Appalachian Power 10-Q 6 May 20 2020 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2020	May 06, 2020
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 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 Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		495,583,133
Entity Central Index Key	0000004904
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
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 Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		100
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 Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Central Index Key	0001702494
Appalachian Power Co [Member]
Entity Information [Line Items]
Entity File Number	1-3457
Entity Registrant Name	APPALACHIAN POWER COMPANY
Entity Incorporation, State or Country Code	VA
Entity Tax Identification Number	54-0124790
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		13,499,500
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 Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		1,400,000
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 Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		27,952,473
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 Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		9,013,000
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 Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		7,536,640
Entity Central Index Key	0000092487
New York Stock Exchange | Common Stock [Member]
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, $6.50 par value
Trading Symbol	AEP
Security Exchange Name	NYSE
New York Stock Exchange | Preferred Stock [Member]
Entity Information [Line Items]
Title of 12(b) Security	6.125% Corporate Units
Trading Symbol	AEP PR B
Security Exchange Name	NYSE

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020		Mar. 31, 2019
Revenues
Revenue from Contracts with Customers	$ 3,747.5		$ 4,056.8
Sales to AEP Affiliates	0		0
TOTAL REVENUES	3,747.5		4,056.8
Expenses
Other Operation	602.1		666
Maintenance	249.5		274.5
Depreciation and Amortization	672.2		605.8
Taxes Other Than Income Taxes	321.1		309.9
TOTAL EXPENSES	2,995.9		3,268.4
OPERATING INCOME (LOSS)	751.6		788.4
Other Income (Expense):
Other Income	(4.4)		8.6
Allowance for Equity Funds Used During Construction	31.4		28.9
Non-Service Cost Components of Net Periodic Benefit Cost	29.7		30
Interest Expense	(292.1)		(255.8)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	516.2		600.1
Income Tax Expense (Benefit)	46.5		44.5
Equity Earnings (Loss) of Unconsolidated Subsidiaries	29.6		18.5
Net Income (Loss)	499.3		574.1
Net Income (Loss) Attributable to Noncontrolling Interests	4.1		1.3
Earnings Attributable to Common Shareholders	$ 495.2		$ 572.8
Earnings Per Share
Weighted Average Number of Basic AEP Common Shares Outstanding	494,596,869		493,309,076
Total Basic Earnings Per Share Attributable to AEP Common Shareholders	$ 1		$ 1.16
Weighted Average Number of Diluted AEP Common Shares Outstanding	496,608,918		494,484,144
Total Diluted Earnings Per Share Attributable to AEP Common Shareholders	$ 1		$ 1.16
Common Stock, Dividends Per Share, Declared	$ 0.70		$ 0.67
Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	$ 2,193		$ 2,372.3
Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	1,075.2		1,179.8
Generation and Marketing [Member]
Revenues
Revenue from Contracts with Customers	408.4		439.7
Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	70.9		65
Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	184.5		294.7
Expenses
Cost of Goods and Services Sold	355.3		550.4
Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	795.7		861.8
AEP Texas Inc. [Member]
Revenues
Sales to AEP Affiliates	31.1		40.2
TOTAL REVENUES	423.6		390.7
Expenses
Other Operation	117.5		109.8
Maintenance	20.6		25.3
Depreciation and Amortization	162.5		138.9
Taxes Other Than Income Taxes	34		36.5
TOTAL EXPENSES	334.6		319.9
OPERATING INCOME (LOSS)	89		70.8
Other Income (Expense):
Interest Income	0.6		0.4
Allowance for Equity Funds Used During Construction	5.1		1.8
Non-Service Cost Components of Net Periodic Benefit Cost	2.8		2.8
