (18.8) $ 22.4 Deferred Charges and Other Noncurrent Assets - Long-term Risk Management Assets 0.7 — 0.7 (0.6) 0.1 Total Assets 39.5 2.4 41.9 (19.4) 22.5 Current Risk Management Liabilities 19.7 3.4 23.1 (18.5) 4.6 Deferred Credits and Other Noncurrent Liabilities - Long-term Risk Management Liabilities 0.6 — 0.6 (0.5) 0.1 Total Liabilities 20.3 3.4 23.7 (19.0) 4.7 Total MTM Derivative Contract Net Assets (Liabilities) $ 19.2 $ (1.0) $ 18.2 $ (0.4) $ 17.8 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 Deferred Charges and Other Noncurrent Assets - 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 Deferred Credits and Other Noncurrent Liabilities - 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 I&M December 31, 2020 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 $ 17.2 $ (13.6) $ 3.6 Deferred Charges and Other Noncurrent Assets - Long-term Risk Management Assets 0.5 (0.4) 0.1 Total Assets 17.7 (14.0) 3.7 Other Current Liabilities - Current Risk Management Liabilities 12.1 (12.0) 0.1 Deferred Credits and Other Noncurrent Liabilities - Long-term Risk Management Liabilities 0.4 (0.3) 0.1 Total Liabilities 12.5 (12.3) 0.2 Total MTM Derivative Contract Net Assets (Liabilities) $ 5.2 $ (1.7) $ 3.5 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 Deferred Charges and Other Noncurrent Assets - Long-term Risk Management Assets 0.5 (0.4) 0.1 Total Assets 67.4 (57.5) 9.9 Other Current Liabilities - Current Risk Management Liabilities 55.2 (54.7) 0.5 Deferred Credits and Other Noncurrent Liabilities - 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 OPCo December 31, 2020 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 $ 0.3 $ (0.3) $ — Long-term Risk Management Assets — — — Total Assets 0.3 (0.3) — Current Risk Management Liabilities 8.7 — 8.7 Long-term Risk Management Liabilities 101.6 — 101.6 Total Liabilities 110.3 — 110.3 Total MTM Derivative Contract Net Liabilities $ (110.0) $ (0.3) $ (110.3) 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) PSO December 31, 2020 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 $ 10.5 $ (0.2) $ 10.3 Long-term Risk Management Assets — — — Total Assets 10.5 (0.2) 10.3 Current Risk Management Liabilities — — — Long-term Risk Management Liabilities — — — Total Liabilities — — — Total MTM Derivative Net Assets (Liabilities) $ 10.5 $ (0.2) $ 10.3 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 SWEPCo December 31, 2020 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 $ 3.4 $ (0.2) $ 3.2 Long-term Risk Management Assets — — — Total Assets 3.4 (0.2) 3.2 Current Risk Management Liabilities 0.7 — 0.7 Long-term Risk Management Liabilities 1.0 — 1.0 Total Liabilities 1.7 — 1.7 Total MTM Derivative Net Assets (Liabilities) $ 1.7 $ (0.2) $ 1.5 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 (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’ amount of gain (loss) recognized on risk management contracts: Year Ended December 31, 2020 Location of Gain (Loss) AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Vertically Integrated Utilities Revenues $ 0.8 $ — $ — $ — $ — $ — $ — Generation & Marketing Revenues 9.5 — — — — — — Electric Generation, Transmission and Distribution Revenues — — 0.4 0.1 — — 0.1 Purchased Electricity for Resale 1.4 — 1.2 0.1 — — — Other Operation (2.0) (0.6) (0.2) (0.2) (0.3) (0.2) (0.3) Maintenance (2.9) (0.8) (0.4) (0.3) (0.5) (0.3) (0.4) Regulatory Assets (a) (4.8) — — (0.1) (6.6) — 1.4 Regulatory Liabilities (a) 114.9 0.4 20.3 12.4 12.4 39.1 20.2 Total Gain (Loss) on Risk Management Contracts $ 116.9 $ (1.0) $ 21.3 $ 12.0 $ 5.0 $ 38.6 $ 21.0 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 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 (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, 2020 December 31, 2019 December 31, 2020 December 31, 2019 (in millions) Long-term Debt (a) (b) $ (995.9) $ (510.8) $ (51.7) $ (14.5) (a) Amounts included on the balance sheets within Long-term Debt Due within One Year and Long-term Debt, respectively. (b) Amounts include $(53) million and $0 as of December 31, 2020 and 2019, respectively, for the fair value hedge adjustment of hedged debt obligations for which hedge accounting has been discontinued. The pretax effects of fair value hedge accounting on income were as follows: Years Ended December 31, 2020 2019 2018 (in millions) Gain (Loss) on Interest Rate Contracts: Fair Value Hedging Instruments (a) $ 41.1 $ 31.9 $ (11.3) Fair Value Portion of Long-term Debt (a) (41.1) (31.9) 11.3 (a) Gain (Loss) is included in Interest Expense on the statements of income. In June 2020, AEP terminated a $500 million notional amount interest rate swap resulting in the discontinuance of the hedging relationship. A gain of $57 million on the fair value of the hedging instrument was settled in cash and recorded within operating activities on the statement of cash flows. Subsequent to the discontinuation of hedge accounting, the remaining adjustment to the carrying amount of the hedged item of $57 million will be amortized on a straight-line basis through November 2027 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 2020, 2019 and 2018, AEP applied cash flow hedging to outstanding power derivatives. During the years ended 2020, 2019 and 2018, 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 2020, 2019 and 2018, AEP applied cash flow hedging to outstanding interest rate derivatives. During the year ended 2020, APCo applied cash flow hedging to outstanding interest rate derivatives and the other Registrant Subsidiaries did not. During the year ended 2019, 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, 2020 December 31, 2019 Commodity Interest Rate Commodity Interest Rate (in millions) AOCI Gain (Loss) Net of Tax $ (60.6) $ (47.5) $ (103.5) $ (11.5) Portion Expected to be Reclassed to Net Income During the Next Twelve Months (27.1) (5.7) (51.7) (2.1) As of December 31, 2020 the maximum length of time that AEP is hedging its exposure to variability in future cash flows related to forecasted transactions is 123 months and 120 months for commodity and interest rate hedges, respectively. Impact of Cash Flow Hedges on the Registrant Subsidiaries’ Balance Sheets December 31, 2020 December 31, 2019 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 $ (2.3) $ (1.1) $ (3.4) $ (1.1) APCo (0.8) 0.4 0.9 0.9 I&M (8.3) (1.6) (9.9) (1.6) PSO 0.1 0.1 1.1 1.0 SWEPCo (0.3) (1.5) (1.8) (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, surety bonds 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, 2020 and 2019. 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, 2020 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 $ 188.4 $ — $ 169.2 APCo 4.3 — 3.5 I&M 0.5 — 0.1 SWEPCo 1.8 — 1.8 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 Warrants Held in Investee (Applies to AEP) As of December 31, 2020, AEP held an $8 million investment in a privately held investee that is anticipated to complete an initial public offering (IPO) in the first quarter of 2021 . The IPO is expected to be completed via a reverse merger with a public special purpose acquisition company. AEP’s interests in the investee as of December 31, 2020 consisted of a noncontrolling equity interest of preferred shares, which were accounted for at historical cost until completion of the IPO, and common share warrants, which management has determined are derivative instruments based on the accounting guidance for “Derivatives and Hedging”. As of December 31, 2020, the warrants were valued at $32 million and were recorded in Deferred Charges and Other Noncurrent Assets on AEP’s balance sheet. AEP recognized an unrealized gain of $32 million associated with the warrants for the year ended December 31, 2020, presented in Other Income on AEP’s statement of income. Management utilized a Black-Scholes options pricing model to value the warrants as of December 31, 2020. As the reverse merger and IPO did not close prior to the end of 2020, the valuation contemplated a liquidity adjustment that resulted in the overall fair value of the warrants being categorized as Level 3 in the fair value hierarchy. See “Fair Value Measurements of Financial Assets and Liabilities” section of Note 11 for additional information.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2020
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, 2020 2019 Company Book Value Fair Value Book Value Fair Value (in millions) AEP (a) $ 31,072.5 $ 37,457.0 $ 26,725.5 $ 30,172.0 AEP Texas 4,820.4 5,682.6 4,558.4 4,981.5 AEPTCo 3,948.5 4,984.3 3,427.3 3,868.0 APCo 4,834.1 6,391.8 4,363.8 5,253.1 I&M 3,029.9 3,775.3 3,050.2 3,453.8 OPCo 2,430.2 3,154.9 2,082.0 2,554.3 PSO 1,373.8 1,732.1 1,386.2 1,603.3 SWEPCo 2,636.4 3,210.1 2,655.6 2,927.9 (a) The fair value amounts include debt related to AEP’s Equity Units and had a fair value of $1.7 billion and $871 million as of December 31, 2020 and 2019, respectively. 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, 2020 Gross Gross Unrealized Unrealized Fair Other Temporary Investments Cost Gains Losses Value (in millions) Restricted Cash and Other Cash Deposits (a) $ 68.3 $ — $ — $ 68.3 Fixed Income Securities – Mutual Funds (b) 120.7 2.8 — 123.5 Equity Securities – Mutual Funds 25.9 28.7 — 54.6 Total Other Temporary Investments $ 214.9 $ 31.5 $ — $ 246.4 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 (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, 2020 2019 2018 (in millions) Proceeds from Investment Sales $ 50.9 $ 21.2 $ — Purchases of Investments 41.6 45.0 3.1 Gross Realized Gains on Investment Sales 3.8 — — Gross Realized Losses on Investment Sales 0.2 0.4 — 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 for additional information. The following is a summary of nuclear trust fund investments: December 31, 2020 2019 Gross Other-Than- Gross Other-Than- Fair Unrealized Temporary Fair Unrealized Temporary Value Gains Impairments Value Gains Impairments (in millions) Cash and Cash Equivalents $ 25.8 $ — $ — $ 15.3 $ — $ — Fixed Income Securities: United States Government 1,025.6 98.5 (7.1) 1,112.5 55.5 (6.1) Corporate Debt 86.3 9.6 (1.7) 72.4 5.3 (1.6) State and Local Government 114.3 0.9 (0.4) 7.6 0.7 (0.2) Subtotal Fixed Income Securities 1,226.2 109.0 (9.2) 1,192.5 61.5 (7.9) Equity Securities - Domestic (a) 2,054.7 1,400.8 — 1,767.9 1,144.4 — Spent Nuclear Fuel and Decommissioning Trusts $ 3,306.7 $ 1,509.8 $ (9.2) $ 2,975.7 $ 1,205.9 $ (7.9) (a) Amount reported as Gross Unrealized Gains includes unrealized gains of $1.4 billion and $1.1 billion and unrealized losses of $9 million and $5 million as of December 31, 2020 and 2019, respectively. The following table provides the securities activity within the decommissioning and SNF trusts: Years Ended December 31, 2020 2019 2018 (in millions) Proceeds from Investment Sales $ 1,593.4 $ 1,473.0 $ 2,010.0 Purchases of Investments 1,637.2 1,531.0 2,064.7 Gross Realized Gains on Investment Sales 26.4 76.5 47.5 Gross Realized Losses on Investment Sales 26.1 24.3 32.8 The base cost of fixed income securities was $1.1 billion and $1.1 billion as of December 31, 2020 and 2019, respectively. The base cost of equity securities was $654 million and $623 million as of December 31, 2020 and 2019, respectively. The fair value of fixed income securities held in the nuclear trust funds, summarized by contractual maturities, as of December 31, 2020 was as follows: Fair Value of Fixed Income Securities (in millions) Within 1 year $ 294.8 After 1 year through 5 years 371.3 After 5 years through 10 years 214.4 After 10 years 345.7 Total $ 1,226.2 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 December 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Other Temporary Investments Restricted Cash and Other Cash Deposits (a) $ 57.8 $ — $ — $ 10.5 $ 68.3 Fixed Income Securities – Mutual Funds 123.5 — — — 123.5 Equity Securities – Mutual Funds (b) 54.6 — — — 54.6 Total Other Temporary Investments 235.9 — — 10.5 246.4 Risk Management Assets Risk Management Commodity Contracts (c) (d) 0.9 258.8 252.4 (190.0) 322.1 Cash Flow Hedges: Commodity Hedges (c) — 34.4 3.9 (28.5) 9.8 Interest Rate Hedges — 2.4 — — 2.4 Fair Value Hedges — 2.6 — — 2.6 Total Risk Management Assets 0.9 298.2 256.3 (218.5) 336.9 Spent Nuclear Fuel and Decommissioning Trusts Cash and Cash Equivalents (e) 16.8 — — 9.0 25.8 Fixed Income Securities: United States Government — 1,025.6 — — 1,025.6 Corporate Debt — 86.3 — — 86.3 State and Local Government — 114.3 — — 114.3 Subtotal Fixed Income Securities — 1,226.2 — — 1,226.2 Equity Securities – Domestic (b) 2,054.7 — — — 2,054.7 Total Spent Nuclear Fuel and Decommissioning Trusts 2,071.5 1,226.2 — 9.0 3,306.7 Other Investments (h) — — 31.8 — 31.8 Total Assets $ 2,308.3 $ 1,524.4 $ 288.1 $ (199.0) $ 3,921.8 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (d) $ 0.9 $ 244.2 $ 167.2 $ (193.4) $ 218.9 Cash Flow Hedges: Commodity Hedges (c) — 106.1 7.6 (28.5) 85.2 Interest Rate Hedges — 3.4 — — 3.4 Fair Value Hedges — 4.1 — — 4.1 Total Risk Management Liabilities $ 0.9 $ 357.8 $ 174.8 $ (221.9) $ 311.6 AEP 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) (f) 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) (f) $ 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 Texas December 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 28.7 $ — $ — $ — $ 28.7 Risk Management Assets Risk Management Commodity Contracts (c) — 0.4 — (0.4) — Total Assets $ 28.7 $ 0.4 $ — $ (0.4) $ 28.7 December 31, 2019 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 154.7 $ — $ — $ — $ 154.7 APCo December 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 16.9 $ — $ — $ — $ 16.9 Risk Management Assets Risk Management Commodity Contracts (c) (g) — 19.4 19.9 (19.2) 20.1 Cash Flow Hedges: Interest Rate Hedges — 2.4 — — 2.4 Total Risk Management Assets — 21.8 19.9 (19.2) 22.5 Total Assets $ 16.9 $ 21.8 $ 19.9 $ (19.2) $ 39.4 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 19.5 $ 0.6 $ (18.8) $ 1.3 Cash Flow Hedges: Interest Rate Hedges — 3.4 — — 3.4 Total Risk Management Liabilities $ — $ 22.9 $ 0.6 $ (18.8) $ 4.7 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 I&M December 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ 15.1 $ 2.5 $ (13.9) $ 3.7 Spent Nuclear Fuel and Decommissioning Trusts Cash and Cash Equivalents (e) 16.8 — — 9.0 25.8 Fixed Income Securities: United States Government — 1,025.6 — — 1,025.6 Corporate Debt — 86.3 — — 86.3 State and Local Government — 114.3 — — 114.3 Subtotal Fixed Income Securities — 1,226.2 — — 1,226.2 Equity Securities - Domestic (b) 2,054.7 — — — 2,054.7 Total Spent Nuclear Fuel and Decommissioning Trusts 2,071.5 1,226.2 — 9.0 3,306.7 Total Assets $ 2,071.5 $ 1,241.3 $ 2.5 $ (4.9) $ 3,310.4 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 12.0 $ 0.4 $ (12.2) $ 0.2 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 OPCo December 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ 0.3 $ — $ (0.3) $ — Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ — $ 110.3 $ — $ 110.3 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 PSO December 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ 0.2 $ 10.3 $ (0.2) $ 10.3 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) $ — SWEPCo December 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ 0.1 $ 3.3 $ (0.2) $ 3.2 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ — $ 1.7 $ — $ 1.7 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 (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, 2020 maturities of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), were as follows: Level 2 matures $3 million in periods 2022-2024, $11 million in periods 2025-2026 and $1 million in periods 2027-2033; Level 3 matures $47 million in 2021, $37 million in periods 2022-2024, $14 million in periods 2025-2026 and $(13) million in periods 2027-2033. 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, 2019 maturities of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), were 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. (g) Substantially comprised of power contracts for the Registrant Subsidiaries. (h) See “Warrants Held in Investee” section of Note 10 for additional information. 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, 2020 AEP APCo I&M OPCo PSO SWEPCo (in millions) Balance as of December 31, 2019 $ 109.9 $ 37.7 $ 5.8 $ (103.6) $ 15.8 $ 1.4 Realized Gain (Loss) Included in Net Income (or Changes in Net Assets) (a) (b) 39.5 13.2 2.5 (1.6) 11.9 2.8 Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date (a) 35.3 — — — — — Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income (c) 13.8 — — — — — Settlements (113.1) (51.6) (8.6) 8.9 (27.6) (6.6) Transfers into Level 3 (d) (e) (3.8) — — — — — Transfers out of Level 3 (e) 5.6 0.7 0.4 — — — Changes in Fair Value Allocated to Regulated Jurisdictions (f) 26.1 19.3 2.0 (14.0) 10.2 4.0 Balance as of December 31, 2020 $ 113.3 $ 19.3 $ 2.1 $ (110.3) $ 10.3 $ 1.6 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 (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: AEP December 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input Low High Average (in millions) Energy Contracts $ 213.5 $ 169.7 Discounted Cash Flow Forward Market Price (a) (c) $ 5.33 $ 100.47 $ 32.73 Natural Gas Contracts — 1.7 Discounted Cash Flow Forward Market Price (b) (c) 2.18 2.77 2.40 FTRs 42.8 3.4 Discounted Cash Flow Forward Market Price (a) (c) (15.08) 9.66 0.19 Other Investments 31.8 — Black-Scholes Model Liquidity Adjustment (d) 10 % 20 % 15 % Total $ 288.1 $ 174.8 December 31, 2019 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 APCo December 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ 1.0 $ 0.6 Discounted Cash Flow Forward Market Price $ 10.84 $ 41.09 $ 25.08 FTRs 18.9 — Discounted Cash Flow Forward Market Price 0.04 5.61 1.13 Total $ 19.9 $ 0.6 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 I&M December 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ 0.6 $ 0.3 Discounted Cash Flow Forward Market Price $ 10.84 $ 41.09 $ 25.08 FTRs 1.9 0.1 Discounted Cash Flow Forward Market Price (1.96) 3.69 0.33 Total $ 2.5 $ 0.4 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 OPCo December 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ — $ 110.3 Discounted Cash Flow Forward Market Price $ 16.19 $ 46.98 $ 28.30 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 PSO December 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) FTRs $ 10.3 $ — Discounted Cash Flow Forward Market Price $ (6.93) $ 0.48 $ (1.93) 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) SWEPCo December 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input Low High Average (c) (in millions) Natural Gas Contracts $ — $ 1.7 Discounted Cash Flow Forward Market Price (b) $ 2.18 $ 2.77 $ 2.41 FTRs 3.3 — Discounted Cash Flow Forward Market Price (a) (6.93) 0.48 (1.93) Total $ 3.3 $ 1.7 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 (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. (d) Represents percentage discount applied to the publically available share price. 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, FTRs and Other Investments for the Registrants as of December 31, 2020 and 2019: Uncertainty of Fair Value Measurements Significant Unobservable Input Position Change in Input Impact on Fair Value Forward Market Price Buy Increase (Decrease) Higher (Lower) Forward Market Price Sell Increase (Decrease) Lower (Higher) Liquidity Adjustment Buy Increase (Decrease) Lower (Higher)

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
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, 2020 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Federal: Current $ (138.2) $ 5.2 $ 22.2 $ 21.4 $ 11.3 $ (26.6) $ (11.4) $ (13.6) Deferred 146.9 (15.4) 65.4 (27.1) (20.6) 74.0 8.3 19.6 Total Federal 8.7 (10.2) 87.6 (5.7) (9.3) 47.4 (3.1) 6.0 State and Local: Current (16.7) (0.1) 2.8 9.3 1.9 (5.4) 0.1 (8.2) Deferred 48.5 (0.9) 16.3 0.7 (0.1) 3.2 8.2 11.6 Total State and Local 31.8 (1.0) 19.1 10.0 1.8 (2.2) 8.3 3.4 Income Tax Expense (Benefit) $ 40.5 $ (11.2) $ 106.7 $ 4.3 $ (7.5) $ 45.2 $ 5.2 $ 9.4 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 (71.6) (24.7) 71.7 (126.1) (57.1) 40.6 (26.0) (10.0) 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 61.7 — 19.6 (0.6) 0.8 3.2 7.8 (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 122.0 (17.9) 82.3 (24.5) (48.8) (36.9) (36.7) (1.9) 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 (5.8) (0.1) 16.6 7.8 1.2 0.7 6.3 1.7 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 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, 2020 2019 2018 (in millions) Net Income $ 2,196.7 $ 1,919.8 $ 1,931.3 Less: Equity Earnings – Dolet Hills (2.9) (3.0) (2.7) Income Tax Expense (Benefit) 40.5 (12.9) 115.3 Pretax Income $ 2,234.3 $ 1,903.9 $ 2,043.9 Income Taxes on Pretax Income at Statutory Rate (21%) $ 469.2 $ 399.8 $ 429.2 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 26.5 20.4 24.6 Investment Tax Credit Amortization (18.8) (13.0) (20.4) Production Tax Credits (83.1) (59.6) (10.3) State and Local Income Taxes, Net 25.1 52.2 19.7 Removal Costs (18.6) (22.2) (18.6) AFUDC (32.5) (37.1) (29.4) Tax Reform Adjustments — — (10.9) Tax Reform Excess ADIT Reversal (268.2) (353.2) (257.2) CARES Act (48.0) — — Other (11.1) (0.2) (11.4) Income Tax Expense (Benefit) $ 40.5 $ (12.9) $ 115.3 Effective Income Tax Rate 1.8 % (0.7) % 5.6 % AEP Texas Years Ended December 31, 2020 2019 2018 (in millions) Net Income $ 241.0 $ 178.3 $ 211.3 Income Tax Expense (Benefit) (11.2) (53.6) 20.8 Pretax Income $ 229.8 $ 124.7 $ 232.1 Income Taxes on Pretax Income at Statutory Rate (21%) $ 48.3 $ 26.2 $ 48.7 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 1.0 1.0 0.7 Investment Tax Credit Amortization (1.1) (1.2) (2.3) State and Local Income Taxes, Net (0.8) 2.3 1.3 AFUDC (4.1) (3.2) (4.2) Parent Company Loss Benefit (4.5) (3.8) (3.0) Tax Reform Adjustments — — (11.0) Tax Reform Excess ADIT Reversal (47.9) (73.4) (11.8) Other (2.1) (1.5) 2.4 Income Tax Expense (Benefit) $ (11.2) $ (53.6) $ 20.8 Effective Income Tax Rate (4.9) % (43.0) % 9.0 % AEPTCo Years Ended December 31, 2020 2019 2018 (in millions) Net Income $ 423.4 $ 439.7 $ 315.9 Income Tax Expense 106.7 117.4 84.1 Pretax Income $ 530.1 $ 557.1 $ 400.0 Income Taxes on Pretax Income at Statutory Rate (21%) $ 111.3 $ 117.0 $ 84.0 Increase (Decrease) in Income Taxes Resulting from the Following Items: State and Local Income Taxes, Net 15.1 17.4 12.6 AFUDC (15.5) (17.7) (14.1) Parent Company Loss Benefit (7.0) (4.2) (0.6) Other 2.8 4.9 2.2 Income Tax Expense $ 106.7 $ 117.4 $ 84.1 Effective Income Tax Rate 20.1 % 21.1 % 21.0 % APCo Years Ended December 31, 2020 2019 2018 (in millions) Net Income $ 369.7 $ 306.3 $ 367.8 Income Tax Expense (Benefit) 4.3 (78.0) (44.9) Pretax Income $ 374.0 $ 228.3 $ 322.9 Income Taxes on Pretax Income at Statutory Rate (21%) $ 78.5 $ 47.9 $ 67.8 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 12.7 10.8 9.4 State and Local Income Taxes, Net 7.9 9.0 9.1 Removal Costs (5.7) (6.4) (7.9) AFUDC (4.5) (5.2) (4.3) Parent Company Loss Benefit (6.2) (4.1) (3.6) Tax Reform Excess ADIT Reversal (72.3) (130.4) (108.5) Federal Return to Provision (7.2) (1.0) (6.6) Other 1.1 1.4 (0.3) Income Tax Expense (Benefit) $ 4.3 $ (78.0) $ (44.9) Effective Income Tax Rate 1.1 % (34.2) % (13.9) % I&M Years Ended December 31, 2020 2019 2018 (in millions) Net Income $ 284.8 $ 269.4 $ 261.3 Income Tax Expense (Benefit) (7.5) (10.6) 29.1 Pretax Income $ 277.3 $ 258.8 $ 290.4 Income Taxes on Pretax Income at Statutory Rate (21%) $ 58.2 $ 54.3 $ 61.0 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 1.6 4.0 1.5 Investment Tax Credit Amortization (4.5) (3.6) (4.7) State and Local Income Taxes, Net 1.5 (1.2) 13.4 Removal Costs (10.5) (12.8) (8.0) AFUDC (2.4) (4.1) (2.5) Parent Company Loss Benefit (6.4) (3.3) (2.3) Tax Reform Excess ADIT Reversal (46.8) (42.5) (25.8) Federal Return to Provision 1.9 (0.3) (4.6) Other (0.1) (1.1) 1.1 Income Tax Expense (Benefit) $ (7.5) $ (10.6) $ 29.1 Effective Income Tax Rate (2.7) % (4.1) % 10.0 % OPCo Years Ended December 31, 2020 2019 2018 (in millions) Net Income $ 271.4 $ 297.1 $ 325.5 Income Tax Expense 45.2 34.9 24.0 Pretax Income $ 316.6 $ 332.0 $ 349.5 Income Taxes on Pretax Income at Statutory Rate (21%) $ 66.5 $ 69.7 $ 73.4 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 3.7 (1.4) 2.4 State and Local Income Taxes, Net (1.7) 3.4 4.2 AFUDC (2.6) (3.8) (2.1) Parent Company Loss Benefit — (1.8) (6.0) Tax Reform Excess ADIT Reversal (27.2) (27.3) (51.0) Federal Return to Provision 6.5 (3.7) 0.2 Other — (0.2) 2.9 Income Tax Expense $ 45.2 $ 34.9 $ 24.0 Effective Income Tax Rate 14.3 % 10.5 % 6.9 % PSO Years Ended December 31, 2020 2019 2018 (in millions) Net Income $ 123.0 $ 137.6 $ 83.2 Income Tax Expense 5.2 7.5 5.0 Pretax Income $ 128.2 $ 145.1 $ 88.2 Income Taxes on Pretax Income at Statutory Rate (21%) $ 26.9 $ 30.5 $ 18.5 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 1.1 0.6 0.7 Investment Tax Credit Amortization (2.1) (0.5) (1.7) State and Local Income Taxes, Net 6.5 6.3 4.8 Parent Company Loss Benefit (0.2) (2.1) (1.4) Tax Reform Excess ADIT Reversal (25.5) (24.5) (15.5) Other (1.5) (2.8) (0.4) Income Tax Expense $ 5.2 $ 7.5 $ 5.0 Effective Income Tax Rate 4.1 % 5.2 % 5.7 % SWEPCo Years Ended December 31, 2020 2019 2018 (in millions) Net Income $ 183.7 $ 162.2 $ 152.2 Less: Equity Earnings – Dolet Hills (2.9) (3.0) (2.7) Income Tax Expense (Benefit) 9.4 (4.7) 20.4 Pretax Income $ 190.2 $ 154.5 $ 169.9 Income Taxes on Pretax Income at Statutory Rate (21%) $ 39.9 $ 32.4 $ 35.7 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 1.9 1.9 1.9 Depletion (3.4) (3.4) (3.4) State and Local Income Taxes, Net 2.7 (1.3) 3.2 AFUDC (1.5) (1.4) (1.3) Parent Company Loss Benefit (5.6) (1.6) (0.6) Tax Reform Excess ADIT Reversal (21.9) (29.9) (16.0) Other (2.7) (1.4) 0.9 Income Tax Expense (Benefit) $ 9.4 $ (4.7) $ 20.4 Effective Income Tax Rate 4.9 % (3.0) % 12.0 % 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, 2020 2019 (in millions) Deferred Tax Assets $ 3,259.7 $ 3,246.1 Deferred Tax Liabilities (11,500.6) (10,834.3) Net Deferred Tax Liabilities $ (8,240.9) $ (7,588.2) Property Related Temporary Differences $ (7,340.5) $ (6,602.9) Amounts Due to Customers for Future Income Taxes 1,075.8 1,173.5 Deferred State Income Taxes (1,317.6) (1,198.0) Securitized Assets (140.0) (178.7) Regulatory Assets (391.6) (371.1) Accrued Nuclear Decommissioning (626.4) (557.4) Net Operating Loss Carryforward 112.9 77.6 Tax Credit Carryforward 323.6 247.2 Operating Lease Liability 183.7 182.6 Investment in Partnership (362.0) (446.6) All Other, Net 241.2 85.6 Net Deferred Tax Liabilities $ (8,240.9) $ (7,588.2) AEP Texas December 31, 2020 2019 (in millions) Deferred Tax Assets $ 183.6 $ 220.0 Deferred Tax Liabilities (1,200.3) (1,185.4) Net Deferred Tax Liabilities $ (1,016.7) $ (965.4) Property Related Temporary Differences $ (1,039.6) $ (973.5) Amounts Due to Customers for Future Income Taxes 114.4 126.7 Deferred State Income Taxes (29.1) (27.5) Securitized Transition Assets (90.2) (124.3) Regulatory Assets (47.4) (51.2) Operating Lease Liability 18.0 17.2 All Other, Net 57.2 67.2 Net Deferred Tax Liabilities $ (1,016.7) $ (965.4) AEPTCo December 31, 2020 2019 (in millions) Deferred Tax Assets $ 166.5 $ 162.9 Deferred Tax Liabilities (1,073.4) (980.7) Net Deferred Tax Liabilities $ (906.9) $ (817.8) Property Related Temporary Differences $ (937.8) $ (847.1) Amounts Due to Customers for Future Income Taxes 118.9 119.9 Deferred State Income Taxes (98.3) (86.1) Net Operating Loss Carryforward 13.2 12.3 All Other, Net (2.9) (16.8) Net Deferred Tax Liabilities $ (906.9) $ (817.8) APCo December 31, 2020 2019 (in millions) Deferred Tax Assets $ 500.6 $ 486.2 Deferred Tax Liabilities (2,250.5) (2,167.0) Net Deferred Tax Liabilities $ (1,749.9) $ (1,680.8) Property Related Temporary Differences $ (1,412.0) $ (1,420.0) Amounts Due to Customers for Future Income Taxes 198.3 222.8 Deferred State Income Taxes (336.5) (337.2) Securitized Assets (44.7) (49.3) Regulatory Assets (114.8) (71.0) Operating Lease Liability 16.7 16.5 All Other, Net (56.9) (42.6) Net Deferred Tax Liabilities $ (1,749.9) $ (1,680.8) I&M December 31, 2020 2019 (in millions) Deferred Tax Assets $ 989.5 $ 970.5 Deferred Tax Liabilities (2,053.9) (1,950.2) Net Deferred Tax Liabilities $ (1,064.4) $ (979.7) Property Related Temporary Differences $ (409.2) $ (430.7) Amounts Due to Customers for Future Income Taxes 147.9 169.6 Deferred State Income Taxes (211.1) (194.4) Regulatory Assets (16.5) (26.9) Accrued Nuclear Decommissioning (626.4) (557.4) Operating Lease Liability 46.6 61.9 All Other, Net 4.3 (1.8) Net Deferred Tax Liabilities $ (1,064.4) $ (979.7) OPCo December 31, 2020 2019 (in millions) Deferred Tax Assets $ 210.8 $ 202.3 Deferred Tax Liabilities (1,165.9) (1,051.6) Net Deferred Tax Liabilities $ (955.1) $ (849.3) Property Related Temporary Differences $ (1,016.0) $ (890.8) Amounts Due to Customers for Future Income Taxes 121.1 130.2 Deferred State Income Taxes (40.7) (35.5) Regulatory Assets (53.7) (48.0) Operating Lease Liability 19.4 18.3 All Other, Net 14.8 (23.5) Net Deferred Tax Liabilities $ (955.1) $ (849.3) PSO December 31, 2020 2019 (in millions) Deferred Tax Assets $ 239.8 $ 257.4 Deferred Tax Liabilities (928.3) (885.7) Net Deferred Tax Liabilities $ (688.5) $ (628.3) Property Related Temporary Differences $ (661.8) $ (627.6) Amounts Due to Customers for Future Income Taxes 118.5 127.2 Deferred State Income Taxes (107.7) (100.4) Regulatory Assets (39.1) (44.6) Net Operating Loss Carryforward 12.9 10.2 All Other, Net (11.3) 6.9 Net Deferred Tax Liabilities $ (688.5) $ (628.3) SWEPCo December 31, 2020 2019 (in millions) Deferred Tax Assets $ 338.1 $ 359.6 Deferred Tax Liabilities (1,355.7) (1,300.5) Net Deferred Tax Liabilities $ (1,017.6) $ (940.9) Property Related Temporary Differences $ (985.1) $ (947.6) Amounts Due to Customers for Future Income Taxes 162.7 169.8 Deferred State Income Taxes (214.7) (200.3) Regulatory Assets (26.2) (30.2) Net Operating Loss Carryforward 33.4 38.2 All Other, Net 12.3 29.2 Net Deferred Tax Liabilities $ (1,017.6) $ (940.9) 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 loss of the parent company (Parent Company Loss Benefit) to the AEP System subsidiaries with taxable income reducing their current tax expense proportionately. The consolidated NOL of the AEP System is allocated to each company in the consolidated group with taxable losses. With the exception of the allocation of the consolidated AEP System NOL, 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 Income Tax Audit Status The statute of limitations for the IRS to examine AEP and subsidiaries originally filed federal return has expired for tax years 2016 and earlier. In the third quarter of 2019, AEP and subsidiaries elected to amend the 2014 and 2015 federal returns. In the first quarter of 2020, the IRS notified AEP that it was beginning an examination of these amended returns, including the NOL carryback to 2015 that originated in the 2017 return. As of December 31, 2020, the IRS has not challenged any items on these returns and the IRS is limited in their proposed adjustments to the amount AEP claimed on the amended returns. Net Income Tax Operating Loss Carryforward As of December 31, 2020, 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 $ 87.2 2021 - 2028 AEP Kentucky 163.7 2030 - 2037 AEP Louisiana 466.8 2025 - 2040 AEP Oklahoma 569.4 2034 - 2037 AEP Tennessee 31.1 2028 - 2035 AEP Virginia 29.4 2025 - 2037 AEP West Virginia 21.9 2029 - 2037 AEP Ohio Municipal 649.8 2021 - 2025 AEP Indiana 145.7 2039 AEP Colorado 95.7 NA AEP Pennsylvania 56.5 2030 - 2040 AEP New Jersey 60.2 2036 - 2040 AEP Illinois 15.6 2031 AEP Michigan 14.9 2029 AEPTCo Oklahoma 195.4 2034 - 2037 AEPTCo Ohio Municipal 18.4 2023 I&M West Virginia 2.5 2032 - 2037 PSO Oklahoma 354.5 2034 - 2037 SWEPCo Arkansas 86.4 2021 - 2024 SWEPCo Louisiana 454.3 2032 - 2037 As of December 31, 2020, AEP recorded a valuation allowance of $9 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 2016, 2017 and 2019 resulted in unused federal and state income tax credits. As of December 31, 2020, 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 2036 through 2040 and state tax credits will remain available indefinitely. Total Federal Total State Tax Credit Tax Credit Company Carryforward Carryforward (in millions) AEP $ 323.6 $ 38.4 AEP Texas 1.2 — AEPTCo 0.1 — APCo 1.6 — I&M 9.7 — OPCo 0.5 — PSO 0.5 38.4 SWEPCo 1.3 — 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, future reversals of existing temporary differences and tax planning strategies. Valuation allowance activity for the years ended December 31, 2020, 2019 and 2018 was immaterial. Uncertain Tax Positions The reconciliations of the beginning and ending amounts of unrecognized tax benefits for AEP are presented below. The amount and activity of unrecognized tax benefits for Registrants Subsidiaries was immaterial for periods presented: AEP 2020 2019 2018 (in millions) Balance as of January 1, $ 24.1 $ 14.6 $ 86.6 Increase – Tax Positions Taken During a Prior Period 0.6 8.8 0.1 Decrease – Tax Positions Taken During a Prior Period (14.5) (2.1) — Increase – Tax Positions Taken During the Current Year 3.0 2.8 — 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, $ 13.2 $ 24.1 $ 14.6 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 AEP as of December 31, 2020, 2019 and 2018 were $12 million, $20 million and $12 million, respectively. Federal Tax Legislation In March 2020, the CARES Act was signed into law. The CARES Act includes tax relief provisions such as: (a) an AMT Credit Refund, (b) a 5-year NOL carryback from years 2018-2020 and (c) delayed payment of employer payroll taxes. Pursuant to the CARES Act, AEP, APCo and OPCo requested and in July received refunds of AMT credit of $20 million, $7 million and $9 million, respectively. In the third quarter of 2020, AEP also requested a $95 million refund of taxes paid in 2014 under the 5-year NOL carryback provision of the CARES Act. AEP carried back a NOL generated on the 2019 Federal income tax return at a 21% federal corporate income tax rate to the 2014 Federal income tax return at a 35% corporate income tax rate. As a result of the change in the corporate income tax rates between the two periods, AEP realized a tax benefit of $48 million primarily at the Generation & Marketing segment. Management will continue to monitor potential legislation and any impacts to the AMT Credit and NOL refunds that were filed in 2020 pursuant to the CARES Act. In December 2020, the CAA of 2021 was signed into law. The CAA of 2021 includes: (a) COVID-19 tax relief and tax extender provisions including extensions of time to begin construction on and placed in-service assets generating PTCs and ITCs, (b) 100% deductibility of business meals in 2021 and 2022 and (c) an extension of the work opportunity tax credit. The ITC percentage has been increased for projects starting construction through 2023 and placed in-service by the end of 2025. The PTC has been extended for an additional year, to include projects started in 2021 and completed in 2025. These provisions provide time and flexibility on the construction start and in-service dates. In September and November 2020, the IRS issued final regulations that provide guidance regarding the additional first-year depreciation deduction under Section 168(k). The final regulations reflect changes as a result of Tax Reform, which affects 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. AEP’s competitive businesses will be eligible for 100% expensing. The IRS issued final regulations in 2020 that provide guidance 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 de minimis tests under which all interest is deductible if less than 10% is allocable to the competitive businesses. AEP will deduct materially all business interest expense under this de minimis provision. On December 30, 2020, the IRS issued regulations that provide guidance on the non-deductibility of certain executives compensation above $1 million under Internal Revenue Code Section 162(m). The regulations clarify the application of rules passed under Tax Reform that expanded the application of Section 162(m) to SEC registered companies that issue either public equity or debt. These rules also expanded the type of compensation and the number of executives subject to this deduction disallowance. AEP limits certain executives’ compensation to the $1 million limitation on its federal income tax return.

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases	13. LEASES The disclosures in this note apply to all Registrants unless indicated otherwise. Management adopted ASU 2016-02 effective January 1, 2019 by means of a cumulative-effect adjustment to the balance sheets. 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. AEP does not separate non-lease components from associated lease components. 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, 2020 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Operating Lease Cost $ 279.6 $ 17.4 $ 2.6 $ 19.1 $ 101.5 $ 17.1 $ 7.8 $ 9.4 Finance Lease Cost: Amortization of Right-of-Use Assets 61.9 6.3 — 7.4 6.5 4.7 3.5 10.9 Interest on Lease Liabilities 15.4 1.5 — 2.7 3.1 0.9 0.7 2.2 Total Lease Rental Costs (a) $ 356.9 $ 25.2 $ 2.6 $ 29.2 $ 111.1 $ 22.7 $ 12.0 $ 22.5 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 (a) Excludes variable and short-term lease costs, which were immaterial for the twelve months ended December 31, 2020 and December 31, 2019. Supplemental information related to leases are shown in the tables below: December 31, 2020 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo Weighted-Average Remaining Lease Term (years): Operating Leases 5.30 6.51 2.01 6.27 3.50 7.44 7.03 7.54 Finance Leases 5.43 6.07 0.00 5.75 5.79 5.90 6.16 4.95 Weighted-Average Discount Rate: Operating Leases 3.44 % 3.60 % 1.51 % 3.48 % 3.42 % 3.60 % 3.39 % 3.45 % Finance Leases 5.68 % 4.39 % — % 7.33 % 8.29 % 4.25 % 4.35 % 4.77 % 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, 2020 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 $ 280.3 $ 17.1 $ 2.6 $ 19.2 $ 102.2 $ 16.9 $ 7.7 $ 9.4 Operating Cash Flows Used for Finance Leases 15.4 1.5 — 2.7 3.1 0.9 0.7 2.2 Financing Cash Flows Used for Finance Leases 61.7 6.3 — 7.4 6.5 4.7 3.5 10.9 Non-cash Acquisitions Under Operating Leases $ 161.7 $ 15.8 $ 1.8 $ 16.2 $ 18.1 $ 18.1 $ 12.3 $ 18.4 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, 2020 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Property, Plant and Equipment Under Finance Leases: Generation $ 138.2 $ — $ — $ 42.8 $ 28.8 $ — $ 0.7 $ 37.7 Other Property, Plant and Equipment 322.8 49.7 — 20.3 40.2 31.4 23.0 52.4 Total Property, Plant and Equipment 461.0 49.7 — 63.1 69.0 31.4 23.7 90.1 Accumulated Amortization 176.8 16.6 — 21.4 27.3 9.8 8.7 36.5 Net Property, Plant and Equipment Under Finance Leases $ 284.2 $ 33.1 $ — $ 41.7 $ 41.7 $ 21.6 $ 15.0 $ 53.6 Obligations Under Finance Leases: Noncurrent Liability $ 231.0 $ 26.8 $ — $ 34.4 $ 35.3 $ 16.9 $ 11.9 $ 44.6 Liability Due Within One Year 58.1 6.3 — 7.3 6.4 4.7 3.1 10.7 Total Obligations Under Finance Leases $ 289.1 $ 33.1 $ — $ 41.7 $ 41.7 $ 21.6 $ 15.0 $ 55.3 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, 2020 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Operating Lease Assets $ 866.4 $ 84.1 $ 1.6 $ 78.8 $ 218.1 $ 92.0 $ 42.6 $ 48.5 Obligations Under Operating Leases: Noncurrent Liability $ 638.4 $ 71.0 $ 0.4 $ 64.4 $ 135.9 $ 79.5 $ 36.2 $ 44.1 Liability Due Within One Year 241.3 14.5 1.2 14.9 85.6 13.1 6.5 7.9 Total Obligations Under Operating Leases $ 879.7 $ 85.5 $ 1.6 $ 79.3 $ 221.5 $ 92.6 $ 42.7 $ 52.0 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, 2020: Finance Leases AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) 2021 $ 72.2 $ 7.6 $ — $ 9.9 $ 9.3 $ 5.5 $ 3.6 $ 13.1 2022 64.0 6.9 — 9.4 8.6 4.6 3.1 11.8 2023 56.2 6.2 — 8.7 7.9 3.9 2.7 10.9 2024 63.5 5.4 — 8.1 11.1 3.3 2.3 15.3 2025 32.7 4.0 — 7.0 5.5 2.2 1.6 5.7 Later Years 48.9 7.8 — 6.4 12.2 4.9 3.8 5.8 Total Future Minimum Lease Payments 337.5 37.9 — 49.5 54.6 24.4 17.1 62.6 Less: Imputed Interest 48.4 4.8 — 7.8 12.9 2.8 2.1 7.3 Estimated Present Value of Future Minimum Lease Payments $ 289.1 $ 33.1 $ — $ 41.7 $ 41.7 $ 21.6 $ 15.0 $ 55.3 Operating Leases AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) 2021 $ 270.8 $ 17.5 $ 1.2 $ 17.7 $ 92.5 $ 16.6 $ 7.9 $ 10.1 2022 263.3 16.4 0.2 17.0 92.5 16.0 7.6 9.6 2023 94.2 14.8 0.1 14.2 11.4 14.9 7.3 8.4 2024 81.6 13.3 0.1 11.3 10.0 13.2 6.5 6.9 2025 68.0 10.9 — 8.5 8.9 11.5 5.4 5.8 Later Years 193.0 23.9 — 20.0 21.8 34.0 13.3 17.4 Total Future Minimum Lease Payments 970.9 96.8 1.6 88.7 237.1 106.2 48.0 58.2 Less: Imputed Interest 91.2 11.3 — 9.4 15.6 13.6 5.3 6.2 Estimated Present Value of Future Minimum Lease Payments $ 879.7 $ 85.5 $ 1.6 $ 79.3 $ 221.5 $ 92.6 $ 42.7 $ 52.0 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 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, 2020, 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 (in millions) AEP $ 50.3 AEP Texas 11.7 APCo 6.6 I&M 4.4 OPCo 8.1 PSO 4.8 SWEPCo 5.4 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. In November 2020, management announced that AEP will not renew the lease when it expires in 2022. 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, 2020 were as follows: Future Minimum Lease Payments AEP (a) I&M (in millions) 2021 $ 147.8 $ 73.9 2022 147.6 73.8 Total Future Minimum Lease Payments $ 295.4 $ 147.7 (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, 2020, the maximum potential amount of future payments required under the guaranteed leases was $48 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, 2020, AEP’s boat and barge lease guarantee liability was $3 million, of which $1 million was recorded in Other Current Liabilities and $2 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. In March 2020, the bankruptcy court approved the party’s recapitalization plan. In April 2020, the nonaffiliated party emerged from bankruptcy. 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, 2020 and December 31, 2019, respectively.

Financing Activities

Financing Activities	12 Months Ended
	Dec. 31, 2020
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, 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 Issued 2,434,723 — Balance, December 31, 2020 516,808,354 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. At-the-Market (ATM) Program In November 2020, AEP filed a prospectus supplement and executed an Equity Distribution Agreement (EDA), pursuant to which AEP may sell, from time to time, up to an aggregate of $1 billion of its common stock through an ATM offering program, including an equity forward sales component. The compensation paid to the selling agents by AEP may be up to 2% of the gross offering proceeds of the shares. There were no issuances under the ATM program for the year ended December 31, 2020. Reverse Stock Split (Applies to SWEPCo) In August 2020, SWEPCo executed a reverse stock split with each 2,048 shares of common stock issued and outstanding being combined into one share of common stock. The common stock of SWEPCo is wholly-owned by Parent. 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, 2020 2020 2019 2020 2019 AEP (in millions) Senior Unsecured Notes 2020-2050 3.97% 0.70%-8.13% 2.15%-8.13% $ 25,116.1 $ 21,180.7 Pollution Control Bonds (a) 2020-2036 (b) 2.39% 0.18%-4.63% 1.35%-5.38% 1,936.7 1,998.8 Notes Payable – Nonaffiliated (c) 2020-2032 2.34% 0.84%-6.37% 2.42%-6.37% 239.1 234.3 Securitization Bonds 2020-2029 (d) 2.78% 2.01%-3.77% 1.98%-5.31% 716.4 1,025.1 Spent Nuclear Fuel Obligation (e) 281.2 279.8 Junior Subordinated Notes (f) 2022-2023 2.32% 1.30%-3.40% 3.40% 1,624.1 787.8 Other Long-term Debt 2020-2059 1.59% 0.81%-13.72% 1.15%-13.718% 1,158.9 1,219.0 Total Long-term Debt Outstanding $ 31,072.5 $ 26,725.5 AEP Texas Senior Unsecured Notes 2022-2050 3.70% 2.10%-6.76% 2.40%-6.76% $ 3,687.6 $ 3,090.9 Pollution Control Bonds 2020-2030 (b) 3.42% 0.90%-4.55% 1.75%-4.55% 439.7 490.3 Securitization Bonds 2020-2029 (d) 2.55% 2.06%-2.84% 1.98%-5.31% 492.6 776.8 Other Long-term Debt 2022-2059 1.41% 1.40%-4.50% 3.05%-4.50% 200.5 200.4 Total Long-term Debt Outstanding $ 4,820.4 $ 4,558.4 AEPTCo Senior Unsecured Notes 2021-2050 3.83% 3.10%-5.52% 3.10%-5.52% $ 3,948.5 $ 3,427.3 Total Long-term Debt Outstanding $ 3,948.5 $ 3,427.3 APCo Senior Unsecured Notes 2021-2050 4.94% 3.30%-7.00% 3.30%-7.00% $ 3,937.2 $ 3,442.7 Pollution Control Bonds (a) 2020-2036 (b) 1.77% 0.19%-4.63% 1.67%-5.38% 546.3 546.1 Securitization Bonds 2023-2028 (d) 3.29% 2.01%-3.77% 2.008%-3.772% 223.8 248.3 Other Long-term Debt 2022-2026 1.51% 1.32%-13.72% 2.97%-13.718% 126.8 126.7 Total Long-term Debt Outstanding $ 4,834.1 $ 4,363.8 I&M Senior Unsecured Notes 2023-2048 4.38% 3.20%-6.05% 3.20%-6.05% $ 2,152.2 $ 2,150.7 Pollution Control Bonds (a) 2021-2025 (b) 2.21% 0.18%-3.05% 1.79%-3.05% 240.5 240.0 Notes Payable – Nonaffiliated (c) 2020-2025 1.06% 0.84%-1.29% 2.42%-2.80% 146.7 168.7 Spent Nuclear Fuel Obligation (e) 281.2 279.8 Other Long-term Debt 2021-2025 1.49% 1.28%-6.00% 2.93%-6.00% 209.3 211.0 Total Long-term Debt Outstanding $ 3,029.9 $ 3,050.2 OPCo Senior Unsecured Notes 2021-2049 4.82% 2.60%-6.60% 4.00%-6.60% $ 2,429.4 $ 2,081.0 Other Long-term Debt 2028 1.15% 1.15% 1.15% 0.8 1.0 Total Long-term Debt Outstanding $ 2,430.2 $ 2,082.0 PSO Senior Unsecured Notes 2021-2049 4.55% 3.05%-6.63% 3.05%-6.625% $ 1,246.3 $ 1,245.6 Pollution Control Bonds 2020 4.45% — 12.7 Other Long-term Debt 2022-2027 1.47% 1.42%-3.00% 3.00%-3.20% 127.5 127.9 Total Long-term Debt Outstanding $ 1,373.8 $ 1,386.2 SWEPCo Senior Unsecured Notes 2022-2048 4.04% 2.75%-6.20% 2.75%-6.20% $ 2,430.8 $ 2,428.9 Notes Payable – Nonaffiliated (c) 2024-2032 5.30% 4.58%-6.37% 4.58%-6.37% 62.4 65.6 Other Long-term Debt 2021-2035 2.99% 2.25%-4.68% 3.08%-4.68% 143.2 161.1 Total Long-term Debt Outstanding $ 2,636.4 $ 2,655.6 (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. Consequently, these bonds have been classified for maturity purposes as Long-term Debt Due Within One Year - Nonaffiliated on the balance sheets. (b) Certain Pollution Control Bonds are subject to redemption earlier than the maturity date. (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, 2020, outstanding long-term debt was payable as follows: AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) 2021 $ 2,086.1 $ 88.7 $ 50.0 $ 518.3 $ 369.6 $ 500.1 $ 0.5 $ 106.2 2022 3,538.4 (a) 716.0 104.0 355.4 45.1 0.1 375.5 281.2 2023 2,659.3 (b) 278.5 60.0 26.6 273.9 0.1 0.5 6.2 2024 723.4 96.0 95.0 113.5 8.1 0.1 0.6 31.2 2025 1,726.3 324.5 90.0 443.9 151.5 0.1 125.6 6.2 After 2025 20,599.2 3,357.0 3,591.0 3,418.3 2,206.2 1,950.3 875.8 2,225.5 Principal Amount 31,332.7 4,860.7 3,990.0 4,876.0 3,054.4 2,450.8 1,378.5 2,656.5 Unamortized Discount, Net and Debt Issuance Costs (260.2) (40.3) (41.5) (41.9) (24.5) (20.6) (4.7) (20.1) Total Long-term Debt Outstanding $ 31,072.5 $ 4,820.4 $ 3,948.5 $ 4,834.1 $ 3,029.9 $ 2,430.2 $ 1,373.8 $ 2,636.4 (a) Amount includes $805 million of Junior Subordinated Notes. See “Equity Units” section below for additional information. (b) Amount includes $850 million of Junior Subordinated Notes. See “Equity Units” section below for additional information. Long-term Debt Subsequent Events In January and February 2021, I&M retired $8 million and $7 million, respectively, of Notes Payable related to DCC Fuel. In January 2021, OPCo issued $450 million of Senior Unsecured Notes. In January 2021, PSO issued $400 million of variable rate Other Long-term Debt due in 2022, which it used to retire $250 million of Senior Unsecured Notes in February 2021. In January and February 2021, Transource Energy issued $5 million and $9 million, respectively, of variable rate Other Long-term Debt due in 2023. In February 2021, AEP Texas retired $11 million of Securitization Bonds. In February 2021, APCo retired $12 million of Securitization Bonds. Equity Units (Applies to AEP) 2020 Equity Units In August 2020, AEP issued 17 million Equity Units initially in the form of corporate units, at a stated amount of $50 per unit, for a total stated amount of $850 million. Net proceeds from the issuance were approximately $833 million. The proceeds were used to support AEP’s overall capital expenditure plans. Each corporate unit represents a 1/20 undivided beneficial ownership interest in $1,000 principal amount of AEP’s 1.30% Junior Subordinated Notes (notes) due in 2025 and a forward equity purchase contract which settles after three years in 2023. The notes are expected to be remarketed in 2023, 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 1.30% and a quarterly forward equity purchase contract payment of 4.825%. 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 $99.95: 0.5003 shares per contract. • If the AEP common stock market price is less than $99.95 but greater than $83.29: 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 $83.29: 0.6003 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 $850 million of notes were recorded within Long-term Debt on the balance sheets. The present value of the purchase contract payments of $121 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 2023. 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 10,205,100 shares (subject to an anti-dilution adjustment). 2019 Equity Units 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, 2020. 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, 2020, 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 $14 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, 2020, the amount of any such restrictions were as follows: AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Restricted Retained Earnings $ 2,369.5 (a) $ 694.0 $ — $ 175.1 $ 519.7 $ — $ 182.3 $ 571.9 (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, 2020, AEP had $7.1 billion of available retained earnings to pay dividends to common shareholders. AEP paid $1.4 billion, $1.3 billion and $1.3 billion of dividends to common shareholders for the years ended December 31, 2020, 2019 and 2018, 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, 2020, AEP had a $4 billion revolving credit facility to support its commercial paper program. The commercial paper program for the year ended 2020, had a weighted-average interest rate of 1.28% and a maximum amount outstanding of $3 billion. AEP’s outstanding short-term debt was as follows: December 31, 2020 2019 Company Type of Debt Outstanding Interest Outstanding Interest (in millions) (in millions) AEP Securitized Debt for Receivables (b) $ 592.0 0.85 % $ 710.0 2.42 % AEP Commercial Paper 1,852.3 0.29 % 2,110.0 2.10 % SWEPCo Notes Payable 35.0 2.55 % 18.3 3.29 % Total Short-term Debt $ 2,479.3 $ 2,838.3 (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, 2020 and 2019 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, 2020: 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, 2020 Limit (in millions) AEP Texas $ 320.4 $ 313.4 $ 132.0 $ 139.0 $ (67.1) $ 500.0 AEPTCo 358.4 259.7 116.3 55.0 (155.4) 820.0 (a) APCo 434.3 189.0 242.8 76.3 2.8 500.0 I&M 218.6 13.4 114.5 13.3 (89.7) 500.0 OPCo 353.9 32.8 182.4 25.2 (259.2) 500.0 PSO 155.4 57.1 72.3 28.4 (155.4) 300.0 SWEPCo 178.9 — 113.0 — (124.6) 350.0 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 (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, 2020 and 2019 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, 2020: 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, 2020 (in millions) AEP Texas $ 7.5 $ 7.1 $ 7.1 SWEPCo 2.1 2.1 2.1 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 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, 2020 and 2019 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, 2020: 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, 2020 December 31, 2020 Borrowing Limit (in millions) $ 1.4 $ 215.3 $ 1.3 $ 132.6 $ 1.2 $ 109.0 $ 50.0 (a) 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) (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, 2020 2019 2018 Maximum Interest Rate 2.70 % 3.43 % 2.97 % Minimum Interest Rate 0.27 % 1.77 % 1.81 % 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 Average Interest Rate for Funds Loaned Company 2020 2019 2018 2020 2019 2018 AEP Texas 1.51 % 2.63 % 2.26 % 0.81 % 2.03 % 2.29 % AEPTCo 1.29 % 2.64 % 2.27 % 1.99 % 2.41 % 2.10 % APCo 2.12 % 2.45 % 2.26 % 0.85 % 2.66 % 2.21 % I&M 1.07 % 2.34 % 2.16 % 1.18 % 2.60 % 2.08 % OPCo 0.99 % 2.67 % 2.18 % 2.06 % 2.68 % 2.47 % PSO 0.92 % 2.85 % 2.27 % 1.95 % 2.27 % 1.98 % SWEPCo 1.27 % 2.72 % 2.31 % — % 2.22 % 2.00 % Maximum, minimum and average interest rates for funds 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 2020 AEP Texas 2.70 % 0.27 % 1.18 % 2020 SWEPCo 2.70 % 0.27 % 1.18 % 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 % 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 2020 2.70 % 0.27 % 2.70 % 0.27 % 1.20 % 1.13 % 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 % 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, 2020, 2019 and 2018. 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 September 2022. 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. In May 2020, AEP Credit amended its receivables securitization agreement to increase the eligibility criteria related to aged receivable requirements for the participating affiliated utility subsidiaries in response to the COVID-19 pandemic. As of December 31, 2020, the affiliated utility subsidiaries are in compliance with all requirements under the agreement. To the extent that an affiliated utility subsidiary is deemed ineligible under the agreement, the affiliated utility subsidiary would no longer participate in the receivables securitization agreement and the Registrants would need to rely on additional sources of funding for operation and working capital, which may adversely impact liquidity. The receivables that are ineligible under the receivables securitization agreement are financed with short-term debt at AEP Credit. Accounts receivable information for AEP Credit was as follows: Years Ended December 31, 2020 2019 2018 (dollars in millions) Effective Interest Rates on Securitization of Accounts Receivable 0.85 % 2.42 % 2.16 % Net Uncollectible Accounts Receivable Written Off $ 15.3 $ 26.6 $ 27.6 December 31, 2020 2019 (in millions) Accounts Receivable Retained Interest and Pledged as Collateral Less Uncollectible Accounts $ 958.4 $ 841.8 Short-term – Securitized Debt of Receivables 592.0 710.0 Delinquent Securitized Accounts Receivable 62.3 39.6 Bad Debt Reserves Related to Securitization 60.0 32.1 Unbilled Receivables Related to Securitization 296.8 266.8 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 AEP Texas and AEPTCo) 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 2020 2019 (in millions) APCo $ 136.0 $ 120.9 I&M 170.5 141.8 OPCo 398.8 330.3 PSO 85.0 101.1 SWEPCo 158.6 125.2 The fees paid to AEP Credit for customer accounts receivable sold were: Years Ended December 31, Company 2020 2019 2018 (in millions) APCo $ 5.2 $ 7.4 $ 7.0 I&M 7.9 11.1 9.2 OPCo 24.1 27.1 26.3 PSO 4.8 7.8 7.9 SWEPCo 6.7 10.2 8.9 The proceeds on the sale of receivables to AEP Credit were: Years Ended December 31, Company 2020 2019 2018 (in millions) APCo $ 1,272.9 $ 1,310.3 $ 1,421.0 I&M 1,891.8 1,824.2 1,843.0 OPCo 2,366.2 2,293.6 2,674.5 PSO 1,221.0 1,442.5 1,484.6 SWEPCo 1,593.8 1,618.5 1,736.1

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2020
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 (Prior Plan), was replaced prospectively for new grants by the American Electric Power System 2015 Long-Term Incentive Plan (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, 2020, 6,712,148 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. Each share issued for any other award that settles in AEP stock reduces 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 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. Performance shares are recorded as mezzanine equity on the balance sheets until the vesting date and compensation cost is calculated at fair value based on metrics for each grant. Performance shares granted in 2020 had three performance metrics: (a) three-year cumulative operating earnings per-share with a 50% weight, (b) total shareholder return with a 40% weight and (c) non-emitting generation capacity as a percentage of total owned and purchased capacity with a 10% weight. Performance shares granted prior to 2020 had two equally-weighted performance metrics: (a) three-year cumulative operating earnings per-share and (b) total shareholder return. The three-year cumulative operating earnings per-share metric and non-emitting generating capacity metric are adjusted quarterly for changes in performance relative to a target approved by the HR Committee. The total shareholder return metric is measured relative to a peer group of similar companies and is based on a third-party Monte Carlo valuation. The value related to this metric does not change over the three-year vesting period. 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 2020 2019 2018 Awarded Shares (in thousands) 424.8 535.0 581.4 Weighted-Average Share Fair Value at Grant Date $ 116.56 $ 83.21 $ 67.21 Vesting Period (in years) 3 3 3 Performance Shares and AEP Career Shares Years Ended December 31, 2020 2019 2018 Awarded Shares (in thousands) (a) 73.4 66.4 80.2 Weighted-Average Fair Value at Grant Date $ 84.87 $ 88.73 $ 70.58 Vesting Period (in years) (b) (b) (b) (a) All awarded dividends in both 2020 and 2019 were equity awards and awarded dividends in 2018 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 certified performance scores and shares earned for the three-year periods were as follows: Years Ended December 31, Performance Shares 2020 2019 2018 Certified Performance Score 128.2 % 132.7 % 136.7 % Performance Shares Earned 757,858 792,897 820,780 Performance Shares Mandatorily Deferred as AEP Career Shares 13,614 10,063 11,248 Performance Shares Voluntarily Deferred into the Incentive Compensation Deferral Program 26,936 49,392 56,826 Performance Shares to be Settled (a) 717,308 733,442 752,706 (a) Performance shares settled for the three-year periods ended December 31, 2020 and 2019 settled in AEP common stock. Performance units settled for the three-year period ended December 31, 2018 settled in cash. In all cases, the settlement of common stock or cash occurs in the quarter following the end of the year shown. The settlements were as follows: Years Ended December 31, Performance Shares and AEP Career Shares 2020 2019 2018 (in millions) Cash Settlements for Performance Units $ — $ 58.3 $ 66.9 AEP Common Stock Settlements for Performance Shares 75.4 — — AEP Common Stock Settlements for Career Share Distributions 1.9 6.6 5.1 A summary of the status of AEP’s nonvested Performance Shares as of December 31, 2020 and changes during the year ended December 31, 2020 were as follows: Nonvested Performance Shares Shares Weighted (in thousands) Nonvested as of January 1, 2020 1,113.4 $ 73.64 Awarded 424.8 116.56 Dividends 53.8 84.91 Vested (a) (597.0) 66.45 Forfeited (56.4) 87.58 Nonvested as of December 31, 2020 938.6 98.05 (a) The vested Performance Shares will be converted to 717 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 the fair value of the total shareholder return metric 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, Assumptions 2020 2019 2018 Valuation Period (in years) (a) 2.87 2.87 2.87 Expected Volatility Minimum 13.67 % 14.83 % 14.77 % Expected Volatility Maximum 28.15 % 25.57 % 26.72 % Expected Volatility Average 16.39 % 17.39 % 17.90 % Dividend Rate (b) — % — % — % Risk Free Rate 1.40 % 2.49 % 2.34 % (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 was 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 2020 2019 2018 Awarded Units (in thousands) 268.7 304.8 260.0 Weighted-Average Grant Date Fair Value $ 94.38 $ 81.57 $ 67.96 The total fair value and total intrinsic value of restricted stock units vested were as follows: Years Ended December 31, Restricted Stock Units 2020 2019 2018 (in millions) Fair Value of Restricted Stock Units Vested $ 22.9 $ 16.3 $ 16.6 Intrinsic Value of Restricted Stock Units Vested (a) 25.2 21.6 19.2 (a) Intrinsic value is calculated as market price at the vesting date. A summary of the status of AEP’s nonvested RSUs as of December 31, 2020 and changes during the year ended December 31, 2020 were as follows: Nonvested Restricted Stock Units Shares/Units Weighted (in thousands) Nonvested as of January 1, 2020 516.9 $ 75.55 Awarded 268.7 94.38 Vested (307.6) 74.58 Forfeited (30.0) 84.27 Nonvested as of December 31, 2020 448.0 86.56 The total aggregate intrinsic value of nonvested RSUs as of December 31, 2020 was $37 million and the weighted-average remaining contractual life was 1.6 years. Retirement Incentive and Severance Awards In 2020 64,186 shares with a weighted-average grant date fair value of $83.74 were granted in connection with the voluntary retirement incentive program and other executive severance. The shares were fully vested on the grant date with a fair value of $5 million. See “Voluntary Retirement Incentive Program” section of Note 1 for additional information. 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 the 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. These balances are also paid in cash upon termination of board service or up to 10 years later if the participant so elects. 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, 2020, 2019 and 2018, 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 2020 2019 2018 Awarded Units (in thousands) 12.1 10.0 11.4 Weighted-Average Grant Date Fair Value $ 83.80 $ 89.13 $ 70.41 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 2020 2019 2018 (in millions) Compensation Cost for Share-based Payment Arrangements (a) $ 53.8 $ 57.9 $ 53.2 Actual Tax Benefit 7.2 8.4 7.7 Total Compensation Cost Capitalized 20.4 20.0 19.7 (a) Compensation cost for share-based payment arrangements is included in Other Operation and Maintenance expenses on the statements of income. As of December 31, 2020, there was $78 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 is 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 1.39 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 tax withholding obligations.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2020
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, 2020 Direct Sales to East Affiliates $ — $ — $ 112.5 $ — $ — $ — $ — Auction Sales to OPCo (a) — — 5.3 3.1 — — — Direct Sales to AEPEP 87.5 — — — — — — Transmission Revenues — 885.0 49.1 2.9 16.6 — 37.4 Other Revenues 3.3 11.3 7.8 4.5 24.9 5.2 1.6 Total Affiliated Revenues $ 90.8 $ 896.3 $ 174.7 $ 10.5 $ 41.5 $ 5.2 $ 39.0 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 $ — $ — $ — $ — 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 $ — $ — $ — 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 (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, 2020, 2019 and 2018. Related Party Purchases I&M OPCo (in millions) Year Ended December 31, 2020 Auction Purchases from AEPEP (a) $ — $ 51.0 Auction Purchases from AEP Energy (a) — 58.7 Auction Purchases from AEPSC (a) — 10.0 Direct Purchases from AEGCo 172.8 — Total Affiliated Purchases $ 172.8 $ 119.7 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 (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) The AEP East Companies are parties to the 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 2020 2019 2018 (in millions) APCo $ 243.2 $ 222.3 $ 128.3 I&M 145.9 143.5 91.4 OPCo 417.4 373.4 210.1 The charges shown above are recorded in Other Operation expenses on the statements of income. PSO, SWEPCo and AEPSC are parties to the 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 2020 2019 2018 (in millions) PSO $ 69.7 $ 46.9 $ 65.9 SWEPCo 31.3 20.1 10.5 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 $28 million, $27 million and $27 million for transmission services in 2020, 2019 and 2018, 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 agreed to sell AEPEP 100% of AEP Texas’ capacity and associated energy from its undivided interest (54.69%) in the Oklaunion Power Station. The PPA was approved by the FERC. 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 paid AEP Texas the full Property, Plant and Equipment balance through depreciation payments until termination of the PPA due to the plant closing in September 2020. See “Dispositions” section of Note 7 for additional information. AEP Texas recorded revenue of $88 million, $157 million and $104 million from AEPEP for the years ended December 31, 2020, 2019 and 2018, 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 2020 2019 2018 (in millions) APCo $ 0.9 $ 0.2 $ — I&M 3.0 1.5 2.2 KPCo 0.4 0.3 0.2 OPCo 4.5 2.2 2.9 PSO 0.4 0.3 0.3 WPCo 0.2 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. 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. In November 2020, management announced that AEP will not renew the Rockport Plant, Unit 2 lease when it expires in December 2022. The I&M Power Agreement will continue in effect until the debt obligations of AEGCo secured by the Rockport Plant have been satisfied and discharged (currently expected to be December 2028). 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. In November 2020, management announced that AEP will not renew the Rockport Plant, Unit 2 lease when it expires in December 2022. 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 $12 million, $13 million and $12 million in 2020, 2019 and 2018, 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 2020 2019 2018 (in millions) I&M $ 0.9 $ 1.3 $ 1.5 PSO 0.7 0.8 0.7 SWEPCo 3.0 4.0 3.4 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 2020 2019 2018 (in millions) AEGCo $ 10.6 $ 14.9 $ 19.9 APCo 43.7 38.9 35.1 KPCo 3.2 4.8 4.2 WPCo 3.3 4.8 4.2 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 2020 2019 2018 (in millions) AGR $ 2.9 $ 0.8 $ 1.6 I&M 3.2 2.3 2.4 KPCo 0.9 1.4 1.7 PSO 0.9 1.1 0.5 SWEPCo 0.5 1.1 0.7 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 2020 2019 2018 (in millions) AEP Texas $ 0.9 $ 0.9 $ 0.3 AEPTCo 0.2 — — APCo 5.7 5.5 5.4 I&M 1.5 7.5 8.2 OPCo 7.0 7.0 10.7 PSO 1.1 0.8 1.0 SWEPCo 0.8 0.2 0.8 Purchases Years Ended December 31, Company 2020 2019 2018 (in millions) AEP Texas $ 1.5 $ 0.3 $ 0.1 AEPTCo 6.0 10.2 18.5 APCo 1.3 6.0 0.6 I&M 3.4 0.9 2.0 OPCo 1.2 3.0 2.8 PSO 0.4 0.5 1.3 SWEPCo 2.8 0.7 0.8 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. One of the joint venture wind farms has PPAs with I&M and OPCo for a portion of its energy production. The I&M portion totaled $11 million and $9 million and the OPCo portion totaled $23 million and $17 million, respectively, for the years ended December 31, 2020 and 2019. Another joint venture wind farm has a PPA with SWEPCo for a portion of its energy production which totaled $14 million and $10 million, respectively, of purchased electricity for the years ended December 31, 2020 and 2019. 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. In 2020, there were no charitable contributions made to the AEP Foundation. The charitable contributions to the AEP Foundation recorded in 2019 were as follows: Year Ended Company December 31, 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 OKTCo Radial Assets Transfer (Applies to AEP, AEPTCo and PSO) In August 2020, AEPSC filed a request with FERC, on behalf of PSO and OKTCo, to transfer OKTCo's interests in its radial assets to PSO. See “FERC Rate Matters” section of Note 4 for additional information.

Variable Interest Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2020
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, OPCo 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, 2020, 2019 and 2018 were $131 million, $110 million and $152 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 completion of reclamation. The mine end-of-life has been adjusted to March 2023, in order to align with the announced closure of the Pirkey Power Plant. Reclamation is expected to be complete by 2037 at an estimated cost of $104 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, 2020, SWEPCo has recorded $89 million of mine reclamation costs in Asset Retirement Obligations and has collected $81 million through a rider for reclamation costs. The remaining $8 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, 2020, 2019 and 2018 were $94 million, $95 million and $113 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. As of December 31, 2020 and 2019, $66 million and $267 million of the securitized bonds were included in Long-term Debt Due Within One Year - Nonaffiliated, respectively, and $209 million and $274 million were included in Long-term Debt - Nonaffiliated, respectively, on the balance sheets. Transition Funding has securitized transition assets of $242 million and $389 million as of December 31, 2020 and 2019, 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. 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. As of December 2020 and 2019, $23 million and $14 million of the securitized bonds were included in Long-term Debt Due Within One Year - Nonaffiliated, respectively, and $195 million and $221 million were included in Long-term Debt - Nonaffiliated, respectively, on the balance sheets. Restoration Funding has securitized assets of $205 million and $232 million as of December 31, 2020 and 2019, respectively, 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. 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. As of December 31, 2020 and 2019, $25 million and $25 million of the securitized bonds were included in Long-term Debt Due Within One Year - Nonaffiliated, respectively, and $199 million and $223 million were included in Long-term Debt - Nonaffiliated, respectively, on the balance sheets. Appalachian Consumer Rate Relief Funding has securitized assets of $210 million and $235 million as of December 31, 2020 and 2019, 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 25% 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, 2020, 2019 and 2018 was $31 million, $34 million and $34 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, Maryland and Oklahoma. 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%. 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. From January 2018 through July 2020, AEP owned 79.9% of the LLCs. As a result, management concluded that the LLCs were VIEs and that AEP was 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 sold power at market rates into ERCOT. AEP and the nonaffiliate shared 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. In August 2020, AEP exercised its call right which required the nonaffiliate to sell its noncontrolling interest in the LLCs to AEP. The nonaffiliates’ interest in the LLCs was presented as Redeemable Noncontrolling Interest on the balance sheets. The exercise price for the call right was determined using a discounted cash flow model with agreed input assumptions as well as updates to certain assumptions reasonably expected based on the actual results of the LLCs. As a result, the LLCs are wholly-owned by AEP and management has concluded that the LLCs are no longer VIEs. As of December 31, 2020 and 2019, AEP recorded $0 and $66 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, 2020 and 2019, AEP recorded $119 million and $128 million, respectively, 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 years ended December 31, 2020 and 2019, the HLBV method resulted in a loss of $6 million and $6 million, respectively, 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). In November 2020, AEP acquired an additional 10% interest in Santa Rita East resulting in AEP having a total interest of 85%. 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 $23 million and $10 million of PTC attributable to Santa Rita East for the years ended December 31, 2020 and 2019, respectively, 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, 2020 and 2019, AEP recorded $61 million and $118 million, respectively, 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, 2020 Registrant Subsidiaries SWEPCo I&M AEP Texas Transition Funding AEP Texas Restoration Funding APCo (in millions) ASSETS Current Assets $ 88.0 $ 76.1 $ 61.2 $ 23.3 $ 16.8 Net Property, Plant and Equipment 97.3 138.9 — — — Other Noncurrent Assets 99.3 70.9 273.9 (a) 214.9 (b) 212.7 (c) Total Assets $ 284.6 $ 285.9 $ 335.1 $ 238.2 $ 229.5 LIABILITIES AND EQUITY Current Liabilities $ 57.7 $ 76.0 $ 69.8 $ 33.9 $ 28.7 Noncurrent Liabilities 225.3 209.9 246.5 203.1 198.9 Equity 1.6 — 18.8 1.2 1.9 Total Liabilities and Equity $ 284.6 $ 285.9 $ 335.1 $ 238.2 $ 229.5 (a) Includes an intercompany item eliminated in consolidation of $32 million. (b) Includes an intercompany item eliminated in consolidation of $9 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, 2020 Other Consolidated VIEs AEP Credit Protected Transource Energy Apple Blossom and Black Oak Santa Rita East (in millions) ASSETS Current Assets $ 960.4 $ 198.1 $ 22.2 $ 9.6 $ 6.0 Net Property, Plant and Equipment — — 458.7 223.1 453.1 Other Noncurrent Assets 12.9 — 3.7 12.1 — Total Assets $ 973.3 $ 198.1 $ 484.6 $ 244.8 $ 459.1 LIABILITIES AND EQUITY Current Liabilities $ 827.2 $ 43.1 $ 32.6 $ 5.3 $ 3.5 Noncurrent Liabilities 0.8 62.5 185.0 4.9 6.7 Equity 145.3 92.5 267.0 234.6 448.9 Total Liabilities and Equity $ 973.3 $ 198.1 $ 484.6 $ 244.8 $ 459.1 American Electric Power Company, Inc. and Subsidiary Companies Variable Interest Entities December 31, 2019 Registrant Subsidiaries SWEPCo I&M AEP Texas Transition Funding AEP Texas Restoration Funding 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 Transource Energy Desert Sky 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 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, 2020, 2019 and 2018 were $142 million, $55 million and $58 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, 2020 2019 As Reported on Maximum As Reported on Maximum (in millions) Capital Contribution from SWEPCo $ 7.6 $ 7.6 $ 7.6 $ 7.6 Retained Earnings 20.4 20.4 17.5 17.5 SWEPCo’s Share of Obligations — 98.5 — 130.0 Total Investment in DHLC $ 28.0 $ 126.5 $ 25.1 $ 155.1 OVEC AEP and several nonaffiliated utility companies jointly own OVEC. As of December 31, 2020, 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, 2020 and 2019, OVEC’s outstanding indebtedness was approximately $1.3 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, 2020 2019 As Reported on Maximum 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) — 555.0 — 588.9 Total Investment in OVEC $ 4.4 $ 559.4 $ 4.4 $ 593.3 (a) Based on the Registrants’ power participation ratios APCo, I&M and OPCo’s share of OVEC debt was $200 million, $100 million and $255 million as of December 31, 2020 and $213 million, $106 million and $270 million as of December 31, 2019, 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 2020 2019 2018 (in millions) APCo $ 94.4 $ 104.5 $ 100.4 I&M 47.2 52.3 50.2 OPCo 120.8 132.7 127.5 AEPSC AEPSC provides certain managerial and professional services to AEP’s subsidiaries. Parent is the sole equity owner of AEPSC. AEP management controls the activities of AEPSC. The costs of the services are based on a direct-charge or on a prorated basis and billed to the AEP subsidiary companies at AEPSC’s cost. AEP subsidiaries have not provided financial or other support outside of the reimbursement of costs for services rendered. AEPSC finances its operations through cost reimbursement from other AEP subsidiaries. There are no other terms or arrangements between AEPSC and any of the AEP subsidiaries that could require additional financial support from an AEP subsidiary or expose them to losses outside of the normal course of business. AEPSC and its billings are subject to regulation by the FERC. AEP subsidiaries are exposed to losses to the extent they cannot recover the costs of AEPSC through their normal business operations. AEP subsidiaries are considered to have a significant interest in AEPSC due to their activity in AEPSC’s cost reimbursement structure. However, AEP subsidiaries do not have control over AEPSC. AEPSC is consolidated by AEP. In the event AEPSC would require financing or other support outside the cost reimbursement billings, this financing would be provided by AEP. Total AEPSC billings to the Registrant Subsidiaries were as follows: Years Ended December 31, Company 2020 2019 2018 (in millions) AEP Texas $ 199.4 $ 206.6 $ 184.3 AEPTCo 270.3 242.3 220.4 APCo 294.9 308.3 295.6 I&M 210.2 184.8 173.5 OPCo 232.8 230.4 214.9 PSO 113.2 125.7 121.5 SWEPCo 161.8 169.5 164.4 The carrying amount and classification of variable interest in AEPSC’s accounts payable were as follows: December 31, 2020 2019 Company As Reported on Maximum As Reported on Maximum (in millions) AEP Texas $ 30.5 $ 30.5 $ 32.4 $ 32.4 AEPTCo 45.9 45.9 33.4 33.4 APCo 42.8 42.8 44.1 44.1 I&M 27.1 27.1 28.6 28.6 OPCo 33.9 33.9 33.2 33.2 PSO 15.7 15.7 18.1 18.1 SWEPCo 22.0 22.0 23.4 23.4 AEGCo AEGCo, a wholly-owned subsidiary of Parent, is consolidated by AEP. AEGCo owns a 50% ownership interest in Rockport Plant, Unit 1 and leases a 50% interest in Rockport Plant, Unit 2. AEGCo sells all the output from the Rockport Plant to I&M and KPCo. AEP has agreed to provide AEGCo with the funds necessary to satisfy all of the debt obligations of AEGCo. I&M is considered to have a significant interest in AEGCo due to these transactions. I&M is exposed to losses to the extent it cannot recover the costs of AEGCo through its normal business operations. In the event AEGCo would require financing or other support outside the billings to I&M and KPCo, this financing would be provided by AEP. Total billings to I&M from AEGCo for the years ended December 31, 2020, 2019 and 2018 were $173 million, $215 million and $238 million, respectively. The carrying amounts of I&M’s liabilities associated with AEGCo as of December 31, 2020 and 2019 were $9 million and $10 million, respectively. Management estimates the maximum exposure of loss to be equal to the amount of such liability. See “Rockport Lease” section of Note 13 for additional information. Significant Equity Method Investments in Unconsolidated Entities For a discussion of the equity method of accounting, see the “Equity Investment in Unconsolidated Entities” section of Note 1. Sempra Renewables LLC In April 2019, AEP acquired a 50% interest in five wind farms in multiple states as part of the purchase of Sempra Renewables LLC. The wind farms are joint ventures with BP Wind Energy who holds the other 50% interest. All five wind farms have long-term PPAs for 100% of their energy production. One of the jointly-owned wind farms has PPAs with I&M and OPCo for a portion of its energy production. Another jointly-owned wind farm has a PPA with SWEPCo for a portion of its energy production. The joint venture wind farms are not considered VIEs and AEP is not required to consolidate them as AEP does not have a controlling financial interest. However, AEP is able to exercise significant influence over the wind farms and therefore applies the equity method of accounting. As of December 31, 2020 and 2019, AEP’s investment in the five joint venture wind farms was $376 million and $394 million, respectively. The investment includes amounts recognized in AOCI related to interest rate cash flow hedges. The investment is comprised of a historical investment of $399 million plus a basis difference of $(12) million. AEP’s equity earnings associated with the five joint venture wind farms was $2 million and a loss