Interest Expense	(42.5)		(37.4)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	55		38.4
Income Tax Expense (Benefit)	7.4		4
Net Income (Loss)	47.6		34.4
AEP Texas Inc. [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	391.6		349.8
AEP Texas Inc. [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.9		0.7
AEP Texas Inc. [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	0	[1]	0	[2]
Expenses
Cost of Goods and Services Sold	0		9.4
AEP Transmission Co [Member]
Revenues
Sales to AEP Affiliates	233.7		193.2
TOTAL REVENUES	295.6		243.5
Expenses
Other Operation	23.8		17
Maintenance	3.2		3.2
Depreciation and Amortization	56		40.3
Taxes Other Than Income Taxes	50.4		41.4
TOTAL EXPENSES	133.4		101.9
OPERATING INCOME (LOSS)	162.2		141.6
Other Income (Expense):
Interest Income	0.8		0.7
Allowance for Equity Funds Used During Construction	16.2		11.3
Interest Expense	(29.6)		(21.7)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	149.6		131.9
Income Tax Expense (Benefit)	31.8		27.6
Net Income (Loss)	117.8		104.3
AEP Transmission Co [Member] | Transmission [Member]
Revenues
Revenue from Contracts with Customers	61.3		50.3
AEP Transmission Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.6		0
AEP Transmission Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	0	[1]	0	[2]
Appalachian Power Co [Member]
Revenues
Sales to AEP Affiliates	49.7		51.7
TOTAL REVENUES	749.4		792.8
Expenses
Other Operation	134		136.9
Maintenance	50.3		61.5
Depreciation and Amortization	122.2		112.5
Taxes Other Than Income Taxes	37.9		35.9
TOTAL EXPENSES	578		640.7
OPERATING INCOME (LOSS)	171.4		152.1
Other Income (Expense):
Interest Income	0.3		0.8
Allowance for Equity Funds Used During Construction	2.4		1.7
Non-Service Cost Components of Net Periodic Benefit Cost	4.7		4.3
Interest Expense	(53.1)		(49.3)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	125.7		109.6
Income Tax Expense (Benefit)	10.4		(24.1)
Net Income (Loss)	115.3		133.7
Appalachian Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	697		738.7
Appalachian Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.7		2.4
Appalachian Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	54.1	[1]	67.5	[2]
Sales to AEP Affiliates	33		35
Expenses
Cost of Goods and Services Sold	111		183.3
Appalachian Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	122.6		110.6
Indiana Michigan Power Co [Member]
Revenues
Sales to AEP Affiliates	2.9		2.3
Other Revenues - Affiliated	12.5		13.3
TOTAL REVENUES	570.3		614.3
Expenses
Purchased Electricity from AEP Affiliates	36.2		59.8
Other Operation	144.7		140.5
Maintenance	49.1		58.3
Depreciation and Amortization	93.9		86.2
Taxes Other Than Income Taxes	26.4		27.3
TOTAL EXPENSES	453.6		499.3
OPERATING INCOME (LOSS)	116.7		115
Other Income (Expense):
Other Income	2.5		5.7
Allowance for Equity Funds Used During Construction	2		6.2
Non-Service Cost Components of Net Periodic Benefit Cost	4.2		4.4
Interest Expense	(30.7)		(28.9)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	92.7		96.2
Income Tax Expense (Benefit)	0.4		(2.7)
Net Income (Loss)	92.3		98.9
Indiana Michigan Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	553.4		596.7
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	1.5		2
Sales to AEP Affiliates	16		15
Indiana Michigan Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	78.4	[1]	111.9	[2]
Expenses
Cost of Goods and Services Sold	53.2		57.6
Indiana Michigan Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	50.1		69.6
Ohio Power Co [Member]
Revenues
Sales to AEP Affiliates	8.4		7.5
TOTAL REVENUES	690.3		836.8
Expenses
Purchased Electricity from AEP Affiliates	42.4		46.1
Amortization of Generation Deferrals	0		32.4
Other Operation	177.3		216.9
Maintenance	31.6		32.5
Depreciation and Amortization	70.5		63.3
Taxes Other Than Income Taxes	112		108.9
TOTAL EXPENSES	582.9		674.3
OPERATING INCOME (LOSS)	107.4		162.5
Other Income (Expense):
Interest Income	0.2		0.8
Carrying Costs Income	0.4		0.2
Allowance for Equity Funds Used During Construction	1.9		5.2
Non-Service Cost Components of Net Periodic Benefit Cost	3.8		3.7
Interest Expense	(28.9)		(24.6)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	84.8		147.8
Income Tax Expense (Benefit)	9.7		19.8