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2020
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, 2020 and 2019: December 31, 2020 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Regulated Property, Plant and Equipment Generation $ 21,587.8 (a) $ — $ — $ 6,633.7 $ 5,264.7 $ — $ 1,480.7 $ 4,681.4 (a) Transmission 27,841.5 5,279.6 9,593.5 3,900.5 1,696.4 2,831.9 1,069.9 2,165.7 Distribution 23,972.1 4,580.8 — 4,464.3 2,594.6 5,708.3 2,853.0 2,382.5 Other 4,852.4 866.0 328.8 598.0 644.6 888.5 388.1 564.5 CWIP 3,815.0 (a) 614.1 1,422.6 484.6 362.4 362.3 128.7 228.3 (a) Less: Accumulated Depreciation 20,094.2 1,528.1 572.8 4,711.0 3,538.6 2,348.8 1,607.3 3,032.0 Total Regulated Property, Plant and Equipment - Net 61,974.6 9,812.4 10,772.1 11,370.1 7,024.1 7,442.2 4,313.1 6,990.4 Nonregulated Property, Plant and Equipment - Net 1,927.0 1.2 0.7 24.0 28.2 9.9 6.9 97.8 Total Property, Plant and Equipment - Net $ 63,901.6 $ 9,813.6 $ 10,772.8 $ 11,394.1 $ 7,052.3 $ 7,452.1 $ 4,320.0 $ 7,088.2 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 (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 2020 2019 2018 Functional Class of Property Annual Composite Depreciable Annual Composite Depreciable Annual Composite Depreciable (in years) (in years) (in years) Generation 2.7% - 6.3% 20 - 132 2.5% - 5.5% 20 - 132 2.4% - 4.0% 20 - 132 Transmission 2.0% - 2.6% 15 - 75 1.8% - 2.6% 15 - 81 1.6% - 2.7% 15 - 81 Distribution 2.7% - 3.7% 7 - 78 2.7% - 3.7% 7 - 78 2.7% - 3.6% 7 - 78 Other 2.8% - 11.3% 5 - 75 2.6% - 9.5% 5 - 75 2.3% - 9.8% 5 - 75 AEP Texas 2020 2019 2018 Functional Class of Property Annual Composite Depreciable Annual Composite Depreciable Annual Composite Depreciable (in years) (in years) (in years) Transmission 2.0% 50 - 75 1.8% 45 - 81 1.7% 45 - 81 Distribution 3.1% 7 - 70 3.5% 7 - 70 3.6% 7 - 70 Other 6.1% 5 - 50 6.3% 5 - 50 6.0% 5 - 50 AEPTCo 2020 2019 2018 Functional Class of Property Annual Composite Depreciable Annual Composite Depreciable Annual Composite Depreciable (in years) (in years) (in years) Transmission 2.4% 24 - 75 2.0% 24 - 75 1.9% 20 - 75 Other 6.3% 5 - 64 5.8% 5 - 64 5.6% 5 - 64 APCo 2020 2019 2018 Functional Class of Property Annual Composite Depreciable Annual Composite Depreciable Annual Composite Depreciable (in years) (in years) (in years) Generation 3.3% 35 - 118 3.2% 35 - 118 3.1% 35 - 112 Transmission 2.2% 15 - 75 1.8% 15 - 71 1.6% 15 - 68 Distribution 3.7% 12 - 57 3.7% 12 - 57 3.6% 10 - 57 Other 7.8% 5 - 55 7.2% 5 - 55 7.4% 5 - 55 I&M 2020 2019 2018 Functional Class of Property Annual Composite Depreciable Annual Composite Depreciable Annual Composite Depreciable (in years) (in years) (in years) Generation 4.6% 20 - 132 4.0% 20 - 132 3.4% 20 - 132 Transmission 2.3% 45 - 70 1.9% 50 - 73 1.8% 50 - 73 Distribution 3.4% 14 - 71 3.4% 9 - 75 3.1% 9 - 75 Other 10.2% 5 - 51 9.4% 5 - 50 8.9% 5 - 50 OPCo 2020 2019 2018 Functional Class of Property Annual Composite Depreciable Annual Composite Depreciable Annual Composite Depreciable (in years) (in years) (in years) Transmission 2.3% 39 - 60 2.3% 39 - 60 2.3% 39 - 60 Distribution 3.1% 14 - 65 3.1% 14 - 65 3.0% 14 - 65 Other 5.0% 5 - 50 4.9% 5 - 50 6.3% 5 - 50 PSO 2020 2019 2018 Functional Class of Property Annual Composite Depreciable Annual Composite Depreciable Annual Composite Depreciable (in years) (in years) (in years) Generation 3.1% 35 - 75 2.9% 35 - 75 2.9% 35 - 75 Transmission 2.2% 45 - 75 2.4% 45 - 75 2.3% 45 - 75 Distribution 2.9% 15 - 78 2.9% 15 - 78 2.9% 15 - 78 Other 5.7% 5 - 64 5.6% 5 - 64 6.3% 5 - 64 SWEPCo 2020 2019 2018 Functional Class of Property Annual Composite Depreciable Annual Composite Depreciable Annual Composite Depreciable (in years) (in years) (in years) Generation 2.7% 35 - 65 2.5% 40 - 70 2.4% 40 - 70 Transmission 2.3% 47 - 73 2.4% 50 - 73 2.2% 50 - 73 Distribution 2.7% 15 - 67 2.7% 25 - 70 2.7% 25 - 70 Other 8.5% 5 - 52 7.6% 5 - 55 8.0% 5 - 55 The following table includes the nonregulated annual composite depreciation rate ranges and nonregulated depreciable life ranges for AEP. Depreciation rate ranges and depreciable life ranges are not meaningful for nonregulated property of AEPTCo, APCo, I&M, OPCo, PSO and SWEPCo for 2020, 2019 and 2018. 2020 2019 2018 Functional Class of Property Annual Composite Depreciable Annual Composite Depreciable Annual Composite Depreciable (in years) (in years) (in years) Generation 3.6% - 4.0% 15 - 59 3.2% - 21.2% 15 - 59 3.4% - 22.3% 15 - 59 Transmission 2.5% 30 - 40 2.5% 30 - 40 2.4% 40 Distribution NA NA 2.3% 40 2.3% 40 Other 16.1% 5 - 50 (a) 17.6% 5 - 50 (a) 16.3% 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. NA Not applicable. 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. The Registrants recorded the following revisions to ARO estimates as of December 31, 2020: • In March 2020, SWEPCo recorded a revision to increase estimated ARO liabilities by $21 million primarily due to the revision in the useful life of DHLC. See Note 5 - Effects of Regulation for additional information. In September 2020, SWEPCo recorded an $18 million revision due to a reduction in estimated ash pond closure costs. • In June 2020, AEP Texas and PSO recorded a revision to decrease estimated ARO liabilities by $17 million and $5 million, respectively, due to the retirement of the Oklaunion Power Station in September 2020. See Note 5 - Effects of Regulation for additional information. • In June 2020, AGR derecognized $106 million of Conesville Plant related ARO liabilities as a result of the Environmental Liability and Property Transfer and Asset Purchase Agreement executed with a non-affiliated third-party. See Note 7 - Acquisitions and Dispositions for additional information. • In June 2020, APCo recorded a revision to increase estimated Glen Lyn Station ash disposal ARO liabilities by $199 million due to the enactment of House Bill 443. This bill requires APCo to close the ash disposal units at the retired Glen Lyn Station by removal of all coal combustion material. The legislation provides for regulatory recovery of these costs. See Note 6 - Commitments, Guarantees and Contingencies for additional information. As of December 31, 2020 and 2019, I&M’s ARO liability for nuclear decommissioning of the Cook Plant was $1.80 billion and $1.73 billion, respectively. These liabilities are reflected in Asset Retirement Obligations on I&M’s balance sheets. As of December 31, 2020 and 2019, the fair value of I&M’s assets that are legally restricted for purposes of settling decommissioning liabilities totaled $2.98 billion and $2.65 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 2020 and 2019 aggregate carrying amounts of ARO by Registrant: Company ARO as of December 31, 2019 Accretion Liabilities Liabilities Revisions in ARO as of December 31, 2020 (in millions) AEP (b)(c)(d)(e) $ 2,418.9 $ 102.4 $ 0.3 $ (188.0) $ 183.1 $ 2,516.7 AEP Texas (b)(e) 29.1 0.8 — (8.5) (16.8) 4.6 APCo (b)(e) 111.1 8.9 — (7.8) 200.9 313.1 I&M (b)(c)(e) 1,748.6 70.2 0.1 (0.2) (4.9) 1,813.8 OPCo (e) 1.8 0.1 — — — 1.9 PSO (b)(e) 52.2 3.1 — (3.1) (4.8) 47.4 SWEPCo (b)(d)(e) 212.2 10.7 — (10.9) 10.1 222.1 Company ARO as of December 31, 2018 Accretion Liabilities Liabilities Revisions in 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 (a) Unless discussed above, 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 $1.80 billion and $1.73 billion as of December 31, 2020 and 2019, respectively. (d) Includes ARO related to Sabine and DHLC. (e) Includes ARO related to asbestos removal. 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 2020 2019 2018 (in millions) AEP $ 148.1 $ 168.4 $ 132.5 AEP Texas 19.4 15.2 20.0 AEPTCo 74.0 84.3 70.6 APCo 14.6 16.6 13.2 I&M 11.5 19.4 11.9 OPCo 12.5 18.2 9.8 PSO 4.0 2.7 0.4 SWEPCo 7.7 6.8 6.0 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 2020 2019 2018 (in millions) AEP $ 66.0 $ 88.7 $ 73.6 AEP Texas 12.5 20.0 18.4 AEPTCo 25.5 32.2 26.1 APCo 7.9 9.3 8.4 I&M 5.7 8.9 7.4 OPCo 6.2 6.7 5.8 PSO 2.0 1.9 0.9 SWEPCo 3.9 4.0 4.8 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, 2020 Fuel Percent of Utility Plant Construction Accumulated (in millions) AEP Dolet Hills Power Station, Unit 1 (a) Lignite 40.2 % $ 342.4 $ 4.6 $ 295.4 Flint Creek Generating Station, Unit 1 (b) Coal 50.0 % 377.2 3.0 116.0 Pirkey Power Plant, Unit 1 (b) Lignite 85.9 % 602.8 3.7 441.0 Oklaunion Power Station (f)(g) Coal 70.3 % — — — Turk Generating Plant (b) Coal 73.3 % 1,594.3 2.8 257.3 Total $ 2,916.7 $ 14.1 $ 1,109.7 AEP Texas Oklaunion Power Station (f)(g) Coal 54.7 % $ — $ — $ — I&M Rockport Generating Plant (c)(d)(e) Coal 50.0 % $ 1,228.5 $ 19.6 $ 677.3 PSO Oklaunion Power Station (f)(g) Coal 15.6 % $ — $ — $ — SWEPCo Dolet Hills Power Station, Unit 1 (a) Lignite 40.2 % $ 342.4 $ 4.6 $ 295.4 Flint Creek Generating Station, Unit 1 (b) Coal 50.0 % 377.2 3.0 116.0 Pirkey Power Plant, Unit 1 (b) Lignite 85.9 % 602.8 3.7 441.0 Turk Generating Plant (b) Coal 73.3 % 1,594.3 2.8 257.3 Total $ 2,916.7 $ 14.1 $ 1,109.7 Registrant’s Share as of December 31, 2019 Fuel Percent of Utility Plant Construction Accumulated (in millions) AEP Dolet Hills Power Station, Unit 1 (a) Lignite 40.2 % $ 337.3 $ 6.2 $ 216.5 Flint Creek Generating Station, Unit 1 (b) Coal 50.0 % 374.3 3.4 101.1 Pirkey Power Plant, Unit 1 (b) Lignite 85.9 % 607.8 7.7 416.8 Oklaunion Power Station (f)(g) Coal 70.3 % 106.6 0.1 91.7 Turk Generating Plant (b) Coal 73.3 % 1,593.3 1.7 225.8 Total $ 3,019.3 $ 19.1 $ 1,051.9 AEP Texas Oklaunion Power Station (f)(g) Coal 54.7 % $ 351.7 $ — $ 291.9 I&M Rockport Generating Plant (c)(d)(e) Coal 50.0 % $ 1,114.2 $ 105.5 $ 586.2 PSO Oklaunion Power Station (f)(g) Coal 15.6 % $ 106.6 $ 0.1 $ 91.7 SWEPCo Dolet Hills Power Station, Unit 1 (a) Lignite 40.2 % $ 337.3 $ 6.2 $ 216.5 Flint Creek Generating Station, Unit 1 (b) Coal 50.0 % 374.3 3.4 101.1 Pirkey Power Plant, Unit 1 (b) Lignite 85.9 % 607.8 7.7 416.8 Turk Generating Plant (b) Coal 73.3 % 1,593.3 1.7 225.8 Total $ 2,912.7 $ 19.0 $ 960.2 (a) Operated by CLECO, a nonaffiliated company. (b) Operated by SWEPCo. (c) Operated by I&M. (d) 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 for additional information. (e) AEGCo owns 50% of Unit 1 with I&M and 50% of capital additions for Unit 2. (f) Operated by PSO, which owned 15.6%. Also was jointly-owned (54.7%) by AEP Texas and various nonaffiliated companies. (g) Oklaunion Power Station was retired in September 2020 and sold to a nonaffiliated third-party in October 2020. See the “Dispositions” section of Note 7 for additional information.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	12 Months Ended
	Dec. 31, 2020
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, 2020 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 $ 3,606.8 $ 2,086.9 $ — $ — $ — $ — $ 5,693.7 Commercial Revenues 2,016.2 1,048.6 — — — — 3,064.8 Industrial Revenues 2,018.0 390.1 — — — (0.7) 2,407.4 Other Retail Revenues 155.6 42.5 — — — — 198.1 Total Retail Revenues 7,796.6 3,568.1 — — — (0.7) 11,364.0 Wholesale and Competitive Retail Revenues: Generation Revenues 588.3 — — 131.9 — — 720.2 Transmission Revenues (a) 334.5 467.0 1,257.0 — — (1,006.7) 1,051.8 Renewable Generation Revenues (b) — — — 60.9 — (1.6) 59.3 Retail, Trading and Marketing Revenues (c) — — — 1,486.9 (5.5) (103.0) 1,378.4 Total Wholesale and Competitive Retail Revenues 922.8 467.0 1,257.0 1,679.7 (5.5) (1,111.3) 3,209.7 Other Revenues from Contracts with Customers (b) 163.2 157.8 22.4 2.3 92.5 (148.6) 289.6 Total Revenues from Contracts with Customers 8,882.6 4,192.9 1,279.4 1,682.0 87.0 (1,260.6) 14,863.3 Other Revenues: Alternative Revenues (b) (3.2) 70.0 (80.6) — — 7.5 (6.3) Other Revenues (b) — 83.0 — 43.6 9.8 (74.9) 61.5 Total Other Revenues (3.2) 153.0 (80.6) 43.6 9.8 (67.4) 55.2 Total Revenues $ 8,879.4 $ 4,345.9 $ 1,198.8 $ 1,725.6 $ 96.8 $ (1,328.0) $ 14,918.5 (a) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $965 million. The remaining affiliated amounts were immaterial. (b) Amounts include affiliated and nonaffiliated revenues. (c) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $103 million. The remaining affiliated amounts were immaterial. 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 807.6 — — 254.8 — — 1,062.4 Transmission Revenues (a) 292.1 435.1 1,077.2 — — (825.0) 979.4 Renewable Generation Revenues (b) — — — 57.3 — — 57.3 Retail, Trading and Marketing Revenues (c) — — — 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 (b) 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 (b) (57.9) 32.3 (20.6) — — (66.9) (113.1) Other Revenues (b) — 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. (c) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $136 million. The remaining affiliated amounts were immaterial. 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 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 (c) — — — 50.8 — — 50.8 Retail, Trading and Marketing Revenues (d) — — — 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 (c) 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 (c) (15.9) (22.2) (60.4) — — 52.7 (45.8) Other Revenues (c) (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. (d) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $121 million. The remaining affiliated amounts were immaterial. (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, 2020 AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Retail Revenues: Residential Revenues $ 563.6 $ — $ 1,250.6 $ 794.1 $ 1,523.4 $ 579.4 $ 630.8 Commercial Revenues 366.7 — 517.0 499.3 682.0 320.1 466.7 Industrial Revenues 120.1 — 553.5 547.4 270.0 221.1 328.8 Other Retail Revenues 29.5 — 67.6 6.6 13.1 66.0 9.1 Total Retail Revenues 1,079.9 — 2,388.7 1,847.4 2,488.5 1,186.6 1,435.4 Wholesale Revenues: Generation Revenues (a) — — 230.2 274.6 — 15.1 162.0 Transmission Revenues (b) 399.9 1,210.3 130.8 29.0 67.0 27.5 111.2 Total Wholesale Revenues 399.9 1,210.3 361.0 303.6 67.0 42.6 273.2 Other Revenues from Contracts with Customers (c) 48.2 22.4 59.5 85.0 109.5 34.7 26.7 Total Revenues from Contracts with Customers 1,528.0 1,232.7 2,809.2 2,236.0 2,665.0 1,263.9 1,735.3 Other Revenues: Alternative Revenues (d) 3.4 (87.0) (13.0) 5.8 66.6 2.2 3.2 Other Revenues (d) 87.5 — — — 17.5 — — Total Other Revenues 90.9 (87.0) (13.0) 5.8 84.1 2.2 3.2 Total Revenues $ 1,618.9 $ 1,145.7 $ 2,796.2 $ 2,241.8 $ 2,749.1 $ 1,266.1 $ 1,738.5 (a) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $112 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 $952 million. The remaining affiliated amounts were immaterial. (c) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $69 million primarily relating to barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial. (d) Amounts include affiliated and nonaffiliated revenues. 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 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 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 REPs 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. The AEP East Companies are parties to the 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 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, 2020. 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 2021 2022-2023 2024-2025 After 2025 Total (in millions) AEP $ 1,122.9 $ 164.1 $ 162.2 $ 161.5 $ 1,610.7 AEP Texas 465.4 — — — 465.4 AEPTCo 1,319.5 — — — 1,319.5 APCo 173.4 32.3 23.2 11.6 240.5 I&M 35.1 8.8 8.8 4.5 57.2 OPCo 68.1 — — 0.1 68.2 PSO 14.8 — — — 14.8 SWEPCo 41.6 — — — 41.6 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, 2020 and 2019. 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, 2020 and 2019. 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, 2020 and 2019. 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 2020 2019 (in millions) AEPTCo $ 81.0 $ 65.9 APCo 52.7 47.3 I&M 34.8 37.1 OPCo 45.9 33.9 PSO 7.8 9.7 SWEPCo 11.2 17.6 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, 2020 and 2019.

Goodwill

Goodwill	12 Months Ended
	Dec. 31, 2020
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, 2020 and 2019 by operating segment are as follows: Corporate and Other Generation AEP Consolidated (in millions) 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 Impairment Losses — — — Balance as of December 31, 2020 $ 37.1 $ 15.4 $ 52.5 In the fourth quarters of 2020 and 2019, 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.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2020
Subsequent Events	SUBSEQUENT EVENTS Impacts of Severe Winter Weather in February 2021 In February 2021, many of AEP’s service territories and customers were impacted by severe winter weather and extreme cold temperatures resulting in power outages, extensive damage to transmission and distribution infrastructure and disruption to the energy markets. Storm Costs (Applies to AEP, APCo and SWEPCo) Based on the information currently available, APCo, KPCo and SWEPCo currently estimate significant February 2021 storm restoration expenditures as shown in the table below. Management currently anticipates the storm restoration expenditures will be more heavily weighted towards other operation and maintenance expenses as compared to capital expenditures. Management will continue to refine these storm cost estimates as restoration efforts are completed and final costs become available. Total Estimated February 2021 (in millions) APCo $65.0 - $75.0 KPCo $75.0 - $95.0 SWEPCo $30.0 - $40.0 Management plans to seek regulatory recovery of these costs. If any of the storm costs are not recoverable, it could reduce future net income and cash flows and impact financial condition. February 2021 Severe Winter Weather Impacts in SPP (Applies to AEP, PSO and SWEPCo) The February 2021 severe winter weather also had a significant impact in SPP resulting in the declaration of Energy Emergency Alert Levels 2 and 3 for the first time in SPP’s history. The winter storm increased the demand for natural gas and restricted the available natural gas supply resulting in significantly increased market prices for natural gas power plants to meet reliability needs for the SPP electric system. From February 9, 2021, to February 20, 2021, based on the information currently available, PSO’s and SWEPCo’s preliminary estimates of natural gas expenses and purchases of electricity are as follows: PSO SWEPCo (in millions) Estimated Natural Gas Expenses $ 175.0 $ 375.0 Estimated Electricity Purchases 650.0 — $ 825.0 $ 375.0 The amounts in the table above represent preliminary estimates as of February 25, 2021, and are subject to final settlement as additional information becomes available. In addition, SPP notified PSO and SWEPCo of additional collateral requirements of approximately $868 million on a cumulative basis for the companies due March 2, 2021. Subsequently, SPP filed a waiver request with the FERC that would grant a limited waiver for Load Serving Entities to post this additional collateral requirement between February 24, 2021 and March 11, 2021. FERC approved the waiver request on February 24, 2021. PSO and SWEPCo have active fuel clauses that allow for the recovery of prudently incurred fuel and purchased power expenses. Given the significance of these costs, PSO and SWEPCo expect regulators to perform a heightened review of the costs. Management believes these costs are probable of future recovery. However, the recovery of these costs from customers may be extended over longer than usual time periods to mitigate the impact on customer bills. Nevertheless, PSO and SWEPCo’s payments to suppliers are due in March 2021. PSO and SWEPCo are evaluating financing alternatives including funding contributions from Parent and long-term debt issuances to address the timing difference between the payment to suppliers and recovery from customers. If either PSO or SWEPCo is unable to recover these fuel and purchased power expenses or recover these expenses in a timely manner, it could reduce future net income and cash flows and impact financial condition. ERCOT (Applies to AEP and AEP Texas) In response to the extreme winter weather event, the Governor of Texas issued a Declaration of a State of Disaster for all counties in Texas. While recovery from the emergency conditions is continuing, some market conditions and activities have yet to return to normal. To assist with a return to normalcy, the PUCT issued an order that placed a temporary moratorium on customer disconnections due to non-payment for transmission and distribution utilities. This moratorium will be in effect until otherwise ordered by the PUCT.

Organization and Summary of S_2

Organization and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
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.
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 one active REP 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 assets, the power from which is marketed and sold in ERCOT. Power from the Oklaunion Power Station was also marketed and sold by these nonregulated subsidiaries in ERCOT prior to its retirement in September 2020. 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.
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 statements of cash flows for OPCo include the Registrant Subsidiary and Ohio Phase-in Recovery Funding (a consolidated VIE) for the years ended December 31, 2019 and 2018. 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.
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 and APCo) Restricted Cash primarily includes funds held by trustees for the payment of securitization bonds.
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	InventoryFossil fuel inventories are carried at average cost with the exception of AGR, which is carried at the lower of average cost or net realizable value.  Materials and supplies inventories are carried at average cost.
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. The assessment is performed separately by each participating AEP subsidiary, which inherently contemplates any differences in geographical risk characteristics for the allowance. 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 based upon a 12-month rolling average of bad debt write-offs in proportion to gross accounts receivable, unless specifically identified. In addition to these processes, management contemplates available current information, as well as any reasonable and supportable forecast information, to determine if allowances for uncollectible accounts should be further adjusted in accordance with the accounting guidance for “Credit Losses.” Management’s assessments contemplate expected losses over the life of the accounts receivable.
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 on the statements of income. 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. The Registrants share the majority of their Off-system Sales margins to customers either through an active FAC or other rate mechanisms. 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 19 - 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.
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 in-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 on the statements of income. 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 loss of the parent company (Parent Company Loss Benefit) to the AEP System subsidiaries with taxable income reducing their current tax expense proportionately. The consolidated NOL of the AEP System is allocated to each company in the consolidated group with taxable losses. With the exception of the allocation of the consolidated AEP System NOL, 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 non-qualified pension plans. Substantially all AEP employees are covered by the qualified plan or both the qualified and a non-qualified 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 non-qualified pension plans. Substantially all AEP employees are covered by the qualified plan or both the qualified and a non-qualified 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 rate-making 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 25 % Fixed Income 59 % Other Investments 15 % Cash and Cash Equivalents 1 % OPEB Plans Assets Target Equity 49 % Fixed Income 49 % 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 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, 2020 and 2019, the fair value of securities on loan as part of the program was $177 million and $246 million, respectively. Cash and securities obtained as collateral exceeded the fair value of the securities loaned as of December 31, 2020 and 2019. 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.
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 debt securities in the trust funds as available-for-sale due to their long-term purpose. 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, 2020, 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 non-qualified 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 until the awards vest. Upon vesting, the performance shares are classified as permanent equity. 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 until the awards vest. 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, 2020, 2019 and 2018 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, 2020, 2019 and 2018, 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.
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, 2020
Pension and Other Postretirement Plans	Pension and OPEB Plans (Applies to all Registrants except AEPTCo) AEP sponsors a qualified pension plan and two unfunded non-qualified pension plans. Substantially all AEP employees are covered by the qualified plan or both the qualified and a non-qualified 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 non-qualified pension plans. Substantially all AEP employees are covered by the qualified plan or both the qualified and a non-qualified 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 rate-making 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, 2020
Derivatives and Hedging	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. 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 and other 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. 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. 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. 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, surety bonds 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)

Fair Value Measurements (Polici

Fair Value Measurements (Policies)	12 Months Ended
	Dec. 31, 2020
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, 2020
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 in-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 on the statements of income. 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 loss of the parent company (Parent Company Loss Benefit) to the AEP System subsidiaries with taxable income reducing their current tax expense proportionately. The consolidated NOL of the AEP System is allocated to each company in the consolidated group with taxable losses. With the exception of the allocation of the consolidated AEP System NOL, 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, 2020
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.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.

Stock-Based Compensation (Polic

Stock-Based Compensation (Policies)	12 Months Ended
	Dec. 31, 2020
Stock-based Compensation	Stock-Based Compensation Plans As of December 31, 2020, 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 non-qualified 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 until the awards vest. Upon vesting, the performance shares are classified as permanent equity. 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 until the awards vest. 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, 2020, 2019 and 2018 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, 2020, 2019 and 2018, 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 (Prior Plan), was replaced prospectively for new grants by the American Electric Power System 2015 Long-Term Incentive Plan (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, 2020, 6,712,148 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. Each share issued for any other award that settles in AEP stock reduces 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.Unrecognized compensation cost related to unvested share-based arrangements will change as the fair value of performance shares is 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 1.39 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 tax withholding obligations.
Performance Units [Member]
Stock-based Compensation	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 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. Performance shares are recorded as mezzanine equity on the balance sheets until the vesting date and compensation cost is calculated at fair value based on metrics for each grant. Performance shares granted in 2020 had three performance metrics: (a) three-year cumulative operating earnings per-share with a 50% weight, (b) total shareholder return with a 40% weight and (c) non-emitting generation capacity as a percentage of total owned and purchased capacity with a 10% weight. Performance shares granted prior to 2020 had two equally-weighted performance metrics: (a) three-year cumulative operating earnings per-share and (b) total shareholder return. The three-year cumulative operating earnings per-share metric and non-emitting generating capacity metric are adjusted quarterly for changes in performance relative to a target approved by the HR Committee. The total shareholder return metric is measured relative to a peer group of similar companies and is based on a third-party Monte Carlo valuation. The value related to this metric does not change over the three-year vesting period.
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 was 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 the 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. These balances are also paid in cash upon termination of board service or up to 10 years later if the participant so elects. 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, 2020
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, 2020
Property, Plant and Equipment	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.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	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, 2020
Reconciliation of Cash, Cash Equivalents and Restricted Cash	December 31, 2020 AEP AEP Texas APCo (in millions) Cash and Cash Equivalents $ 392.7 $ 0.1 $ 5.8 Restricted Cash 45.6 28.7 16.9 Total Cash, Cash Equivalents and Restricted Cash $ 438.3 $ 28.8 $ 22.7 December 31, 2019 AEP AEP Texas APCo (in millions) Cash and Cash Equivalents $ 246.8 $ 3.1 $ 3.3 Restricted Cash 185.8 154.7 23.5 Total Cash, Cash Equivalents and Restricted Cash $ 432.6 $ 157.8 $ 26.8
Significant Customers	Significant Customers of AEP Texas: Reliant Energy, Direct Energy and TXU Energy (a) 2020 2019 2018 Percentage of Total Revenues 46 % 48 % 45 % Percentage of Accounts Receivable – Customers 40 % 43 % 35 % (a) In January 2021, NRG Energy, parent company of Reliant Energy, completed a deal to purchase Direct Energy from Centrica. Significant Customers of AEPTCo: AEP Subsidiaries 2020 2019 2018 Percentage of Total Revenues 78 % 79 % 77 % Percentage of Total Accounts Receivable 78 % 78 % 84 %
Target Asset Allocations	Pension Plan Assets Target Equity 25 % Fixed Income 59 % Other Investments 15 % Cash and Cash Equivalents 1 % OPEB Plans Assets Target Equity 49 % Fixed Income 49 % Cash and Cash Equivalents 2 %
Basic and Diluted EPS Calculations	Years Ended December 31, 2020 2019 2018 (in millions, except per-share data) $/share $/share $/share Earnings Attributable to AEP Common Shareholders $ 2,200.1 $ 1,921.1 $ 1,923.8 Weighted-Average Number of Basic AEP Common Shares Outstanding 495.7 $ 4.44 493.7 $ 3.89 492.8 $ 3.90 Weighted-Average Dilutive Effect of Stock-Based Awards 1.5 (0.02) 1.6 (0.01) 1.0 — Weighted-Average Number of Diluted AEP Common Shares Outstanding 497.2 $ 4.42 495.3 $ 3.88 493.8 $ 3.90
Supplementary Information	2020 Depreciation and Amortization AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Depreciation and Amortization of Property, Plant and Equipment $ 2,487.5 $ 364.2 $ 249.0 $ 507.8 $ 393.3 $ 275.0 $ 171.9 $ 271.2 Amortization of Certain Securitized Assets 171.3 171.3 — — — — — — Amortization of Regulatory Assets and Liabilities 24.0 (5.7) — (0.3) 18.3 1.6 1.6 1.5 Total Depreciation and Amortization $ 2,682.8 $ 529.8 $ 249.0 $ 507.5 $ 411.6 $ 276.6 $ 173.5 $ 272.7 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 Years Ended December 31, Cash Flow Information 2020 2019 2018 (in millions) Cash Paid (Received) for: Interest, Net of Capitalized Amounts $ 1,029.1 $ 1,022.5 $ 939.3 Income Taxes (49.1) 6.1 (24.7) Noncash Investing and Financing Activities: Acquisitions Under Finance Leases 44.2 87.5 55.6 Construction Expenditures Included in Current Liabilities as of December 31, 975.4 1,341.1 1,120.4 Construction Expenditures Included in Noncurrent Liabilities as of December 31, 5.5 — — Acquisition of Nuclear Fuel Included in Current Liabilities as of December 31, 33.4 0.1 4.0 Noncash Contribution of Assets by Noncontrolling Interest — — 84.0 Expected Reimbursement for Spent Nuclear Fuel Dry Cask Storage 2.6 0.3 2.2 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 — Forward Equity Purchase Contracts Included in Current and Noncurrent Liabilities as of December 31, 110.6 47.3 —

Comprehensive Income (Tables)

Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2020
Changes in Accumulated Other Comprehensive Income (Loss) by Component	AEP Cash Flow Hedges Pension and OPEB For the Year Ended December 31, 2020 Commodity Interest Rate Amortization of Deferred Costs Changes in Funded Status Total (in millions) Balance in AOCI as of December 31, 2019 $ (103.5) $ (11.5) $ 130.7 $ (163.4) $ (147.7) Change in Fair Value Recognized in AOCI (89.2) (39.9) (a) — 62.7 (66.4) Amount of (Gain) Loss Reclassified from AOCI Generation & Marketing Revenues (b) (0.4) — — — (0.4) Purchased Electricity for Resale (b) 167.6 — — — 167.6 Interest Expense (b) — 4.9 — — 4.9 Amortization of Prior Service Cost (Credit) — — (19.2) — (19.2) Amortization of Actuarial (Gains) Losses — — 10.3 — 10.3 Reclassifications from AOCI, before Income Tax (Expense) Benefit 167.2 4.9 (8.9) — 163.2 Income Tax (Expense) Benefit 35.1 1.0 (1.9) — 34.2 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 132.1 3.9 (7.0) — 129.0 Net Current Period Other Comprehensive Income (Loss) 42.9 (36.0) (7.0) 62.7 62.6 Balance in AOCI as of December 31, 2020 $ (60.6) $ (47.5) $ 123.7 $ (100.7) $ (85.1) 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) Cash Flow Hedges Pension and OPEB For the Year Ended December 31, 2018 Commodity Interest Rate Securities 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) AEP Texas Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2020 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2019 $ (3.4) $ 4.9 $ (14.3) $ (12.8) Change in Fair Value Recognized in AOCI 0.1 — 2.6 2.7 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) 1.1 0.2 2.6 3.9 Balance in AOCI as of December 31, 2020 $ (2.3) $ 5.1 $ (11.7) $ (8.9) 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 ASU 2018-02 Adoption — — — — 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) APCo Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2020 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2019 $ 0.9 $ 9.2 $ (5.1) $ 5.0 Change in Fair Value Recognized in AOCI (0.7) — 7.7 7.0 Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (1.3) — — (1.3) Amortization of Prior Service Cost (Credit) — (5.3) — (5.3) Amortization of Actuarial (Gains) Losses — 0.5 — 0.5 Reclassifications from AOCI, before Income Tax (Expense) Benefit (1.3) (4.8) — (6.1) Income Tax (Expense) Benefit (0.3) (1.0) — (1.3) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (1.0) (3.8) — (4.8) Net Current Period Other Comprehensive Income (Loss) (1.7) (3.8) 7.7 2.2 Balance in AOCI as of December 31, 2020 $ (0.8) $ 5.4 $ 2.6 $ 7.2 Pension and OPEB Amortization Changes in Cash Flow Hedges - 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 Amortization Changes in Cash Flow Hedges of Deferred Funded For the Year Ended December 31, 2018 Commodity Interest 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) I&M Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2020 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2019 $ (9.9) $ 4.9 $ (6.6) $ (11.6) Change in Fair Value Recognized in AOCI — — 3.1 3.1 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 — 0.7 — 0.7 Reclassifications from AOCI, before Income Tax (Expense) Benefit 2.0 (0.1) — 1.9 Income Tax (Expense) Benefit 0.4 — — 0.4 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 1.6 (0.1) — 1.5 Net Current Period Other Comprehensive Income (Loss) 1.6 (0.1) 3.1 4.6 Balance in AOCI as of December 31, 2020 $ (8.3) $ 4.8 $ (3.5) $ (7.0) 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) OPCo Cash Flow Hedge – For the Year Ended December 31, 2020 Interest Rate (in millions) Balance in AOCI as of December 31, 2019 $ — Change in Fair Value Recognized in AOCI — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) — Reclassifications from AOCI, before Income Tax (Expense) Benefit — Income Tax (Expense) Benefit — Reclassifications from AOCI, Net of Income Tax (Expense) Benefit — Net Current Period Other Comprehensive Income (Loss) — Balance in AOCI as of December 31, 2020 $ — 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 PSO Cash Flow Hedge – For the Year Ended December 31, 2020 Interest Rate (in millions) Balance in AOCI as of December 31, 2019 $ 1.1 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, 2020 $ 0.1 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 SWEPCo Pension and OPEB Amortization Changes in Cash Flow Hedge – of Deferred Funded For the Year Ended December 31, 2020 Interest Rate Costs Status Total (in millions) Balance in AOCI as of December 31, 2019 $ (1.8) $ (1.3) $ 1.8 $ (1.3) Change in Fair Value Recognized in AOCI — — 3.2 3.2 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 — 0.1 — 0.1 Reclassifications from AOCI, before Income Tax (Expense) Benefit 1.9 (1.9) — — Income Tax (Expense) Benefit 0.4 (0.4) — — Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 1.5 (1.5) — — Net Current Period Other Comprehensive Income (Loss) 1.5 (1.5) 3.2 3.2 Balance in AOCI as of December 31, 2020 $ (0.3) $ (2.8) $ 5.0 $ 1.9 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) (a) The change in fair value includes $6 million and $4 million related to AEP's investment in joint venture wind farms acquired as part of the purchase of Sempra Renewables LLC for the years ended December 31, 2020 and 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, 2020
Regulated Generating Units to be Retired	Plant Net Accelerated Depreciation Regulatory Asset Cost of Removal Projected Current Authorized Annual (dollars in millions) Northeastern Plant, Unit 3 $ 198.4 $ 110.4 $ 19.8 (b) 2026 (c) $ 14.9 Dolet Hills Power Station 74.4 71.2 24.0 2021 (d) 60.8 Pirkey Power Plant 199.5 12.2 38.7 2023 (e) 13.8 Welsh Plant, Units 1 and 3 549.8 3.6 57.6 (f) 2028 (g) 33.3 (a) Represents the amount of annual depreciation that has been collected from customers over the prior 12-month period. (b) Includes Northeastern Plant, Unit 4, which was retired in 2016. Removal of Northeastern Plant, Unit 4, will be performed with Northeastern Plant, Unit 3, after retirement. (c) Northeastern Plant, Unit 3 is currently being recovered through 2040. (d) Dolet Hills Power Station is current being recovered through 2026 in the Louisiana jurisdiction and through 2046 in the Arkansas and Texas jurisdictions. (e) Pirkey Power Plant is currently being recovered through 2025 in the Louisiana jurisdiction and through 2045 in the Arkansas and Texas jurisdictions. (f) Includes Welsh Plant, Unit 2, which was retired in 2016. Removal of Welsh Plant, Unit 2, will be performed with Welsh Plant, Units 1 and 3, after retirement.
Regulatory Assets	AEP December 31, Remaining Recovery Period 2020 2019 Current Regulatory Assets (in millions) Under-recovered Fuel Costs - earns a return $ 41.4 $ 44.7 1 year Under-recovered Fuel Costs - does not earn a return 49.3 48.2 1 year Total Current Regulatory Assets $ 90.7 $ 92.9 Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Earning a Return Dolet Hills Power Station Accelerated Depreciation $ 71.2 $ — Kentucky Deferred Purchased Power Expenses 41.3 30.2 Plant Retirement Costs - Unrecovered Plant, Louisiana 35.2 35.2 Oklaunion Power Station Accelerated Depreciation 34.4 27.4 Other Regulatory Assets Pending Final Regulatory Approval 38.6 0.7 Total Regulatory Assets Currently Earning a Return 220.7 93.5 Regulatory Assets Currently Not Earning a Return Storm-Related Costs 134.2 7.2 Plant Retirement Costs - Asset Retirement Obligation Costs 25.9 30.1 COVID-19 24.9 — Vegetation Management Program - AEP Texas 3.8 29.4 Other Regulatory Assets Pending Final Regulatory Approval 32.7 21.5 Total Regulatory Assets Currently Not Earning a Return 221.5 88.2 Total Regulatory Assets Pending Final Regulatory Approval 442.2 181.7 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Unrecovered Plant (a) 713.1 690.5 23 years Plant Retirement Costs - Asset Retirement Obligation Costs 107.1 87.4 20 years Meter Replacement Costs 55.5 65.4 7 years Ohio Distribution Decoupling 46.6 31.4 2 years Environmental Control Projects 38.6 41.0 20 years Rockport Plant Dry Sorbent Injection System and Selective Catalytic Reduction 34.4 13.5 8 years Cook Plant Uprate Project 30.2 32.6 13 years Storm-Related Costs 11.5 21.3 2 years Advanced Metering System — 26.5 Other Regulatory Assets Approved for Recovery 94.4 79.6 various Total Regulatory Assets Currently Earning a Return 1,131.4 1,089.2 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 1,088.6 1,309.8 12 years Plant Retirement Costs - Asset Retirement Obligation Costs 212.7 28.8 22 years Unamortized Loss on Reacquired Debt 120.0 129.0 28 years Unrealized Loss on Forward Commitments 111.3 106.8 12 years Vegetation Management 67.8 43.6 5 years Cook Plant Nuclear Refueling Outage Levelization 39.5 63.8 2 years PJM/SPP Annual Formula Rate True-up 33.0 7.3 2 years Postemployment Benefits 29.1 34.2 3 years OVEC Purchased Power 27.4 1.5 2 years Fuel and Purchased Power Adjustment Rider 24.0 7.1 2 years Medicare Subsidy 18.6 23.2 4 years Other Regulatory Assets Approved for Recovery 181.4 132.8 various Total Regulatory Assets Currently Not Earning a Return 1,953.4 1,887.9 Total Regulatory Assets Approved for Recovery 3,084.8 2,977.1 Total Noncurrent Regulatory Assets $ 3,527.0 $ 3,158.8 (a) Northeastern Plant, Unit 3 is approved for recovery through 2040, but expected to retire in 2026. PSO records a regulatory asset for accelerated depreciation. See “Regulated Generating Units to be Retired” section above for additional information. AEP Texas December 31, Remaining Regulatory Assets: 2020 2019 (in millions) Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Earning a Return Advanced Metering System $ 16.3 $ — Total Regulatory Assets Currently Earning a Return 16.3 — Regulatory Assets Currently Not Earning a Return COVID-19 10.5 — Vegetation Management Program 3.8 29.4 Other Regulatory Assets Pending Final Regulatory Approval 2.3 1.4 Total Regulatory Assets Currently Not Earning a Return 16.6 30.8 Total Regulatory Assets Pending Final Regulatory Approval 32.9 30.8 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Meter Replacement Costs 29.3 35.2 6 years Advanced Metering System — 26.5 Total Regulatory Assets Currently Earning a Return 29.3 61.7 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 145.0 172.0 12 years Vegetation Management Program 22.4 — 5 years Storm-Related Costs 17.1 — 4 years Peak Demand Reduction/Energy Efficiency 7.7 3.5 2 years Other Regulatory Assets Approved for Recovery 12.4 12.6 various Total Regulatory Assets Currently Not Earning a Return 204.6 188.1 Total Regulatory Assets Approved for Recovery 233.9 249.8 Total Noncurrent Regulatory Assets $ 266.8 $ 280.6 AEPTCo December 31, Remaining Regulatory Assets: 2020 2019 (in millions) Noncurrent Regulatory Assets Regulatory assets approved for recovery: Regulatory Assets Currently Not Earning a Return PJM/SPP Annual Formula Rate True-up $ 15.1 $ 4.2 2 years Total Regulatory Assets Approved for Recovery 15.1 4.2 Total Noncurrent Regulatory Assets $ 15.1 $ 4.2 APCo December 31, Remaining Regulatory Assets: 2020 2019 (in millions) Current Regulatory Assets Under-recovered Fuel Costs, Virginia - earns a return $ 3.3 $ 36.8 1 year Under-recovered Fuel Costs - does not earn a return 2.0 5.7 1 year Total Current Regulatory Assets $ 5.3 $ 42.5 Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Earning a Return COVID-19 - Virginia $ 3.7 $ — Plant Retirement Costs - Materials and Supplies — 0.5 Total Regulatory Assets Currently Earning a Return 3.7 0.5 Regulatory Assets Currently Not Earning a Return Plant Retirement Costs - Asset Retirement Obligation Costs 25.9 30.1 Environmental Expense Deferral - Virginia 9.3 — COVID-19 - West Virginia 1.5 — Other Regulatory Assets Pending Final Regulatory Approval 3.4 — Total Regulatory Assets Currently Not Earning a Return 40.1 30.1 Total Regulatory Assets Pending Final Regulatory Approval 43.8 30.6 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Unrecovered Plant (a) 122.4 86.4 23 years Other Regulatory Assets Approved for Recovery 1.0 0.5 various Total Regulatory Assets Currently Earning a Return 123.4 86.9 Regulatory Assets Currently Not Earning a Return Plant Retirement Costs - Asset Retirement Obligation Costs 202.7 — 15 years Pension and OPEB Funded Status 114.4 160.8 12 years Unamortized Loss on Reacquired Debt 82.1 85.5 25 years Vegetation Management Program - West Virginia 45.4 43.6 2 years Virginia Transmission Rate Adjustment Clause 18.8 — 2 years Peak Demand Reduction/Energy Efficiency 16.8 19.5 6 years Postemployment Benefits 13.5 15.9 3 years PJM Annual Formula Rate True-up 12.7 — 2 years Other Regulatory Assets Approved for Recovery 12.7 14.4 various Total Regulatory Assets Currently Not Earning a Return 519.1 339.7 Total Regulatory Assets Approved for Recovery 642.5 426.6 Total Noncurrent Regulatory Assets $ 686.3 $ 457.2 (a) December 31, 2020 amount includes Virginia and West Virginia jurisdictions. December 31, 2019 amount includes West Virginia jurisdiction. I&M December 31, Remaining Regulatory Assets: 2020 2019 (in millions) Current Regulatory Assets Under-recovered Fuel Costs - earns a return $ 5.4 $ 3.0 1 year Total Current Regulatory Assets $ 5.4 $ 3.0 Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Earning a Return Other Regulatory Assets Pending Final Regulatory Approval $ 0.5 $ — Total Regulatory Assets Currently Earning a Return 0.5 — Regulatory Assets Currently Not Earning a Return COVID-19 3.8 — Cook Plant Study Costs — 7.6 Other Regulatory Assets Pending Final Regulatory Approval — 0.1 Total Regulatory Assets Currently Not Earning a Return 3.8 7.7 Total Regulatory Assets Pending Final Regulatory Approval 4.3 7.7 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Unrecovered Plant 191.5 214.9 8 years Rockport Plant Dry Sorbent Injection System and Selective Catalytic Reduction 34.4 13.5 8 years Cook Plant Uprate Project 30.2 32.6 13 years Deferred Cook Plant Life Cycle Management Project Costs 14.1 15.1 14 years Cook Plant Turbine 11.1 13.4 18 years Cook Plant Study Costs - Indiana 10.1 — 15 years Other Regulatory Assets Approved for Recovery 7.0 6.9 various Total Regulatory Assets Currently Earning a Return 298.4 296.4 Regulatory Assets Currently Not Earning a Return Cook Plant Nuclear Refueling Outage Levelization 39.5 63.8 2 years Pension and OPEB Funded Status 25.7 67.5 12 years Unamortized Loss on Reacquired Debt 15.7 17.2 28 years Postemployment Benefits 4.9 7.2 3 years Other Regulatory Assets Approved for Recovery 16.3 22.3 various Total Regulatory Assets Currently Not Earning a Return 102.1 178.0 Total Regulatory Assets Approved for Recovery 400.5 474.4 Total Noncurrent Regulatory Assets $ 404.8 $ 482.1 OPCo December 31, Remaining Regulatory Assets: 2020 2019 (in millions) Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Not Earning a Return COVID-19 $ 4.4 $ — Storm-Related Costs 4.0 — Other Regulatory Assets Pending Final Regulatory Approval — 0.1 Total Regulatory Assets Pending Final Regulatory Approval 8.4 0.1 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Ohio Distribution Decoupling 46.6 31.4 2 years Ohio Basic Transmission Cost Rider 12.3 — 2 years Other Regulatory Assets Approved for Recovery 1.3 — various Total Regulatory Assets Currently Earning a Return 60.2 31.4 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 130.7 167.3 12 years Unrealized Loss on Forward Commitments 110.0 103.6 12 years OVEC Purchased Power 27.4 1.5 2 years Smart Grid Costs 19.2 13.7 2 years Distribution Investment Rider 7.4 10.9 2 years Postemployment Benefits 6.7 7.6 3 years Other Regulatory Assets Approved for Recovery 15.8 15.7 various Total Regulatory Assets Currently Not Earning a Return 317.2 320.3 Total Regulatory Assets Approved for Recovery 377.4 351.7 Total Noncurrent Regulatory Assets $ 385.8 $ 351.8 PSO December 31, Remaining 2020 2019 Regulatory Assets: (in millions) Current Regulatory Assets Under-recovered Fuel Costs - earns a return $ 30.1 $ — 1 year Total Current Regulatory Assets $ 30.1 $ — Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Earning a Return Oklaunion Power Station Accelerated Depreciation $ 34.4 $ 27.4 Total Regulatory Assets Currently Earning a Return 34.4 27.4 Regulatory Assets Currently Not Earning a Return Storm-Related Costs 15.8 7.2 COVID-19 0.3 — Total Regulatory Assets Currently Not Earning a Return 16.1 7.2 Total Regulatory Assets Pending Final Regulatory Approval 50.5 34.6 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Unrecovered Plant (a) 180.8 167.0 20 years Environmental Control Projects 26.5 27.8 20 years Meter Replacement Costs 26.2 30.2 7 years Storm-Related Costs 11.5 21.3 2 years Red Rock Generating Facility 8.2 8.4 36 years Other Regulatory Assets Approved for Recovery 0.5 0.6 various Total Regulatory Assets Currently Earning a Return 253.7 255.3 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 52.3 73.4 12 years Unamortized Loss on Reacquired Debt 6.1 6.5 18 years Other Regulatory Assets Approved for Recovery 12.4 5.4 various Total Regulatory Assets Currently Not Earning a Return 70.8 85.3 Total Regulatory Assets Approved for Recovery 324.5 340.6 Total Noncurrent Regulatory Assets $ 375.0 $ 375.2 (a) Northeastern Plant, Unit 3 is approved for recovery through 2040, but expected to retire in 2026. PSO records a regulatory asset for accelerated depreciation. See “Regulated Generating Units to be Retired” section above for additional information. SWEPCo December 31, Remaining 2020 2019 Regulatory Assets: (in millions) Current Regulatory Assets Under-recovered Fuel Costs - earns a return (a) $ 2.6 $ 4.9 1 year Total Current Regulatory Assets $ 2.6 $ 4.9 Noncurrent Regulatory Assets Regulatory assets pending final regulatory approval: Regulatory Assets Currently Earning a Return Dolet Hills Power Station Accelerated Depreciation $ 71.2 $ — Plant Retirement Costs - Unrecovered Plant, Louisiana 35.2 35.2 Pirkey Power Plant Accelerated Depreciation 12.2 — Welsh Plant, Units 1 and 3 Accelerated Depreciation 3.6 — Other Regulatory Assets Pending Final Regulatory Approval 2.2 0.2 Total Regulatory Assets Currently Earning a Return 124.4 35.4 Regulatory Assets Currently Not Earning a Return Storm-Related Costs 99.3 — Asset Retirement Obligation - Louisiana 9.1 7.2 Other Regulatory Assets Pending Final Regulatory Approval 14.5 3.7 Total Regulatory Assets Currently Not Earning a Return 122.9 10.9 Total Regulatory Assets Pending Final Regulatory Approval 247.3 46.3 Regulatory assets approved for recovery: Regulatory Assets Currently Earning a Return Plant Retirement Costs - Unrecovered Plant, Arkansas 14.4 15.1 22 years Environmental Controls Projects 12.1 13.2 12 years Other Regulatory Assets Approved for Recovery 7.1 8.9 various Total Regulatory Assets Currently Earning a Return 33.6 37.2 Regulatory Assets Currently Not Earning a Return Pension and OPEB Funded Status 89.1 102.6 12 years Plant Retirement Costs - Unrecovered Plant, Texas 16.1 16.6 21 years Other Regulatory Assets Approved for Recovery 17.0 19.7 various Total Regulatory Assets Currently Not Earning a Return 122.2 138.9 Total Regulatory Assets Approved for Recovery 155.8 176.1 Total Noncurrent Regulatory Assets $ 403.1 $ 222.4
Regulatory Liabilities	AEP Texas December 31, Remaining Regulatory Liabilities: 2020 2019 (in millions) Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits Regulatory liabilities pending final regulatory determination: Regulatory Liabilities Currently Paying a Return Other Regulatory Liabilities Pending Final Regulatory Determination $ 2.5 $ — Total Regulatory Liabilities Currently Paying a Return 2.5 — Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property — 274.9 Excess ADIT that is Not Subject to Rate Normalization Requirements (8.2) 87.1 Total Income Tax Related Regulatory Liabilities (8.2) 362.0 Total Regulatory Liabilities Pending Final Regulatory Determination (5.7) 362.0 Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs 718.3 689.6 (b) Other Regulatory Liabilities Approved for Payment 5.3 10.1 various Total Regulatory Liabilities Currently Paying a Return 723.6 699.7 Regulatory Liabilities Currently Not Paying a Return Transition and Restoration Charges 48.2 50.5 9 years Deferred Investment Tax Credits 8.5 9.6 20 years Other Regulatory Liabilities Approved for Payment 1.2 4.8 various Total Regulatory Liabilities Currently Not Paying a Return 57.9 64.9 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 506.0 236.5 (c) Excess ADIT that is Not Subject to Rate Normalization Requirements 41.7 — 1 years Income Taxes Subject to Flow Through (52.7) (46.2) 28 years Total Income Tax Related Regulatory Liabilities 495.0 190.3 Total Regulatory Liabilities Approved for Payment 1,276.5 954.9 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 1,270.8 $ 1,316.9 (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. (b) Relieved as removal costs are incurred. (c) Refunded using ARAM. AEPTCo December 31, Remaining Regulatory Liabilities: 2020 2019 (in millions) Noncurrent Regulatory Liabilities Regulatory Liabilities Currently Paying a Return Asset Removal Costs $ 198.6 $ 141.0 (b) Total Regulatory Liabilities Currently Paying a Return 198.6 141.0 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 531.5 535.7 (c) Excess ADIT that is Not Subject to Rate Normalization Requirements (30.6) (35.4) 8 years Income Taxes Subject to Flow Through (117.7) (100.4) 38 years Total Income Tax Related Regulatory Liabilities 383.2 399.9 Total Regulatory Liabilities Approved for Payment 581.8 540.9 Total Noncurrent Regulatory Liabilities $ 581.8 $ 540.9 (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. (b) Relieved as removal costs are incurred. (c) Refunded using ARAM. APCo December 31, Remaining Regulatory Liabilities: 2020 2019 (in millions) Noncurrent Regulatory Liabilities and Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs $ 678.9 $ 635.3 (b) Deferred Investment Tax Credits 0.3 0.5 33 years Total Regulatory Liabilities Currently Paying a Return 679.2 635.8 Regulatory Liabilities Currently Not Paying a Return 2017-2019 Virginia Triennial Revenue Provision 44.2 — 28 years PJM Transmission Enhancement Refund 16.3 19.5 5 years Virginia Transmission Rate Adjustment Clause — 28.1 Other Regulatory Liabilities Approved for Payment 12.3 18.0 various Total Regulatory Liabilities Currently Not Paying a Return 72.8 65.6 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 690.0 718.9 (c) Excess ADIT that is Not Subject to Rate Normalization Requirements 139.1 210.7 8 years Income Taxes Subject to Flow Through (356.4) (362.3) 24 years Total Income Tax Related Regulatory Liabilities 472.7 567.3 Total Regulatory Liabilities Approved for Payment 1,224.7 1,268.7 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 1,224.7 $ 1,268.7 (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. (b) Relieved as removal costs are incurred. (c) Refunded using ARAM. I&M December 31, Remaining Regulatory Liabilities: 2020 2019 (in millions) Current Regulatory Liabilities Over-recovered Fuel Costs, Indiana - does not pay a return $ 20.8 $ 6.1 1 year Total Current Regulatory Liabilities $ 20.8 $ 6.1 Noncurrent Regulatory Liabilities and Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs $ 168.2 $ 166.7 (b) Other Regulatory Liabilities Approved for Payment 17.4 0.3 various Total Regulatory Liabilities Currently Paying a Return 185.6 167.0 Regulatory Liabilities Currently Not Paying a Return Excess Nuclear Decommissioning Funding 1,476.6 1,236.0 (c) Spent Nuclear Fuel 43.1 43.6 (c) Deferred Investment Tax Credits 21.3 25.8 19 years PJM Costs and Off-system Sales Margin Sharing - Indiana 13.3 17.0 2 years PJM Transmission Enhancement Refund 9.9 11.8 5 years Deferred Gain on Sale of Rockport Unit 2 7.2 10.9 2 years Other Regulatory Liabilities Approved for Payment 30.1 24.9 various Total Regulatory Liabilities Currently Not Paying a Return 1,601.5 1,370.0 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 450.6 470.9 (d) Excess ADIT that is Not Subject to Rate Normalization Requirements 136.2 184.5 4 years Income Taxes Subject to Flow Through (332.0) (301.0) 20 years Total Income Tax Related Regulatory Liabilities 254.8 354.4 Total Regulatory Liabilities Approved for Payment 2,041.9 1,891.4 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 2,041.9 $ 1,891.4 (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. (b) Relieved as removal costs are incurred. (c) Relieved when plant is decommissioned. (d) Refunded using ARAM. OPCo December 31, Remaining 2020 2019 Regulatory Liabilities: (in millions) Current Regulatory Liabilities Over-recovered Fuel Costs - does not pay a return $ 3.9 $ 2.8 1 year Total Current Regulatory Liabilities $ 3.9 $ 2.8 Noncurrent Regulatory Liabilities and 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 458.4 446.3 (b) Ohio Basic Transmission Cost Rider — 37.2 Other Regulatory Liabilities Approved for Payment — 1.3 Total Regulatory Liabilities Currently Paying a Return 458.4 484.8 Regulatory Liabilities Currently Not Paying a Return PJM Transmission Enhancement Refund 24.5 29.4 5 years Peak Demand Reduction/Energy Efficiency 19.9 19.7 2 years Ohio Enhanced Service Reliability Plan 5.7 29.7 2 years Other Regulatory Liabilities Approved for Payment 0.7 2.9 various Total Regulatory Liabilities Currently Not Paying a Return 50.8 81.7 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 334.6 341.6 (c) Excess ADIT that is Not Subject to Rate Normalization Requirements 223.9 252.3 8 years Income Taxes Subject to Flow Through (62.7) (69.7) 29 years Total Income Tax Related Regulatory Liabilities 495.8 524.2 Total Regulatory Liabilities Approved for Payment 1,005.0 1,090.7 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 1,005.2 $ 1,090.9 (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. (b) Relieved as removal costs are incurred. (c) Refunded using ARAM. PSO December 31, Remaining 2020 2019 Regulatory Liabilities: (in millions) Current Regulatory Liabilities Over-recovered Fuel Costs - pays a return $ — $ 63.9 Total Current Regulatory Liabilities $ — $ 63.9 Noncurrent Regulatory Liabilities and Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs $ 289.9 $ 286.8 (b) Total Regulatory Liabilities Currently Paying a Return 289.9 286.8 Regulatory Liabilities Currently Not Paying a Return Deferred Investment Tax Credits 51.0 51.5 24 years Other Regulatory Liabilities Approved for Payment 1.3 4.7 various Total Regulatory Liabilities Currently Not Paying a Return 52.3 56.2 Income Tax Related Regulatory Liabilities (a) Excess ADIT Associated with Certain Depreciable Property 397.0 405.8 (c) Excess ADIT that is Not Subject to Rate Normalization Requirements 71.3 96.3 4 years Income Taxes Subject to Flow Through (8.3) (7.9) 27 years Total Income Tax Related Regulatory Liabilities 460.0 494.2 Total Regulatory Liabilities Approved for Payment 802.2 837.2 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 802.2 $ 837.2 (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. (b) Relieved as removal costs are incurred. (c) Refunded using ARAM. SWEPCo December 31, Remaining 2020 2019 Regulatory Liabilities: (in millions) Current Regulatory Liabilities Over-recovered Fuel Costs - pays a return (a) $ 37.6 $ 13.6 1 year Total Current Regulatory Liabilities $ 37.6 $ 13.6 Noncurrent Regulatory Liabilities and Regulatory liabilities pending final regulatory determination: Income Tax Related Regulatory Liabilities (b) Excess ADIT Associated with Certain Depreciable Property $ 291.6 $ 297.0 Excess ADIT that is Not Subject to Rate Normalization Requirements 21.8 22.7 Total Regulatory Liabilities Pending Final Regulatory Determination 313.4 319.7 Regulatory liabilities approved for payment: Regulatory Liabilities Currently Paying a Return Asset Removal Costs 470.9 453.4 (c) Other Regulatory Liabilities Approved for Payment 2.4 2.8 various Total Regulatory Liabilities Currently Paying a Return 473.3 456.2 Regulatory Liabilities Currently Not Paying a Return Peak Demand Reduction/Energy Efficiency 5.2 6.0 2 years Deferred Investment Tax Credits 1.8 3.1 10 years Other Regulatory Liabilities Approved for Payment 1.2 1.7 various Total Regulatory Liabilities Currently Not Paying a Return 8.2 10.8 Income Tax Related Regulatory Liabilities (b) Excess ADIT Associated with Certain Depreciable Property 332.5 339.4 (d) Excess ADIT that is Not Subject to Rate Normalization Requirements 11.5 27.8 (e) Income Taxes Subject to Flow Through (275.5) (261.6) 28 years Total Income Tax Related Regulatory Liabilities 68.5 105.6 Total Regulatory Liabilities Approved for Payment 550.0 572.6 Total Noncurrent Regulatory Liabilities and Deferred Investment Tax Credits $ 863.4 $ 892.3 (a) December 31, 2020 amount includes Arkansas and Texas jurisdictions. December 31, 2019 amount includes Texas and Louisiana jurisdictions. (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. (c) Relieved as removal costs are incurred. (d) Refunded using ARAM. (e) Current balance represents revisions to balances for jurisdictions having previously issued orders on treatment for refund, refund period to be addressed in future proceedings.

Commitments, Guarantees and C_2

Commitments, Guarantees and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Contractual Commitments	Contractual Commitments - AEP Less Than 2-3 Years 4-5 Years After Total (in millions) Fuel Purchase Contracts (a) $ 763.9 $ 715.1 $ 212.9 $ 381.5 $ 2,073.4 Energy and Capacity Purchase Contracts 211.6 291.8 277.0 928.5 1,708.9 Total $ 975.5 $ 1,006.9 $ 489.9 $ 1,310.0 $ 3,782.3 Contractual Commitments - APCo Less Than 2-3 Years 4-5 Years After Total (in millions) Fuel Purchase Contracts (a) $ 362.8 $ 217.6 $ 11.6 $ 16.3 $ 608.3 Energy and Capacity Purchase Contracts 35.5 72.5 73.9 230.2 412.1 Total $ 398.3 $ 290.1 $ 85.5 $ 246.5 $ 1,020.4 Contractual Commitments - I&M Less Than 2-3 Years 4-5 Years After Total (in millions) Fuel Purchase Contracts (a) $ 157.7 $ 278.9 $ 189.3 $ 332.7 $ 958.6 Energy and Capacity Purchase Contracts 165.2 196.7 60.9 254.6 677.4 Total $ 322.9 $ 475.6 $ 250.2 $ 587.3 $ 1,636.0 Contractual Commitments - OPCo Less Than 2-3 Years 4-5 Years After Total (in millions) Energy and Capacity Purchase Contracts $ 28.8 $ 58.2 $ 58.1 $ 263.3 $ 408.4 Contractual Commitments - PSO Less Than 2-3 Years 4-5 Years After Total (in millions) Fuel Purchase Contracts (a) $ 25.3 $ 36.2 $ — $ — $ 61.5 Energy and Capacity Purchase Contracts 89.6 77.4 66.8 160.0 393.8 Total $ 114.9 $ 113.6 $ 66.8 $ 160.0 $ 455.3 Contractual Commitments - SWEPCo Less Than 2-3 Years 4-5 Years After Total (in millions) Fuel Purchase Contracts (a) $ 68.5 $ 39.2 $ — $ — $ 107.7 Energy and Capacity Purchase Contracts 8.3 8.4 8.4 4.2 29.3 Total $ 76.8 $ 47.6 $ 8.4 $ 4.2 $ 137.0 (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 $ 179.8 January 2021 to December 2021 AEP Texas 2.2 July 2021

Acquisitions, Dispositions an_2

Acquisitions, Dispositions and Impairments (Tables)	3 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2020
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
Payments for Proceeds from removal costs		2021 2022 (in millions) First Quarter $ 9.6 $ 9.6 Second Quarter 9.6 9.6 Third Quarter 9.6 5.2 Fourth Quarter 9.6 — Total $ 38.4 $ 24.4

Benefit Plans (Tables)

Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2020
Health Care Trend Rates	December 31, Health Care Trend Rates 2020 2019 Initial 6.50 % 6.00 % Ultimate 4.50 % 4.50 % Year Ultimate Reached 2029 2026
Reconciliation of Changes in Benefit Obligations and Fair Value of Assets	AEP Pension Plans OPEB 2020 2019 2020 2019 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 5,236.8 $ 4,810.3 $ 1,225.4 $ 1,194.5 Service Cost 111.9 95.5 10.0 9.5 Interest Cost 167.9 204.4 39.8 50.5 Actuarial Loss 434.7 493.6 39.3 58.8 Plan Amendments — 0.2 (11.4) (11.0) Benefit Payments (406.8) (367.2) (131.0) (113.0) Participant Contributions — — 38.2 35.5 Medicare Subsidy — — 0.6 0.6 Benefit Obligation as of December 31, $ 5,544.5 $ 5,236.8 $ 1,210.9 $ 1,225.4 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 5,015.4 $ 4,695.9 $ 1,781.8 $ 1,534.2 Actual Gain on Plan Assets 832.4 681.1 253.0 321.0 Company Contributions (a) 115.6 5.6 4.7 4.1 Participant Contributions — — 38.2 35.5 Benefit Payments (406.8) (367.2) (131.0) (113.0) Fair Value of Plan Assets as of December 31, $ 5,556.6 $ 5,015.4 $ 1,946.7 $ 1,781.8 Funded (Underfunded) Status as of December 31, $ 12.1 $ (221.4) $ 735.8 $ 556.4 (a) Contributions to the qualified pension plan were $110 million and $0 for the years ended December 31, 2020 and 2019, respectively. Contributions to the non-qualified pension plans were $6 million and $6 million for the years ended December 31, 2020 and 2019, respectively. AEP Texas Pension Plans OPEB 2020 2019 2020 2019 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 441.2 $ 409.3 $ 97.8 $ 95.9 Service Cost 10.0 8.6 0.8 0.8 Interest Cost 13.9 17.5 3.2 4.0 Actuarial Loss 28.1 40.1 2.4 3.9 Plan Amendments — — (1.0) (0.9) Benefit Payments (40.0) (34.3) (10.0) (8.8) Participant Contributions — — 3.1 2.9 Benefit Obligation as of December 31, $ 453.2 $ 441.2 $ 96.3 $ 97.8 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 435.1 $ 410.7 $ 148.1 $ 129.9 Actual Gain on Plan Assets 67.2 58.3 21.1 24.0 Company Contributions 11.7 0.4 — 0.1 Participant Contributions — — 3.1 2.9 Benefit Payments (40.0) (34.3) (10.0) (8.8) Fair Value of Plan Assets as of December 31, $ 474.0 $ 435.1 $ 162.3 $ 148.1 Funded (Underfunded) Status as of December 31, $ 20.8 $ (6.1) $ 66.0 $ 50.3 APCo Pension Plans OPEB 2020 2019 2020 2019 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 647.2 $ 603.1 $ 203.5 $ 205.5 Service Cost 10.5 9.4 1.0 1.0 Interest Cost 20.3 25.2 6.6 8.7 Actuarial Loss 40.0 52.9 5.6 4.7 Plan Amendments — — (1.8) (1.7) Benefit Payments (47.2) (43.4) (23.2) (20.8) Participant Contributions — — 6.3 5.9 Medicare Subsidy — — 0.2 0.2 Benefit Obligation as of December 31, $ 670.8 $ 647.2 $ 198.2 $ 203.5 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 637.0 $ 593.3 $ 271.0 $ 238.4 Actual Gain on Plan Assets 104.5 87.1 36.8 45.3 Company Contributions 7.0 — 2.1 2.2 Participant Contributions — — 6.3 5.9 Benefit Payments (47.2) (43.4) (23.2) (20.8) Fair Value of Plan Assets as of December 31, $ 701.3 $ 637.0 $ 293.0 $ 271.0 Funded (Underfunded) Status as of December 31, $ 30.5 $ (10.2) $ 94.8 $ 67.5 I&M Pension Plans OPEB 2020 2019 2020 2019 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 616.1 $ 567.0 $ 142.9 $ 138.3 Service Cost 15.4 13.4 1.4 1.4 Interest Cost 19.7 23.8 4.7 5.8 Actuarial Loss 44.3 49.8 5.1 8.1 Plan Amendments — — (1.6) (1.5) Benefit Payments (42.2) (37.9) (15.9) (13.6) Participant Contributions — — 4.8 4.4 Benefit Obligation as of December 31, $ 653.3 $ 616.1 $ 141.4 $ 142.9 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 630.5 $ 583.8 $ 216.3 $ 187.3 Actual Gain on Plan Assets 103.3 84.6 33.0 38.2 Company Contributions 6.5 — — — Participant Contributions — — 4.8 4.4 Benefit Payments (42.2) (37.9) (15.9) (13.6) Fair Value of Plan Assets as of December 31, $ 698.1 $ 630.5 $ 238.2 $ 216.3 Funded Status as of December 31, $ 44.8 $ 14.4 $ 96.8 $ 73.4 OPCo Pension Plans OPEB 2020 2019 2020 2019 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 487.8 $ 453.9 $ 130.2 $ 129.5 Service Cost 9.7 7.9 0.9 0.8 Interest Cost 15.4 19.1 4.2 5.5 Actuarial Loss 33.4 40.5 3.1 4.9 Plan Amendments — — (1.3) (1.2) Benefit Payments (36.0) (33.6) (15.0) (13.5) Participant Contributions — — 4.3 4.1 Medicare Subsidy — — — 0.1 Benefit Obligation as of December 31, $ 510.3 $ 487.8 $ 126.4 $ 130.2 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 499.1 $ 466.1 $ 197.1 $ 175.4 Actual Gain on Plan Assets 79.9 66.6 26.6 31.1 Company Contributions 0.1 — — — Participant Contributions — — 4.3 4.1 Benefit Payments (36.0) (33.6) (15.0) (13.5) Fair Value of Plan Assets as of December 31, $ 543.1 $ 499.1 $ 213.0 $ 197.1 Funded Status as of December 31, $ 32.8 $ 11.3 $ 86.6 $ 66.9 PSO Pension Plans OPEB 2020 2019 2020 2019 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 267.5 $ 253.8 $ 64.7 $ 62.3 Service Cost 7.3 6.5 0.7 0.6 Interest Cost 8.5 10.6 2.1 2.6 Actuarial Loss 17.7 16.8 1.9 3.8 Plan Amendments — — (0.7) (0.7) Benefit Payments (21.1) (20.2) (6.8) (5.9) Participant Contributions — — 2.1 2.0 Benefit Obligation as of December 31, $ 279.9 $ 267.5 $ 64.0 $ 64.7 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 276.2 $ 261.2 $ 98.0 $ 84.3 Actual Gain on Plan Assets 44.6 34.7 14.5 17.6 Company Contributions 0.1 0.5 — — Participant Contributions — — 2.1 2.0 Benefit Payments (21.1) (20.2) (6.8) (5.9) Fair Value of Plan Assets as of December 31, $ 299.8 $ 276.2 $ 107.8 $ 98.0 Funded Status as of December 31, $ 19.9 $ 8.7 $ 43.8 $ 33.3 SWEPCo Pension Plans OPEB 2020 2019 2020 2019 Change in Benefit Obligation (in millions) Benefit Obligation as of January 1, $ 314.2 $ 291.4 $ 77.4 $ 72.7 Service Cost 9.9 8.6 0.8 0.8 Interest Cost 10.2 12.4 2.5 3.1 Actuarial Loss 27.4 25.5 2.5 6.0 Plan Amendments — — (0.8) (0.8) Benefit Payments (27.2) (23.7) (7.7) (6.6) Participant Contributions — — 2.4 2.2 Benefit Obligation as of December 31, $ 334.5 $ 314.2 $ 77.1 $ 77.4 Change in Fair Value of Plan Assets Fair Value of Plan Assets as of January 1, $ 296.9 $ 281.0 $ 117.2 $ 98.5 Actual Gain on Plan Assets 48.2 39.5 18.0 23.1 Company Contributions 9.0 0.1 — — Participant Contributions — — 2.4 2.2 Benefit Payments (27.2) (23.7) (7.7) (6.6) Fair Value of Plan Assets as of December 31, $ 326.9 $ 296.9 $ 129.9 $ 117.2 Funded (Underfunded) Status as of December 31, $ (7.6) $ (17.3) $ 52.8 $ 39.8
Benefit Amounts Recognized on the Balance Sheets	Pension Plans OPEB December 31, AEP 2020 2019 2020 2019 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ 93.5 $ — $ 771.9 $ 590.8 Other Current Liabilities – Accrued Short-term Benefit Liability (6.7) (6.1) (2.4) (2.6) Employee Benefits and Pension Obligations – Accrued Long-term Benefit Liability (74.7) (215.3) (33.7) (31.8) Funded (Underfunded) Status $ 12.1 $ (221.4) $ 735.8 $ 556.4 Pension Plans OPEB December 31, AEP Texas 2020 2019 2020 2019 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ 24.7 $ — $ 66.0 $ 50.3 Other Current Liabilities – Accrued Short-term Benefit Liability (0.4) (0.4) — — Deferred Credits and Other Noncurrent Liabilities – Accrued Long-term Benefit Liability (3.5) (5.7) — — Funded (Underfunded) Status $ 20.8 $ (6.1) $ 66.0 $ 50.3 Pension Plans OPEB December 31, APCo 2020 2019 2020 2019 (in millions) Employee Benefits and Pension Assets – Prepaid Benefit Costs $ 31.0 $ — $ 119.1 $ 92.0 Other Current Liabilities – Accrued Short-term Benefit Liability — — (1.8) (2.0) Employee Benefits and Pension Obligations – Accrued Long-term Benefit Liability (0.5) (10.2) (22.5) (22.5) Funded (Underfunded) Status $ 30.5 $ (10.2) $ 94.8 $ 67.5 Pension Plans OPEB December 31, I&M 2020 2019 2020 2019 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ 46.5 $ 15.8 $ 96.8 $ 73.4 Deferred Credits and Other Noncurrent Liabilities – Accrued Long-term Benefit Liability (1.7) (1.4) — — Funded Status $ 44.8 $ 14.4 $ 96.8 $ 73.4 Pension Plans OPEB December 31, OPCo 2020 2019 2020 2019 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ 33.3 $ 11.7 $ 86.6 $ 66.9 Deferred Credits and Other Noncurrent Liabilities – Accrued Long-term Benefit Liability (0.5) (0.4) — — Funded Status $ 32.8 $ 11.3 $ 86.6 $ 66.9 Pension Plans OPEB December 31, PSO 2020 2019 2020 2019 (in millions) Employee Benefits and Pension Assets – Prepaid Benefit Costs $ 21.9 $ 10.6 $ 43.8 $ 33.3 Other Current Liabilities – Accrued Short-term Benefit Liability (0.1) (0.1) — — Deferred Credits and Other Noncurrent Liabilities – Accrued Long-term Benefit Liability (1.9) (1.8) — — Funded Status $ 19.9 $ 8.7 $ 43.8 $ 33.3 Pension Plans OPEB December 31, SWEPCo 2020 2019 2020 2019 (in millions) Deferred Charges and Other Noncurrent Assets – Prepaid Benefit Costs $ — $ — $ 52.8 $ 39.8 Other Current Liabilities – Accrued Short-term Benefit Liability (0.1) (0.1) — — Employee Benefits and Pension Obligations – Accrued Long-term Benefit Liability (7.5) (17.2) — — Funded (Underfunded) Status $ (7.6) $ (17.3) $ 52.8 $ 39.8
Amounts Included in AOCI and Regulatory Assets	AEP Pension Plans OPEB December 31, 2020 2019 2020 2019 Components (in millions) Net Actuarial Loss $ 1,179.6 $ 1,406.2 $ 101.9 $ 225.8 Prior Service Cost (Credit) 0.2 0.2 (227.3) (285.7) Recorded as Regulatory Assets $ 1,182.4 $ 1,351.8 $ (99.0) $ (46.8) Deferred Income Taxes (0.5) 11.5 (5.5) (2.7) Net of Tax AOCI (2.1) 43.1 (20.9) (10.4) AEP Texas Pension Plans OPEB December 31, 2020 2019 2020 2019 Components (in millions) Net Actuarial Loss $ 160.5 $ 184.7 $ 12.3 $ 23.5 Prior Service Credit — — (19.3) (24.2) Recorded as Regulatory Assets $ 151.3 $ 172.2 $ (6.3) $ (0.2) Deferred Income Taxes 2.0 2.7 (0.1) (0.1) Net of Tax AOCI 7.2 9.8 (0.6) (0.4) APCo Pension Plans OPEB December 31, 2020 2019 2020 2019 Components (in millions) Net Actuarial Loss $ 126.3 $ 168.3 $ 11.1 $ 28.8 Prior Service Credit — — (33.2) (41.6) Recorded as Regulatory Assets $ 124.7 $ 166.3 $ (10.3) $ (5.5) Deferred Income Taxes 0.3 0.3 (2.5) (1.5) Net of Tax AOCI 1.3 1.7 (9.3) (5.8) I&M Pension Plans OPEB December 31, 2020 2019 2020 2019 Components (in millions) Net Actuarial Loss $ 39.5 $ 76.0 $ 15.6 $ 32.7 Prior Service Credit — — (31.0) (39.0) Recorded as Regulatory Assets $ 40.3 $ 73.7 $ (14.6) $ (6.2) Deferred Income Taxes (0.1) 0.5 (0.2) — Net of Tax AOCI (0.7) 1.8 (0.6) (0.1) OPCo Pension Plans OPEB December 31, 2020 2019 2020 2019 Components (in millions) Net Actuarial Loss $ 150.0 $ 178.7 $ 3.6 $ 17.2 Prior Service Credit — — (22.9) (28.6) Recorded as Regulatory Assets $ 150.0 $ 178.7 $ (19.3) $ (11.4) PSO Pension Plans OPEB December 31, 2020 2019 2020 2019 Components (in millions) Net Actuarial Loss $ 55.9 $ 73.0 $ 10.5 $ 18.2 Prior Service Credit — — (14.1) (17.8) Recorded as Regulatory Assets $ 55.9 $ 73.0 $ (3.6) $ 0.4 SWEPCo Pension Plans OPEB December 31, 2020 2019 2020 2019 Components (in millions) Net Actuarial Loss $ 86.9 $ 97.8 $ 11.5 $ 21.1 Prior Service Credit — — (17.2) (21.6) Recorded as Regulatory Assets $ 86.9 $ 97.8 $ (3.0) $ — Deferred Income Taxes — — (0.5) — Net of Tax AOCI — — (2.2) (0.5)
Components of Change in Amounts Included in AOCI and Regulatory Assets	AEP Pension Plans OPEB 2020 2019 2020 2019 Components (in millions) Actuarial (Gain) Loss During the Year $ (132.9) $ 108.6 $ (118.0) $ (171.9) Amortization of Actuarial Loss (93.7) (57.6) (5.9) (22.1) Prior Service (Credit) Cost — 0.2 (11.4) (7.6) Amortization of Prior Service Credit — — 69.8 69.1 Change for the Year Ended December 31, $ (226.6) $ 51.2 $ (65.5) $ (132.5) AEP Texas Pension Plans OPEB 2020 2019 2020 2019 Components (in millions) Actuarial (Gain) Loss During the Year $ (16.4) $ 7.6 $ (10.7) $ (12.7) Amortization of Actuarial Loss (7.8) (4.9) (0.5) (1.8) Prior Service Credit — — (1.0) (0.6) Amortization of Prior Service Credit — — 5.9 5.9 Change for the Year Ended December 31, $ (24.2) $ 2.7 $ (6.3) $ (9.2) APCo Pension Plans OPEB 2020 2019 2020 2019 Components (in millions) Actuarial (Gain) Loss During the Year $ (30.8) $ 3.1 $ (16.8) $ (26.4) Amortization of Actuarial Loss (11.2) (7.0) (0.9) (3.7) Prior Service Credit — — (1.8) (1.3) Amortization of Prior Service Credit — — 10.2 10.1 Change for the Year Ended December 31, $ (42.0) $ (3.9) $ (9.3) $ (21.3) I&M Pension Plans OPEB 2020 2019 2020 2019 Components (in millions) Actuarial (Gain) Loss During the Year $ (25.7) $ 2.0 $ (16.4) $ (19.3) Amortization of Actuarial Loss (10.8) (6.6) (0.7) (2.7) Prior Service Credit — — (1.5) (1.0) Amortization of Prior Service Credit — — 9.5 9.4 Change for the Year Ended December 31, $ (36.5) $ (4.6) $ (9.1) $ (13.6) OPCo Pension Plans OPEB 2020 2019 2020 2019 Components (in millions) Actuarial (Gain) Loss During the Year $ (20.2) $ 3.3 $ (12.9) $ (15.8) Amortization of Actuarial Loss (8.5) (5.3) (0.7) (2.5) Prior Service Credit — — (1.3) (0.8) Amortization of Prior Service Credit — — 7.0 6.9 Change for the Year Ended December 31, $ (28.7) $ (2.0) $ (7.9) $ (12.2) PSO Pension Plans OPEB 2020 2019 2020 2019 Components (in millions) Actuarial Gain During the Year $ (12.4) $ (1.7) $ (7.4) $ (8.9) Amortization of Actuarial Loss (4.7) (2.9) (0.3) (1.2) Prior Service Credit — — (0.7) (0.5) Amortization of Prior Service Credit — — 4.4 4.3 Change for the Year Ended December 31, $ (17.1) $ (4.6) $ (4.0) $ (6.3) SWEPCo Pension Plans OPEB 2020 2019 2020 2019 Components (in millions) Actuarial (Gain) Loss During the Year $ (5.2) $ 3.8 $ (9.2) $ (11.4) Amortization of Actuarial Loss (5.7) (3.4) (0.4) (1.4) Prior Service Credit — — (0.8) (0.6) Amortization of Prior Service Credit — — 5.2 5.2 Change for the Year Ended December 31, $ (10.9) $ 0.4 $ (5.2) $ (8.2)
Allocated Assets of Investments	Pension Plan OPEB December 31, Company 2020 2019 2020 2019 AEP Texas 8.5 % 8.7 % 8.3 % 8.3 % APCo 12.6 % 12.7 % 15.1 % 15.2 % I&M 12.6 % 12.6 % 12.2 % 12.1 % OPCo 9.8 % 10.0 % 10.9 % 11.1 % PSO 5.4 % 5.5 % 5.5 % 5.5 % SWEPCo 5.9 % 5.9 % 6.7 % 6.6 %
Accumulated Benefit Obligation	Accumulated Benefit Obligation AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Qualified Pension Plan $ 5,171.3 $ 424.5 $ 645.8 $ 615.8 $ 479.2 $ 258.3 $ 307.1 Nonqualified Pension Plans 72.9 3.6 0.2 0.8 0.2 1.6 1.4 Total as of December 31, 2020 $ 5,244.2 $ 428.1 $ 646.0 $ 616.6 $ 479.4 $ 259.9 $ 308.5 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
Underfunded Projected Benefit Obligation	AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Projected Benefit Obligation $ 81.4 $ 3.9 $ 0.5 $ 1.7 $ 0.6 $ 2.0 $ 334.5 Fair Value of Plan Assets — — — — — — 326.9 Underfunded Projected Benefit Obligation as of December 31, 2020 $ (81.4) $ (3.9) $ (0.5) $ (1.7) $ (0.6) $ (2.0) $ (7.6) 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)
Underfunded Accumulated Benefit Obligation	AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Accumulated Benefit Obligation $ 72.9 $ 3.6 $ 0.2 $ 0.8 $ 0.2 $ 1.6 $ 1.4 Fair Value of Plan Assets — — — — — — — Underfunded Accumulated Benefit Obligation as of December 31, 2020 $ (72.9) $ (3.6) $ (0.2) $ (0.8) $ (0.2) $ (1.6) $ (1.4) 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)
Estimated Contributions and Payments to the Pension and OPEB Plans	Company Pension Plans OPEB (in millions) AEP $ 132.8 $ 3.1 AEP Texas 5.1 0.1 APCo 1.8 1.8 I&M 1.3 — PSO 0.1 — SWEPCo 7.1 —
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) 2021 $ 385.3 $ 36.3 $ 44.7 $ 40.2 $ 35.4 $ 21.8 $ 25.2 2022 382.8 35.9 45.1 42.4 36.0 21.2 25.4 2023 384.3 36.1 45.1 41.5 34.2 22.3 25.7 2024 384.0 35.9 45.7 42.7 34.0 21.9 25.7 2025 377.1 35.2 44.0 42.7 33.3 21.1 25.3 Years 2026 to 2030, in Total 1,763.1 154.1 209.7 205.2 155.0 94.8 115.7 OPEB Benefit Payments AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) 2021 $ 121.6 $ 9.5 $ 21.1 $ 15.1 $ 13.7 $ 6.4 $ 7.5 2022 122.5 9.9 20.8 15.3 13.9 6.7 7.8 2023 117.4 9.7 19.8 14.7 13.2 6.6 7.6 2024 121.9 10.3 20.5 15.3 13.7 6.9 8.2 2025 120.9 10.4 20.0 15.1 13.4 6.9 8.2 Years 2026 to 2030, in Total 573.9 48.6 93.3 70.9 61.7 32.1 39.1 OPEB Medicare AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) 2021 $ 0.2 $ — $ 0.1 $ — $ — $ — $ — 2022 0.2 — 0.1 — — — — 2023 0.3 — 0.1 — — — — 2024 0.3 — 0.1 — — — — 2025 0.3 — 0.1 — — — — Years 2026 to 2030, in Total 1.5 — 0.6 — — — —
Components of Net Periodic Benefit Cost	AEP Pension Plans OPEB Years Ended December 31, 2020 2019 2018 2020 2019 2018 (in millions) Service Cost $ 111.9 $ 95.5 $ 97.6 $ 10.0 $ 9.5 $ 11.6 Interest Cost 167.9 204.4 187.8 39.8 50.5 47.4 Expected Return on Plan Assets (264.9) (296.0) (290.3) (95.6) (93.7) (102.2) Amortization of Prior Service Credit — — — (69.8) (69.1) (69.1) Amortization of Net Actuarial Loss 93.7 57.6 85.2 5.9 22.1 10.5 Settlements — — 2.6 — — — Net Periodic Benefit Cost (Credit) 108.6 61.5 82.9 (109.7) (80.7) (101.8) Capitalized Portion (47.0) (38.6) (41.1) (4.2) (3.8) (4.9) Net Periodic Benefit Cost (Credit) Recognized in Expense $ 61.6 $ 22.9 $ 41.8 $ (113.9) $ (84.5) $ (106.7) AEP Texas Pension Plans OPEB Years Ended December 31, 2020 2019 2018 2020 2019 2018 (in millions) Service Cost $ 10.0 $ 8.6 $ 9.2 $ 0.8 $ 0.8 $ 0.9 Interest Cost 13.9 17.5 16.0 3.2 4.0 3.8 Expected Return on Plan Assets (22.7) (25.8) (25.6) (8.0) (7.8) (8.6) Amortization of Prior Service Credit — — — (5.9) (5.9) (5.9) Amortization of Net Actuarial Loss 7.8 4.9 7.2 0.5 1.8 0.8 Net Periodic Benefit Cost (Credit) 9.0 5.2 6.8 (9.4) (7.1) (9.0) Capitalized Portion (5.5) (4.5) (4.8) (0.4) (0.4) (0.5) Net Periodic Benefit Cost (Credit) Recognized in Expense $ 3.5 $ 0.7 $ 2.0 $ (9.8) $ (7.5) $ (9.5) APCo Pension Plans OPEB Years Ended December 31, 2020 2019 2018 2020 2019 2018 (in millions) Service Cost $ 10.5 $ 9.4 $ 9.3 $ 1.0 $ 1.0 $ 1.1 Interest Cost 20.3 25.2 23.5 6.6 8.7 8.2 Expected Return on Plan Assets (33.6) (37.4) (36.6) (14.4) (14.6) (16.0) Amortization of Prior Service Credit — — — (10.2) (10.1) (10.0) Amortization of Net Actuarial Loss 11.2 7.0 10.6 0.9 3.7 1.9 Net Periodic Benefit Cost (Credit) 8.4 4.2 6.8 (16.1) (11.3) (14.8) Capitalized Portion (4.5) (4.0) (3.8) (0.4) (0.4) (0.5) Net Periodic Benefit Cost (Credit) Recognized in Expense $ 3.9 $ 0.2 $ 3.0 $ (16.5) $ (11.7) $ (15.3) I&M Pension Plans OPEB Years Ended December 31, 2020 2019 2018 2020 2019 2018 (in millions) Service Cost $ 15.4 $ 13.4 $ 13.6 $ 1.4 $ 1.4 $ 1.6 Interest Cost 19.7 23.8 22.1 4.7 5.8 5.4 Expected Return on Plan Assets (33.3) (36.8) (35.7) (11.7) (11.4) (12.3) Amortization of Prior Service Credit — — — (9.5) (9.4) (9.5) Amortization of Net Actuarial Loss 10.8 6.6 9.8 0.7 2.7 1.2 Net Periodic Benefit Cost (Credit) 12.6 7.0 9.8 (14.4) (10.9) (13.6) Capitalized Portion (4.3) (3.4) (5.6) (0.4) (0.4) (0.7) Net Periodic Benefit Cost (Credit) Recognized in Expense $ 8.3 $ 3.6 $ 4.2 $ (14.8) $ (11.3) $ (14.3) OPCo Pension Plans OPEB Years Ended December 31, 2020 2019 2018 2020 2019 2018 (in millions) Service Cost $ 9.7 $ 7.9 $ 7.7 $ 0.9 $ 0.8 $ 0.9 Interest Cost 15.4 19.1 17.7 4.2 5.5 5.1 Expected Return on Plan Assets (26.3) (29.3) (28.8) (10.5) (10.8) (11.7) Amortization of Prior Service Credit — — — (7.0) (6.9) (6.9) Amortization of Net Actuarial Loss 8.5 5.3 8.0 0.7 2.5 1.1 Net Periodic Benefit Cost (Credit) 7.3 3.0 4.6 (11.7) (8.9) (11.5) Capitalized Portion (5.0) (3.7) (3.6) (0.5) (0.4) (0.4) Net Periodic Benefit Cost (Credit) Recognized in Expense $ 2.3 $ (0.7) $ 1.0 $ (12.2) $ (9.3) $ (11.9) PSO Pension Plans OPEB Years Ended December 31, 2020 2019 2018 2020 2019 2018 (in millions) Service Cost $ 7.3 $ 6.5 $ 7.0 $ 0.7 $ 0.6 $ 0.7 Interest Cost 8.5 10.6 9.9 2.1 2.6 2.5 Expected Return on Plan Assets (14.5) (16.3) (16.1) (5.2) (5.1) (5.6) Amortization of Prior Service Credit — — — (4.4) (4.3) (4.3) Amortization of Net Actuarial Loss 4.7 2.9 4.4 0.3 1.2 0.5 Net Periodic Benefit Cost (Credit) 6.0 3.7 5.2 (6.5) (5.0) (6.2) Capitalized Portion (2.8) (2.4) (2.6) (0.3) (0.2) (0.3) Net Periodic Benefit Cost (Credit) Recognized in Expense $ 3.2 $ 1.3 $ 2.6 $ (6.8) $ (5.2) $ (6.5) SWEPCo Pension Plans OPEB Years Ended December 31, 2020 2019 2018 2020 2019 2018 (in millions) Service Cost $ 9.9 $ 8.6 $ 9.3 $ 0.8 $ 0.8 $ 0.9 Interest Cost 10.2 12.4 11.3 2.5 3.1 2.8 Expected Return on Plan Assets (15.7) (17.7) (17.3) (6.3) (5.9) (6.4) Amortization of Prior Service Credit — — — (5.2) (5.2) (5.2) Amortization of Net Actuarial Loss 5.7 3.4 5.1 0.4 1.4 0.6 Settlements — — 0.4 — — — Net Periodic Benefit Cost (Credit) 10.1 6.7 8.8 (7.8) (5.8) (7.3) Capitalized Portion (3.4) (2.9) (3.1) (0.3) (0.3) (0.3) Net Periodic Benefit Cost (Credit) Recognized in Expense $ 6.7 $ 3.8 $ 5.7 $ (8.1) $ (6.1) $ (7.6)
Cost for Matching Contributions to the Retirement Savings Plans	Year Ended December 31, Company 2020 2019 2018 (in millions) AEP $ 81.8 $ 76.4 $ 71.8 AEP Texas 6.4 5.9 5.7 APCo 7.7 7.5 7.5 I&M 11.3 11.0 10.5 OPCo 7.3 6.6 6.3 PSO 4.9 4.6 4.5 SWEPCo 6.7 6.2 5.9
Benefit Obligations [Member]
Actuarial Assumptions	Pension Plans OPEB December 31, Assumption 2020 2019 2020 2019 Discount Rate 2.50 % 3.25 % 2.55 % 3.30 % Interest Crediting Rate 4.00 % 4.00 % NA NA NA Not applicable. Pension Plans December 31, Assumption – Rate of Compensation Increase (a) 2020 2019 AEP 5.00 % 4.95 % AEP Texas 5.05 % 5.00 % APCo 4.85 % 4.80 % I&M 5.00 % 4.95 % OPCo 5.25 % 5.15 % PSO 5.05 % 5.05 % SWEPCo 4.90 % 4.90 % (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 2020 2019 2018 2020 2019 2018 Discount Rate 3.25 % 4.30 % 3.65 % 3.30 % 4.30 % 3.60 % Interest Crediting Rate 4.00 % 4.00 % 4.00 % NA NA NA Expected Return on Plan Assets 5.75 % 6.25 % 6.00 % 5.50 % 6.25 % 6.00 % NA Not applicable. Pension Plans Year Ended December 31, Assumption – Rate of Compensation Increase (a) 2020 2019 2018 AEP 5.00 % 4.95 % 4.85 % AEP Texas 5.05 % 5.00 % 4.95 % APCo 4.85 % 4.75 % 4.75 % I&M 5.00 % 4.95 % 4.90 % OPCo 5.25 % 5.20 % 5.00 % PSO 5.05 % 5.05 % 4.90 % SWEPCo 4.90 % 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.
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 $ 542.3 $ — $ — $ — $ 542.3 9.7 % International 676.3 — — — 676.3 12.2 % Common Collective Trusts (c) — — — 650.0 650.0 11.7 % Subtotal – Equities 1,218.6 — — 650.0 1,868.6 33.6 % Fixed Income (a): United States Government and Agency Securities (1.4) 1,134.1 — — 1,132.7 20.4 % Corporate Debt — 1,425.0 — — 1,425.0 25.6 % Foreign Debt — 214.0 — — 214.0 3.9 % State and Local Government — 56.0 — — 56.0 1.0 % Other – Asset Backed — 0.8 — — 0.8 — % Subtotal – Fixed Income (1.4) 2,829.9 — — 2,828.5 50.9 % Infrastructure (c) — — — 91.1 91.1 1.6 % Real Estate (c) — — — 231.6 231.6 4.2 % Alternative Investments (c) — — — 431.8 431.8 7.8 % Cash and Cash Equivalents (c) — 49.3 — 58.2 107.5 1.9 % Other – Pending Transactions and Accrued Income (b) — — — (2.5) (2.5) — % Total $ 1,217.2 $ 2,879.2 $ — $ 1,460.2 $ 5,556.6 100.0 % (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 (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 (in millions) Equities: Domestic $ 399.9 $ — $ — $ — $ 399.9 20.6 % International 290.7 — — — 290.7 14.9 % Common Collective Trusts (b) — — — 264.7 264.7 13.6 % Subtotal – Equities 690.6 — — 264.7 955.3 49.1 % Fixed Income: Common Collective Trust – Debt (b) — — — 186.4 186.4 9.6 % United States Government and Agency Securities (0.2) 199.7 — — 199.5 10.2 % Corporate Debt — 248.7 — — 248.7 12.8 % Foreign Debt — 34.9 — — 34.9 1.8 % State and Local Government 73.9 13.1 — — 87.0 4.5 % Subtotal – Fixed Income 73.7 496.4 — 186.4 756.5 38.9 % Trust Owned Life Insurance: International Equities — 64.8 — — 64.8 3.3 % United States Bonds — 135.9 — — 135.9 7.0 % Subtotal – Trust Owned Life Insurance — 200.7 — — 200.7 10.3 % Cash and Cash Equivalents (b) 26.3 — — 5.7 32.0 1.6 % Other – Pending Transactions and Accrued Income (a) — — — 2.2 2.2 0.1 % Total $ 790.6 $ 697.1 $ — $ 459.0 $ 1,946.7 100.0 % (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 $ 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.

Business Segments (Tables)

Business Segments (Tables)	12 Months Ended
	Dec. 31, 2020
Reportable Segment Information	Vertically Integrated Utilities Transmission and Distribution Utilities AEP Transmission Holdco Generation & Marketing Corporate and Other (a) Reconciling Adjustments Consolidated (in millions) 2020 Revenues from: External Customers $ 8,753.2 $ 4,238.7 $ 297.4 $ 1,621.0 $ 8.2 $ — $ 14,918.5 Other Operating Segments 126.2 107.2 901.4 104.6 88.6 (1,328.0) — Total Revenues $ 8,879.4 $ 4,345.9 $ 1,198.8 $ 1,725.6 $ 96.8 $ (1,328.0) $ 14,918.5 Depreciation and Amortization $ 1,600.5 $ 751.1 $ 257.6 $ 72.8 $ 0.8 $ — $ 2,682.8 Interest Expense 565.0 289.2 133.2 24.0 196.4 (42.1) 1,165.7 Income Tax Expense (Benefit) (7.0) 29.7 130.8 (108.0) (5.0) — 40.5 Equity Earnings of Unconsolidated Subsidiaries 2.9 — 82.4 3.2 2.6 — 91.1 Net Income (Loss) $ 1,064.5 $ 496.4 $ 508.5 $ 216.9 $ (89.6) $ — $ 2,196.7 Gross Property Additions $ 2,291.2 $ 2,108.1 $ 1,649.3 $ 197.0 $ 16.0 $ (15.3) $ 6,246.3 Total Property, Plant and Equipment $ 49,023.3 $ 21,145.0 $ 11,827.2 $ 1,910.2 $ 407.3 $ — $ 84,313.0 Accumulated Depreciation and Amortization 15,586.2 3,879.3 595.7 166.1 184.1 — 20,411.4 Total Property, Plant and Equipment – Net $ 33,437.1 $ 17,265.7 $ 11,231.5 $ 1,744.1 $ 223.2 $ — $ 63,901.6 Total Assets $ 42,752.7 $ 19,765.9 $ 12,627.3 $ 3,585.9 $ 5,987.1 (b) $ (3,961.7) (c) $ 80,757.2 Investments in Equity Method Investees $ 37.1 $ 2.1 $ 831.3 $ 467.0 $ 68.8 $ — $ 1,406.3 Long-term Debt Due Within One Year: Nonaffiliated $ 1,034.6 $ 588.8 $ 52.3 $ — $ 410.4 (d) $ — $ 2,086.1 Long-term Debt: Affiliated 65.0 — — — — (65.0) — Nonaffiliated 12,375.6 6,661.9 4,075.7 — 5,873.2 (d) — 28,986.4 Total Long-term Debt $ 13,475.2 $ 7,250.7 $ 4,128.0 $ — $ 6,283.6 $ (65.0) $ 31,072.5 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 (e) 2,514.5 Interest Expense 568.3 243.3 103.3 30.0 193.7 (66.1) (e) 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) (e) $ 79,145.7 Accumulated Depreciation and Amortization 14,580.4 3,911.2 418.9 99.0 184.5 (186.4) (e) 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) (e) $ 60,138.1 Total Assets $ 41,228.8 $ 18,757.5 $ 11,143.5 $ 3,123.8 $ 5,440.0 (b) $ (3,801.3) (c)(e) $ 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 (d) — 1,598.7 Long-term Debt: Affiliated 39.0 — — — — (39.0) — Nonaffiliated 12,162.0 6,248.1 3,593.8 — 3,122.9 — 25,126.8 Total Long-term Debt $ 12,925.7 $ 6,640.3 $ 3,593.8 $ — $ 3,624.7 (d) $ (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 (e) 2,286.6 Interest Expense 567.8 248.1 90.7 14.9 122.6 (59.7) (e) 984.4 Income Tax Expense 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 Assets $ 38,874.3 $ 17,083.4 $ 9,543.7 $ 1,979.7 $ 4,036.5 (b) $ (2,714.8) (c)(e) $ 68,802.8 (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 elimination of AEP Parent’s investments in wholly-owned subsidiary companies. (c) Reconciling Adjustments for Total Assets primarily include elimination of intercompany advances to affiliates and intercompany accounts receivable. (d) Amounts reflect the impact of fair value hedge accounting. See “Accounting for Fair Value Hedging Strategies” section of Note 10 for additional information. (e) Includes eliminations due to an intercompany finance lease. State Transcos AEPTCo Parent Reconciling Adjustments AEPTCo 2020 (in millions) Revenues from: External Customers $ 248.8 $ — $ — $ 248.8 Sales to AEP Affiliates 896.3 — — 896.3 Other Revenues 0.6 — — 0.6 Total Revenues $ 1,145.7 $ — $ — $ 1,145.7 Depreciation and Amortization $ 249.0 $ — $ — $ 249.0 Interest Income 0.9 149.6 (148.1) (a) 2.4 Allowance for Equity Funds Used During Construction 74.0 — — 74.0 Interest Expense 127.8 148.1 (148.1) (a) 127.8 Income Tax Expense 106.5 0.2 — 106.7 Net Income $ 422.3 $ 1.1 (b) $ — $ 423.4 Gross Property Additions $ 1,621.9 $ — $ — $ 1,621.9 Total Transmission Property $ 11,345.6 $ — $ — $ 11,345.6 Accumulated Depreciation and Amortization 572.8 — — 572.8 Total Transmission Property - Net $ 10,772.8 $ — $ — $ 10,772.8 Notes Receivable - Affiliated $ — $ 3,948.5 $ (3,948.5) (c) $ — Total Assets $ 11,185.1 $ 4,084.0 (d) $ (4,023.1) (e) $ 11,246.0 Total Long-Term Debt $ 3,990.0 $ 3,948.5 $ (3,990.0) (c) $ 3,948.5 State Transcos AEPTCo Parent Reconciling Adjustments AEPTCo 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 2018 (in millions) Revenues from: External Customers $ 177.0 $ — $ — $ 177.0 Sales to AEP Affiliates 598.9 — — 598.9 Other 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 Assets $ 8,406.8 $ 2,857.1 (d) $ (2,869.8) (e) $ 8,394.1 (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 (Tables

Derivatives and Hedging (Tables)	12 Months Ended
	Dec. 31, 2020
Notional Volume of Derivative Instruments	December 31, 2020 Primary Risk Unit of AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Commodity: Power MWhs 331.3 — 46.9 19.7 3.0 11.9 4.0 Natural Gas MMBtus 26.9 — — — — — 7.9 Heating Oil and Gasoline Gallons 6.9 1.8 1.1 0.6 1.4 0.7 0.9 Interest Rate USD $ 129.8 $ — $ — $ — $ — $ — $ — Interest Rate on Long-term Debt USD $ 1,150.0 $ — $ 200.0 $ — $ — $ — $ — December 31, 2019 Primary Risk Unit of 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 $ — $ — $ — $ — $ — $ —
Fair Value of Derivative Instruments	AEP December 31, 2020 Risk Hedging Contracts Gross Amounts Gross Net Amounts of Balance Sheet Location Commodity (a) Commodity (a) Interest Rate (a) (in millions) Current Risk Management Assets $ 239.1 $ 21.1 $ 5.0 $ 265.2 $ (170.5) $ 94.7 Long-term Risk Management Assets 275.9 18.0 — 293.9 (51.7) 242.2 Total Assets 515.0 39.1 5.0 559.1 (222.2) 336.9 Current Risk Management Liabilities 193.0 54.4 3.4 250.8 (172.0) 78.8 Long-term Risk Management Liabilities 222.2 60.1 4.1 286.4 (53.6) 232.8 Total Liabilities 415.2 114.5 7.5 537.2 (225.6) 311.6 Total MTM Derivative Contract Net Assets (Liabilities) $ 99.8 $ (75.4) $ (2.5) $ 21.9 $ 3.4 $ 25.3 December 31, 2019 Risk Hedging Contracts Gross Amounts Gross Net Amounts of 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 AEP Texas December 31, 2020 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 $ 0.4 $ (0.4) $ — Long-term Risk Management Assets — — — Total Assets 0.4 (0.4) — Current Risk Management Liabilities — — — Long-term Risk Management Liabilities — — — Total Liabilities — — — Total MTM Derivative Net Assets (Liabilities) $ 0.4 $ (0.4) $ — 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 $ — $ — $ — APCo December 31, 2020 Risk Gross Amounts of Risk Gross Amounts Net Amounts of Assets/ Management Hedging Management Offset in the Liabilities Presented in Contracts - Contracts - Assets/Liabilities Statement of the Statement of Balance Sheet Location Commodity (a) Interest Rate (a) Recognized Financial Position (b) Financial Position (c) (in millions) Current Risk Management Assets $ 38.8 $ 2.4 $ 41.2 $ (18.8) $ 22.4 Deferred Charges and Other Noncurrent Assets - Long-term Risk Management Assets 0.7 — 0.7 (0.6) 0.1 Total Assets 39.5 2.4 41.9 (19.4) 22.5 Current Risk Management Liabilities 19.7 3.4 23.1 (18.5) 4.6 Deferred Credits and Other Noncurrent Liabilities - Long-term Risk Management Liabilities 0.6 — 0.6 (0.5) 0.1 Total Liabilities 20.3 3.4 23.7 (19.0) 4.7 Total MTM Derivative Contract Net Assets (Liabilities) $ 19.2 $ (1.0) $ 18.2 $ (0.4) $ 17.8 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 Deferred Charges and Other Noncurrent Assets - 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 Deferred Credits and Other Noncurrent Liabilities - 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 I&M December 31, 2020 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 $ 17.2 $ (13.6) $ 3.6 Deferred Charges and Other Noncurrent Assets - Long-term Risk Management Assets 0.5 (0.4) 0.1 Total Assets 17.7 (14.0) 3.7 Other Current Liabilities - Current Risk Management Liabilities 12.1 (12.0) 0.1 Deferred Credits and Other Noncurrent Liabilities - Long-term Risk Management Liabilities 0.4 (0.3) 0.1 Total Liabilities 12.5 (12.3) 0.2 Total MTM Derivative Contract Net Assets (Liabilities) $ 5.2 $ (1.7) $ 3.5 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 Deferred Charges and Other Noncurrent Assets - Long-term Risk Management Assets 0.5 (0.4) 0.1 Total Assets 67.4 (57.5) 9.9 Other Current Liabilities - Current Risk Management Liabilities 55.2 (54.7) 0.5 Deferred Credits and Other Noncurrent Liabilities - 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 OPCo December 31, 2020 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 $ 0.3 $ (0.3) $ — Long-term Risk Management Assets — — — Total Assets 0.3 (0.3) — Current Risk Management Liabilities 8.7 — 8.7 Long-term Risk Management Liabilities 101.6 — 101.6 Total Liabilities 110.3 — 110.3 Total MTM Derivative Contract Net Liabilities $ (110.0) $ (0.3) $ (110.3) 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) PSO December 31, 2020 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 $ 10.5 $ (0.2) $ 10.3 Long-term Risk Management Assets — — — Total Assets 10.5 (0.2) 10.3 Current Risk Management Liabilities — — — Long-term Risk Management Liabilities — — — Total Liabilities — — — Total MTM Derivative Net Assets (Liabilities) $ 10.5 $ (0.2) $ 10.3 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 SWEPCo December 31, 2020 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 $ 3.4 $ (0.2) $ 3.2 Long-term Risk Management Assets — — — Total Assets 3.4 (0.2) 3.2 Current Risk Management Liabilities 0.7 — 0.7 Long-term Risk Management Liabilities 1.0 — 1.0 Total Liabilities 1.7 — 1.7 Total MTM Derivative Net Assets (Liabilities) $ 1.7 $ (0.2) $ 1.5 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 (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	Year Ended December 31, 2020 Location of Gain (Loss) AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Vertically Integrated Utilities Revenues $ 0.8 $ — $ — $ — $ — $ — $ — Generation & Marketing Revenues 9.5 — — — — — — Electric Generation, Transmission and Distribution Revenues — — 0.4 0.1 — — 0.1 Purchased Electricity for Resale 1.4 — 1.2 0.1 — — — Other Operation (2.0) (0.6) (0.2) (0.2) (0.3) (0.2) (0.3) Maintenance (2.9) (0.8) (0.4) (0.3) (0.5) (0.3) (0.4) Regulatory Assets (a) (4.8) — — (0.1) (6.6) — 1.4 Regulatory Liabilities (a) 114.9 0.4 20.3 12.4 12.4 39.1 20.2 Total Gain (Loss) on Risk Management Contracts $ 116.9 $ (1.0) $ 21.3 $ 12.0 $ 5.0 $ 38.6 $ 21.0 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 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 (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, 2020 December 31, 2019 December 31, 2020 December 31, 2019 (in millions) Long-term Debt (a) (b) $ (995.9) $ (510.8) $ (51.7) $ (14.5) (a) Amounts included on the balance sheets within Long-term Debt Due within One Year and Long-term Debt, respectively. (b) Amounts include $(53) million and $0 as of December 31, 2020 and 2019, respectively, for the fair value hedge adjustment of hedged debt obligations for which hedge accounting has been discontinued.
Gain (Loss) on Hedging Instruments	Years Ended December 31, 2020 2019 2018 (in millions) Gain (Loss) on Interest Rate Contracts: Fair Value Hedging Instruments (a) $ 41.1 $ 31.9 $ (11.3) Fair Value Portion of Long-term Debt (a) (41.1) (31.9) 11.3 (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 AEP’s Balance Sheets December 31, 2020 December 31, 2019 Commodity Interest Rate Commodity Interest Rate (in millions) AOCI Gain (Loss) Net of Tax $ (60.6) $ (47.5) $ (103.5) $ (11.5) Portion Expected to be Reclassed to Net Income During the Next Twelve Months (27.1) (5.7) (51.7) (2.1) Impact of Cash Flow Hedges on the Registrant Subsidiaries’ Balance Sheets December 31, 2020 December 31, 2019 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 $ (2.3) $ (1.1) $ (3.4) $ (1.1) APCo (0.8) 0.4 0.9 0.9 I&M (8.3) (1.6) (9.9) (1.6) PSO 0.1 0.1 1.1 1.0 SWEPCo (0.3) (1.5) (1.8) (1.5)
Liabilities Subject to Cross Default Provisions	December 31, 2020 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 $ 188.4 $ — $ 169.2 APCo 4.3 — 3.5 I&M 0.5 — 0.1 SWEPCo 1.8 — 1.8 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

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2020
Book Values and Fair Values of Long-term Debt	December 31, 2020 2019 Company Book Value Fair Value Book Value Fair Value (in millions) AEP (a) $ 31,072.5 $ 37,457.0 $ 26,725.5 $ 30,172.0 AEP Texas 4,820.4 5,682.6 4,558.4 4,981.5 AEPTCo 3,948.5 4,984.3 3,427.3 3,868.0 APCo 4,834.1 6,391.8 4,363.8 5,253.1 I&M 3,029.9 3,775.3 3,050.2 3,453.8 OPCo 2,430.2 3,154.9 2,082.0 2,554.3 PSO 1,373.8 1,732.1 1,386.2 1,603.3 SWEPCo 2,636.4 3,210.1 2,655.6 2,927.9 (a) The fair value amounts include debt related to AEP’s Equity Units and had a fair value of $1.7 billion and $871 million as of December 31, 2020 and 2019, respectively. See “Equity Units” section of Note 14 for additional information.
Other Temporary Investments	December 31, 2020 Gross Gross Unrealized Unrealized Fair Other Temporary Investments Cost Gains Losses Value (in millions) Restricted Cash and Other Cash Deposits (a) $ 68.3 $ — $ — $ 68.3 Fixed Income Securities – Mutual Funds (b) 120.7 2.8 — 123.5 Equity Securities – Mutual Funds 25.9 28.7 — 54.6 Total Other Temporary Investments $ 214.9 $ 31.5 $ — $ 246.4 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 (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, 2020 2019 2018 (in millions) Proceeds from Investment Sales $ 50.9 $ 21.2 $ — Purchases of Investments 41.6 45.0 3.1 Gross Realized Gains on Investment Sales 3.8 — — Gross Realized Losses on Investment Sales 0.2 0.4 —
Nuclear Trust Fund Investments	December 31, 2020 2019 Gross Other-Than- Gross Other-Than- Fair Unrealized Temporary Fair Unrealized Temporary Value Gains Impairments Value Gains Impairments (in millions) Cash and Cash Equivalents $ 25.8 $ — $ — $ 15.3 $ — $ — Fixed Income Securities: United States Government 1,025.6 98.5 (7.1) 1,112.5 55.5 (6.1) Corporate Debt 86.3 9.6 (1.7) 72.4 5.3 (1.6) State and Local Government 114.3 0.9 (0.4) 7.6 0.7 (0.2) Subtotal Fixed Income Securities 1,226.2 109.0 (9.2) 1,192.5 61.5 (7.9) Equity Securities - Domestic (a) 2,054.7 1,400.8 — 1,767.9 1,144.4 — Spent Nuclear Fuel and Decommissioning Trusts $ 3,306.7 $ 1,509.8 $ (9.2) $ 2,975.7 $ 1,205.9 $ (7.9) (a) Amount reported as Gross Unrealized Gains includes unrealized gains of $1.4 billion and $1.1 billion and unrealized losses of $9 million and $5 million as of December 31, 2020 and 2019, respectively.
Securities Activity Within the Decommissioning and SNF Trusts	Years Ended December 31, 2020 2019 2018 (in millions) Proceeds from Investment Sales $ 1,593.4 $ 1,473.0 $ 2,010.0 Purchases of Investments 1,637.2 1,531.0 2,064.7 Gross Realized Gains on Investment Sales 26.4 76.5 47.5 Gross Realized Losses on Investment Sales 26.1 24.3 32.8
Contractual Maturities, Fair Value of Debt Securities	Fair Value of Fixed Income Securities (in millions) Within 1 year $ 294.8 After 1 year through 5 years 371.3 After 5 years through 10 years 214.4 After 10 years 345.7 Total $ 1,226.2
Fair Value, Assets and Liabilities Measured on Recurring Basis	AEP December 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Other Temporary Investments Restricted Cash and Other Cash Deposits (a) $ 57.8 $ — $ — $ 10.5 $ 68.3 Fixed Income Securities – Mutual Funds 123.5 — — — 123.5 Equity Securities – Mutual Funds (b) 54.6 — — — 54.6 Total Other Temporary Investments 235.9 — — 10.5 246.4 Risk Management Assets Risk Management Commodity Contracts (c) (d) 0.9 258.8 252.4 (190.0) 322.1 Cash Flow Hedges: Commodity Hedges (c) — 34.4 3.9 (28.5) 9.8 Interest Rate Hedges — 2.4 — — 2.4 Fair Value Hedges — 2.6 — — 2.6 Total Risk Management Assets 0.9 298.2 256.3 (218.5) 336.9 Spent Nuclear Fuel and Decommissioning Trusts Cash and Cash Equivalents (e) 16.8 — — 9.0 25.8 Fixed Income Securities: United States Government — 1,025.6 — — 1,025.6 Corporate Debt — 86.3 — — 86.3 State and Local Government — 114.3 — — 114.3 Subtotal Fixed Income Securities — 1,226.2 — — 1,226.2 Equity Securities – Domestic (b) 2,054.7 — — — 2,054.7 Total Spent Nuclear Fuel and Decommissioning Trusts 2,071.5 1,226.2 — 9.0 3,306.7 Other Investments (h) — — 31.8 — 31.8 Total Assets $ 2,308.3 $ 1,524.4 $ 288.1 $ (199.0) $ 3,921.8 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (d) $ 0.9 $ 244.2 $ 167.2 $ (193.4) $ 218.9 Cash Flow Hedges: Commodity Hedges (c) — 106.1 7.6 (28.5) 85.2 Interest Rate Hedges — 3.4 — — 3.4 Fair Value Hedges — 4.1 — — 4.1 Total Risk Management Liabilities $ 0.9 $ 357.8 $ 174.8 $ (221.9) $ 311.6 AEP 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) (f) 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) (f) $ 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 Texas December 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 28.7 $ — $ — $ — $ 28.7 Risk Management Assets Risk Management Commodity Contracts (c) — 0.4 — (0.4) — Total Assets $ 28.7 $ 0.4 $ — $ (0.4) $ 28.7 December 31, 2019 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 154.7 $ — $ — $ — $ 154.7 APCo December 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 16.9 $ — $ — $ — $ 16.9 Risk Management Assets Risk Management Commodity Contracts (c) (g) — 19.4 19.9 (19.2) 20.1 Cash Flow Hedges: Interest Rate Hedges — 2.4 — — 2.4 Total Risk Management Assets — 21.8 19.9 (19.2) 22.5 Total Assets $ 16.9 $ 21.8 $ 19.9 $ (19.2) $ 39.4 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 19.5 $ 0.6 $ (18.8) $ 1.3 Cash Flow Hedges: Interest Rate Hedges — 3.4 — — 3.4 Total Risk Management Liabilities $ — $ 22.9 $ 0.6 $ (18.8) $ 4.7 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 I&M December 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ 15.1 $ 2.5 $ (13.9) $ 3.7 Spent Nuclear Fuel and Decommissioning Trusts Cash and Cash Equivalents (e) 16.8 — — 9.0 25.8 Fixed Income Securities: United States Government — 1,025.6 — — 1,025.6 Corporate Debt — 86.3 — — 86.3 State and Local Government — 114.3 — — 114.3 Subtotal Fixed Income Securities — 1,226.2 — — 1,226.2 Equity Securities - Domestic (b) 2,054.7 — — — 2,054.7 Total Spent Nuclear Fuel and Decommissioning Trusts 2,071.5 1,226.2 — 9.0 3,306.7 Total Assets $ 2,071.5 $ 1,241.3 $ 2.5 $ (4.9) $ 3,310.4 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 12.0 $ 0.4 $ (12.2) $ 0.2 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 OPCo December 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ 0.3 $ — $ (0.3) $ — Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ — $ 110.3 $ — $ 110.3 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 PSO December 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ 0.2 $ 10.3 $ (0.2) $ 10.3 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) $ — SWEPCo December 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ 0.1 $ 3.3 $ (0.2) $ 3.2 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ — $ 1.7 $ — $ 1.7 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 (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, 2020 maturities of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), were as follows: Level 2 matures $3 million in periods 2022-2024, $11 million in periods 2025-2026 and $1 million in periods 2027-2033; Level 3 matures $47 million in 2021, $37 million in periods 2022-2024, $14 million in periods 2025-2026 and $(13) million in periods 2027-2033. 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, 2019 maturities of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), were 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. (g) Substantially comprised of power contracts for the Registrant Subsidiaries. (h) See “Warrants Held in Investee” section of Note 10 for additional information.
Changes in Fair Value of Net Trading Derivatives Classified as Level 3	Year Ended December 31, 2020 AEP APCo I&M OPCo PSO SWEPCo (in millions) Balance as of December 31, 2019 $ 109.9 $ 37.7 $ 5.8 $ (103.6) $ 15.8 $ 1.4 Realized Gain (Loss) Included in Net Income (or Changes in Net Assets) (a) (b) 39.5 13.2 2.5 (1.6) 11.9 2.8 Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date (a) 35.3 — — — — — Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income (c) 13.8 — — — — — Settlements (113.1) (51.6) (8.6) 8.9 (27.6) (6.6) Transfers into Level 3 (d) (e) (3.8) — — — — — Transfers out of Level 3 (e) 5.6 0.7 0.4 — — — Changes in Fair Value Allocated to Regulated Jurisdictions (f) 26.1 19.3 2.0 (14.0) 10.2 4.0 Balance as of December 31, 2020 $ 113.3 $ 19.3 $ 2.1 $ (110.3) $ 10.3 $ 1.6 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 (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	AEP December 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input Low High Average (in millions) Energy Contracts $ 213.5 $ 169.7 Discounted Cash Flow Forward Market Price (a) (c) $ 5.33 $ 100.47 $ 32.73 Natural Gas Contracts — 1.7 Discounted Cash Flow Forward Market Price (b) (c) 2.18 2.77 2.40 FTRs 42.8 3.4 Discounted Cash Flow Forward Market Price (a) (c) (15.08) 9.66 0.19 Other Investments 31.8 — Black-Scholes Model Liquidity Adjustment (d) 10 % 20 % 15 % Total $ 288.1 $ 174.8 December 31, 2019 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 APCo December 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ 1.0 $ 0.6 Discounted Cash Flow Forward Market Price $ 10.84 $ 41.09 $ 25.08 FTRs 18.9 — Discounted Cash Flow Forward Market Price 0.04 5.61 1.13 Total $ 19.9 $ 0.6 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 I&M December 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ 0.6 $ 0.3 Discounted Cash Flow Forward Market Price $ 10.84 $ 41.09 $ 25.08 FTRs 1.9 0.1 Discounted Cash Flow Forward Market Price (1.96) 3.69 0.33 Total $ 2.5 $ 0.4 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 OPCo December 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ — $ 110.3 Discounted Cash Flow Forward Market Price $ 16.19 $ 46.98 $ 28.30 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 PSO December 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) FTRs $ 10.3 $ — Discounted Cash Flow Forward Market Price $ (6.93) $ 0.48 $ (1.93) 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) SWEPCo December 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input Low High Average (c) (in millions) Natural Gas Contracts $ — $ 1.7 Discounted Cash Flow Forward Market Price (b) $ 2.18 $ 2.77 $ 2.41 FTRs 3.3 — Discounted Cash Flow Forward Market Price (a) (6.93) 0.48 (1.93) Total $ 3.3 $ 1.7 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 (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. (d) Represents percentage discount applied to the publically available share price.
Sensitivity of Fair Value Measurements	Uncertainty of Fair Value Measurements Significant Unobservable Input Position Change in Input Impact on Fair Value Forward Market Price Buy Increase (Decrease) Higher (Lower) Forward Market Price Sell Increase (Decrease) Lower (Higher) Liquidity Adjustment Buy Increase (Decrease) Lower (Higher)

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Details of Income Taxes as Reported	Year Ended December 31, 2020 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Federal: Current $ (138.2) $ 5.2 $ 22.2 $ 21.4 $ 11.3 $ (26.6) $ (11.4) $ (13.6) Deferred 146.9 (15.4) 65.4 (27.1) (20.6) 74.0 8.3 19.6 Total Federal 8.7 (10.2) 87.6 (5.7) (9.3) 47.4 (3.1) 6.0 State and Local: Current (16.7) (0.1) 2.8 9.3 1.9 (5.4) 0.1 (8.2) Deferred 48.5 (0.9) 16.3 0.7 (0.1) 3.2 8.2 11.6 Total State and Local 31.8 (1.0) 19.1 10.0 1.8 (2.2) 8.3 3.4 Income Tax Expense (Benefit) $ 40.5 $ (11.2) $ 106.7 $ 4.3 $ (7.5) $ 45.2 $ 5.2 $ 9.4 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 (71.6) (24.7) 71.7 (126.1) (57.1) 40.6 (26.0) (10.0) 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 61.7 — 19.6 (0.6) 0.8 3.2 7.8 (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 122.0 (17.9) 82.3 (24.5) (48.8) (36.9) (36.7) (1.9) 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 (5.8) (0.1) 16.6 7.8 1.2 0.7 6.3 1.7 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
Reconciliation of Federal Statutory Tax Rate to Reported Tax Rate	AEP Years Ended December 31, 2020 2019 2018 (in millions) Net Income $ 2,196.7 $ 1,919.8 $ 1,931.3 Less: Equity Earnings – Dolet Hills (2.9) (3.0) (2.7) Income Tax Expense (Benefit) 40.5 (12.9) 115.3 Pretax Income $ 2,234.3 $ 1,903.9 $ 2,043.9 Income Taxes on Pretax Income at Statutory Rate (21%) $ 469.2 $ 399.8 $ 429.2 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 26.5 20.4 24.6 Investment Tax Credit Amortization (18.8) (13.0) (20.4) Production Tax Credits (83.1) (59.6) (10.3) State and Local Income Taxes, Net 25.1 52.2 19.7 Removal Costs (18.6) (22.2) (18.6) AFUDC (32.5) (37.1) (29.4) Tax Reform Adjustments — — (10.9) Tax Reform Excess ADIT Reversal (268.2) (353.2) (257.2) CARES Act (48.0) — — Other (11.1) (0.2) (11.4) Income Tax Expense (Benefit) $ 40.5 $ (12.9) $ 115.3 Effective Income Tax Rate 1.8 % (0.7) % 5.6 % AEP Texas Years Ended December 31, 2020 2019 2018 (in millions) Net Income $ 241.0 $ 178.3 $ 211.3 Income Tax Expense (Benefit) (11.2) (53.6) 20.8 Pretax Income $ 229.8 $ 124.7 $ 232.1 Income Taxes on Pretax Income at Statutory Rate (21%) $ 48.3 $ 26.2 $ 48.7 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 1.0 1.0 0.7 Investment Tax Credit Amortization (1.1) (1.2) (2.3) State and Local Income Taxes, Net (0.8) 2.3 1.3 AFUDC (4.1) (3.2) (4.2) Parent Company Loss Benefit (4.5) (3.8) (3.0) Tax Reform Adjustments — — (11.0) Tax Reform Excess ADIT Reversal (47.9) (73.4) (11.8) Other (2.1) (1.5) 2.4 Income Tax Expense (Benefit) $ (11.2) $ (53.6) $ 20.8 Effective Income Tax Rate (4.9) % (43.0) % 9.0 % AEPTCo Years Ended December 31, 2020 2019 2018 (in millions) Net Income $ 423.4 $ 439.7 $ 315.9 Income Tax Expense 106.7 117.4 84.1 Pretax Income $ 530.1 $ 557.1 $ 400.0 Income Taxes on Pretax Income at Statutory Rate (21%) $ 111.3 $ 117.0 $ 84.0 Increase (Decrease) in Income Taxes Resulting from the Following Items: State and Local Income Taxes, Net 15.1 17.4 12.6 AFUDC (15.5) (17.7) (14.1) Parent Company Loss Benefit (7.0) (4.2) (0.6) Other 2.8 4.9 2.2 Income Tax Expense $ 106.7 $ 117.4 $ 84.1 Effective Income Tax Rate 20.1 % 21.1 % 21.0 % APCo Years Ended December 31, 2020 2019 2018 (in millions) Net Income $ 369.7 $ 306.3 $ 367.8 Income Tax Expense (Benefit) 4.3 (78.0) (44.9) Pretax Income $ 374.0 $ 228.3 $ 322.9 Income Taxes on Pretax Income at Statutory Rate (21%) $ 78.5 $ 47.9 $ 67.8 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 12.7 10.8 9.4 State and Local Income Taxes, Net 7.9 9.0 9.1 Removal Costs (5.7) (6.4) (7.9) AFUDC (4.5) (5.2) (4.3) Parent Company Loss Benefit (6.2) (4.1) (3.6) Tax Reform Excess ADIT Reversal (72.3) (130.4) (108.5) Federal Return to Provision (7.2) (1.0) (6.6) Other 1.1 1.4 (0.3) Income Tax Expense (Benefit) $ 4.3 $ (78.0) $ (44.9) Effective Income Tax Rate 1.1 % (34.2) % (13.9) % I&M Years Ended December 31, 2020 2019 2018 (in millions) Net Income $ 284.8 $ 269.4 $ 261.3 Income Tax Expense (Benefit) (7.5) (10.6) 29.1 Pretax Income $ 277.3 $ 258.8 $ 290.4 Income Taxes on Pretax Income at Statutory Rate (21%) $ 58.2 $ 54.3 $ 61.0 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 1.6 4.0 1.5 Investment Tax Credit Amortization (4.5) (3.6) (4.7) State and Local Income Taxes, Net 1.5 (1.2) 13.4 Removal Costs (10.5) (12.8) (8.0) AFUDC (2.4) (4.1) (2.5) Parent Company Loss Benefit (6.4) (3.3) (2.3) Tax Reform Excess ADIT Reversal (46.8) (42.5) (25.8) Federal Return to Provision 1.9 (0.3) (4.6) Other (0.1) (1.1) 1.1 Income Tax Expense (Benefit) $ (7.5) $ (10.6) $ 29.1 Effective Income Tax Rate (2.7) % (4.1) % 10.0 % OPCo Years Ended December 31, 2020 2019 2018 (in millions) Net Income $ 271.4 $ 297.1 $ 325.5 Income Tax Expense 45.2 34.9 24.0 Pretax Income $ 316.6 $ 332.0 $ 349.5 Income Taxes on Pretax Income at Statutory Rate (21%) $ 66.5 $ 69.7 $ 73.4 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 3.7 (1.4) 2.4 State and Local Income Taxes, Net (1.7) 3.4 4.2 AFUDC (2.6) (3.8) (2.1) Parent Company Loss Benefit — (1.8) (6.0) Tax Reform Excess ADIT Reversal (27.2) (27.3) (51.0) Federal Return to Provision 6.5 (3.7) 0.2 Other — (0.2) 2.9 Income Tax Expense $ 45.2 $ 34.9 $ 24.0 Effective Income Tax Rate 14.3 % 10.5 % 6.9 % PSO Years Ended December 31, 2020 2019 2018 (in millions) Net Income $ 123.0 $ 137.6 $ 83.2 Income Tax Expense 5.2 7.5 5.0 Pretax Income $ 128.2 $ 145.1 $ 88.2 Income Taxes on Pretax Income at Statutory Rate (21%) $ 26.9 $ 30.5 $ 18.5 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 1.1 0.6 0.7 Investment Tax Credit Amortization (2.1) (0.5) (1.7) State and Local Income Taxes, Net 6.5 6.3 4.8 Parent Company Loss Benefit (0.2) (2.1) (1.4) Tax Reform Excess ADIT Reversal (25.5) (24.5) (15.5) Other (1.5) (2.8) (0.4) Income Tax Expense $ 5.2 $ 7.5 $ 5.0 Effective Income Tax Rate 4.1 % 5.2 % 5.7 % SWEPCo Years Ended December 31, 2020 2019 2018 (in millions) Net Income $ 183.7 $ 162.2 $ 152.2 Less: Equity Earnings – Dolet Hills (2.9) (3.0) (2.7) Income Tax Expense (Benefit) 9.4 (4.7) 20.4 Pretax Income $ 190.2 $ 154.5 $ 169.9 Income Taxes on Pretax Income at Statutory Rate (21%) $ 39.9 $ 32.4 $ 35.7 Increase (Decrease) in Income Taxes Resulting from the Following Items: Depreciation 1.9 1.9 1.9 Depletion (3.4) (3.4) (3.4) State and Local Income Taxes, Net 2.7 (1.3) 3.2 AFUDC (1.5) (1.4) (1.3) Parent Company Loss Benefit (5.6) (1.6) (0.6) Tax Reform Excess ADIT Reversal (21.9) (29.9) (16.0) Other (2.7) (1.4) 0.9 Income Tax Expense (Benefit) $ 9.4 $ (4.7) $ 20.4 Effective Income Tax Rate 4.9 % (3.0) % 12.0 %
Reconciliation of Significant Temporary Differences	AEP December 31, 2020 2019 (in millions) Deferred Tax Assets $ 3,259.7 $ 3,246.1 Deferred Tax Liabilities (11,500.6) (10,834.3) Net Deferred Tax Liabilities $ (8,240.9) $ (7,588.2) Property Related Temporary Differences $ (7,340.5) $ (6,602.9) Amounts Due to Customers for Future Income Taxes 1,075.8 1,173.5 Deferred State Income Taxes (1,317.6) (1,198.0) Securitized Assets (140.0) (178.7) Regulatory Assets (391.6) (371.1) Accrued Nuclear Decommissioning (626.4) (557.4) Net Operating Loss Carryforward 112.9 77.6 Tax Credit Carryforward 323.6 247.2 Operating Lease Liability 183.7 182.6 Investment in Partnership (362.0) (446.6) All Other, Net 241.2 85.6 Net Deferred Tax Liabilities $ (8,240.9) $ (7,588.2) AEP Texas December 31, 2020 2019 (in millions) Deferred Tax Assets $ 183.6 $ 220.0 Deferred Tax Liabilities (1,200.3) (1,185.4) Net Deferred Tax Liabilities $ (1,016.7) $ (965.4) Property Related Temporary Differences $ (1,039.6) $ (973.5) Amounts Due to Customers for Future Income Taxes 114.4 126.7 Deferred State Income Taxes (29.1) (27.5) Securitized Transition Assets (90.2) (124.3) Regulatory Assets (47.4) (51.2) Operating Lease Liability 18.0 17.2 All Other, Net 57.2 67.2 Net Deferred Tax Liabilities $ (1,016.7) $ (965.4) AEPTCo December 31, 2020 2019 (in millions) Deferred Tax Assets $ 166.5 $ 162.9 Deferred Tax Liabilities (1,073.4) (980.7) Net Deferred Tax Liabilities $ (906.9) $ (817.8) Property Related Temporary Differences $ (937.8) $ (847.1) Amounts Due to Customers for Future Income Taxes 118.9 119.9 Deferred State Income Taxes (98.3) (86.1) Net Operating Loss Carryforward 13.2 12.3 All Other, Net (2.9) (16.8) Net Deferred Tax Liabilities $ (906.9) $ (817.8) APCo December 31, 2020 2019 (in millions) Deferred Tax Assets $ 500.6 $ 486.2 Deferred Tax Liabilities (2,250.5) (2,167.0) Net Deferred Tax Liabilities $ (1,749.9) $ (1,680.8) Property Related Temporary Differences $ (1,412.0) $ (1,420.0) Amounts Due to Customers for Future Income Taxes 198.3 222.8 Deferred State Income Taxes (336.5) (337.2) Securitized Assets (44.7) (49.3) Regulatory Assets (114.8) (71.0) Operating Lease Liability 16.7 16.5 All Other, Net (56.9) (42.6) Net Deferred Tax Liabilities $ (1,749.9) $ (1,680.8) I&M December 31, 2020 2019 (in millions) Deferred Tax Assets $ 989.5 $ 970.5 Deferred Tax Liabilities (2,053.9) (1,950.2) Net Deferred Tax Liabilities $ (1,064.4) $ (979.7) Property Related Temporary Differences $ (409.2) $ (430.7) Amounts Due to Customers for Future Income Taxes 147.9 169.6 Deferred State Income Taxes (211.1) (194.4) Regulatory Assets (16.5) (26.9) Accrued Nuclear Decommissioning (626.4) (557.4) Operating Lease Liability 46.6 61.9 All Other, Net 4.3 (1.8) Net Deferred Tax Liabilities $ (1,064.4) $ (979.7) OPCo December 31, 2020 2019 (in millions) Deferred Tax Assets $ 210.8 $ 202.3 Deferred Tax Liabilities (1,165.9) (1,051.6) Net Deferred Tax Liabilities $ (955.1) $ (849.3) Property Related Temporary Differences $ (1,016.0) $ (890.8) Amounts Due to Customers for Future Income Taxes 121.1 130.2 Deferred State Income Taxes (40.7) (35.5) Regulatory Assets (53.7) (48.0) Operating Lease Liability 19.4 18.3 All Other, Net 14.8 (23.5) Net Deferred Tax Liabilities $ (955.1) $ (849.3) PSO December 31, 2020 2019 (in millions) Deferred Tax Assets $ 239.8 $ 257.4 Deferred Tax Liabilities (928.3) (885.7) Net Deferred Tax Liabilities $ (688.5) $ (628.3) Property Related Temporary Differences $ (661.8) $ (627.6) Amounts Due to Customers for Future Income Taxes 118.5 127.2 Deferred State Income Taxes (107.7) (100.4) Regulatory Assets (39.1) (44.6) Net Operating Loss Carryforward 12.9 10.2 All Other, Net (11.3) 6.9 Net Deferred Tax Liabilities $ (688.5) $ (628.3) SWEPCo December 31, 2020 2019 (in millions) Deferred Tax Assets $ 338.1 $ 359.6 Deferred Tax Liabilities (1,355.7) (1,300.5) Net Deferred Tax Liabilities $ (1,017.6) $ (940.9) Property Related Temporary Differences $ (985.1) $ (947.6) Amounts Due to Customers for Future Income Taxes 162.7 169.8 Deferred State Income Taxes (214.7) (200.3) Regulatory Assets (26.2) (30.2) Net Operating Loss Carryforward 33.4 38.2 All Other, Net 12.3 29.2 Net Deferred Tax Liabilities $ (1,017.6) $ (940.9)
State Net Income Tax Operating Loss Carryforwards	State Net Income Tax Operating Loss Years of Company State/Municipality Carryforward Expiration (in millions) AEP Arkansas $ 87.2 2021 - 2028 AEP Kentucky 163.7 2030 - 2037 AEP Louisiana 466.8 2025 - 2040 AEP Oklahoma 569.4 2034 - 2037 AEP Tennessee 31.1 2028 - 2035 AEP Virginia 29.4 2025 - 2037 AEP West Virginia 21.9 2029 - 2037 AEP Ohio Municipal 649.8 2021 - 2025 AEP Indiana 145.7 2039 AEP Colorado 95.7 NA AEP Pennsylvania 56.5 2030 - 2040 AEP New Jersey 60.2 2036 - 2040 AEP Illinois 15.6 2031 AEP Michigan 14.9 2029 AEPTCo Oklahoma 195.4 2034 - 2037 AEPTCo Ohio Municipal 18.4 2023 I&M West Virginia 2.5 2032 - 2037 PSO Oklahoma 354.5 2034 - 2037 SWEPCo Arkansas 86.4 2021 - 2024 SWEPCo Louisiana 454.3 2032 - 2037
Summary of Tax Credit Carryforwards	Total Federal Total State Tax Credit Tax Credit Company Carryforward Carryforward (in millions) AEP $ 323.6 $ 38.4 AEP Texas 1.2 — AEPTCo 0.1 — APCo 1.6 — I&M 9.7 — OPCo 0.5 — PSO 0.5 38.4 SWEPCo 1.3 —
Reconciliation of Beginning and Ending Unrecognized Tax Benefits	AEP 2020 2019 2018 (in millions) Balance as of January 1, $ 24.1 $ 14.6 $ 86.6 Increase – Tax Positions Taken During a Prior Period 0.6 8.8 0.1 Decrease – Tax Positions Taken During a Prior Period (14.5) (2.1) — Increase – Tax Positions Taken During the Current Year 3.0 2.8 — 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, $ 13.2 $ 24.1 $ 14.6

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Lease Rental Costs	Year Ended December 31, 2020 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Operating Lease Cost $ 279.6 $ 17.4 $ 2.6 $ 19.1 $ 101.5 $ 17.1 $ 7.8 $ 9.4 Finance Lease Cost: Amortization of Right-of-Use Assets 61.9 6.3 — 7.4 6.5 4.7 3.5 10.9 Interest on Lease Liabilities 15.4 1.5 — 2.7 3.1 0.9 0.7 2.2 Total Lease Rental Costs (a) $ 356.9 $ 25.2 $ 2.6 $ 29.2 $ 111.1 $ 22.7 $ 12.0 $ 22.5 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 (a) Excludes variable and short-term lease costs, which were immaterial for the twelve months ended December 31, 2020 and December 31, 2019.	[1]
Supplemental Balance Sheet Information Related to Leases	December 31, 2020 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo Weighted-Average Remaining Lease Term (years): Operating Leases 5.30 6.51 2.01 6.27 3.50 7.44 7.03 7.54 Finance Leases 5.43 6.07 0.00 5.75 5.79 5.90 6.16 4.95 Weighted-Average Discount Rate: Operating Leases 3.44 % 3.60 % 1.51 % 3.48 % 3.42 % 3.60 % 3.39 % 3.45 % Finance Leases 5.68 % 4.39 % — % 7.33 % 8.29 % 4.25 % 4.35 % 4.77 % 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, 2020 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 $ 280.3 $ 17.1 $ 2.6 $ 19.2 $ 102.2 $ 16.9 $ 7.7 $ 9.4 Operating Cash Flows Used for Finance Leases 15.4 1.5 — 2.7 3.1 0.9 0.7 2.2 Financing Cash Flows Used for Finance Leases 61.7 6.3 — 7.4 6.5 4.7 3.5 10.9 Non-cash Acquisitions Under Operating Leases $ 161.7 $ 15.8 $ 1.8 $ 16.2 $ 18.1 $ 18.1 $ 12.3 $ 18.4 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, 2020 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Property, Plant and Equipment Under Finance Leases: Generation $ 138.2 $ — $ — $ 42.8 $ 28.8 $ — $ 0.7 $ 37.7 Other Property, Plant and Equipment 322.8 49.7 — 20.3 40.2 31.4 23.0 52.4 Total Property, Plant and Equipment 461.0 49.7 — 63.1 69.0 31.4 23.7 90.1 Accumulated Amortization 176.8 16.6 — 21.4 27.3 9.8 8.7 36.5 Net Property, Plant and Equipment Under Finance Leases $ 284.2 $ 33.1 $ — $ 41.7 $ 41.7 $ 21.6 $ 15.0 $ 53.6 Obligations Under Finance Leases: Noncurrent Liability $ 231.0 $ 26.8 $ — $ 34.4 $ 35.3 $ 16.9 $ 11.9 $ 44.6 Liability Due Within One Year 58.1 6.3 — 7.3 6.4 4.7 3.1 10.7 Total Obligations Under Finance Leases $ 289.1 $ 33.1 $ — $ 41.7 $ 41.7 $ 21.6 $ 15.0 $ 55.3 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
Operating Lease Assets and Related Obligations	December 31, 2020 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Operating Lease Assets $ 866.4 $ 84.1 $ 1.6 $ 78.8 $ 218.1 $ 92.0 $ 42.6 $ 48.5 Obligations Under Operating Leases: Noncurrent Liability $ 638.4 $ 71.0 $ 0.4 $ 64.4 $ 135.9 $ 79.5 $ 36.2 $ 44.1 Liability Due Within One Year 241.3 14.5 1.2 14.9 85.6 13.1 6.5 7.9 Total Obligations Under Operating Leases $ 879.7 $ 85.5 $ 1.6 $ 79.3 $ 221.5 $ 92.6 $ 42.7 $ 52.0 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) 2021 $ 72.2 $ 7.6 $ — $ 9.9 $ 9.3 $ 5.5 $ 3.6 $ 13.1 2022 64.0 6.9 — 9.4 8.6 4.6 3.1 11.8 2023 56.2 6.2 — 8.7 7.9 3.9 2.7 10.9 2024 63.5 5.4 — 8.1 11.1 3.3 2.3 15.3 2025 32.7 4.0 — 7.0 5.5 2.2 1.6 5.7 Later Years 48.9 7.8 — 6.4 12.2 4.9 3.8 5.8 Total Future Minimum Lease Payments 337.5 37.9 — 49.5 54.6 24.4 17.1 62.6 Less: Imputed Interest 48.4 4.8 — 7.8 12.9 2.8 2.1 7.3 Estimated Present Value of Future Minimum Lease Payments $ 289.1 $ 33.1 $ — $ 41.7 $ 41.7 $ 21.6 $ 15.0 $ 55.3 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) 2021 $ 270.8 $ 17.5 $ 1.2 $ 17.7 $ 92.5 $ 16.6 $ 7.9 $ 10.1 2022 263.3 16.4 0.2 17.0 92.5 16.0 7.6 9.6 2023 94.2 14.8 0.1 14.2 11.4 14.9 7.3 8.4 2024 81.6 13.3 0.1 11.3 10.0 13.2 6.5 6.9 2025 68.0 10.9 — 8.5 8.9 11.5 5.4 5.8 Later Years 193.0 23.9 — 20.0 21.8 34.0 13.3 17.4 Total Future Minimum Lease Payments 970.9 96.8 1.6 88.7 237.1 106.2 48.0 58.2 Less: Imputed Interest 91.2 11.3 — 9.4 15.6 13.6 5.3 6.2 Estimated Present Value of Future Minimum Lease Payments $ 879.7 $ 85.5 $ 1.6 $ 79.3 $ 221.5 $ 92.6 $ 42.7 $ 52.0 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
Maximum Potential Loss	Company Maximum (in millions) AEP $ 50.3 AEP Texas 11.7 APCo 6.6 I&M 4.4 OPCo 8.1 PSO 4.8 SWEPCo 5.4
Future Minimum Lease Payments	Future Minimum Lease Payments AEP (a) I&M (in millions) 2021 $ 147.8 $ 73.9 2022 147.6 73.8 Total Future Minimum Lease Payments $ 295.4 $ 147.7 (a) AEP’s future minimum lease payments include equal shares from AEGCo and I&M.
[1]	Excludes variable and short-term lease costs, which were immaterial for the twelve months ended December 31, 2020 and December 31, 2019.

Financing Activities (Tables)

Financing Activities (Tables)	12 Months Ended
	Dec. 31, 2020
AEP Common Stock	Shares of AEP Common Stock Issued Held in Treasury 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 Issued 2,434,723 — Balance, December 31, 2020 516,808,354 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, 2020 2020 2019 2020 2019 AEP (in millions) Senior Unsecured Notes 2020-2050 3.97% 0.70%-8.13% 2.15%-8.13% $ 25,116.1 $ 21,180.7 Pollution Control Bonds (a) 2020-2036 (b) 2.39% 0.18%-4.63% 1.35%-5.38% 1,936.7 1,998.8 Notes Payable – Nonaffiliated (c) 2020-2032 2.34% 0.84%-6.37% 2.42%-6.37% 239.1 234.3 Securitization Bonds 2020-2029 (d) 2.78% 2.01%-3.77% 1.98%-5.31% 716.4 1,025.1 Spent Nuclear Fuel Obligation (e) 281.2 279.8 Junior Subordinated Notes (f) 2022-2023 2.32% 1.30%-3.40% 3.40% 1,624.1 787.8 Other Long-term Debt 2020-2059 1.59% 0.81%-13.72% 1.15%-13.718% 1,158.9 1,219.0 Total Long-term Debt Outstanding $ 31,072.5 $ 26,725.5 AEP Texas Senior Unsecured Notes 2022-2050 3.70% 2.10%-6.76% 2.40%-6.76% $ 3,687.6 $ 3,090.9 Pollution Control Bonds 2020-2030 (b) 3.42% 0.90%-4.55% 1.75%-4.55% 439.7 490.3 Securitization Bonds 2020-2029 (d) 2.55% 2.06%-2.84% 1.98%-5.31% 492.6 776.8 Other Long-term Debt 2022-2059 1.41% 1.40%-4.50% 3.05%-4.50% 200.5 200.4 Total Long-term Debt Outstanding $ 4,820.4 $ 4,558.4 AEPTCo Senior Unsecured Notes 2021-2050 3.83% 3.10%-5.52% 3.10%-5.52% $ 3,948.5 $ 3,427.3 Total Long-term Debt Outstanding $ 3,948.5 $ 3,427.3 APCo Senior Unsecured Notes 2021-2050 4.94% 3.30%-7.00% 3.30%-7.00% $ 3,937.2 $ 3,442.7 Pollution Control Bonds (a) 2020-2036 (b) 1.77% 0.19%-4.63% 1.67%-5.38% 546.3 546.1 Securitization Bonds 2023-2028 (d) 3.29% 2.01%-3.77% 2.008%-3.772% 223.8 248.3 Other Long-term Debt 2022-2026 1.51% 1.32%-13.72% 2.97%-13.718% 126.8 126.7 Total Long-term Debt Outstanding $ 4,834.1 $ 4,363.8 I&M Senior Unsecured Notes 2023-2048 4.38% 3.20%-6.05% 3.20%-6.05% $ 2,152.2 $ 2,150.7 Pollution Control Bonds (a) 2021-2025 (b) 2.21% 0.18%-3.05% 1.79%-3.05% 240.5 240.0 Notes Payable – Nonaffiliated (c) 2020-2025 1.06% 0.84%-1.29% 2.42%-2.80% 146.7 168.7 Spent Nuclear Fuel Obligation (e) 281.2 279.8 Other Long-term Debt 2021-2025 1.49% 1.28%-6.00% 2.93%-6.00% 209.3 211.0 Total Long-term Debt Outstanding $ 3,029.9 $ 3,050.2 OPCo Senior Unsecured Notes 2021-2049 4.82% 2.60%-6.60% 4.00%-6.60% $ 2,429.4 $ 2,081.0 Other Long-term Debt 2028 1.15% 1.15% 1.15% 0.8 1.0 Total Long-term Debt Outstanding $ 2,430.2 $ 2,082.0 PSO Senior Unsecured Notes 2021-2049 4.55% 3.05%-6.63% 3.05%-6.625% $ 1,246.3 $ 1,245.6 Pollution Control Bonds 2020 4.45% — 12.7 Other Long-term Debt 2022-2027 1.47% 1.42%-3.00% 3.00%-3.20% 127.5 127.9 Total Long-term Debt Outstanding $ 1,373.8 $ 1,386.2 SWEPCo Senior Unsecured Notes 2022-2048 4.04% 2.75%-6.20% 2.75%-6.20% $ 2,430.8 $ 2,428.9 Notes Payable – Nonaffiliated (c) 2024-2032 5.30% 4.58%-6.37% 4.58%-6.37% 62.4 65.6 Other Long-term Debt 2021-2035 2.99% 2.25%-4.68% 3.08%-4.68% 143.2 161.1 Total Long-term Debt Outstanding $ 2,636.4 $ 2,655.6 (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. Consequently, these bonds have been classified for maturity purposes as Long-term Debt Due Within One Year - Nonaffiliated on the balance sheets. (b) Certain Pollution Control Bonds are subject to redemption earlier than the maturity date. (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) 2021 $ 2,086.1 $ 88.7 $ 50.0 $ 518.3 $ 369.6 $ 500.1 $ 0.5 $ 106.2 2022 3,538.4 (a) 716.0 104.0 355.4 45.1 0.1 375.5 281.2 2023 2,659.3 (b) 278.5 60.0 26.6 273.9 0.1 0.5 6.2 2024 723.4 96.0 95.0 113.5 8.1 0.1 0.6 31.2 2025 1,726.3 324.5 90.0 443.9 151.5 0.1 125.6 6.2 After 2025 20,599.2 3,357.0 3,591.0 3,418.3 2,206.2 1,950.3 875.8 2,225.5 Principal Amount 31,332.7 4,860.7 3,990.0 4,876.0 3,054.4 2,450.8 1,378.5 2,656.5 Unamortized Discount, Net and Debt Issuance Costs (260.2) (40.3) (41.5) (41.9) (24.5) (20.6) (4.7) (20.1) Total Long-term Debt Outstanding $ 31,072.5 $ 4,820.4 $ 3,948.5 $ 4,834.1 $ 3,029.9 $ 2,430.2 $ 1,373.8 $ 2,636.4 (a) Amount includes $805 million of Junior Subordinated Notes. See “Equity Units” section below for additional information. (b) Amount includes $850 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 $ 2,369.5 (a) $ 694.0 $ — $ 175.1 $ 519.7 $ — $ 182.3 $ 571.9 (a) Includes the restrictions of consolidated and non-consolidated subsidiaries.
Lines of Credit and Short-term Debt	December 31, 2020 2019 Company Type of Debt Outstanding Interest Outstanding Interest (in millions) (in millions) AEP Securitized Debt for Receivables (b) $ 592.0 0.85 % $ 710.0 2.42 % AEP Commercial Paper 1,852.3 0.29 % 2,110.0 2.10 % SWEPCo Notes Payable 35.0 2.55 % 18.3 3.29 % Total Short-term Debt $ 2,479.3 $ 2,838.3 (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, 2020: 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, 2020 Limit (in millions) AEP Texas $ 320.4 $ 313.4 $ 132.0 $ 139.0 $ (67.1) $ 500.0 AEPTCo 358.4 259.7 116.3 55.0 (155.4) 820.0 (a) APCo 434.3 189.0 242.8 76.3 2.8 500.0 I&M 218.6 13.4 114.5 13.3 (89.7) 500.0 OPCo 353.9 32.8 182.4 25.2 (259.2) 500.0 PSO 155.4 57.1 72.3 28.4 (155.4) 300.0 SWEPCo 178.9 — 113.0 — (124.6) 350.0 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 (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, 2020: 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, 2020 (in millions) AEP Texas $ 7.5 $ 7.1 $ 7.1 SWEPCo 2.1 2.1 2.1 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
Direct Borrowing Activity	Year Ended December 31, 2020: 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, 2020 December 31, 2020 Borrowing Limit (in millions) $ 1.4 $ 215.3 $ 1.3 $ 132.6 $ 1.2 $ 109.0 $ 50.0 (a) 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) (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, 2020 2019 2018 Maximum Interest Rate 2.70 % 3.43 % 2.97 % Minimum Interest Rate 0.27 % 1.77 % 1.81 %
Average Interest Rates for Funds Borrowed from and Loaned to Utility Money Pool	Average Interest Rate for Funds Borrowed Average Interest Rate for Funds Loaned Company 2020 2019 2018 2020 2019 2018 AEP Texas 1.51 % 2.63 % 2.26 % 0.81 % 2.03 % 2.29 % AEPTCo 1.29 % 2.64 % 2.27 % 1.99 % 2.41 % 2.10 % APCo 2.12 % 2.45 % 2.26 % 0.85 % 2.66 % 2.21 % I&M 1.07 % 2.34 % 2.16 % 1.18 % 2.60 % 2.08 % OPCo 0.99 % 2.67 % 2.18 % 2.06 % 2.68 % 2.47 % PSO 0.92 % 2.85 % 2.27 % 1.95 % 2.27 % 1.98 % SWEPCo 1.27 % 2.72 % 2.31 % — % 2.22 % 2.00 %
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 2020 AEP Texas 2.70 % 0.27 % 1.18 % 2020 SWEPCo 2.70 % 0.27 % 1.18 % 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 %
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 2020 2.70 % 0.27 % 2.70 % 0.27 % 1.20 % 1.13 % 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 %
Comparative Accounts Receivable Information	Years Ended December 31, 2020 2019 2018 (dollars in millions) Effective Interest Rates on Securitization of Accounts Receivable 0.85 % 2.42 % 2.16 % Net Uncollectible Accounts Receivable Written Off $ 15.3 $ 26.6 $ 27.6
Customer Accounts Receivable Managed Portfolio	December 31, 2020 2019 (in millions) Accounts Receivable Retained Interest and Pledged as Collateral Less Uncollectible Accounts $ 958.4 $ 841.8 Short-term – Securitized Debt of Receivables 592.0 710.0 Delinquent Securitized Accounts Receivable 62.3 39.6 Bad Debt Reserves Related to Securitization 60.0 32.1 Unbilled Receivables Related to Securitization 296.8 266.8
Accounts Receivable and Accrued Unbilled Revenues	December 31, Company 2020 2019 (in millions) APCo $ 136.0 $ 120.9 I&M 170.5 141.8 OPCo 398.8 330.3 PSO 85.0 101.1 SWEPCo 158.6 125.2
Fees Paid to AEP Credit for Customer Accounts Receivable Sold	Years Ended December 31, Company 2020 2019 2018 (in millions) APCo $ 5.2 $ 7.4 $ 7.0 I&M 7.9 11.1 9.2 OPCo 24.1 27.1 26.3 PSO 4.8 7.8 7.9 SWEPCo 6.7 10.2 8.9
Proceeds on Sale of Receivables to AEP Credit	Years Ended December 31, Company 2020 2019 2018 (in millions) APCo $ 1,272.9 $ 1,310.3 $ 1,421.0 I&M 1,891.8 1,824.2 1,843.0 OPCo 2,366.2 2,293.6 2,674.5 PSO 1,221.0 1,442.5 1,484.6 SWEPCo 1,593.8 1,618.5 1,736.1

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
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 2020 2019 2018 Awarded Shares (in thousands) 424.8 535.0 581.4 Weighted-Average Share Fair Value at Grant Date $ 116.56 $ 83.21 $ 67.21 Vesting Period (in years) 3 3 3 Performance Shares and AEP Career Shares Years Ended December 31, 2020 2019 2018 Awarded Shares (in thousands) (a) 73.4 66.4 80.2 Weighted-Average Fair Value at Grant Date $ 84.87 $ 88.73 $ 70.58 Vesting Period (in years) (b) (b) (b) (a) All awarded dividends in both 2020 and 2019 were equity awards and awarded dividends in 2018 were a mix of equity awards and liability awards.
Summary of Performance Scores and Performance Units Earned	Years Ended December 31, Performance Shares 2020 2019 2018 Certified Performance Score 128.2 % 132.7 % 136.7 % Performance Shares Earned 757,858 792,897 820,780 Performance Shares Mandatorily Deferred as AEP Career Shares 13,614 10,063 11,248 Performance Shares Voluntarily Deferred into the Incentive Compensation Deferral Program 26,936 49,392 56,826 Performance Shares to be Settled (a) 717,308 733,442 752,706 (a) Performance shares settled for the three-year periods ended December 31, 2020 and 2019 settled in AEP common stock. Performance units settled for the three-year period ended December 31, 2018 settled in cash. In all cases, the settlement of common stock or cash occurs in the quarter following the end of the year shown.
Summary of Cash Payouts for Performance Units and Career Shares	Years Ended December 31, Performance Shares and AEP Career Shares 2020 2019 2018 (in millions) Cash Settlements for Performance Units $ — $ 58.3 $ 66.9 AEP Common Stock Settlements for Performance Shares 75.4 — — AEP Common Stock Settlements for Career Share Distributions 1.9 6.6 5.1
Status of Nonvested Performance Units	Nonvested Performance Shares Shares Weighted (in thousands) Nonvested as of January 1, 2020 1,113.4 $ 73.64 Awarded 424.8 116.56 Dividends 53.8 84.91 Vested (a) (597.0) 66.45 Forfeited (56.4) 87.58 Nonvested as of December 31, 2020 938.6 98.05 (a) The vested Performance Shares will be converted to 717 thousand shares based on the closing share price on the day before settlement.
Monte Carlo Valuation Assumptions	Years Ended December 31, Assumptions 2020 2019 2018 Valuation Period (in years) (a) 2.87 2.87 2.87 Expected Volatility Minimum 13.67 % 14.83 % 14.77 % Expected Volatility Maximum 28.15 % 25.57 % 26.72 % Expected Volatility Average 16.39 % 17.39 % 17.90 % Dividend Rate (b) — % — % — % Risk Free Rate 1.40 % 2.49 % 2.34 % (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 2020 2019 2018 Awarded Units (in thousands) 268.7 304.8 260.0 Weighted-Average Grant Date Fair Value $ 94.38 $ 81.57 $ 67.96
Total Fair Value and Total Intrinsic Value of Restricted Shares and Restricted Stock Units Vested	Years Ended December 31, Restricted Stock Units 2020 2019 2018 (in millions) Fair Value of Restricted Stock Units Vested $ 22.9 $ 16.3 $ 16.6 Intrinsic Value of Restricted Stock Units Vested (a) 25.2 21.6 19.2 (a) Intrinsic value is calculated as market price at the vesting date.
Status of Nonvested Restricted Shares and Restricted Stock Units	Nonvested Restricted Stock Units Shares/Units Weighted (in thousands) Nonvested as of January 1, 2020 516.9 $ 75.55 Awarded 268.7 94.38 Vested (307.6) 74.58 Forfeited (30.0) 84.27 Nonvested as of December 31, 2020 448.0 86.56
Stock Unit Accumulation Plan for Non-employee Directors	Years Ended December 31, Stock Unit Accumulation Plan for Non-Employee Directors 2020 2019 2018 Awarded Units (in thousands) 12.1 10.0 11.4 Weighted-Average Grant Date Fair Value $ 83.80 $ 89.13 $ 70.41
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 2020 2019 2018 (in millions) Compensation Cost for Share-based Payment Arrangements (a) $ 53.8 $ 57.9 $ 53.2 Actual Tax Benefit 7.2 8.4 7.7 Total Compensation Cost Capitalized 20.4 20.0 19.7 (a) Compensation cost for share-based payment arrangements is included in Other Operation and Maintenance expenses on the statements of income.

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2020
Affiliated Revenues	Related Party Revenues AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Year Ended December 31, 2020 Direct Sales to East Affiliates $ — $ — $ 112.5 $ — $ — $ — $ — Auction Sales to OPCo (a) — — 5.3 3.1 — — — Direct Sales to AEPEP 87.5 — — — — — — Transmission Revenues — 885.0 49.1 2.9 16.6 — 37.4 Other Revenues 3.3 11.3 7.8 4.5 24.9 5.2 1.6 Total Affiliated Revenues $ 90.8 $ 896.3 $ 174.7 $ 10.5 $ 41.5 $ 5.2 $ 39.0 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 $ — $ — $ — $ — 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 $ — $ — $ — 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 (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, 2020 Auction Purchases from AEPEP (a) $ — $ 51.0 Auction Purchases from AEP Energy (a) — 58.7 Auction Purchases from AEPSC (a) — 10.0 Direct Purchases from AEGCo 172.8 — Total Affiliated Purchases $ 172.8 $ 119.7 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 (a) Refer to the Ohio Auctions section below for further information regarding this amount.
PJM Transmission Service Charges	Years Ended December 31, Company 2020 2019 2018 (in millions) APCo $ 243.2 $ 222.3 $ 128.3 I&M 145.9 143.5 91.4 OPCo 417.4 373.4 210.1
SPP Transmission Service Charges	Years Ended December 31, Company 2020 2019 2018 (in millions) PSO $ 69.7 $ 46.9 $ 65.9 SWEPCo 31.3 20.1 10.5
Joint License Agreement	Years Ended December 31, Billing Company 2020 2019 2018 (in millions) APCo $ 0.9 $ 0.2 $ — I&M 3.0 1.5 2.2 KPCo 0.4 0.3 0.2 OPCo 4.5 2.2 2.9 PSO 0.4 0.3 0.3 WPCo 0.2 0.1 —
Railcar Maintenance	Years Ended December 31, Company 2020 2019 2018 (in millions) I&M $ 0.9 $ 1.3 $ 1.5 PSO 0.7 0.8 0.7 SWEPCo 3.0 4.0 3.4
Barging, Urea Transloading and Other Services	Years Ended December 31, Company 2020 2019 2018 (in millions) AEGCo $ 10.6 $ 14.9 $ 19.9 APCo 43.7 38.9 35.1 KPCo 3.2 4.8 4.2 WPCo 3.3 4.8 4.2
Central Machine Shop	Years Ended December 31, Company 2020 2019 2018 (in millions) AGR $ 2.9 $ 0.8 $ 1.6 I&M 3.2 2.3 2.4 KPCo 0.9 1.4 1.7 PSO 0.9 1.1 0.5 SWEPCo 0.5 1.1 0.7
Related Party Sales of Property	Sales Years Ended December 31, Company 2020 2019 2018 (in millions) AEP Texas $ 0.9 $ 0.9 $ 0.3 AEPTCo 0.2 — — APCo 5.7 5.5 5.4 I&M 1.5 7.5 8.2 OPCo 7.0 7.0 10.7 PSO 1.1 0.8 1.0 SWEPCo 0.8 0.2 0.8
Related Party Purchases of Property	Purchases Years Ended December 31, Company 2020 2019 2018 (in millions) AEP Texas $ 1.5 $ 0.3 $ 0.1 AEPTCo 6.0 10.2 18.5 APCo 1.3 6.0 0.6 I&M 3.4 0.9 2.0 OPCo 1.2 3.0 2.8 PSO 0.4 0.5 1.3 SWEPCo 2.8 0.7 0.8
Charitable Contribution to AEP Foundation [Table Text Block]	Year Ended Company December 31, 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, 2020
Consolidated Assets And Liabilities Of Variable Interest Entities	American Electric Power Company, Inc. and Subsidiary Companies Variable Interest Entities December 31, 2020 Registrant Subsidiaries SWEPCo I&M AEP Texas Transition Funding AEP Texas Restoration Funding APCo (in millions) ASSETS Current Assets $ 88.0 $ 76.1 $ 61.2 $ 23.3 $ 16.8 Net Property, Plant and Equipment 97.3 138.9 — — — Other Noncurrent Assets 99.3 70.9 273.9 (a) 214.9 (b) 212.7 (c) Total Assets $ 284.6 $ 285.9 $ 335.1 $ 238.2 $ 229.5 LIABILITIES AND EQUITY Current Liabilities $ 57.7 $ 76.0 $ 69.8 $ 33.9 $ 28.7 Noncurrent Liabilities 225.3 209.9 246.5 203.1 198.9 Equity 1.6 — 18.8 1.2 1.9 Total Liabilities and Equity $ 284.6 $ 285.9 $ 335.1 $ 238.2 $ 229.5 (a) Includes an intercompany item eliminated in consolidation of $32 million. (b) Includes an intercompany item eliminated in consolidation of $9 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, 2020 Other Consolidated VIEs AEP Credit Protected Transource Energy Apple Blossom and Black Oak Santa Rita East (in millions) ASSETS Current Assets $ 960.4 $ 198.1 $ 22.2 $ 9.6 $ 6.0 Net Property, Plant and Equipment — — 458.7 223.1 453.1 Other Noncurrent Assets 12.9 — 3.7 12.1 — Total Assets $ 973.3 $ 198.1 $ 484.6 $ 244.8 $ 459.1 LIABILITIES AND EQUITY Current Liabilities $ 827.2 $ 43.1 $ 32.6 $ 5.3 $ 3.5 Noncurrent Liabilities 0.8 62.5 185.0 4.9 6.7 Equity 145.3 92.5 267.0 234.6 448.9 Total Liabilities and Equity $ 973.3 $ 198.1 $ 484.6 $ 244.8 $ 459.1 American Electric Power Company, Inc. and Subsidiary Companies Variable Interest Entities December 31, 2019 Registrant Subsidiaries SWEPCo I&M AEP Texas Transition Funding AEP Texas Restoration Funding 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 Transource Energy Desert Sky 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
SWEPCo's Investment In DHLC	December 31, 2020 2019 As Reported on Maximum As Reported on Maximum (in millions) Capital Contribution from SWEPCo $ 7.6 $ 7.6 $ 7.6 $ 7.6 Retained Earnings 20.4 20.4 17.5 17.5 SWEPCo’s Share of Obligations — 98.5 — 130.0 Total Investment in DHLC $ 28.0 $ 126.5 $ 25.1 $ 155.1
AEP's Investment In OVEC	December 31, 2020 2019 As Reported on Maximum 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) — 555.0 — 588.9 Total Investment in OVEC $ 4.4 $ 559.4 $ 4.4 $ 593.3
Purchased Power from OVEC	Years Ended December 31, Company 2020 2019 2018 (in millions) APCo $ 94.4 $ 104.5 $ 100.4 I&M 47.2 52.3 50.2 OPCo 120.8 132.7 127.5
Billings from Significant Variable Interest	Years Ended December 31, Company 2020 2019 2018 (in millions) AEP Texas $ 199.4 $ 206.6 $ 184.3 AEPTCo 270.3 242.3 220.4 APCo 294.9 308.3 295.6 I&M 210.2 184.8 173.5 OPCo 232.8 230.4 214.9 PSO 113.2 125.7 121.5 SWEPCo 161.8 169.5 164.4
Carrying Amount and Classification of Variable Interest in Accounts Payable	December 31, 2020 2019 Company As Reported on Maximum As Reported on Maximum (in millions) AEP Texas $ 30.5 $ 30.5 $ 32.4 $ 32.4 AEPTCo 45.9 45.9 33.4 33.4 APCo 42.8 42.8 44.1 44.1 I&M 27.1 27.1 28.6 28.6 OPCo 33.9 33.9 33.2 33.2 PSO 15.7 15.7 18.1 18.1 SWEPCo 22.0 22.0 23.4 23.4

Property, Plant and Equipment_2

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment	December 31, 2020 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Regulated Property, Plant and Equipment Generation $ 21,587.8 (a) $ — $ — $ 6,633.7 $ 5,264.7 $ — $ 1,480.7 $ 4,681.4 (a) Transmission 27,841.5 5,279.6 9,593.5 3,900.5 1,696.4 2,831.9 1,069.9 2,165.7 Distribution 23,972.1 4,580.8 — 4,464.3 2,594.6 5,708.3 2,853.0 2,382.5 Other 4,852.4 866.0 328.8 598.0 644.6 888.5 388.1 564.5 CWIP 3,815.0 (a) 614.1 1,422.6 484.6 362.4 362.3 128.7 228.3 (a) Less: Accumulated Depreciation 20,094.2 1,528.1 572.8 4,711.0 3,538.6 2,348.8 1,607.3 3,032.0 Total Regulated Property, Plant and Equipment - Net 61,974.6 9,812.4 10,772.1 11,370.1 7,024.1 7,442.2 4,313.1 6,990.4 Nonregulated Property, Plant and Equipment - Net 1,927.0 1.2 0.7 24.0 28.2 9.9 6.9 97.8 Total Property, Plant and Equipment - Net $ 63,901.6 $ 9,813.6 $ 10,772.8 $ 11,394.1 $ 7,052.3 $ 7,452.1 $ 4,320.0 $ 7,088.2 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 (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 2020 2019 2018 Functional Class of Property Annual Composite Depreciable Annual Composite Depreciable Annual Composite Depreciable (in years) (in years) (in years) Generation 2.7% - 6.3% 20 - 132 2.5% - 5.5% 20 - 132 2.4% - 4.0% 20 - 132 Transmission 2.0% - 2.6% 15 - 75 1.8% - 2.6% 15 - 81 1.6% - 2.7% 15 - 81 Distribution 2.7% - 3.7% 7 - 78 2.7% - 3.7% 7 - 78 2.7% - 3.6% 7 - 78 Other 2.8% - 11.3% 5 - 75 2.6% - 9.5% 5 - 75 2.3% - 9.8% 5 - 75 AEP Texas 2020 2019 2018 Functional Class of Property Annual Composite Depreciable Annual Composite Depreciable Annual Composite Depreciable (in years) (in years) (in years) Transmission 2.0% 50 - 75 1.8% 45 - 81 1.7% 45 - 81 Distribution 3.1% 7 - 70 3.5% 7 - 70 3.6% 7 - 70 Other 6.1% 5 - 50 6.3% 5 - 50 6.0% 5 - 50 AEPTCo 2020 2019 2018 Functional Class of Property Annual Composite Depreciable Annual Composite Depreciable Annual Composite Depreciable (in years) (in years) (in years) Transmission 2.4% 24 - 75 2.0% 24 - 75 1.9% 20 - 75 Other 6.3% 5 - 64 5.8% 5 - 64 5.6% 5 - 64 APCo 2020 2019 2018 Functional Class of Property Annual Composite Depreciable Annual Composite Depreciable Annual Composite Depreciable (in years) (in years) (in years) Generation 3.3% 35 - 118 3.2% 35 - 118 3.1% 35 - 112 Transmission 2.2% 15 - 75 1.8% 15 - 71 1.6% 15 - 68 Distribution 3.7% 12 - 57 3.7% 12 - 57 3.6% 10 - 57 Other 7.8% 5 - 55 7.2% 5 - 55 7.4% 5 - 55 I&M 2020 2019 2018 Functional Class of Property Annual Composite Depreciable Annual Composite Depreciable Annual Composite Depreciable (in years) (in years) (in years) Generation 4.6% 20 - 132 4.0% 20 - 132 3.4% 20 - 132 Transmission 2.3% 45 - 70 1.9% 50 - 73 1.8% 50 - 73 Distribution 3.4% 14 - 71 3.4% 9 - 75 3.1% 9 - 75 Other 10.2% 5 - 51 9.4% 5 - 50 8.9% 5 - 50 OPCo 2020 2019 2018 Functional Class of Property Annual Composite Depreciable Annual Composite Depreciable Annual Composite Depreciable (in years) (in years) (in years) Transmission 2.3% 39 - 60 2.3% 39 - 60 2.3% 39 - 60 Distribution 3.1% 14 - 65 3.1% 14 - 65 3.0% 14 - 65 Other 5.0% 5 - 50 4.9% 5 - 50 6.3% 5 - 50 PSO 2020 2019 2018 Functional Class of Property Annual Composite Depreciable Annual Composite Depreciable Annual Composite Depreciable (in years) (in years) (in years) Generation 3.1% 35 - 75 2.9% 35 - 75 2.9% 35 - 75 Transmission 2.2% 45 - 75 2.4% 45 - 75 2.3% 45 - 75 Distribution 2.9% 15 - 78 2.9% 15 - 78 2.9% 15 - 78 Other 5.7% 5 - 64 5.6% 5 - 64 6.3% 5 - 64 SWEPCo 2020 2019 2018 Functional Class of Property Annual Composite Depreciable Annual Composite Depreciable Annual Composite Depreciable (in years) (in years) (in years) Generation 2.7% 35 - 65 2.5% 40 - 70 2.4% 40 - 70 Transmission 2.3% 47 - 73 2.4% 50 - 73 2.2% 50 - 73 Distribution 2.7% 15 - 67 2.7% 25 - 70 2.7% 25 - 70 Other 8.5% 5 - 52 7.6% 5 - 55 8.0% 5 - 55
Depreciation, Depletion and Amortization - Unregulated	2020 2019 2018 Functional Class of Property Annual Composite Depreciable Annual Composite Depreciable Annual Composite Depreciable (in years) (in years) (in years) Generation 3.6% - 4.0% 15 - 59 3.2% - 21.2% 15 - 59 3.4% - 22.3% 15 - 59 Transmission 2.5% 30 - 40 2.5% 30 - 40 2.4% 40 Distribution NA NA 2.3% 40 2.3% 40 Other 16.1% 5 - 50 (a) 17.6% 5 - 50 (a) 16.3% 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. NA Not applicable.
Asset Retirement Obligation (ARO)	Company ARO as of December 31, 2019 Accretion Liabilities Liabilities Revisions in ARO as of December 31, 2020 (in millions) AEP (b)(c)(d)(e) $ 2,418.9 $ 102.4 $ 0.3 $ (188.0) $ 183.1 $ 2,516.7 AEP Texas (b)(e) 29.1 0.8 — (8.5) (16.8) 4.6 APCo (b)(e) 111.1 8.9 — (7.8) 200.9 313.1 I&M (b)(c)(e) 1,748.6 70.2 0.1 (0.2) (4.9) 1,813.8 OPCo (e) 1.8 0.1 — — — 1.9 PSO (b)(e) 52.2 3.1 — (3.1) (4.8) 47.4 SWEPCo (b)(d)(e) 212.2 10.7 — (10.9) 10.1 222.1 Company ARO as of December 31, 2018 Accretion Liabilities Liabilities Revisions in 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 (a) Unless discussed above, 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 $1.80 billion and $1.73 billion as of December 31, 2020 and 2019, respectively. (d) Includes ARO related to Sabine and DHLC. (e) Includes ARO related to asbestos removal.
Allowance For Equity Funds Used During Construction	Years Ended December 31, Company 2020 2019 2018 (in millions) AEP $ 148.1 $ 168.4 $ 132.5 AEP Texas 19.4 15.2 20.0 AEPTCo 74.0 84.3 70.6 APCo 14.6 16.6 13.2 I&M 11.5 19.4 11.9 OPCo 12.5 18.2 9.8 PSO 4.0 2.7 0.4 SWEPCo 7.7 6.8 6.0
Allowance For Borrowed Funds Used During Construction	Years Ended December 31, Company 2020 2019 2018 (in millions) AEP $ 66.0 $ 88.7 $ 73.6 AEP Texas 12.5 20.0 18.4 AEPTCo 25.5 32.2 26.1 APCo 7.9 9.3 8.4 I&M 5.7 8.9 7.4 OPCo 6.2 6.7 5.8 PSO 2.0 1.9 0.9 SWEPCo 3.9 4.0 4.8
Jointly-owned Electric Facilities	Registrant’s Share as of December 31, 2020 Fuel Percent of Utility Plant Construction Accumulated (in millions) AEP Dolet Hills Power Station, Unit 1 (a) Lignite 40.2 % $ 342.4 $ 4.6 $ 295.4 Flint Creek Generating Station, Unit 1 (b) Coal 50.0 % 377.2 3.0 116.0 Pirkey Power Plant, Unit 1 (b) Lignite 85.9 % 602.8 3.7 441.0 Oklaunion Power Station (f)(g) Coal 70.3 % — — — Turk Generating Plant (b) Coal 73.3 % 1,594.3 2.8 257.3 Total $ 2,916.7 $ 14.1 $ 1,109.7 AEP Texas Oklaunion Power Station (f)(g) Coal 54.7 % $ — $ — $ — I&M Rockport Generating Plant (c)(d)(e) Coal 50.0 % $ 1,228.5 $ 19.6 $ 677.3 PSO Oklaunion Power Station (f)(g) Coal 15.6 % $ — $ — $ — SWEPCo Dolet Hills Power Station, Unit 1 (a) Lignite 40.2 % $ 342.4 $ 4.6 $ 295.4 Flint Creek Generating Station, Unit 1 (b) Coal 50.0 % 377.2 3.0 116.0 Pirkey Power Plant, Unit 1 (b) Lignite 85.9 % 602.8 3.7 441.0 Turk Generating Plant (b) Coal 73.3 % 1,594.3 2.8 257.3 Total $ 2,916.7 $ 14.1 $ 1,109.7 Registrant’s Share as of December 31, 2019 Fuel Percent of Utility Plant Construction Accumulated (in millions) AEP Dolet Hills Power Station, Unit 1 (a) Lignite 40.2 % $ 337.3 $ 6.2 $ 216.5 Flint Creek Generating Station, Unit 1 (b) Coal 50.0 % 374.3 3.4 101.1 Pirkey Power Plant, Unit 1 (b) Lignite 85.9 % 607.8 7.7 416.8 Oklaunion Power Station (f)(g) Coal 70.3 % 106.6 0.1 91.7 Turk Generating Plant (b) Coal 73.3 % 1,593.3 1.7 225.8 Total $ 3,019.3 $ 19.1 $ 1,051.9 AEP Texas Oklaunion Power Station (f)(g) Coal 54.7 % $ 351.7 $ — $ 291.9 I&M Rockport Generating Plant (c)(d)(e) Coal 50.0 % $ 1,114.2 $ 105.5 $ 586.2 PSO Oklaunion Power Station (f)(g) Coal 15.6 % $ 106.6 $ 0.1 $ 91.7 SWEPCo Dolet Hills Power Station, Unit 1 (a) Lignite 40.2 % $ 337.3 $ 6.2 $ 216.5 Flint Creek Generating Station, Unit 1 (b) Coal 50.0 % 374.3 3.4 101.1 Pirkey Power Plant, Unit 1 (b) Lignite 85.9 % 607.8 7.7 416.8 Turk Generating Plant (b) Coal 73.3 % 1,593.3 1.7 225.8 Total $ 2,912.7 $ 19.0 $ 960.2 (a) Operated by CLECO, a nonaffiliated company. (b) Operated by SWEPCo. (c) Operated by I&M. (d) 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 for additional information. (e) AEGCo owns 50% of Unit 1 with I&M and 50% of capital additions for Unit 2. (f) Operated by PSO, which owned 15.6%. Also was jointly-owned (54.7%) by AEP Texas and various nonaffiliated companies. (g) Oklaunion Power Station was retired in September 2020 and sold to a nonaffiliated third-party in October 2020. See the “Dispositions” section of Note 7 for additional information.