Net Income (Loss)	75.1		128
Ohio Power Co [Member] | Transmission and Distribution Utilities [Member]
Revenues
Revenue from Contracts with Customers	679.2		826.5
Ohio Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	2.7		2.8
Ohio Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	0	[1]	0	[2]
Ohio Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	149.1		174.2
Public Service Co Of Oklahoma [Member]
Revenues
Sales to AEP Affiliates	1.1		1.6
TOTAL REVENUES	297.3		332.8
Expenses
Other Operation	87.2		73.6
Maintenance	24.4		22.5
Depreciation and Amortization	44.7		43.5
Taxes Other Than Income Taxes	11.3		11.4
TOTAL EXPENSES	294.9		311.9
OPERATING INCOME (LOSS)	2.4		20.9
Other Income (Expense):
Interest Income	0.1		0
Allowance for Equity Funds Used During Construction	1		0.1
Non-Service Cost Components of Net Periodic Benefit Cost	2.1		2.1
Interest Expense	(15.8)		(16.9)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	(10.2)		6.2
Income Tax Expense (Benefit)	0.1		0
Net Income (Loss)	(10.3)		6.2
Public Service Co Of Oklahoma [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	295.4		329.2
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.8		2
Public Service Co Of Oklahoma [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	1.9	[1]	8.6	[2]
Expenses
Cost of Goods and Services Sold	16.9		38
Public Service Co Of Oklahoma [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	110.4		122.9
Southwestern Electric Power Co [Member]
Revenues
Sales to AEP Affiliates	7.5		6.4
TOTAL REVENUES	385.9		421.1
Expenses
Other Operation	92.2		84.6
Maintenance	33.8		28.9
Depreciation and Amortization	67.3		62.1
Taxes Other Than Income Taxes	25.3		25.3
TOTAL EXPENSES	350.8		367
OPERATING INCOME (LOSS)	35.1		54.1
Other Income (Expense):
Interest Income	0.6		0.7
Allowance for Equity Funds Used During Construction	1.4		1.8
Non-Service Cost Components of Net Periodic Benefit Cost	2.1		2.1
Interest Expense	(30.1)		(29.7)
INCOME BEFORE INCOME TAX EXPENSE AND EQUITY EARNINGS	9.1		29
Income Tax Expense (Benefit)	(6.2)		0.7
Equity Earnings (Loss) of Unconsolidated Subsidiaries	0.8		0.7
Net Income (Loss)	16.1		29
Net Income (Loss) Attributable to Noncontrolling Interests	1		1.2
Earnings Attributable to Common Shareholders	15.1		27.8
Southwestern Electric Power Co [Member] | Vertically Integrated Utilities [Member]
Revenues
Revenue from Contracts with Customers	377.6		414.3
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Revenues
Revenue from Contracts with Customers	0.8		0.4
Southwestern Electric Power Co [Member] | Fuel and Other Consumables Used for Electric Generation [Member]
Revenues
Revenue from Contracts with Customers	34.1	[1]	57.2	[2]
Expenses
Cost of Goods and Services Sold	89.1		133.5
Southwestern Electric Power Co [Member] | Purchased Electricity for Resale [Member]
Expenses
Cost of Goods and Services Sold	$ 43.1		$ 32.6
[1]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $33 million primarily relating to the PPA with KGPCo. The remaining affiliated amounts were immaterial.
[2]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $35 million primarily relating to the PPA with KGPCo. The remaining affiliated amounts were immaterial.

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Revenue from Contracts with Customers		$ 3,747.5	$ 4,056.8
Net Income (Loss)		499.3	574.1
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax		(67)	(28.9)
Amortization of Pension and OPEB Deferred Costs, Net of Tax		(1.8)	(1.4)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)		(68.8)	(30.3)
TOTAL COMPREHENSIVE INCOME (LOSS)		430.5	543.8
Total Comprehensive Income (Loss) Attributable to Noncontrolling Interest		4.1	1.3
TOTAL COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO COMMON SHAREHOLDERS		426.4	542.5
Appalachian Power Co [Member]
Net Income (Loss)		115.3	133.7
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax		(4.2)	(0.2)
Amortization of Pension and OPEB Deferred Costs, Net of Tax		(0.9)	(0.6)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)		(5.1)	(0.8)
TOTAL COMPREHENSIVE INCOME (LOSS)		110.2	132.9
AEP Texas Inc. [Member]
Net Income (Loss)		47.6	34.4