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	12 Months Ended
	Dec. 31, 2020
Disaggregated Revenues from Contracts with Customers	Year Ended December 31, 2020 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 $ 3,606.8 $ 2,086.9 $ — $ — $ — $ — $ 5,693.7 Commercial Revenues 2,016.2 1,048.6 — — — — 3,064.8 Industrial Revenues 2,018.0 390.1 — — — (0.7) 2,407.4 Other Retail Revenues 155.6 42.5 — — — — 198.1 Total Retail Revenues 7,796.6 3,568.1 — — — (0.7) 11,364.0 Wholesale and Competitive Retail Revenues: Generation Revenues 588.3 — — 131.9 — — 720.2 Transmission Revenues (a) 334.5 467.0 1,257.0 — — (1,006.7) 1,051.8 Renewable Generation Revenues (b) — — — 60.9 — (1.6) 59.3 Retail, Trading and Marketing Revenues (c) — — — 1,486.9 (5.5) (103.0) 1,378.4 Total Wholesale and Competitive Retail Revenues 922.8 467.0 1,257.0 1,679.7 (5.5) (1,111.3) 3,209.7 Other Revenues from Contracts with Customers (b) 163.2 157.8 22.4 2.3 92.5 (148.6) 289.6 Total Revenues from Contracts with Customers 8,882.6 4,192.9 1,279.4 1,682.0 87.0 (1,260.6) 14,863.3 Other Revenues: Alternative Revenues (b) (3.2) 70.0 (80.6) — — 7.5 (6.3) Other Revenues (b) — 83.0 — 43.6 9.8 (74.9) 61.5 Total Other Revenues (3.2) 153.0 (80.6) 43.6 9.8 (67.4) 55.2 Total Revenues $ 8,879.4 $ 4,345.9 $ 1,198.8 $ 1,725.6 $ 96.8 $ (1,328.0) $ 14,918.5 (a) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $965 million. The remaining affiliated amounts were immaterial. (b) Amounts include affiliated and nonaffiliated revenues. (c) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $103 million. The remaining affiliated amounts were immaterial. 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 807.6 — — 254.8 — — 1,062.4 Transmission Revenues (a) 292.1 435.1 1,077.2 — — (825.0) 979.4 Renewable Generation Revenues (b) — — — 57.3 — — 57.3 Retail, Trading and Marketing Revenues (c) — — — 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 (b) 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 (b) (57.9) 32.3 (20.6) — — (66.9) (113.1) Other Revenues (b) — 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. (c) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $136 million. The remaining affiliated amounts were immaterial. 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 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 (c) — — — 50.8 — — 50.8 Retail, Trading and Marketing Revenues (d) — — — 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 (c) 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 (c) (15.9) (22.2) (60.4) — — 52.7 (45.8) Other Revenues (c) (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. (d) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $121 million. The remaining affiliated amounts were immaterial. (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, 2020 AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Retail Revenues: Residential Revenues $ 563.6 $ — $ 1,250.6 $ 794.1 $ 1,523.4 $ 579.4 $ 630.8 Commercial Revenues 366.7 — 517.0 499.3 682.0 320.1 466.7 Industrial Revenues 120.1 — 553.5 547.4 270.0 221.1 328.8 Other Retail Revenues 29.5 — 67.6 6.6 13.1 66.0 9.1 Total Retail Revenues 1,079.9 — 2,388.7 1,847.4 2,488.5 1,186.6 1,435.4 Wholesale Revenues: Generation Revenues (a) — — 230.2 274.6 — 15.1 162.0 Transmission Revenues (b) 399.9 1,210.3 130.8 29.0 67.0 27.5 111.2 Total Wholesale Revenues 399.9 1,210.3 361.0 303.6 67.0 42.6 273.2 Other Revenues from Contracts with Customers (c) 48.2 22.4 59.5 85.0 109.5 34.7 26.7 Total Revenues from Contracts with Customers 1,528.0 1,232.7 2,809.2 2,236.0 2,665.0 1,263.9 1,735.3 Other Revenues: Alternative Revenues (d) 3.4 (87.0) (13.0) 5.8 66.6 2.2 3.2 Other Revenues (d) 87.5 — — — 17.5 — — Total Other Revenues 90.9 (87.0) (13.0) 5.8 84.1 2.2 3.2 Total Revenues $ 1,618.9 $ 1,145.7 $ 2,796.2 $ 2,241.8 $ 2,749.1 $ 1,266.1 $ 1,738.5 (a) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $112 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 $952 million. The remaining affiliated amounts were immaterial. (c) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $69 million primarily relating to barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial. (d) Amounts include affiliated and nonaffiliated revenues. 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 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 barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial. (e) Amounts include affiliated and nonaffiliated revenues.
Fixed Performance Obligations	Company 2021 2022-2023 2024-2025 After 2025 Total (in millions) AEP $ 1,122.9 $ 164.1 $ 162.2 $ 161.5 $ 1,610.7 AEP Texas 465.4 — — — 465.4 AEPTCo 1,319.5 — — — 1,319.5 APCo 173.4 32.3 23.2 11.6 240.5 I&M 35.1 8.8 8.8 4.5 57.2 OPCo 68.1 — — 0.1 68.2 PSO 14.8 — — — 14.8 SWEPCo 41.6 — — — 41.6
Affiliated Accounts Receivable Contracts with Customers	Years Ended December 31, Company 2020 2019 (in millions) AEPTCo $ 81.0 $ 65.9 APCo 52.7 47.3 I&M 34.8 37.1 OPCo 45.9 33.9 PSO 7.8 9.7 SWEPCo 11.2 17.6

Goodwill (Tables)

Goodwill (Tables)	12 Months Ended
	Dec. 31, 2020
Changes in Carrying Amount of Goodwill	Corporate and Other Generation AEP Consolidated (in millions) 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 Impairment Losses — — — Balance as of December 31, 2020 $ 37.1 $ 15.4 $ 52.5

Subsequent Events (Tables)

Subsequent Events (Tables)	12 Months Ended
	Dec. 31, 2020
Total Estimated February 2021 Storm Restoration Expenditures	Total Estimated February 2021 (in millions) APCo $65.0 - $75.0 KPCo $75.0 - $95.0 SWEPCo $30.0 - $40.0
Preliminary Estimates of Natural Gas Expenses and Purchases of Electricity Due to February 2021 Severe Winter Weather	PSO SWEPCo (in millions) Estimated Natural Gas Expenses $ 175.0 $ 375.0 Estimated Electricity Purchases 650.0 — $ 825.0 $ 375.0

Organization and Summary of S_4

Organization and Summary of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Materials and Supplies		$ 680.6	$ 640.7
Supplementary Information
Depreciation and Amortization of Property, Plant and Equipment		2,487.5	2,203.7	$ 1,965
Amortization of Certain Securitized Assets		171.3	280.7	287.9
Amortization of Regulatory Assets and Liabilities		24	30.1	33.7
Total Depreciation and Amortization		2,682.8	2,514.5	2,286.6
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period		246.8
Restricted Cash		45.6	185.8
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		438.3	432.6	444.1	$ 412.6
Amounts Attributable to AEP Common Shareholders
Net Income (Loss) Attributable to Noncontrolling Interests		(3.4)	(1.3)	7.5
Net Income (Loss)		$ 2,200.1	$ 1,921.1	$ 1,923.8
Weighted Average Number of Basic AEP Common Shares Outstanding		495,718,223	493,694,345	492,774,600
Earnings Per Share, Basic		$ 4.44	$ 3.89	$ 3.90
Weighted Average Dilutive Effect of:
Weighted Average Number of Diluted AEP Common Shares Outstanding		497,226,867	495,306,238	493,758,277
Earnings Per Share, Diluted		$ 4.42	$ 3.88	$ 3.90
Revenues
TOTAL REVENUES		$ 14,918.5	$ 15,561.4	$ 16,195.7
Expenses
Depreciation and Amortization		2,682.8	2,514.5	2,286.6
TOTAL EXPENSES		11,930.8	12,969.1	13,513
OPERATING INCOME (LOSS)		2,987.7	2,592.3	2,682.7
Other Income (Expense)
Allowance for Equity Funds Used During Construction		148.1	168.4	132.5
Interest Expense		(1,165.7)	(1,072.5)	(984.4)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)		2,146.1	1,834.8	1,973.5
Income Tax Expense (Benefit)		40.5	(12.9)	115.3
Net Income (Loss)		2,196.7	1,919.8	1,931.3
Accounts Receivable:
Customers		613.6	625.3
Total Accounts Receivable		1,842.7	1,705.1
Accrued Tax Benefits		185.3	85.8
TOTAL CURRENT ASSETS		4,351.5	4,077.8
Property, Plant and Equipment
Transmission		27,886.7	24,808.6
Other Property, Plant and Equipment		5,294.6	4,811.5
Construction Work in Progress		4,025.7	4,319.8
Total Property, Plant and Equipment		84,313	79,145.7
Accumulated Depreciation and Amortization		20,411.4	19,007.6
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		63,901.6	60,138.1
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS		12,504.1	11,676.4
TOTAL ASSETS		80,757.2	75,892.3	68,802.8
Current Liabilities
Accounts Payable		1,709.7	2,085.8
Accrued Taxes		1,476.4	1,357.8
TOTAL CURRENT LIABILITIES		9,926.7	10,299.1
Liabilities, Noncurrent
Deferred Income Taxes		8,240.9	7,588.2
Regulatory Liabilities and Deferred Investment Tax Credits		8,378.7	8,457.6
TOTAL NONCURRENT LIABILITIES		50,010.8	45,571.4
TOTAL LIABILITIES		59,937.5	55,870.5
Equity [Abstract]
Retained Earnings		10,687.8	9,900.9
TOTAL LIABILITIES AND EQUITY		80,757.2	75,892.3
Operating Activites
Net Income (Loss)		2,196.7	1,919.8	1,931.3
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization		2,682.8	2,514.5	2,286.6
Deferred Income Taxes		196.1	(17.8)	104.3
Allowance for Equity Funds Used During Construction		(148.1)	(168.4)	(132.5)
Amortization of Deferred Property Taxes		(43.3)	(73.8)	(59.1)
Change in Other Noncurrent Assets		(142.5)	(112.8)	(172.1)
Increase (Decrease) in Other Noncurrent Liabilities		(54.5)	(116.1)	129
Accounts Receivable, Net		(129.3)	247.8	145.9
Accounts Payable		(35.3)	5.8	36.6
Accrued Taxes, Net		20.1	138.9	153.2
Net Cash Flows from Operating Activities		3,832.9	4,270.1	5,223.2
Investing Activities
Net Cash Flows Used for Investing Activities		(6,233.9)	(7,144.5)	(6,353.6)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from Financing Activities		2,406.7	2,862.9	1,161.9
Cash and Cash Equivalents at Beginning of Period		246.8
Cash and Cash Equivalents at End of Period		392.7	246.8
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts		1,029.1	1,022.5	939.3
Income Taxes		(49.1)	6.1	(24.7)
Noncash Investing and Financing Activities:
Noncash Acquisition Under Finance Leases		44.2	87.5	55.6
Construction in Progress Expenditures Incurred but Not yet Paid		975.4	1,341.1	1,120.4
Construction Expenditures Included in Current Liabilities as of December 31,		975.4	1,341.1	1,120.4
Construction Expenditures Included in Noncurrent Liabilities as of December 31,		5.5	0	0
Acquisition of Nuclear Fuel Included in Current Liabilities as of December 31,		33.4	0.1	4
Noncash Contribution of Assets by Noncontrolling Interest		0	0	84
Expected Reimbursement For Spent Nuclear Fuel Dry Cask Storage		2.6	0.3	2.2
Liabilities Assumed with Sempra Renewable LLC and Santa Rita East Acquisition		0	32.4	0
Forward Equity Purchase Contract included in Current and Noncurrent liabilities		(86.2)	(7.6)	23.1
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt		5,626.1	4,536.6	4,945.7
Repayments of Long-term Debt		1,339.8	1,220.8	2,782
Equity Method Investment		1,406.3	1,356.6
Income (Loss) from Equity Method Investment		$ 91.1	$ 72.1	$ 73.1
Antidilutive Shares Outstanding		128,000	0	0
Net Income (Loss)		$ 2,196.7	$ 1,919.8	$ 1,931.3
Retained Earnings		$ 10,687.8	9,900.9
Employees Participating in Voluntary Retirement Incentive Program		200
Percent of Voluntary Retirement Incentive Program Expense Related to AEP Service Corporation		92.00%
Lump Sum Salary Payments and Cash Subsidies
Organization and Summary of Significant Accounting Policies (Textuals)
Voluntary Retirement Incentive Program Expense		$ 13
Incremental Long-Term Incentive Plan Grants
Organization and Summary of Significant Accounting Policies (Textuals)
Voluntary Retirement Incentive Program Expense		5
Retained Earnings [Member]
Amounts Attributable to AEP Common Shareholders
Net Income (Loss)		2,200.1	1,921.1	1,923.8
Noncash Investing and Financing Activities:
Forward Equity Purchase Contract included in Current and Noncurrent liabilities		$ 110.6	47.3	0
Berkshire Hathaway [Member]
Organization and Summary of Significant Accounting Policies (Textuals)
Equity Method Investment, Ownership Percentage		50.00%
AEP Transmission Holdco [Member]
Organization and Summary of Significant Accounting Policies (Textuals)
Equity Method Investment, Ownership Percentage		50.00%
Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		25.00%
Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		59.00%
Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation		15.00%
Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		1.00%
Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		2.00%
Pension and Other Postretirement Benefit Plans [Member]
Supplementary Information
Securities Loaned		$ 177	246
AEP Texas Inc. [Member]
Materials and Supplies		70	56.7
Supplementary Information
Depreciation and Amortization of Property, Plant and Equipment		364.2	365.9	262.2
Amortization of Certain Securitized Assets		171.3	258.7	240
Amortization of Regulatory Assets and Liabilities		(5.7)	(2.3)	(2.6)
Total Depreciation and Amortization		529.8	622.3	499.6
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period		3.1
Restricted Cash		28.7	154.7
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		$ 28.8	$ 157.8	$ 159.8	157.2
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk		10.00%	10.00%	10.00%
Revenues
TOTAL REVENUES		$ 1,618.9	$ 1,709.3	$ 1,595.3
Expenses
Depreciation and Amortization		529.8	622.3	499.6
TOTAL EXPENSES		1,249.3	1,477.3	1,249
OPERATING INCOME (LOSS)		369.6	232	346.3
Other Income (Expense)
Allowance for Equity Funds Used During Construction		19.4	15.2	20
Interest Expense		(171.8)	(137.2)	(147.3)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)		229.8	124.7	232.1
Income Tax Expense (Benefit)		(11.2)	(53.6)	20.8
Net Income (Loss)		241	178.3	211.3
Accounts Receivable:
Customers		112.8	116
Total Accounts Receivable		183.6	193.4
Accrued Tax Benefits		16.8	66.1
TOTAL CURRENT ASSETS		310.9	692.9
Property, Plant and Equipment
Transmission		5,279.6	4,466.5
Other Property, Plant and Equipment		868.4	805.9
Construction Work in Progress		614.1	763.9
Total Property, Plant and Equipment		11,342.9	10,603.2
Accumulated Depreciation and Amortization		1,529.3	1,758.1
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		9,813.6	8,845.1
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS		905.7	1,051.1
TOTAL ASSETS		11,030.2	10,589.1
Current Liabilities
Accounts Payable		231.7	256.8
Affiliated Companies		44	35.6
Accrued Taxes		78.3	84.9
TOTAL CURRENT LIABILITIES		676.8	1,027.2
Liabilities, Noncurrent
Deferred Income Taxes		1,016.7	965.4
Regulatory Liabilities and Deferred Investment Tax Credits		1,270.8	1,316.9
TOTAL NONCURRENT LIABILITIES		7,147.4	6,600.8
TOTAL LIABILITIES		7,824.2	7,628
Equity [Abstract]
Retained Earnings		1,757	1,516
TOTAL LIABILITIES AND EQUITY		11,030.2	10,589.1
Operating Activites
Net Income (Loss)		241	178.3	211.3
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization		529.8	622.3	499.6
Deferred Income Taxes		(15.2)	(23.5)	(16.5)
Allowance for Equity Funds Used During Construction		(19.4)	(15.2)	(20)
Change in Other Noncurrent Assets		(74)	9.3	(60.3)
Increase (Decrease) in Other Noncurrent Liabilities		(24.7)	11.3	44.9
Accounts Receivable, Net		9.8	3.5	(2.9)
Accounts Payable		30.2	7.5	(20.3)
Accrued Taxes, Net		42.7	(11.8)	(5.6)
Net Cash Flows from Operating Activities		614.2	823.4	651.9
Investing Activities
Net Cash Flows Used for Investing Activities		(1,065.4)	(1,472.2)	(1,289.7)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from Financing Activities		322.2	646.8	640.4
Cash and Cash Equivalents at Beginning of Period		3.1
Cash and Cash Equivalents at End of Period		0.1	3.1
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts		153.2	148.6	145.9
Income Taxes		(42.9)	(11)	7.9
Noncash Investing and Financing Activities:
Construction in Progress Expenditures Incurred but Not yet Paid		177.8	225.5	243.1
Construction Expenditures Included in Current Liabilities as of December 31,		177.8	225.5	243.1
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt		652.7	1,070.4	494
Repayments of Long-term Debt		392.1	401.8	266.1
Net Income (Loss)		241	178.3	211.3
Retained Earnings		1,757	1,516
AEP Texas Inc. [Member] | Retained Earnings [Member]
Other Income (Expense)
Net Income (Loss)		241	178.3	211.3
Operating Activites
Net Income (Loss)		241	178.3	211.3
Organization and Summary of Significant Accounting Policies (Textuals)
Net Income (Loss)		$ 241	178.3	211.3
AEP Texas Inc. [Member] | Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		25.00%
AEP Texas Inc. [Member] | Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		59.00%
AEP Texas Inc. [Member] | Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation		15.00%
AEP Texas Inc. [Member] | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		1.00%
AEP Texas Inc. [Member] | Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
AEP Texas Inc. [Member] | Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
AEP Texas Inc. [Member] | Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		2.00%
AEP Texas Inc. [Member] | Pension and Other Postretirement Benefit Plans [Member]
Supplementary Information
Securities Loaned		$ 177	246
AEP Transmission Co [Member]
Materials and Supplies		8.5	13.8
Supplementary Information
Depreciation and Amortization of Property, Plant and Equipment		249	176	133.9
Amortization of Certain Securitized Assets		0	0	0
Amortization of Regulatory Assets and Liabilities		0	0	0
Total Depreciation and Amortization		249	176	133.9
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period		$ 0	$ 0	$ 0
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk		10.00%	10.00%	10.00%
Revenues
TOTAL REVENUES		$ 1,145.7	$ 1,021.4	$ 776.1
Expenses
Depreciation and Amortization		249	176	133.9
TOTAL EXPENSES		564.2	454.2	366
OPERATING INCOME (LOSS)		581.5	567.2	410.1
Other Income (Expense)
Allowance for Equity Funds Used During Construction		74	84.3	70.6
Interest Expense		(127.8)	(97.4)	(83.2)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)		530.1	557.1	400
Income Tax Expense (Benefit)		106.7	117.4	84.1
Net Income (Loss)		423.4	439.7	315.9
Accounts Receivable:
Customers		22.9	19
Total Accounts Receivable		104.1	85.1
Accrued Tax Benefits		9.9	9.3
TOTAL CURRENT ASSETS		235.8	197.4
Property, Plant and Equipment
Transmission		9,593.5	8,137.9
Other Property, Plant and Equipment		329.5	269.6
Construction Work in Progress		1,422.6	1,485.7
Total Property, Plant and Equipment		11,345.6	9,893.2
Accumulated Depreciation and Amortization		572.8	402.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		10,772.8	9,490.9
Other Noncurrent Assets
Deferred Property Taxes		220.1	193.5
TOTAL OTHER NONCURRENT ASSETS		237.4	202.5
TOTAL ASSETS		11,246	9,890.8	8,394.1
Current Liabilities
Accounts Payable		380.4	493.4
Affiliated Companies		97.3	71.2
Accrued Taxes		418.1	355.6
TOTAL CURRENT LIABILITIES		1,137.5	1,093.1
Liabilities, Noncurrent
Deferred Income Taxes		906.9	817.8
Regulatory Liabilities and Deferred Investment Tax Credits		581.8	540.9
TOTAL NONCURRENT LIABILITIES		5,395.6	4,788.2
TOTAL LIABILITIES		6,533.1	5,881.3
Equity [Abstract]
Retained Earnings		1,947.3	1,528.9
TOTAL MEMBER'S EQUITY		4,712.9	4,009.5	3,569.8	2,589.9
TOTAL LIABILITIES AND EQUITY		11,246	9,890.8
Operating Activites
Net Income (Loss)		423.4	439.7	315.9
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization		249	176	133.9
Deferred Income Taxes		81.6	91.3	98.9
Allowance for Equity Funds Used During Construction		(74)	(84.3)	(70.6)
Amortization of Deferred Property Taxes		(26.6)	(35.6)	(32.9)
Change in Other Noncurrent Assets		(8.2)	9.6	14.6
Increase (Decrease) in Other Noncurrent Liabilities		8.3	(8.1)	17.4
Accounts Receivable, Net		(19)	(5.4)	36.7
Accounts Payable		77.8	37.6	(7.5)
Accrued Taxes, Net		62.7	90.8	73.4
Net Cash Flows from Operating Activities		771.2	708.6	548.6
Investing Activities
Net Cash Flows Used for Investing Activities		(1,640.4)	(1,403.2)	(1,513.3)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from Financing Activities		869.2	694.6	964.7
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
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts		119.7	90.6	80.2
Income Taxes		22.9	1.5	(30.7)
Noncash Investing and Financing Activities:
Construction in Progress Expenditures Incurred but Not yet Paid		311.9	472.7	345
Construction Expenditures Included in Current Liabilities as of December 31,		311.9	472.7	345
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt		519.5	688	321
Repayments of Long-term Debt		0	85	50
Net Income (Loss)		423.4	439.7	315.9
Retained Earnings		1,947.3	1,528.9
AEP Transmission Co [Member] | Retained Earnings [Member]
Other Income (Expense)
Net Income (Loss)		423.4	439.7	315.9
Equity [Abstract]
TOTAL MEMBER'S EQUITY		1,947.3	1,528.9	1,089.2	773.3
Operating Activites
Net Income (Loss)		423.4	439.7	315.9
Organization and Summary of Significant Accounting Policies (Textuals)
Net Income (Loss)		423.4	439.7	315.9
Appalachian Power Co [Member]
Materials and Supplies		99.6	105.2
Supplementary Information
Depreciation and Amortization of Property, Plant and Equipment		507.8	466.5	428.1
Amortization of Certain Securitized Assets		0	0	0
Amortization of Regulatory Assets and Liabilities		(0.3)	0.3	0.3
Total Depreciation and Amortization		507.5	466.8	428.4
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period		3.3
Restricted Cash		16.9	23.5
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		$ 22.7	$ 26.8	$ 29.8	19.2
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk		10.00%	10.00%	10.00%
Revenues
TOTAL REVENUES		$ 2,796.2	$ 2,924.7	$ 2,967.5
Expenses
Depreciation and Amortization		507.5	466.8	428.4
TOTAL EXPENSES		2,239.6	2,527.4	2,484
OPERATING INCOME (LOSS)		556.6	397.3	483.5
Other Income (Expense)
Allowance for Equity Funds Used During Construction		14.6	16.6	13.2
Interest Expense		(217.6)	(205)	(194.8)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)		374	228.3	322.9
Income Tax Expense (Benefit)		4.3	(78)	(44.9)
Net Income (Loss)		369.7	306.3	367.8
Accounts Receivable:
Customers		142.8	129
Total Accounts Receivable		284.4	250.9
TOTAL CURRENT ASSETS		674.1	700.6
Property, Plant and Equipment
Transmission		3,900.5	3,584.1
Other Property, Plant and Equipment		627.2	571.3
Construction Work in Progress		484.6	593.4
Total Property, Plant and Equipment		16,110.3	15,514.2
Accumulated Depreciation and Amortization		4,716.2	4,432.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		11,394.1	11,081.9
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS		1,247	985.8
TOTAL ASSETS		13,315.2	12,768.3
Current Liabilities
Accounts Payable		212	307.8
Affiliated Companies		97.1	92.5
Accrued Taxes		109.9	99.6
TOTAL CURRENT LIABILITIES		1,217.7	1,226
Liabilities, Noncurrent
Deferred Income Taxes		1,749.9	1,680.8
Regulatory Liabilities and Deferred Investment Tax Credits		1,224.7	1,268.7
TOTAL NONCURRENT LIABILITIES		7,753.2	7,369.9
TOTAL LIABILITIES		8,970.9	8,595.9
Equity [Abstract]
Retained Earnings		2,248	2,078.3
TOTAL LIABILITIES AND EQUITY		13,315.2	12,768.3
Operating Activites
Net Income (Loss)		369.7	306.3	367.8
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization		507.5	466.8	428.4
Deferred Income Taxes		(26.2)	(126.2)	(16.8)
Allowance for Equity Funds Used During Construction		(14.6)	(16.6)	(13.2)
Change in Other Noncurrent Assets		(40.4)	(38.2)	58.1
Increase (Decrease) in Other Noncurrent Liabilities		11.2	(40.3)	(4.8)
Accounts Receivable, Net		(30.2)	35.7	33.6
Accounts Payable		(48.1)	37.7	(13.3)
Accrued Taxes, Net		31.3	(10.2)	(13.2)
Net Cash Flows from Operating Activities		712	661.4	846.6
Investing Activities
Net Cash Flows Used for Investing Activities		(757.9)	(837.4)	(769.4)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from Financing Activities		41.8	173	(66.6)
Cash and Cash Equivalents at Beginning of Period		3.3
Cash and Cash Equivalents at End of Period		5.8	3.3
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts		207.1	190.7	182
Income Taxes		0	63	(13)
Noncash Investing and Financing Activities:
Construction in Progress Expenditures Incurred but Not yet Paid		105.6	149.7	134.4
Construction Expenditures Included in Current Liabilities as of December 31,		105.6	149.7	134.4
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt		606.9	478.2	203.2
Repayments of Long-term Debt		140.3	180.5	124
Net Income (Loss)		369.7	306.3	367.8
Retained Earnings		2,248	2,078.3
Appalachian Power Co [Member] | Retained Earnings [Member]
Other Income (Expense)
Net Income (Loss)		369.7	306.3	367.8
Operating Activites
Net Income (Loss)		369.7	306.3	367.8
Organization and Summary of Significant Accounting Policies (Textuals)
Net Income (Loss)		$ 369.7	306.3	367.8
Appalachian Power Co [Member] | Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		25.00%
Appalachian Power Co [Member] | Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		59.00%
Appalachian Power Co [Member] | Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation		15.00%
Appalachian Power Co [Member] | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		1.00%
Appalachian Power Co [Member] | Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Appalachian Power Co [Member] | Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Appalachian Power Co [Member] | Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		2.00%
Appalachian Power Co [Member] | Pension and Other Postretirement Benefit Plans [Member]
Supplementary Information
Securities Loaned		$ 177	246
Indiana Michigan Power Co [Member]
Materials and Supplies		175.8	171.3
Supplementary Information
Depreciation and Amortization of Property, Plant and Equipment		393.3	330.6	278.9
Amortization of Certain Securitized Assets		0	0	0
Amortization of Regulatory Assets and Liabilities		18.3	20	14.2
Total Depreciation and Amortization		411.6	350.6	293.1
Ohio Valley Electric Corporation - Barging and Other Transportation Services (43.47% Owned)		60.8	63.4	63.4
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period		$ 2	$ 2.4	$ 1.3
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk		10.00%	10.00%	10.00%
Revenues
TOTAL REVENUES		$ 2,241.8	$ 2,306.7	$ 2,370.7
Expenses
Depreciation and Amortization		411.6	350.6	293.1
TOTAL EXPENSES		1,878.9	1,965.9	1,993.5
OPERATING INCOME (LOSS)		362.9	340.8	377.2
Other Income (Expense)
Allowance for Equity Funds Used During Construction		11.5	19.4	11.9
Interest Expense		(112.3)	(117.9)	(124.1)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)		277.3	258.8	290.4
Income Tax Expense (Benefit)		(7.5)	(10.6)	29.1
Net Income (Loss)		284.8	269.4	261.3
Accounts Receivable:
Customers		44	53.6
Total Accounts Receivable		97	109.5
Accrued Tax Benefits		10.3	0
TOTAL CURRENT ASSETS		418.8	403
Property, Plant and Equipment
Transmission		1,696.4	1,641.8
Other Property, Plant and Equipment		686.7	632.6
Construction Work in Progress		362.4	382.3
Total Property, Plant and Equipment		10,604.8	10,194
Accumulated Depreciation and Amortization		3,552.5	3,294.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		7,052.3	6,899.7
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS		4,167.2	3,934.7
TOTAL ASSETS		11,638.3	11,237.4
Current Liabilities
Accounts Payable		153.2	169.4
Affiliated Companies		80.5	68.4
Accrued Taxes		102.5	112.4
TOTAL CURRENT LIABILITIES		1,104.5	883.4
Liabilities, Noncurrent
Deferred Income Taxes		1,064.4	979.7
Regulatory Liabilities and Deferred Investment Tax Credits		2,041.9	1,891.4
TOTAL NONCURRENT LIABILITIES		7,784.6	7,809.6
TOTAL LIABILITIES		8,889.1	8,693
Equity [Abstract]
Retained Earnings		1,718.7	1,518.5
TOTAL LIABILITIES AND EQUITY		11,638.3	11,237.4
Operating Activites
Net Income (Loss)		284.8	269.4	261.3
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization		411.6	350.6	293.1
Deferred Income Taxes		(16.2)	(52.7)	(42.9)
Allowance for Equity Funds Used During Construction		(11.5)	(19.4)	(11.9)
Change in Other Noncurrent Assets		6.1	8.3	(36.5)
Increase (Decrease) in Other Noncurrent Liabilities		45	33.7	72.1
Accounts Receivable, Net		14.5	35.4	4.8
Accounts Payable		(10.8)	3.6	(14.1)
Accrued Taxes, Net		(20.2)	48.3	41.2
Net Cash Flows from Operating Activities		776.3	685.2	725.7
Investing Activities
Net Cash Flows Used for Investing Activities		(648.9)	(720.1)	(654.8)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from Financing Activities		(126.1)	34.5	(69.8)
Net Increase (Decrease) in Cash and Cash Equivalents		1.3	(0.4)	1.1
Cash and Cash Equivalents at Beginning of Period		2	2.4	1.3
Cash and Cash Equivalents at End of Period		3.3	2	2.4
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts		107.6	111.9	116.9
Income Taxes		42.1	3.4	32.6
Noncash Investing and Financing Activities:
Construction in Progress Expenditures Incurred but Not yet Paid		62.8	86	93
Construction Expenditures Included in Current Liabilities as of December 31,		62.8	86	93
Acquisition of Nuclear Fuel Included in Current Liabilities as of December 31,		33.4	0.1	4
Expected Reimbursement For Spent Nuclear Fuel Dry Cask Storage		2.6	0.3	2.2
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt		69.5	123.3	1,168.1
Repayments of Long-term Debt		93.2	117.1	884.9
Net Income (Loss)		284.8	269.4	261.3
Retained Earnings		1,718.7	1,518.5
Indiana Michigan Power Co [Member] | Retained Earnings [Member]
Other Income (Expense)
Net Income (Loss)		284.8	269.4	261.3
Operating Activites
Net Income (Loss)		284.8	269.4	261.3
Organization and Summary of Significant Accounting Policies (Textuals)
Net Income (Loss)		$ 284.8	269.4	261.3
Indiana Michigan Power Co [Member] | Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		25.00%
Indiana Michigan Power Co [Member] | Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		59.00%
Indiana Michigan Power Co [Member] | Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation		15.00%
Indiana Michigan Power Co [Member] | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		1.00%
Indiana Michigan Power Co [Member] | Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Indiana Michigan Power Co [Member] | Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Indiana Michigan Power Co [Member] | Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		2.00%
Indiana Michigan Power Co [Member] | Pension and Other Postretirement Benefit Plans [Member]
Supplementary Information
Securities Loaned		$ 177	246
Ohio Power Co [Member]
Materials and Supplies		66.9	52.3
Supplementary Information
Depreciation and Amortization of Property, Plant and Equipment		275	229.4	232.6
Amortization of Certain Securitized Assets		0	22	47.9
Amortization of Regulatory Assets and Liabilities		1.6	(10.5)	(20.8)
Total Depreciation and Amortization		276.6	240.9	259.7
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period		3.7
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		$ 7.4	$ 3.7	$ 32.5	$ 29.7
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk		10.00%	10.00%	10.00%
Revenues
TOTAL REVENUES		$ 2,749.1	$ 2,797.6	$ 3,063.4
Expenses
Depreciation and Amortization		276.6	240.9	259.7
TOTAL EXPENSES		2,345.4	2,396.4	2,643.6
OPERATING INCOME (LOSS)		403.7	401.2	419.8
Other Income (Expense)
Allowance for Equity Funds Used During Construction		12.5	18.2	9.8
Interest Expense		(117.2)	(106.2)	(100.7)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)		316.6	332	349.5
Income Tax Expense (Benefit)		45.2	34.9	24
Net Income (Loss)		271.4	297.1	325.5
Accounts Receivable:
Customers		50	53
Total Accounts Receivable		133.2	132.4
TOTAL CURRENT ASSETS		256.3	238.5
Property, Plant and Equipment
Transmission		2,831.9	2,686.3
Other Property, Plant and Equipment		899.6	765.8
Construction Work in Progress		362.3	394.4
Total Property, Plant and Equipment		9,802.1	9,170
Accumulated Depreciation and Amortization		2,350	2,263
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		7,452.1	6,907
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS		1,002	898.1
TOTAL ASSETS		8,710.4	8,043.6
Current Liabilities
Accounts Payable		181	233.7
Affiliated Companies		118.4	103.6
Accrued Taxes		631	587.9
TOTAL CURRENT LIABILITIES		1,906.2	1,297.9
Liabilities, Noncurrent
Deferred Income Taxes		955.1	849.4
Regulatory Liabilities and Deferred Investment Tax Credits		1,005.2	1,090.9
TOTAL NONCURRENT LIABILITIES		4,111.5	4,237.2
TOTAL LIABILITIES		6,017.7	5,535.1
Equity [Abstract]
Retained Earnings		1,532.7	1,348.5
TOTAL LIABILITIES AND EQUITY		8,710.4	8,043.6
Operating Activites
Net Income (Loss)		271.4	297.1	325.5
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization		276.6	240.9	259.7
Deferred Income Taxes		77.2	43.8	(36.2)
Allowance for Equity Funds Used During Construction		(12.5)	(18.2)	(9.8)
Amortization of Deferred Property Taxes		(16.6)	(33.7)	(12.5)
Change in Other Noncurrent Assets		(49.4)	(35.3)	(11.5)
Increase (Decrease) in Other Noncurrent Liabilities		(66.4)	(93.2)	53.8
Accounts Receivable, Net		4.2	75	43.1
Accounts Payable		10.3	0.4	(13.8)
Accrued Taxes, Net		43.3	38.7	26.8
Net Cash Flows from Operating Activities		410.9	421.2	1,028.7
Investing Activities
Net Cash Flows Used for Investing Activities		(791)	(744.1)	(707.5)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from Financing Activities		383.8	294.1	(318.4)
Cash and Cash Equivalents at Beginning of Period		3.7
Cash and Cash Equivalents at End of Period		7.4	3.7
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts		111.2	100.6	97.1
Income Taxes		(26.9)	7.3	51.3
Noncash Investing and Financing Activities:
Construction in Progress Expenditures Incurred but Not yet Paid		76.7	125.9	98.2
Construction Expenditures Included in Current Liabilities as of December 31,		76.7	125.9	98.2
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt		347	444.3	392.8
Repayments of Long-term Debt		0.1	80.3	397.1
Net Income (Loss)		271.4	297.1	325.5
Retained Earnings		1,532.7	1,348.5
Ohio Power Co [Member] | Retained Earnings [Member]
Other Income (Expense)
Net Income (Loss)		271.4	297.1	325.5
Operating Activites
Net Income (Loss)		271.4	297.1	325.5
Organization and Summary of Significant Accounting Policies (Textuals)
Net Income (Loss)		$ 271.4	297.1	325.5
Ohio Power Co [Member] | Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		25.00%
Ohio Power Co [Member] | Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		59.00%
Ohio Power Co [Member] | Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation		15.00%
Ohio Power Co [Member] | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		1.00%
Ohio Power Co [Member] | Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Ohio Power Co [Member] | Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Ohio Power Co [Member] | Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		2.00%
Ohio Power Co [Member] | Pension and Other Postretirement Benefit Plans [Member]
Supplementary Information
Securities Loaned		$ 177	246
Public Service Co Of Oklahoma [Member]
Materials and Supplies		54	46.8
Supplementary Information
Depreciation and Amortization of Property, Plant and Equipment		171.9	162.5	155.5
Amortization of Certain Securitized Assets		0	0	0
Amortization of Regulatory Assets and Liabilities		1.6	7	8.5
Total Depreciation and Amortization		173.5	169.5	164
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period		$ 1.5	$ 2	$ 1.6
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk		10.00%	10.00%	10.00%
Revenues
TOTAL REVENUES		$ 1,266.1	$ 1,481.8	$ 1,547.3
Expenses
Depreciation and Amortization		173.5	169.5	164
TOTAL EXPENSES		1,090.2	1,282.5	1,404.8
OPERATING INCOME (LOSS)		175.9	199.3	142.5
Other Income (Expense)
Allowance for Equity Funds Used During Construction		4	2.7	0.4
Interest Expense		(60.3)	(66.5)	(63.5)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)		128.2	145.1	88.2
Income Tax Expense (Benefit)		5.2	7.5	5
Net Income (Loss)		123	137.6	83.2
Accounts Receivable:
Customers		30.8	28.9
Total Accounts Receivable		48.4	49.8
Accrued Tax Benefits		10.9	11.3
TOTAL CURRENT ASSETS		181.3	188.2
Property, Plant and Equipment
Transmission		1,069.9	948.5
Other Property, Plant and Equipment		393.3	342.1
Construction Work in Progress		128.7	133.4
Total Property, Plant and Equipment		5,925.6	5,683.4
Accumulated Depreciation and Amortization		1,605.6	1,580.1
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		4,320	4,103.3
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS		489.4	460
TOTAL ASSETS		4,990.7	4,751.5
Current Liabilities
Accounts Payable		107	134.3
Affiliated Companies		43.4	59.3
Accrued Taxes		26.8	22.9
TOTAL CURRENT LIABILITIES		478.6	445.8
Liabilities, Noncurrent
Deferred Income Taxes		688.5	628.3
Regulatory Liabilities and Deferred Investment Tax Credits		802.2	837.2
TOTAL NONCURRENT LIABILITIES		2,966.5	2,932.4
TOTAL LIABILITIES		3,445.1	3,378.2
Equity [Abstract]
Retained Earnings		974.3	851
TOTAL LIABILITIES AND EQUITY		4,990.7	4,751.5
Operating Activites
Net Income (Loss)		123	137.6	83.2
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization		173.5	169.5	164
Deferred Income Taxes		17	(18.2)	(31.1)
Allowance for Equity Funds Used During Construction		(4)	(2.7)	(0.4)
Change in Other Noncurrent Assets		(17.9)	5.7	0
Increase (Decrease) in Other Noncurrent Liabilities		1.6	(7.3)	21.4
Accounts Receivable, Net		1.4	15.4	5.1
Accounts Payable		(29.5)	7	17.7
Accrued Taxes, Net		3.6	3.9	13.2
Net Cash Flows from Operating Activities		157	350.3	330.5
Investing Activities
Net Cash Flows Used for Investing Activities		(295.1)	(328.1)	(233)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from Financing Activities		139.2	(22.7)	(97.1)
Net Increase (Decrease) in Cash and Cash Equivalents		1.1	(0.5)	0.4
Cash and Cash Equivalents at Beginning of Period		1.5	2	1.6
Cash and Cash Equivalents at End of Period		2.6	1.5	2
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts		59.1	61.1	62
Income Taxes		(11.8)	22.4	17.9
Noncash Investing and Financing Activities:
Construction in Progress Expenditures Incurred but Not yet Paid		35.5	46	33.2
Construction Expenditures Included in Current Liabilities as of December 31,		35.5	46	33.2
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt		0	349.5	0
Repayments of Long-term Debt		13.2	250.5	0.5
Net Income (Loss)		123	137.6	83.2
Retained Earnings		974.3	851
Public Service Co Of Oklahoma [Member] | Retained Earnings [Member]
Other Income (Expense)
Net Income (Loss)		123	137.6	83.2
Operating Activites
Net Income (Loss)		123	137.6	83.2
Organization and Summary of Significant Accounting Policies (Textuals)
Net Income (Loss)		$ 123	137.6	83.2
Public Service Co Of Oklahoma [Member] | Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		25.00%
Public Service Co Of Oklahoma [Member] | Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		59.00%
Public Service Co Of Oklahoma [Member] | Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation		15.00%
Public Service Co Of Oklahoma [Member] | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		1.00%
Public Service Co Of Oklahoma [Member] | Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Public Service Co Of Oklahoma [Member] | Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Public Service Co Of Oklahoma [Member] | Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		2.00%
Public Service Co Of Oklahoma [Member] | Pension and Other Postretirement Benefit Plans [Member]
Supplementary Information
Securities Loaned		$ 177	246
Southwestern Electric Power Co [Member]
Materials and Supplies		95.8	94
Supplementary Information
Depreciation and Amortization of Property, Plant and Equipment		271.2	247.9	237
Amortization of Certain Securitized Assets		0	0	0
Amortization of Regulatory Assets and Liabilities		1.5	1.2	2.5
Total Depreciation and Amortization		272.7	249.1	239.5
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period		$ 1.6	$ 24.5	$ 1.6
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		$ 2.9	$ 3.6	$ 5
Net Income (Loss)		180.8	158.6	147.2
Revenues
TOTAL REVENUES		1,738.5	1,750.9	1,821.9
Expenses
Depreciation and Amortization		272.7	249.1	239.5
TOTAL EXPENSES		1,448	1,495.2	1,544.2
OPERATING INCOME (LOSS)		290.5	255.7	277.7
Other Income (Expense)
Allowance for Equity Funds Used During Construction		7.7	6.8	6
Interest Expense		(118.5)	(119.1)	(127.9)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS (LOSS)		190.2	154.5	169.9
Income Tax Expense (Benefit)		9.4	(4.7)	20.4
Net Income (Loss)		183.7	162.2	152.2
Accounts Receivable:
Customers		27.1	29
Total Accounts Receivable		64.9	75.3
Accrued Tax Benefits		29.9	7.6
TOTAL CURRENT ASSETS		428	354.1
Property, Plant and Equipment
Transmission		2,165.7	2,056.5
Other Property, Plant and Equipment		788.8	733.4
Construction Work in Progress		228.3	216.9
Total Property, Plant and Equipment		10,246.7	9,968.9
Accumulated Depreciation and Amortization		3,158.5	2,873.7
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		7,088.2	7,095.2
Other Noncurrent Assets
TOTAL OTHER NONCURRENT ASSETS		637.9	382.9
TOTAL ASSETS		8,154.1	7,832.2
Current Liabilities
Accounts Payable		135.9	138
Affiliated Companies		43	53.6
Accrued Taxes		41	41.8
TOTAL CURRENT LIABILITIES		763.6	674.7
Liabilities, Noncurrent
Deferred Income Taxes		1,017.6	940.9
Regulatory Liabilities and Deferred Investment Tax Credits		863.4	892.3
TOTAL NONCURRENT LIABILITIES		4,762.8	4,716.4
TOTAL LIABILITIES		5,526.4	5,391.1
Equity [Abstract]
Retained Earnings		1,811.9	1,629.5
TOTAL LIABILITIES AND EQUITY		8,154.1	7,832.2
Operating Activites
Net Income (Loss)		183.7	162.2	152.2
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization		272.7	249.1	239.5
Deferred Income Taxes		32.4	(11)	1.2
Allowance for Equity Funds Used During Construction		(7.7)	(6.8)	(6)
Change in Other Noncurrent Assets		16.1	2.7	(18.1)
Increase (Decrease) in Other Noncurrent Liabilities		25.2	2.7	42.8
Accounts Receivable, Net		7.3	0	53.5
Accounts Payable		11.1	(28.4)	0.9
Accrued Taxes, Net		(23.1)	(3.2)	2.3
Net Cash Flows from Operating Activities		356.3	339.8	504.8
Investing Activities
Net Cash Flows Used for Investing Activities		(392.6)	(330.2)	(528.9)
Net Cash Provided by (Used in) Financing Activities
Net Cash Flows from Financing Activities		47.9	(32.5)	47
Net Increase (Decrease) in Cash and Cash Equivalents		11.6	(22.9)	22.9
Cash and Cash Equivalents at Beginning of Period		1.6	24.5	1.6
Cash and Cash Equivalents at End of Period		13.2	1.6	24.5
Cash Paid (Received) for:
Cash Paid for Interest, Net of Capitalized Amounts		110.7	111.1	125.7
Income Taxes		4.3	8.6	18.8
Noncash Investing and Financing Activities:
Construction in Progress Expenditures Incurred but Not yet Paid		46	69.1	42
Construction Expenditures Included in Current Liabilities as of December 31,		46	69.1	42
Organization and Summary of Significant Accounting Policies (Textuals)
Issuance of Long-term Debt		0	0	1,065.7
Repayments of Long-term Debt		21.2	59.7	794.5
Income (Loss) from Equity Method Investment		2.9	3	2.7
Net Income (Loss)		183.7	162.2	152.2
Retained Earnings		1,811.9	1,629.5
Southwestern Electric Power Co [Member] | Retained Earnings [Member]
Amounts Attributable to AEP Common Shareholders
Net Income (Loss)		$ 180.8	158.6	$ 147.2
Southwestern Electric Power Co [Member] | Pension Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		25.00%
Southwestern Electric Power Co [Member] | Pension Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		59.00%
Southwestern Electric Power Co [Member] | Pension Plans [Member] | Other Investments [Member]
Target Asset Allocations
Target Asset Allocation		15.00%
Southwestern Electric Power Co [Member] | Pension Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		1.00%
Southwestern Electric Power Co [Member] | Other Postretirement Benefit Plans [Member] | Equity [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Southwestern Electric Power Co [Member] | Other Postretirement Benefit Plans [Member] | Fixed Income [Member]
Target Asset Allocations
Target Asset Allocation		49.00%
Southwestern Electric Power Co [Member] | Other Postretirement Benefit Plans [Member] | Cash and Cash Equivalents [Member]
Target Asset Allocations
Target Asset Allocation		2.00%
Southwestern Electric Power Co [Member] | Pension and Other Postretirement Benefit Plans [Member]
Supplementary Information
Securities Loaned		$ 177	$ 246
Restricted Stock Units and Performance Share Units [Member]
Weighted Average Dilutive Effect of:
Weighted Average Dilutive Effect of Shares		1,500,000	1,600,000	1,000,000
Dilutive Securities, Effect on Basic Earnings Per Share		$ (0.02)	$ (0.01)	$ 0
Revenues [Member] | AEP Texas Inc. [Member]
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk	[1]	46.00%	48.00%	45.00%
Revenues [Member] | AEP Transmission Co [Member]
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk		78.00%	79.00%	77.00%
Accounts Receivable [Member] | AEP Texas Inc. [Member]
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk	[1]	40.00%	43.00%	35.00%
Accounts Receivable [Member] | AEP Transmission Co [Member]
Risks and Uncertainties
Percentage of Significant Customers Concentration Risk		78.00%	78.00%	84.00%
Noncontrolling Interest [Member] | Sempra Renewables LLC and Santa Rita East Acquisition [Member]
Noncash Investing and Financing Activities:
Noncash Contribution of Assets by Noncontrolling Interest		$ 0	$ 253.4	$ 0
Sabine Mining Co [Member] | Southwestern Electric Power Co [Member]
Materials and Supplies		23.3	23.1
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents at Beginning of Period		0
Property, Plant and Equipment
Other Property, Plant and Equipment		223.7	212.3
Accumulated Depreciation and Amortization		126.5	107.5
Net Cash Provided by (Used in) Financing Activities
Cash and Cash Equivalents at Beginning of Period		0
Cash and Cash Equivalents at End of Period		$ 10.1	$ 0
[1]	In January 2021, NRG Energy, parent company of Reliant Energy, completed a deal to purchase Direct Energy from Centrica.

Comprehensive Income (Details)

Comprehensive Income (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		$ (147.7)		$ (120.4)		$ (67.8)
Change in Fair Value Recognized in AOCI		(66.4)		(69.7)		6.6
Commodity
Generation and Marketing Revenues		14,918.5		15,561.4		16,195.7
Interest Rate
Interest Expense		1,165.7		1,072.5		984.4
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		163.2		53.7		(38.3)
Income Tax (Expense) Benefit		40.5		(12.9)		115.3
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		129		42.4		(30.3)
Net Current Period Other Comprehensive Income (Loss)		62.6		(27.3)		(23.7)
ASU 2018-02 Adoption						(3)
ASU 2016-01 Adoption						0
Ending Balance in AOCI		(85.1)		(147.7)		(120.4)
Securities Available for Sale [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI				0		11.9
Change in Fair Value Recognized in AOCI						0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit						0
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit						0
Net Current Period Other Comprehensive Income (Loss)						0
ASU 2018-02 Adoption						0
ASU 2016-01 Adoption						(11.9)
Ending Balance in AOCI						0
Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		130.7		136.3		141.6
Change in Fair Value Recognized in AOCI		0		0		0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		(8.9)		(7.1)		(6.7)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		(7)		(5.6)		(5.3)
Net Current Period Other Comprehensive Income (Loss)		(7)		(5.6)		(5.3)
ASU 2018-02 Adoption						0
ASU 2016-01 Adoption						0
Ending Balance in AOCI		123.7		130.7		136.3
Pension and OPEB [Member] | Changes in Funded Status [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(163.4)		(221.1)		(179.9)
Change in Fair Value Recognized in AOCI		62.7		57.7		(33)
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)		62.7		57.7		(33)
ASU 2018-02 Adoption						(8.2)
ASU 2016-01 Adoption						0
Ending Balance in AOCI		(100.7)		(163.4)		(221.1)
Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)		62.6		(27.3)		(23.7)
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		(103.5)		(23)		(28.4)
Change in Fair Value Recognized in AOCI		(89.2)		(127.2)		37.3
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		167.2		59.3		(32.7)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		132.1		46.7		(25.8)
Net Current Period Other Comprehensive Income (Loss)		42.9		(80.5)		11.5
ASU 2018-02 Adoption						(6.1)
ASU 2016-01 Adoption						0
Ending Balance in AOCI		(60.6)		(103.5)		(23)
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)		(12.6)		(13)
Change in Fair Value Recognized in AOCI		(39.9)	[1]	(0.2)	[1]	2.3
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		4.9		1.5		1.1
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		3.9		1.3		0.8
Net Current Period Other Comprehensive Income (Loss)		(36)		1.1		3.1
ASU 2018-02 Adoption						(2.7)
ASU 2016-01 Adoption						0
Ending Balance in AOCI		(47.5)		(11.5)		(12.6)
Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Apple Blossom and Black Oak [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Change in Fair Value Recognized in AOCI		6		4
Generation and Marketing Revenues [Member]
Commodity
Generation and Marketing Revenues		1,621		1,721.8		1,818.1
Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale		2,930.4		3,165.2		3,427.1
AEP Texas Inc. [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(12.8)		(15.1)		(12.6)
Change in Fair Value Recognized in AOCI		2.7		1.1		(1)
Commodity
Generation and Marketing Revenues		1,528		1,551.6		1,493
Interest Rate
Interest Expense		171.8		137.2		147.3
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		1.5		1.5		1.6
Income Tax (Expense) Benefit		(11.2)		(53.6)		20.8
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		1.2		1.2		1.2
Net Current Period Other Comprehensive Income (Loss)		3.9		2.3		0.2
ASU 2018-02 Adoption						(0.9)
Ending Balance in AOCI		(8.9)		(12.8)		(15.1)
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		4.9		4.7		4.5
Change in Fair Value Recognized in AOCI		0		0		0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		0.2		0.2		0.3
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		0.2		0.2		0.2
Net Current Period Other Comprehensive Income (Loss)		0.2		0.2		0.2
ASU 2018-02 Adoption				0		0
Ending Balance in AOCI		5.1		4.9		4.7
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		(14.3)		(15.4)		(12.6)
Change in Fair Value Recognized in AOCI		2.6		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)		2.6		1.1		(1)
ASU 2018-02 Adoption				0		(1.8)
Ending Balance in AOCI		(11.7)		(14.3)		(15.4)
AEP Texas Inc. [Member] | Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)		3.9		2.3		0.2
ASU 2018-02 Adoption				0		(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		(3.4)		(4.4)		(4.5)
Change in Fair Value Recognized in AOCI		0.1		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		1
Net Current Period Other Comprehensive Income (Loss)		1.1		1		1
ASU 2018-02 Adoption				0		(0.9)
Ending Balance in AOCI		(2.3)		(3.4)		(4.4)
Appalachian Power Co [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		5		(5)		1.3
Change in Fair Value Recognized in AOCI		7		13.4		(3.3)
Commodity
Generation and Marketing Revenues		2,809.2		2,911.1		2,993.2
Interest Rate
Interest Expense		217.6		205		194.8
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		(6.1)		(4.3)		(4.1)
Income Tax (Expense) Benefit		4.3		(78)		(44.9)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		(4.8)		(3.4)		(3.3)
Net Current Period Other Comprehensive Income (Loss)		2.2		10		(6.6)
ASU 2018-02 Adoption						0.4
Ending Balance in AOCI		7.2		5		(5)
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		9.2		11.7		14.8
Change in Fair Value Recognized in AOCI		0		0		0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		(4.8)		(3.2)		(3.9)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		(3.8)		(2.5)		(3.1)
Net Current Period Other Comprehensive Income (Loss)		(3.8)		(2.5)		(3.1)
ASU 2018-02 Adoption						0
Ending Balance in AOCI		5.4		9.2		11.7
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		(5.1)		(18.5)		(15.7)
Change in Fair Value Recognized in AOCI		7.7		13.4		(2.6)
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)		7.7		13.4		(2.6)
ASU 2018-02 Adoption						(0.2)
Ending Balance in AOCI		2.6		(5.1)		(18.5)
Appalachian Power Co [Member] | Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)		2.2		10		(6.6)
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
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		0.9		1.8		2.2
Change in Fair Value Recognized in AOCI		(0.7)		0		0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		(1.3)		(1.1)		(1.1)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		(1)		(0.9)		(0.9)
Net Current Period Other Comprehensive Income (Loss)		(1.7)		(0.9)		(0.9)
ASU 2018-02 Adoption						0.5
Ending Balance in AOCI		(0.8)		0.9		1.8
Appalachian Power Co [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale		360.3		391		503.5
Indiana Michigan Power Co [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(11.6)		(13.8)		(12.1)
Change in Fair Value Recognized in AOCI		3.1		0.8		(0.6)
Commodity
Generation and Marketing Revenues		2,236		2,308.1		2,381
Interest Rate
Interest Expense		112.3		117.9		124.1
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		1.9		1.8		2
Income Tax (Expense) Benefit		(7.5)		(10.6)		29.1
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		1.5		1.4		1.6
Net Current Period Other Comprehensive Income (Loss)		4.6		2.2		1
ASU 2018-02 Adoption						(2.4)
Ending Balance in AOCI		(7)		(11.6)		(13.8)
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		4.9		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		(0.1)		(0.2)		0
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		(0.1)		(0.2)		0
Net Current Period Other Comprehensive Income (Loss)		(0.1)		(0.2)		0
ASU 2018-02 Adoption						0
Ending Balance in AOCI		4.8		4.9		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		(6.6)		(7.4)		(6.5)
Change in Fair Value Recognized in AOCI		3.1		0.8		(0.6)
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)		3.1		0.8		(0.6)
ASU 2018-02 Adoption						(0.3)
Ending Balance in AOCI		(3.5)		(6.6)		(7.4)
Indiana Michigan Power Co [Member] | Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)		4.6		2.2		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		(9.9)		(11.5)		(10.7)
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		1.6
Net Current Period Other Comprehensive Income (Loss)		1.6		1.6		1.6
ASU 2018-02 Adoption						(2.4)
Ending Balance in AOCI		(8.3)		(9.9)		(11.5)
Indiana Michigan Power Co [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale		182.2		232.3		221.8
Ohio Power Co [Member]
Commodity
Generation and Marketing Revenues		2,665		2,748.8		3,079.9
Interest Rate
Interest Expense		117.2		106.2		100.7
Pension and OPEB
Income Tax (Expense) Benefit		45.2		34.9		24
Net Current Period Other Comprehensive Income (Loss)				(1)		(1.3)
ASU 2018-02 Adoption						0.4
Ohio Power Co [Member] | Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)				(1)		(1.3)
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		0		1		1.9
Change in Fair Value Recognized in AOCI		0		0		0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit				(1.3)		(1.7)
Income Tax (Expense) Benefit		0
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit				(1)		(1.3)
Net Current Period Other Comprehensive Income (Loss)		0		(1)		(1.3)
ASU 2018-02 Adoption						0.4
Ending Balance in AOCI		0		0		1
Ohio Power Co [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale		549.2		607.3		684.6
Public Service Co Of Oklahoma [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		1.1
Commodity
Generation and Marketing Revenues		1,263.9		1,512.8		1,536.4
Interest Rate
Interest Expense		60.3		66.5		63.5
Pension and OPEB
Income Tax (Expense) Benefit		5.2		7.5		5
Net Current Period Other Comprehensive Income (Loss)		(1)		(1)		(1)
ASU 2018-02 Adoption						0.5
Ending Balance in AOCI		0.1		1.1
Public Service Co Of Oklahoma [Member] | Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)		(1)		(1)		(1)
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		1.1		2.1		2.6
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)		(1)
Net Current Period Other Comprehensive Income (Loss)		(1)		(1)		(1)
ASU 2018-02 Adoption						0.5
Ending Balance in AOCI		0.1		1.1		2.1
Public Service Co Of Oklahoma [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale		427.9		458.9		479.9
Southwestern Electric Power Co [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(1.3)		(5.4)		(4)
Change in Fair Value Recognized in AOCI		3.2		3.7		(0.8)
Commodity
Generation and Marketing Revenues		1,735.3		1,799.2		1,817
Interest Rate
Interest Expense		118.5		119.1		127.9
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		0		0.5		0.3
Income Tax (Expense) Benefit		9.4		(4.7)		20.4
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		0		0.4		0.3
Net Current Period Other Comprehensive Income (Loss)		3.2		4.1		(0.5)
ASU 2018-02 Adoption						(1.3)
Ending Balance in AOCI		1.9		(1.3)		(5.4)
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		(1.3)		(0.2)		1.2
Change in Fair Value Recognized in AOCI		0		0		0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		(1.9)		(1.4)		(1.8)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		(1.5)		(1.1)		(1.4)
Net Current Period Other Comprehensive Income (Loss)		(1.5)		(1.1)		(1.4)
ASU 2018-02 Adoption						0
Ending Balance in AOCI		(2.8)		(1.3)		(0.2)
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		1.8		(1.9)		0.8
Change in Fair Value Recognized in AOCI		3.2		3.7		(3.1)
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)		3.2		3.7		(3.1)
ASU 2018-02 Adoption						0.4
Ending Balance in AOCI		5		1.8		(1.9)
Southwestern Electric Power Co [Member] | Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)		3.2		4.1		(0.5)
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		(1.8)		(3.3)		(6)
Change in Fair Value Recognized in AOCI		0		0		2.3
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		1.9		1.9		2.1
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		1.5				1.7
Net Current Period Other Comprehensive Income (Loss)		1.5		1.5		4
ASU 2018-02 Adoption						(1.3)
Ending Balance in AOCI		(0.3)		(1.8)		(3.3)
Southwestern Electric Power Co [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale		161		179.5		177.1
Reclassifications from Accumulated Other Comprehensive Income [Member]
Interest Rate
Interest Expense	[2]	4.9		1.5		1.1
Pension and OPEB
Amortization of Prior Service Cost (Credit)		(19.2)		(19.2)		(19.5)
Amortization of Actuarial (Gains) Losses		10.3		12.1		12.8
Income Tax (Expense) Benefit		34.2		11.3		(8)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Securities Available for Sale [Member]
Interest Rate
Interest Expense	[2]					0
Pension and OPEB
Amortization of Prior Service Cost (Credit)						0
Amortization of Actuarial (Gains) Losses						0
Income Tax (Expense) Benefit						0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Interest Rate
Interest Expense	[2]	0		0		0
Pension and OPEB
Amortization of Prior Service Cost (Credit)		(19.2)		(19.2)		(19.5)
Amortization of Actuarial (Gains) Losses		10.3		12.1		12.8
Income Tax (Expense) Benefit		(1.9)		(1.5)		(1.4)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Interest Rate
Interest Expense	[2]	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	[2]	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		35.1		12.6		(6.9)
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	[2]	4.9		1.5		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		1		0.2		0.3
Reclassifications from Accumulated Other Comprehensive Income [Member] | Generation and Marketing Revenues [Member]
Commodity
Generation and Marketing Revenues	[2]	(0.4)		(0.2)		(0.1)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Generation and Marketing Revenues [Member] | Securities Available for Sale [Member]
Commodity
Generation and Marketing Revenues	[2]					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	[2]	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	[2]	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	[2]	(0.4)		(0.2)		(0.1)
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	[2]	0		0		0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale	[2]	167.6		59.5		(32.6)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Purchased Electricity for Resale [Member] | Securities Available for Sale [Member]
Commodity
Purchased Electricity for Resale	[2]					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	[2]	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	[2]	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	[2]	167.6		59.5		(32.6)
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	[2]	0		0		0
Reclassifications from Accumulated Other Comprehensive Income [Member] | AEP Texas Inc. [Member]
Interest Rate
Interest Expense	[2]	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		0.3		0.4
Income Tax (Expense) Benefit		0.3		0.3		0.4
Reclassifications from Accumulated Other Comprehensive Income [Member] | AEP Texas Inc. [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Interest Rate
Interest Expense	[2]	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		0.3		0.4
Income Tax (Expense) Benefit		0		0		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	[2]	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	[2]	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		0.3
Reclassifications from Accumulated Other Comprehensive Income [Member] | Appalachian Power Co [Member]
Interest Rate
Interest Expense	[2]	(1.3)		(1.1)		(1.1)
Pension and OPEB
Amortization of Prior Service Cost (Credit)		(5.3)		(5.3)		(5.2)
Amortization of Actuarial (Gains) Losses		0.5		2.1		1.3
Income Tax (Expense) Benefit		(1.3)		(0.9)		(0.8)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Appalachian Power Co [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Interest Rate
Interest Expense	[2]	0		0		0
Pension and OPEB
Amortization of Prior Service Cost (Credit)		(5.3)		(5.3)		(5.2)
Amortization of Actuarial (Gains) Losses		0.5		2.1		1.3
Income Tax (Expense) Benefit		(1)		(0.7)		(0.8)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Appalachian Power Co [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Interest Rate
Interest Expense	[2]	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	[2]	(1.3)		(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		(0.3)		(0.2)		(0.2)
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		2
Pension and OPEB
Amortization of Prior Service Cost (Credit)		(0.8)		(0.8)		(0.8)
Amortization of Actuarial (Gains) Losses		0.7		0.6		0.8
Income Tax (Expense) Benefit		0.4		0.4		0.4
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	[2]	0		0		0
Pension and OPEB
Amortization of Prior Service Cost (Credit)		(0.8)		(0.8)		(0.8)
Amortization of Actuarial (Gains) Losses		0.7		0.6		0.8
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	[2]	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		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		0.4
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	[2]	0		(1.3)		(1.7)
Pension and OPEB
Amortization of Actuarial (Gains) Losses		0
Income Tax (Expense) Benefit		0		(0.3)		(0.4)
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	[2]	(1.3)		(1.3)		(1.3)
Pension and OPEB
Income Tax (Expense) Benefit		(0.3)		(0.3)		(0.3)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Southwestern Electric Power Co [Member]
Interest Rate
Interest Expense	[2]	1.9		1.9		2.1
Pension and OPEB
Amortization of Prior Service Cost (Credit)		(2)		(2)		(2)
Amortization of Actuarial (Gains) Losses		0.1		0.6		0.2
Income Tax (Expense) Benefit		0		0.1		0
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	[2]	0		0		0
Pension and OPEB
Amortization of Prior Service Cost (Credit)		(2)		(2)		(2)
Amortization of Actuarial (Gains) Losses		0.1		0.6		0.2
Income Tax (Expense) Benefit		(0.4)		(0.3)		(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	[2]	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	[2]	1.9		1.9		2.1
Pension and OPEB
Amortization of Prior Service Cost (Credit)		0		0		0
Amortization of Actuarial (Gains) Losses		0		0		0
Income Tax (Expense) Benefit		$ 0.4		$ 0.4		$ 0.4
[1]	The change in fair value includes $6 million and $4 million related to AEP's investment in joint venture wind farms acquired as part of the purchase of Sempra Renewables LLC for the years ended December 31, 2020 and December 31, 2019. See “Sempra Renewables LLC” section of Note 17 for additional information.
[2]	Amounts reclassified to the referenced line item on the statements of income.

Rate Matters East Companies (De

Rate Matters East Companies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Public Utilities, General Disclosures [Line Items]
Other Asset Impairment Charges	$ 0	$ 156.4	$ 70.6
Total Property, Plant and Equipment, Net	63,901.6	60,138.1
Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Other Asset Impairment Charges	0	92.9	$ 0
Total Property, Plant and Equipment, Net	11,394.1	11,081.9
Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Total Property, Plant and Equipment, Net	7,052.3	6,899.7
Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Total Property, Plant and Equipment, Net	$ 7,452.1	6,907
2017-2019 Virginia Triennial Review [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 for Prior Period	9.42%
Requested Annual Increase	$ 65
Requested Return on Equity	9.90%
Amount Of Increased Depreciation Expense Requested	$ 19
Amount of Increase Related to Calculated Shortfall	$ 8
Total Basis Point Band for Authorized Return on Equity	140.00%
Approved Return on Common Equity	9.20%
Net Increase in Pretax Income Due to Virginia SCC Order	$ 40
Pretax Income Reduction Related to 2018 and 2019 Depreciation Studies	47
Reduction to revenues for amounts recognized in advance of the recording of depreciation expense for the periods January 2018 through October 2020	44
Increase in Depreciation Expense for the Periods November and December 2020	3
Corresponding Regulatory Liability that was Recorded for Reduction to Revenues	44
West Virginia ENEC and Vegetation Management Riders [Member]
Public Utilities, General Disclosures [Line Items]
Increase in Rider Rates related to Expanded Net Energy Cost and Vegetation Management	101
Refund for Excess ADIT Not Subject to Rate Normalization Requirements	38
West Virginia ENEC and Vegetation Management Riders [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Increase in Rider Rates related to Expanded Net Energy Cost and Vegetation Management	81
Refund for Excess ADIT Not Subject to Rate Normalization Requirements	31
2019 Indiana Base Rate Case [Member] | Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase	$ 172
Requested Return on Equity	10.50%
Approved Return on Common Equity	9.70%
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
Approved Annual Revenue Increase	60
Initial Phased in Annual Increase	44
Impact on Pretax Earnings due to Loss of Significant Contract	20
2020 Kentucky Base Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase	$ 65
Requested Return on Equity	10.00%
Approved Return on Common Equity	9.30%
Approved Annual Revenue Increase	$ 53
Requested Recovery Amount of Previously Authorized Deferral	50
Approved Annual Revenue Increase Prior to Rehearing	52
2020 Ohio Base Rate Case [Member] | Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase	$ 42
Requested Return on Equity	10.15%
Staff Recommended Annual Revenue Cap for the DIR in 2021	$ 57
Staff Recommended Annual Revenue Cap for the DIR in 2022	78
Staff Recommended Annual Revenue Cap for the DIR in 2023	96
Staff Recommended Annual Revenue Cap for the DIR for the First Five Months of 2024	46
2020 Ohio Base Rate Case [Member] | Ohio Power Co [Member] | Demand Side Management Programs [Member]
Public Utilities, General Disclosures [Line Items]
Staff Recommended Adjustments to Companies Request	40
2020 Ohio Base Rate Case [Member] | Ohio Power Co [Member] | Employee Related Expense [Member]
Public Utilities, General Disclosures [Line Items]
Staff Recommended Adjustments to Companies Request	23
2020 Ohio Base Rate Case [Member] | Ohio Power Co [Member] | Rate Base [Member]
Public Utilities, General Disclosures [Line Items]
Staff Recommended Adjustments to Companies Request	19
2020 Ohio Base Rate Case [Member] | Ohio Power Co [Member] | Property Tax [Member]
Public Utilities, General Disclosures [Line Items]
Staff Recommended Adjustments to Companies Request	17
2020 Ohio Base Rate Case [Member] | Ohio Power Co [Member] | Other Various Expenses [Member]
Public Utilities, General Disclosures [Line Items]
Staff Recommended Adjustments to Companies Request	15
2020 Ohio Base Rate Case [Member] | Ohio Power Co [Member] | Depreciation Expense [Member]
Public Utilities, General Disclosures [Line Items]
Staff Recommended Adjustments to Companies Request	11
2020 Ohio Base Rate Case [Member] | Ohio Power Co [Member] | Vegetation Management Programs [Member]
Public Utilities, General Disclosures [Line Items]
Staff Recommended Adjustments to Companies Request	10
2019 Ohio DIR Audit [Member]
Public Utilities, General Disclosures [Line Items]
DIR Revenue Amount above 2019 Authorized Limit	$ 17
Minimum [Member] | 2017-2019 Virginia Triennial Review [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Approved Return on Common Equity	8.50%
Minimum [Member] | 2020 Ohio Base Rate Case [Member] | Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Staff Recommended Annual Rate Decrease	$ 102
Staff Recommended Return on Common Equity	8.76%
Minimum [Member] | 2020 Ohio Base Rate Case [Member] | Ohio Power Co [Member] | Return on Common Equity [Member]
Public Utilities, General Disclosures [Line Items]
Staff Recommended Adjustments to Companies Request	$ 9
Maximum [Member] | 2017-2019 Virginia Triennial Review [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Approved Return on Common Equity	9.90%
Maximum [Member] | 2019 Indiana Base Rate Case [Member] | Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Approved Annual Revenue Increase	$ 77
Maximum [Member] | 2020 Ohio Base Rate Case [Member] | Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Staff Recommended Annual Rate Decrease	$ 123
Staff Recommended Return on Common Equity	9.78%
Maximum [Member] | 2020 Ohio Base Rate Case [Member] | Ohio Power Co [Member] | Return on Common Equity [Member]
Public Utilities, General Disclosures [Line Items]
Staff Recommended Adjustments to Companies Request	$ 30
Plant in Service [Member] | Maximum [Member] | 2020 Ohio Base Rate Case [Member] | Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Recommended Disallowance from Staff or Intervenors	27
Plant Retirement Costs - Unrecovered Plant [Member] | 2017-2019 Virginia Triennial Review [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Net Book Value of Retired Plants	93
Other Asset Impairment Charges	93
Virginia Jurisdictional AMR Meters [Member] | 2017-2019 Virginia Triennial Review [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Total Property, Plant and Equipment, Net	35	51
Virginia Jurisdictional AMI Meters [Member] | 2017-2019 Virginia Triennial Review [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Total Property, Plant and Equipment, Net	$ 73	$ 75

Rate Matters West Companies (De

Rate Matters West Companies (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)customer	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Public Utilities, General Disclosures [Line Items]
Other Asset Impairment Charges	$ 0	$ 156.4	$ 70.6
Total Property, Plant and Equipment, Net	63,901.6	60,138.1
AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Other Asset Impairment Charges	0	32.5	0
Total Property, Plant and Equipment, Net	9,813.6	8,845.1
Public Service Co Of Oklahoma [Member]
Public Utilities, General Disclosures [Line Items]
Total Property, Plant and Equipment, Net	4,320	4,103.3
Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Provision for Refund	(2)	(32)	$ (6.7)
Total Property, Plant and Equipment, Net	7,088.2	$ 7,095.2
2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase	$ 56
Requested Return on Equity	10.50%
Refund for Excess ADIT	$ 21
Approved Annual Revenue Decrease	$ 40
Approved Return on Common Equity	9.40%
Public Utilities, Approved Debt Capital Structure, Percentage	57.50%
Public Utilities, Approved Equity Capital Structure, Percentage	42.50%
Refund for Excess ADIT Associated with Certain Depreciable Property	$ 275
Other Asset Impairment Charges	33
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]
Item to be Refunded in Commission Order	77
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]
Item to be Refunded in Commission Order	31
2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member] | Previously Collected Rates Subject to Reconciliation [Member]
Public Utilities, General Disclosures [Line Items]
Item to be Refunded in Commission Order	30
Provision for Refund	30
2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member] | Vegetation Management
Public Utilities, General Disclosures [Line Items]
Approved Item in Commission Order	26
2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member] | Capital Investments [Member]
Public Utilities, General Disclosures [Line Items]
Disallowed Item in Commission Order	23
2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member] | Rate Case Expense [Member]
Public Utilities, General Disclosures [Line Items]
Disallowed Item in Commission Order	4
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]
Other Asset Impairment Charges	10
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	79
ETT Interim Transmission Rates [Member]
Public Utilities, General Disclosures [Line Items]
Approved Annual Revenue Decrease	$ 8
Parent Ownership Interest In ETT	50.00%
AEP Share Of ETT Cumulative Revenues Subject To Review	$ 1,200
Approved interim transmission cost of service line item decrease	2
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] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net	$ 1,400
Texas Jurisdictional Share of Turk Plant	33.00%
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] | 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
Refund for Over Collections	$ 6
Hurricane Laura [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Customers without Power | customer	130,000
Incremental Other Operation and Maintenance Expenses	$ 84
Capitalized Storm Costs	23
Hurricane Laura [Member] | Southwestern Electric Power Co [Member] | Louisiana Jurisdiction [Member]
Public Utilities, General Disclosures [Line Items]
Incremental Other Operation and Maintenance Expenses	$ 82
Hurricane Delta [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Customers without Power | customer	23,000
Incremental Other Operation and Maintenance Expenses	$ 17
Capitalized Storm Costs	2
2020 Texas Base Rate Case [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase	$ 105
Requested Return on Equity	10.35%
Requested Net Annual Increase	$ 90
Amount of Increase Related to Vegetation Management	5
Amount of Increase Related to Annual Depreciation Expense	10
Amount of Increase Related to Storm Catastrophe Reserve	2
Requested Recovery of Dolet Hills Power Station	45
2020 Louisiana Base Rate Case [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Requested Annual Increase	$ 134
Requested Return on Equity	10.35%
Amount of Increase Related to Annual Depreciation Expense	$ 32
Amount of Increase Related to Recovering Deferred Hurricane Costs	10
OKTCo Radial Asset Transfer [Member] | Public Service Co Of Oklahoma [Member] | Net Book Value of Radial Assets [Member]
Public Utilities, General Disclosures [Line Items]
Total Property, Plant and Equipment, Net	$ 60

Effects of Regulation (Details)

Effects of Regulation (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2014
Regulated Generating Unit to be Retired
Net Investment		$ 63,901.6	$ 60,138.1
Materials and Supplies		680.6	640.7
Annual Depreciation		2,487.5	2,203.7	$ 1,965
Regulatory Assets
Current Regulatory Assets		90.7	92.9
Noncurrent Regulatory Assets		3,527	3,158.8
Regulatory Liabilities
Current Regulatory Liabilities		52.6	86.6
Noncurrent Regulatory Liabilities		8,378.7	8,457.6
Effects of Regulation Textuals [Abstract]
Revisions in Cash Flow Estimates	[1],[2],[3],[4],[5]	183.1	67
Secured Debt		716.4	1,025.1
Accumulated Depreciation and Amortization		20,411.4	19,007.6
Asset Impairments and Other Related Charges		$ 0	$ 156.4	$ 70.6
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	21.00%	21.00%	35.00%	35.00%
AEP Texas Inc. [Member]
Regulated Generating Unit to be Retired
Net Investment		$ 9,813.6	$ 8,845.1
Materials and Supplies		70	56.7
Annual Depreciation		364.2	365.9	$ 262.2
Regulatory Assets
Noncurrent Regulatory Assets		266.8	280.6
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1,270.8	1,316.9
Effects of Regulation Textuals [Abstract]
Revisions in Cash Flow Estimates	[2],[3],[5]	(16.8)	0.1
Secured Debt		492.6	776.8
Accumulated Depreciation and Amortization		1,529.3	1,758.1
Asset Impairments and Other Related Charges		$ 0	$ 32.5	$ 0
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	21.00%	21.00%	35.00%
AEP Transmission Co [Member]
Regulated Generating Unit to be Retired
Net Investment		$ 10,772.8	$ 9,490.9
Materials and Supplies		8.5	13.8
Annual Depreciation		249	176	$ 133.9
Regulatory Assets
Noncurrent Regulatory Assets		15.1	4.2
Regulatory Liabilities
Noncurrent Regulatory Liabilities		581.8	540.9
Effects of Regulation Textuals [Abstract]
Accumulated Depreciation and Amortization		$ 572.8	$ 402.3
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	21.00%	21.00%	35.00%
Appalachian Power Co [Member]
Regulated Generating Unit to be Retired
Net Investment		$ 11,394.1	$ 11,081.9
Materials and Supplies		99.6	105.2
Annual Depreciation		507.8	466.5	$ 428.1
Regulatory Assets
Current Regulatory Assets		5.3	42.5
Noncurrent Regulatory Assets		686.3	457.2
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1,224.7	1,268.7
Effects of Regulation Textuals [Abstract]
Revisions in Cash Flow Estimates	[2],[3],[5]	200.9	6.7
Secured Debt		223.8	248.3
Accumulated Depreciation and Amortization		4,716.2	4,432.3
Asset Impairments and Other Related Charges		$ 0	$ 92.9	$ 0
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	21.00%	21.00%	35.00%
Indiana Michigan Power Co [Member]
Regulated Generating Unit to be Retired
Net Investment		$ 7,052.3	$ 6,899.7
Materials and Supplies		175.8	171.3
Annual Depreciation		393.3	330.6	$ 278.9
Regulatory Assets
Current Regulatory Assets		5.4	3
Noncurrent Regulatory Assets		404.8	482.1
Regulatory Liabilities
Current Regulatory Liabilities		20.8	6.1
Noncurrent Regulatory Liabilities		2,041.9	1,891.4
Effects of Regulation Textuals [Abstract]
Revisions in Cash Flow Estimates	[2],[3],[4],[5]	(4.9)	0.1
Accumulated Depreciation and Amortization		$ 3,552.5	$ 3,294.3
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	21.00%	21.00%	35.00%
Ohio Power Co [Member]
Regulated Generating Unit to be Retired
Net Investment		$ 7,452.1	$ 6,907
Materials and Supplies		66.9	52.3
Annual Depreciation		275	229.4	$ 232.6
Regulatory Assets
Noncurrent Regulatory Assets		385.8	351.8
Regulatory Liabilities
Current Regulatory Liabilities		3.9	2.8
Noncurrent Regulatory Liabilities		1,005.2	1,090.9
Effects of Regulation Textuals [Abstract]
Revisions in Cash Flow Estimates	[2],[5]	0	0.2
Accumulated Depreciation and Amortization		$ 2,350	$ 2,263
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	21.00%	21.00%	35.00%
Public Service Co Of Oklahoma [Member]
Regulated Generating Unit to be Retired
Net Investment		$ 4,320	$ 4,103.3
Materials and Supplies		54	46.8
Annual Depreciation		171.9	162.5	$ 155.5
Regulatory Assets
Current Regulatory Assets		30.1	0
Noncurrent Regulatory Assets		375	375.2
Regulatory Liabilities
Current Regulatory Liabilities		0	63.9
Noncurrent Regulatory Liabilities		802.2	837.2
Effects of Regulation Textuals [Abstract]
Revisions in Cash Flow Estimates	[2],[3],[5]	(4.8)	2.6
Accumulated Depreciation and Amortization		$ 1,605.6	$ 1,580.1
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	21.00%	21.00%	35.00%
Southwestern Electric Power Co [Member]
Regulated Generating Unit to be Retired
Net Investment		$ 7,088.2	$ 7,095.2
Materials and Supplies		95.8	94
Annual Depreciation		271.2	247.9	$ 237
Regulatory Assets
Current Regulatory Assets		2.6	4.9
Noncurrent Regulatory Assets		403.1	222.4
Regulatory Liabilities
Current Regulatory Liabilities		37.6	13.6
Noncurrent Regulatory Liabilities		863.4	892.3
Effects of Regulation Textuals [Abstract]
Revisions in Cash Flow Estimates	[1],[2],[3],[5]	10.1	6.9
Accumulated Depreciation and Amortization		$ 3,158.5	$ 2,873.7
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	21.00%	21.00%	35.00%
Amount of Fuel Costs Under Review		$ 1,700
Net Over-Recovered Fuel Costs		35
Southwestern Electric Power Co [Member] | TEXAS
Effects of Regulation Textuals [Abstract]
Amount of Fuel Costs Under Review		616
Recommended Disallowance from Staff or Intervenors		125
Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		7,889.8	$ 7,594.6
Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1,276.5	954.9
Regulatory Liabilities Approved for Payment [Member] | AEP Transmission Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		581.8	540.9
Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1,224.7	1,268.7
Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		2,041.9	1,891.4
Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1,005	1,090.7
Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		802.2	837.2
Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		550	572.6
Regulatory Liabilities Pending Final Regulatory Determination [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		488.9	863
Regulatory Liabilities Pending Final Regulatory Determination [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		(5.7)	362
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	[6]	313.4	319.7
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		3,091.2	2,934.5
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		723.6	699.7
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Transmission Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		198.6	141
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		679.2	635.8
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		185.6	167
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		458.4	484.8
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		289.9	286.8
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		473.3	456.2
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		2.5	0
Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		2.5	0
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		2,005.9	1,808.4
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		57.9	64.9
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		72.8	65.6
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1,601.5	1,370
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		50.8	81.7
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		52.3	56.2
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		8.2	10.8
Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1.5	0.2
Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities	[7]	2,792.7	2,851.7
Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities	[8]	495	190.3
Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Transmission Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities	[9]	383.2	399.9
Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities	[10]	472.7	567.3
Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities	[11]	254.8	354.4
Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities	[12]	495.8	524.2
Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities	[13]	460	494.2
Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities	[6]	68.5	105.6
Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities	[7]	484.9	862.8
Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities	[14]	(8.2)	362
Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		442.2	181.7
Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		32.9	30.8
Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		43.8	30.6
Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		4.3	7.7
Regulatory Assets Pending Final Regulatory Approval [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		8.4	0.1
Regulatory Assets Pending Final Regulatory Approval [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		50.5	34.6
Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		247.3	46.3
Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		3,084.8	2,977.1
Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		233.9	249.8
Regulatory Assets Approved for Recovery [Member] | AEP Transmission Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		15.1	4.2
Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		642.5	426.6
Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		400.5	474.4
Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		377.4	351.7
Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		324.5	340.6
Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		155.8	176.1
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		220.7	93.5
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		16.3	0
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		3.7	0.5
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		0.5	0
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		34.4	27.4
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		124.4	35.4
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		1,131.4	1,089.2
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		29.3	61.7
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		123.4	86.9
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		298.4	296.4
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		60.2	31.4
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		253.7	255.3
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		33.6	37.2
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		221.5	88.2
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		16.6	30.8
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		40.1	30.1
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		3.8	7.7
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		16.1	7.2
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		122.9	10.9
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		1,953.4	1,887.9
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		204.6	188.1
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		519.1	339.7
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		102.1	178
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		317.2	320.3
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		70.8	85.3
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		122.2	138.9
Northeastern Plant, Unit 3 [Member] | Generating Units Probable of Abandonment [Member] | Public Service Co Of Oklahoma [Member]
Regulated Generating Unit to be Retired
Net Investment		198.4
Accelerated Depreciation Regulatory Asset		110.4
Cost of Removal Regulatory Liability	[15]	$ 19.8
Expected Retirement Date		2026
Annual Depreciation	[16]	$ 14.9
Dolet Hills Power Station [Member] | Generating Units Probable of Abandonment [Member] | Southwestern Electric Power Co [Member]
Regulated Generating Unit to be Retired
Net Investment		74.4
Accelerated Depreciation Regulatory Asset		71.2
Cost of Removal Regulatory Liability		$ 24
Expected Retirement Date		2021
Annual Depreciation	[16]	$ 60.8
Pirkey Power Plant [Member] | Generating Units Probable of Abandonment [Member] | Southwestern Electric Power Co [Member]
Regulated Generating Unit to be Retired
Net Investment		199.5
Accelerated Depreciation Regulatory Asset		12.2
Cost of Removal Regulatory Liability		$ 38.7
Expected Retirement Date		2023
Annual Depreciation	[16]	$ 13.8
Welsh Plant, Units 1 and 3 [Member] | Generating Units Probable of Abandonment [Member] | Southwestern Electric Power Co [Member]
Regulated Generating Unit to be Retired
Net Investment		549.8
Accelerated Depreciation Regulatory Asset		3.6
Cost of Removal Regulatory Liability	[17]	$ 57.6
Expected Retirement Date		2028
Annual Depreciation	[16]	$ 33.3
Deferred Fuel Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member]
Regulatory Liabilities
Current Regulatory Liabilities		$ 27.6	77.5
Remaining Refund Period		1 year
Deferred Fuel Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Liabilities
Current Regulatory Liabilities		$ 0	63.9
Remaining Refund Period
Deferred Fuel Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Current Regulatory Liabilities	[18]	$ 37.6	13.6
Remaining Refund Period	[18]	1 year
Deferred Fuel Costs [Member] | Regulatory Liabilities Currently Not Paying Return [Member]
Regulatory Liabilities
Current Regulatory Liabilities		$ 25	9.1
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		$ 20.8	6.1
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		$ 3.9	2.8
Remaining Refund Period		1 year
Deferred Fuel Costs [Member] | Regulatory Assets Currently Earning Return [Member]
Regulatory Assets
Current Regulatory Assets		$ 41.4	44.7
Remaining Recovery Period		1 year
Deferred Fuel Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Appalachian Power Co [Member]
Regulatory Assets
Current Regulatory Assets		$ 3.3	36.8
Remaining Recovery Period		1 year
Deferred Fuel Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Current Regulatory Assets		$ 5.4	3
Remaining Recovery Period		1 year
Deferred Fuel Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Current Regulatory Assets		$ 30.1	0
Remaining Recovery Period		1 year
Deferred Fuel Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Current Regulatory Assets	[19]	$ 2.6	4.9
Remaining Recovery Period		1 year
Deferred Fuel Costs [Member] | Regulatory Assets Currently Not Earning Return [Member]
Regulatory Assets
Current Regulatory Assets		$ 49.3	48.2
Remaining Recovery Period		1 year
Deferred Fuel Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Appalachian Power Co [Member]
Regulatory Assets
Current Regulatory Assets		$ 2	5.7
Remaining Recovery Period		1 year
Dolet Hills Power Station Accelerated Depreciation [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 71.2	0
Dolet Hills Power Station Accelerated Depreciation [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		71.2	0
Kentucky Deferred Purchase Power Expenses [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		41.3	30.2
Plant Retirement Costs - Unrecovered Plant, Louisiana [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		35.2	35.2
Plant Retirement Costs - Unrecovered Plant, Louisiana [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	35.2
Pirkey Power Plant Accelerated Depreciation [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		12.2	0
Welsh Plant, Units 1 and 3 Accelerated Depreciation [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		3.6	0
Oklaunion Power Station Accelerated Depreciation [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		34.4	27.4
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		34.4	27.4
COVID-19 - Virginia [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		3.7	0
Plant Retirement Costs - Materials and Supplies [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		0	0.5
Other Regulatory Assets Pending Final Regulatory Approval [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		38.6	0.7
Other Regulatory Assets Pending Final Regulatory Approval [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		0.5	0
Other Regulatory Assets Pending Final Regulatory Approval [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		2.2	0.2
Other Regulatory Assets Pending Final Regulatory Approval [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		32.7	21.5
Other Regulatory Assets Pending Final Regulatory Approval [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		2.3	1.4
Other Regulatory Assets Pending Final Regulatory Approval [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		3.4	0
Other Regulatory Assets Pending Final Regulatory Approval [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	0.1
Other Regulatory Assets Pending Final Regulatory Approval [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	0.1
Other Regulatory Assets Pending Final Regulatory Approval [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		14.5	3.7
Storm Related Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 11.5	21.3
Remaining Recovery Period		2 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		$ 11.5	21.3
Remaining Recovery Period		2 years
Storm Related Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 134.2	7.2
Storm Related Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		4	0
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		15.8	7.2
Storm Related Costs [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		99.3	0
Storm Related Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 17.1	0
Remaining Recovery Period		4 years
Plant Retirement Costs - Asset Retirement Obligation Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 107.1	87.4
Remaining Recovery Period		20 years
Plant Retirement Costs - Asset Retirement Obligation Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 25.9	30.1
Plant Retirement Costs - Asset Retirement Obligation Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		25.9	30.1
Plant Retirement Costs - Asset Retirement Obligation Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 212.7	28.8
Remaining Recovery Period		22 years
Plant Retirement Costs - Asset Retirement Obligation Costs [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 202.7	0
Remaining Recovery Period		15 years
Environmental Expense Deferral - Virginia [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 9.3	0
COVID-19 - West Virginia [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		1.5	0
COVID-19 [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		24.9	0
COVID-19 [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		10.5	0
COVID-19 [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		3.8	0
COVID-19 [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		4.4	0
COVID-19 [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		0.3	0
Vegetation Management - AEP Texas [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member]
Regulatory Assets
Noncurrent Regulatory Assets		3.8	29.4
Vegetation Management Program [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		3.8	29.4
Vegetation Management Program [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 22.4	0
Remaining Recovery Period		5 years
Plant Retirement Costs - Unrecovered Plant [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets	[20]	$ 713.1	690.5
Remaining Recovery Period	[20]	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	[21]	$ 122.4	86.4
Remaining Recovery Period	[21]	23 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		$ 191.5	214.9
Remaining Recovery Period		8 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	[22]	$ 180.8	167
Remaining Recovery Period	[22]	20 years
Plant Retirement Costs - Unrecovered Plant, Arkansas [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 14.4	15.1
Remaining Recovery Period		22 years
Plant Retirement Costs - Unrecovered Plant, Texas [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 16.1	16.6
Remaining Recovery Period		21 years
Meter Replacement Costs [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 55.5	65.4
Remaining Recovery Period		7 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		$ 29.3	35.2
Remaining Recovery Period		6 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		$ 26.2	30.2
Remaining Recovery Period		7 years
Ohio Distribution Decoupling [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 46.6	31.4
Remaining Recovery Period		2 years
Ohio Distribution Decoupling [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 46.6	31.4
Remaining Recovery Period		2 years
Ohio Basic Transmission Cost Rider [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 12.3	0
Remaining Recovery Period		2 years
Environmental Controls Projects [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 38.6	41
Remaining Recovery Period		20 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		$ 26.5	27.8
Remaining Recovery Period		20 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		$ 12.1	13.2
Remaining Recovery Period		12 years
Rockport Plant Dry Sorbent Injection System and Selective Catalytic Reduction [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 34.4	13.5
Remaining Recovery Period		8 years
Rockport Plant Dry Sorbent Injection System and Selective Catalytic Reduction [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 34.4	13.5
Remaining Recovery Period		8 years
Cook Plant Uprate Project [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 30.2	32.6
Remaining Recovery Period		13 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		$ 30.2	32.6
Remaining Recovery Period		13 years
Advanced Metering System [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 16.3	0
Advanced Metering System [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		0	26.5
Advanced Metering System [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		0	26.5
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		94.4	79.6
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		1	0.5
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		7	6.9
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		1.3	0
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Public Service Co Of Oklahoma [Member]
Regulatory Assets
Noncurrent Regulatory Assets		0.5	0.6
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		7.1	8.9
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		181.4	132.8
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		12.4	12.6
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		12.7	14.4
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		16.3	22.3
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		15.8	15.7
Other Regulatory Assets Approved for Recovery [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		12.4	5.4
Other Regulatory Assets Approved for Recovery [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		17	19.7
Vegetation Management [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 67.8	43.6
Remaining Recovery Period		5 years
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		$ 0	7.6
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		9.1	7.2
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		$ 14.1	15.1
Remaining Recovery Period		14 years
Cook Plant Study Costs - Indiana [Member] | Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 10.1	0
Remaining Recovery Period		15 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		$ 11.1	13.4
Remaining Recovery Period		18 years
Pension and OPEB Funded Status [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 1,088.6	1,309.8
Remaining Recovery Period		12 years
Pension and OPEB Funded Status [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 145	172
Remaining Recovery Period		12 years
Pension and OPEB Funded Status [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 114.4	160.8
Remaining Recovery Period		12 years
Pension and OPEB Funded Status [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Indiana Michigan Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 25.7	67.5
Remaining Recovery Period		12 years
Pension and OPEB Funded Status [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 130.7	167.3
Remaining Recovery Period		12 years
Pension and OPEB Funded Status [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		$ 52.3	73.4
Remaining Recovery Period		12 years
Pension and OPEB Funded Status [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Southwestern Electric Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 89.1	102.6
Remaining Recovery Period		12 years
Unamortized Loss on Reacquired Debt [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 120	129
Remaining Recovery Period		28 years
Unamortized 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		$ 82.1	85.5
Remaining Recovery Period		25 years
Unamortized 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		$ 15.7	17.2
Remaining Recovery Period		28 years
Unamortized 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		$ 6.1	6.5
Remaining Recovery Period		18 years
Peak Demand Reduction/Energy Efficiency [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | AEP Texas Inc. [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 7.7	3.5
Remaining Recovery Period		2 years
Peak Demand Reduction/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		$ 16.8	19.5
Remaining Recovery Period		6 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		$ 111.3	106.8
Remaining Recovery Period		12 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		$ 110	103.6
Remaining Recovery Period		12 years
Virginia Transmission 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		$ 18.8	0
Remaining Recovery Period		2 years
Vegetation Management Program - West Virginia [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 45.4	43.6
Remaining Recovery Period		2 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		$ 39.5	63.8
Remaining Recovery Period		2 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		$ 39.5	63.8
Remaining Recovery Period		2 years
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		$ 33	7.3
Remaining Recovery 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		$ 15.1	4.2
Remaining Recovery Period		2 years
Postemployment Benefits [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 29.1	34.2
Remaining Recovery Period		3 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		$ 13.5	15.9
Remaining Recovery Period		3 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		$ 4.9	7.2
Remaining Recovery Period		3 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		$ 6.7	7.6
Remaining Recovery Period		3 years
PJM Annual Formula Rate True-up [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Appalachian Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 12.7	0
Remaining Recovery Period		2 years
OVEC Purchased Power [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 27.4	1.5
Remaining Recovery Period		2 years
OVEC Purchased Power [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member] | Ohio Power Co [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 27.4	1.5
Remaining Recovery Period		2 years
Fuel and Purchased Power Adjustment Rider [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 24	7.1
Remaining Recovery Period		2 years
Medicare Subsidy [Member] | Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Approved for Recovery [Member]
Regulatory Assets
Noncurrent Regulatory Assets		$ 18.6	23.2
Remaining Recovery Period		4 years
PJM Costs and Off-system Sales Margin Sharing - Indiana [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 13.3	17
Remaining Refund Period		2 years
Other Regulatory Liabilities Pending Final Regulatory Determination [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 2.5	0
Other Regulatory Liabilities Pending Final Regulatory Determination [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		2.5	0
Other Regulatory Liabilities Pending Final Regulatory Determination [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1.5	0.2
Other Regulatory Liabilities Pending Final Regulatory Determination [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	[7],[23]	3,485.7	3,303
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	[8],[24]	506	236.5
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	[9],[25]	531.5	535.7
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	[10],[26]	690	718.9
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	[11],[27]	450.6	470.9
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	[12],[28]	334.6	341.6
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	[13],[29]	397	405.8
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	[6],[30]	332.5	339.4
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	[7]	291.6	571.8
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	[14]	0	274.9
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	[6]	291.6	297
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	[7]	$ 714.9	890.5
Remaining Refund Period		10 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
Noncurrent Regulatory Liabilities	[8]	$ 41.7	0
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	[9]	$ (30.6)	(35.4)
Remaining Refund Period		8 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	[10]	$ 139.1	210.7
Remaining Refund Period		8 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	[11]	$ 136.2	184.5
Remaining Refund Period		4 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	[12]	$ 223.9	252.3
Remaining Refund Period		8 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	[13]	$ 71.3	96.3
Remaining Refund Period		4 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	[6],[31]	$ 11.5	27.8
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	[7],[32]	193.3	291
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	[14]	(8.2)	87.1
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	[6]	21.8	22.7
Excess ADIT that is Not Subject to Rate Normalization Requirements [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Pending Final Regulatory Determination [Member] | AEPTHCo's investment in ETT and Transource Energy [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		173	172
Asset Removal Costs [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities	[33]	3,061.9	2,876.7
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	[34]	718.3	689.6
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	[35]	198.6	141
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	[36]	678.9	635.3
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	[37]	168.2	166.7
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	[38]	458.4	446.3
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	[39]	289.9	286.8
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	[40]	470.9	453.4
Ohio Basic Transmission Cost Rider [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		0	37.2
Ohio 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		0	37.2
Deferred Investment Tax Credits [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 4.1	6.2
Remaining Refund Period		33 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		$ 0.3	0.5
Remaining Refund Period		33 years
Deferred Investment Tax Credits [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 216.7	215.3
Remaining Refund Period		34 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		$ 8.5	9.6
Remaining Refund Period		20 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		$ 21.3	25.8
Remaining Refund Period		19 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	51.5
Remaining Refund Period		24 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		$ 1.8	3.1
Remaining Refund Period		10 years
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 25.2	14.4
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		5.3	10.1
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		17.4	0.3
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		0	1.3
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Paying a Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		2.4	2.8
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		71	87.7
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1.2	4.8
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		12.3	18
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		30.1	24.9
Other Regulatory Liabilities Approved for Payment [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	2.9
Other Regulatory Liabilities Approved for Payment [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		1.3	4.7
Other Regulatory Liabilities Approved for Payment [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		1.2	1.7
Excess Nuclear Decommissioning Funding [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities	[41]	1,476.6	1,236
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	[42]	1,476.6	1,236
PJM Transmission Enhancement Refund [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 56.2	67.3
Remaining Refund Period		5 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		$ 16.3	19.5
Remaining Refund Period		5 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		$ 9.9	11.8
Remaining Refund Period		5 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		$ 24.5	29.4
Remaining Refund Period		5 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		$ 48.2	50.5
Remaining Refund Period		9 years
Transition and Restoration Charges [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | AEP Texas Inc. [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 48.2	50.5
Remaining Refund Period		9 years
2017-2019 Virginia Triennial Revenue Provision [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 44.2	0
Remaining Refund Period		28 years
2017-2019 Virginia Triennial Revenue Provision [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Appalachian Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 44.2	0
Remaining Refund Period		28 years
Spent Nuclear Fuel [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities	[41]	$ 43.1	43.6
Spent Nuclear Fuel [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities	[42]	43.1	43.6
Peak Demand Reduction/Energy Efficiency [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 26.3	23
Remaining Refund Period		2 years
Peak Demand Reduction/Energy Efficiency [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Ohio Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 19.9	19.7
Remaining Refund Period		2 years
Peak Demand Reduction/Energy Efficiency [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member] | Southwestern Electric Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 5.2	6
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		$ 17.9	27.2
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] | Indiana Michigan Power Co [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 7.2	10.9
Remaining Refund Period		2 years
Ohio Enhanced Service Reliability Plan [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 5.7	29.7
Remaining Refund Period		2 years
Ohio 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		$ 5.7	29.7
Remaining Refund Period		2 years
Virginia Transmission Rate Adjustment Clause [Member] | Regulatory Liabilities Currently Not Paying Return [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities		$ 0	28.1
Virginia 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		0	28.1
Income Taxes Subject to Flow Through [Member] | Income Tax Related Regulatory Liabilities [Member] | Regulatory Liabilities Approved for Payment [Member]
Regulatory Liabilities
Noncurrent Regulatory Liabilities	[7]	$ (1,407.9)	(1,341.8)
Remaining Refund Period		54 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	[8]	$ (52.7)	(46.2)
Remaining Refund Period		28 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	[9]	$ (117.7)	(100.4)
Remaining Refund Period		38 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	[10]	$ (356.4)	(362.3)
Remaining Refund Period		24 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	[11]	$ (332)	(301)
Remaining Refund Period		20 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	[12]	$ (62.7)	(69.7)
Remaining Refund Period		29 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	[13]	$ (8.3)	(7.9)
Remaining Refund Period		27 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	[6]	$ (275.5)	(261.6)
Remaining Refund Period		28 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		$ 19.2	13.7
Remaining Recovery Period		2 years
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		$ 7.4	10.9
Remaining Recovery 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		$ 8.2	$ 8.4
Remaining Recovery Period		36 years
Dolet Hills Generating Station and Related Fuel Operations | Southwestern Electric Power Co [Member]
Effects of Regulation Textuals [Abstract]
Percent of Fuel Supply Provided by DHLC		100.00%
Revisions in Cash Flow Estimates		$ 21
Share of Net Investment in Dolet Hills Power Station		151
Dolet Hills Lignite Company Unbilled Fixed Costs		131
Requested Fuel Cost Deferral		36
Pirkey Power Plant and Related Fuel Operations | Southwestern Electric Power Co [Member]
Effects of Regulation Textuals [Abstract]
Share of Net Investment in Pirkey Power Plant		212
Pirkey Power Plant and Sabine Unbilled Fixed Costs		193
2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member]
Effects of Regulation Textuals [Abstract]
Asset Impairments and Other Related Charges		$ 33
[1]	Includes ARO related to Sabine and DHLC.
[2]	Includes ARO related to asbestos removal.
[3]	Includes ARO related to ash disposal facilities.
[4]	Includes ARO related to nuclear decommissioning costs for the Cook Plant of $1.80 billion and $1.73 billion as of December 31, 2020 and 2019, respectively.
[5]	Unless discussed above, primarily related to ash ponds, landfills and mine reclamation, generally due to changes in estimated closure area, volumes and/or unit costs.
[6]	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.
[7]	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.
[8]	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.
[9]	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.
[10]	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.
[11]	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.
[12]	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.
[13]	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.
[14]	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.
[15]	Includes Northeastern Plant, Unit 4, which was retired in 2016. Removal of Northeastern Plant, Unit 4, will be performed with Northeastern Plant, Unit 3, after retirement.
[16]	Represents the amount of annual depreciation that has been collected from customers over the prior 12-month period.
[17]	Includes Welsh Plant, Unit 2, which was retired in 2016. Removal of Welsh Plant, Unit 2, will be performed with Welsh Plant, Units 1 and 3, after retirement.
[18]	(a) December 31, 2020 amount includes Arkansas and Texas jurisdictions. December 31, 2019 amount includes Texas and Louisiana jurisdictions.
[19]	December 31, 2020 amount includes Louisiana jurisdiction. December 31, 2019 amount includes Arkansas jurisdiction.
[20]	Northeastern Plant, Unit 3 is approved for recovery through 2040, but expected to retire in 2026. PSO records a regulatory asset for accelerated depreciation. See “Regulated Generating Units to be Retired” section above for additional information.
[21]	December 31, 2020 amount includes Virginia and West Virginia jurisdictions. December 31, 2019 amount includes West Virginia jurisdiction.
[22]	Northeastern Plant, Unit 3 is approved for recovery through 2040, but expected to retire in 2026. PSO records a regulatory asset for accelerated depreciation. See “Regulated Generating Units to be Retired” section above for additional information.
[23]	Refunded using ARAM.
[24]	Refunded using ARAM.
[25]	Refunded using ARAM.
[26]	Refunded using ARAM.
[27]	Refunded using ARAM.
[28]	Refunded using ARAM.
[29]	Refunded using ARAM.
[30]	Refunded using ARAM. (e) Current balance represents revisions to balances for jurisdictions having previously issued orders on treatment for refund, refund period to be addressed in future proceedings.
[31]	Current balance represents revisions to balances for jurisdictions having previously issued orders on treatment for refund, refund period to be addressed in future proceedings.
[32]	2020 and 2019 amounts include approximately $173 million and $172 million, respectively, 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.
[33]	Relieved as removal costs are incurred.
[34]	Relieved as removal costs are incurred.
[35]	Relieved as removal costs are incurred.
[36]	Relieved as removal costs are incurred.
[37]	Relieved as removal costs are incurred.
[38]	Relieved as removal costs are incurred.
[39]	Relieved as removal costs are incurred.
[40]	Relieved as removal costs are incurred.
[41]	Relieved when plant is decommissioned.
[42]	Relieved when plant is decommissioned.

Commitments, Guarantees and C_3

Commitments, Guarantees and Contingencies (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Contractual Commitments
Less than 1 year		$ 975.5
For 2-3 years		1,006.9
For 4-5 years		489.9
After 5 years		1,310
Total Contractual Commitments		3,782.3
Commitments, Guarantees and Contingencies (Textuals)
Revolving Credit Facilities		4,000
Disposal, Assessed Fees and Related Interest	[1]	281.2	$ 279.8
Asset Retirement Obligation, Period Increase (Decrease)		199
AEP Wind Holdings LLC [Member] | Generation and Marketing [Member]
Commitments, Guarantees and Contingencies (Textuals)
Maximum Potential Amount of Future Payments Associated with Guarantee		157
Guarantor Obligations, Current Carrying Value		31
Guarantor Obligations, Current Carrying Value, Contingent Portion		1
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		179.8
Commitments, Guarantees and Contingencies (Textuals)
Letters of Credit Limit		1,200
Uncommitted Facility		405
Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	[2]	763.9
For 2-3 years	[2]	715.1
For 4-5 years	[2]	212.9
After 5 years	[2]	381.5
Total Contractual Commitments	[2]	2,073.4
Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year		211.6
For 2-3 years		291.8
For 4-5 years		277
After 5 years		928.5
Total Contractual Commitments		1,708.9
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		398.3
For 2-3 years		290.1
For 4-5 years		85.5
After 5 years		246.5
Total Contractual Commitments		1,020.4
Commitments, Guarantees and Contingencies (Textuals)
Asset Retirement Obligation, Period Increase (Decrease)		199
Appalachian Power Co [Member] | Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	[2]	362.8
For 2-3 years	[2]	217.6
For 4-5 years	[2]	11.6
After 5 years	[2]	16.3
Total Contractual Commitments	[2]	608.3
Appalachian Power Co [Member] | Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year		35.5
For 2-3 years		72.5
For 4-5 years		73.9
After 5 years		230.2
Total Contractual Commitments		412.1
Indiana Michigan Power Co [Member]
Contractual Commitments
Less than 1 year		322.9
For 2-3 years		475.6
For 4-5 years		250.2
After 5 years		587.3
Total Contractual Commitments		1,636
Commitments, Guarantees and Contingencies (Textuals)
Disposal, Assessed Fees and Related Interest	[1]	281.2	279.8
Indiana Michigan Power Co [Member] | Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	[2]	157.7
For 2-3 years	[2]	278.9
For 4-5 years	[2]	189.3
After 5 years	[2]	332.7
Total Contractual Commitments	[2]	958.6
Indiana Michigan Power Co [Member] | Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year		165.2
For 2-3 years		196.7
For 4-5 years		60.9
After 5 years		254.6
Total Contractual Commitments		677.4
Ohio Power Co [Member] | Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year		28.8
For 2-3 years		58.2
For 4-5 years		58.1
After 5 years		263.3
Total Contractual Commitments		408.4
Public Service Co Of Oklahoma [Member]
Contractual Commitments
Less than 1 year		114.9
For 2-3 years		113.6
For 4-5 years		66.8
After 5 years		160
Total Contractual Commitments		455.3
Public Service Co Of Oklahoma [Member] | Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	[2]	25.3
For 2-3 years	[2]	36.2
For 4-5 years	[2]	0
After 5 years	[2]	0
Total Contractual Commitments	[2]	61.5
Public Service Co Of Oklahoma [Member] | Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year		89.6
For 2-3 years		77.4
For 4-5 years		66.8
After 5 years		160
Total Contractual Commitments		393.8
Southwestern Electric Power Co [Member]
Contractual Commitments
Less than 1 year		76.8
For 2-3 years		47.6
For 4-5 years		8.4
After 5 years		4.2
Total Contractual Commitments		137
Southwestern Electric Power Co [Member] | Fuel Purchase Contracts [Member]
Contractual Commitments
Less than 1 year	[2]	68.5
For 2-3 years	[2]	39.2
For 4-5 years	[2]	0
After 5 years	[2]	0
Total Contractual Commitments	[2]	107.7
Southwestern Electric Power Co [Member] | Energy and Capacity Purchase Contracts [Member]
Contractual Commitments
Less than 1 year		8.3
For 2-3 years		8.4
For 4-5 years		8.4
After 5 years		4.2
Total Contractual Commitments		29.3
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		4	7	$ 8
Decommissioning Fund Investments, Fair Value		3,000	2,700
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		4	7	8
Decommissioning Fund Investments, Fair Value		3,000	2,700
Spent Nuclear Fuel Disposal [Member]
Commitments, Guarantees and Contingencies (Textuals)
DOE SNF Disposal Fee		0
Disposal, Assessed Fees and Related Interest		281	280
Trust Fund Assets One Time Fee Obligation for Nuclear Fuel Disposition		324	323
Recovery of Spent Nuclear Fuel Storage Costs		24	8	11
Current Amount Recoverable from the Federal Government		14	24
Noncurrent Amount Recoverable from the Federal Government		1	1
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		281	280
Trust Fund Assets One Time Fee Obligation for Nuclear Fuel Disposition		324	323
Recovery of Spent Nuclear Fuel Storage Costs		24	8	$ 11
Current Amount Recoverable from the Federal Government		14	24
Noncurrent Amount Recoverable from the Federal Government		1	$ 1
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		500
Contingent Financial Obligation for Mutual Insurance		42
Insurance Protection for Public Liability Arising from a Nuclear Incident		13,800
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		13,300
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		500
Contingent Financial Obligation for Mutual Insurance		42
Insurance Protection for Public Liability Arising from a Nuclear Incident		13,800
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		13,300
June 2022 [Member] | Letters of Credit [Member]
Commitments, Guarantees and Contingencies (Textuals)
Revolving Credit Facilities		$ 4,000
[1]	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.
[2]	Represents contractual commitments to purchase coal, natural gas, uranium and other consumables as fuel for electric generation along with related transportation of the fuel.

Acquisitions, Dispositions an_3

Acquisitions, Dispositions and Impairments (Details)		1 Months Ended	3 Months Ended															12 Months Ended
		Jun. 30, 2020USD ($)	Dec. 31, 2022USD ($)	Sep. 30, 2022USD ($)	Jun. 30, 2022USD ($)	Mar. 31, 2022USD ($)	Dec. 31, 2021USD ($)	Sep. 30, 2021USD ($)	Jun. 30, 2021USD ($)	Mar. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Sep. 30, 2020USD ($)	Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)MW	Jun. 30, 2019USD ($)RateMW	Sep. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2022USD ($)	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Nov. 30, 2020
Noncash Contribution of Assets by Noncontrolling Interest																				$ 0	$ 0	$ 84,000,000
Noncash or Part Noncash Acquisition, Value of Liabilities Assumed																				0	32,400,000	0
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges																				0	156,400,000	70,600,000
Asset Impairment Charges
Utilities Operating Expense, Operations																				2,572,400,000	2,743,700,000	2,979,200,000
Redeemable Noncontrolling Interest											$ 0		$ 65,700,000							0	65,700,000
Additional Paid in Capital											$ 6,588,900,000		6,535,600,000							6,588,900,000	6,535,600,000
Asset Retirement Obligation, Liabilities Settled	[1],[2],[3],[4]																			$ 188,000,000	118,100,000
Vertically Integrated Utilities [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges																					92,900,000	3,400,000
Generation and Marketing [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges																					31,000,000	47,700,000
Transmission and Distribution Companies [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges																					32,500,000	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																				$ 0	32,500,000	0
Asset Impairment Charges
Utilities Operating Expense, Operations																				488,900,000	492,000,000	488,900,000
Additional Paid in Capital											$ 1,457,900,000		1,457,900,000							1,457,900,000	1,457,900,000
Asset Retirement Obligation, Liabilities Settled	[2],[3]																			8,500,000	200,000
AEP Transmission Co [Member]
Asset Impairment Charges
Utilities Operating Expense, Operations																				99,800,000	93,900,000	83,800,000
Appalachian Power Co [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges																				0	92,900,000	0
Asset Impairment Charges
Utilities Operating Expense, Operations																				530,500,000	567,600,000	511,600,000
Additional Paid in Capital											1,828,700,000		1,828,700,000							1,828,700,000	1,828,700,000
Asset Retirement Obligation, Liabilities Settled	[2],[3]																			7,800,000	17,600,000
Indiana Michigan Power Co [Member]
Cost of Purchased Power from Affiliate																				172,800,000	214,900,000	237,900,000
Asset Impairment Charges
Utilities Operating Expense, Operations																				650,000,000	641,200,000	585,400,000
Additional Paid in Capital											980,900,000		980,900,000							980,900,000	980,900,000
Asset Retirement Obligation, Liabilities Settled	[2],[3],[4]																			200,000	200,000
Ohio Power Co [Member]
Cost of Purchased Power from Affiliate																				119,700,000	156,000,000	135,300,000
Asset Impairment Charges
Utilities Operating Expense, Operations																				822,600,000	742,600,000	771,300,000
Additional Paid in Capital											838,800,000		838,800,000							838,800,000	838,800,000
Asset Retirement Obligation, Liabilities Settled	[2]																			0	300,000
Public Service Co Of Oklahoma [Member]
Asset Impairment Charges
Utilities Operating Expense, Operations																				327,300,000	315,000,000	372,800,000
Additional Paid in Capital											414,000,000		364,000,000							414,000,000	364,000,000
Asset Retirement Obligation, Liabilities Settled	[2],[3]																			3,100,000	400,000
Southwestern Electric Power Co [Member]
Asset Impairment Charges
Utilities Operating Expense, Operations																				338,300,000	348,000,000	$ 384,200,000
Additional Paid in Capital											812,200,000		676,600,000							812,200,000	676,600,000
Asset Retirement Obligation, Liabilities Settled	[1],[2],[3]																			10,900,000	11,800,000
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
Payments for (Proceeds from) Removal Costs		$ 26,000,000									10,000,000	$ 98,000,000
Asset Retirement Obligation, Liabilities Settled												106,000,000
Conesville Generating Station (Unit No. 4) [Member] | Generation and Marketing [Member] | Forecast [Member]
Asset Impairment Charges
Payments for (Proceeds from) Removal Costs			$ 0	$ 5,200,000	$ 9,600,000	$ 9,600,000	$ 9,600,000	$ 9,600,000	$ 9,600,000	$ 9,600,000								$ 24,400,000	$ 38,400,000
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
Asset Impairment Charges
Fair Value of Impaired Assets																$ 0
Trent and Desert Sky Wind Farms [Member] | Generation and Marketing [Member]
Asset Impairment Charges
Payments to Acquire Businesses, Gross												$ 57,000,000
Redeemable Noncontrolling Interest											63,000,000									63,000,000
Additional Paid in Capital											$ 6,000,000									$ 6,000,000
Other Assets [Member] | Corporate and Other [Member]
Disposal Group, Including Discontinued Operation, Income Statement Disclosures
Asset Impairments and Other Related Charges																	$ 21,000,000
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	[5],[6]										70.30%		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	[5],[6]										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	[5],[6]										15.60%		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 | Rate															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											$ 157,000,000									$ 157,000,000
Guarantor Obligations, Current Carrying Value											31,000,000									31,000,000
Guarantor Obligations, Current Carrying Value, Contingent Portion											1,000,000									1,000,000
AEP Wind Holdings LLC [Member] | Indiana Michigan Power Co [Member] | Generation and Marketing [Member]
Cost of Purchased Power from Affiliate																				11,000,000	9,000,000
AEP Wind Holdings LLC [Member] | Ohio Power Co [Member] | Generation and Marketing [Member]
Cost of Purchased Power from Affiliate																				23,000,000	17,000,000
AEP Wind Holdings LLC [Member] | Southwestern Electric Power Co [Member] | Generation and Marketing [Member]
Cost of Purchased Power from Affiliate																				14,000,000	10,000,000
Santa Rita East [Member]
Noncash or Part Noncash Acquisition, Other Assets Acquired																				$ (43,700,000)	$ 118,800,000
Santa Rita East [Member] | Generation and Marketing [Member]
Noncash Contribution of Assets by Noncontrolling Interest											$ 44,000,000
Percentage of an Asset Acquired											85.00%			75.00%						85.00%			10.00%
WindGenerationMWs | MW														227
Asset Impairment Charges
Payments to Acquire Businesses, Gross											$ 44,000,000			$ 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] | 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] | 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
2017-2019 Virginia Triennial Review [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
2017-2019 Virginia Triennial Review [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
[1]	Includes ARO related to Sabine and DHLC.
[2]	Includes ARO related to asbestos removal.
[3]	Includes ARO related to ash disposal facilities.
[4]	Includes ARO related to nuclear decommissioning costs for the Cook Plant of $1.80 billion and $1.73 billion as of December 31, 2020 and 2019, respectively.
[5]	Oklaunion Power Station was retired in September 2020 and sold to a nonaffiliated third-party in October 2020. See the “Dispositions” section of Note 7 for additional information.
[6]	Operated by PSO, which owned 15.6%. Also was jointly-owned (54.7%) by AEP Texas and various nonaffiliated companies.

Benefit Plans 1 (Details)

Benefit Plans 1 (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		$ 3,852.3	$ 3,407.3
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		(728)	(719.8)
AEP Texas Inc. [Member]
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		192.1	147.1
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		(57.2)	(81.1)
Appalachian Power Co [Member]
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		121.7	123.4
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		(49.6)	(55.2)
Indiana Michigan Power Co [Member]
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		237.6	182
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		(69.2)	(67.8)
Ohio Power Co [Member]
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		616.2	546.3
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		(40)	(42.7)
Public Service Co Of Oklahoma [Member]
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		6	4.1
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		(20.6)	(18.4)
Southwestern Electric Power Co [Member]
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		234.8	160.5
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		$ (94.2)	$ (86.2)
Pension Plans [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.50%	3.25%
Interest Crediting Rate		4.00%	4.00%
Rate of Compensation Increase	[1]	5.00%	4.95%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		3.25%	4.30%	3.65%
Interest Crediting Rate		4.00%	4.00%	4.00%
Expected Return on Plan Assets		5.75%	6.25%	6.00%
Rate of Compensation Increase	[2]	5.00%	4.95%	4.85%
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 5,236.8	$ 4,810.3
Service Cost		111.9	95.5	$ 97.6
Interest Cost		167.9	204.4	187.8
Actuarial (Gain) Loss		434.7	493.6
Plan Amendments		0	0.2
Benefit Payments		(406.8)	(367.2)
Participant Contributions		0	0
Medicare Subsidy		0	0
Benefit Obligation as of December 31		5,544.5	5,236.8	4,810.3
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		5,015.4	4,695.9
Actual Gain (Loss) on Plan Assets		832.4	681.1
Company Contributions	[3]	115.6	5.6
Participant Contributions		0	0
Benefit Payments		(406.8)	(367.2)
Fair Value of Plan Assets as of December 31		5,556.6	5,015.4	$ 4,695.9
Funded (Underfunded) Status as of December 31		12.1	(221.4)
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		93.5	0
Other Current Liabilities - Accrued Short-term Benefit Liability		(6.7)	(6.1)
Employee Benefits and Pension Obligations - Accrued Long-term Benefit Liability		(74.7)	(215.3)
Funded (Underfunded) Status		12.1	(221.4)
Components
Net Actuarial Loss		1,179.6	1,406.2
Prior Service Cost (Credit)		0.2	0.2
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(132.9)	108.6
Amortization of Actuarial Gain (Loss)		(93.7)	(57.6)
Prior Service (Credit) Cost		0	0.2
Amortization of Prior Service Credit (Cost)		0	0
Change for the Year		$ (226.6)	$ 51.2
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	[1]	5.00%	4.95%
Company Contributions	[3]	$ 115.6	$ 5.6
Pension Plans [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		1,182.4	1,351.8
Pension Plans [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		(0.5)	11.5
Pension Plans [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		$ (2.1)	$ 43.1
Pension Plans [Member] | AEP Texas Inc. [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.50%	3.25%
Interest Crediting Rate		4.00%	4.00%
Rate of Compensation Increase	[1]	5.05%	5.00%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		3.25%	4.30%	3.65%
Interest Crediting Rate		4.00%	4.00%	4.00%
Expected Return on Plan Assets		5.75%	6.25%	6.00%
Rate of Compensation Increase	[2]	5.05%	5.00%	4.95%
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 441.2	$ 409.3
Service Cost		10	8.6	$ 9.2
Interest Cost		13.9	17.5	16
Actuarial (Gain) Loss		28.1	40.1
Plan Amendments		0	0
Benefit Payments		(40)	(34.3)
Participant Contributions		0	0
Benefit Obligation as of December 31		453.2	441.2	409.3
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		435.1	410.7
Actual Gain (Loss) on Plan Assets		67.2	58.3
Company Contributions		11.7	0.4
Participant Contributions		0	0
Benefit Payments		(40)	(34.3)
Fair Value of Plan Assets as of December 31		474	435.1	$ 410.7
Funded (Underfunded) Status as of December 31		20.8	(6.1)
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		24.7	0
Other Current Liabilities - Accrued Short-term Benefit Liability		(0.4)	(0.4)
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		(3.5)	(5.7)
Funded (Underfunded) Status		20.8	(6.1)
Components
Net Actuarial Loss		160.5	184.7
Prior Service Cost (Credit)		0	0
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(16.4)	7.6
Amortization of Actuarial Gain (Loss)		(7.8)	(4.9)
Prior Service (Credit) Cost		0	0
Amortization of Prior Service Credit (Cost)		0	0
Change for the Year		$ (24.2)	$ 2.7
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	[1]	5.05%	5.00%
Company Contributions		$ 11.7	$ 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		151.3	172.2
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	2.7
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		$ 7.2	$ 9.8
Pension Plans [Member] | Appalachian Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.50%	3.25%
Interest Crediting Rate		4.00%	4.00%
Rate of Compensation Increase	[1]	4.85%	4.80%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		3.25%	4.30%	3.65%
Interest Crediting Rate		4.00%	4.00%	4.00%
Expected Return on Plan Assets		5.75%	6.25%	6.00%
Rate of Compensation Increase	[2]	4.85%	4.75%	4.75%
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 647.2	$ 603.1
Service Cost		10.5	9.4	$ 9.3
Interest Cost		20.3	25.2	23.5
Actuarial (Gain) Loss		40	52.9
Plan Amendments		0	0
Benefit Payments		(47.2)	(43.4)
Participant Contributions		0	0
Medicare Subsidy		0	0
Benefit Obligation as of December 31		670.8	647.2	603.1
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		637	593.3
Actual Gain (Loss) on Plan Assets		104.5	87.1
Company Contributions		7	0
Participant Contributions		0	0
Benefit Payments		(47.2)	(43.4)
Fair Value of Plan Assets as of December 31		701.3	637	$ 593.3
Funded (Underfunded) Status as of December 31		30.5	(10.2)
Benefit Amounts Recognized on the Balance Sheets
Employee Benefits and Pension Assets - Prepaid Benefit Costs		31	0
Other Current Liabilities - Accrued Short-term Benefit Liability		0	0
Employee Benefits and Pension Obligations - Accrued Long-term Benefit Liability		(0.5)	(10.2)
Funded (Underfunded) Status		30.5	(10.2)
Components
Net Actuarial Loss		126.3	168.3
Prior Service Cost (Credit)		0	0
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(30.8)	3.1
Amortization of Actuarial Gain (Loss)		(11.2)	(7)
Prior Service (Credit) Cost		0	0
Amortization of Prior Service Credit (Cost)		0	0
Change for the Year		$ (42)	$ (3.9)
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	[1]	4.85%	4.80%
Company Contributions		$ 7	$ 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		124.7	166.3
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	0.3
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		$ 1.3	$ 1.7
Pension Plans [Member] | Indiana Michigan Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.50%	3.25%
Interest Crediting Rate		4.00%	4.00%
Rate of Compensation Increase	[1]	5.00%	4.95%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		3.25%	4.30%	3.65%
Interest Crediting Rate		4.00%	4.00%	4.00%
Expected Return on Plan Assets		5.75%	6.25%	6.00%
Rate of Compensation Increase	[2]	5.00%	4.95%	4.90%
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 616.1	$ 567
Service Cost		15.4	13.4	$ 13.6
Interest Cost		19.7	23.8	22.1
Actuarial (Gain) Loss		44.3	49.8
Plan Amendments		0	0
Benefit Payments		(42.2)	(37.9)
Participant Contributions		0	0
Benefit Obligation as of December 31		653.3	616.1	567
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		630.5	583.8
Actual Gain (Loss) on Plan Assets		103.3	84.6
Company Contributions		6.5	0
Participant Contributions		0	0
Benefit Payments		(42.2)	(37.9)
Fair Value of Plan Assets as of December 31		698.1	630.5	$ 583.8
Funded (Underfunded) Status as of December 31		44.8	14.4
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		46.5	15.8
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		(1.7)	(1.4)
Funded (Underfunded) Status		44.8	14.4
Components
Net Actuarial Loss		39.5	76
Prior Service Cost (Credit)		0	0
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(25.7)	2
Amortization of Actuarial Gain (Loss)		(10.8)	(6.6)
Prior Service (Credit) Cost		0	0
Amortization of Prior Service Credit (Cost)		0	0
Change for the Year		$ (36.5)	$ (4.6)
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	[1]	5.00%	4.95%
Company Contributions		$ 6.5	$ 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		40.3	73.7
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		(0.1)	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		$ (0.7)	$ 1.8
Pension Plans [Member] | Ohio Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.50%	3.25%
Interest Crediting Rate		4.00%	4.00%
Rate of Compensation Increase	[1]	5.25%	5.15%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		3.25%	4.30%	3.65%
Interest Crediting Rate		4.00%	4.00%	4.00%
Expected Return on Plan Assets		5.75%	6.25%	6.00%
Rate of Compensation Increase	[2]	5.25%	5.20%	5.00%
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 487.8	$ 453.9
Service Cost		9.7	7.9	$ 7.7
Interest Cost		15.4	19.1	17.7
Actuarial (Gain) Loss		33.4	40.5
Plan Amendments		0	0
Benefit Payments		(36)	(33.6)
Participant Contributions		0	0
Medicare Subsidy		0	0
Benefit Obligation as of December 31		510.3	487.8	453.9
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		499.1	466.1
Actual Gain (Loss) on Plan Assets		79.9	66.6
Company Contributions		0.1	0
Participant Contributions		0	0
Benefit Payments		(36)	(33.6)
Fair Value of Plan Assets as of December 31		543.1	499.1	$ 466.1
Funded (Underfunded) Status as of December 31		32.8	11.3
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		33.3	11.7
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		(0.5)	(0.4)
Funded (Underfunded) Status		32.8	11.3
Components
Net Actuarial Loss		150	178.7
Prior Service Cost (Credit)		0	0
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(20.2)	3.3
Amortization of Actuarial Gain (Loss)		(8.5)	(5.3)
Prior Service (Credit) Cost		0	0
Amortization of Prior Service Credit (Cost)		0	0
Change for the Year		$ (28.7)	$ (2)
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	[1]	5.25%	5.15%
Company Contributions		$ 0.1	$ 0
Pension Plans [Member] | Ohio Power Co [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		$ 150	$ 178.7
Pension Plans [Member] | Public Service Co Of Oklahoma [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.50%	3.25%
Interest Crediting Rate		4.00%	4.00%
Rate of Compensation Increase	[1]	5.05%	5.05%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		3.25%	4.30%	3.65%
Interest Crediting Rate		4.00%	4.00%	4.00%
Expected Return on Plan Assets		5.75%	6.25%	6.00%
Rate of Compensation Increase	[2]	5.05%	5.05%	4.90%
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 267.5	$ 253.8
Service Cost		7.3	6.5	$ 7
Interest Cost		8.5	10.6	9.9
Actuarial (Gain) Loss		17.7	16.8
Plan Amendments		0	0
Benefit Payments		(21.1)	(20.2)
Participant Contributions		0	0
Benefit Obligation as of December 31		279.9	267.5	253.8
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		276.2	261.2
Actual Gain (Loss) on Plan Assets		44.6	34.7
Company Contributions		0.1	0.5
Participant Contributions		0	0
Benefit Payments		(21.1)	(20.2)
Fair Value of Plan Assets as of December 31		299.8	276.2	$ 261.2
Funded (Underfunded) Status as of December 31		19.9	8.7
Benefit Amounts Recognized on the Balance Sheets
Employee Benefits and Pension Assets - Prepaid Benefit Costs		21.9	10.6
Other Current Liabilities - Accrued Short-term Benefit Liability		(0.1)	(0.1)
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		(1.9)	(1.8)
Funded (Underfunded) Status		19.9	8.7
Components
Net Actuarial Loss		55.9	73
Prior Service Cost (Credit)		0	0
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(12.4)	(1.7)
Amortization of Actuarial Gain (Loss)		(4.7)	(2.9)
Prior Service (Credit) Cost		0	0
Amortization of Prior Service Credit (Cost)		0	0
Change for the Year		$ (17.1)	$ (4.6)
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	[1]	5.05%	5.05%
Company Contributions		$ 0.1	$ 0.5
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		$ 55.9	$ 73
Pension Plans [Member] | Southwestern Electric Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.50%	3.25%
Interest Crediting Rate		4.00%	4.00%
Rate of Compensation Increase	[1]	4.90%	4.90%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		3.25%	4.30%	3.65%
Interest Crediting Rate		4.00%	4.00%	4.00%
Expected Return on Plan Assets		5.75%	6.25%	6.00%
Rate of Compensation Increase	[2]	4.90%	4.90%	4.85%
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 314.2	$ 291.4
Service Cost		9.9	8.6	$ 9.3
Interest Cost		10.2	12.4	11.3
Actuarial (Gain) Loss		27.4	25.5
Plan Amendments		0	0
Benefit Payments		(27.2)	(23.7)
Participant Contributions		0	0
Benefit Obligation as of December 31		334.5	314.2	291.4
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		296.9	281
Actual Gain (Loss) on Plan Assets		48.2	39.5
Company Contributions		9	0.1
Participant Contributions		0	0
Benefit Payments		(27.2)	(23.7)
Fair Value of Plan Assets as of December 31		326.9	296.9	$ 281
Funded (Underfunded) Status as of December 31		(7.6)	(17.3)
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)	(0.1)
Employee Benefits and Pension Obligations - Accrued Long-term Benefit Liability		(7.5)	(17.2)
Funded (Underfunded) Status		(7.6)	(17.3)
Components
Net Actuarial Loss		86.9	97.8
Prior Service Cost (Credit)		0	0
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(5.2)	3.8
Amortization of Actuarial Gain (Loss)		(5.7)	(3.4)
Prior Service (Credit) Cost		0	0
Amortization of Prior Service Credit (Cost)		0	0
Change for the Year		$ (10.9)	$ 0.4
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	[1]	4.90%	4.90%
Company Contributions		$ 9	$ 0.1
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		86.9	97.8
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%
Qualified Pension Plans [Member]
Change in Fair Value of Plan Assets
Company Contributions		$ 110	0
Benefit Plans (Textuals) [Abstract]
Company Contributions		110	0
Nonqualified Pension Plans [Member]
Change in Benefit Obligation
Benefit Obligation as of December 31		81.4
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		0
Company Contributions		6	6
Fair Value of Plan Assets as of December 31		0	0
Benefit Plans (Textuals) [Abstract]
Company Contributions		6	6
Nonqualified Pension Plans [Member] | AEP Texas Inc. [Member]
Change in Benefit Obligation
Benefit Obligation as of December 31		3.9
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 Benefit Obligation
Benefit Obligation as of December 31		0.5
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		1.5
Benefit Obligation as of December 31		1.7	1.5
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		0.6	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		1.9
Benefit Obligation as of December 31		2	1.9
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		2.55%	3.30%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		3.30%	4.30%	3.60%
Expected Return on Plan Assets		5.50%	6.25%	6.00%
Health Care Trend Rates
Initial		6.50%	6.00%
Ultimate		4.50%	4.50%
Year Ultimate Reached		2029	2026
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 1,225.4	$ 1,194.5
Service Cost		10	9.5	$ 11.6
Interest Cost		39.8	50.5	47.4
Actuarial (Gain) Loss		39.3	58.8
Plan Amendments		(11.4)	(11)
Benefit Payments		(131)	(113)
Participant Contributions		38.2	35.5
Medicare Subsidy		0.6	0.6
Benefit Obligation as of December 31		1,210.9	1,225.4	1,194.5
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		1,781.8	1,534.2
Actual Gain (Loss) on Plan Assets		253	321
Company Contributions	[3]	4.7	4.1
Participant Contributions		38.2	35.5
Benefit Payments		(131)	(113)
Fair Value of Plan Assets as of December 31		1,946.7	1,781.8	$ 1,534.2
Funded (Underfunded) Status as of December 31		735.8	556.4
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		771.9	590.8
Other Current Liabilities - Accrued Short-term Benefit Liability		(2.4)	(2.6)
Employee Benefits and Pension Obligations - Accrued Long-term Benefit Liability		(33.7)	(31.8)
Funded (Underfunded) Status		735.8	556.4
Components
Net Actuarial Loss		101.9	225.8
Prior Service Cost (Credit)		(227.3)	(285.7)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(118)	(171.9)
Amortization of Actuarial Gain (Loss)		(5.9)	(22.1)
Prior Service (Credit) Cost		(11.4)	(7.6)
Amortization of Prior Service Credit (Cost)		69.8	69.1
Change for the Year		(65.5)	(132.5)
Benefit Plans (Textuals) [Abstract]
Company Contributions	[3]	4.7	4.1
Other Postretirement Benefit Plans [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		(99)	(46.8)
Other Postretirement Benefit Plans [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		(5.5)	(2.7)
Other Postretirement Benefit Plans [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		$ (20.9)	$ (10.4)
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.55%	3.30%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		3.30%	4.30%	3.60%
Expected Return on Plan Assets		5.50%	6.25%	6.00%
Health Care Trend Rates
Initial		6.50%	6.00%
Ultimate		4.50%	4.50%
Year Ultimate Reached		2029	2026
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 97.8	$ 95.9
Service Cost		0.8	0.8	$ 0.9
Interest Cost		3.2	4	3.8
Actuarial (Gain) Loss		2.4	3.9
Plan Amendments		(1)	(0.9)
Benefit Payments		(10)	(8.8)
Participant Contributions		3.1	2.9
Benefit Obligation as of December 31		96.3	97.8	95.9
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		148.1	129.9
Actual Gain (Loss) on Plan Assets		21.1	24
Company Contributions		0	0.1
Participant Contributions		3.1	2.9
Benefit Payments		(10)	(8.8)
Fair Value of Plan Assets as of December 31		162.3	148.1	$ 129.9
Funded (Underfunded) Status as of December 31		66	50.3
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		66	50.3
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		66	50.3
Components
Net Actuarial Loss		12.3	23.5
Prior Service Cost (Credit)		(19.3)	(24.2)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(10.7)	(12.7)
Amortization of Actuarial Gain (Loss)		(0.5)	(1.8)
Prior Service (Credit) Cost		(1)	(0.6)
Amortization of Prior Service Credit (Cost)		5.9	5.9
Change for the Year		(6.3)	(9.2)
Benefit Plans (Textuals) [Abstract]
Company Contributions		0	0.1
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		(6.3)	(0.2)
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)	(0.1)
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		$ (0.6)	$ (0.4)
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.55%	3.30%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		3.30%	4.30%	3.60%
Expected Return on Plan Assets		5.50%	6.25%	6.00%
Health Care Trend Rates
Initial		6.50%	6.00%
Ultimate		4.50%	4.50%
Year Ultimate Reached		2029	2026
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 203.5	$ 205.5
Service Cost		1	1	$ 1.1
Interest Cost		6.6	8.7	8.2
Actuarial (Gain) Loss		5.6	4.7
Plan Amendments		(1.8)	(1.7)
Benefit Payments		(23.2)	(20.8)
Participant Contributions		6.3	5.9
Medicare Subsidy		0.2	0.2
Benefit Obligation as of December 31		198.2	203.5	205.5
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		271	238.4
Actual Gain (Loss) on Plan Assets		36.8	45.3
Company Contributions		2.1	2.2
Participant Contributions		6.3	5.9
Benefit Payments		(23.2)	(20.8)
Fair Value of Plan Assets as of December 31		293	271	$ 238.4
Funded (Underfunded) Status as of December 31		94.8	67.5
Benefit Amounts Recognized on the Balance Sheets
Employee Benefits and Pension Assets - Prepaid Benefit Costs		119.1	92
Other Current Liabilities - Accrued Short-term Benefit Liability		(1.8)	(2)
Employee Benefits and Pension Obligations - Accrued Long-term Benefit Liability		(22.5)	(22.5)
Funded (Underfunded) Status		94.8	67.5
Components
Net Actuarial Loss		11.1	28.8
Prior Service Cost (Credit)		(33.2)	(41.6)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(16.8)	(26.4)
Amortization of Actuarial Gain (Loss)		(0.9)	(3.7)
Prior Service (Credit) Cost		(1.8)	(1.3)
Amortization of Prior Service Credit (Cost)		10.2	10.1
Change for the Year		(9.3)	(21.3)
Benefit Plans (Textuals) [Abstract]
Company Contributions		2.1	2.2
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		(10.3)	(5.5)
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		(2.5)	(1.5)
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		$ (9.3)	$ (5.8)
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.55%	3.30%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		3.30%	4.30%	3.60%
Expected Return on Plan Assets		5.50%	6.25%	6.00%
Health Care Trend Rates
Initial		6.50%	6.00%
Ultimate		4.50%	4.50%
Year Ultimate Reached		2029	2026
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 142.9	$ 138.3
Service Cost		1.4	1.4	$ 1.6
Interest Cost		4.7	5.8	5.4
Actuarial (Gain) Loss		5.1	8.1
Plan Amendments		(1.6)	(1.5)
Benefit Payments		(15.9)	(13.6)
Participant Contributions		4.8	4.4
Benefit Obligation as of December 31		141.4	142.9	138.3
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		216.3	187.3
Actual Gain (Loss) on Plan Assets		33	38.2
Company Contributions		0	0
Participant Contributions		4.8	4.4
Benefit Payments		(15.9)	(13.6)
Fair Value of Plan Assets as of December 31		238.2	216.3	$ 187.3
Funded (Underfunded) Status as of December 31		96.8	73.4
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		96.8	73.4
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		0	0
Funded (Underfunded) Status		96.8	73.4
Components
Net Actuarial Loss		15.6	32.7
Prior Service Cost (Credit)		(31)	(39)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(16.4)	(19.3)
Amortization of Actuarial Gain (Loss)		(0.7)	(2.7)
Prior Service (Credit) Cost		(1.5)	(1)
Amortization of Prior Service Credit (Cost)		9.5	9.4
Change for the Year		(9.1)	(13.6)
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		(14.6)	(6.2)
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		(0.2)	0
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		$ (0.6)	$ (0.1)
Other Postretirement Benefit Plans [Member] | Ohio Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.55%	3.30%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		3.30%	4.30%	3.60%
Expected Return on Plan Assets		5.50%	6.25%	6.00%
Health Care Trend Rates
Initial		6.50%	6.00%
Ultimate		4.50%	4.50%
Year Ultimate Reached		2029	2026
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 130.2	$ 129.5
Service Cost		0.9	0.8	$ 0.9
Interest Cost		4.2	5.5	5.1
Actuarial (Gain) Loss		3.1	4.9
Plan Amendments		(1.3)	(1.2)
Benefit Payments		(15)	(13.5)
Participant Contributions		4.3	4.1
Medicare Subsidy		0	0.1
Benefit Obligation as of December 31		126.4	130.2	129.5
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		197.1	175.4
Actual Gain (Loss) on Plan Assets		26.6	31.1
Company Contributions		0	0
Participant Contributions		4.3	4.1
Benefit Payments		(15)	(13.5)
Fair Value of Plan Assets as of December 31		213	197.1	$ 175.4
Funded (Underfunded) Status as of December 31		86.6	66.9
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		86.6	66.9
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		0	0
Funded (Underfunded) Status		86.6	66.9
Components
Net Actuarial Loss		3.6	17.2
Prior Service Cost (Credit)		(22.9)	(28.6)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(12.9)	(15.8)
Amortization of Actuarial Gain (Loss)		(0.7)	(2.5)
Prior Service (Credit) Cost		(1.3)	(0.8)
Amortization of Prior Service Credit (Cost)		7	6.9
Change for the Year		(7.9)	(12.2)
Benefit Plans (Textuals) [Abstract]
Company Contributions		0	0
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		$ (19.3)	$ (11.4)
Other Postretirement Benefit Plans [Member] | Public Service Co Of Oklahoma [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.55%	3.30%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		3.30%	4.30%	3.60%
Expected Return on Plan Assets		5.50%	6.25%	6.00%
Health Care Trend Rates
Initial		6.50%	6.00%
Ultimate		4.50%	4.50%
Year Ultimate Reached		2029	2026
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 64.7	$ 62.3
Service Cost		0.7	0.6	$ 0.7
Interest Cost		2.1	2.6	2.5
Actuarial (Gain) Loss		1.9	3.8
Plan Amendments		(0.7)	(0.7)
Benefit Payments		(6.8)	(5.9)
Participant Contributions		2.1	2
Benefit Obligation as of December 31		64	64.7	62.3
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		98	84.3
Actual Gain (Loss) on Plan Assets		14.5	17.6
Company Contributions		0	0
Participant Contributions		2.1	2
Benefit Payments		(6.8)	(5.9)
Fair Value of Plan Assets as of December 31		107.8	98	$ 84.3
Funded (Underfunded) Status as of December 31		43.8	33.3
Benefit Amounts Recognized on the Balance Sheets
Employee Benefits and Pension Assets - Prepaid Benefit Costs		43.8	33.3
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		43.8	33.3
Components
Net Actuarial Loss		10.5	18.2
Prior Service Cost (Credit)		(14.1)	(17.8)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(7.4)	(8.9)
Amortization of Actuarial Gain (Loss)		(0.3)	(1.2)
Prior Service (Credit) Cost		(0.7)	(0.5)
Amortization of Prior Service Credit (Cost)		4.4	4.3
Change for the Year		(4)	(6.3)
Benefit Plans (Textuals) [Abstract]
Company Contributions		0	0
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		$ (3.6)	$ 0.4
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.55%	3.30%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		3.30%	4.30%	3.60%
Expected Return on Plan Assets		5.50%	6.25%	6.00%
Health Care Trend Rates
Initial		6.50%	6.00%
Ultimate		4.50%	4.50%
Year Ultimate Reached		2029	2026
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 77.4	$ 72.7
Service Cost		0.8	0.8	$ 0.9
Interest Cost		2.5	3.1	2.8
Actuarial (Gain) Loss		2.5	6
Plan Amendments		(0.8)	(0.8)
Benefit Payments		(7.7)	(6.6)
Participant Contributions		2.4	2.2
Benefit Obligation as of December 31		77.1	77.4	72.7
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		117.2	98.5
Actual Gain (Loss) on Plan Assets		18	23.1
Company Contributions		0	0
Participant Contributions		2.4	2.2
Benefit Payments		(7.7)	(6.6)
Fair Value of Plan Assets as of December 31		129.9	117.2	$ 98.5
Funded (Underfunded) Status as of December 31		52.8	39.8
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		52.8	39.8
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		52.8	39.8
Components
Net Actuarial Loss		11.5	21.1
Prior Service Cost (Credit)		(17.2)	(21.6)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(9.2)	(11.4)
Amortization of Actuarial Gain (Loss)		(0.4)	(1.4)
Prior Service (Credit) Cost		(0.8)	(0.6)
Amortization of Prior Service Credit (Cost)		5.2	5.2
Change for the Year		(5.2)	(8.2)
Benefit Plans (Textuals) [Abstract]
Company Contributions		0	0
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		(3)	0
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		(0.5)	0
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		$ (2.2)	$ (0.5)
[1]	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.
[2]	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.
[3]	Contributions to the qualified pension plan were $110 million and $0 for the years ended December 31, 2020 and 2019, respectively. Contributions to the non-qualified pension plans were $6 million and $6 million for the years ended December 31, 2020 and 2019, respectively.

Benefit Plans 2 (Details)

Benefit Plans 2 (Details) - USD ($) $ in Millions		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		$ 5,556.6	$ 5,015.4	$ 4,695.9
Year End Allocation
Total		100.00%	100.00%
Pension Plan [Member] | AEP Texas Inc. [Member]
Allocated Assets of Investments		8.50%	8.70%
Pension and Other Postretirement Plans' Assets
Asset Class		$ 474	$ 435.1	410.7
Pension Plan [Member] | Appalachian Power Co [Member]
Allocated Assets of Investments		12.60%	12.70%
Pension and Other Postretirement Plans' Assets
Asset Class		$ 701.3	$ 637	593.3
Pension Plan [Member] | Indiana Michigan Power Co [Member]
Allocated Assets of Investments		12.60%	12.60%
Pension and Other Postretirement Plans' Assets
Asset Class		$ 698.1	$ 630.5	583.8
Pension Plan [Member] | Ohio Power Co [Member]
Allocated Assets of Investments		9.80%	10.00%
Pension and Other Postretirement Plans' Assets
Asset Class		$ 543.1	$ 499.1	466.1
Pension Plan [Member] | Public Service Co Of Oklahoma [Member]
Allocated Assets of Investments		5.40%	5.50%
Pension and Other Postretirement Plans' Assets
Asset Class		$ 299.8	$ 276.2	261.2
Pension Plan [Member] | Southwestern Electric Power Co [Member]
Allocated Assets of Investments		5.90%	5.90%
Pension and Other Postretirement Plans' Assets
Asset Class		$ 326.9	$ 296.9	281
Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		$ 1,946.7	$ 1,781.8	1,534.2
Year End Allocation
Total		100.00%	100.00%
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member]
Allocated Assets of Investments		8.30%	8.30%
Pension and Other Postretirement Plans' Assets
Asset Class		$ 162.3	$ 148.1	129.9
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member]
Allocated Assets of Investments		15.10%	15.20%
Pension and Other Postretirement Plans' Assets
Asset Class		$ 293	$ 271	238.4
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member]
Allocated Assets of Investments		12.20%	12.10%
Pension and Other Postretirement Plans' Assets
Asset Class		$ 238.2	$ 216.3	187.3
Other Postretirement Benefit Plans [Member] | Ohio Power Co [Member]
Allocated Assets of Investments		10.90%	11.10%
Pension and Other Postretirement Plans' Assets
Asset Class		$ 213	$ 197.1	175.4
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		$ 107.8	$ 98	84.3
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member]
Allocated Assets of Investments		6.70%	6.60%
Pension and Other Postretirement Plans' Assets
Asset Class		$ 129.9	$ 117.2	$ 98.5
Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		1,460.2	1,337.3
Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		459	449.3
Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		1,217.2	991.1
Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		790.6	649.1
Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		2,879.2	2,687
Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		697.1	683.4
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]	$ 1,868.6	$ 1,544.2
Year End Allocation
Total	[1]	33.60%	30.80%
Equity Securities [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		$ 955.3	$ 824.5
Year End Allocation
Total		49.10%	46.30%
Equity Securities [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	$ 650	$ 547.3
Equity Securities [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		264.7	260.8
Equity Securities [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	1,218.6	996.9
Equity Securities [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		690.6	563.7
Equity Securities [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	0	0
Equity Securities [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		0	0
Equity Securities [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	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	[1]	$ 542.3	$ 387.8
Year End Allocation
Total	[1]	9.70%	7.80%
Domestic [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		$ 399.9	$ 312.2
Year End Allocation
Total		20.60%	17.50%
Domestic [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	$ 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	[1]	542.3	387.8
Domestic [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		399.9	312.2
Domestic [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	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	[1]	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	[1]	$ 676.3	$ 609.1
Year End Allocation
Total	[1]	12.20%	12.10%
International [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		$ 290.7	$ 251.5
Year End Allocation
Total		14.90%	14.10%
International [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	$ 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	[1]	676.3	609.1
International [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		290.7	251.5
International [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	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	[1]	0	0
International [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		0	0
Common Collective Trusts [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1],[2]	$ 650	$ 547.3
Year End Allocation
Total	[1],[2]	11.70%	10.90%
Common Collective Trusts [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[3]	$ 264.7	$ 260.8
Year End Allocation
Total	[3]	13.60%	14.70%
Common Collective Trusts [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1],[2]	$ 650	$ 547.3
Common Collective Trusts [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[3]	264.7	260.8
Common Collective Trusts [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1],[2]	0	0
Common Collective Trusts [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[3]	0	0
Common Collective Trusts [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1],[2]	0	0
Common Collective Trusts [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[3]	0	0
Common Collective Trusts [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1],[2]	0	0
Common Collective Trusts [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[3]	0	0
Fixed Income [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	$ 2,828.5	$ 2,656.8
Year End Allocation
Total	[1]	50.90%	53.00%
Fixed Income [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		$ 756.5	$ 707.9
Year End Allocation
Total		38.90%	39.70%
Fixed Income [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	$ 0	$ 0
Fixed Income [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		186.4	177.6
Fixed Income [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	(1.4)	(5.8)
Fixed Income [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		73.7	58.7
Fixed Income [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	2,829.9	2,662.6
Fixed Income [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		496.4	471.6
Fixed Income [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	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	[3]	$ 186.4	$ 177.6
Year End Allocation
Total	[3]	9.60%	10.00%
Common Collective Trust - Debt [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[3]	$ 186.4	$ 177.6
Common Collective Trust - Debt [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[3]	0	0
Common Collective Trust - Debt [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[3]	0	0
Common Collective Trust - Debt [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[3]	0	0
United States Government and Agency Securities [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	$ 1,132.7	$ 1,242.8
Year End Allocation
Total	[1]	20.40%	24.80%
United States Government and Agency Securities [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		$ 199.5	$ 214.3
Year End Allocation
Total		10.20%	12.00%
United States Government and Agency Securities [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	$ 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	[1]	(1.4)	(5.8)
United States Government and Agency Securities [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		(0.2)	(0.1)
United States Government and Agency Securities [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	1,134.1	1,248.6
United States Government and Agency Securities [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		199.7	214.4
United States Government and Agency Securities [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	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]	$ 1,425	$ 1,143.7
Year End Allocation
Total	[1]	25.60%	22.80%
Corporate Debt [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		$ 248.7	$ 206.7
Year End Allocation
Total		12.80%	11.60%
Corporate Debt [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	$ 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	[1]	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]	1,425	1,143.7
Corporate Debt [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		248.7	206.7
Corporate Debt [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	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	[1]	$ 214	$ 211.6
Year End Allocation
Total	[1]	3.90%	4.20%
Foreign Debt [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		$ 34.9	$ 35.5
Year End Allocation
Total		1.80%	2.00%
Foreign Debt [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	$ 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	[1]	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	[1]	214	211.6
Foreign Debt [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		34.9	35.5
Foreign Debt [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	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	[1]	$ 56	$ 55.1
Year End Allocation
Total	[1]	1.00%	1.10%
State and Local Government [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		$ 87	$ 73.6
Year End Allocation
Total		4.50%	4.10%
State and Local Government [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	$ 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	[1]	0	0
State and Local Government [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		73.9	58.8
State and Local Government [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	56	55.1
State and Local Government [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		13.1	14.8
State and Local Government [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	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	[1]	$ 0.8	$ 3.6
Year End Allocation
Total	[1]	0.00%	0.10%
Other - Asset Backed [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class			$ 0.2
Year End Allocation
Total			0.00%
Other - Asset Backed [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	$ 0	$ 0
Other - Asset Backed [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class			0
Other - Asset Backed [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	0	0
Other - Asset Backed [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class			0
Other - Asset Backed [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	0.8	3.6
Other - Asset Backed [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class			0.2
Other - Asset Backed [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[1]	0	0
Other - Asset Backed [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class			0
Infrastructure [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[2]	$ 91.1	$ 85.8
Year End Allocation
Total	[2]	1.60%	1.70%
Infrastructure [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[2]	$ 91.1	$ 85.8
Infrastructure [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[2]	0	0
Infrastructure [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[2]	0	0
Infrastructure [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[2]	0	0
Real Estate [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[2]	$ 231.6	$ 239.4
Year End Allocation
Total	[2]	4.20%	4.80%
Real Estate [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[2]	$ 231.6	$ 239.4
Real Estate [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[2]	0	0
Real Estate [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[2]	0	0
Real Estate [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[2]	0	0
Alternative Investments [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[2]	$ 431.8	$ 448.3
Year End Allocation
Total	[2]	7.80%	8.90%
Alternative Investments [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[2]	$ 431.8	$ 448.3
Alternative Investments [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[2]	0	0
Alternative Investments [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[2]	0	0
Alternative Investments [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[2]	0	0
Trusted Owned Life Insurance [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class		$ 200.7	$ 211.8
Year End Allocation
Total		10.30%	11.90%
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		200.7	211.8
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		$ 64.8	$ 60.2
Year End Allocation
Total		3.30%	3.40%
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		64.8	60.2
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		$ 135.9	$ 151.6
Year End Allocation
Total		7.00%	8.50%
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		135.9	151.6
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	[2]	$ 107.5	$ 61.6
Year End Allocation
Total	[2]	1.90%	1.20%
Cash and Cash Equivalents [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[3]	$ 32	$ 33.4
Year End Allocation
Total	[3]	1.60%	1.90%
Cash and Cash Equivalents [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[2]	$ 58.2	$ 37.2
Cash and Cash Equivalents [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[3]	5.7	6.7
Cash and Cash Equivalents [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[2]	0	0
Cash and Cash Equivalents [Member] | Level 1 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[3]	26.3	26.7
Cash and Cash Equivalents [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[2]	49.3	24.4
Cash and Cash Equivalents [Member] | Level 2 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[3]	0	0
Cash and Cash Equivalents [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[2]	0	0
Cash and Cash Equivalents [Member] | Level 3 [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[3]	0	0
Other - Pending Transactions and Accrued Income [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[4]	$ (2.5)	$ (20.7)
Year End Allocation
Total	[4]	0.00%	(0.40%)
Other - Pending Transactions and Accrued Income [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[5]	$ 2.2	$ 4.2
Year End Allocation
Total	[5]	0.10%	0.20%
Other - Pending Transactions and Accrued Income [Member] | Other [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[4]	$ (2.5)	$ (20.7)
Other - Pending Transactions and Accrued Income [Member] | Other [Member] | Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[5]	2.2	4.2
Other - Pending Transactions and Accrued Income [Member] | Level 1 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[4]	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	[5]	0	0
Other - Pending Transactions and Accrued Income [Member] | Level 2 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[4]	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	[5]	0	0
Other - Pending Transactions and Accrued Income [Member] | Level 3 [Member] | Pension Plan [Member]
Pension and Other Postretirement Plans' Assets
Asset Class	[4]	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	[5]	$ 0	$ 0
[1]	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.
[2]	Amounts in “Other” column represent investments for which fair value is measured using net asset value per-share.
[3]	Amounts in “Other” column represent investments for which fair value is measured using net asset value per-share.
[4]	Amounts in “Other” column primarily represent accrued interest, dividend receivables and transactions pending settlement.
[5]	Amounts in “Other” column primarily represent accrued interest, dividend receivables and transactions pending settlement.