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax		0.3	0.3
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)		0.3	0.3
TOTAL COMPREHENSIVE INCOME (LOSS)		47.9	34.7
Indiana Michigan Power Co [Member]
Net Income (Loss)		92.3	98.9
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax		0.4	0.4
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)		0.4	0.4
TOTAL COMPREHENSIVE INCOME (LOSS)		92.7	99.3
Ohio Power Co [Member]
Net Income (Loss)		75.1	128
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax		0	(0.3)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)			(0.3)
TOTAL COMPREHENSIVE INCOME (LOSS)		75.1	127.7
Public Service Co Of Oklahoma [Member]
Net Income (Loss)		(10.3)	6.2
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax		(0.2)	(0.2)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)		(0.2)	(0.2)
TOTAL COMPREHENSIVE INCOME (LOSS)		(10.5)	6
Southwestern Electric Power Co [Member]
Net Income (Loss)		16.1	29
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax		0.4	0.4
Amortization of Pension and OPEB Deferred Costs, Net of Tax		(0.4)	(0.3)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)		0	0.1
TOTAL COMPREHENSIVE INCOME (LOSS)		16.1	29.1
Total Comprehensive Income (Loss) Attributable to Noncontrolling Interest		1	1.2
TOTAL COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO COMMON SHAREHOLDERS		15.1	27.9
Generation and Marketing Revenues [Member]
Revenue from Contracts with Customers		408.4	439.7
Reclassification out of Accumulated Other Comprehensive Income [Member] | Generation and Marketing Revenues [Member]
Revenue from Contracts with Customers	[1]	(0.1)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
OTHER COMPREHENSIVE INCOME
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)		(1.8)	(1.4)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | Appalachian Power Co [Member]
OTHER COMPREHENSIVE INCOME
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)		(0.9)	(0.6)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | AEP Texas Inc. [Member]
OTHER COMPREHENSIVE INCOME
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)		0	0
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | Indiana Michigan Power Co [Member]
OTHER COMPREHENSIVE INCOME
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)		0	0
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | Southwestern Electric Power Co [Member]
OTHER COMPREHENSIVE INCOME
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)		(0.4)	$ (0.3)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Generation and Marketing Revenues [Member]
Revenue from Contracts with Customers	[1]	$ 0
[1]	(a) The change in fair value includes $5 million

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash Flow Hedges, Tax	$ (17.8)	$ (7.7)
Amortization of Pension and OPEB Deferred Costs, Tax	(0.5)	(0.4)
Appalachian Power Co [Member]
Cash Flow Hedges, Tax	(1.1)	(0.1)
Amortization of Pension and OPEB Deferred Costs, Tax	(0.3)	(0.2)
AEP Texas Inc. [Member]
Cash Flow Hedges, Tax	0.1	0.1
Indiana Michigan Power Co [Member]
Cash Flow Hedges, Tax	0.1	0.1
Amortization of Pension and OPEB Deferred Costs, Tax	0	0
Ohio Power Co [Member]
Cash Flow Hedges, Tax	0	(0.1)
Public Service Co Of Oklahoma [Member]
Cash Flow Hedges, Tax	(0.1)	(0.1)
Southwestern Electric Power Co [Member]
Cash Flow Hedges, Tax	0.1	0.1
Amortization of Pension and OPEB Deferred Costs, Tax	$ (0.1)	$ (0.1)

Condensed Consolidated Statemen

Condensed Consolidated Statements of Changes in Equity - USD ($) $ in Millions	Total	Appalachian Power Co [Member]	AEP Texas Inc. [Member]	AEP Transmission 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]Appalachian Power Co [Member]	Additional Paid-in Capital [Member]AEP Texas Inc. [Member]	Additional Paid-in Capital [Member]AEP Transmission 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]Appalachian Power Co [Member]	Retained Earnings [Member]AEP Texas Inc. [Member]	Retained Earnings [Member]AEP Transmission 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]Appalachian Power Co [Member]	Accumulated Other Comprehensive Income [Member]AEP Texas Inc. [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]