Benefit Plans 3 (Details)

Benefit Plans 3 (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
American Electric Power System Retirement Savings Plans
Cost of Company Matching Contributions	$ 81.8	$ 76.4	$ 71.8
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	$ 25	20
Noncurrent Regulatory Assets	3,527	3,158.8
Noncurrent Regulatory Liabilities	8,378.7	8,457.6
UMWA Withdrawal Obligation [Member]
Benefit Plans Textuals [Abstract]
Noncurrent Regulatory Assets	6	2
AEP Texas Inc. [Member]
American Electric Power System Retirement Savings Plans
Cost of Company Matching Contributions	$ 6.4	5.9	5.7
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	$ 266.8	280.6
Noncurrent Regulatory Liabilities	1,270.8	1,316.9
Appalachian Power Co [Member]
American Electric Power System Retirement Savings Plans
Cost of Company Matching Contributions	$ 7.7	7.5	7.5
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	$ 686.3	457.2
Noncurrent Regulatory Liabilities	1,224.7	1,268.7
Indiana Michigan Power Co [Member]
American Electric Power System Retirement Savings Plans
Cost of Company Matching Contributions	$ 11.3	11	10.5
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	$ 404.8	482.1
Noncurrent Regulatory Liabilities	2,041.9	1,891.4
Ohio Power Co [Member]
American Electric Power System Retirement Savings Plans
Cost of Company Matching Contributions	$ 7.3	6.6	6.3
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	$ 385.8	351.8
Noncurrent Regulatory Liabilities	1,005.2	1,090.9
Public Service Co Of Oklahoma [Member]
American Electric Power System Retirement Savings Plans
Cost of Company Matching Contributions	$ 4.9	4.6	4.5
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	375.2
Noncurrent Regulatory Liabilities	802.2	837.2
Southwestern Electric Power Co [Member]
American Electric Power System Retirement Savings Plans
Cost of Company Matching Contributions	$ 6.7	6.2	5.9
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	$ 403.1	222.4
Noncurrent Regulatory Liabilities	863.4	892.3
Pension Plans [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	5,244.2	4,998.7
Underfunded Benefit Obligation
Projected Benefit Obligation	5,544.5	5,236.8	4,810.3
Accumulated Benefit Obligation	5,244.2	4,998.7
Fair Value of Plan Assets	5,556.6	5,015.4	4,695.9
Underfunded Status, Projected Benefit Obligation		(221.4)
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2021	132.8
Components of Net Periodic Benefit Cost
Service Cost	111.9	95.5	97.6
Interest Cost	167.9	204.4	187.8
Expected Return on Plan Assets	(264.9)	(296)	(290.3)
Amortization of Prior Service Cost (Credit)	0	0	0
Amortization of Net Actuarial Loss	93.7	57.6	85.2
Settlements	0	0	2.6
Net Periodic Benefit Cost (Credit)	108.6	61.5	82.9
Capitalized Portion	(47)	(38.6)	(41.1)
Net Periodic Benefit Cost (Credit) Recognized in Expense	61.6	22.9	41.8
Pension Plans [Member] | Pension Payments [Member]
Estimated Future Benefit Payments and Contributions
2021	385.3
2022	382.8
2023	384.3
2024	384
2025	377.1
Years 2026 to 2030, in Total	1,763.1
Pension Plans [Member] | AEP Texas Inc. [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	428.1	421.1
Underfunded Benefit Obligation
Projected Benefit Obligation	453.2	441.2	409.3
Accumulated Benefit Obligation	428.1	421.1
Fair Value of Plan Assets	474	435.1	410.7
Underfunded Status, Projected Benefit Obligation		(6.1)
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2021	5.1
Components of Net Periodic Benefit Cost
Service Cost	10	8.6	9.2
Interest Cost	13.9	17.5	16
Expected Return on Plan Assets	(22.7)	(25.8)	(25.6)
Amortization of Prior Service Cost (Credit)	0	0	0
Amortization of Net Actuarial Loss	7.8	4.9	7.2
Net Periodic Benefit Cost (Credit)	9	5.2	6.8
Capitalized Portion	(5.5)	(4.5)	(4.8)
Net Periodic Benefit Cost (Credit) Recognized in Expense	3.5	0.7	2
Pension Plans [Member] | AEP Texas Inc. [Member] | Pension Payments [Member]
Estimated Future Benefit Payments and Contributions
2021	36.3
2022	35.9
2023	36.1
2024	35.9
2025	35.2
Years 2026 to 2030, in Total	154.1
Pension Plans [Member] | Appalachian Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	646	627.5
Underfunded Benefit Obligation
Projected Benefit Obligation	670.8	647.2	603.1
Accumulated Benefit Obligation	646	627.5
Fair Value of Plan Assets	701.3	637	593.3
Underfunded Status, Projected Benefit Obligation		(10.2)
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2021	1.8
Components of Net Periodic Benefit Cost
Service Cost	10.5	9.4	9.3
Interest Cost	20.3	25.2	23.5
Expected Return on Plan Assets	(33.6)	(37.4)	(36.6)
Amortization of Prior Service Cost (Credit)	0	0	0
Amortization of Net Actuarial Loss	11.2	7	10.6
Net Periodic Benefit Cost (Credit)	8.4	4.2	6.8
Capitalized Portion	(4.5)	(4)	(3.8)
Net Periodic Benefit Cost (Credit) Recognized in Expense	3.9	0.2	3
Pension Plans [Member] | Appalachian Power Co [Member] | Pension Payments [Member]
Estimated Future Benefit Payments and Contributions
2021	44.7
2022	45.1
2023	45.1
2024	45.7
2025	44
Years 2026 to 2030, in Total	209.7
Pension Plans [Member] | Indiana Michigan Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	616.6	586.9
Underfunded Benefit Obligation
Projected Benefit Obligation	653.3	616.1	567
Accumulated Benefit Obligation	616.6	586.9
Fair Value of Plan Assets	698.1	630.5	583.8
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2021	1.3
Components of Net Periodic Benefit Cost
Service Cost	15.4	13.4	13.6
Interest Cost	19.7	23.8	22.1
Expected Return on Plan Assets	(33.3)	(36.8)	(35.7)
Amortization of Prior Service Cost (Credit)	0	0	0
Amortization of Net Actuarial Loss	10.8	6.6	9.8
Net Periodic Benefit Cost (Credit)	12.6	7	9.8
Capitalized Portion	(4.3)	(3.4)	(5.6)
Net Periodic Benefit Cost (Credit) Recognized in Expense	8.3	3.6	4.2
Pension Plans [Member] | Indiana Michigan Power Co [Member] | Pension Payments [Member]
Estimated Future Benefit Payments and Contributions
2021	40.2
2022	42.4
2023	41.5
2024	42.7
2025	42.7
Years 2026 to 2030, in Total	205.2
Pension Plans [Member] | Ohio Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	479.4	464.3
Underfunded Benefit Obligation
Projected Benefit Obligation	510.3	487.8	453.9
Accumulated Benefit Obligation	479.4	464.3
Fair Value of Plan Assets	543.1	499.1	466.1
Components of Net Periodic Benefit Cost
Service Cost	9.7	7.9	7.7
Interest Cost	15.4	19.1	17.7
Expected Return on Plan Assets	(26.3)	(29.3)	(28.8)
Amortization of Prior Service Cost (Credit)	0	0	0
Amortization of Net Actuarial Loss	8.5	5.3	8
Net Periodic Benefit Cost (Credit)	7.3	3	4.6
Capitalized Portion	(5)	(3.7)	(3.6)
Net Periodic Benefit Cost (Credit) Recognized in Expense	2.3	(0.7)	1
Pension Plans [Member] | Ohio Power Co [Member] | Pension Payments [Member]
Estimated Future Benefit Payments and Contributions
2021	35.4
2022	36
2023	34.2
2024	34
2025	33.3
Years 2026 to 2030, in Total	155
Pension Plans [Member] | Public Service Co Of Oklahoma [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	259.9	250.5
Underfunded Benefit Obligation
Projected Benefit Obligation	279.9	267.5	253.8
Accumulated Benefit Obligation	259.9	250.5
Fair Value of Plan Assets	299.8	276.2	261.2
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2021	0.1
Components of Net Periodic Benefit Cost
Service Cost	7.3	6.5	7
Interest Cost	8.5	10.6	9.9
Expected Return on Plan Assets	(14.5)	(16.3)	(16.1)
Amortization of Prior Service Cost (Credit)	0	0	0
Amortization of Net Actuarial Loss	4.7	2.9	4.4
Net Periodic Benefit Cost (Credit)	6	3.7	5.2
Capitalized Portion	(2.8)	(2.4)	(2.6)
Net Periodic Benefit Cost (Credit) Recognized in Expense	3.2	1.3	2.6
Pension Plans [Member] | Public Service Co Of Oklahoma [Member] | Pension Payments [Member]
Estimated Future Benefit Payments and Contributions
2021	21.8
2022	21.2
2023	22.3
2024	21.9
2025	21.1
Years 2026 to 2030, in Total	94.8
Pension Plans [Member] | Southwestern Electric Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	308.5	293.2
Underfunded Benefit Obligation
Projected Benefit Obligation	334.5	314.2	291.4
Accumulated Benefit Obligation	308.5	293.2
Fair Value of Plan Assets	326.9	296.9	281
Underfunded Status, Projected Benefit Obligation	(7.6)	(17.3)
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2021	7.1
Components of Net Periodic Benefit Cost
Service Cost	9.9	8.6	9.3
Interest Cost	10.2	12.4	11.3
Expected Return on Plan Assets	(15.7)	(17.7)	(17.3)
Amortization of Prior Service Cost (Credit)	0	0	0
Amortization of Net Actuarial Loss	5.7	3.4	5.1
Settlements	0	0	0.4
Net Periodic Benefit Cost (Credit)	10.1	6.7	8.8
Capitalized Portion	(3.4)	(2.9)	(3.1)
Net Periodic Benefit Cost (Credit) Recognized in Expense	6.7	3.8	5.7
Pension Plans [Member] | Southwestern Electric Power Co [Member] | Pension Payments [Member]
Estimated Future Benefit Payments and Contributions
2021	25.2
2022	25.4
2023	25.7
2024	25.7
2025	25.3
Years 2026 to 2030, in Total	115.7
Qualified Pension Plans [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	5,171.3	4,929
Underfunded Benefit Obligation
Accumulated Benefit Obligation	5,171.3	4,929
Qualified Pension Plans [Member] | AEP Texas Inc. [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	424.5	417.5
Underfunded Benefit Obligation
Accumulated Benefit Obligation	424.5	417.5
Qualified Pension Plans [Member] | Appalachian Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	645.8	627.3
Underfunded Benefit Obligation
Accumulated Benefit Obligation	645.8	627.3
Qualified Pension Plans [Member] | Indiana Michigan Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	615.8	586.3
Underfunded Benefit Obligation
Accumulated Benefit Obligation	615.8	586.3
Qualified Pension Plans [Member] | Ohio Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	479.2	464.2
Underfunded Benefit Obligation
Accumulated Benefit Obligation	479.2	464.2
Qualified Pension Plans [Member] | Public Service Co Of Oklahoma [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	258.3	248.9
Underfunded Benefit Obligation
Accumulated Benefit Obligation	258.3	248.9
Qualified Pension Plans [Member] | Southwestern Electric Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	307.1	291.9
Underfunded Benefit Obligation
Accumulated Benefit Obligation	307.1	291.9
Nonqualified Pension Plans [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	72.9	69.7
Underfunded Benefit Obligation
Projected Benefit Obligation	81.4
Accumulated Benefit Obligation	72.9	69.7
Fair Value of Plan Assets	0	0
Underfunded Status, Projected Benefit Obligation	(81.4)
Underfunded Status, Accumulated Benefit Obligation	(72.9)	(69.7)
Nonqualified Pension Plans [Member] | AEP Texas Inc. [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	3.6	3.6
Underfunded Benefit Obligation
Projected Benefit Obligation	3.9
Accumulated Benefit Obligation	3.6	3.6
Fair Value of Plan Assets	0	0
Underfunded Status, Projected Benefit Obligation	(3.9)
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
Projected Benefit Obligation	0.5
Accumulated Benefit Obligation	0.2	0.2
Fair Value of Plan Assets	0	0
Underfunded Status, Projected Benefit Obligation	(0.5)
Underfunded Status, Accumulated Benefit Obligation	(0.2)	(0.2)
Nonqualified Pension Plans [Member] | Indiana Michigan Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	0.8	0.6
Underfunded Benefit Obligation
Projected Benefit Obligation	1.7	1.5
Accumulated Benefit Obligation	0.8	0.6
Fair Value of Plan Assets	0	0
Underfunded Status, Projected Benefit Obligation	(1.7)	(1.5)
Underfunded Status, Accumulated Benefit Obligation	(0.8)	(0.6)
Nonqualified Pension Plans [Member] | Ohio Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	0.2	0.1
Underfunded Benefit Obligation
Projected Benefit Obligation	0.6	0.4
Accumulated Benefit Obligation	0.2	0.1
Fair Value of Plan Assets	0	0
Underfunded Status, Projected Benefit Obligation	(0.6)	(0.4)
Underfunded Status, Accumulated Benefit Obligation	(0.2)	(0.1)
Nonqualified Pension Plans [Member] | Public Service Co Of Oklahoma [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	1.6	1.6
Underfunded Benefit Obligation
Projected Benefit Obligation	2	1.9
Accumulated Benefit Obligation	1.6	1.6
Fair Value of Plan Assets	0	0
Underfunded Status, Projected Benefit Obligation	(2)	(1.9)
Underfunded Status, Accumulated Benefit Obligation	(1.6)	(1.6)
Nonqualified Pension Plans [Member] | Southwestern Electric Power Co [Member]
Accumulated Benefit Obligation
Accumulated Benefit Obligation	1.4	1.3
Underfunded Benefit Obligation
Accumulated Benefit Obligation	1.4	1.3
Fair Value of Plan Assets	0	0
Underfunded Status, Accumulated Benefit Obligation	(1.4)	(1.3)
Other Postretirement Benefit Plans [Member]
Underfunded Benefit Obligation
Projected Benefit Obligation	1,210.9	1,225.4	1,194.5
Fair Value of Plan Assets	1,946.7	1,781.8	1,534.2
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2021	3.1
Components of Net Periodic Benefit Cost
Service Cost	10	9.5	11.6
Interest Cost	39.8	50.5	47.4
Expected Return on Plan Assets	(95.6)	(93.7)	(102.2)
Amortization of Prior Service Cost (Credit)	(69.8)	(69.1)	(69.1)
Amortization of Net Actuarial Loss	5.9	22.1	10.5
Settlements	0	0	0
Net Periodic Benefit Cost (Credit)	(109.7)	(80.7)	(101.8)
Capitalized Portion	(4.2)	(3.8)	(4.9)
Net Periodic Benefit Cost (Credit) Recognized in Expense	(113.9)	(84.5)	(106.7)
Other Postretirement Benefit Plans [Member] | Benefit Payments [Member]
Estimated Future Benefit Payments and Contributions
2021	121.6
2022	122.5
2023	117.4
2024	121.9
2025	120.9
Years 2026 to 2030, in Total	573.9
Other Postretirement Benefit Plans [Member] | Medicare Subsidy Receipts [Member]
Estimated Future Benefit Payments and Contributions
2021	0.2
2022	0.2
2023	0.3
2024	0.3
2025	0.3
Years 2026 to 2030, in Total	1.5
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member]
Underfunded Benefit Obligation
Projected Benefit Obligation	96.3	97.8	95.9
Fair Value of Plan Assets	162.3	148.1	129.9
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2021	0.1
Components of Net Periodic Benefit Cost
Service Cost	0.8	0.8	0.9
Interest Cost	3.2	4	3.8
Expected Return on Plan Assets	(8)	(7.8)	(8.6)
Amortization of Prior Service Cost (Credit)	(5.9)	(5.9)	(5.9)
Amortization of Net Actuarial Loss	0.5	1.8	0.8
Net Periodic Benefit Cost (Credit)	(9.4)	(7.1)	(9)
Capitalized Portion	(0.4)	(0.4)	(0.5)
Net Periodic Benefit Cost (Credit) Recognized in Expense	(9.8)	(7.5)	(9.5)
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member] | Benefit Payments [Member]
Estimated Future Benefit Payments and Contributions
2021	9.5
2022	9.9
2023	9.7
2024	10.3
2025	10.4
Years 2026 to 2030, in Total	48.6
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member] | Medicare Subsidy Receipts [Member]
Estimated Future Benefit Payments and Contributions
2021	0
2022	0
2023	0
2024	0
2025	0
Years 2026 to 2030, in Total	0
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member]
Underfunded Benefit Obligation
Projected Benefit Obligation	198.2	203.5	205.5
Fair Value of Plan Assets	293	271	238.4
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2021	1.8
Components of Net Periodic Benefit Cost
Service Cost	1	1	1.1
Interest Cost	6.6	8.7	8.2
Expected Return on Plan Assets	(14.4)	(14.6)	(16)
Amortization of Prior Service Cost (Credit)	(10.2)	(10.1)	(10)
Amortization of Net Actuarial Loss	0.9	3.7	1.9
Net Periodic Benefit Cost (Credit)	(16.1)	(11.3)	(14.8)
Capitalized Portion	(0.4)	(0.4)	(0.5)
Net Periodic Benefit Cost (Credit) Recognized in Expense	(16.5)	(11.7)	(15.3)
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member] | Benefit Payments [Member]
Estimated Future Benefit Payments and Contributions
2021	21.1
2022	20.8
2023	19.8
2024	20.5
2025	20
Years 2026 to 2030, in Total	93.3
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member] | Medicare Subsidy Receipts [Member]
Estimated Future Benefit Payments and Contributions
2021	0.1
2022	0.1
2023	0.1
2024	0.1
2025	0.1
Years 2026 to 2030, in Total	0.6
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member]
Underfunded Benefit Obligation
Projected Benefit Obligation	141.4	142.9	138.3
Fair Value of Plan Assets	238.2	216.3	187.3
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2021	0
Components of Net Periodic Benefit Cost
Service Cost	1.4	1.4	1.6
Interest Cost	4.7	5.8	5.4
Expected Return on Plan Assets	(11.7)	(11.4)	(12.3)
Amortization of Prior Service Cost (Credit)	(9.5)	(9.4)	(9.5)
Amortization of Net Actuarial Loss	0.7	2.7	1.2
Net Periodic Benefit Cost (Credit)	(14.4)	(10.9)	(13.6)
Capitalized Portion	(0.4)	(0.4)	(0.7)
Net Periodic Benefit Cost (Credit) Recognized in Expense	(14.8)	(11.3)	(14.3)
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member] | Benefit Payments [Member]
Estimated Future Benefit Payments and Contributions
2021	15.1
2022	15.3
2023	14.7
2024	15.3
2025	15.1
Years 2026 to 2030, in Total	70.9
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member] | Medicare Subsidy Receipts [Member]
Estimated Future Benefit Payments and Contributions
2021	0
2022	0
2023	0
2024	0
2025	0
Years 2026 to 2030, in Total	0
Other Postretirement Benefit Plans [Member] | Ohio Power Co [Member]
Underfunded Benefit Obligation
Projected Benefit Obligation	126.4	130.2	129.5
Fair Value of Plan Assets	213	197.1	175.4
Components of Net Periodic Benefit Cost
Service Cost	0.9	0.8	0.9
Interest Cost	4.2	5.5	5.1
Expected Return on Plan Assets	(10.5)	(10.8)	(11.7)
Amortization of Prior Service Cost (Credit)	(7)	(6.9)	(6.9)
Amortization of Net Actuarial Loss	0.7	2.5	1.1
Net Periodic Benefit Cost (Credit)	(11.7)	(8.9)	(11.5)
Capitalized Portion	(0.5)	(0.4)	(0.4)
Net Periodic Benefit Cost (Credit) Recognized in Expense	(12.2)	(9.3)	(11.9)
Other Postretirement Benefit Plans [Member] | Ohio Power Co [Member] | Benefit Payments [Member]
Estimated Future Benefit Payments and Contributions
2021	13.7
2022	13.9
2023	13.2
2024	13.7
2025	13.4
Years 2026 to 2030, in Total	61.7
Other Postretirement Benefit Plans [Member] | Ohio Power Co [Member] | Medicare Subsidy Receipts [Member]
Estimated Future Benefit Payments and Contributions
2021	0
2022	0
2023	0
2024	0
2025	0
Years 2026 to 2030, in Total	0
Other Postretirement Benefit Plans [Member] | Public Service Co Of Oklahoma [Member]
Underfunded Benefit Obligation
Projected Benefit Obligation	64	64.7	62.3
Fair Value of Plan Assets	107.8	98	84.3
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2021	0
Components of Net Periodic Benefit Cost
Service Cost	0.7	0.6	0.7
Interest Cost	2.1	2.6	2.5
Expected Return on Plan Assets	(5.2)	(5.1)	(5.6)
Amortization of Prior Service Cost (Credit)	(4.4)	(4.3)	(4.3)
Amortization of Net Actuarial Loss	0.3	1.2	0.5
Net Periodic Benefit Cost (Credit)	(6.5)	(5)	(6.2)
Capitalized Portion	(0.3)	(0.2)	(0.3)
Net Periodic Benefit Cost (Credit) Recognized in Expense	(6.8)	(5.2)	(6.5)
Other Postretirement Benefit Plans [Member] | Public Service Co Of Oklahoma [Member] | Benefit Payments [Member]
Estimated Future Benefit Payments and Contributions
2021	6.4
2022	6.7
2023	6.6
2024	6.9
2025	6.9
Years 2026 to 2030, in Total	32.1
Other Postretirement Benefit Plans [Member] | Public Service Co Of Oklahoma [Member] | Medicare Subsidy Receipts [Member]
Estimated Future Benefit Payments and Contributions
2021	0
2022	0
2023	0
2024	0
2025	0
Years 2026 to 2030, in Total	0
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member]
Underfunded Benefit Obligation
Projected Benefit Obligation	77.1	77.4	72.7
Fair Value of Plan Assets	129.9	117.2	98.5
Estimated Future Benefit Payments and Contributions
Expected Contributions and Payments During 2021	0
Components of Net Periodic Benefit Cost
Service Cost	0.8	0.8	0.9
Interest Cost	2.5	3.1	2.8
Expected Return on Plan Assets	(6.3)	(5.9)	(6.4)
Amortization of Prior Service Cost (Credit)	(5.2)	(5.2)	(5.2)
Amortization of Net Actuarial Loss	0.4	1.4	0.6
Settlements	0	0	0
Net Periodic Benefit Cost (Credit)	(7.8)	(5.8)	(7.3)
Capitalized Portion	(0.3)	(0.3)	(0.3)
Net Periodic Benefit Cost (Credit) Recognized in Expense	(8.1)	$ (6.1)	$ (7.6)
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member] | Benefit Payments [Member]
Estimated Future Benefit Payments and Contributions
2021	7.5
2022	7.8
2023	7.6
2024	8.2
2025	8.2
Years 2026 to 2030, in Total	39.1
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member] | Medicare Subsidy Receipts [Member]
Estimated Future Benefit Payments and Contributions
2021	0
2022	0
2023	0
2024	0
2025	0
Years 2026 to 2030, in Total	$ 0

Business Segments (Details)

Business Segments (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Reportable Segment Information
Revenue from Contracts with Customers		$ 14,918.5		$ 15,561.4		$ 16,195.7
Sales to AEP Affiliates		0		0		0
Total Revenues		14,918.5		15,561.4		16,195.7
Asset Impairments and Other Related Charges		0		156.4		70.6
Utilities Operating Expense, Depreciation and Amortization		2,682.8		2,514.5		2,286.6
Allowance for Equity Funds Used During Construction		148.1		168.4		132.5
Interest Expense		1,165.7		1,072.5		984.4
Income Tax Expense (Benefit)		40.5		(12.9)		115.3
Equity Earnings (Loss) of Unconsolidated Subsidiaries		91.1		72.1		73.1
Net Income (Loss)		2,196.7		1,919.8		1,931.3
Gross Property Additions		6,246.3		6,969.8		6,325.5
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)		84,313		79,145.7
Accumulated Depreciation and Amortization		20,411.4		19,007.6
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		63,901.6		60,138.1
Total Assets		80,757.2		75,892.3		68,802.8
Investments in Equity Method Investees		1,406.3		1,356.6
Affiliated Long Term Debt Current				0
Long-term Debt Due Within One Year		2,086.1		1,598.7
Long-term Debt - Affiliated		0		0
Long-term Debt		28,986.4		25,126.8
Total Long-term Debt Outstanding		31,072.5		26,725.5
AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contracts with Customers		1,232.7		1,042.1		832
Sales to AEP Affiliates		896.3		806.7		598.9
Total Revenues		1,145.7		1,021.4		776.1
Utilities Operating Expense, Depreciation and Amortization		249		176		133.9
Interest Income		2.4		3		2.5
Allowance for Equity Funds Used During Construction		74		84.3		70.6
Interest Expense		127.8		97.4		83.2
Income Tax Expense (Benefit)		106.7		117.4		84.1
Net Income (Loss)		423.4		439.7		315.9
Gross Property Additions		1,621.9		1,419.5		1,570.8
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)		11,345.6		9,893.2
Accumulated Depreciation and Amortization		572.8		402.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		10,772.8		9,490.9
Notes Receivable, Related Parties		0		0
Total Assets		11,246		9,890.8		8,394.1
Long-term Debt Due Within One Year		50		0
Long-term Debt		3,898.5		3,427.3
Total Long-term Debt Outstanding		3,948.5		3,427.3
Vertically Integrated Utilities [Member]
Reportable Segment Information
Revenue from Contracts with Customers		8,753.2		9,245.7		9,556.7
Transmission and Distribution Utilities Revenues [Member]
Reportable Segment Information
Revenue from Contracts with Customers		4,238.7		4,319		4,552.3
Transmission [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contracts with Customers		248.8		214.6		177
Generation and Marketing Revenues [Member]
Reportable Segment Information
Revenue from Contracts with Customers		1,621		1,721.8		1,818.1
Other Revenues [Member]
Reportable Segment Information
Revenue from Contracts with Customers		305.6		274.9		268.6
Total Revenues		61.5	[1]	61.7	[2]	25	[3]
Other Revenues [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contracts with Customers		0.6		0.1		0.2
Total Revenues		0	[4]	0	[5]	0	[6]
Reconciling Adjustments [Member]
Reportable Segment Information
Revenue from Contracts with Customers		0		0		0
Sales to AEP Affiliates		(1,328)		(1,314.8)		(942.4)
Total Revenues		(1,328)		(1,314.8)		(942.4)
Asset Impairments and Other Related Charges				0		0
Utilities Operating Expense, Depreciation and Amortization		0		24.5	[7]	57.1	[7]
Interest Expense		(42.1)		(66.1)	[7]	(59.7)	[7]
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		(15.3)		(20.4)		(39.2)
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)		0		(354.5)	[7]
Accumulated Depreciation and Amortization		0		(186.4)	[7]
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		0		(168.1)	[7]
Total Assets	[8]	(3,961.7)		(3,801.3)	[7]	(2,714.8)	[7]
Investments in Equity Method Investees		0		0
Affiliated Long Term Debt Current				(20)
Long-term Debt Due Within One Year		0		0
Long-term Debt - Affiliated		(65)		(39)
Long-term Debt		0		0
Total Long-term Debt Outstanding		(65)		(59)
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	[9]	(148.1)		(122.1)		(103.4)
Allowance for Equity Funds Used During Construction		0		0		0
Interest Expense	[9]	(148.1)		(122.1)		(103.4)
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
Accumulated Depreciation and Amortization		0		0
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		0		0
Notes Receivable, Related Parties	[10]	(3,948.5)		(3,427.3)
Total Assets	[11]	(4,023.1)		(3,493.3)		(2,869.8)
Total Long-term Debt Outstanding	[10]	(3,990)		(3,465)
Reconciling Adjustments [Member] | Other Revenues [Member]
Reportable Segment Information
Total Revenues		(74.9)	[1]	(139.3)	[2]	(98)	[3],[12]
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		126.2		121.4		88.8
Total Revenues		8,879.4		9,367.1		9,645.5
Asset Impairments and Other Related Charges				92.9		3.4
Utilities Operating Expense, Depreciation and Amortization		1,600.5		1,447		1,316.2
Interest Expense		565		568.3		567.8
Income Tax Expense (Benefit)		(7)		(97.7)		5.7
Equity Earnings (Loss) of Unconsolidated Subsidiaries		2.9		3		2.7
Net Income (Loss)		1,064.5		985.6		995.5
Gross Property Additions		2,291.2		2,437.4		2,282.2
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)		49,023.3		47,323.7
Accumulated Depreciation and Amortization		15,586.2		14,580.4
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		33,437.1		32,743.3
Total Assets		42,752.7		41,228.8		38,874.3
Investments in Equity Method Investees		37.1		41.7
Affiliated Long Term Debt Current				20
Long-term Debt Due Within One Year		1,034.6		704.7
Long-term Debt - Affiliated		65		39
Long-term Debt		12,375.6		12,162
Total Long-term Debt Outstanding		13,475.2		12,925.7
Vertically Integrated Utilities [Member] | Vertically Integrated Utilities [Member]
Reportable Segment Information
Revenue from Contracts with Customers		8,753.2		9,245.7		9,556.7
Vertically Integrated Utilities [Member] | Other Revenues [Member]
Reportable Segment Information
Total Revenues		0	[1]	0	[2]	(10.5)	[3]
Transmission and Distribution Companies [Member]
Reportable Segment Information
Sales to AEP Affiliates		107.2		163.5		100.8
Total Revenues		4,345.9		4,482.5		4,653.1
Asset Impairments and Other Related Charges				32.5		0
Utilities Operating Expense, Depreciation and Amortization		751.1		789.5		734.1
Interest Expense		289.2		243.3		248.1
Income Tax Expense (Benefit)		29.7		(25.2)		42.4
Equity Earnings (Loss) of Unconsolidated Subsidiaries		0		0		0
Net Income (Loss)		496.4		451		527.4
Gross Property Additions		2,108.1		2,074.3		2,162.4
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)		21,145		19,773.3
Accumulated Depreciation and Amortization		3,879.3		3,911.2
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		17,265.7		15,862.1
Total Assets		19,765.9		18,757.5		17,083.4
Investments in Equity Method Investees		2.1		2.5
Affiliated Long Term Debt Current				0
Long-term Debt Due Within One Year		588.8		392.2
Long-term Debt - Affiliated		0		0
Long-term Debt		6,661.9		6,248.1
Total Long-term Debt Outstanding		7,250.7		6,640.3
Transmission and Distribution Companies [Member] | Transmission and Distribution Utilities Revenues [Member]
Reportable Segment Information
Revenue from Contracts with Customers		4,238.7		4,319		4,552.3
Transmission and Distribution Companies [Member] | Other Revenues [Member]
Reportable Segment Information
Total Revenues		83	[1]	150	[2]	102.3	[3]
AEP Transmission Holdco
Reportable Segment Information
Sales to AEP Affiliates		901.4		813		555.5
Total Revenues		1,198.8		1,073.2		804.1
Asset Impairments and Other Related Charges				0		0
Utilities Operating Expense, Depreciation and Amortization		257.6		183.4		137.8
Interest Expense		133.2		103.3		90.7
Income Tax Expense (Benefit)		130.8		136.2		95.3
Equity Earnings (Loss) of Unconsolidated Subsidiaries		82.4		72.8		68.7
Net Income (Loss)		508.5		520.1		373
Gross Property Additions		1,649.3		1,458.9		1,614.1
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)		11,827.2		10,334
Accumulated Depreciation and Amortization		595.7		418.9
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		11,231.5		9,915.1
Total Assets		12,627.3		11,143.5		9,543.7
Investments in Equity Method Investees		831.3		787.5
Affiliated Long Term Debt Current				0
Long-term Debt Due Within One Year		52.3		0
Long-term Debt - Affiliated		0		0
Long-term Debt		4,075.7		3,593.8
Total Long-term Debt Outstanding		4,128		3,593.8
AEP Transmission Holdco | Transmission [Member]
Reportable Segment Information
Revenue from Contracts with Customers		297.4		260.2		248.6
Generation and Marketing [Member]
Reportable Segment Information
Sales to AEP Affiliates		104.6		135.8		122.2
Total Revenues		1,725.6		1,857.6		1,940.3
Asset Impairments and Other Related Charges				31		47.7
Utilities Operating Expense, Depreciation and Amortization		72.8		69.5		41
Interest Expense		24		30		14.9
Income Tax Expense (Benefit)		(108)		(53.8)		(49.2)
Equity Earnings (Loss) of Unconsolidated Subsidiaries		3.2		(3.8)		0.5
Net Income (Loss)		216.9		104.1		134.7
Gross Property Additions		197		1,005.1		289.7
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)		1,910.2		1,650.8
Accumulated Depreciation and Amortization		166.1		99
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		1,744.1		1,551.8
Total Assets		3,585.9		3,123.8		1,979.7
Investments in Equity Method Investees		467		459.5
Affiliated Long Term Debt Current				0
Long-term Debt Due Within One Year		0		0
Long-term Debt - Affiliated		0		0
Long-term Debt		0		0
Total Long-term Debt Outstanding		0		0
Generation and Marketing [Member] | Generation and Marketing Revenues [Member]
Reportable Segment Information
Revenue from Contracts with Customers		1,621		1,721.8		1,818.1
Generation and Marketing [Member] | Other Revenues [Member]
Reportable Segment Information
Total Revenues		43.6	[1]	59.9	[2]	22.3	[3]
All Other [Member]
Reportable Segment Information
Sales to AEP Affiliates	[13]	88.6		81.1		75.1
Total Revenues	[13]	96.8		95.8		95.1
Asset Impairments and Other Related Charges	[13]			0		19.5
Utilities Operating Expense, Depreciation and Amortization	[13]	0.8		0.6		0.4
Interest Expense	[13]	196.4		193.7		122.6
Income Tax Expense (Benefit)	[13]	(5)		27.6		21.1
Equity Earnings (Loss) of Unconsolidated Subsidiaries	[13]	2.6		0.1		1.2
Net Income (Loss)	[13]	(89.6)		(141)		(99.3)
Gross Property Additions	[13]	16		14.5		16.3
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)	[13]	407.3		418.4
Accumulated Depreciation and Amortization	[13]	184.1		184.5
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	[13]	223.2		233.9
Total Assets	[13],[14]	5,987.1		5,440		4,036.5
Investments in Equity Method Investees	[13]	68.8		65.4
Affiliated Long Term Debt Current	[13]			0
Long-term Debt Due Within One Year	[13],[15]	410.4		501.8
Long-term Debt - Affiliated	[13]	0		0
Long-term Debt	[13]	5,873.2	[15]	3,122.9
Total Long-term Debt Outstanding	[13]	6,283.6		3,624.7	[15]
All Other [Member] | Other Revenues [Member]
Reportable Segment Information
Revenue from Contracts with Customers	[13]	8.2		14.7		20
Total Revenues		9.8	[1]	(8.9)	[2]	8.9	[3]
State Transcos [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Sales to AEP Affiliates		896.3		806.7		598.9
Total Revenues		1,145.7		1,021.4		776.1
Utilities Operating Expense, Depreciation and Amortization		249		176		133.9
Interest Income		0.9		1.3		1.3
Allowance for Equity Funds Used During Construction		74		84.3		70.6
Interest Expense		127.8		97.4		83.2
Income Tax Expense (Benefit)		106.5		117.1		83.9
Net Income (Loss)		422.3		438.6		314.9
Gross Property Additions		1,621.9		1,419.5		1,570.8
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)		11,345.6		9,893.2
Accumulated Depreciation and Amortization		572.8		402.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		10,772.8		9,490.9
Notes Receivable, Related Parties		0		0
Total Assets		11,185.1		9,865		8,406.8
Total Long-term Debt Outstanding		3,990		3,465
State Transcos [Member] | Transmission [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contracts with Customers		248.8		214.6		177
State Transcos [Member] | Other Revenues [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contracts with Customers		0.6		0.1		0.2
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		149.6		123.8		104.6
Allowance for Equity Funds Used During Construction		0		0		0
Interest Expense		148.1		122.1		103.4
Income Tax Expense (Benefit)		0.2		0.3		0.2
Net Income (Loss)	[16]	1.1		1.1		1
Gross Property Additions		0		0		0
Balance Sheet Information
Property, Plant and Equipment, Gross, Period Increase (Decrease)		0		0
Accumulated Depreciation and Amortization		0		0
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		0		0
Notes Receivable, Related Parties		3,948.5		3,427.3
Total Assets	[17]	4,084		3,519.1		2,857.1
Total Long-term Debt Outstanding		3,948.5		3,427.3
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
[1]	Amounts include affiliated and nonaffiliated revenues.
[2]	Amounts include affiliated and nonaffiliated revenues.
[3]	Amounts include affiliated and nonaffiliated revenues.
[4]	Amounts include affiliated and nonaffiliated revenues.
[5]	Amounts include affiliated and nonaffiliated revenues.
[6]	Amounts include affiliated and nonaffiliated revenues.
[7]	Includes eliminations due to an intercompany finance lease.
[8]	Reconciling Adjustments for Total Assets primarily include elimination of intercompany advances to affiliates and intercompany accounts receivable.
[9]	Elimination of intercompany interest income/interest expense on affiliated debt arrangement.
[10]	Elimination of intercompany debt.
[11]	Primarily relates to elimination of Notes Receivable from the State Transcos.
[12]	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.
[13]	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.
[14]	Includes elimination of AEP Parent’s investments in wholly-owned subsidiary companies.
[15]	Amounts reflect the impact of fair value hedge accounting. See “Accounting for Fair Value Hedging Strategies” section of Note 10 for additional information.
[16]	Includes elimination of AEPTCo Parent’s equity earnings in the State Transcos.
[17]	Includes elimination of AEPTCo Parent’s investments in the State Transcos.

Derivatives and Hedging (Detail

Derivatives and Hedging (Details) gal in Millions, MWh in Millions, MMBTU in Millions		12 Months Ended
		Dec. 31, 2020USD ($)MMBTUMWhgal		Dec. 31, 2019USD ($)MMBTUMWhgal		Dec. 31, 2018USD ($)
Change in Fair Value Recognized in AOCI		$ (66,400,000)		$ (69,700,000)		$ 6,600,000
Cash Collateral Netting
Cash Collateral Received Netted Against Risk Management Assets		3,000,000		5,000,000
Cash Collateral Paid Netted Against Risk Management Liabilities		7,000,000		39,000,000
Fair Value of Derivative Instruments
Current Risk Management Assets		94,700,000		172,800,000
Long-term Risk Management Assets		242,200,000		266,600,000
Total Assets		336,900,000		439,400,000
Current Risk Management Liabilities		78,800,000		114,300,000
Long-term Risk Management Liabilities		232,800,000		261,800,000
Total Liabilities		311,600,000		376,100,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		116,900,000		125,000,000		291,300,000
Impact of Fair Value Hedges on the Balance Sheet
Carrying Amount of Hedged Asset (Liability)	[1],[2]	(995,900,000)		(510,800,000)
Cumulative Fair Value Hedging Adjustment in the Carrying Amount of the Hedged Asset (Liability)	[1],[2]	(51,700,000)		(14,500,000)
Impact of Cash Flow Hedges on the Balance Sheet
Gain (Loss) on Fair Value Hedging Instruments	[3]	41,100,000		31,900,000		(11,300,000)
Gain (Loss) on Fair Value Portion of Long Term Debt	[3]	(41,100,000)		(31,900,000)		11,300,000
Collateral Triggering Events
Liabilities for Contracts with Cross Default Provisions Prior to Contractural Netting Arrangements		188,400,000		267,300,000
Amount of Cash Collateral Posted		0		3,700,000
Additional Settlement Liability if Cross Default Provision is Triggered		169,200,000		246,700,000
Derivatives and Hedging (Textuals)
Hedged Liability, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)		(53,000,000)		0
Notional Amount of a Discontinued Hedge		500,000,000
Deferred (Gain) Loss on Discontinuation of Fair Value Hedge		57,000,000
AEP Texas Inc. [Member]
Change in Fair Value Recognized in AOCI		2,700,000		1,100,000		(1,000,000)
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		(1,000,000)		300,000		(400,000)
Appalachian Power Co [Member]
Change in Fair Value Recognized in AOCI		7,000,000		13,400,000		(3,300,000)
Fair Value of Derivative Instruments
Current Risk Management Assets		22,400,000		39,400,000
Total Assets		22,500,000
Current Risk Management Liabilities		4,600,000		1,900,000
Total Liabilities		4,700,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		21,300,000		4,100,000		141,100,000
Collateral Triggering Events
Liabilities for Contracts with Cross Default Provisions Prior to Contractural Netting Arrangements		4,300,000		2,300,000
Amount of Cash Collateral Posted		0		0
Additional Settlement Liability if Cross Default Provision is Triggered		3,500,000		400,000
Indiana Michigan Power Co [Member]
Change in Fair Value Recognized in AOCI		3,100,000		800,000		(600,000)
Fair Value of Derivative Instruments
Current Risk Management Assets		3,600,000		9,800,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		12,000,000		25,200,000		11,700,000
Collateral Triggering Events
Liabilities for Contracts with Cross Default Provisions Prior to Contractural Netting Arrangements		500,000		1,300,000
Amount of Cash Collateral Posted		0		0
Additional Settlement Liability if Cross Default Provision is Triggered		100,000		200,000
Ohio Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Liabilities		8,700,000		7,300,000
Long-term Risk Management Liabilities		101,600,000		96,300,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		5,000,000		6,000,000		25,600,000
Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		10,300,000		15,800,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		38,600,000		35,600,000		36,600,000
Southwestern Electric Power Co [Member]
Change in Fair Value Recognized in AOCI		3,200,000		3,700,000		(800,000)
Fair Value of Derivative Instruments
Current Risk Management Assets		3,200,000		6,400,000
Current Risk Management Liabilities		700,000		1,900,000
Long-term Risk Management Liabilities		1,000,000		3,100,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		21,000,000		25,000,000		11,200,000
Collateral Triggering Events
Liabilities for Contracts with Cross Default Provisions Prior to Contractural Netting Arrangements		1,800,000		5,100,000
Amount of Cash Collateral Posted		0		0
Additional Settlement Liability if Cross Default Provision is Triggered		1,800,000		5,100,000
Risk Management Contracts [Member]
Fair Value of Derivative Instruments
Total Assets	[4]	322,100,000	[5]	408,800,000	[6]
Total Liabilities	[4]	218,900,000	[5]	239,000,000	[6]
Risk Management Contracts [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Total Assets	[4]	0
Risk Management Contracts [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[4],[7]	20,100,000		39,500,000
Total Liabilities	[4],[7]	1,300,000		1,900,000
Risk Management Contracts [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[4],[7]	3,700,000		9,900,000
Total Liabilities	[4],[7]	200,000		500,000
Risk Management Contracts [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[4],[7]	0
Total Liabilities	[4],[7]	110,300,000		103,600,000
Risk Management Contracts [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Total Assets	[4],[7]	10,300,000		15,800,000
Total Liabilities	[4],[7]			0
Risk Management Contracts [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[4],[7]	3,200,000		6,400,000
Total Liabilities	[4],[7]	1,700,000		5,000,000
Commodity [Member]
Impact of Cash Flow Hedges on the Balance Sheet
AOCI Gain (Loss) Net of Tax		(60,600,000)		(103,500,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months		$ (27,100,000)		(51,700,000)
Derivatives and Hedging (Textuals)
Maximum Length of Time Hedged in Price Risk Cash Flow Hedge		123 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	[8]	239,100,000		513,900,000
Long-term Risk Management Assets	[8]	275,900,000		290,800,000
Total Assets	[8]	515,000,000		804,700,000
Current Risk Management Liabilities	[8]	193,000,000		424,500,000
Long-term Risk Management Liabilities	[8]	222,200,000		244,500,000
Total Liabilities	[8]	415,200,000		669,000,000
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	99,800,000		135,700,000
Commodity [Member] | Risk Management Contracts [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[8]	400,000		0
Long-term Risk Management Assets	[8]	0		0
Total Assets	[8]	400,000		0
Current Risk Management Liabilities	[8]	0		0
Long-term Risk Management Liabilities	[8]	0		0
Total Liabilities	[8]	0		0
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	400,000		0
Commodity [Member] | Risk Management Contracts [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[8]	38,800,000		124,400,000
Long-term Risk Management Assets	[8]	700,000		900,000
Total Assets	[8]	39,500,000		125,300,000
Current Risk Management Liabilities	[8]	19,700,000		86,200,000
Long-term Risk Management Liabilities	[8]	600,000		700,000
Total Liabilities	[8]	20,300,000		86,900,000
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	19,200,000		38,400,000
Commodity [Member] | Risk Management Contracts [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[8]	17,200,000		66,900,000
Long-term Risk Management Assets	[8]	500,000		500,000
Total Assets	[8]	17,700,000		67,400,000
Current Risk Management Liabilities	[8]	12,100,000		55,200,000
Long-term Risk Management Liabilities	[8]	400,000		400,000
Total Liabilities	[8]	12,500,000		55,600,000
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	5,200,000		11,800,000
Commodity [Member] | Risk Management Contracts [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[8]	300,000		0
Long-term Risk Management Assets	[8]	0		0
Total Assets	[8]	300,000		0
Current Risk Management Liabilities	[8]	8,700,000		7,300,000
Long-term Risk Management Liabilities	[8]	101,600,000		96,300,000
Total Liabilities	[8]	110,300,000		103,600,000
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	(110,000,000)		(103,600,000)
Commodity [Member] | Risk Management Contracts [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[8]	10,500,000		16,300,000
Long-term Risk Management Assets	[8]	0		0
Total Assets	[8]	10,500,000		16,300,000
Current Risk Management Liabilities	[8]	0		500,000
Long-term Risk Management Liabilities	[8]	0		0
Total Liabilities	[8]	0		500,000
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	10,500,000		15,800,000
Commodity [Member] | Risk Management Contracts [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[8]	3,400,000		6,500,000
Long-term Risk Management Assets	[8]	0		0
Total Assets	[8]	3,400,000		6,500,000
Current Risk Management Liabilities	[8]	700,000		2,000,000
Long-term Risk Management Liabilities	[8]	1,000,000		3,100,000
Total Liabilities	[8]	1,700,000		5,100,000
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	1,700,000		1,400,000
Commodity [Member] | Hedging Contracts [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[8]	21,100,000		11,500,000
Long-term Risk Management Assets	[8]	18,000,000		11,000,000
Total Assets	[8]	39,100,000		22,500,000
Current Risk Management Liabilities	[8]	54,400,000		72,300,000
Long-term Risk Management Liabilities	[8]	60,100,000		75,700,000
Total Liabilities	[8]	114,500,000		148,000,000
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	(75,400,000)		(125,500,000)
Interest Rate [Member]
Commodity
Derivative, Notional Amount		1,150,000,000		625,000,000
Impact of Cash Flow Hedges on the Balance Sheet
AOCI Gain (Loss) Net of Tax		(47,500,000)		(11,500,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months		$ (5,700,000)		(2,100,000)
Derivatives and Hedging (Textuals)
Maximum Length of Time Hedged in Price Risk Cash Flow Hedge		120 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		(2,300,000)		(3,400,000)
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		200,000,000		0
Impact of Cash Flow Hedges on the Balance Sheet
AOCI Gain (Loss) Net of Tax		(800,000)		900,000
Portion Expected to be Reclassified to Net Income During the Next Twelve Months		400,000		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		(8,300,000)		(9,900,000)
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
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		100,000		1,100,000
Portion Expected to be Reclassified to Net Income During the Next Twelve Months		100,000		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		(300,000)		(1,800,000)
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	[8]	5,000,000		6,500,000
Long-term Risk Management Assets	[8]	0		12,600,000
Total Assets	[8]	5,000,000		19,100,000
Current Risk Management Liabilities	[8]	3,400,000		0
Long-term Risk Management Liabilities	[8]	4,100,000		0
Total Liabilities	[8]	7,500,000		0
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	(2,500,000)		19,100,000
Interest Rate [Member] | Hedging Contracts [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[8]	2,400,000
Long-term Risk Management Assets	[8]	0
Total Assets	[8]	2,400,000
Current Risk Management Liabilities	[8]	3,400,000
Long-term Risk Management Liabilities	[8]	0
Total Liabilities	[8]	3,400,000
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	(1,000,000)
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		265,200,000		531,900,000
Long-term Risk Management Assets		293,900,000		314,400,000
Total Assets		559,100,000		846,300,000
Current Risk Management Liabilities		250,800,000		496,800,000
Long-term Risk Management Liabilities		286,400,000		320,200,000
Total Liabilities		537,200,000		817,000,000
Total MTM Derivative Contract Net Assets (Liabilities)		21,900,000		29,300,000
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		41,200,000
Long-term Risk Management Assets		700,000
Total Assets		41,900,000
Current Risk Management Liabilities		23,100,000
Long-term Risk Management Liabilities		600,000
Total Liabilities		23,700,000
Total MTM Derivative Contract Net Assets (Liabilities)		18,200,000
Gross Amounts Offset in the Statement of Financial Position [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[9]	(170,500,000)		(359,100,000)
Long-term Risk Management Assets	[9]	(51,700,000)		(47,800,000)
Total Assets	[9]	(222,200,000)		(406,900,000)
Current Risk Management Liabilities	[9]	(172,000,000)		(382,500,000)
Long-term Risk Management Liabilities	[9]	(53,600,000)		(58,400,000)
Total Liabilities	[9]	(225,600,000)		(440,900,000)
Total MTM Derivative Contract Net Assets (Liabilities)	[9]	3,400,000		34,000,000
Gross Amounts Offset in the Statement of Financial Position [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[9]	(400,000)		0
Long-term Risk Management Assets	[9]	0		0
Total Assets	[9]	(400,000)		0
Current Risk Management Liabilities	[9]	0		0
Long-term Risk Management Liabilities	[9]	0		0
Total Liabilities	[9]	0		0
Total MTM Derivative Contract Net Assets (Liabilities)	[9]	(400,000)		0
Gross Amounts Offset in the Statement of Financial Position [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[9]	(18,800,000)		(85,000,000)
Long-term Risk Management Assets	[9]	(600,000)		(800,000)
Total Assets	[9]	(19,400,000)		(85,800,000)
Current Risk Management Liabilities	[9]	(18,500,000)		(84,300,000)
Long-term Risk Management Liabilities	[9]	(500,000)		(700,000)
Total Liabilities	[9]	(19,000,000)		(85,000,000)
Total MTM Derivative Contract Net Assets (Liabilities)	[9]	(400,000)		(800,000)
Gross Amounts Offset in the Statement of Financial Position [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[9]	(13,600,000)		(57,100,000)
Long-term Risk Management Assets	[9]	(400,000)		(400,000)
Total Assets	[9]	(14,000,000)		(57,500,000)
Current Risk Management Liabilities	[9]	(12,000,000)		(54,700,000)
Long-term Risk Management Liabilities	[9]	(300,000)		(400,000)
Total Liabilities	[9]	(12,300,000)		(55,100,000)
Total MTM Derivative Contract Net Assets (Liabilities)	[9]	(1,700,000)		(2,400,000)
Gross Amounts Offset in the Statement of Financial Position [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[9]	(300,000)		0
Long-term Risk Management Assets	[9]	0		0
Total Assets	[9]	(300,000)		0
Current Risk Management Liabilities	[9]	0		0
Long-term Risk Management Liabilities	[9]	0		0
Total Liabilities	[9]	0		0
Total MTM Derivative Contract Net Assets (Liabilities)	[9]	(300,000)		0
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	[9]	(200,000)		(500,000)
Long-term Risk Management Assets	[9]	0		0
Total Assets	[9]	(200,000)		(500,000)
Current Risk Management Liabilities	[9]	0		(500,000)
Long-term Risk Management Liabilities	[9]	0		0
Total Liabilities	[9]	0		(500,000)
Total MTM Derivative Contract Net Assets (Liabilities)	[9]	(200,000)		0
Gross Amounts Offset in the Statement of Financial Position [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[9]	(200,000)		(100,000)
Long-term Risk Management Assets	[9]	0		0
Total Assets	[9]	(200,000)		(100,000)
Current Risk Management Liabilities	[9]	0		(100,000)
Long-term Risk Management Liabilities	[9]	0		0
Total Liabilities	[9]	0		(100,000)
Total MTM Derivative Contract Net Assets (Liabilities)	[9]	(200,000)		0
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[10]	94,700,000		172,800,000
Long-term Risk Management Assets	[10]	242,200,000		266,600,000
Total Assets	[10]	336,900,000		439,400,000
Current Risk Management Liabilities	[10]	78,800,000		114,300,000
Long-term Risk Management Liabilities	[10]	232,800,000		261,800,000
Total Liabilities	[10]	311,600,000		376,100,000
Total MTM Derivative Contract Net Assets (Liabilities)	[10]	25,300,000		63,300,000
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	[10]	0		0
Long-term Risk Management Assets	[10]	0		0
Total Assets	[10]	0		0
Current Risk Management Liabilities	[10]	0		0
Long-term Risk Management Liabilities	[10]	0		0
Total Liabilities	[10]	0		0
Total MTM Derivative Contract Net Assets (Liabilities)	[10]	0		0
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	[10]	22,400,000		39,400,000
Long-term Risk Management Assets	[10]	100,000		100,000
Total Assets	[10]	22,500,000		39,500,000
Current Risk Management Liabilities	[10]	4,600,000		1,900,000
Long-term Risk Management Liabilities	[10]	100,000		0
Total Liabilities	[10]	4,700,000		1,900,000
Total MTM Derivative Contract Net Assets (Liabilities)	[10]	17,800,000		37,600,000
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	[10]	3,600,000		9,800,000
Long-term Risk Management Assets	[10]	100,000		100,000
Total Assets	[10]	3,700,000		9,900,000
Current Risk Management Liabilities	[10]	100,000		500,000
Long-term Risk Management Liabilities	[10]	100,000		0
Total Liabilities	[10]	200,000		500,000
Total MTM Derivative Contract Net Assets (Liabilities)	[10]	3,500,000		9,400,000
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	[10]	0		0
Long-term Risk Management Assets	[10]	0		0
Total Assets	[10]	0		0
Current Risk Management Liabilities	[10]	8,700,000		7,300,000
Long-term Risk Management Liabilities	[10]	101,600,000		96,300,000
Total Liabilities	[10]	110,300,000		103,600,000
Total MTM Derivative Contract Net Assets (Liabilities)	[10]	(110,300,000)		(103,600,000)
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	[10]	10,300,000		15,800,000
Long-term Risk Management Assets	[10]	0		0
Total Assets	[10]	10,300,000		15,800,000
Current Risk Management Liabilities	[10]	0		0
Long-term Risk Management Liabilities	[10]	0		0
Total Liabilities	[10]	0		0
Total MTM Derivative Contract Net Assets (Liabilities)	[10]	10,300,000		15,800,000
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	[10]	3,200,000		6,400,000
Long-term Risk Management Assets	[10]	0		0
Total Assets	[10]	3,200,000		6,400,000
Current Risk Management Liabilities	[10]	700,000		1,900,000
Long-term Risk Management Liabilities	[10]	1,000,000		3,100,000
Total Liabilities	[10]	1,700,000		5,000,000
Total MTM Derivative Contract Net Assets (Liabilities)	[10]	$ 1,500,000		$ 1,400,000
Power [Member]
Commodity
Derivative, Energy Notional Amount | MWh		331.3		365.9
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		46.9		61
Power [Member] | Indiana Michigan Power Co [Member]
Commodity
Derivative, Energy Notional Amount | MWh		19.7		26.8
Power [Member] | Ohio Power Co [Member]
Commodity
Derivative, Energy Notional Amount | MWh		3		7.1
Power [Member] | Public Service Co Of Oklahoma [Member]
Commodity
Derivative, Energy Notional Amount | MWh		11.9		14.9
Power [Member] | Southwestern Electric Power Co [Member]
Commodity
Derivative, Energy Notional Amount | MWh		4		4.4
Natural Gas [Member]
Commodity
Derivative, Energy Notional Amount | MMBTU		26.9		40.7
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		0
Natural Gas [Member] | Indiana Michigan Power Co [Member]
Commodity
Derivative, Energy Notional Amount | MMBTU		0		0
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		7.9		11.6
Heating Oil and Gasoline [Member]
Commodity
Derivative, Volume Notional Amount | gal		6.9		6.9
Heating Oil and Gasoline [Member] | AEP Texas Inc. [Member]
Commodity
Derivative, Volume Notional Amount | gal		1.8		1.8
Heating Oil and Gasoline [Member] | Appalachian Power Co [Member]
Commodity
Derivative, Volume Notional Amount | gal		1.1		1.1
Heating Oil and Gasoline [Member] | Indiana Michigan Power Co [Member]
Commodity
Derivative, Volume Notional Amount | gal		0.6		0.6
Heating Oil and Gasoline [Member] | Ohio Power Co [Member]
Commodity
Derivative, Volume Notional Amount | gal		1.4		1.4
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		0.9
Interest Rate Contract [Member]
Commodity
Derivative, Notional Amount		$ 129,800,000		$ 140,100,000
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
Warrants Held in Investee [Member]
Fair Value of Derivative Instruments
Total Assets		32,000,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		32,000,000
Derivatives and Hedging (Textuals)
Cost of Investment in Privately Held Investee		8,000,000
Vertically Integrated Utilities Revenues [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		800,000		700,000		(10,400,000)
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		9,500,000		25,100,000		38,900,000
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		400,000		100,000		(1,900,000)
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		100,000		500,000		(8,200,000)
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		1,400,000		1,900,000		8,600,000
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		1,200,000		1,600,000		7,600,000
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		100,000		800,000
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		(2,000,000)		(800,000)		1,700,000
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		(600,000)		(200,000)		400,000
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		(200,000)		(100,000)		200,000
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		(200,000)		(100,000)		200,000
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		(300,000)		(200,000)		300,000
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		(200,000)		(100,000)		200,000
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		(300,000)		(100,000)		200,000
Maintenance Expense [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		(2,900,000)		(800,000)		1,900,000
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		(800,000)		(200,000)		400,000
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		(400,000)		(200,000)		400,000
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		(300,000)		(100,000)		200,000
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		(500,000)		(200,000)		400,000
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		(300,000)		(100,000)		200,000
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		(400,000)		(100,000)		200,000
Regulatory Assets [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[11]	(4,800,000)		(3,700,000)		27,900,000
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	[11]	0		700,000		(700,000)
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	[11]	0		300,000		(700,000)
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	[11]	(100,000)		300,000		7,100,000
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	[11]	(6,600,000)		(3,700,000)		24,900,000
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	[11]	0		1,200,000		(1,100,000)
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	[11]	1,400,000		(1,500,000)		(1,200,000)
Regulatory Liabilities [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[11]	114,900,000		102,600,000		222,700,000
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	[11]	400,000		0		(500,000)
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	[11]	20,300,000		2,400,000		135,500,000
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	[11]	12,400,000		24,500,000		11,600,000
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	[11]	12,400,000		10,100,000		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	[11]	39,100,000		34,600,000		37,300,000
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	[11]	20,200,000		26,600,000		11,900,000
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Commodity [Member]
Change in Fair Value Recognized in AOCI		(89,200,000)		(127,200,000)		37,300,000
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		(39,900,000)	[12]	(200,000)	[12]	2,300,000
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		100,000		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		(700,000)		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		0		$ 2,300,000
Fair Value, Inputs, Level 3 [Member]
Fair Value of Derivative Instruments
Total Assets		256,300,000		372,400,000
Total Liabilities		174,800,000		262,500,000
Fair Value, Inputs, Level 3 [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Total Assets		19,900,000		40,500,000
Total Liabilities		600,000		2,800,000
Fair Value, Inputs, Level 3 [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Total Assets		2,500,000		8,000,000
Total Liabilities		400,000		2,200,000
Fair Value, Inputs, Level 3 [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Total Assets		3,300,000		6,500,000
Total Liabilities		1,700,000		5,100,000
Fair Value, Inputs, Level 3 [Member] | Risk Management Contracts [Member]
Fair Value of Derivative Instruments
Total Assets	[4]	252,400,000	[5]	369,200,000	[6]
Total Liabilities	[4]	167,200,000	[5]	224,000,000	[6]
Fair Value, Inputs, Level 3 [Member] | Risk Management Contracts [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Total Assets	[4]	0
Fair Value, Inputs, Level 3 [Member] | Risk Management Contracts [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[4],[7]	19,900,000		40,500,000
Total Liabilities	[4],[7]	600,000		2,800,000
Fair Value, Inputs, Level 3 [Member] | Risk Management Contracts [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[4],[7]	2,500,000		8,000,000
Total Liabilities	[4],[7]	400,000		2,200,000
Fair Value, Inputs, Level 3 [Member] | Risk Management Contracts [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[4],[7]	0
Total Liabilities	[4],[7]	110,300,000		103,600,000
Fair Value, Inputs, Level 3 [Member] | Risk Management Contracts [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Total Assets	[4],[7]	10,300,000		16,300,000
Total Liabilities	[4],[7]			500,000
Fair Value, Inputs, Level 3 [Member] | Risk Management Contracts [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[4],[7]	3,300,000		6,500,000
Total Liabilities	[4],[7]	1,700,000		5,100,000
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				25,000,000
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		(13,000,000)
Fair Value, Inputs, Level 3 [Member] | 2025-2026 [Member]
Maturity Of Net Fair Value Of Risk Management Contracts Prior To Cash Collateral Assets Or Liabilities		14,000,000
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		298,200,000		474,200,000
Total Liabilities		357,800,000		555,300,000
Fair Value, Inputs, Level 2 [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Total Assets		21,800,000
Total Liabilities		22,900,000
Fair Value, Inputs, Level 2 [Member] | Risk Management Contracts [Member]
Fair Value of Derivative Instruments
Total Assets	[4]	258,800,000	[5]	440,100,000	[6]
Total Liabilities	[4]	244,200,000	[5]	450,000,000	[6]
Fair Value, Inputs, Level 2 [Member] | Risk Management Contracts [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Total Assets	[4]	400,000
Fair Value, Inputs, Level 2 [Member] | Risk Management Contracts [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[4],[7]	19,400,000		84,600,000
Total Liabilities	[4],[7]	19,500,000		84,000,000
Fair Value, Inputs, Level 2 [Member] | Risk Management Contracts [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[4],[7]	15,100,000		59,500,000
Total Liabilities	[4],[7]	12,000,000		53,400,000
Fair Value, Inputs, Level 2 [Member] | Risk Management Contracts [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[4],[7]	300,000
Total Liabilities	[4],[7]	0		0
Fair Value, Inputs, Level 2 [Member] | Risk Management Contracts [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Total Assets	[4],[7]	200,000		0
Total Liabilities	[4],[7]			0
Fair Value, Inputs, Level 2 [Member] | Risk Management Contracts [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[4],[7]	100,000		0
Total Liabilities	[4],[7]	0		$ 0
Fair Value, Inputs, Level 2 [Member] | Maturity Period Eight [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] | 2025-2026 [Member]
Maturity Of Net Fair Value Of Risk Management Contracts Prior To Cash Collateral Assets Or Liabilities		$ 11,000,000
[1]	Amounts include $(53) million and $0 as of December 31, 2020 and 2019, respectively, for the fair value hedge adjustment of hedged debt obligations for which hedge accounting has been discontinued
[2]	Amounts included on the balance sheets within Long-term Debt Due within One Year and Long-term Debt, respectively.
[3]	Gain (Loss) is included in Interest Expense on the statements of income.
[4]	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.”
[5]	The December 31, 2020 maturities of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), were as follows: Level 2 matures $3 million in periods 2022-2024, $11 million in periods 2025-2026 and $1 million in periods 2027-2033; Level 3 matures $47 million in 2021, $37 million in periods 2022-2024, $14 million in periods 2025-2026 and $(13) million in periods 2027-2033. Risk management commodity contracts are substantially comprised of power contracts.
[6]	The December 31, 2019 maturities of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), were 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.
[7]	Substantially comprised of power contracts for the Registrant Subsidiaries.
[8]	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.”
[9]	Amounts include counterparty netting of risk management and hedging contracts and associated cash collateral in accordance with the accounting guidance for “Derivatives and Hedging.”
[10]	All derivative contracts subject to a master netting arrangement or similar agreement are offset in the statement of financial position.
[11]	Represents realized and unrealized gains and losses subject to regulatory accounting treatment recorded as either current or noncurrent on the balance sheets.
[12]	The change in fair value includes $6 million and $4 million related to AEP's investment in joint venture wind farms acquired as part of the purchase of Sempra Renewables LLC for the years ended December 31, 2020 and December 31, 2019. See “Sempra Renewables LLC” section of Note 17 for additional information.

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, 2020	Dec. 31, 2019		Dec. 31, 2018
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		$ 31,072.5	$ 26,725.5
Long-term Debt, Fair Value	[1]	37,457	30,172
Other Temporary Investments
Cost		214.9	367.1
Gross Unrealized Gains		31.5	21.4
Gross Unrealized Losses		0	0
Fair Value		246.4	388.5
Debt and Equity Securities Within Other Temporary Investments
Proceeds From Investment Sales		50.9	21.2		$ 0
Purchases of Investments		41.6	45		3.1
Gross Realized Gains on Investment Sales		3.8	0		0
Gross Realized Losses on Investment Sales		0.2	0.4		0
Nuclear Trust Fund Investments
Fair Value		3,306.7	2,975.7
Contractual Maturities, Fair Value of Debt Securities
Fair Value		3,306.7	2,975.7
Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains		1,509.8	1,205.9
Other-Than-Temporary Impairments		(9.2)	(7.9)
Securities Activity Within the Decommissioning and SNF Trusts
Proceeds from Investment Sales		1,593.4	1,473		2,010
Purchases of Investments		1,637.2	1,531		2,064.7
Gross Realized Gains on Investment Sales		26.4	76.5		47.5
Gross Realized Losses on Investment Sales		26.1	24.3		32.8
Contractual Maturities, Fair Value of Debt Securities
Within 1 year		294.8
After 1 year through 5 years		371.3
After 5 years through 10 years		214.4
After 10 years		345.7
Fair Value Measurements (Textuals)
Adjusted Cost of Debt Securities		1,100	1,100
Adjusted Cost of Domestic Equity Securities		654	623
AEP Texas Inc. [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		4,820.4	4,558.4
Long-term Debt, Fair Value		5,682.6	4,981.5
AEP Transmission Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		3,948.5	3,427.3
Long-term Debt, Fair Value		4,984.3	3,868
Appalachian Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		4,834.1	4,363.8
Long-term Debt, Fair Value		6,391.8	5,253.1
Indiana Michigan Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		3,029.9	3,050.2
Long-term Debt, Fair Value		3,775.3	3,453.8
Nuclear Trust Fund Investments
Fair Value		3,306.7	2,975.7
Contractual Maturities, Fair Value of Debt Securities
Fair Value		3,306.7	2,975.7
Indiana Michigan Power Co [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains		1,509.8	1,205.9
Other-Than-Temporary Impairments		(9.2)	(7.9)
Securities Activity Within the Decommissioning and SNF Trusts
Proceeds from Investment Sales		1,593.4	1,473		2,010
Purchases of Investments		1,637.2	1,531		2,064.7
Gross Realized Gains on Investment Sales		26.4	76.5		47.5
Gross Realized Losses on Investment Sales		26.1	24.3		$ 32.8
Contractual Maturities, Fair Value of Debt Securities
Within 1 year		294.8
After 1 year through 5 years		371.3
After 5 years through 10 years		214.4
After 10 years		345.7
Fair Value Measurements (Textuals)
Adjusted Cost of Debt Securities		1,100	1,100
Adjusted Cost of Domestic Equity Securities		654	623
Ohio Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		2,430.2	2,082
Long-term Debt, Fair Value		3,154.9	2,554.3
Public Service Co Of Oklahoma [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		1,373.8	1,386.2
Long-term Debt, Fair Value		1,732.1	1,603.3
Southwestern Electric Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		2,636.4	2,655.6
Long-term Debt, Fair Value		3,210.1	2,927.9
Cash [Member]
Other Temporary Investments
Cost	[2]	68.3	214.7
Gross Unrealized Gains	[2]	0	0
Gross Unrealized Losses	[2]	0	0
Fair Value	[2],[3]	68.3	214.7
Fixed Income Funds [Member]
Nuclear Trust Fund Investments
Fair Value		1,226.2	1,192.5
Contractual Maturities, Fair Value of Debt Securities
Fair Value		1,226.2	1,192.5
Fixed Income Funds [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains		109	61.5
Other-Than-Temporary Impairments		(9.2)	(7.9)
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments
Fair Value		1,226.2	1,192.5
Contractual Maturities, Fair Value of Debt Securities
Fair Value		1,226.2	1,192.5
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains		109	61.5
Other-Than-Temporary Impairments		(9.2)	(7.9)
Mutual Funds Fixed Income [Member]
Other Temporary Investments
Cost	[4]	120.7	123.2
Gross Unrealized Gains	[4]	2.8	0.1
Gross Unrealized Losses	[4]	0	0
Fair Value	[4]	123.5	123.3
Mutual Funds Equity [Member]
Other Temporary Investments
Cost		25.9	29.2
Gross Unrealized Gains		28.7	21.3
Gross Unrealized Losses		0	0
Fair Value		54.6	50.5
Domestic [Member]
Nuclear Trust Fund Investments
Fair Value	[5]	2,054.7	1,767.9
Contractual Maturities, Fair Value of Debt Securities
Fair Value	[5]	2,054.7	1,767.9
Domestic [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Unrealized Gain on Securities		1,400	1,100
Unrealized Loss on Securities		9	5
Nuclear Trust Fund Investments
Gross Unrealized Gains	[6]	1,400.8	1,144.4
Other-Than-Temporary Impairments		0	0
Domestic [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments
Fair Value	[5]	2,054.7	1,767.9
Contractual Maturities, Fair Value of Debt Securities
Fair Value	[5]	2,054.7	1,767.9
Domestic [Member] | Indiana Michigan Power Co [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Unrealized Gain on Securities		1,400	1,100
Unrealized Loss on Securities		9	5
Nuclear Trust Fund Investments
Gross Unrealized Gains	[6]	1,400.8	1,144.4
Other-Than-Temporary Impairments		0	0
Cash and Cash Equivalents [Member]
Nuclear Trust Fund Investments
Fair Value	[7]	25.8	15.3
Contractual Maturities, Fair Value of Debt Securities
Fair Value	[7]	25.8	15.3
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	[7]	25.8	15.3
Contractual Maturities, Fair Value of Debt Securities
Fair Value	[7]	25.8	15.3
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		1,025.6	1,112.5
Contractual Maturities, Fair Value of Debt Securities
Fair Value		1,025.6	1,112.5
US Government Agencies Debt Securities [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains		98.5	55.5
Other-Than-Temporary Impairments		(7.1)	(6.1)
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments
Fair Value		1,025.6	1,112.5
Contractual Maturities, Fair Value of Debt Securities
Fair Value		1,025.6	1,112.5
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		98.5	55.5
Other-Than-Temporary Impairments		(7.1)	(6.1)
Corporate Debt [Member]
Nuclear Trust Fund Investments
Fair Value		86.3	72.4
Contractual Maturities, Fair Value of Debt Securities
Fair Value		86.3	72.4
Corporate Debt [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains		9.6	5.3
Other-Than-Temporary Impairments		(1.7)	(1.6)
Corporate Debt [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments
Fair Value		86.3	72.4
Contractual Maturities, Fair Value of Debt Securities
Fair Value		86.3	72.4
Corporate Debt [Member] | Indiana Michigan Power Co [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains		9.6	5.3
Other-Than-Temporary Impairments		(1.7)	(1.6)
State and Local Jurisdiction
Nuclear Trust Fund Investments
Fair Value		114.3	7.6
Contractual Maturities, Fair Value of Debt Securities
Fair Value		114.3	7.6
State and Local Jurisdiction | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains		0.9	0.7
Other-Than-Temporary Impairments		(0.4)	(0.2)
State and Local Jurisdiction | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments
Fair Value		114.3	7.6
Contractual Maturities, Fair Value of Debt Securities
Fair Value		114.3	7.6
State and Local Jurisdiction | Indiana Michigan Power Co [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains		0.9	0.7
Other-Than-Temporary Impairments		(0.4)	(0.2)
Equity units [Member]
Book Values and Fair Values of Long - term Debt
Long-term Debt, Fair Value		$ 1,700	$ 871	[1]
[1]	The fair value amounts include debt related to AEP’s Equity Units and had a fair value of $1.7 billion and $871 million as of December 31, 2020 and 2019, respectively. See “Equity Units” section of Note 14 for additional information.
[2]	Primarily represents amounts held for the repayment of debt.
[3]	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.
[4]	Primarily short and intermediate maturities which may be sold and do not contain maturity dates.
[5]	Amounts represent publicly-traded equity securities and equity-based mutual funds.
[6]	Amount reported as Gross Unrealized Gains includes unrealized gains of $1.4 billion and $1.1 billion and unrealized losses of $9 million and $5 million as of December 31, 2020 and 2019, respectively.
[7]	Amounts in “Other” column primarily represent accrued interest receivables from financial institutions.  Level 1 amounts primarily represent investments in money market funds.

Fair Value Financial Assets Lia

Fair Value Financial Assets Liabilities (Details) - USD ($)		12 Months Ended
		Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Assets, Fair Value Disclosure
Other Temporary Investments		$ 246,400,000		$ 388,500,000
Risk Management Assets
Derivative Assets		336,900,000		439,400,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		3,306,700,000		2,975,700,000
Total Assets		3,921,800,000		3,803,600,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		311,600,000		376,100,000
Changes in the Fair Value of Net Trading Derivatives and Other Investments
Beginning Balance		109,900,000		131,200,000		$ 40,300,000
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	[1],[2]	39,500,000		15,800,000		148,900,000
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	[1]	35,300,000		(100,000)		9,800,000
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	[3]	13,800,000		(15,100,000)		15,700,000
Settlements		(113,100,000)		(117,600,000)		(214,000,000)
Transfers into Level 3	[4],[5]	(3,800,000)		(600,000)		15,800,000
Transfers out of Level 3	[5]	5,600,000		35,600,000		(1,600,000)
Changes in Fair Value Allocated to Regulated Jurisdiction	[6]	26,100,000		60,700,000		116,300,000
Ending Balance		113,300,000		109,900,000		131,200,000
Other [Member]
Assets, Fair Value Disclosure
Other Temporary Investments		10,500,000		17,100,000
Risk Management Assets
Derivative Assets		(218,500,000)		(411,200,000)
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		9,000,000		8,600,000
Total Assets		(199,000,000)		(385,500,000)
Liabilities, Fair Value Disclosure
Derivative Liabilities		(221,900,000)		(445,500,000)
Level 1 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments		235,900,000		371,400,000
Risk Management Assets
Derivative Assets		900,000		4,000,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		2,071,500,000		1,774,600,000
Total Assets		2,308,300,000		2,150,000,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		900,000		3,800,000
Level 2 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments		0		0
Risk Management Assets
Derivative Assets		298,200,000		474,200,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,226,200,000		1,192,500,000
Total Assets		1,524,400,000		1,666,700,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		357,800,000		555,300,000
Level 3 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments		0		0
Risk Management Assets
Derivative Assets		256,300,000		372,400,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0		0
Total Assets		288,100,000		372,400,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		174,800,000		262,500,000
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
2021 [Member] | Level 3 [Member]
Fair Value Measurements 1 (Textuals)
Maturity Of Net Fair Value Of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		47,000,000
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
2022 - 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		3,000,000
2022 - 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		37,000,000
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
2025-2026 [Member] | Level 2 [Member]
Fair Value Measurements 1 (Textuals)
Maturity Of Net Fair Value Of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		11,000,000
2025-2026 [Member] | Level 3 [Member]
Fair Value Measurements 1 (Textuals)
Maturity Of Net Fair Value Of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		14,000,000
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)
2027 - 2033 [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
2027 - 2033 [Member] | Level 3 [Member]
Fair Value Measurements 1 (Textuals)
Maturity Of Net Fair Value Of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		(13,000,000)
Risk Management Commodity Contracts [Member]
Risk Management Assets
Derivative Assets	[7]	322,100,000	[8]	408,800,000	[9]
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7]	218,900,000	[8]	239,000,000	[9]
Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Derivative Assets	[7]	(190,000,000)	[8]	(404,500,000)	[9]
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7]	(193,400,000)	[8]	(438,800,000)	[9]
Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Derivative Assets	[7]	900,000	[8]	4,000,000	[9]
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7]	900,000	[8]	3,800,000	[9]
Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Derivative Assets	[7]	258,800,000	[8]	440,100,000	[9]
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7]	244,200,000	[8]	450,000,000	[9]
Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets	[7]	252,400,000	[8]	369,200,000	[9]
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7]	167,200,000	[8]	224,000,000	[9]
Energy Contracts [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets		213,500,000		296,700,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		169,700,000		249,300,000
Energy Contracts [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10]	5.33		(0.05)
Energy Contracts [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10]	100.47		177.30
Energy Contracts [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10],[11]	32.73		31.31
Natural Gas Contracts [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets		0		0
Liabilities, Fair Value Disclosure
Derivative Liabilities		1,700,000		4,900,000
Natural Gas Contracts [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[12]	2.18		1.89
Natural Gas Contracts [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[12]	2.77		2.51
Natural Gas Contracts [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[11],[12]	2.40		2.19
FTRs [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets		42,800,000		75,700,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		3,400,000		8,300,000
FTRs [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10]	(15.08)		(8.52)
FTRs [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10]	9.66		9.34
FTRs [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10],[11]	0.19		0.42
Commodity Hedges [Member]
Risk Management Assets
Derivative Assets	[7]	9,800,000		11,500,000
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7]	85,200,000		137,100,000
Commodity Hedges [Member] | Other [Member]
Risk Management Assets
Derivative Assets	[7]	(28,500,000)		(6,700,000)
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7]	(28,500,000)		(6,700,000)
Commodity Hedges [Member] | Level 1 [Member]
Risk Management Assets
Derivative Assets	[7]	0		0
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7]	0		0
Commodity Hedges [Member] | Level 2 [Member]
Risk Management Assets
Derivative Assets	[7]	34,400,000		15,000,000
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7]	106,100,000		105,300,000
Commodity Hedges [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets	[7]	3,900,000		3,200,000
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7]	7,600,000		38,500,000
Interest Rate Foreign Currency Hedges [Member]
Risk Management Assets
Derivative Assets		2,400,000		4,600,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		3,400,000
Interest Rate Foreign Currency Hedges [Member] | Other [Member]
Risk Management Assets
Derivative Assets		0		0
Liabilities, Fair Value Disclosure
Derivative Liabilities		0
Interest Rate Foreign Currency Hedges [Member] | Level 1 [Member]
Risk Management Assets
Derivative Assets		0		0
Liabilities, Fair Value Disclosure
Derivative Liabilities		0
Interest Rate Foreign Currency Hedges [Member] | Level 2 [Member]
Risk Management Assets
Derivative Assets		2,400,000		4,600,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		3,400,000
Interest Rate Foreign Currency Hedges [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets		0		0
Liabilities, Fair Value Disclosure
Derivative Liabilities		0
Fair Value Hedges [Member]
Risk Management Assets
Derivative Assets		2,600,000		14,500,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		4,100,000
Fair Value Hedges [Member] | Other [Member]
Risk Management Assets
Derivative Assets		0		0
Liabilities, Fair Value Disclosure
Derivative Liabilities		0
Fair Value Hedges [Member] | Level 1 [Member]
Risk Management Assets
Derivative Assets		0		0
Liabilities, Fair Value Disclosure
Derivative Liabilities		0
Fair Value Hedges [Member] | Level 2 [Member]
Risk Management Assets
Derivative Assets		2,600,000		14,500,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		4,100,000
Fair Value Hedges [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets		0		0
Liabilities, Fair Value Disclosure
Derivative Liabilities		0
Other Investments [Member]
Risk Management Assets
Derivative Assets	[13]	31,800,000
Other Investments [Member] | Other [Member]
Risk Management Assets
Derivative Assets	[13]	0
Other Investments [Member] | Level 1 [Member]
Risk Management Assets
Derivative Assets	[13]	0
Other Investments [Member] | Level 2 [Member]
Risk Management Assets
Derivative Assets	[13]	0
Other Investments [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets	[13]	31,800,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		0
Other Investments [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[14]	0.10
Other Investments [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[14]	0.20
Other Investments [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[14]	0.15
AEP Texas Inc. [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		28,700,000		154,700,000
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		28,700,000
AEP Texas Inc. [Member] | Other [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0		0
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		(400,000)
AEP Texas Inc. [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		28,700,000		154,700,000
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		28,700,000
AEP Texas Inc. [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0		0
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		400,000
AEP Texas Inc. [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0		0
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		0
AEP Texas Inc. [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Derivative Assets	[7]	0
AEP Texas Inc. [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Derivative Assets	[7]	(400,000)
AEP Texas Inc. [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Derivative Assets	[7]	0
AEP Texas Inc. [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Derivative Assets	[7]	400,000
AEP Texas Inc. [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets	[7]	0
Appalachian Power Co [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		16,900,000		23,500,000
Risk Management Assets
Derivative Assets		22,500,000
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		39,400,000		63,000,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		4,700,000
Changes in the Fair Value of Net Trading Derivatives and Other Investments
Beginning Balance		37,700,000		57,800,000		24,700,000
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	[1],[2]	13,200,000		(13,900,000)		104,100,000
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	[1]	0		0		0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	[3]	0		0		0
Settlements		(51,600,000)		(42,500,000)		(127,900,000)
Transfers into Level 3	[4],[5]	0		(500,000)		0
Transfers out of Level 3	[5]	700,000		(700,000)		0
Changes in Fair Value Allocated to Regulated Jurisdiction	[6]	19,300,000		37,500,000		56,900,000
Ending Balance		19,300,000		37,700,000		57,800,000
Appalachian Power Co [Member] | Other [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0		0
Risk Management Assets
Derivative Assets		(19,200,000)
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		(19,200,000)		(85,600,000)
Liabilities, Fair Value Disclosure
Derivative Liabilities		(18,800,000)
Appalachian Power Co [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		16,900,000		23,500,000
Risk Management Assets
Derivative Assets		0
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		16,900,000		23,500,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		0
Appalachian Power Co [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0		0
Risk Management Assets
Derivative Assets		21,800,000
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		21,800,000		84,600,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		22,900,000
Appalachian Power Co [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0		0
Risk Management Assets
Derivative Assets		19,900,000		40,500,000
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		19,900,000		40,500,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		600,000		2,800,000
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Derivative Assets	[7],[15]	20,100,000		39,500,000
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]	1,300,000		1,900,000
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Derivative Assets	[7],[15]	(19,200,000)		(85,600,000)
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]	(18,800,000)		(84,900,000)
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Derivative Assets	[7],[15]	0		0
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]	0		0
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Derivative Assets	[7],[15]	19,400,000		84,600,000
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]	19,500,000		84,000,000
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets	[7],[15]	19,900,000		40,500,000
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]	600,000		2,800,000
Appalachian Power Co [Member] | Energy Contracts [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets		1,000,000		5,700,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		600,000		2,600,000
Appalachian Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10]	10.84		12.70
Appalachian Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10]	41.09		41.20
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	[10],[11]	25.08		25.92
Appalachian Power Co [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets		18,900,000		34,800,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		0		200,000
Appalachian Power Co [Member] | FTRs [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10]	0.04		(0.14)
Appalachian Power Co [Member] | FTRs [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10]	5.61		7.08
Appalachian Power Co [Member] | FTRs [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10],[11]	1.13		1.70
Appalachian Power Co [Member] | Interest Rate Foreign Currency Hedges [Member]
Risk Management Assets
Derivative Assets		2,400,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		3,400,000
Appalachian Power Co [Member] | Interest Rate Foreign Currency Hedges [Member] | Other [Member]
Risk Management Assets
Derivative Assets		0
Liabilities, Fair Value Disclosure
Derivative Liabilities		0
Appalachian Power Co [Member] | Interest Rate Foreign Currency Hedges [Member] | Level 1 [Member]
Risk Management Assets
Derivative Assets		0
Liabilities, Fair Value Disclosure
Derivative Liabilities		0
Appalachian Power Co [Member] | Interest Rate Foreign Currency Hedges [Member] | Level 2 [Member]
Risk Management Assets
Derivative Assets		2,400,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		3,400,000
Appalachian Power Co [Member] | Interest Rate Foreign Currency Hedges [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets		0
Liabilities, Fair Value Disclosure
Derivative Liabilities		0
Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		3,306,700,000		2,975,700,000
Total Assets		3,310,400,000		2,985,600,000
Changes in the Fair Value of Net Trading Derivatives and Other Investments
Beginning Balance		5,800,000		8,900,000		7,600,000
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	[1],[2]	2,500,000		4,700,000		14,200,000
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	[1]	0		0		0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	[3]	0		0		0
Settlements		(8,600,000)		(13,000,000)		(21,300,000)
Transfers into Level 3	[4],[5]	0		(300,000)		0
Transfers out of Level 3	[5]	400,000		(400,000)		(300,000)
Changes in Fair Value Allocated to Regulated Jurisdiction	[6]	2,000,000		5,900,000		8,700,000
Ending Balance		2,100,000		5,800,000		8,900,000
Indiana Michigan Power Co [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		9,000,000		8,600,000
Total Assets		(4,900,000)		(49,000,000)
Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		2,071,500,000		1,774,600,000
Total Assets		2,071,500,000		1,774,600,000
Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,226,200,000		1,192,500,000
Total Assets		1,241,300,000		1,252,000,000
Indiana Michigan Power Co [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets		2,500,000		8,000,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0		0
Total Assets		2,500,000		8,000,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		400,000		2,200,000
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Derivative Assets	[7],[15]	3,700,000		9,900,000
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]	200,000		500,000
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Derivative Assets	[7],[15]	(13,900,000)		(57,600,000)
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]	(12,200,000)		(55,100,000)
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Derivative Assets	[7],[15]	0		0
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]	0		0
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Derivative Assets	[7],[15]	15,100,000		59,500,000
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]	12,000,000		53,400,000
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets	[7],[15]	2,500,000		8,000,000
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]	400,000		2,200,000
Indiana Michigan Power Co [Member] | Energy Contracts [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets		600,000		3,400,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		300,000		1,500,000
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	[10]	10.84		12.70
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	[10]	41.09		41.20
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	[10],[11]	25.08		25.92
Indiana Michigan Power Co [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets		1,900,000		4,600,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		100,000		700,000
Indiana Michigan Power Co [Member] | FTRs [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10]	(1.96)		(0.75)
Indiana Michigan Power Co [Member] | FTRs [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10]	3.69		4.07
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	[10],[11]	0.33		0.74
Ohio Power Co [Member]
Changes in the Fair Value of Net Trading Derivatives and Other Investments
Beginning Balance		(103,600,000)		(99,400,000)		(132,400,000)
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	[1],[2]	(1,600,000)		(900,000)		1,800,000
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	[1]	0		0		0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	[3]	0		0		0
Settlements		8,900,000		6,600,000		4,600,000
Transfers into Level 3	[4],[5]	0		0		0
Transfers out of Level 3	[5]	0		0		0
Changes in Fair Value Allocated to Regulated Jurisdiction	[6]	(14,000,000)		(9,900,000)		26,600,000
Ending Balance		(110,300,000)		(103,600,000)		(99,400,000)
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Derivative Assets	[7],[15]	0
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]	110,300,000		103,600,000
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Derivative Assets	[7],[15]	(300,000)
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]	0		0
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Derivative Assets	[7],[15]	0
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]	0		0
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Derivative Assets	[7],[15]	300,000
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]	0		0
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets	[7],[15]	0
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]	110,300,000		103,600,000
Ohio Power Co [Member] | Energy Contracts [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets		0		0
Liabilities, Fair Value Disclosure
Derivative Liabilities		110,300,000		103,600,000
Ohio Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10]	16.19		29.23
Ohio Power Co [Member] | Energy Contracts [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10]	46.98		61.43
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	[10],[11]	28.30		42.46
Public Service Co Of Oklahoma [Member]
Changes in the Fair Value of Net Trading Derivatives and Other Investments
Beginning Balance		15,800,000		9,500,000		6,200,000
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	[1],[2]	11,900,000		13,500,000		18,100,000
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	[1]	0		0		0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	[3]	0		0		0
Settlements		(27,600,000)		(23,000,000)		(24,300,000)
Transfers into Level 3	[4],[5]	0		0		0
Transfers out of Level 3	[5]	0		0		0
Changes in Fair Value Allocated to Regulated Jurisdiction	[6]	10,200,000		15,800,000		9,500,000
Ending Balance		10,300,000		15,800,000		9,500,000
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Derivative Assets	[7],[15]	10,300,000		15,800,000
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]			0
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Derivative Assets	[7],[15]	(200,000)		(500,000)
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]			(500,000)
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Derivative Assets	[7],[15]	0		0
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]			0
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Derivative Assets	[7],[15]	200,000		0
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]			0
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets	[7],[15]	10,300,000		16,300,000
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]			500,000
Public Service Co Of Oklahoma [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets		10,300,000		16,300,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		0		500,000
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	[10]	(6.93)		(8.52)
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	[10]	0.48		0.85
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	[10],[11]	(1.93)		(2.31)
Southwestern Electric Power Co [Member]
Changes in the Fair Value of Net Trading Derivatives and Other Investments
Beginning Balance		1,400,000		2,300,000		5,900,000
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	[1],[2]	2,800,000		6,000,000		(4,800,000)
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	[1]	0		0		0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	[3]	0		0		0
Settlements		(6,600,000)		(9,600,000)		(2,100,000)
Transfers into Level 3	[4],[5]	0		0		0
Transfers out of Level 3	[5]	0		0		0
Changes in Fair Value Allocated to Regulated Jurisdiction	[6]	4,000,000		2,700,000		3,300,000
Ending Balance		1,600,000		1,400,000		$ 2,300,000
Southwestern Electric Power Co [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets		3,300,000		6,500,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		1,700,000		5,100,000
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Derivative Assets	[7],[15]	3,200,000		6,400,000
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]	1,700,000		5,000,000
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Derivative Assets	[7],[15]	(200,000)		(100,000)
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]	0		(100,000)
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Derivative Assets	[7],[15]	0		0
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]	0		0
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Derivative Assets	[7],[15]	100,000		0
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]	0		0
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets	[7],[15]	3,300,000		6,500,000
Liabilities, Fair Value Disclosure
Derivative Liabilities	[7],[15]	1,700,000		5,100,000
Southwestern Electric Power Co [Member] | Natural Gas Contracts [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets		0		0
Liabilities, Fair Value Disclosure
Derivative Liabilities		1,700,000		4,900,000
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	[12]	2.18		1.89
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	[12]	2.77		2.51
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	[11],[12]	2.41		2.18
Southwestern Electric Power Co [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Derivative Assets		3,300,000		6,500,000
Liabilities, Fair Value Disclosure
Derivative Liabilities		0		200,000
Southwestern Electric Power Co [Member] | FTRs [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10]	(6.93)		(8.52)
Southwestern Electric Power Co [Member] | FTRs [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10]	0.48		0.85
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	[10],[11]	(1.93)		(2.31)
Cash [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	[16],[17]	68,300,000		214,700,000
Cash [Member] | Other [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	[16]	10,500,000		17,100,000
Cash [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	[16]	57,800,000		197,600,000
Cash [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	[16]	0		0
Cash [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	[16]	0		0
Mutual Funds Fixed Income [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	[18]	123,500,000		123,300,000
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		123,500,000		123,300,000
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	[19]	54,600,000		50,500,000
Mutual Funds Equity [Member] | Other [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	[19]	0		0
Mutual Funds Equity [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	[19]	54,600,000		50,500,000
Mutual Funds Equity [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	[19]	0		0
Mutual Funds Equity [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Other Temporary Investments	[19]	0		0
Cash and Cash Equivalents [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[20]	25,800,000		15,300,000
Cash and Cash Equivalents [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[20]	9,000,000		8,600,000
Cash and Cash Equivalents [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[20]	16,800,000		6,700,000
Cash and Cash Equivalents [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[20]	0		0
Cash and Cash Equivalents [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[20]	0		0
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[20]	25,800,000		15,300,000
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[20]	9,000,000		8,600,000
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	[20]	16,800,000		6,700,000
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	[20]	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	[20]	0		0
US Government Agencies Debt Securities [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,025,600,000		1,112,500,000
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		1,025,600,000		1,112,500,000
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		1,025,600,000		1,112,500,000
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		1,025,600,000		1,112,500,000
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		86,300,000		72,400,000
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		86,300,000		72,400,000
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		86,300,000		72,400,000
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		86,300,000		72,400,000
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
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		114,300,000		7,600,000
State and Local Jurisdiction | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0		0
State and Local Jurisdiction | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0		0
State and Local Jurisdiction | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		114,300,000		7,600,000
State and Local Jurisdiction | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0		0
State and Local Jurisdiction | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		114,300,000		7,600,000
State and Local Jurisdiction | 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 | 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 | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		114,300,000		7,600,000
State and Local Jurisdiction | 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		1,226,200,000		1,192,500,000
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		1,226,200,000		1,192,500,000
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		1,226,200,000		1,192,500,000
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		1,226,200,000		1,192,500,000
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	[19]	2,054,700,000		1,767,900,000
Domestic [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[19]	0		0
Domestic [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[19]	2,054,700,000		1,767,900,000
Domestic [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[19]	0		0
Domestic [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[19]	0		0
Domestic [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[19]	2,054,700,000		1,767,900,000
Domestic [Member] | Indiana Michigan Power Co [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[19]	0		0
Domestic [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[19]	2,054,700,000		1,767,900,000
Domestic [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[19]	0		0
Domestic [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[19]	$ 0		$ 0
[1]	Included in revenues on the statements of income.
[2]	Represents the change in fair value between the beginning of the reporting period and the settlement of the risk management commodity contract.
[3]	Included in cash flow hedges on the statements of comprehensive income.
[4]	Represents existing assets or liabilities that were previously categorized as Level 2.
[5]	Transfers are recognized based on their value at the beginning of the reporting period that the transfer occurred.
[6]	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.
[7]	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.”
[8]	The December 31, 2020 maturities of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), were as follows: Level 2 matures $3 million in periods 2022-2024, $11 million in periods 2025-2026 and $1 million in periods 2027-2033; Level 3 matures $47 million in 2021, $37 million in periods 2022-2024, $14 million in periods 2025-2026 and $(13) million in periods 2027-2033. Risk management commodity contracts are substantially comprised of power contracts.
[9]	The December 31, 2019 maturities of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), were 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.
[10]	Represents market prices in dollars per MWh.
[11]	The weighted-average is the product of the forward market price of the underlying commodity and volume weighted by term.
[12]	Represents market prices in dollars per MMBtu.
[13]	See “Warrants Held in Investee” section of Note 10 for additional information.
[14]	Represents percentage discount applied to the publically available share price.
[15]	Substantially comprised of power contracts for the Registrant Subsidiaries.
[16]	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.
[17]	Primarily represents amounts held for the repayment of debt.
[18]	Primarily short and intermediate maturities which may be sold and do not contain maturity dates.
[19]	Amounts represent publicly-traded equity securities and equity-based mutual funds.
[20]	Amounts in “Other” column primarily represent accrued interest receivables from financial institutions.  Level 1 amounts primarily represent investments in money market funds.