Beginning Balance at Dec. 31, 2018				$ 3,569.8															$ 2,480.6									$ 1,089.2
Beginning Balance at Dec. 31, 2018	$ 19,059.4	$ 4,006.1	$ 2,580.5		$ 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		$ 1,828.7	$ 1,257.9		$ 980.9	$ 838.8	$ 364	$ 676.6	$ 9,325.3		$ 1,922	$ 1,337.7		$ 1,329.1	$ 1,136.4	$ 724.7	$ 1,508.4	$ (120.4)	$ (5)	$ (15.1)	$ (13.8)	$ 1	$ 2.1	$ (5.4)	$ 31	$ 0.3
Beginning Balance, Shares at Dec. 31, 2018									513,500,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock, Value	14.5								$ 1.2						13.3
Issuance of Common Stock, Shares									100,000
Common Stock Dividends	(333.6)																							(332.5)	[1]
Common Stock Dividends		(50)			(20)	(25)	(11.3)	(18.7)																		(50)			(20)	(25)	(11.3)	(18.7)
Common Stock Dividends								(1.1)																																(1.1)	(1.1)
Other Changes in Equity	(55.6)														(56.6)	[2]								(62.1)																1
Capital Contribution from Member			200															200
Net Income (Loss)	572.8							27.8																572.8								27.8
Net Income (Loss) Attributable to Noncontrolling Interests	1.3							1.2																																1.3	1.2
Net Income (Loss)	574.1	133.7	34.4	104.3	98.9	128	6.2	29																		133.7	34.4	104.3	98.9	128	6.2
Other Comprehensive Income (Loss)	(30.3)	(0.8)	0.3		0.4	(0.3)	(0.2)	0.1																									(30.3)	(0.8)	0.3	0.4	(0.3)	(0.2)	0.1
Ending Balance at Mar. 31, 2019				3,674.1															2,480.6									1,193.5
Ending Balance at Mar. 31, 2019	$ 19,228.5	4,089	2,815.2		2,432.1	2,400.1	1,242.7	2,324.9	$ 3,338.6	260.4	56.6	321.2	157.2	135.7	6,442.8		1,828.7	1,457.9		980.9	838.8	364	676.6	9,565.6		2,005.7	1,372.1		1,408	1,239.4	719.6	1,517.5	(150.7)	(5.8)	(14.8)	(13.4)	0.7	1.9	(5.3)	32.2	0.4
Ending Balance, Shares at Mar. 31, 2019									513,600,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends Per Share, Declared	$ 0.67
Beginning Balance at Dec. 31, 2019				4,009.5															2,480.6									1,528.9
Beginning Balance at Dec. 31, 2019	$ 19,913.2	4,172.4	2,961.1		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		1,828.7	1,457.9		980.9	838.8	364	676.6	9,900.9		2,078.3	1,516		1,518.5	1,348.5	851	1,629.5	(147.7)	5	(12.8)	(11.6)	0	1.1	(1.3)	281	0.6
Beginning Balance, Shares at Dec. 31, 2019	514,373,631						10,482,000		514,400,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock, Value	$ 56.1								$ 6.8						49.3
Issuance of Common Stock, Shares									1,000,000
Common Stock Dividends	(363.7)																							(359.1)	[1]
Common Stock Dividends		(50)			(21.3)	(21.9)																				(50)			(21.3)	(21.9)
Common Stock Dividends								(0.7)																																(4.6)	(0.7)
Other Changes in Equity	(30.2)														(29)									0																(1.2)
ASU 2016-13 Adoption	(1.8)				0.4	(0.3)	$ (0.3)	(1.6)																(1.8)					0.4	(0.3)	(0.3)	(1.6)
Capital Contribution from Member				185															185
Net Income (Loss)	495.2							15.1																495.2								15.1
Net Income (Loss) Attributable to Noncontrolling Interests	4.1							1																																4.1	1
Net Income (Loss)	499.3	115.3	47.6	117.8	92.3	75.1	(10.3)	16.1																		115.3	47.6	117.8	92.3	75.1	(10.3)
Other Comprehensive Income (Loss)	(68.8)	(5.1)	0.3		0.4		(0.2)	0																									(68.8)	(5.1)	0.3	0.4		(0.2)
Ending Balance at Mar. 31, 2020				$ 4,312.3															$ 2,665.6									$ 1,646.7
Ending Balance at Mar. 31, 2020	$ 20,007.7	$ 4,232.6	$ 3,009		$ 2,616.2	$ 2,562	$ 1,363.1	$ 2,458.1	$ 3,350.2	$ 260.4	$ 56.6	$ 321.2	$ 157.2	$ 135.7	$ 6,555.9		$ 1,828.7	$ 1,457.9		$ 980.9	$ 838.8	$ 364	$ 676.6	$ 10,038.8		$ 2,143.6	$ 1,563.6		$ 1,589.9	$ 1,402	$ 841	$ 1,646.2	$ (216.5)	$ (0.1)	$ (12.5)	$ (11.2)	$ 0	$ 0.9	$ (1.3)	$ 279.3	$ 0.9
Ending Balance, Shares at Mar. 31, 2020	515,411,847						10,482,000		515,400,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends Per Share, Declared	$ 0.70
[1]	Cash dividends declared per AEP common share were $0.70 and $0.67 for the three months ended March 31, 2020 and 2019 , respectively.
[2]	Includes $(62) million related to a forward equity purchase contract associated with the issuance of Equity Units.

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions		Mar. 31, 2020	Dec. 31, 2019
Current Assets
Cash and Cash Equivalents		$ 1,554.6	$ 246.8
Restricted Cash		116.2	185.8
Other Temporary Investments		185.2	202.7
Accounts Receivable:
Customers		617.9	625.3
Accrued Unbilled Revenues		242.2	222.4
Pledged Accounts Receivable - AEP Credit		885.2	873.9
Miscellaneous		41.1	27.2
Allowance for Uncollectible Accounts		(44.9)	(43.7)
Total Accounts Receivable		1,741.5	1,705.1
Fuel		550.9	528.5
Materials and Supplies		645	640.7
Risk Management Assets		130.4	172.8
Regulatory Asset for Under-Recovered Fuel Costs		80.8	92.9
Margin Deposits		68.3	60.4
Prepayments and Other Current Assets		219.1	242.1
TOTAL CURRENT ASSETS		5,292	4,077.8
Property, Plant and Equipment
Generation		22,853.7	22,762.4
Transmission		25,314.2	24,808.6
Distribution		22,824.4	22,443.4
Other Property, Plant and Equipment		4,913.2	4,811.5
Construction Work in Progress		4,511.5	4,319.8
Total Property, Plant and Equipment		80,417	79,145.7
Accumulated Depreciation and Amortization		19,368.1	19,007.6
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		61,048.9	60,138.1
Other Noncurrent Assets
Regulatory Assets		3,197.4	3,158.8
Securitized Assets		789.1	858.1
Spent Nuclear Fuel and Decommissioning Trusts		2,679.2	2,975.7
Goodwill		52.5	52.5
Long-term Risk Management Assets		323.7	266.6
Operating Lease Assets		926.7	957.4
Deferred Charges and Other Noncurrent Assets		3,414.5	3,407.3
TOTAL OTHER NONCURRENT ASSETS		11,383.1	11,676.4
TOTAL ASSETS		77,724	75,892.3
Current Liabilities
Accounts Payable		1,593.4	2,085.8
Short-term Debt:
Securitized Debt for Receivables - AEP Credit	[1]	724	710
Other Short-term Debt		3,740.1	2,128.3
Total Short-term Debt		4,464.1	2,838.3
Long-term Debt Due Within One Year		2,109.7	1,598.7
Risk Management Liabilities		156.8	114.3
Customer Deposits		361	366.1
Accrued Taxes		1,255.4	1,357.8
Accrued Interest		307.9	243.6
Obligations Under Operating Leases		234.3	234.1
Regulatory Liability for Over-Recovered Fuel Costs		137.6	86.6
Other Current Liabilities		1,034.5	1,373.8
TOTAL CURRENT LIABILITIES		11,654.7	10,299.1
Noncurrent Liabilities
Long-term Debt		25,783	25,126.8
Affiliated Long Term Debt Noncurrent		0	0
Long-term Risk Management Liabilities		291.9	261.8
Deferred Income Taxes		7,668.5	7,588.2
Regulatory Liabilities and Deferred Investment Tax Credits		8,049.2	8,457.6
Asset Retirement Obligations		2,254.2	2,216.6
Employee Benefits and Pension Obligations		451	466
Obligations Under Operating Leases		736.3	734.6
Deferred Credits and Other Noncurrent Liabilities		709.5	719.8
TOTAL NONCURRENT LIABILITIES		45,943.6	45,571.4
TOTAL LIABILITIES		57,598.3	55,870.5
Rate Matters
Commitments and Contingencies
Redeemable Noncontrolling Interest		64.8	65.7
Contingently Reedemable Performance Share Awards		53.2	42.9
Total Mezzanine Equity		118	108.6
Equity
Common Stock		3,350.2	3,343.4
Paid-in Capital		6,555.9	6,535.6
Retained Earnings		10,038.8	9,900.9
Accumulated Other Comprehensive Income (Loss)		(216.5)	(147.7)
TOTAL COMMON SHAREHOLDER'S EQUITY		19,728.4	19,632.2
Noncontrolling Interests		279.3	281
TOTAL EQUITY		20,007.7	19,913.2
TOTAL LIABILITIES AND EQUITY		77,724	75,892.3
AEP Texas Inc. [Member]
Current Assets
Cash and Cash Equivalents		0.1	3.1
Restricted Cash		100.1	154.7
Advances to Affiliates		7.1	207.2
Accounts Receivable:
Customers		130.1	116
Affiliated Companies		10.4	10.1
Accrued Unbilled Revenues		88.6	68.8
Miscellaneous		0.4	0.3
Allowance for Uncollectible Accounts		(1.8)	(1.8)
Total Accounts Receivable		227.7	193.4
Fuel		6.4	5.9
Materials and Supplies		63.8	56.7
Accrued Tax Benefits		51.5	66.1
Prepayments and Other Current Assets		6.6	5.8
TOTAL CURRENT ASSETS		463.3	692.9