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2014
Federal:
Current	$ (138.2)	$ (7.4)	$ (31.7)
Deferred	146.9	(71.6)	122
Total Federal	8.7	(79)	90.3
Current	(16.7)	4.4	30.8
Deferred	48.5	61.7	(5.8)
Total State and Local	31.8	66.1	25
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)	40.5	(12.9)	115.3
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income	2,196.7	1,919.8	1,931.3
Less: Equity Earnings – Dolet Hills	(91.1)	(72.1)	(73.1)
Income Tax Expense (Benefit)	40.5	(12.9)	115.3
Pretax Income	2,234.3	1,903.9	2,043.9
Income Taxes on Pretax Income at Statutory Rate (21%)	$ 469.2	$ 399.8	$ 429.2
Federal Statutory Income Tax Rate	21.00%	21.00%	21.00%	35.00%	35.00%
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation	$ 26.5	$ 20.4	$ 24.6
Investment Tax Credit Amortization	(18.8)	(13)	(20.4)
Production Tax Credits	(83.1)	(59.6)	(10.3)
State and Local Income Taxes, Net	25.1	52.2	19.7
Removal Costs	(18.6)	(22.2)	(18.6)
AFUDC	(32.5)	(37.1)	(29.4)
Tax Reform Adjustments	0	0	(10.9)
Tax Reform Excess ADIT Reversal	(268.2)	(353.2)	(257.2)
CARES Act Provision	(48)	0	0
Other	(11.1)	(0.2)	(11.4)
Income Tax Expense (Benefit)	$ 40.5	$ (12.9)	$ 115.3
Effective Income Tax Rate	1.80%	(0.70%)	5.60%
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets	$ 3,259.7	$ 3,246.1
Deferred Tax Liabilities	(11,500.6)	(10,834.3)
Property Related Temporary Differences	(7,340.5)	(6,602.9)
Amounts Due from Customers for Future Federal Income Taxes	1,075.8	1,173.5
Deferred State Income Taxes	(1,317.6)	(1,198)
Securitized Assets	(140)	(178.7)
Regulatory Assets	(391.6)	(371.1)
Accrued Nuclear Decommissioning	(626.4)	(557.4)
Net Operating Loss Carryforward	112.9	77.6
Tax Credit Carryforward	323.6	247.2
Operating Lease Liability	183.7	182.6
Investment in Partnership	(362)	(446.6)
All Other, Net	241.2	85.6
Net Deferred Tax Liabilities	(8,240.9)	(7,588.2)
Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits
Balance at January 1,	24.1	14.6	$ 86.6
Increase - Tax Positions Taken During a Prior Period	0.6	8.8	0.1
Decrease - Tax Positions Taken During a Prior Period	(14.5)	(2.1)	0
Increase - Tax Positions Taken During the Current Year	3	2.8	0
Decrease - Tax Positions Taken During the Current Year	0	0	0
Decrease - Settlements with Taxing Authorities	0	0	(71)
Decrease - Lapse of the Applicable Statute of Limitations	0	0	(1.1)
Balance at December 31,	13.2	24.1	14.6	$ 86.6
Tax Contingency [Abstract]
Unrecognized Tax Benefits, if Recognized - Amount	$ 12	20	12
Income Taxes (Textuals) [Abstract]
Period with No Change in Unrecognized Tax Benefits	12 months
Income Tax Expense (Benefit)	$ 40.5	(12.9)	115.3
Proceeds from Income Tax Refunds	20
Income Taxes Receivable	95
Tax Cuts and Jobs Act, Change in Tax Rate, Deferred Tax Asset, Income Tax Expense	$ 48
Meals and Entertainment, Deductibility, Percentage	100.00%
Deferred Tax Liabilities, Property, Plant and Equipment, Percentage	100.00%
Effective Income Tax Rate Reconciliation, Deduction, Percent	10.00%
Tax Cuts and Jobs Act, Non Deductible Executive Compensation	$ 1
Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date	Dec. 31, 2036
Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date	Dec. 31, 2040
AEP Texas Inc. [Member]
Federal:
Current	$ 5.2	(31.8)	37
Deferred	(15.4)	(24.7)	(17.9)
Total Federal	(10.2)	(56.5)	19.1
Current	(0.1)	2.9	1.8
Deferred	(0.9)	0	(0.1)
Total State and Local	(1)	2.9	1.7
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)	(11.2)	(53.6)	20.8
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income	241	178.3	211.3
Income Tax Expense (Benefit)	(11.2)	(53.6)	20.8
Pretax Income	229.8	124.7	232.1
Income Taxes on Pretax Income at Statutory Rate (21%)	$ 48.3	$ 26.2	$ 48.7
Federal Statutory Income Tax Rate	21.00%	21.00%	21.00%	35.00%
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation	$ 1	$ 1	$ 0.7
Investment Tax Credit Amortization	(1.1)	(1.2)	(2.3)
State and Local Income Taxes, Net	(0.8)	2.3	1.3
AFUDC	(4.1)	(3.2)	(4.2)
Parent Company Loss Benefit	(4.5)	(3.8)	(3)
Tax Reform Adjustments	0	0	(11)
Tax Reform Excess ADIT Reversal	(47.9)	(73.4)	(11.8)
Other	(2.1)	(1.5)	2.4
Income Tax Expense (Benefit)	$ (11.2)	$ (53.6)	$ 20.8
Effective Income Tax Rate	(4.90%)	(43.00%)	9.00%
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets	$ 183.6	$ 220
Deferred Tax Liabilities	(1,200.3)	(1,185.4)
Property Related Temporary Differences	(1,039.6)	(973.5)
Amounts Due from Customers for Future Federal Income Taxes	114.4	126.7
Deferred State Income Taxes	(29.1)	(27.5)
Securitized Transition Assets	(90.2)	(124.3)
Regulatory Assets	(47.4)	(51.2)
Operating Lease Liability	18	17.2
All Other, Net	57.2	67.2
Net Deferred Tax Liabilities	(1,016.7)	(965.4)
Income Taxes (Textuals) [Abstract]
Income Tax Expense (Benefit)	$ (11.2)	(53.6)	$ 20.8
AEP Texas Inc. [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date	Dec. 31, 2036
AEP Texas Inc. [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date	Dec. 31, 2040
AEP Transmission Co [Member]
Federal:
Current	$ 22.2	23.7	(14.2)
Deferred	65.4	71.7	82.3
Total Federal	87.6	95.4	68.1
Current	2.8	2.4	(0.6)
Deferred	16.3	19.6	16.6
Total State and Local	19.1	22	16
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)	106.7	117.4	84.1
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income	423.4	439.7	315.9
Income Tax Expense (Benefit)	106.7	117.4	84.1
Pretax Income	530.1	557.1	400
Income Taxes on Pretax Income at Statutory Rate (21%)	$ 111.3	$ 117	$ 84
Federal Statutory Income Tax Rate	21.00%	21.00%	21.00%	35.00%
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
State and Local Income Taxes, Net	$ 15.1	$ 17.4	$ 12.6
AFUDC	(15.5)	(17.7)	(14.1)
Parent Company Loss Benefit	(7)	(4.2)	(0.6)
Other	2.8	4.9	2.2
Income Tax Expense (Benefit)	$ 106.7	$ 117.4	$ 84.1
Effective Income Tax Rate	20.10%	21.10%	21.00%
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets	$ 166.5	$ 162.9
Deferred Tax Liabilities	(1,073.4)	(980.7)
Property Related Temporary Differences	(937.8)	(847.1)
Amounts Due from Customers for Future Federal Income Taxes	118.9	119.9
Deferred State Income Taxes	(98.3)	(86.1)
Net Operating Loss Carryforward	13.2	12.3
All Other, Net	(2.9)	(16.8)
Net Deferred Tax Liabilities	(906.9)	(817.8)
Income Taxes (Textuals) [Abstract]
Income Tax Expense (Benefit)	$ 106.7	117.4	$ 84.1
AEP Transmission Co [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date	Dec. 31, 2036
AEP Transmission Co [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date	Dec. 31, 2040
Appalachian Power Co [Member]
Federal:
Current	$ 21.4	36.7	(31.9)
Deferred	(27.1)	(126.1)	(24.5)
Total Federal	(5.7)	(89.4)	(56.4)
Current	9.3	12	3.7
Deferred	0.7	(0.6)	7.8
Total State and Local	10	11.4	11.5
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)	4.3	(78)	(44.9)
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income	369.7	306.3	367.8
Income Tax Expense (Benefit)	4.3	(78)	(44.9)
Pretax Income	374	228.3	322.9
Income Taxes on Pretax Income at Statutory Rate (21%)	$ 78.5	$ 47.9	$ 67.8
Federal Statutory Income Tax Rate	21.00%	21.00%	21.00%	35.00%
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation	$ 12.7	$ 10.8	$ 9.4
State and Local Income Taxes, Net	7.9	9	9.1
Removal Costs	(5.7)	(6.4)	(7.9)
AFUDC	(4.5)	(5.2)	(4.3)
Parent Company Loss Benefit	(6.2)	(4.1)	(3.6)
Tax Reform Excess ADIT Reversal	(72.3)	(130.4)	(108.5)
Federal Return to Provision	(7.2)	(1)	(6.6)
Other	1.1	1.4	(0.3)
Income Tax Expense (Benefit)	$ 4.3	$ (78)	$ (44.9)
Effective Income Tax Rate	1.10%	(34.20%)	(13.90%)
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets	$ 500.6	$ 486.2
Deferred Tax Liabilities	(2,250.5)	(2,167)
Property Related Temporary Differences	(1,412)	(1,420)
Amounts Due from Customers for Future Federal Income Taxes	198.3	222.8
Deferred State Income Taxes	(336.5)	(337.2)
Securitized Assets	(44.7)	(49.3)
Regulatory Assets	(114.8)	(71)
Operating Lease Liability	16.7	16.5
All Other, Net	(56.9)	(42.6)
Net Deferred Tax Liabilities	(1,749.9)	(1,680.8)
Income Taxes (Textuals) [Abstract]
Income Tax Expense (Benefit)	4.3	(78)	$ (44.9)
Proceeds from Income Tax Refunds	$ 7
Appalachian Power Co [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date	Dec. 31, 2036
Appalachian Power Co [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date	Dec. 31, 2040
Indiana Michigan Power Co [Member]
Federal:
Current	$ 11.3	48.1	60.9
Deferred	(20.6)	(57.1)	(48.8)
Total Federal	(9.3)	(9)	12.1
Current	1.9	(2.4)	15.8
Deferred	(0.1)	0.8	1.2
Total State and Local	1.8	(1.6)	17
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)	(7.5)	(10.6)	29.1
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income	284.8	269.4	261.3
Income Tax Expense (Benefit)	(7.5)	(10.6)	29.1
Pretax Income	277.3	258.8	290.4
Income Taxes on Pretax Income at Statutory Rate (21%)	$ 58.2	$ 54.3	$ 61
Federal Statutory Income Tax Rate	21.00%	21.00%	21.00%	35.00%
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation	$ 1.6	$ 4	$ 1.5
Investment Tax Credit Amortization	(4.5)	(3.6)	(4.7)
State and Local Income Taxes, Net	1.5	(1.2)	13.4
Removal Costs	(10.5)	(12.8)	(8)
AFUDC	(2.4)	(4.1)	(2.5)
Parent Company Loss Benefit	(6.4)	(3.3)	(2.3)
Tax Reform Excess ADIT Reversal	(46.8)	(42.5)	(25.8)
Federal Return to Provision	1.9	(0.3)	(4.6)
Other	(0.1)	(1.1)	1.1
Income Tax Expense (Benefit)	$ (7.5)	$ (10.6)	$ 29.1
Effective Income Tax Rate	(2.70%)	(4.10%)	10.00%
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets	$ 989.5	$ 970.5
Deferred Tax Liabilities	(2,053.9)	(1,950.2)
Property Related Temporary Differences	(409.2)	(430.7)
Amounts Due from Customers for Future Federal Income Taxes	147.9	169.6
Deferred State Income Taxes	(211.1)	(194.4)
Regulatory Assets	(16.5)	(26.9)
Accrued Nuclear Decommissioning	(626.4)	(557.4)
Operating Lease Liability	46.6	61.9
All Other, Net	4.3	(1.8)
Net Deferred Tax Liabilities	(1,064.4)	(979.7)
Income Taxes (Textuals) [Abstract]
Income Tax Expense (Benefit)	$ (7.5)	(10.6)	$ 29.1
Indiana Michigan Power Co [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date	Dec. 31, 2036
Indiana Michigan Power Co [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date	Dec. 31, 2040
Ohio Power Co [Member]
Federal:
Current	$ (26.6)	(10)	55.6
Deferred	74	40.6	(36.9)
Total Federal	47.4	30.6	18.7
Current	(5.4)	1.1	4.6
Deferred	3.2	3.2	0.7
Total State and Local	(2.2)	4.3	5.3
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)	45.2	34.9	24
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income	271.4	297.1	325.5
Income Tax Expense (Benefit)	45.2	34.9	24
Pretax Income	316.6	332	349.5
Income Taxes on Pretax Income at Statutory Rate (21%)	$ 66.5	$ 69.7	$ 73.4
Federal Statutory Income Tax Rate	21.00%	21.00%	21.00%	35.00%
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation	$ 3.7	$ (1.4)	$ 2.4
State and Local Income Taxes, Net	(1.7)	3.4	4.2
AFUDC	(2.6)	(3.8)	(2.1)
Parent Company Loss Benefit	0	(1.8)	(6)
Tax Reform Excess ADIT Reversal	(27.2)	(27.3)	(51)
Federal Return to Provision	6.5	(3.7)	0.2
Other	0	(0.2)	2.9
Income Tax Expense (Benefit)	$ 45.2	$ 34.9	$ 24
Effective Income Tax Rate	14.30%	10.50%	6.90%
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets	$ 210.8	$ 202.3
Deferred Tax Liabilities	(1,165.9)	(1,051.6)
Property Related Temporary Differences	(1,016)	(890.8)
Amounts Due from Customers for Future Federal Income Taxes	121.1	130.2
Deferred State Income Taxes	(40.7)	(35.5)
Regulatory Assets	(53.7)	(48)
Operating Lease Liability	19.4	18.3
All Other, Net	14.8	(23.5)
Net Deferred Tax Liabilities	(955.1)	(849.3)
Income Taxes (Textuals) [Abstract]
Income Tax Expense (Benefit)	45.2	34.9	$ 24
Proceeds from Income Tax Refunds	$ 9
Ohio Power Co [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date	Dec. 31, 2036
Ohio Power Co [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date	Dec. 31, 2040
Public Service Co Of Oklahoma [Member]
Federal:
Current	$ (11.4)	25.5	35.6
Deferred	8.3	(26)	(36.7)
Total Federal	(3.1)	(0.5)	(1.1)
Current	0.1	0.2	(0.2)
Deferred	8.2	7.8	6.3
Total State and Local	8.3	8	6.1
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)	5.2	7.5	5
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income	123	137.6	83.2
Income Tax Expense (Benefit)	5.2	7.5	5
Pretax Income	128.2	145.1	88.2
Income Taxes on Pretax Income at Statutory Rate (21%)	$ 26.9	$ 30.5	$ 18.5
Federal Statutory Income Tax Rate	21.00%	21.00%	21.00%	35.00%
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation	$ 1.1	$ 0.6	$ 0.7
Investment Tax Credit Amortization	(2.1)	(0.5)	(1.7)
State and Local Income Taxes, Net	6.5	6.3	4.8
Parent Company Loss Benefit	(0.2)	(2.1)	(1.4)
Tax Reform Excess ADIT Reversal	(25.5)	(24.5)	(15.5)
Other	(1.5)	(2.8)	(0.4)
Income Tax Expense (Benefit)	$ 5.2	$ 7.5	$ 5
Effective Income Tax Rate	4.10%	5.20%	5.70%
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets	$ 239.8	$ 257.4
Deferred Tax Liabilities	(928.3)	(885.7)
Property Related Temporary Differences	(661.8)	(627.6)
Amounts Due from Customers for Future Federal Income Taxes	118.5	127.2
Deferred State Income Taxes	(107.7)	(100.4)
Regulatory Assets	(39.1)	(44.6)
Net Operating Loss Carryforward	12.9	10.2
All Other, Net	(11.3)	6.9
Net Deferred Tax Liabilities	(688.5)	(628.3)
Income Taxes (Textuals) [Abstract]
Income Tax Expense (Benefit)	$ 5.2	7.5	$ 5
Public Service Co Of Oklahoma [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date	Dec. 31, 2036
Public Service Co Of Oklahoma [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date	Dec. 31, 2040
Southwestern Electric Power Co [Member]
Federal:
Current	$ (13.6)	6.9	18.3
Deferred	19.6	(10)	(1.9)
Total Federal	6	(3.1)	16.4
Current	(8.2)	0.8	2.3
Deferred	11.6	(2.4)	1.7
Total State and Local	3.4	(1.6)	4
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)	9.4	(4.7)	20.4
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income	183.7	162.2	152.2
Less: Equity Earnings – Dolet Hills	(2.9)	(3)	(2.7)
Income Tax Expense (Benefit)	9.4	(4.7)	20.4
Pretax Income	190.2	154.5	169.9
Income Taxes on Pretax Income at Statutory Rate (21%)	$ 39.9	$ 32.4	$ 35.7
Federal Statutory Income Tax Rate	21.00%	21.00%	21.00%	35.00%
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation	$ 1.9	$ 1.9	$ 1.9
Depletion	(3.4)	(3.4)	(3.4)
State and Local Income Taxes, Net	2.7	(1.3)	3.2
AFUDC	(1.5)	(1.4)	(1.3)
Parent Company Loss Benefit	(5.6)	(1.6)	(0.6)
Tax Reform Excess ADIT Reversal	(21.9)	(29.9)	(16)
Other	(2.7)	(1.4)	0.9
Income Tax Expense (Benefit)	$ 9.4	$ (4.7)	$ 20.4
Effective Income Tax Rate	4.90%	(3.00%)	12.00%
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets	$ 338.1	$ 359.6
Deferred Tax Liabilities	(1,355.7)	(1,300.5)
Property Related Temporary Differences	(985.1)	(947.6)
Amounts Due from Customers for Future Federal Income Taxes	162.7	169.8
Deferred State Income Taxes	(214.7)	(200.3)
Regulatory Assets	(26.2)	(30.2)
Net Operating Loss Carryforward	33.4	38.2
All Other, Net	12.3	29.2
Net Deferred Tax Liabilities	(1,017.6)	(940.9)
Income Taxes (Textuals) [Abstract]
Income Tax Expense (Benefit)	$ 9.4	(4.7)	$ 20.4
Southwestern Electric Power Co [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date	Dec. 31, 2036
Southwestern Electric Power Co [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date	Dec. 31, 2040
Arkansas
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	$ 87.2
Arkansas | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2021
Arkansas | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2028
Arkansas | Southwestern Electric Power Co [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	$ 86.4
Arkansas | Southwestern Electric Power Co [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2021
Arkansas | Southwestern Electric Power Co [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2024
Kentucky
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	$ 163.7
Kentucky | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2030
Kentucky | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2037
Louisiana
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	$ 466.8
Louisiana | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2025
Louisiana | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2040
Louisiana | Southwestern Electric Power Co [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	$ 454.3
Louisiana | Southwestern Electric Power Co [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2032
Louisiana | Southwestern Electric Power Co [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2037
Oklahoma
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	$ 569.4
Oklahoma | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2034
Oklahoma | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2037
Oklahoma | AEP Transmission Co [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	$ 195.4
Oklahoma | AEP Transmission Co [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2034
Oklahoma | AEP Transmission Co [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2037
Oklahoma | Public Service Co Of Oklahoma [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	$ 354.5
Oklahoma | Public Service Co Of Oklahoma [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2034
Oklahoma | Public Service Co Of Oklahoma [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2037
Tennessee
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	$ 31.1
Tennessee | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2028
Tennessee | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2035
Virginia
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	$ 29.4
Virginia | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2025
Virginia | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2037
West Virginia
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	$ 21.9
West Virginia | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2029
West Virginia | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2037
West Virginia | Indiana Michigan Power Co [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	$ 2.5
West Virginia | Indiana Michigan Power Co [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2032
West Virginia | Indiana Michigan Power Co [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2037
Ohio Municipal
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	$ 649.8
Ohio Municipal | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2021
Ohio Municipal | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2025
Ohio Municipal | AEP Transmission Co [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	$ 18.4
Ohio Municipal | AEP Transmission Co [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2023
Ohio Municipal | AEP Transmission Co [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2023
Indiana
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	$ 145.7
Indiana | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2039
Indiana | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2039
Colorado
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	$ 95.7
Pennsylvania
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	$ 56.5
Pennsylvania | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2030
Pennsylvania | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2040
New Jersey
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	$ 60.2
New Jersey | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2036
New Jersey | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2040
Illinois
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	$ 15.6
Illinois | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2031
Illinois | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2031
Michigan
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward	$ 14.9
Michigan | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2029
Michigan | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2029
Federal
Tax Credit Carryforward
Tax Credit Carryforward, Amount	$ 323.6
Federal | AEP Texas Inc. [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	1.2
Federal | AEP Transmission Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	0.1
Federal | Appalachian Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	1.6
Federal | Indiana Michigan Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	9.7
Federal | Ohio Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	0.5
Federal | Public Service Co Of Oklahoma [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	0.5
Federal | Southwestern Electric Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	1.3
State and Local Jurisdiction
Tax Credit Carryforward
Tax Credit Carryforward, Amount	38.4
Income Taxes (Textuals) [Abstract]
Valuation Allowance	9
State and Local Jurisdiction | AEP Texas Inc. [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	0
State and Local Jurisdiction | AEP Transmission Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	0
State and Local Jurisdiction | Appalachian Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	0
State and Local Jurisdiction | Indiana Michigan Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	0
State and Local Jurisdiction | Ohio Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	0
State and Local Jurisdiction | Public Service Co Of Oklahoma [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	38.4
State and Local Jurisdiction | Southwestern Electric Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount	0
Dolet Hills Lignite Co, LLC [Member]
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Less: Equity Earnings – Dolet Hills	(2.9)	(3)	(2.7)
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	$ (2.9)	$ (3)	$ (2.7)

Leases (Details)

Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Lease Rental Costs
Operating Lease, Cost	$ 279.6		$ 286		$ 245
Finance Lease Right-of-Use Asset Amortization	61.9		70.8		62.4
Interest Expense on Finance Leases	15.4		16.4		16.4
Total Lease Rental Costs	$ 356.9	[1]	$ 373.2	[1]	323.8
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases	5 years 3 months 18 days		5 years 2 months 23 days
Weighted Average Remaining Lease Term, Finance Leases	5 years 5 months 4 days		5 years 10 months 6 days
Weighted Average Discount Rate, Operating Leases	3.44%		3.60%
Weighted Average Discount Rate, Finance Leases	5.68%		5.98%
Operating Cash Flows Used for Operating Leases	$ 280.3		$ 284.7
Operating Cash Flows Used for Finance Leases	15.4		16.4
Financing Cash Flows Used for Finance Leases	61.7		70.7		65.1
Non-cash Acquisitions Under Operating Leases	161.7		125
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	23,133.9		22,762.4
Other Property, Plant and Equipment	5,294.6		4,811.5
Total Property, Plant and Equipment	84,313		79,145.7
Accumulated Amortization	20,411.4		19,007.6
Net Property, Plant and Equipment Under Finance Leases	284.2		303.1
Other Liabilities, Noncurrent	728		719.8
Finance Lease Liability Due Within One Year	1,199.3		1,373.8
Total Obligations Under Finance Leases	289.1		306.8
Operating Lease Asset and Related Obligations
Operating Lease Assets	866.4		957.4
Operating Lease Noncurrent Liability	638.4		734.6
Operating Lease Liability Due Within One Year	241.3		234.1
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	879.7		968.7
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Year 1	72.2		72.7
Year 2	64		64.9
Year 3	56.2		56.4
Year 4	63.5		49.6
Year 5	32.7		57.4
Finance Leases, Later Years	48.9		64.4
Finance Leases, Total Future Minimum Lease Payments	337.5		365.4
Imputed Interest on Finance Leases	48.4		58.6
Total Obligations Under Finance Leases	289.1		306.8
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Year 1	270.8		269.9
Year 2	263.3		253.6
Year 3	94.2		245.6
Year 4	81.6		74.8
Year 5	68		62
Operating Leases, Later Years	193		169.7
Operating Leases, Total Future Minimum Lease Payments	970.9		1,075.6
Imputed Interest on Operating Leases	91.2		106.9
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	879.7		968.7
Maximum Potential Loss
Max Potential Loss on Master Lease Agreements	50.3
Rockport Lease [Member]
Future Minimum Rentals, Sale Leaseback Transactions
2021	147.8
2022	147.6
Total Future Minimum Lease Payments	295.4
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	$ 48
Guarantor Obligations, Current Carrying Value	3
Guarantee Obligations Current Carrying Value Other Liabilities Current	1
Guarantee Obligations Current Carrying Value Other Liabilities Noncurrent	2
Finance Lease Assets [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	138.2		131.6
Other Property, Plant and Equipment	322.8		323
Total Property, Plant and Equipment	461		454.6
Accumulated Amortization	176.8		151.5
Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Other Liabilities, Noncurrent	231		249.2
Finance Lease Liability Due Within One Year	58.1		57.6
Operating Lease Assets [Member]
Operating Lease Asset and Related Obligations
Operating Lease Assets	866.4		957.4
AEP Texas Inc. [Member]
Lease Rental Costs
Operating Lease, Cost	17.4		16.5		13.6
Finance Lease Right-of-Use Asset Amortization	6.3		5.1		4.8
Interest Expense on Finance Leases	1.5		1.4		1.2
Total Lease Rental Costs	$ 25.2	[1]	$ 23	[1]	19.6
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases	6 years 6 months 3 days		6 years 11 months 4 days
Weighted Average Remaining Lease Term, Finance Leases	6 years 25 days		6 years 8 months 8 days
Weighted Average Discount Rate, Operating Leases	3.60%		3.77%
Weighted Average Discount Rate, Finance Leases	4.39%		4.62%
Operating Cash Flows Used for Operating Leases	$ 17.1		$ 15.3
Operating Cash Flows Used for Finance Leases	1.5		1.4
Financing Cash Flows Used for Finance Leases	6.3		5.1		4.7
Non-cash Acquisitions Under Operating Leases	15.8		13.8
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	0		351.7
Other Property, Plant and Equipment	868.4		805.9
Total Property, Plant and Equipment	11,342.9		10,603.2
Accumulated Amortization	1,529.3		1,758.1
Net Property, Plant and Equipment Under Finance Leases	33.1		34.1
Other Liabilities, Noncurrent	57.2		81.1
Finance Lease Liability Due Within One Year	88.5		123.3
Total Obligations Under Finance Leases	33.1		34.1
Operating Lease Asset and Related Obligations
Operating Lease Noncurrent Liability	71		71.1
Operating Lease Liability Due Within One Year	14.5		12
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	85.5		83.1
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Year 1	7.6		7.3
Year 2	6.9		6.7
Year 3	6.2		6
Year 4	5.4		5.4
Year 5	4		4.6
Finance Leases, Later Years	7.8		9.8
Finance Leases, Total Future Minimum Lease Payments	37.9		39.8
Imputed Interest on Finance Leases	4.8		5.7
Total Obligations Under Finance Leases	33.1		34.1
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Year 1	17.5		16
Year 2	16.4		15.3
Year 3	14.8		14.2
Year 4	13.3		13
Year 5	10.9		11.4
Operating Leases, Later Years	23.9		26
Operating Leases, Total Future Minimum Lease Payments	96.8		95.9
Imputed Interest on Operating Leases	11.3		12.8
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	85.5		83.1
Maximum Potential Loss
Max Potential Loss on Master Lease Agreements	11.7
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	49.7		45.9
Total Property, Plant and Equipment	49.7		45.9
Accumulated Amortization	16.6		11.8
AEP Texas Inc. [Member] | Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Other Liabilities, Noncurrent	26.8		28.2
Finance Lease Liability Due Within One Year	6.3		5.9
AEP Texas Inc. [Member] | Operating Lease Assets [Member]
Operating Lease Asset and Related Obligations
Operating Lease Assets	84.1		81.8
AEP Transmission Co [Member]
Lease Rental Costs
Operating Lease, Cost	2.6		2.5		2.7
Finance Lease Right-of-Use Asset Amortization	0		0.1		0.1
Interest Expense on Finance Leases	0		0		0
Total Lease Rental Costs	$ 2.6	[1]	$ 2.6	[1]	2.8
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases	2 years 3 days		2 years 3 months
Weighted Average Remaining Lease Term, Finance Leases	0 years		3 months
Weighted Average Discount Rate, Operating Leases	1.51%		3.14%
Weighted Average Discount Rate, Finance Leases	0.00%		9.33%
Operating Cash Flows Used for Operating Leases	$ 2.6		$ 2.4
Operating Cash Flows Used for Finance Leases	0		0
Financing Cash Flows Used for Finance Leases	0		0
Non-cash Acquisitions Under Operating Leases	1.8		0.6
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Other Property, Plant and Equipment	329.5		269.6
Total Property, Plant and Equipment	11,345.6		9,893.2
Accumulated Amortization	572.8		402.3
Net Property, Plant and Equipment Under Finance Leases	0		0
Other Liabilities, Noncurrent	8		0.3
Finance Lease Liability Due Within One Year	9.9		14.6
Total Obligations Under Finance Leases	0		0
Operating Lease Asset and Related Obligations
Operating Lease Noncurrent Liability	0.4		1.9
Operating Lease Liability Due Within One Year	1.2		2.1
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	1.6		4
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Year 1	0		0
Year 2	0		0
Year 3	0		0
Year 4	0		0
Year 5	0		0
Finance Leases, Later Years	0		0
Finance Leases, Total Future Minimum Lease Payments	0		0
Imputed Interest on Finance Leases	0		0
Total Obligations Under Finance Leases	0		0
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Year 1	1.2		2.2
Year 2	0.2		1.2
Year 3	0.1		0.6
Year 4	0.1		0.1
Year 5	0		0
Operating Leases, Later Years	0		0
Operating Leases, Total Future Minimum Lease Payments	1.6		4.1
Imputed Interest on Operating Leases	0		0.1
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	1.6		4
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		0.2
Total Property, Plant and Equipment	0		0.2
Accumulated Amortization	0		0.2
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
AEP Transmission Co [Member] | Operating Lease Assets [Member]
Operating Lease Asset and Related Obligations
Operating Lease Assets	1.6		3.8
Appalachian Power Co [Member]
Lease Rental Costs
Operating Lease, Cost	19.1		19.5		18.2
Finance Lease Right-of-Use Asset Amortization	7.4		6.7		7
Interest Expense on Finance Leases	2.7		2.9		3
Total Lease Rental Costs	$ 29.2	[1]	$ 29.1	[1]	28.2
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases	6 years 3 months 7 days		6 years 3 months 10 days
Weighted Average Remaining Lease Term, Finance Leases	5 years 9 months		6 years 1 month 13 days
Weighted Average Discount Rate, Operating Leases	3.48%		3.64%
Weighted Average Discount Rate, Finance Leases	7.33%		8.08%
Operating Cash Flows Used for Operating Leases	$ 19.2		$ 19
Operating Cash Flows Used for Finance Leases	2.7		2.9
Financing Cash Flows Used for Finance Leases	7.4		6.7		6.9
Non-cash Acquisitions Under Operating Leases	16.2		10.2
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	6,633.7		6,563.7
Other Property, Plant and Equipment	627.2		571.3
Total Property, Plant and Equipment	16,110.3		15,514.2
Accumulated Amortization	4,716.2		4,432.3
Net Property, Plant and Equipment Under Finance Leases	41.7		41.8
Other Liabilities, Noncurrent	49.6		55.2
Finance Lease Liability Due Within One Year	164.5		170.9
Total Obligations Under Finance Leases	41.7		41.8
Operating Lease Asset and Related Obligations
Operating Lease Assets	78.8		78.5
Operating Lease Noncurrent Liability	64.4		64
Operating Lease Liability Due Within One Year	14.9		15.2
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	79.3		79.2
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Year 1	9.9		9.6
Year 2	9.4		8.9
Year 3	8.7		8.2
Year 4	8.1		7.7
Year 5	7		7.1
Finance Leases, Later Years	6.4		9.8
Finance Leases, Total Future Minimum Lease Payments	49.5		51.3
Imputed Interest on Finance Leases	7.8		9.5
Total Obligations Under Finance Leases	41.7		41.8
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Year 1	17.7		18.3
Year 2	17		15.7
Year 3	14.2		14.7
Year 4	11.3		11.9
Year 5	8.5		9
Operating Leases, Later Years	20		20
Operating Leases, Total Future Minimum Lease Payments	88.7		89.6
Imputed Interest on Operating Leases	9.4		10.4
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	79.3		79.2
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	42.8		39.9
Other Property, Plant and Equipment	20.3		18.9
Total Property, Plant and Equipment	63.1		58.8
Accumulated Amortization	21.4		17
Appalachian Power Co [Member] | Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Other Liabilities, Noncurrent	34.4		35
Finance Lease Liability Due Within One Year	7.3		6.8
Appalachian Power Co [Member] | Operating Lease Assets [Member]
Operating Lease Asset and Related Obligations
Operating Lease Assets	78.8		78.5
Indiana Michigan Power Co [Member]
Lease Rental Costs
Operating Lease, Cost	101.5		93.1		89.2
Finance Lease Right-of-Use Asset Amortization	6.5		5.7		6.6
Interest Expense on Finance Leases	3.1		2.9		3.3
Total Lease Rental Costs	$ 111.1	[1]	$ 101.7	[1]	99.1
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases	3 years 6 months		3 years 10 months 28 days
Weighted Average Remaining Lease Term, Finance Leases	5 years 9 months 14 days		6 years 6 months 18 days
Weighted Average Discount Rate, Operating Leases	3.42%		3.45%
Weighted Average Discount Rate, Finance Leases	8.29%		8.47%
Operating Cash Flows Used for Operating Leases	$ 102.2		$ 94.3
Operating Cash Flows Used for Finance Leases	3.1		3.1
Financing Cash Flows Used for Finance Leases	6.5		5.7		8.8
Non-cash Acquisitions Under Operating Leases	18.1		18.7
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	5,264.7		5,099.7
Other Property, Plant and Equipment	686.7		632.6
Total Property, Plant and Equipment	10,604.8		10,194
Accumulated Amortization	3,552.5		3,294.3
Net Property, Plant and Equipment Under Finance Leases	41.7		45.1
Other Liabilities, Noncurrent	69.2		67.8
Finance Lease Liability Due Within One Year	112		110.1
Total Obligations Under Finance Leases	41.7		45.1
Operating Lease Asset and Related Obligations
Operating Lease Assets	218.1		294.9
Operating Lease Noncurrent Liability	135.9		211.6
Operating Lease Liability Due Within One Year	85.6		87.3
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	221.5		298.9
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Year 1	9.3		9.4
Year 2	8.6		8.7
Year 3	7.9		8
Year 4	11.1		7.5
Year 5	5.5		10.8
Finance Leases, Later Years	12.2		16.4
Finance Leases, Total Future Minimum Lease Payments	54.6		60.8
Imputed Interest on Finance Leases	12.9		15.7
Total Obligations Under Finance Leases	41.7		45.1
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Year 1	92.5		97
Year 2	92.5		92.9
Year 3	11.4		92.8
Year 4	10		10.1
Year 5	8.9		8.6
Operating Leases, Later Years	21.8		21
Operating Leases, Total Future Minimum Lease Payments	237.1		322.4
Imputed Interest on Operating Leases	15.6		23.5
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	221.5		298.9
Maximum Potential Loss
Max Potential Loss on Master Lease Agreements	4.4
Indiana Michigan Power Co [Member] | Rockport Lease [Member]
Future Minimum Rentals, Sale Leaseback Transactions
2021	73.9
2022	73.8
Total Future Minimum Lease Payments	147.7
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		28.8
Other Property, Plant and Equipment	40.2		39.3
Total Property, Plant and Equipment	69		68.1
Accumulated Amortization	27.3		23
Indiana Michigan Power Co [Member] | Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Other Liabilities, Noncurrent	35.3		38.8
Finance Lease Liability Due Within One Year	6.4		6.3
Indiana Michigan Power Co [Member] | Operating Lease Assets [Member]
Operating Lease Asset and Related Obligations
Operating Lease Assets	218.1		294.9
Ohio Power Co [Member]
Lease Rental Costs
Operating Lease, Cost	17.1		18		10.7
Finance Lease Right-of-Use Asset Amortization	4.7		3.5		3.9
Interest Expense on Finance Leases	0.9		0.7		0.5
Total Lease Rental Costs	$ 22.7	[1]	$ 22.2	[1]	15.1
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases	7 years 5 months 8 days		7 years 11 months 8 days
Weighted Average Remaining Lease Term, Finance Leases	5 years 10 months 24 days		6 years 5 months 26 days
Weighted Average Discount Rate, Operating Leases	3.60%		3.76%
Weighted Average Discount Rate, Finance Leases	4.25%		4.54%
Operating Cash Flows Used for Operating Leases	$ 16.9		$ 18
Operating Cash Flows Used for Finance Leases	0.9		0.7
Financing Cash Flows Used for Finance Leases	4.7		3.5		3.8
Non-cash Acquisitions Under Operating Leases	18.1		35.4
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Other Property, Plant and Equipment	899.6		765.8
Total Property, Plant and Equipment	9,802.1		9,170
Accumulated Amortization	2,350		2,263
Net Property, Plant and Equipment Under Finance Leases	21.6		20.1
Other Liabilities, Noncurrent	40		42.7
Finance Lease Liability Due Within One Year	139.6		151.2
Total Obligations Under Finance Leases	21.6		20.1
Operating Lease Asset and Related Obligations
Operating Lease Noncurrent Liability	79.5		76
Operating Lease Liability Due Within One Year	13.1		12.5
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	92.6		88.5
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Year 1	5.5		4.7
Year 2	4.6		4.3
Year 3	3.9		3.4
Year 4	3.3		2.8
Year 5	2.2		2.4
Finance Leases, Later Years	4.9		5.7
Finance Leases, Total Future Minimum Lease Payments	24.4		23.3
Imputed Interest on Finance Leases	2.8		3.2
Total Obligations Under Finance Leases	21.6		20.1
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Year 1	16.6		16.2
Year 2	16		14.2
Year 3	14.9		13.5
Year 4	13.2		12.3
Year 5	11.5		10.7
Operating Leases, Later Years	34		36.5
Operating Leases, Total Future Minimum Lease Payments	106.2		103.4
Imputed Interest on Operating Leases	13.6		14.9
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	92.6		88.5
Maximum Potential Loss
Max Potential Loss on Master Lease Agreements	8.1
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	31.4		27.3
Total Property, Plant and Equipment	31.4		27.3
Accumulated Amortization	9.8		7.2
Ohio Power Co [Member] | Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Other Liabilities, Noncurrent	16.9		16.2
Finance Lease Liability Due Within One Year	4.7		3.9
Ohio Power Co [Member] | Operating Lease Assets [Member]
Operating Lease Asset and Related Obligations
Operating Lease Assets	92		88
Public Service Co Of Oklahoma [Member]
Lease Rental Costs
Operating Lease, Cost	7.8		6.8		5.7
Finance Lease Right-of-Use Asset Amortization	3.5		3.1		3.2
Interest Expense on Finance Leases	0.7		0.6		0.4
Total Lease Rental Costs	$ 12	[1]	$ 10.5	[1]	9.3
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases	7 years 10 days		7 years 25 days
Weighted Average Remaining Lease Term, Finance Leases	6 years 1 month 28 days		6 years 2 months 23 days
Weighted Average Discount Rate, Operating Leases	3.39%		3.64%
Weighted Average Discount Rate, Finance Leases	4.35%		4.62%
Operating Cash Flows Used for Operating Leases	$ 7.7		$ 6.7
Operating Cash Flows Used for Finance Leases	0.7		0.6
Financing Cash Flows Used for Finance Leases	3.5		3.1		3.3
Non-cash Acquisitions Under Operating Leases	12.3		8.2
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	1,480.7		1,574.6
Other Property, Plant and Equipment	393.3		342.1
Total Property, Plant and Equipment	5,925.6		5,683.4
Accumulated Amortization	1,605.6		1,580.1
Net Property, Plant and Equipment Under Finance Leases	15		15.1
Other Liabilities, Noncurrent	20.6		18.4
Finance Lease Liability Due Within One Year	84.2		87.5
Total Obligations Under Finance Leases	15		15.1
Operating Lease Asset and Related Obligations
Operating Lease Assets	42.6		36.8
Operating Lease Noncurrent Liability	36.2		31
Operating Lease Liability Due Within One Year	6.5		5.8
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	42.7		36.8
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Year 1	3.6		3.8
Year 2	3.1		3.2
Year 3	2.7		2.6
Year 4	2.3		2.3
Year 5	1.6		1.8
Finance Leases, Later Years	3.8		3.8
Finance Leases, Total Future Minimum Lease Payments	17.1		17.5
Imputed Interest on Finance Leases	2.1		2.4
Total Obligations Under Finance Leases	15		15.1
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Year 1	7.9		7.3
Year 2	7.6		6.4
Year 3	7.3		6
Year 4	6.5		5.6
Year 5	5.4		4.8
Operating Leases, Later Years	13.3		12
Operating Leases, Total Future Minimum Lease Payments	48		42.1
Imputed Interest on Operating Leases	5.3		5.3
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	42.7		36.8
Maximum Potential Loss
Max Potential Loss on Master Lease Agreements	4.8
Public Service Co Of Oklahoma [Member] | Finance Lease Assets [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	0.7		0.6
Other Property, Plant and Equipment	23		21.6
Total Property, Plant and Equipment	23.7		22.2
Accumulated Amortization	8.7		7.1
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		11.9
Finance Lease Liability Due Within One Year	3.1		3.2
Public Service Co Of Oklahoma [Member] | Operating Lease Assets [Member]
Operating Lease Asset and Related Obligations
Operating Lease Assets	42.6		36.8
Southwestern Electric Power Co [Member]
Lease Rental Costs
Operating Lease, Cost	9.4		8		6.5
Finance Lease Right-of-Use Asset Amortization	10.9		11		11.2
Interest Expense on Finance Leases	2.2		2.9		3.2
Total Lease Rental Costs	$ 22.5	[1]	$ 21.9	[1]	20.9
Supplemental Information Related to Leases
Weighted-Average Remaining Lease Term, Operating Leases	7 years 6 months 14 days		6 years 7 months 20 days
Weighted Average Remaining Lease Term, Finance Leases	4 years 11 months 12 days		5 years 1 month 28 days
Weighted Average Discount Rate, Operating Leases	3.45%		3.76%
Weighted Average Discount Rate, Finance Leases	4.77%		5.01%
Operating Cash Flows Used for Operating Leases	$ 9.4		$ 7.9
Operating Cash Flows Used for Finance Leases	2.2		3
Financing Cash Flows Used for Finance Leases	10.9		11		$ 11.5
Non-cash Acquisitions Under Operating Leases	18.4		11.4
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	4,681.4		4,691.4
Other Property, Plant and Equipment	788.8		733.4
Total Property, Plant and Equipment	10,246.7		9,968.9
Accumulated Amortization	3,158.5		2,873.7
Net Property, Plant and Equipment Under Finance Leases	53.6		57.3
Other Liabilities, Noncurrent	94.2		86.2
Finance Lease Liability Due Within One Year	173.4		133.9
Total Obligations Under Finance Leases	55.3		57.6
Operating Lease Asset and Related Obligations
Operating Lease Noncurrent Liability	44.1		34.7
Operating Lease Liability Due Within One Year	7.9		6.5
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	52		41.2
Finance Lease Liabilities Rolling Future Minimum Lease Payments
Year 1	13.1		12.9
Year 2	11.8		11.9
Year 3	10.9		10.6
Year 4	15.3		9.8
Year 5	5.7		14.2
Finance Leases, Later Years	5.8		6.8
Finance Leases, Total Future Minimum Lease Payments	62.6		66.2
Imputed Interest on Finance Leases	7.3		8.6
Total Obligations Under Finance Leases	55.3		57.6
Operating Lease Liabilities Rolling Future Minimum Lease Payments
Year 1	10.1		8.6
Year 2	9.6		8.2
Year 3	8.4		7.6
Year 4	6.9		6.4
Year 5	5.8		5
Operating Leases, Later Years	17.4		11.8
Operating Leases, Total Future Minimum Lease Payments	58.2		47.6
Imputed Interest on Operating Leases	6.2		6.4
Estimated Present Value of Future Minimum Lease Payments on Operating Leases	52		41.2
Maximum Potential Loss
Max Potential Loss on Master Lease Agreements	5.4
Southwestern Electric Power Co [Member] | Finance Lease Assets [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Generation	37.7		34.1
Other Property, Plant and Equipment	52.4		51.6
Total Property, Plant and Equipment	90.1		85.7
Accumulated Amortization	36.5		28.4
Southwestern Electric Power Co [Member] | Finance Lease Liabilities [Member]
Property, Plant and Equipment and Other Related Obligations Under Finance Leases
Other Liabilities, Noncurrent	44.6		47.1
Finance Lease Liability Due Within One Year	10.7		10.5
Southwestern Electric Power Co [Member] | Operating Lease Assets [Member]
Operating Lease Asset and Related Obligations
Operating Lease Assets	$ 48.5		$ 40.5
[1]	Excludes variable and short-term lease costs, which were immaterial for the twelve months ended December 31, 2020 and December 31, 2019.

Financing Activities (Details)

Financing Activities (Details) - USD ($)		1 Months Ended		12 Months Ended
		Feb. 25, 2021	Jan. 31, 2021	Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Shares of Company
Beginning Balance, Shares			516,808,354	514,373,631		513,450,036		512,210,644
Issued				2,434,723		923,595		1,239,392
Ending Balance, Shares				516,808,354		514,373,631		513,450,036
Treasury Stock, Shares, Beginning Balance			20,204,160	20,204,160		20,204,160		20,205,046
Partners' Capital Account, Units, Treasury Units Reissued	[1]							(886)
Treasury Stock, Shares, Ending Balance				20,204,160		20,204,160		20,204,160
Long-term Debt
Senior Unsecured Notes				$ 25,116,100,000		$ 21,180,700,000
Pollution Control Bonds	[2]			1,936,700,000		1,998,800,000
Notes Payable	[3]			239,100,000		234,300,000
Securitization Bonds				716,400,000		1,025,100,000
Spent Nuclear Fuel Obligation	[4]			281,200,000		279,800,000
Junior Subordinated Notes	[5]			1,624,100,000		787,800,000
Other Long-term Debt				1,158,900,000		1,219,000,000
Total Long-term Debt Outstanding				31,072,500,000		26,725,500,000
Outstanding Long-term Debt
Principal Amount, 2021				2,086,100,000
Principal Amount, 2022	[6]			3,538,400,000
Principal Amount, 2023	[7]			2,659,300,000
Principal Amount, 2024				723,400,000
Principal Amount, 2025				1,726,300,000
Principal Amount, After 2025				20,599,200,000
Principal Amount, Total				31,332,700,000
Unamortized Discount, Net and Debt Issuance Costs				(260,200,000)
Total Long-term Debt Outstanding				31,072,500,000		26,725,500,000
Short-term Debt
Securitized Debt for Receivables	[8]			592,000,000		710,000,000
Commercial Paper				1,852,300,000		2,110,000,000
Notes Payable				35,000,000		18,300,000
Total Short-term Debt				$ 2,479,300,000		$ 2,838,300,000
Securitized Debt for Receivables	[8],[9]			0.85%		2.42%
Comparative Accounts Receivable Information
Effective Interest Rates on Securitization of Accounts Receivable				0.85%		2.42%		2.16%
Net Uncollectible Accounts Receivable Written Off				$ 15,300,000		$ 26,600,000		$ 27,600,000
Customer Accounts Receivable Managed Portfolio
Accounts Receivable Retained Interest and Pledged as Collateral Less Uncollectible Accounts				958,400,000		841,800,000
Total Principal Outstanding				592,000,000		710,000,000
Delinquent Securitized Accounts Receivable				62,300,000		39,600,000
Bad Debt Reserves Related to Securitized Sale of Accounts Receivable				60,000,000		32,100,000
Unbilled Receivables Related to Securitization, Sale of Accounts Receivable				296,800,000		266,800,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				14,918,500,000		15,561,400,000		16,195,700,000
Financing Activities (Textuals)
Repayments of Long-term Debt				1,339,800,000		1,220,800,000		2,782,000,000
Proceeds from Issuance of Long-term Debt				5,626,100,000		4,536,600,000		4,945,700,000
Forward Equity Purchase Contract included in Current and Noncurrent liabilities				$ (86,200,000)		(7,600,000)		23,100,000
Maximum Percentage Debt to Capitalization				67.50%
Restricted Net Assets				$ 14,000,000,000
Dividend Restrictions	[10]			2,369,500,000
Retained Earnings Available to Pay Dividends				7,100,000,000
Dividends Paid on Common Stock				(1,424,900,000)		$ (1,350,000,000)		(1,255,500,000)
Credit Facilities, Total				$ 4,000,000,000
Weighted Average Interest Rate of Commercial Paper Outstanding During Year				1.28%
Maximum Amount of Commercial Paper Outstanding				$ 3,000,000,000
Total Commitment From Bank Conduits To Finance Receivables				750,000,000
Maximum Value of Shares to be Issued Under ATM Program				$ 1,000,000,000
Maximum Percentage Paid to Selling Agents				2.00%
2019 Equity Units [Member]
Financing Activities (Textuals)
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				2022
Equity Units Annual Distribution Rate				6.125%
Forward Equity Contract Payment Rate				2.725%
Maximum Shares Issued Under Equity Units Conversion				9,701,860
Corporate unit ownership share of an equity unit				5.00%
2020 Equity Units [Member]
Financing Activities (Textuals)
Equity Units Issued				17,000,000
Per Unit Conversion for Equity Units				$ 50
Net Equity Units Issuance Proceeds				833,000,000
Principal Amounts of Junior Subordinated Debt				$ 1,000
Forward Equity Purchase Contract Date				2023
Equity Units Annual Distribution Rate				6.125%
Forward Equity Contract Payment Rate				4.825%
Maximum Shares Issued Under Equity Units Conversion				10,205,100
Corporate unit ownership share of an equity unit				5.00%
Minimum [Member] | 2019 Equity Units [Member]
Financing Activities (Textuals)
AEP Share Price for Equity Unit Conversion				$ 82.98
Shares Per Equity Unit				0.5021
Minimum [Member] | 2020 Equity Units [Member]
Financing Activities (Textuals)
AEP Share Price for Equity Unit Conversion				$ 83.29
Shares Per Equity Unit				0.5003
Maximum [Member] | 2019 Equity Units [Member]
Financing Activities (Textuals)
AEP Share Price for Equity Unit Conversion				$ 99.58
Shares Per Equity Unit				0.6026
Maximum [Member] | 2020 Equity Units [Member]
Financing Activities (Textuals)
AEP Share Price for Equity Unit Conversion				$ 99.95
Shares Per Equity Unit				0.6003
Commercial Paper [Member]
Short-term Debt
Debt, Weighted Average Interest Rate	[9]			0.29%		2.10%
Loans Payable [Member]
Short-term Debt
Debt, Weighted Average Interest Rate	[9]			2.55%		3.29%
AEP Texas Inc. [Member]
Long-term Debt
Senior Unsecured Notes				$ 3,687,600,000		$ 3,090,900,000
Pollution Control Bonds				439,700,000		490,300,000
Securitization Bonds				492,600,000		776,800,000
Other Long-term Debt				200,500,000		200,400,000
Total Long-term Debt Outstanding				4,820,400,000		4,558,400,000
Outstanding Long-term Debt
Principal Amount, 2021				88,700,000
Principal Amount, 2022				716,000,000
Principal Amount, 2023				278,500,000
Principal Amount, 2024				96,000,000
Principal Amount, 2025				324,500,000
Principal Amount, After 2025				3,357,000,000
Principal Amount, Total				4,860,700,000
Unamortized Discount, Net and Debt Issuance Costs				(40,300,000)
Total Long-term Debt Outstanding				4,820,400,000		4,558,400,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				1,528,000,000		1,551,600,000		1,493,000,000
Financing Activities (Textuals)
Repayments of Long-term Debt				392,100,000		401,800,000		266,100,000
Proceeds from Issuance of Long-term Debt				$ 652,700,000		1,070,400,000		$ 494,000,000
Maximum Percentage Debt to Capitalization				67.50%
Dividend Restrictions				$ 694,000,000
AEP Texas Inc. [Member] | Utility [Member]
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				320,400,000		390,700,000
Maximum Loans to Money Pool				313,400,000		213,100,000
Average Borrowings from Money Pool				132,000,000		239,300,000
Average Loans to Money Pool				139,000,000		194,400,000
Net Loans (Borrowings) to/from Money Pool				(67,100,000)		199,700,000
Authorized Short Term Borrowing Limit				$ 500,000,000		$ 500,000,000
Maximum and Minimum Interest Rates
Maximum Interest Rate				2.70%		3.43%		2.97%
Minimum Interest Rate				0.27%		1.77%		1.81%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				1.51%		2.63%		2.26%
Average Interest Rate For Funds Loaned				0.81%		2.03%		2.29%
AEP Texas Inc. [Member] | Nonutility [Member]
Maximum Interest Rate For Funds Loaned				2.70%		3.02%		2.97%
Minimum Interest Rate for Funds Loaned				0.27%		1.91%		1.83%
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Loans to Money Pool				$ 7,500,000		$ 8,000,000
Average Loans to Money Pool				7,100,000		7,700,000
Net Loans (Borrowings) to/from Money Pool				$ 7,100,000		$ 7,500,000
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Loaned				1.18%		2.56%		2.36%
AEP Transmission Co [Member]
Long-term Debt
Senior Unsecured Notes				$ 3,948,500,000		$ 3,427,300,000
Total Long-term Debt Outstanding				3,948,500,000		3,427,300,000
Outstanding Long-term Debt
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, 2025				90,000,000
Principal Amount, After 2025				3,591,000,000
Principal Amount, Total				3,990,000,000
Unamortized Discount, Net and Debt Issuance Costs				(41,500,000)
Total Long-term Debt Outstanding				3,948,500,000		3,427,300,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				1,232,700,000		1,042,100,000		$ 832,000,000
Financing Activities (Textuals)
Repayments of Long-term Debt				0		85,000,000		50,000,000
Proceeds from Issuance of Long-term Debt				519,500,000		688,000,000		$ 321,000,000
Sub-Limit of Secured Debt				$ 50,000,000
Maximum Percentage of Consolidated Tangible Net Assets				10.00%
Tangible Capital to Tangible Assets				0.016
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				358,400,000		374,900,000
Maximum Loans to Money Pool				259,700,000		244,400,000
Average Borrowings from Money Pool				116,300,000		152,000,000
Average Loans to Money Pool				55,000,000		52,800,000
Net Loans (Borrowings) to/from Money Pool				(155,400,000)		(119,000,000)
Authorized Short Term Borrowing Limit	[11]			$ 820,000,000		$ 795,000,000
Maximum and Minimum Interest Rates
Maximum Interest Rate				2.70%		3.43%		2.97%
Minimum Interest Rate				0.27%		1.77%		1.81%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				1.29%		2.64%		2.27%
Average Interest Rate For Funds Loaned				1.99%		2.41%		2.10%
AEP Transmission Co [Member] | Direct Borrowing [Member]
Maximum Interest Rate for Funds Borrowed				2.70%		3.02%		2.97%
Minimum Interest Rate For Funds Borrowed				0.27%		1.91%		1.76%
Maximum Interest Rate For Funds Loaned				2.70%		3.02%		2.97%
Minimum Interest Rate for Funds Loaned				0.27%		1.91%		1.76%
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				$ 1,400,000		$ 1,300,000
Maximum Loans to Money Pool				215,300,000		153,500,000
Average Borrowings from Money Pool				1,300,000		1,300,000
Average Loans to Money Pool				132,600,000		68,000,000
Borrowings from Parent				1,200,000		1,300,000
Loans to Parent				109,000,000		68,700,000
Authorized Short Term Borrowing Limit	[12]			$ 50,000,000		$ 75,000,000
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				1.20%		2.55%		2.36%
Average Interest Rate For Funds Loaned				1.13%		2.51%		2.36%
Appalachian Power Co [Member]
Long-term Debt
Senior Unsecured Notes				$ 3,937,200,000		$ 3,442,700,000
Pollution Control Bonds	[2]			546,300,000		546,100,000
Securitization Bonds				223,800,000		248,300,000
Other Long-term Debt				126,800,000		126,700,000
Total Long-term Debt Outstanding				4,834,100,000		4,363,800,000
Outstanding Long-term Debt
Principal Amount, 2021				518,300,000
Principal Amount, 2022				355,400,000
Principal Amount, 2023				26,600,000
Principal Amount, 2024				113,500,000
Principal Amount, 2025				443,900,000
Principal Amount, After 2025				3,418,300,000
Principal Amount, Total				4,876,000,000
Unamortized Discount, Net and Debt Issuance Costs				(41,900,000)
Total Long-term Debt Outstanding				4,834,100,000		4,363,800,000
Accounts Receivable and Accrued Unbilled Revenue
Accounts Receivable and Accrued Unbilled Revenues				136,000,000		120,900,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				2,809,200,000		2,911,100,000		$ 2,993,200,000
Proceeds on Sale of Receivables to AEP Credit
Proceeds from Sale of Receivables to AEP Credit				1,272,900,000		1,310,300,000		1,421,000,000
Financing Activities (Textuals)
Repayments of Long-term Debt				140,300,000		180,500,000		124,000,000
Proceeds from Issuance of Long-term Debt				$ 606,900,000		478,200,000		$ 203,200,000
Maximum Percentage Debt to Capitalization				67.50%
Dividend Restrictions				$ 175,100,000
Appalachian Power Co [Member] | Utility [Member]
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				434,300,000		270,000,000
Maximum Loans to Money Pool				189,000,000		232,200,000
Average Borrowings from Money Pool				242,800,000		115,900,000
Average Loans to Money Pool				76,300,000		51,900,000
Net Loans (Borrowings) to/from Money Pool				2,800,000		(214,600,000)
Authorized Short Term Borrowing Limit				$ 500,000,000		$ 500,000,000
Maximum and Minimum Interest Rates
Maximum Interest Rate				2.70%		3.43%		2.97%
Minimum Interest Rate				0.27%		1.77%		1.81%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				2.12%		2.45%		2.26%
Average Interest Rate For Funds Loaned				0.85%		2.66%		2.21%
Indiana Michigan Power Co [Member]
Long-term Debt
Senior Unsecured Notes				$ 2,152,200,000		$ 2,150,700,000
Pollution Control Bonds	[2]			240,500,000		240,000,000
Notes Payable	[3]			146,700,000		168,700,000
Spent Nuclear Fuel Obligation	[4]			281,200,000		279,800,000
Other Long-term Debt				209,300,000		211,000,000
Total Long-term Debt Outstanding				3,029,900,000		3,050,200,000
Outstanding Long-term Debt
Principal Amount, 2021				369,600,000
Principal Amount, 2022				45,100,000
Principal Amount, 2023				273,900,000
Principal Amount, 2024				8,100,000
Principal Amount, 2025				151,500,000
Principal Amount, After 2025				2,206,200,000
Principal Amount, Total				3,054,400,000
Unamortized Discount, Net and Debt Issuance Costs				(24,500,000)
Total Long-term Debt Outstanding				3,029,900,000		3,050,200,000
Accounts Receivable and Accrued Unbilled Revenue
Accounts Receivable and Accrued Unbilled Revenues				170,500,000		141,800,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				2,236,000,000		2,308,100,000		$ 2,381,000,000
Proceeds on Sale of Receivables to AEP Credit
Proceeds from Sale of Receivables to AEP Credit				1,891,800,000		1,824,200,000		1,843,000,000
Financing Activities (Textuals)
Repayments of Long-term Debt				93,200,000		117,100,000		884,900,000
Proceeds from Issuance of Long-term Debt				$ 69,500,000		123,300,000		$ 1,168,100,000
Maximum Percentage Debt to Capitalization				67.50%
Dividend Restrictions				$ 519,700,000
Indiana Michigan Power Co [Member] | Utility [Member]
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				218,600,000		158,800,000
Maximum Loans to Money Pool				13,400,000		66,000,000
Average Borrowings from Money Pool				114,500,000		71,500,000
Average Loans to Money Pool				13,300,000		16,200,000
Net Loans (Borrowings) to/from Money Pool				(89,700,000)		(101,200,000)
Authorized Short Term Borrowing Limit				$ 500,000,000		$ 500,000,000
Maximum and Minimum Interest Rates
Maximum Interest Rate				2.70%		3.43%		2.97%
Minimum Interest Rate				0.27%		1.77%		1.81%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				1.07%		2.34%		2.16%
Average Interest Rate For Funds Loaned				1.18%		2.60%		2.08%
Ohio Power Co [Member]
Long-term Debt
Senior Unsecured Notes				$ 2,429,400,000		$ 2,081,000,000
Other Long-term Debt				800,000		1,000,000
Total Long-term Debt Outstanding				2,430,200,000		2,082,000,000
Outstanding Long-term Debt
Principal Amount, 2021				500,100,000
Principal Amount, 2022				100,000
Principal Amount, 2023				100,000
Principal Amount, 2024				100,000
Principal Amount, 2025				100,000
Principal Amount, After 2025				1,950,300,000
Principal Amount, Total				2,450,800,000
Unamortized Discount, Net and Debt Issuance Costs				(20,600,000)
Total Long-term Debt Outstanding				2,430,200,000		2,082,000,000
Accounts Receivable and Accrued Unbilled Revenue
Accounts Receivable and Accrued Unbilled Revenues				398,800,000		330,300,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				2,665,000,000		2,748,800,000		$ 3,079,900,000
Proceeds on Sale of Receivables to AEP Credit
Proceeds from Sale of Receivables to AEP Credit				2,366,200,000		2,293,600,000		2,674,500,000
Financing Activities (Textuals)
Repayments of Long-term Debt				100,000		80,300,000		397,100,000
Proceeds from Issuance of Long-term Debt				347,000,000		444,300,000		$ 392,800,000
Dividend Restrictions				0
Ohio Power Co [Member] | Utility [Member]
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				353,900,000		291,200,000
Maximum Loans to Money Pool				32,800,000		178,600,000
Average Borrowings from Money Pool				182,400,000		129,200,000
Average Loans to Money Pool				25,200,000		50,100,000
Net Loans (Borrowings) to/from Money Pool				(259,200,000)		(131,000,000)
Authorized Short Term Borrowing Limit				$ 500,000,000		$ 500,000,000
Maximum and Minimum Interest Rates
Maximum Interest Rate				2.70%		3.43%		2.97%
Minimum Interest Rate				0.27%		1.77%		1.81%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				0.99%		2.67%		2.18%
Average Interest Rate For Funds Loaned				2.06%		2.68%		2.47%
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				$ 1,246,300,000		$ 1,245,600,000
Pollution Control Bonds				0		12,700,000
Other Long-term Debt				127,500,000		127,900,000
Total Long-term Debt Outstanding				1,373,800,000		1,386,200,000
Outstanding Long-term Debt
Principal Amount, 2021				500,000
Principal Amount, 2022				375,500,000
Principal Amount, 2023				500,000
Principal Amount, 2024				600,000
Principal Amount, 2025				125,600,000
Principal Amount, After 2025				875,800,000
Principal Amount, Total				1,378,500,000
Unamortized Discount, Net and Debt Issuance Costs				(4,700,000)
Total Long-term Debt Outstanding				1,373,800,000		1,386,200,000
Accounts Receivable and Accrued Unbilled Revenue
Accounts Receivable and Accrued Unbilled Revenues				85,000,000		101,100,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				1,263,900,000		1,512,800,000		$ 1,536,400,000
Proceeds on Sale of Receivables to AEP Credit
Proceeds from Sale of Receivables to AEP Credit				1,221,000,000		1,442,500,000		1,484,600,000
Financing Activities (Textuals)
Repayments of Long-term Debt				13,200,000		250,500,000		500,000
Proceeds from Issuance of Long-term Debt				$ 0		349,500,000		$ 0
Maximum Percentage Debt to Capitalization				67.50%
Dividend Restrictions				$ 182,300,000
Public Service Co Of Oklahoma [Member] | Utility [Member]
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				155,400,000		140,500,000
Maximum Loans to Money Pool				57,100,000		215,600,000
Average Borrowings from Money Pool				72,300,000		63,900,000
Average Loans to Money Pool				28,400,000		98,300,000
Net Loans (Borrowings) to/from Money Pool				(155,400,000)		38,800,000
Authorized Short Term Borrowing Limit				$ 300,000,000		$ 300,000,000
Maximum and Minimum Interest Rates
Maximum Interest Rate				2.70%		3.43%		2.97%
Minimum Interest Rate				0.27%		1.77%		1.81%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				0.92%		2.85%		2.27%
Average Interest Rate For Funds Loaned				1.95%		2.27%		1.98%
Southwestern Electric Power Co [Member]
Long-term Debt
Senior Unsecured Notes				$ 2,430,800,000		$ 2,428,900,000
Notes Payable	[3]			62,400,000		65,600,000
Other Long-term Debt				143,200,000		161,100,000
Total Long-term Debt Outstanding				2,636,400,000		2,655,600,000
Outstanding Long-term Debt
Principal Amount, 2021				106,200,000
Principal Amount, 2022				281,200,000
Principal Amount, 2023				6,200,000
Principal Amount, 2024				31,200,000
Principal Amount, 2025				6,200,000
Principal Amount, After 2025				2,225,500,000
Principal Amount, Total				2,656,500,000
Unamortized Discount, Net and Debt Issuance Costs				(20,100,000)
Total Long-term Debt Outstanding				2,636,400,000		2,655,600,000
Short-term Debt
Notes Payable				35,000,000		18,300,000
Accounts Receivable and Accrued Unbilled Revenue
Accounts Receivable and Accrued Unbilled Revenues				158,600,000		125,200,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				1,735,300,000		1,799,200,000		$ 1,817,000,000
Proceeds on Sale of Receivables to AEP Credit
Proceeds from Sale of Receivables to AEP Credit				1,593,800,000		1,618,500,000		1,736,100,000
Financing Activities (Textuals)
Repayments of Long-term Debt				21,200,000		59,700,000		794,500,000
Proceeds from Issuance of Long-term Debt				$ 0		0		1,065,700,000
Maximum Percentage Debt to Capitalization				67.50%
Dividend Restrictions				$ 571,900,000
Dividends Paid on Common Stock				$ (1,900,000)		(3,300,000)		$ (4,300,000)
Stock Issued During Period, Shares, Reverse Stock Splits				2,048
Stock Issued During Period, Shares, Stock Splits				1
Southwestern Electric Power Co [Member] | Utility [Member]
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Borrowings from Money Pool				$ 178,900,000		105,100,000
Maximum Loans to Money Pool				0		81,400,000
Average Borrowings from Money Pool				113,000,000		53,300,000
Average Loans to Money Pool				0		13,600,000
Net Loans (Borrowings) to/from Money Pool				(124,600,000)		(59,900,000)
Authorized Short Term Borrowing Limit				$ 350,000,000		$ 350,000,000
Maximum and Minimum Interest Rates
Maximum Interest Rate				2.70%		3.43%		2.97%
Minimum Interest Rate				0.27%		1.77%		1.81%
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				1.27%		2.72%		2.31%
Average Interest Rate For Funds Loaned				0.00%		2.22%		2.00%
Southwestern Electric Power Co [Member] | Nonutility [Member]
Maximum Interest Rate For Funds Loaned				2.70%		3.02%		2.97%
Minimum Interest Rate for Funds Loaned				0.27%		1.91%		1.83%
Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits
Maximum Loans to Money Pool				$ 2,100,000		$ 2,100,000
Average Loans to Money Pool				2,100,000		2,000,000
Net Loans (Borrowings) to/from Money Pool				$ 2,100,000		$ 2,100,000
Average Interest Rates for Funds Borrowed from and Loaned to Money Pool
Average Interest Rate For Funds Loaned				1.18%		2.55%		2.36%
Southwestern Electric Power Co [Member] | Loans Payable [Member]
Short-term Debt
Debt, Weighted Average Interest Rate	[9]			2.55%		3.29%
Senior Notes [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2020
Maturity Date High				2050
Weighted Average Interest Rate				3.97%
Senior Notes [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				0.70%		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				2022
Maturity Date High				2050
Weighted Average Interest Rate				3.70%
Senior Notes [Member] | AEP Texas Inc. [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.10%		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				2021
Maturity Date High				2050
Weighted Average Interest Rate				3.83%
Senior Notes [Member] | AEP Transmission Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.10%		3.10%
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				2050
Weighted Average Interest Rate				4.94%
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				4.82%
Senior Notes [Member] | Ohio Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.60%		4.00%
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				2021
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				6.63%		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	[13]			2020
Maturity Date High	[13]			2036
Weighted Average Interest Rate				2.39%
Pollution Control Bonds [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				0.18%		1.35%
Pollution Control Bonds [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				4.63%		5.38%
Pollution Control Bonds [Member] | AEP Texas Inc. [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low	[13]			2020
Maturity Date High	[13]			2030
Weighted Average Interest Rate				3.42%
Pollution Control Bonds [Member] | AEP Texas Inc. [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				0.90%		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%		4.55%
Pollution Control Bonds [Member] | Appalachian Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low	[13]			2020
Maturity Date High	[13]			2036
Weighted Average Interest Rate				1.77%
Pollution Control Bonds [Member] | Appalachian Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				0.19%		1.67%
Pollution Control Bonds [Member] | Appalachian Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				4.63%		5.38%
Pollution Control Bonds [Member] | Indiana Michigan Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low	[13]			2021
Maturity Date High	[13]			2025
Weighted Average Interest Rate				2.21%
Pollution Control Bonds [Member] | Indiana Michigan Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				0.18%		1.79%
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] | 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
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%
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%
Notes Payable, Other Payables [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2020
Maturity Date High				2032
Weighted Average Interest Rate				2.34%
Notes Payable, Other Payables [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				0.84%		2.42%
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				2020
Maturity Date High				2025
Weighted Average Interest Rate				1.06%
Notes Payable, Other Payables [Member] | Indiana Michigan Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				0.84%		2.42%
Notes Payable, Other Payables [Member] | Indiana Michigan Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.29%		2.80%
Notes Payable, Other Payables [Member] | Indiana Michigan Power Co [Member] | Subsequent Event [Member]
Financing Activities (Textuals)
Repayments of Long-term Debt		$ 7,000,000	$ 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				5.30%
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	[14]			2020
Maturity Date High	[14]			2029
Weighted Average Interest Rate				2.78%
Securitization Bonds [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.01%		1.98%
Securitization Bonds [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.77%		5.31%
Securitization Bonds [Member] | AEP Texas Inc. [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low	[14]			2020
Maturity Date High	[14]			2029
Weighted Average Interest Rate				2.55%
Securitization Bonds [Member] | AEP Texas Inc. [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.06%		1.98%
Securitization Bonds [Member] | AEP Texas Inc. [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.84%		5.31%
Securitization Bonds [Member] | AEP Texas Inc. [Member] | Subsequent Event [Member]
Financing Activities (Textuals)
Repayments of Long-term Debt		11,000,000
Securitization Bonds [Member] | Appalachian Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low	[14]			2023
Maturity Date High	[14]			2028
Weighted Average Interest Rate				3.29%
Securitization Bonds [Member] | Appalachian Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.01%		2.008%
Securitization Bonds [Member] | Appalachian Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.77%		3.772%
Securitization Bonds [Member] | Appalachian Power Co [Member] | Subsequent Event [Member]
Financing Activities (Textuals)
Repayments of Long-term Debt		12,000,000
Junior Subordinated Notes [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2022
Maturity Date High				2023
Weighted Average Interest Rate				2.32%
Junior Subordinated Notes [Member] | 2019 Equity Units [Member]
Financing Activities (Textuals)
Proceeds from Issuance of Debt						$ 805,000,000
Junior Subordinated Notes [Member] | 2020 Equity Units [Member]
Financing Activities (Textuals)
Proceeds from Issuance of Debt				$ 850,000,000
Junior Subordinated Notes [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.30%		3.40%
Junior Subordinated Notes [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				3.40%		3.40%
Other Long Term Debt [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2020
Maturity Date High				2059
Weighted Average Interest Rate				1.59%
Other Long Term Debt [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				0.81%		1.15%
Other Long Term Debt [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				13.72%		13.718%
Other Long Term Debt [Member] | AEP Texas Inc. [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2022
Maturity Date High				2059
Weighted Average Interest Rate				1.41%
Other Long Term Debt [Member] | AEP Texas Inc. [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.40%		3.05%
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				2022
Maturity Date High				2026
Weighted Average Interest Rate				1.51%
Other Long Term Debt [Member] | Appalachian Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.32%		2.97%
Other Long Term Debt [Member] | Appalachian Power Co [Member] | Maximum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				13.72%		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				1.49%
Other Long Term Debt [Member] | Indiana Michigan Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.28%		2.93%
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				2022
Maturity Date High				2027
Weighted Average Interest Rate				1.47%
Other Long Term Debt [Member] | Public Service Co Of Oklahoma [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				1.42%		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				3.00%		3.20%
Other Long Term Debt [Member] | Public Service Co Of Oklahoma [Member] | Subsequent Event [Member]
Financing Activities (Textuals)
Proceeds from Issuance of Long-term Debt			$ 400,000,000
Due Date			2022
Other Long Term Debt [Member] | Southwestern Electric Power Co [Member]
Long- term Debt by Type of Debt and Maturity
Maturity Date Low				2021
Maturity Date High				2035
Weighted Average Interest Rate				2.99%
Other Long Term Debt [Member] | Southwestern Electric Power Co [Member] | Minimum [Member]
Long- term Debt by Type of Debt and Maturity
Interest Rate				2.25%		3.08%
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		$ 9,000,000	$ 5,000,000
Due Date		2023	2023
Junior Subordinated Debt [Member] | 2019 Equity Units [Member]
Financing Activities (Textuals)
Debt Instrument, Interest Rate, Stated Percentage				3.40%
Junior Subordinated Debt [Member] | 2020 Equity Units [Member]
Financing Activities (Textuals)
Debt Instrument, Interest Rate, Stated Percentage				1.30%
Senior Unsecured Notes | Ohio Power Co [Member] | Subsequent Event [Member]
Financing Activities (Textuals)
Proceeds from Issuance of Long-term Debt			$ 450,000,000
Senior Unsecured Notes | Public Service Co Of Oklahoma [Member] | Subsequent Event [Member]
Financing Activities (Textuals)
Repayments of Long-term Debt		$ 250,000,000
Servicing Contracts [Member] | Appalachian Power Co [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				$ 5,200,000		$ 7,400,000		$ 7,000,000
Servicing Contracts [Member] | Indiana Michigan Power Co [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				7,900,000		11,100,000		9,200,000
Servicing Contracts [Member] | Ohio Power Co [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				24,100,000		27,100,000		26,300,000
Servicing Contracts [Member] | Public Service Co Of Oklahoma [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				4,800,000		7,800,000		7,900,000
Servicing Contracts [Member] | Southwestern Electric Power Co [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Revenue from Contracts with Customers				6,700,000		10,200,000		8,900,000
Retained Earnings [Member]
Financing Activities (Textuals)
Forward Equity Purchase Contract included in Current and Noncurrent liabilities				110,600,000		47,300,000		0
Dividends Paid on Common Stock				1,400,000,000		(1,300,000,000)		(1,300,000,000)
Additional Paid-in Capital [Member]
Financing Activities (Textuals)
Forward Equity Purchase Contract included in Current and Noncurrent liabilities				(85,800,000)	[15]	(9,800,000)	[16]	$ 21,800,000
Additional Paid-in Capital [Member] | 2019 Equity Units [Member]
Financing Activities (Textuals)
Forward Equity Purchase Contract included in Current and Noncurrent liabilities						$ 62,000,000
Additional Paid-in Capital [Member] | 2020 Equity Units [Member]
Financing Activities (Textuals)
Forward Equity Purchase Contract included in Current and Noncurrent liabilities				$ 121,000,000
[1]	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.
[2]	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. Consequently, these bonds have been classified for maturity purposes as Long-term Debt Due Within One Year - Nonaffiliated on the balance sheets.
[3]	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.
[4]	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.
[5]	See “Equity Units” section below for additional information.
[6]	Amount includes $805 million of Junior Subordinated Notes. See “Equity Units” section below for additional information.
[7]	Amount includes $850 million of Junior Subordinated Notes. See “Equity Units” section below for additional information.
[8]	Amount of securitized debt for receivables as accounted for under the “Transfers and Servicing” accounting guidance.
[9]	Weighted-average rate.
[10]	Includes the restrictions of consolidated and non-consolidated subsidiaries.
[11]	Amount represents the combined authorized short-term borrowing limit the State Transcos have from FERC or state regulatory commissions.
[12]	Amount represents the combined authorized short-term borrowing limit the State Transcos have from FERC or state regulatory commissions.
[13]	Certain Pollution Control Bonds are subject to redemption earlier than the maturity date.
[14]	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.
[15]	(c)    Includes $(121) million related to a forward equity purchase contract associated with the issuance of Equity Units. See “Equity Units” section of Note 14 for additional information.
[16]	(b)    Includes $(62) million related to a forward equity purchase contract associated with the issuance of Equity Units. See “Equity Units” section of Note 14 for additional information.