Property, Plant and Equipment
Generation		351.6	351.7
Transmission		4,624.7	4,466.5
Distribution		4,303.1	4,215.2
Other Property, Plant and Equipment		829.1	805.9
Construction Work in Progress		747	763.9
Total Property, Plant and Equipment		10,855.5	10,603.2
Accumulated Depreciation and Amortization		1,800.1	1,758.1
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		9,055.4	8,845.1
Other Noncurrent Assets
Regulatory Assets		272.2	280.6
Securitized Assets		560.5	623.4
Deferred Charges and Other Noncurrent Assets		219.1	147.1
TOTAL OTHER NONCURRENT ASSETS		1,051.8	1,051.1
TOTAL ASSETS		10,570.5	10,589.1
Current Liabilities
Advances from Affiliates		63.9	0
Accounts Payable		233.1	256.8
Affiliated Companies		20.3	35.6
Short-term Debt:
Long-term Debt Due Within One Year		289	392.1
Accrued Taxes		109.2	84.9
Accrued Interest		54.8	35.7
Oklaunion Purchase Power Agreement - Current		15.1	22.1
Obligations Under Operating Leases		13	12
Provision for Refund		62.9	64.7
Other Current Liabilities		104.3	123.3
TOTAL CURRENT LIABILITIES		965.6	1,027.2
Noncurrent Liabilities
Long-term Debt		4,156.4	4,166.3
Deferred Income Taxes		961.8	965.4
Regulatory Liabilities and Deferred Investment Tax Credits		1,321.8	1,316.9
Obligations Under Operating Leases		70.7	71.1
Deferred Credits and Other Noncurrent Liabilities		85.2	81.1
TOTAL NONCURRENT LIABILITIES		6,595.9	6,600.8
TOTAL LIABILITIES		7,561.5	7,628
Rate Matters
Commitments and Contingencies
Equity
Paid-in Capital		1,457.9	1,457.9
Retained Earnings		1,563.6	1,516
Accumulated Other Comprehensive Income (Loss)		(12.5)	(12.8)
TOTAL EQUITY		3,009	2,961.1
TOTAL LIABILITIES AND EQUITY		10,570.5	10,589.1
AEP Transmission Co [Member]
Current Assets
Cash and Cash Equivalents		0	0
Advances to Affiliates		128.4	85.4
Accounts Receivable:
Customers		19.3	19
Affiliated Companies		87.8	66.1
Total Accounts Receivable		107.1	85.1
Materials and Supplies		13.4	13.8
Accrued Tax Benefits		0.1	9.3
Prepayments and Other Current Assets		3.4	3.8
TOTAL CURRENT ASSETS		252.4	197.4
Property, Plant and Equipment
Transmission		8,406.4	8,137.9
Other Property, Plant and Equipment		278.5	269.6
Construction Work in Progress		1,536.3	1,485.7
Total Property, Plant and Equipment		10,221.2	9,893.2
Accumulated Depreciation and Amortization		445.8	402.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		9,775.4	9,490.9
Other Noncurrent Assets
Regulatory Assets		2.5	4.2
Deferred Property Taxes		165.1	193.5
Deferred Charges and Other Noncurrent Assets		4.5	4.8
TOTAL OTHER NONCURRENT ASSETS		172.1	202.5
TOTAL ASSETS		10,199.9	9,890.8
Current Liabilities
Advances from Affiliates		297.4	137
Accounts Payable		334.2	493.4
Affiliated Companies		73.7	71.2
Short-term Debt:
Accrued Taxes		308.6	355.6
Accrued Interest		38.6	19.2
Obligations Under Operating Leases		2.1	2.1
Other Current Liabilities		17	14.6
TOTAL CURRENT LIABILITIES		1,071.6	1,093.1
Noncurrent Liabilities
Long-term Debt		3,427.8	3,427.3
Deferred Income Taxes		834.7	817.8
Regulatory Liabilities and Deferred Investment Tax Credits		551.6	540.9
Obligations Under Operating Leases		1.6	1.9
Deferred Credits and Other Noncurrent Liabilities		0.3	0.3
TOTAL NONCURRENT LIABILITIES		4,816	4,788.2
TOTAL LIABILITIES		5,887.6	5,881.3
Rate Matters
Commitments and Contingencies
Equity
Paid-in Captial		2,665.6	2,480.6
Retained Earnings		1,646.7	1,528.9
TOTAL MEMBER'S EQUITY		4,312.3	4,009.5
TOTAL LIABILITIES AND EQUITY		10,199.9	9,890.8
Appalachian Power Co [Member]
Current Assets
Cash and Cash Equivalents		2.8	3.3
Restricted Cash		15.7	23.5
Advances to Affiliates		21.8	22.1
Accounts Receivable:
Customers		132.6	129
Affiliated Companies		78	64.3
Accrued Unbilled Revenues		46.1	59.7
Miscellaneous		0.6	0.5
Allowance for Uncollectible Accounts		(2.9)	(2.6)