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - USD ($)		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
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		6,712,148
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	[1]	73,400	66,400	80,200
Vesting Period	[2]	(b)	(b)	(b)
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology
Weighted Average Grant Date Fair Value		$ 84.87	$ 88.73	$ 70.58
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	[3]	$ 53,800,000	$ 57,900,000	$ 53,200,000
Actual Tax Benefit Realized		7,200,000	8,400,000	7,700,000
Total Compensation Cost Capitalized		20,400,000	$ 20,000,000	$ 19,700,000
Stock Based Compensation (Textuals)
Total Unrecognized Compensation Cost Related to Unvested Share-based Compensation Arrangements Granted		$ 78,000,000
Weighted-average Period of Unrecognized Compensation Costs (in years)		1.39 years
Stock Unit Accumulation Plan for Non Employee Directors [Member]
Stock Based Compensation (Textuals)
Number of Years After Termination of Board Service Participant Can Elect to Have Stock Units Paid in Cash		10 years
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology
Weighted Average Grant Date Fair Value		$ 83.80	$ 89.13	$ 70.41
Awarded Units		12,100	10,000	11,400
Restricted Stock Units (RSUs) [Member]
Total Fair Value and Total Intrinsic Value of Restricted Shares and Restricted Stock Units Vested
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value		$ 22,900,000	$ 16,300,000	$ 16,600,000
Intrinsic Value of Restricted Shares and Restricted Stock Units Vested	[4]	$ 25,200,000	$ 21,600,000	$ 19,200,000
Status of Nonvested Restricted Shares and Restricted Stock Units
Nonvested, Shares/Units, Beginning Balance		516,900
Nonvested, Weighted Average Grant Date Fair Value, Beginning of Period		$ 75.55
Shares/Units, Vested		(307,600)
Weighted Average Grant Date Fair Value, Vested		$ 74.58
Shares/Units, Forfeited		(30,000)
Weighted Average Grant Date Fair Value, Shares/Units, Forfeited		$ 84.27
Nonvested, Shares/Units, Ending Balance		448,000	516,900
Nonvested, Weighted Average Grant Date Fair Value, End of Period		$ 86.56	$ 75.55
Stock Based Compensation (Textuals)
Maximum Contractual Term of Outstanding Restricted Stock Units (in months)		40 months
Total Aggregate Intrinsic Value of Nonvested Shares		$ 37,000,000
Weighted Average Remaining Contractual Life of Nonvested Shares (in years)		1.6 years
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology
Weighted Average Grant Date Fair Value		$ 94.38	$ 81.57	$ 67.96
Awarded Units		268,700	304,800	260,000
Performance Units [Member]
Performance Units
Awarded Units		424,800	535,000	581,400
Vesting Period (in years)		3 years	3 years	3 years
Certified Performance Scores and Units Earned
Certified Performance Score		128.20%	132.70%	136.70%
Performance Units Earned		757,858	792,897	820,780
Performance Units Manditorily Deferred as AEP Career Shares		13,614	10,063	11,248
Performance Units Voluntarily Deferred into the Incentive Compensation Deferral Program		26,936	49,392	56,826
Share Based Compensation Performance Units to be Settled in Shares	[5]	717,308	733,442
Performance Units to be Paid in Cash	[5]			752,706
Cash Payouts
Cash Payouts for Performance Units		$ 0	$ 58,300,000	$ 66,900,000
Equity Payouts for Performance Units		$ 75,400,000	0	0
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		$ 1,900,000	$ 6,600,000	$ 5,100,000
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	[6]	2 years 10 months 13 days	2 years 10 months 13 days	2 years 10 months 13 days
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum		13.67%	14.83%	14.77%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum		28.15%	25.57%	26.72%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate		1.40%	2.49%	2.34%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	[7]	0.00%	0.00%	0.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Weighted Average Volatility Rate		16.39%	17.39%	17.90%
Weighted Average Grant Date Fair Value		$ 116.56	$ 83.21	$ 67.21
Performance Units and Reinvested Dividends [Member]
Share Based Compensation Performance Units Converted to Shares	[8]	717,000
Performance Units
Awarded Units		53,800
Status of Nonvested Restricted Shares and Restricted Stock Units
Nonvested, Shares/Units, Beginning Balance		1,113,400
Nonvested, Weighted Average Grant Date Fair Value, Beginning of Period		$ 73.64
Shares/Units, Vested	[8]	(597,000)
Weighted Average Grant Date Fair Value, Vested		$ 66.45
Shares/Units, Forfeited		(56,400)
Weighted Average Grant Date Fair Value, Shares/Units, Forfeited		$ 87.58
Nonvested, Shares/Units, Ending Balance		938,600	1,113,400
Nonvested, Weighted Average Grant Date Fair Value, End of Period		$ 98.05	$ 73.64
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology
Weighted Average Grant Date Fair Value		$ 84.91
Severance Grant
Total Fair Value and Total Intrinsic Value of Restricted Shares and Restricted Stock Units Vested
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value		$ 5,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology
Weighted Average Grant Date Fair Value		$ 83.74
Awarded Units		64,186
[1]	All awarded dividends in both 2020 and 2019 were equity awards and awarded dividends in 2018 were a mix of equity awards and liability awards.
[2]	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.
[3]	Compensation cost for share-based payment arrangements is included in Other Operation and Maintenance expenses on the statements of income.
[4]	Intrinsic value is calculated as market price at the vesting date.
[5]	Performance shares settled for the three-year periods ended December 31, 2020 and 2019 settled in AEP common stock. Performance units settled for the three-year period ended December 31, 2018 settled in cash. In all cases, the settlement of common stock or cash occurs in the quarter following the end of the year shown.
[6]	Period from award date to vesting date.
[7]	Equivalent to reinvesting dividends.
[8]	The vested Performance Shares will be converted to 717 thousand shares based on the closing share price on the day before settlement.

Related Party Transactions (Det

Related Party Transactions (Details) $ in Millions		3 Months Ended	12 Months Ended
		Jun. 30, 2019MW	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Affiliated Revenues and Purchases
Affiliated Revenues			$ 0	$ 0	$ 0
Charitable Contribution to AEP Foundation [Abstract]
Related Party Charitable Contribuions to AEP Foundation				50
Generation and Marketing [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			104.6	135.8	122.2
Appalachian Power Co. to AEP Transmission Co [Member]
Joint License Agreement
Joint License Agreement			$ 0.9	0.2	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			$ 12	13	12
Railcar Maintenance			$ 0.9	1.3	1.5
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			$ 0.7	0.8	0.7
AEP Generating Co To Southwestern Electric Power Co [Member]
Cook Coal Terminal
Railcar Maintenance			3	4	3.4
AEP Energy Partners, Inc. to AEP Texas Inc. [Member]
Oklaunion PPA between AEP Texas and AEPEP
Oklaunion Purchase Power Agreement			88	157	104
Indiana Michigan Power Co to AEP Transmission Co [Member]
Joint License Agreement
Joint License Agreement			3	1.5	2.2
Kentucky Power Co to AEP Transmission Co [Member]
Joint License Agreement
Joint License Agreement			0.4	0.3	0.2
Ohio Power Co to AEP Transmission Co [Member]
Joint License Agreement
Joint License Agreement			4.5	2.2	2.9
Public Service Co of Oklahoma to AEP Transmission Co [Member]
Joint License Agreement
Joint License Agreement			0.4	0.3	0.3
Wheeling Power Co to AEP Transmission Co [Member]
Joint License Agreement
Joint License Agreement			0.2	0.1	0
AEP Wind Holdings LLC [Member]
Sempra Renewables LLC PPAs [Abstract]
WindGenerationMWs | MW		724
AEP Wind Holdings LLC [Member] | Generation and Marketing [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			10.6	14.9	19.9
AEP Generation Resources [Member]
Central Machine Shop
Billings for Services from Central Machine Shop Facility			2.9	0.8	1.6
AEP Transmission Co [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			896.3	806.7	598.9
Sales and Purchases of Property
Related Party Sales of Property			0.2	0	0
Related Party Purchases of Property			6	10.2	18.5
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] | 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			885	795.5	591.4
AEP Transmission Co [Member] | Other Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			11.3	11.2	7.5
Appalachian Power Co [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			174.7	205.3	181.4
Transmission Service Charges
PJM Net Transmission Service Charges			243.2	222.3	128.3
Barging, Urea Transloading and Other Services
Expenses from Barging, Urea Transloading and Other Services			43.7	38.9	35.1
Sales and Purchases of Property
Related Party Sales of Property			5.7	5.5	5.4
Related Party Purchases of Property			1.3	6	0.6
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			112.5	128.6	133.2
Appalachian Power Co [Member] | Auction Sales to OPCo [Member]
Affiliated Revenues and Purchases
Affiliated Revenues	[1]		5.3	11.4	5.8
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			49.1	58.5	36.4
Appalachian Power Co [Member] | Other Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			7.8	6.8	6
Indiana Michigan Power Co [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			10.5	10.5	22.1
Cost of Purchased Power from Affiliate			172.8	214.9	237.9
Transmission Service Charges
PJM Net Transmission Service Charges			145.9	143.5	91.4
Central Machine Shop
Billings for Services from Central Machine Shop Facility			3.2	2.3	2.4
Sales and Purchases of Property
Related Party Sales of Property			1.5	7.5	8.2
Related Party Purchases of Property			3.4	0.9	2
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	[1]		0	0	0
Indiana Michigan Power Co [Member] | Auction Purchases From AEP Energy [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate	[1]		0	0	0
Indiana Michigan Power Co [Member] | Auction Purchases from AEPSC [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate	[1]		0	0	0
Indiana Michigan Power Co [Member] | Direct Purchases from AEGCo [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate			172.8	214.9	237.9
Indiana Michigan Power Co [Member] | Direct Sales to East Affiliates [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			0	0	0.1
Indiana Michigan Power Co [Member] | Auction Sales to OPCo [Member]
Affiliated Revenues and Purchases
Affiliated Revenues	[1]		3.1	6.7	7.1
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			2.9	0.7	11.7
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			4.5	3.1	3.2
Indiana Michigan Power Co [Member] | AEP Wind Holdings LLC [Member] | Generation and Marketing [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate			11	9
Kentucky Power Co [Member]
Barging, Urea Transloading and Other Services
Expenses from Barging, Urea Transloading and Other Services			3.2	4.8	4.2
Central Machine Shop
Billings for Services from Central Machine Shop Facility			0.9	1.4	1.7
Ohio Power Co [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			41.5	27.3	21
Cost of Purchased Power from Affiliate			119.7	156	135.3
Transmission Service Charges
PJM Net Transmission Service Charges			417.4	373.4	210.1
Sales and Purchases of Property
Related Party Sales of Property			7	7	10.7
Related Party Purchases of Property			1.2	3	2.8
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	[1]		51	64.6	79.7
Ohio Power Co [Member] | Auction Purchases From AEP Energy [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate	[1]		58.7	69.9	41
Ohio Power Co [Member] | Auction Purchases from AEPSC [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate	[1]		10	21.5	14.6
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] | 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			16.6	7.7	3.9
Ohio Power Co [Member] | Other Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			24.9	19.6	17.1
Ohio Power Co [Member] | AEP Wind Holdings LLC [Member] | Generation and Marketing [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate			23	17
Public Service Co Of Oklahoma [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			5.2	6.1	5.4
Transmission Service Charges
SPP Net Transmission Service Charges			69.7	46.9	65.9
Central Machine Shop
Billings for Services from Central Machine Shop Facility			0.9	1.1	0.5
Sales and Purchases of Property
Related Party Sales of Property			1.1	0.8	1
Related Party Purchases of Property			0.4	0.5	1.3
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] | 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			0	1.3	0.9
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			5.2	4.8	4.5
Southwestern Electric Power Co [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			41	36.9	35.1
Revenue from Related Parties, Net			39	4.9	28.4
Transmission Service Charges
SPP Net Transmission Service Charges			31.3	20.1	10.5
Central Machine Shop
Billings for Services from Central Machine Shop Facility			0.5	1.1	0.7
Sales and Purchases of Property
Related Party Sales of Property			0.8	0.2	0.8
Related Party Purchases of Property			2.8	0.7	0.8
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] | 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	(0.1)	0
Southwestern Electric Power Co [Member] | Transmission Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			37.4	3.6	26.9
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			1.6	1.4	1.5
Southwestern Electric Power Co [Member] | AEP Wind Holdings LLC [Member] | Generation and Marketing [Member]
Affiliated Revenues and Purchases
Cost of Purchased Power from Affiliate			14	10
Wheeling Power Co [Member] [Domain]
Barging, Urea Transloading and Other Services
Expenses from Barging, Urea Transloading and Other Services			3.3	4.8	4.2
AEP Texas Inc. [Member]
Affiliated Revenues and Purchases
Affiliated Revenues			90.8	160.5	105.2
ERCOT Transmission Service Charges
Billings from ETT for ERCOT Wholesale Transmission Services			28	27	27
Sales and Purchases of Property
Related Party Sales of Property			0.9	0.9	0.3
Related Party Purchases of Property			$ 1.5	0.3	0.1
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] | 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			87.5	157.2	103.6
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	$ 3.3	$ 1.6
[1]	Refer to the Ohio Auctions section below for further information regarding these amounts.

Variable Interest Entities (Det

Variable Interest Entities (Details) $ in Millions		12 Months Ended
		Dec. 31, 2020USD ($)MW		Dec. 31, 2019USD ($)		Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
ASSETS
Current Assets		$ 4,351.5		$ 4,077.8
Net Property, Plant and Equipment		63,901.6		60,138.1
Other Noncurrent Assets		12,504.1		11,676.4
Total Assets		80,757.2		75,892.3		$ 68,802.8
LIABILITIES AND EQUITY
Current Liabilities		9,926.7		10,299.1
Noncurrent Liabilities		50,010.8		45,571.4
Equity		20,774.5		19,913.2		19,059.4	$ 18,313.6
Total Liabilities and Equity		80,757.2		75,892.3
Variable Interest Entities (Textuals)
Securitization Bonds		716.4		1,025.1
Securitized Assets		657		858.1
Redeemable Noncontrolling Interest		0		65.7
Equity Method Investments		1,406.3		1,356.6
Equity Method Investment Income		91.1		72.1		$ 73.1
Unregulated Operation [Member]
ASSETS
Net Property, Plant and Equipment		1,927		1,757.7
Variable Interest Entities (Textuals)
Depreciable Life Ranges - Transmission						40 years
Protected Cell Of Energy Insurance Services, Inc. [Member]
Variable Interest Entities (Textuals)
Insurance Premium Expense to Protected Cell		31		34		$ 34
Protected Cell Of Energy Insurance Services, Inc. [Member] | Variable Interest Entities [Member]
ASSETS
Current Assets		198.1		194.6
Net Property, Plant and Equipment		0		0
Other Noncurrent Assets		0		0
Total Assets		198.1		194.6
LIABILITIES AND EQUITY
Current Liabilities		43.1		40.7
Noncurrent Liabilities		62.5		78
Equity		92.5		75.9
Total Liabilities and Equity		$ 198.1		194.6
Transource Energy [Member]
Variable Interest Entities (Textuals)
Debt-to-Total Capitalization Maximum		67.50%
Transource Energy [Member] | Variable Interest Entities [Member]
ASSETS
Current Assets		$ 22.2		25.8
Net Property, Plant and Equipment		458.7		424.1
Other Noncurrent Assets		3.7		3.2
Total Assets		484.6		453.1
LIABILITIES AND EQUITY
Current Liabilities		32.6		192.4
Noncurrent Liabilities		185		4.8
Equity		267		255.9
Total Liabilities and Equity		$ 484.6		453.1
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		$ 0		66
Trent and Desert Sky Wind Farms [Member] | Variable Interest Entities [Member]
ASSETS
Current Assets				7.8
Net Property, Plant and Equipment				330.6
Other Noncurrent Assets				10.1
Total Assets				348.5
LIABILITIES AND EQUITY
Current Liabilities				5.5
Noncurrent Liabilities				15.8
Equity				327.2
Total Liabilities and Equity				348.5
Apple Blossom and Black Oak [Member]
Variable Interest Entities (Textuals)
Noncontrolling Interest in Variable Interest Entity		119		128
HLBV Income for Noncontrolling Interests		6		6
Apple Blossom and Black Oak [Member] | Variable Interest Entities [Member]
ASSETS
Current Assets		9.6		10.1
Net Property, Plant and Equipment		223.1		231.4
Other Noncurrent Assets		12.1		13.1
Total Assets		244.8		254.6
LIABILITIES AND EQUITY
Current Liabilities		5.3		5.4
Noncurrent Liabilities		4.9		4.7
Equity		234.6		244.5
Total Liabilities and Equity		244.8		254.6
Santa Rita East [Member]
Variable Interest Entities (Textuals)
Noncontrolling Interest in Variable Interest Entity		$ 61		118
Percentage of an Asset Acquired		85.00%
Production Tax Credits		$ 23		10
Santa Rita East [Member] | Variable Interest Entities [Member]
ASSETS
Current Assets		6		17.7
Net Property, Plant and Equipment		453.1		465.2
Other Noncurrent Assets		0		0.3
Total Assets		459.1		483.2
LIABILITIES AND EQUITY
Current Liabilities		3.5		3.9
Noncurrent Liabilities		6.7		7.5
Equity		448.9		471.8
Total Liabilities and Equity		$ 459.1		483.2
Santa Rita East [Member] | Initial Interest Acquired [Member]
Variable Interest Entities (Textuals)
Percentage of an Asset Acquired		75.00%
Santa Rita East [Member] | Additional 10 Percent [Member]
Variable Interest Entities (Textuals)
Percentage of an Asset Acquired		10.00%
AEP Credit, Inc.
Variable Interest Entities (Textuals)
Minimum Percentage of Equity AEP Provides		5.00%
Percentage Of Short Term Borrowing Needs In Excess Of Third Party Financings		25.00%
AEP Credit, Inc. | Variable Interest Entities [Member]
ASSETS
Current Assets		$ 960.4		842.8
Net Property, Plant and Equipment		0		0
Other Noncurrent Assets		12.9		7.1
Total Assets		973.3		849.9
LIABILITIES AND EQUITY
Current Liabilities		827.2		805.2
Noncurrent Liabilities		0.8		0.9
Equity		145.3		43.8
Total Liabilities and Equity		973.3		849.9
Dolet Hills Lignite Co, LLC [Member]
Variable Interest Entities (Textuals)
Equity Method Investment Income		$ 2.9		3		2.7
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		$ 1,300		1,400
Capital Contribution From Parent [Member] | Ohio Valley Electric Corporation [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
Retained Earnings [Member]
LIABILITIES AND EQUITY
Equity		10,687.8		9,900.9		9,325.3	8,626.7
AEP's Ratio of OVEC Debt [Member] | Ohio Valley Electric Corporation [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet		0		0
Maximum Exposure	[1]	555		588.9
Total Investment [Member] | Ohio Valley Electric Corporation [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet		4.4		4.4
Maximum Exposure		559.4		593.3
Non-Affiliate Contribution [Member] | Trent and Desert Sky Wind Farms [Member] | Variable Interest Entities [Member]
ASSETS
Net Property, Plant and Equipment		$ 84
Total Generation MWs [Member] | Santa Rita East [Member]
Variable Interest Entities (Textuals)
WindGenerationMWs | MW		302
Long-term PPA MWs [Member] | Santa Rita East [Member]
Variable Interest Entities (Textuals)
WindGenerationMWs | MW		260
Sold at Wholesale MWs [Member] | Santa Rita East [Member]
Variable Interest Entities (Textuals)
WindGenerationMWs | MW		42
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]
ASSETS
Current Assets		$ 235.8		197.4
Net Property, Plant and Equipment		10,772.8		9,490.9
Other Noncurrent Assets		237.4		202.5
Total Assets		11,246		9,890.8		8,394.1
LIABILITIES AND EQUITY
Current Liabilities		1,137.5		1,093.1
Noncurrent Liabilities		5,395.6		4,788.2
Total Liabilities and Equity		11,246		9,890.8
AEP Transmission Co [Member] | Unregulated Operation [Member]
ASSETS
Net Property, Plant and Equipment		0.7		1.4
AEP Transmission Co [Member] | Billings from AEP Service Corporation [Member]
Variable Interest Entities (Textuals)
Billings from VIE		270.3		242.3		220.4
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		45.9		33.4
Maximum Exposure		45.9		33.4
Appalachian Power Co [Member]
ASSETS
Current Assets		674.1		700.6
Net Property, Plant and Equipment		11,394.1		11,081.9
Other Noncurrent Assets		1,247		985.8
Total Assets		13,315.2		12,768.3
LIABILITIES AND EQUITY
Current Liabilities		1,217.7		1,226
Noncurrent Liabilities		7,753.2		7,369.9
Equity		4,344.3		4,172.4		4,006.1	3,804.5
Total Liabilities and Equity		13,315.2		12,768.3
Variable Interest Entities (Textuals)
Securitization Bonds		223.8		248.3
Securitized Assets		210.1		234.7
Amount Of Power Purchased From OVEC		94.4		104.5		100.4
Appalachian Power Co [Member] | Unregulated Operation [Member]
ASSETS
Net Property, Plant and Equipment		24		22.6
Appalachian Power Co [Member] | Appalachian Consumer Rate Relief Funding [Member]
Variable Interest Entities (Textuals)
Securitized Assets		210		235
Appalachian Power Co [Member] | Appalachian Consumer Rate Relief Funding [Member] | Variable Interest Entities [Member]
ASSETS
Current Assets		16.8		21.5
Net Property, Plant and Equipment		0		0
Other Noncurrent Assets		212.7	[2]	237.5	[3]
Total Assets		229.5		259
LIABILITIES AND EQUITY
Current Liabilities		28.7		28.3
Noncurrent Liabilities		198.9		228.8
Equity		1.9		1.9
Total Liabilities and Equity		$ 229.5		259
Appalachian Power Co [Member] | Ohio Valley Electric Corporation [Member]
Variable Interest Entities (Textuals)
Power Participation Ratio		15.69%
Outstanding Indebtedness		$ 200		213
Appalachian Power Co [Member] | Billings from AEP Service Corporation [Member]
Variable Interest Entities (Textuals)
Billings from VIE		294.9		308.3		295.6
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		42.8		44.1
Maximum Exposure		42.8		44.1
Appalachian Power Co [Member] | Retained Earnings [Member]
LIABILITIES AND EQUITY
Equity		2,248		2,078.3		1,922	1,714.1
Appalachian Power Co [Member] | Other Noncurrent Assets [Member] | Appalachian Consumer Rate Relief Funding [Member]
Variable Interest Entities (Textuals)
Intercompany Item Eliminated in Consolidation		3		3
Appalachian Power Co [Member] | Current Liabilities [Member] | Appalachian Consumer Rate Relief Funding [Member]
Variable Interest Entities (Textuals)
Securitization Bonds		25		25
Appalachian Power Co [Member] | Noncurrent Liabilities [Member] | Appalachian Consumer Rate Relief Funding [Member]
Variable Interest Entities (Textuals)
Securitization Bonds		199		223
Indiana Michigan Power Co [Member]
ASSETS
Current Assets		418.8		403
Net Property, Plant and Equipment		7,052.3		6,899.7
Other Noncurrent Assets		4,167.2		3,934.7
Total Assets		11,638.3		11,237.4
LIABILITIES AND EQUITY
Current Liabilities		1,104.5		883.4
Noncurrent Liabilities		7,784.6		7,809.6
Equity		2,749.2		2,544.4		2,352.8	2,217.6
Total Liabilities and Equity		11,638.3		11,237.4
Variable Interest Entities (Textuals)
Amount Of Power Purchased From OVEC		47.2		52.3		50.2
Indiana Michigan Power Co [Member] | Unregulated Operation [Member]
ASSETS
Net Property, Plant and Equipment		28.2		28.8
Indiana Michigan Power Co [Member] | DCC Fuel [Member]
Variable Interest Entities (Textuals)
Payments Made by I&M to DCC Fuel		94		95		113
Indiana Michigan Power Co [Member] | DCC Fuel [Member] | Variable Interest Entities [Member]
ASSETS
Current Assets		76.1		86.5
Net Property, Plant and Equipment		138.9		156.8
Other Noncurrent Assets		70.9		82.5
Total Assets		285.9		325.8
LIABILITIES AND EQUITY
Current Liabilities		76		86.4
Noncurrent Liabilities		209.9		239.4
Equity		0		0
Total Liabilities and Equity		$ 285.9		325.8
Indiana Michigan Power Co [Member] | Ohio Valley Electric Corporation [Member]
Variable Interest Entities (Textuals)
Power Participation Ratio		7.85%
Outstanding Indebtedness		$ 100		106
Indiana Michigan Power Co [Member] | Billings from AEP Service Corporation [Member]
Variable Interest Entities (Textuals)
Billings from VIE		210.2		184.8		173.5
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		27.1		28.6
Maximum Exposure		27.1		28.6
Indiana Michigan Power Co [Member] | Billings from AEP Generating Company [Member]
Variable Interest Entities (Textuals)
Billings from VIE		173		215		238
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		$ 9		10
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] | Retained Earnings [Member]
LIABILITIES AND EQUITY
Equity		$ 1,718.7		1,518.5		1,329.1	1,192.2
Ohio Power Co [Member]
ASSETS
Current Assets		256.3		238.5
Net Property, Plant and Equipment		7,452.1		6,907
Other Noncurrent Assets		1,002		898.1
Total Assets		8,710.4		8,043.6
LIABILITIES AND EQUITY
Current Liabilities		1,906.2		1,297.9
Noncurrent Liabilities		4,111.5		4,237.2
Equity		2,692.7		2,508.5		2,297.4	2,310.3
Total Liabilities and Equity		8,710.4		8,043.6
Variable Interest Entities (Textuals)
Amount Of Power Purchased From OVEC		120.8		132.7		127.5
Ohio Power Co [Member] | Unregulated Operation [Member]
ASSETS
Net Property, Plant and Equipment		$ 9.9		9.8
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		$ 255		270
Ohio Power Co [Member] | Billings from AEP Service Corporation [Member]
Variable Interest Entities (Textuals)
Billings from VIE		232.8		230.4		214.9
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		33.9		33.2
Maximum Exposure		33.9		33.2
Ohio Power Co [Member] | Retained Earnings [Member]
LIABILITIES AND EQUITY
Equity		1,532.7		1,348.5		1,136.4	1,148.4
Public Service Co Of Oklahoma [Member]
ASSETS
Current Assets		181.3		188.2
Net Property, Plant and Equipment		4,320		4,103.3
Other Noncurrent Assets		489.4		460
Total Assets		4,990.7		4,751.5
LIABILITIES AND EQUITY
Current Liabilities		478.6		445.8
Noncurrent Liabilities		2,966.5		2,932.4
Equity		1,545.6		1,373.3		1,248	1,215.3
Total Liabilities and Equity		4,990.7		4,751.5
Public Service Co Of Oklahoma [Member] | Unregulated Operation [Member]
ASSETS
Net Property, Plant and Equipment		6.9		4.7
Public Service Co Of Oklahoma [Member] | Billings from AEP Service Corporation [Member]
Variable Interest Entities (Textuals)
Billings from VIE		113.2		125.7		121.5
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		15.7		18.1
Maximum Exposure		15.7		18.1
Public Service Co Of Oklahoma [Member] | Retained Earnings [Member]
LIABILITIES AND EQUITY
Equity		974.3		851		724.7	691.5
Southwestern Electric Power Co [Member]
ASSETS
Current Assets		428		354.1
Net Property, Plant and Equipment		7,088.2		7,095.2
Other Noncurrent Assets		637.9		382.9
Total Assets		8,154.1		7,832.2
LIABILITIES AND EQUITY
Current Liabilities		763.6		674.7
Noncurrent Liabilities		4,762.8		4,716.4
Equity		2,627.7		2,441.1		2,315.6	2,234.5
Total Liabilities and Equity		8,154.1		7,832.2
Variable Interest Entities (Textuals)
Equity Method Investment Income		2.9		3		2.7
Southwestern Electric Power Co [Member] | Unregulated Operation [Member]
ASSETS
Net Property, Plant and Equipment		97.8		112.1
Southwestern Electric Power Co [Member] | Sabine Mining Co [Member]
Variable Interest Entities (Textuals)
Billings from VIE		131		110		152
Guarantees Of Mine Reclamation Amount		155
Estimated Final Cost Mine Reclamation		104
Amount Collected, Rider Mine Close Other Assets Noncurrent		8
Amount Collected Through Rider For Final Mine Closure And Reclamation Costs		81
Amount Collected, Rider Mine Close ARO Noncurrent		89
Southwestern Electric Power Co [Member] | Sabine Mining Co [Member] | Variable Interest Entities [Member]
ASSETS
Current Assets		88		80
Net Property, Plant and Equipment		97.3		111.6
Other Noncurrent Assets		99.3		93.2
Total Assets		284.6		284.8
LIABILITIES AND EQUITY
Current Liabilities		57.7		50.6
Noncurrent Liabilities		225.3		233.6
Equity		1.6		0.6
Total Liabilities and Equity		284.6		284.8
Southwestern Electric Power Co [Member] | Dolet Hills Lignite Co, LLC [Member]
Variable Interest Entities (Textuals)
Billings from VIE		$ 142		55		58
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		$ 2.9		3		2.7
Southwestern Electric Power Co [Member] | Billings from AEP Service Corporation [Member]
Variable Interest Entities (Textuals)
Billings from VIE		161.8		169.5		164.4
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		22		23.4
Maximum Exposure		22		23.4
Southwestern Electric Power Co [Member] | Capital Contribution From Parent [Member] | Dolet Hills Lignite Co, LLC [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] | Retained Earnings [Member]
LIABILITIES AND EQUITY
Equity		1,811.9		1,629.5		1,508.4	1,426.6
Southwestern Electric Power Co [Member] | Retained Earnings [Member] | Dolet Hills Lignite Co, LLC [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet		20.4		17.5
Maximum Exposure		20.4		17.5
Southwestern Electric Power Co [Member] | SWEPCo's Share of Obligations [Member] | Dolet Hills Lignite Co, LLC [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet		0		0
Maximum Exposure		98.5		130
Southwestern Electric Power Co [Member] | Total Investment [Member] | Dolet Hills Lignite Co, LLC [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
As Reported on the Balance Sheet		28		25.1
Maximum Exposure		$ 126.5		155.1
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]
ASSETS
Current Assets		$ 310.9		692.9
Net Property, Plant and Equipment		9,813.6		8,845.1
Other Noncurrent Assets		905.7		1,051.1
Total Assets		11,030.2		10,589.1
LIABILITIES AND EQUITY
Current Liabilities		676.8		1,027.2
Noncurrent Liabilities		7,147.4		6,600.8
Equity		3,206		2,961.1		2,580.5	2,169.9
Total Liabilities and Equity		11,030.2		10,589.1
Variable Interest Entities (Textuals)
Securitization Bonds		492.6		776.8
Securitized Assets		$ 446.8		623.4
Jointly Owned Utility Plant, Proportionate Ownership Share		54.69%
Accumulated Provisions For Rate Refunds		$ 20.1		64.7
AEP Texas Inc. [Member] | Unregulated Operation [Member]
ASSETS
Net Property, Plant and Equipment		1.2		61.1
AEP Texas Inc. [Member] | AEP Texas Central Transition Funding Co [Member]
Variable Interest Entities (Textuals)
Securitized Assets		242		389
AEP Texas Inc. [Member] | AEP Texas Central Transition Funding Co [Member] | Variable Interest Entities [Member]
ASSETS
Current Assets		61.2		187
Net Property, Plant and Equipment		0		0
Other Noncurrent Assets		273.9	[4]	428.1	[5]
Total Assets		335.1		615.1
LIABILITIES AND EQUITY
Current Liabilities		69.8		280.2
Noncurrent Liabilities		246.5		316.3
Equity		18.8		18.6
Total Liabilities and Equity		335.1		615.1
AEP Texas Inc. [Member] | Restoration Funding [Member]
Variable Interest Entities (Textuals)
Securitized Assets		205		232
AEP Texas Inc. [Member] | Restoration Funding [Member] | Variable Interest Entities [Member]
ASSETS
Current Assets		23.3		9.4
Net Property, Plant and Equipment		0		0
Other Noncurrent Assets		214.9	[6]	234.4	[7]
Total Assets		238.2		243.8
LIABILITIES AND EQUITY
Current Liabilities		33.9		16.3
Noncurrent Liabilities		203.1		226.3
Equity		1.2		1.2
Total Liabilities and Equity		238.2		243.8
AEP Texas Inc. [Member] | Billings from AEP Service Corporation [Member]
Variable Interest Entities (Textuals)
Billings from VIE		199.4		206.6		184.3
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		30.5		32.4
Maximum Exposure		30.5		32.4
AEP Texas Inc. [Member] | Retained Earnings [Member]
LIABILITIES AND EQUITY
Equity		1,757		1,516		1,337.7	$ 1,124.6
AEP Texas Inc. [Member] | Other Noncurrent Assets [Member] | AEP Texas Central Transition Funding Co [Member]
Variable Interest Entities (Textuals)
Intercompany Item Eliminated in Consolidation		32		39
AEP Texas Inc. [Member] | Other Noncurrent Assets [Member] | Restoration Funding [Member]
Variable Interest Entities (Textuals)
Intercompany Item Eliminated in Consolidation		9		1
AEP Texas Inc. [Member] | Current Liabilities [Member] | AEP Texas Central Transition Funding Co [Member]
Variable Interest Entities (Textuals)
Securitization Bonds		66		267
AEP Texas Inc. [Member] | Current Liabilities [Member] | Restoration Funding [Member]
Variable Interest Entities (Textuals)
Securitization Bonds		23		14
AEP Texas Inc. [Member] | Noncurrent Liabilities [Member] | AEP Texas Central Transition Funding Co [Member]
Variable Interest Entities (Textuals)
Securitization Bonds		209		274
AEP Texas Inc. [Member] | Noncurrent Liabilities [Member] | Restoration Funding [Member]
Variable Interest Entities (Textuals)
Securitization Bonds		$ 195		221
Joint Venture Wind Farms [Member]
Variable Interest Entities (Textuals)
Equity Method Investment, Ownership Percentage		50.00%
Production Tax Credits		$ 36		27
Equity Method Investments		376		394
Historical Investment Balance		399
Historical Investment Basis Difference		(12)
Equity Method Investment Income		$ 2		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		50.00%
BP Wind Energy [Member]
Variable Interest Entities (Textuals)
Equity Method Investment, Ownership Percentage		50.00%
ETT [Member]
Variable Interest Entities (Textuals)
Equity Method Investments		$ 732		695
Equity Method Investment Income		$ 68		$ 66		$ 62
[1]	Based on the Registrants’ power participation ratios APCo, I&M and OPCo’s share of OVEC debt was $200 million, $100 million and $255 million as of December 31, 2020 and $213 million, $106 million and $270 million as of December 31, 2019, respectively.
[2]	Includes an intercompany item eliminated in consolidation of $3 million.
[3]	Includes an intercompany item eliminated in consolidation of $3 million.
[4]	Includes an intercompany item eliminated in consolidation of $32 million.
[5]	Includes an intercompany item eliminated in consolidation of $39 million.
[6]	Includes an intercompany item eliminated in consolidation of $9 million.
[7]	Includes an intercompany item eliminated in consolidation of $1 million.

Property, Plant and Equipment_3

Property, Plant and Equipment (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020		Dec. 31, 2019	Dec. 31, 2018
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		$ 23,133.9		$ 22,762.4
Property, Plant and Equipment, Transmission		27,886.7		24,808.6
Property, Plant and Equipment, Distribution		23,972.1		22,443.4
Property, Plant and Equipment, Other		5,294.6		4,811.5
Property, Plant and Equipment, Construction Work in Progress		4,025.7		4,319.8
Accumulated Depreciation		20,411.4		19,007.6
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		63,901.6		60,138.1
Asset Retirement Obligations (ARO)
Beginning Balance	[1],[2],[3],[4]	2,418.9		2,355.5
Accretion Expense	[1],[2],[3],[4]	102.4		102.5
Liabilities Incurred	[1],[2],[3],[4]	0.3		12
Liabilities Settled	[1],[2],[3],[4]	(188)		(118.1)
Revisions in Cash Flow Estimates	[1],[2],[3],[4],[5]	183.1		67
Ending Balance	[1],[2],[3],[4]	2,516.7		2,418.9	$ 2,355.5
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction		148.1		168.4	132.5
Allowance for Borrowed Funds Used During Construction		66		88.7	73.6
Jointly-owned Electric Facilities
Utility Plant in Service		2,916.7		3,019.3
Construction Work in Progress		14.1		19.1
Accumulated Depreciation		1,109.7		1,051.9
Asset Impairments and Other Related Charges		0		156.4	70.6
Property, Plant and Equipment (Textuals)
Asset Retirement Obligations (ARO) Liability for Nuclear Decommissioning of the Cook Plant		1,800		1,730
AEP Texas Inc. [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		0		351.7
Property, Plant and Equipment, Transmission		5,279.6		4,466.5
Property, Plant and Equipment, Distribution		4,580.8		4,215.2
Property, Plant and Equipment, Other		868.4		805.9
Property, Plant and Equipment, Construction Work in Progress		614.1		763.9
Accumulated Depreciation		1,529.3		1,758.1
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		9,813.6		8,845.1
Asset Retirement Obligations (ARO)
Beginning Balance	[2],[3]	29.1		27.9
Accretion Expense	[2],[3]	0.8		1.3
Liabilities Incurred	[2],[3]	0		0
Liabilities Settled	[2],[3]	(8.5)		(0.2)
Revisions in Cash Flow Estimates	[2],[3],[5]	(16.8)		0.1
Ending Balance	[2],[3]	4.6		29.1	27.9
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction		19.4		15.2	20
Allowance for Borrowed Funds Used During Construction		$ 12.5		20	18.4
Jointly-owned Electric Facilities
Percent of Ownership		54.69%
Asset Impairments and Other Related Charges		$ 0		32.5	0
AEP Transmission Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Transmission		9,593.5		8,137.9
Property, Plant and Equipment, Other		329.5		269.6
Property, Plant and Equipment, Construction Work in Progress		1,422.6		1,485.7
Accumulated Depreciation		572.8		402.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		10,772.8		9,490.9
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction		74		84.3	70.6
Allowance for Borrowed Funds Used During Construction		25.5		32.2	26.1
Appalachian Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		6,633.7		6,563.7
Property, Plant and Equipment, Transmission		3,900.5		3,584.1
Property, Plant and Equipment, Distribution		4,464.3		4,201.7
Property, Plant and Equipment, Other		627.2		571.3
Property, Plant and Equipment, Construction Work in Progress		484.6		593.4
Accumulated Depreciation		4,716.2		4,432.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		11,394.1		11,081.9
Asset Retirement Obligations (ARO)
Beginning Balance	[2],[3]	111.1		116.1
Accretion Expense	[2],[3]	8.9		5.9
Liabilities Incurred	[2],[3]	0		0
Liabilities Settled	[2],[3]	(7.8)		(17.6)
Revisions in Cash Flow Estimates	[2],[3],[5]	200.9		6.7
Ending Balance	[2],[3]	313.1		111.1	116.1
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction		14.6		16.6	13.2
Allowance for Borrowed Funds Used During Construction		7.9		9.3	8.4
Jointly-owned Electric Facilities
Asset Impairments and Other Related Charges		0		92.9	0
Indiana Michigan Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		5,264.7		5,099.7
Property, Plant and Equipment, Transmission		1,696.4		1,641.8
Property, Plant and Equipment, Distribution		2,594.6		2,437.6
Property, Plant and Equipment, Other		686.7		632.6
Property, Plant and Equipment, Construction Work in Progress		362.4		382.3
Accumulated Depreciation		3,552.5		3,294.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		7,052.3		6,899.7
Asset Retirement Obligations (ARO)
Beginning Balance	[2],[3],[4]	1,748.6		1,681.3
Accretion Expense	[2],[3],[4]	70.2		67.4
Liabilities Incurred	[2],[3],[4]	0.1		0
Liabilities Settled	[2],[3],[4]	(0.2)		(0.2)
Revisions in Cash Flow Estimates	[2],[3],[4],[5]	(4.9)		0.1
Ending Balance	[2],[3],[4]	1,813.8		1,748.6	1,681.3
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction		11.5		19.4	11.9
Allowance for Borrowed Funds Used During Construction		5.7		8.9	7.4
Property, Plant and Equipment (Textuals)
Asset Retirement Obligations (ARO) Liability for Nuclear Decommissioning of the Cook Plant		1,800		1,730
Fair Value of Legally Restricted Assets		2,980		2,650
Ohio Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Transmission		2,831.9		2,686.3
Property, Plant and Equipment, Distribution		5,708.3		5,323.5
Property, Plant and Equipment, Other		899.6		765.8
Property, Plant and Equipment, Construction Work in Progress		362.3		394.4
Accumulated Depreciation		2,350		2,263
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		7,452.1		6,907
Asset Retirement Obligations (ARO)
Beginning Balance	[2]	1.8		1.8
Accretion Expense	[2]	0.1		0.1
Liabilities Incurred	[2]	0		0
Liabilities Settled	[2]	0		(0.3)
Revisions in Cash Flow Estimates	[2],[5]	0		0.2
Ending Balance	[2]	1.9		1.8	1.8
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction		12.5		18.2	9.8
Allowance for Borrowed Funds Used During Construction		6.2		6.7	5.8
Public Service Co Of Oklahoma [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		1,480.7		1,574.6
Property, Plant and Equipment, Transmission		1,069.9		948.5
Property, Plant and Equipment, Distribution		2,853		2,684.8
Property, Plant and Equipment, Other		393.3		342.1
Property, Plant and Equipment, Construction Work in Progress		128.7		133.4
Accumulated Depreciation		1,605.6		1,580.1
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		4,320		4,103.3
Asset Retirement Obligations (ARO)
Beginning Balance	[2],[3]	52.2		46.9
Accretion Expense	[2],[3]	3.1		3.1
Liabilities Incurred	[2],[3]	0		0
Liabilities Settled	[2],[3]	(3.1)		(0.4)
Revisions in Cash Flow Estimates	[2],[3],[5]	(4.8)		2.6
Ending Balance	[2],[3]	47.4		52.2	46.9
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction		4		2.7	0.4
Allowance for Borrowed Funds Used During Construction		2		1.9	0.9
Southwestern Electric Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		4,681.4		4,691.4
Property, Plant and Equipment, Transmission		2,165.7		2,056.5
Property, Plant and Equipment, Distribution		2,382.5		2,270.7
Property, Plant and Equipment, Other		788.8		733.4
Property, Plant and Equipment, Construction Work in Progress		228.3		216.9
Accumulated Depreciation		3,158.5		2,873.7
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		7,088.2		7,095.2
Asset Retirement Obligations (ARO)
Beginning Balance	[1],[2],[3]	212.2		206.8
Accretion Expense	[1],[2],[3]	10.7		10.3
Liabilities Incurred	[1],[2],[3]	0		0
Liabilities Settled	[1],[2],[3]	(10.9)		(11.8)
Revisions in Cash Flow Estimates	[1],[2],[3],[5]	10.1		6.9
Ending Balance	[1],[2],[3]	222.1		212.2	206.8
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization
Allowance for Equity Funds Used During Construction		7.7		6.8	6
Allowance for Borrowed Funds Used During Construction		3.9		4	$ 4.8
Jointly-owned Electric Facilities
Utility Plant in Service		2,916.7		2,912.7
Construction Work in Progress		14.1		19
Accumulated Depreciation		1,109.7		$ 960.2
Southwestern Electric Power Co [Member] | Ash Pond [Member]
Asset Retirement Obligations (ARO)
Revisions in Cash Flow Estimates		$ (18)
Dolet Hills Generating Station (Unit No. 1) [Member] | Public Utilities, Inventory, Lignite [Member]
Jointly-owned Electric Facilities
Percent of Ownership	[6]	40.20%		40.20%
Utility Plant in Service	[6]	$ 342.4		$ 337.3
Construction Work in Progress	[6]	4.6		6.2
Accumulated Depreciation	[6]	$ 295.4		$ 216.5
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	[6]	40.20%		40.20%
Utility Plant in Service	[6]	$ 342.4		$ 337.3
Construction Work in Progress	[6]	4.6		6.2
Accumulated Depreciation	[6]	$ 295.4		$ 216.5
Flint Creek Generating Station (Unit No. 1) [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership	[7]	50.00%		50.00%
Utility Plant in Service	[7]	$ 377.2		$ 374.3
Construction Work in Progress	[7]	3		3.4
Accumulated Depreciation	[7]	$ 116		$ 101.1
Flint Creek Generating Station (Unit No. 1) [Member] | Southwestern Electric Power Co [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership	[7]	50.00%		50.00%
Utility Plant in Service	[7]	$ 377.2		$ 374.3
Construction Work in Progress	[7]	3		3.4
Accumulated Depreciation	[7]	$ 116		$ 101.1
Pirkey Generating Station (Unit No. 1) [Member] | Public Utilities, Inventory, Lignite [Member]
Jointly-owned Electric Facilities
Percent of Ownership	[7]	85.90%		85.90%
Utility Plant in Service	[7]	$ 602.8		$ 607.8
Construction Work in Progress	[7]	3.7		7.7
Accumulated Depreciation	[7]	$ 441		$ 416.8
Pirkey Generating Station (Unit No. 1) [Member] | Southwestern Electric Power Co [Member] | Public Utilities, Inventory, Lignite [Member]
Jointly-owned Electric Facilities
Percent of Ownership	[7]	85.90%		85.90%
Utility Plant in Service	[7]	$ 602.8		$ 607.8
Construction Work in Progress	[7]	3.7		7.7
Accumulated Depreciation	[7]	$ 441		$ 416.8
Oklaunion Generating Station (Unit No. 1) [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership	[8],[9]	70.30%		70.30%
Utility Plant in Service	[8],[9]	$ 0		$ 106.6
Construction Work in Progress	[8],[9]	0		0.1
Accumulated Depreciation	[8],[9]	$ 0		$ 91.7
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	[8],[9]	54.70%		54.70%
Utility Plant in Service	[8],[9]	$ 0		$ 351.7
Construction Work in Progress	[8],[9]	0		0
Accumulated Depreciation	[8],[9]	$ 0		$ 291.9
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	[8],[9]	15.60%		15.60%
Utility Plant in Service	[8],[9]	$ 0		$ 106.6
Construction Work in Progress	[8],[9]	0		0.1
Accumulated Depreciation	[8],[9]	$ 0		$ 91.7
Turk Generating Plant [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership		73.30%	[7]	73.30%
Utility Plant in Service	[7]	$ 1,594.3		$ 1,593.3
Construction Work in Progress	[7]	2.8		1.7
Accumulated Depreciation	[7]	$ 257.3		$ 225.8
Turk Generating Plant [Member] | Southwestern Electric Power Co [Member] | Coal [Member]
Jointly-owned Electric Facilities
Percent of Ownership	[7]	73.30%		73.30%
Utility Plant in Service	[7]	$ 1,594.3		$ 1,593.3
Construction Work in Progress	[7]	2.8		1.7
Accumulated Depreciation	[7]	$ 257.3		$ 225.8
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	[10],[11],[12]	50.00%		50.00%
Utility Plant in Service	[10],[11],[12]	$ 1,228.5		$ 1,114.2
Construction Work in Progress	[10],[11],[12]	19.6		105.5
Accumulated Depreciation	[10],[11],[12]	$ 677.3		586.2
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	[13]	$ 21,587.8		21,323.5
Property, Plant and Equipment, Transmission		27,841.5		24,763.4
Property, Plant and Equipment, Distribution		23,972.1		22,440.8
Property, Plant and Equipment, Other		4,852.4		4,369.6
Property, Plant and Equipment, Construction Work in Progress	[13]	3,815		4,261.2
Accumulated Depreciation		20,094.2		18,778.1
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 61,974.6		$ 58,380.4
Regulated Operation [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation		132 years		132 years	132 years
Depreciable Life Ranges - Transmission		75 years		81 years	81 years
Depreciable Life Ranges - Distribution		78 years		78 years	78 years
Depreciable Life Ranges - Other		75 years		75 years	75 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	7 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		6.30%		5.50%	4.00%
Regulated Operation [Member] | Generation [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.70%		2.50%	2.40%
Regulated Operation [Member] | Transmission [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.60%		2.60%	2.70%
Regulated Operation [Member] | Transmission [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.00%		1.80%	1.60%
Regulated Operation [Member] | Distribution [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		3.70%		3.70%	3.60%
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		11.30%		9.50%	9.80%
Regulated Operation [Member] | Other Property Class [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.80%		2.60%	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		5,279.6		4,466.5
Property, Plant and Equipment, Distribution		4,580.8		4,215.2
Property, Plant and Equipment, Other		866		803.4
Property, Plant and Equipment, Construction Work in Progress		614.1		763.9
Accumulated Depreciation		1,528.1		1,465
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 9,812.4		$ 8,784
Regulated Operation [Member] | AEP Texas Inc. [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Transmission		75 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		50 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		2.00%		1.80%	1.70%
Regulated Operation [Member] | AEP Texas Inc. [Member] | Distribution [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		3.10%		3.50%	3.60%
Regulated Operation [Member] | AEP Texas Inc. [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		6.10%		6.30%	6.00%
Regulated Operation [Member] | AEP Transmission Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		$ 0		$ 0
Property, Plant and Equipment, Transmission		9,593.5		8,137.9
Property, Plant and Equipment, Distribution		0		0
Property, Plant and Equipment, Other		328.8		268.2
Property, Plant and Equipment, Construction Work in Progress		1,422.6		1,485.7
Accumulated Depreciation		572.8		402.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 10,772.1		$ 9,489.5
Regulated Operation [Member] | AEP Transmission Co [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Transmission		75 years		75 years	75 years
Depreciable Life Ranges - Other		64 years		64 years	64 years
Regulated Operation [Member] | AEP Transmission Co [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Transmission		24 years		24 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		2.40%		2.00%	1.90%
Regulated Operation [Member] | AEP Transmission Co [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		6.30%		5.80%	5.60%
Regulated Operation [Member] | Appalachian Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		$ 6,633.7		$ 6,563.7
Property, Plant and Equipment, Transmission		3,900.5		3,584.1
Property, Plant and Equipment, Distribution		4,464.3		4,201.7
Property, Plant and Equipment, Other		598		542
Property, Plant and Equipment, Construction Work in Progress		484.6		593.4
Accumulated Depreciation		4,711		4,425.6
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 11,370.1		$ 11,059.3
Regulated Operation [Member] | Appalachian Power Co [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation		118 years		118 years	112 years
Depreciable Life Ranges - Transmission		75 years		71 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		12 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		3.30%		3.20%	3.10%
Regulated Operation [Member] | Appalachian Power Co [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.20%		1.80%	1.60%
Regulated Operation [Member] | Appalachian Power Co [Member] | Distribution [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		3.70%		3.70%	3.60%
Regulated Operation [Member] | Appalachian Power Co [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		7.80%		7.20%	7.40%
Regulated Operation [Member] | Indiana Michigan Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		$ 5,264.7		$ 5,099.7
Property, Plant and Equipment, Transmission		1,696.4		1,641.8
Property, Plant and Equipment, Distribution		2,594.6		2,437.6
Property, Plant and Equipment, Other		644.6		590.9
Property, Plant and Equipment, Construction Work in Progress		362.4		382.3
Accumulated Depreciation		3,538.6		3,281.4
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 7,024.1		$ 6,870.9
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		70 years		73 years	73 years
Depreciable Life Ranges - Distribution		71 years		75 years	75 years
Depreciable Life Ranges - Other		51 years		50 years	50 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		45 years		50 years	50 years
Depreciable Life Ranges - Distribution		14 years		9 years	9 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		4.60%		4.00%	3.40%
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.30%		1.90%	1.80%
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Distribution [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		3.40%		3.40%	3.10%
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		10.20%		9.40%	8.90%
Regulated Operation [Member] | Ohio Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		$ 0		$ 0
Property, Plant and Equipment, Transmission		2,831.9		2,686.3
Property, Plant and Equipment, Distribution		5,708.3		5,323.5
Property, Plant and Equipment, Other		888.5		754.7
Property, Plant and Equipment, Construction Work in Progress		362.3		394.4
Accumulated Depreciation		2,348.8		2,261.7
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 7,442.2		$ 6,897.2
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	65 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	14 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%		3.10%	3.00%
Regulated Operation [Member] | Ohio Power Co [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		5.00%		4.90%	6.30%
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation		$ 1,480.7		$ 1,574.6
Property, Plant and Equipment, Transmission		1,069.9		948.5
Property, Plant and Equipment, Distribution		2,853		2,684.8
Property, Plant and Equipment, Other		388.1		337.2
Property, Plant and Equipment, Construction Work in Progress		128.7		133.4
Accumulated Depreciation		1,607.3		1,579.9
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 4,313.1		$ 4,098.6
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation		75 years		75 years	75 years
Depreciable Life Ranges - Transmission		75 years		75 years	75 years
Depreciable Life Ranges - Distribution		78 years		78 years	78 years
Depreciable Life Ranges - Other		64 years		64 years	64 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	15 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		3.10%		2.90%	2.90%
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.20%		2.40%	2.30%
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Distribution [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.90%		2.90%	2.90%
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		5.70%		5.60%	6.30%
Regulated Operation [Member] | Southwestern Electric Power Co [Member]
Depreciation, Depletion and Amortization
Property, Plant and Equipment, Generation	[13]	$ 4,681.4		$ 4,691.4
Property, Plant and Equipment, Transmission		2,165.7		2,056.5
Property, Plant and Equipment, Distribution		2,382.5		2,270.7
Property, Plant and Equipment, Other		564.5		520.6
Property, Plant and Equipment, Construction Work in Progress	[13]	228.3		210.1
Accumulated Depreciation		3,032		2,766.2
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 6,990.4		$ 6,983.1
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation		65 years		70 years	70 years
Depreciable Life Ranges - Transmission		73 years		73 years	73 years
Depreciable Life Ranges - Distribution		67 years		70 years	70 years
Depreciable Life Ranges - Other		52 years		55 years	55 years
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation		35 years		40 years	40 years
Depreciable Life Ranges - Transmission		47 years		50 years	50 years
Depreciable Life Ranges - Distribution		15 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		2.70%		2.50%	2.40%
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.30%		2.40%	2.20%
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		8.50%		7.60%	8.00%
Unregulated Operation [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 1,927		$ 1,757.7
Depreciable Life Ranges - Transmission					40 years
Depreciable Life Ranges - Distribution				40 years	40 years
Unregulated Operation [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Depreciable Life Ranges - Generation		59 years		59 years	59 years
Depreciable Life Ranges - Transmission		40 years		40 years
Depreciable Life Ranges - Other	[14]	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		30 years
Depreciable Life Ranges - Other	[14]	5 years		5 years	5 years
Unregulated Operation [Member] | Generation [Member] | Maximum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		4.00%		21.20%	22.30%
Unregulated Operation [Member] | Generation [Member] | Minimum [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		3.60%		3.20%	3.40%
Unregulated Operation [Member] | Transmission [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		2.50%		2.50%	2.40%
Unregulated Operation [Member] | Distribution [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate				2.30%	2.30%
Unregulated Operation [Member] | Other Property Class [Member]
Depreciation, Depletion and Amortization
Annual Composite Depreciation Rate		16.10%		17.60%	16.30%
Unregulated Operation [Member] | AEP Texas Inc. [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 1.2		$ 61.1
Unregulated Operation [Member] | AEP Transmission Co [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		0.7		1.4
Unregulated Operation [Member] | Appalachian Power Co [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		24		22.6
Unregulated Operation [Member] | Indiana Michigan Power Co [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		28.2		28.8
Unregulated Operation [Member] | Ohio Power Co [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		9.9		9.8
Unregulated Operation [Member] | Public Service Co Of Oklahoma [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		6.9		4.7
Unregulated Operation [Member] | Southwestern Electric Power Co [Member]
Depreciation, Depletion and Amortization
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		$ 97.8		112.1
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
Oklaunion Generating Station [Member] | AEP Texas Inc. [Member]
Asset Retirement Obligations (ARO)
Revisions in Cash Flow Estimates		$ (17)
Oklaunion Generating Station [Member] | Public Service Co Of Oklahoma [Member]
Asset Retirement Obligations (ARO)
Revisions in Cash Flow Estimates		(5)
Dolet Hills Power Station [Member] | Southwestern Electric Power Co [Member]
Asset Retirement Obligations (ARO)
Revisions in Cash Flow Estimates		21
Glen Lyn Station [Member] | Appalachian Power Co [Member]
Asset Retirement Obligations (ARO)
Revisions in Cash Flow Estimates		199
Generation and Marketing [Member]
Depreciation, Depletion and Amortization
Accumulated Depreciation		166.1		99
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		1,744.1		1,551.8
Jointly-owned Electric Facilities
Asset Impairments and Other Related Charges				$ 31	$ 47.7
Generation and Marketing [Member] | Conesville Generating Station [Member]
Asset Retirement Obligations (ARO)
Liabilities Settled		$ (106)
[1]	Includes ARO related to Sabine and DHLC.
[2]	Includes ARO related to asbestos removal.
[3]	Includes ARO related to ash disposal facilities.
[4]	Includes ARO related to nuclear decommissioning costs for the Cook Plant of $1.80 billion and $1.73 billion as of December 31, 2020 and 2019, respectively.
[5]	Unless discussed above, primarily related to ash ponds, landfills and mine reclamation, generally due to changes in estimated closure area, volumes and/or unit costs.
[6]	Operated by CLECO, a nonaffiliated company.
[7]	Operated by SWEPCo.
[8]	Oklaunion Power Station was retired in September 2020 and sold to a nonaffiliated third-party in October 2020. See the “Dispositions” section of Note 7 for additional information.
[9]	Operated by PSO, which owned 15.6%. Also was jointly-owned (54.7%) by AEP Texas and various nonaffiliated companies.
[10]	AEGCo owns 50% of Unit 1 with I&M and 50% of capital additions for Unit 2.
[11]	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 for additional information.
[12]	Operated by I&M.
[13]	AEP and SWEPCo’s regulated generation and regulated CWIP include amounts related to SWEPCo’s Arkansas jurisdictional share of the Turk Plant.
[14]	SWEPCo’s nonregulated property, plant and equipment is depreciated using the straight-line method over a range of 3 to 20 years.NA Not applicable.

Revenue from Contracts with C_3

Revenue from Contracts with Customers (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Disaggregation of Revenue
Revenue from Contracts with Customers		$ 14,918.5		$ 15,561.4		$ 16,195.7
Revenue, Performance Obligation
Fixed Performance Obligations		1,610.7
Revenues		14,918.5		15,561.4		16,195.7
Revenue Textuals
Revenue from Related Parties		0		0		0
Redemption of Noncontrolling Interest		(100.2)		0		0
2021 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		1,122.9
2022-2023 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		164.1
2024-2025 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		162.2
After 2025 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		161.5
Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		11,364		11,851.9		12,327.8	[1]
Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		5,693.7		5,713.6		5,941.2
Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		3,064.8		3,308.2		3,435.1
Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		2,407.4		2,607.2		2,725.3
Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		198.1		222.9		226.2
Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		3,209.7		3,444.2		3,435.7
Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		720.2		1,062.4		1,316.2
Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,051.8	[2]	979.4	[3]	766.5	[4]
Renewable Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		59.3	[5]	57.3	[6]	50.8	[7]
Retail, Trading and Marketing Revenue [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,378.4	[8]	1,345.1	[9]	1,302.2	[10]
Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		289.6	[5]	316.7	[6]	453	[7]
Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		14,863.3		15,612.8		16,216.5
Alternative and Other [Member]
Revenue, Performance Obligation
Revenues		55.2		(51.4)		(20.8)
Alternative [Member]
Revenue, Performance Obligation
Revenues		(6.3)	[5]	(113.1)	[6]	(45.8)	[7]
Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		305.6		274.9		268.6
Revenue, Performance Obligation
Revenues		61.5	[5]	61.7	[6]	25	[7]
AEP Texas Inc. [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,528		1,551.6		1,493
Revenue, Performance Obligation
Fixed Performance Obligations		465.4
Revenues		1,618.9		1,709.3		1,595.3
Current Assets
Affiliated Companies - Contracts with Customers		5.1		10.1
Revenue Textuals
Revenue from Related Parties		90.8		160.5		105.2
AEP Texas Inc. [Member] | 2021 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		465.4
AEP Texas Inc. [Member] | 2022-2023 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		0
AEP Texas Inc. [Member] | 2024-2025 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		0
AEP Texas Inc. [Member] | After 2025 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		0
AEP Texas Inc. [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,079.9		1,142.3		1,151	[11]
AEP Texas Inc. [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		563.6		571.5		578.9
AEP Texas Inc. [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		366.7		411.5		414.7
AEP Texas Inc. [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		120.1		129.4		128
AEP Texas Inc. [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		29.5		29.9		29.4
AEP Texas Inc. [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		399.9		379.2		313.4
AEP Texas Inc. [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0	[12]	0	[13]	0	[14]
AEP Texas Inc. [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		399.9	[15]	379.2	[16]	313.4	[17]
AEP Texas Inc. [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		48.2	[18]	30.1	[19]	28.6	[20]
AEP Texas Inc. [Member] | Alternative and Other [Member]
Revenue, Performance Obligation
Revenues		90.9		157.7		102.3
AEP Texas Inc. [Member] | Alternative [Member]
Revenue, Performance Obligation
Revenues		3.4	[21]	0.6	[22]	(1.3)	[23]
AEP Texas Inc. [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		3.2		2.9		3.8
Revenue, Performance Obligation
Revenues		87.5	[21]	157.1	[22]	103.6	[23]
AEP Transmission Co [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,232.7		1,042.1		832
Revenue, Performance Obligation
Fixed Performance Obligations		1,319.5
Revenues		1,145.7		1,021.4		776.1
Current Assets
Affiliated Companies - Contracts with Customers		81.2		66.1
Revenue Textuals
Revenue from Related Parties		896.3		806.7		598.9
AEP Transmission Co [Member] | Short-term Contract with Customer [Member]
Current Assets
Affiliated Companies - Contracts with Customers		81		65.9
AEP Transmission Co [Member] | 2021 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		1,319.5
AEP Transmission Co [Member] | 2022-2023 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		0
AEP Transmission Co [Member] | 2024-2025 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		0
AEP Transmission Co [Member] | After 2025 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		0
AEP Transmission Co [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0	[11]
AEP Transmission Co [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
AEP Transmission Co [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
AEP Transmission Co [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
AEP Transmission Co [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
AEP Transmission Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,210.3		1,025.5		816.9
AEP Transmission Co [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0	[12]	0	[13]	0	[14]
AEP Transmission Co [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,210.3	[15]	1,025.5	[16]	816.9	[17]
Revenue Textuals
Revenue from Related Parties		952		782		646
AEP Transmission Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		22.4	[18]	16.6	[19]	15.1	[20]
AEP Transmission Co [Member] | Alternative and Other [Member]
Revenue, Performance Obligation
Revenues		(87)		(20.7)		(55.9)
AEP Transmission Co [Member] | Alternative [Member]
Revenue, Performance Obligation
Revenues		(87)	[21]	(20.7)	[22]	(55.9)	[23]
AEP Transmission Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0.6		0.1		0.2
Revenue, Performance Obligation
Revenues		0	[21]	0	[22]	0	[23]
Appalachian Power Co [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		2,809.2		2,911.1		2,993.2
Revenue, Performance Obligation
Fixed Performance Obligations		240.5
Revenues		2,796.2		2,924.7		2,967.5
Current Assets
Affiliated Companies - Contracts with Customers		64.3		64.3
Revenue Textuals
Revenue from Related Parties		174.7		205.3		181.4
Appalachian Power Co [Member] | Short-term Contract with Customer [Member]
Current Assets
Affiliated Companies - Contracts with Customers		52.7		47.3
Appalachian Power Co [Member] | 2021 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		173.4
Appalachian Power Co [Member] | 2022-2023 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		32.3
Appalachian Power Co [Member] | 2024-2025 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		23.2
Appalachian Power Co [Member] | After 2025 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		11.6
Appalachian Power Co [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		2,388.7		2,494.2		2,604.8	[11]
Appalachian Power Co [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,250.6		1,266.9		1,342.7
Appalachian Power Co [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		517		559.9		580.4
Appalachian Power Co [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		553.5		592.2		604.3
Appalachian Power Co [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		67.6		75.2		77.4
Appalachian Power Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		361		355.1		333.1
Appalachian Power Co [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		230.2	[12]	251.5	[13]	250.4	[14]
Revenue Textuals
Revenue from Related Parties		112		129		134
Appalachian Power Co [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		130.8	[15]	103.6	[16]	82.7	[17]
Appalachian Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		59.5	[18]	61.8	[19]	55.3	[20]
Appalachian Power Co [Member] | Alternative and Other [Member]
Revenue, Performance Obligation
Revenues		(13)		13.6		(25.7)
Appalachian Power Co [Member] | Alternative [Member]
Revenue, Performance Obligation
Revenues		(13)	[21]	13.6	[22]	(23.8)	[23]
Appalachian Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		10.6		11.2		9
Revenue, Performance Obligation
Revenues		0	[21]	0	[22]	(1.9)	[23]
Indiana Michigan Power Co [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		2,236		2,308.1		2,381
Revenue, Performance Obligation
Fixed Performance Obligations		57.2
Revenues		2,241.8		2,306.7		2,370.7
Current Assets
Affiliated Companies - Contracts with Customers		51.3		53.7
Revenue Textuals
Revenue from Related Parties		10.5		10.5		22.1
Indiana Michigan Power Co [Member] | Short-term Contract with Customer [Member]
Current Assets
Affiliated Companies - Contracts with Customers		34.8		37.1
Indiana Michigan Power Co [Member] | 2021 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		35.1
Indiana Michigan Power Co [Member] | 2022-2023 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		8.8
Indiana Michigan Power Co [Member] | 2024-2025 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		8.8
Indiana Michigan Power Co [Member] | After 2025 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		4.5
Indiana Michigan Power Co [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,847.4		1,782.2		1,787.8	[11]
Indiana Michigan Power Co [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		794.1		730		730
Indiana Michigan Power Co [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		499.3		494.2		485
Indiana Michigan Power Co [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		547.4		550.7		565.6
Indiana Michigan Power Co [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		6.6		7.3		7.2
Indiana Michigan Power Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		303.6		427.5		493.6
Indiana Michigan Power Co [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		274.6	[12]	402.4	[13]	470.5	[14]
Indiana Michigan Power Co [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		29	[15]	25.1	[16]	23.1	[17]
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		85	[18]	98.4	[19]	99.6	[20]
Indiana Michigan Power Co [Member] | Alternative and Other [Member]
Revenue, Performance Obligation
Revenues		5.8		(1.4)		(10.3)
Indiana Michigan Power Co [Member] | Alternative [Member]
Revenue, Performance Obligation
Revenues		5.8	[21]	(1.4)	[22]	(2.1)	[23]
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		5.2		10.7		12.6
Revenue, Performance Obligation
Revenues		0	[21]	0	[22]	(8.2)	[23]
Revenue Textuals
Revenue from Related Parties		69		73		70
Ohio Power Co [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		2,665		2,748.8		3,079.9
Revenue, Performance Obligation
Fixed Performance Obligations		68.2
Revenues		2,749.1		2,797.6		3,063.4
Current Assets
Affiliated Companies - Contracts with Customers		65.1		59.3
Revenue Textuals
Revenue from Related Parties		41.5		27.3		21
Ohio Power Co [Member] | Short-term Contract with Customer [Member]
Current Assets
Affiliated Companies - Contracts with Customers		45.9		33.9
Ohio Power Co [Member] | 2021 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		68.1
Ohio Power Co [Member] | 2022-2023 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		0
Ohio Power Co [Member] | 2024-2025 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		0
Ohio Power Co [Member] | After 2025 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		0.1
Ohio Power Co [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		2,488.5		2,553.5		2,845.3	[11]
Ohio Power Co [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,523.4		1,502		1,611.6
Ohio Power Co [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		682		738.5		835.6
Ohio Power Co [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		270		299.9		385.2
Ohio Power Co [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		13.1		13.1		12.9
Ohio Power Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		67		56		58.5
Ohio Power Co [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0	[12]	0	[13]	0	[14]
Ohio Power Co [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		67	[15]	56	[16]	58.5	[17]
Ohio Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		109.5	[18]	139.3	[19]	176.1	[20]
Ohio Power Co [Member] | Alternative and Other [Member]
Revenue, Performance Obligation
Revenues		84.1		48.8		(16.5)
Ohio Power Co [Member] | Alternative [Member]
Revenue, Performance Obligation
Revenues		66.6	[21]	31.7	[22]	(20.8)	[23]
Ohio Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		9		10.8		8.6
Revenue, Performance Obligation
Revenues		17.5	[21]	17.1	[22]	4.3	[23]
Public Service Co Of Oklahoma [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,263.9		1,512.8		1,536.4
Revenue, Performance Obligation
Fixed Performance Obligations		14.8
Revenues		1,266.1		1,481.8		1,547.3
Current Assets
Affiliated Companies - Contracts with Customers		15.6		20.6
Revenue Textuals
Revenue from Related Parties		5.2		6.1		5.4
Public Service Co Of Oklahoma [Member] | Short-term Contract with Customer [Member]
Current Assets
Affiliated Companies - Contracts with Customers		7.8		9.7
Public Service Co Of Oklahoma [Member] | 2021 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		14.8
Public Service Co Of Oklahoma [Member] | 2022-2023 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		0
Public Service Co Of Oklahoma [Member] | 2024-2025 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		0
Public Service Co Of Oklahoma [Member] | After 2025 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		0
Public Service Co Of Oklahoma [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,186.6		1,423.8		1,440.8	[11]
Public Service Co Of Oklahoma [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		579.4		650.2		659
Public Service Co Of Oklahoma [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		320.1		388.5		394.2
Public Service Co Of Oklahoma [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		221.1		303.5		304
Public Service Co Of Oklahoma [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		66		81.6		83.6
Public Service Co Of Oklahoma [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		42.6		67		76.5
Public Service Co Of Oklahoma [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		15.1	[12]	39.5	[13]	36.3	[14]
Public Service Co Of Oklahoma [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		27.5	[15]	27.5	[16]	40.2	[17]
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		34.7	[18]	22	[19]	19.1	[20]
Public Service Co Of Oklahoma [Member] | Alternative and Other [Member]
Revenue, Performance Obligation
Revenues		2.2		(31)		10.9
Public Service Co Of Oklahoma [Member] | Alternative [Member]
Revenue, Performance Obligation
Revenues		2.2	[21]	(31)	[22]	10.9	[23]
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		14.8		6.1		4.3
Revenue, Performance Obligation
Revenues		0	[21]	0	[22]	0	[23]
Southwestern Electric Power Co [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,735.3		1,799.2		1,817
Revenue, Performance Obligation
Fixed Performance Obligations		41.6
Revenues		1,738.5		1,750.9		1,821.9
Current Assets
Affiliated Companies - Contracts with Customers		25.1		34.5
Revenue Textuals
Revenue from Related Parties		41		36.9		35.1
Southwestern Electric Power Co [Member] | Short-term Contract with Customer [Member]
Current Assets
Affiliated Companies - Contracts with Customers		11.2		17.6
Southwestern Electric Power Co [Member] | 2021 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		41.6
Southwestern Electric Power Co [Member] | 2022-2023 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		0
Southwestern Electric Power Co [Member] | 2024-2025 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		0
Southwestern Electric Power Co [Member] | After 2025 [Member]
Revenue, Performance Obligation
Fixed Performance Obligations		0
Southwestern Electric Power Co [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,435.4		1,471.7		1,467.8	[11]
Southwestern Electric Power Co [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		630.8		638.6		641.6
Southwestern Electric Power Co [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		466.7		485.4		483.9
Southwestern Electric Power Co [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		328.8		338.7		333.7
Southwestern Electric Power Co [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		9.1		9		8.6
Southwestern Electric Power Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		273.2		301.4		325.2
Southwestern Electric Power Co [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		162	[12]	194.7	[13]	216.8	[14]
Southwestern Electric Power Co [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		111.2	[15]	106.7	[16]	108.4	[17]
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		26.7	[18]	26.1	[19]	24	[20]
Southwestern Electric Power Co [Member] | Alternative and Other [Member]
Revenue, Performance Obligation
Revenues		3.2		(48.3)		4.9
Southwestern Electric Power Co [Member] | Alternative [Member]
Revenue, Performance Obligation
Revenues		3.2	[21]	(48.3)	[22]	4.9	[23]
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		2.9		1.4		1.6
Revenue, Performance Obligation
Revenues		0	[21]	0	[22]	0	[23]
Consolidation Eliminations [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
Revenue, Performance Obligation
Revenues		(1,328)		(1,314.8)		(942.4)
Revenue Textuals
Revenue from Related Parties		(1,328)		(1,314.8)		(942.4)
Consolidation Eliminations [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		(0.7)		(0.9)		0	[1]
Consolidation Eliminations [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
Consolidation Eliminations [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
Consolidation Eliminations [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		(0.7)		(0.9)		0
Consolidation Eliminations [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
Consolidation Eliminations [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		(1,111.3)		(960.6)		(865.1)
Consolidation Eliminations [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		(7.3)	[24]
Consolidation Eliminations [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		(1,006.7)	[2]	(825)	[3]	(737.1)	[4]
Consolidation Eliminations [Member] | Renewable Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		(1.6)	[5]	0	[6]	0	[7]
Consolidation Eliminations [Member] | Retail, Trading and Marketing Revenue [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		(103)	[8]	(135.6)	[9]	(120.7)	[10]
Consolidation Eliminations [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		(148.6)	[5]	(147.1)	[6]	(32)	[7]
Consolidation Eliminations [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		(1,260.6)		(1,108.6)		(897.1)
Consolidation Eliminations [Member] | Alternative and Other [Member]
Revenue, Performance Obligation
Revenues		(67.4)		(206.2)		(45.3)
Consolidation Eliminations [Member] | Alternative [Member]
Revenue, Performance Obligation
Revenues		7.5	[5]	(66.9)	[6]	52.7	[7]
Consolidation Eliminations [Member] | Other Revenues [Member]
Revenue, Performance Obligation
Revenues		(74.9)	[5]	(139.3)	[6]	(98)	[7],[24]
Consolidation Eliminations [Member] | AEP Transmission Co [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
Revenue, Performance Obligation
Revenues		0		0		0
Revenue Textuals
Revenue from Related Parties		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, Performance Obligation
Revenues		8,879.4		9,367.1		9,645.5
Revenue Textuals
Revenue from Related Parties		126.2		121.4		88.8
Vertically Integrated Utilities [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		7,796.6		8,157.1		8,331.5	[1]
Vertically Integrated Utilities [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		3,606.8		3,643.7		3,751.8
Vertically Integrated Utilities [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		2,016.2		2,155.3		2,183.4
Vertically Integrated Utilities [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		2,018		2,179		2,212.8
Vertically Integrated Utilities [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		155.6		179.1		183.5
Vertically Integrated Utilities [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		922.8		1,099.7		1,182
Vertically Integrated Utilities [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		588.3		807.6		899.8
Vertically Integrated Utilities [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		334.5	[2]	292.1	[3]	282.2	[4]
Vertically Integrated Utilities [Member] | Renewable Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0	[5]	0	[6]	0	[7]
Vertically Integrated Utilities [Member] | Retail, Trading and Marketing Revenue [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0	[8]	0	[9]	0	[10]
Vertically Integrated Utilities [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		163.2	[5]	168.2	[6]	158.4	[7]
Vertically Integrated Utilities [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		8,882.6		9,425		9,671.9
Vertically Integrated Utilities [Member] | Alternative and Other [Member]
Revenue, Performance Obligation
Revenues		(3.2)		(57.9)		(26.4)
Vertically Integrated Utilities [Member] | Alternative [Member]
Revenue, Performance Obligation
Revenues		(3.2)	[5]	(57.9)	[6]	(15.9)	[7]
Vertically Integrated Utilities [Member] | Other Revenues [Member]
Revenue, Performance Obligation
Revenues		0	[5]	0	[6]	(10.5)	[7]
Transmission And Distribution Utilities [Member]
Revenue, Performance Obligation
Revenues		4,345.9		4,482.5		4,653.1
Revenue Textuals
Revenue from Related Parties		107.2		163.5		100.8
Transmission And Distribution Utilities [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		3,568.1		3,695.7		3,996.3	[1]
Transmission And Distribution Utilities [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		2,086.9		2,069.9		2,189.4
Transmission And Distribution Utilities [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,048.6		1,152.9		1,251.7
Transmission And Distribution Utilities [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		390.1		429.1		512.5
Transmission And Distribution Utilities [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		42.5		43.8		42.7
Transmission And Distribution Utilities [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		467		435.1		372.1
Transmission And Distribution Utilities [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
Transmission And Distribution Utilities [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		467	[2]	435.1	[3]	372.1	[4]
Transmission And Distribution Utilities [Member] | Renewable Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0	[5]	0	[6]	0	[7]
Transmission And Distribution Utilities [Member] | Retail, Trading and Marketing Revenue [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0	[8]	0	[9]	0	[10]
Transmission And Distribution Utilities [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		157.8	[5]	169.4	[6]	204.6	[7]
Transmission And Distribution Utilities [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		4,192.9		4,300.2		4,573
Transmission And Distribution Utilities [Member] | Alternative and Other [Member]
Revenue, Performance Obligation
Revenues		153		182.3		80.1
Transmission And Distribution Utilities [Member] | Alternative [Member]
Revenue, Performance Obligation
Revenues		70	[5]	32.3	[6]	(22.2)	[7]
Transmission And Distribution Utilities [Member] | Other Revenues [Member]
Revenue, Performance Obligation
Revenues		83	[5]	150	[6]	102.3	[7]
AEP Transmission Holdco [Member]
Revenue, Performance Obligation
Revenues		1,198.8		1,073.2		804.1
AEP Transmission Holdco [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0	[1]
AEP Transmission Holdco [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
AEP Transmission Holdco [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
AEP Transmission Holdco [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
AEP Transmission Holdco [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
AEP Transmission Holdco [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,257		1,077.2		849.3
AEP Transmission Holdco [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
AEP Transmission Holdco [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,257	[2]	1,077.2	[3]	849.3	[4]
Revenue Textuals
Revenue from Related Parties		965		794		643
AEP Transmission Holdco [Member] | Renewable Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0	[5]	0	[6]	0	[7]
AEP Transmission Holdco [Member] | Retail, Trading and Marketing Revenue [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0	[8]	0	[9]	0	[10]
AEP Transmission Holdco [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		22.4	[5]	16.6	[6]	15.2	[7]
AEP Transmission Holdco [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,279.4		1,093.8		864.5
AEP Transmission Holdco [Member] | Alternative and Other [Member]
Revenue, Performance Obligation
Revenues		(80.6)		(20.6)		(60.4)
AEP Transmission Holdco [Member] | Alternative [Member]
Revenue, Performance Obligation
Revenues		(80.6)	[5]	(20.6)	[6]	(60.4)	[7]
AEP Transmission Holdco [Member] | Other Revenues [Member]
Revenue, Performance Obligation
Revenues		0	[5]	0	[6]	0	[7]
Generation and Marketing [Member]
Revenue, Performance Obligation
Revenues		1,725.6		1,857.6		1,940.3
Revenue Textuals
Revenue from Related Parties		104.6		135.8		122.2
Generation and Marketing [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0	[1]
Generation and Marketing [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
Generation and Marketing [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
Generation and Marketing [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
Generation and Marketing [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
Generation and Marketing [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,679.7		1,792.8		1,897.4
Generation and Marketing [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		131.9		254.8		423.7
Generation and Marketing [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0	[2]	0	[3]	0	[4]
Generation and Marketing [Member] | Renewable Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		60.9	[5]	57.3	[6]	50.8	[7]
Generation and Marketing [Member] | Retail, Trading and Marketing Revenue [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,486.9	[8]	1,480.7	[9]	1,422.9	[10]
Revenue Textuals
Revenue from Related Parties		103		136		121
Generation and Marketing [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		2.3	[5]	4.9	[6]	20.6	[7]
Generation and Marketing [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		1,682		1,797.7		1,918
Generation and Marketing [Member] | Alternative and Other [Member]
Revenue, Performance Obligation
Revenues		43.6		59.9		22.3
Generation and Marketing [Member] | Alternative [Member]
Revenue, Performance Obligation
Revenues		0	[5]	0	[6]	0	[7]
Generation and Marketing [Member] | Other Revenues [Member]
Revenue, Performance Obligation
Revenues		43.6	[5]	59.9	[6]	22.3	[7]
Other Segments [Member]
Revenue, Performance Obligation
Revenues	[25]	96.8		95.8		95.1
Revenue Textuals
Revenue from Related Parties	[25]	88.6		81.1		75.1
Other Segments [Member] | Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0	[1]
Other Segments [Member] | Residential [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
Other Segments [Member] | Commercial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
Other Segments [Member] | Industrial [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
Other Segments [Member] | Other Retail [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
Other Segments [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		(5.5)		0		0
Other Segments [Member] | Wholesale Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0		0		0
Other Segments [Member] | Wholesale Transmission [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0	[2]	0	[3]	0	[4]
Other Segments [Member] | Renewable Generation [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		0	[5]	0	[6]	0	[7]
Other Segments [Member] | Retail, Trading and Marketing Revenue [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		(5.5)	[8]	0	[9]	0	[10]
Other Segments [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		92.5	[5]	104.7	[6]	86.2	[7]
Other Segments [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers		87		104.7		86.2
Other Segments [Member] | Alternative and Other [Member]
Revenue, Performance Obligation
Revenues		9.8		(8.9)		8.9
Other Segments [Member] | Alternative [Member]
Revenue, Performance Obligation
Revenues		0	[5]	0	[6]	0	[7]
Other Segments [Member] | Other Revenues [Member]
Disaggregation of Revenue
Revenue from Contracts with Customers	[25]	8.2		14.7		20
Revenue, Performance Obligation
Revenues		$ 9.8	[5]	$ (8.9)	[6]	8.9	[7]
Consolidation Eliminations [Member] | Other Revenues [Member]
Revenue Textuals
Revenue from Related Parties						$ 98
[1]	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.
[2]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $965 million. The remaining affiliated amounts were immaterial.
[3]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $794 million. The remaining affiliated amounts were immaterial.
[4]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $643 million. The remaining affiliated amounts were immaterial.
[5]	Amounts include affiliated and nonaffiliated revenues.
[6]	Amounts include affiliated and nonaffiliated revenues.
[7]	Amounts include affiliated and nonaffiliated revenues.
[8]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $103 million. The remaining affiliated amounts were immaterial.
[9]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $136 million. The remaining affiliated amounts were immaterial.
[10]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $121 million. The remaining affiliated amounts were immaterial.
[11]	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.
[12]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $112 million primarily relating to the PPA with KGPCo. The remaining affiliated amounts were immaterial.
[13]	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.
[14]	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.
[15]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEPTCo was $952 million. The remaining affiliated amounts were immaterial.
[16]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEPTCo was $782 million. The remaining affiliated amounts were immaterial.
[17]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEPTCo was $646 million. The remaining affiliated amounts were immaterial
[18]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $69 million primarily relating to barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial.
[19]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $73 million primarily relating to barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial.
[20]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $70 million primarily relating to barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial
[21]	Amounts include affiliated and nonaffiliated revenues.
[22]	Amounts include affiliated and nonaffiliated revenues.
[23]	Amounts include affiliated and nonaffiliated revenues.
[24]	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.
[25]	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.

Goodwill (Details)

Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
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

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event [Member] $ in Millions	2 Months Ended
	Feb. 25, 2021USD ($)
Public Service Co Of Oklahoma [Member]
Estimated Natural Gas Expenses Associated with February 2021 Severe Weather	$ 175
Estimated Electricity Purchases Associated with February 2021 Severe Weather	650
Total Estimated Natural Gas Expenses and Electricity Purchase Associated with February 2021 Severe Weather	825
Notification from SPP for Additional Collateral Requirements Related to February 2021 Severe Weather	868
Southwestern Electric Power Co [Member]
Estimated Natural Gas Expenses Associated with February 2021 Severe Weather	375
Estimated Electricity Purchases Associated with February 2021 Severe Weather	0
Total Estimated Natural Gas Expenses and Electricity Purchase Associated with February 2021 Severe Weather	375
Notification from SPP for Additional Collateral Requirements Related to February 2021 Severe Weather	868
Minimum [Member] | Appalachian Power Co [Member]
Total Estimated February 2021 Storm Restoration Expenditures	65
Minimum [Member] | Southwestern Electric Power Co [Member]
Total Estimated February 2021 Storm Restoration Expenditures	30
Minimum [Member] | Kentucky Power Co [Member]
Total Estimated February 2021 Storm Restoration Expenditures	75
Maximum [Member] | Appalachian Power Co [Member]
Total Estimated February 2021 Storm Restoration Expenditures	75
Maximum [Member] | Southwestern Electric Power Co [Member]
Total Estimated February 2021 Storm Restoration Expenditures	40
Maximum [Member] | Kentucky Power Co [Member]
Total Estimated February 2021 Storm Restoration Expenditures	$ 95