Total Accounts Receivable		254.4	250.9
Fuel		160	149.7
Materials and Supplies		100.4	105.2
Risk Management Assets		18.1	39.4
Regulatory Asset for Under-Recovered Fuel Costs		34.9	42.5
Prepayments and Other Current Assets		33.1	64
TOTAL CURRENT ASSETS		641.2	700.6
Property, Plant and Equipment
Generation		6,602.1	6,563.7
Transmission		3,613.2	3,584.1
Distribution		4,279.1	4,201.7
Other Property, Plant and Equipment		585.5	571.3
Construction Work in Progress		574	593.4
Total Property, Plant and Equipment		15,653.9	15,514.2
Accumulated Depreciation and Amortization		4,497	4,432.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		11,156.9	11,081.9
Other Noncurrent Assets
Regulatory Assets		464	457.2
Securitized Assets		228.5	234.7
Long-term Risk Management Assets		0.1	0.1
Operating Lease Assets		77.5	78.5
Deferred Charges and Other Noncurrent Assets		225.4	215.3
TOTAL OTHER NONCURRENT ASSETS		995.5	985.8
TOTAL ASSETS		12,793.6	12,768.3
Current Liabilities
Advances from Affiliates		355.3	236.7
Accounts Payable		198.7	307.8
Affiliated Companies		75.2	92.5
Short-term Debt:
Long-term Debt Due Within One Year		583.3	215.6
Risk Management Liabilities		15	1.9
Customer Deposits		84.5	85.8
Accrued Taxes		102.7	99.6
Accrued Interest		67	47.9
Obligations Under Operating Leases		15.4	15.2
Other Current Liabilities		90.1	123
TOTAL CURRENT LIABILITIES		1,587.2	1,226
Noncurrent Liabilities
Long-term Debt		3,769.1	4,148.2
Long-term Risk Management Liabilities		0.1	0
Deferred Income Taxes		1,680.9	1,680.8
Regulatory Liabilities and Deferred Investment Tax Credits		1,254.5	1,268.7
Asset Retirement Obligations		103.6	102.1
Employee Benefits and Pension Obligations		47.3	50.9
Obligations Under Operating Leases		63.1	64
Deferred Credits and Other Noncurrent Liabilities		55.2	55.2
TOTAL NONCURRENT LIABILITIES		6,973.8	7,369.9
TOTAL LIABILITIES		8,561	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		2,143.6	2,078.3
Accumulated Other Comprehensive Income (Loss)		(0.1)	5
TOTAL EQUITY		4,232.6	4,172.4
TOTAL LIABILITIES AND EQUITY		12,793.6	12,768.3
Indiana Michigan Power Co [Member]
Current Assets
Cash and Cash Equivalents		1.8	2
Advances to Affiliates		13.3	13.2
Accounts Receivable:
Customers		47.5	53.6
Affiliated Companies		51.1	53.7
Accrued Unbilled Revenues		1.8	2.5
Miscellaneous		1.3	0.3
Allowance for Uncollectible Accounts		(0.3)	(0.6)
Total Accounts Receivable		101.4	109.5
Fuel		71.7	56.2
Materials and Supplies		171.1	171.3
Risk Management Assets		6.7	9.8
Regulatory Asset for Under-Recovered Fuel Costs		1.2	3
Accrued Reimbursement of Spent Nuclear Fuel Costs		8.4	24
Prepayments and Other Current Assets		16.4	14
TOTAL CURRENT ASSETS		392	403
Property, Plant and Equipment
Generation		5,114	5,099.7
Transmission		1,647.5	1,641.8
Distribution		2,474.8	2,437.6
Other Property, Plant and Equipment		617.4	632.6
Construction Work in Progress		420.1	382.3
Total Property, Plant and Equipment		10,273.8	10,194
Accumulated Depreciation and Amortization		3,356.3	3,294.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		6,917.5	6,899.7
Other Noncurrent Assets
Regulatory Assets		459	482.1
Spent Nuclear Fuel and Decommissioning Trusts		2,679.2	2,975.7
Long-term Risk Management Assets		0.1	0.1
Operating Lease Assets		273.6	294.9
Deferred Charges and Other Noncurrent Assets		184	181.9
TOTAL OTHER NONCURRENT ASSETS		3,595.9	3,934.7
TOTAL ASSETS		10,905.4	11,237.4
Current Liabilities
Advances from Affiliates		103.7	114.4
Accounts Payable		131.5	169.4
Affiliated Companies		71	68.4
Short-term Debt:
Long-term Debt Due Within One Year		133.6	139.7
Risk Management Liabilities		1.7	0.5
Customer Deposits		38.8	39.4
Accrued Taxes		137.4	112.4
Accrued Interest		20.3	36.2
Obligations Under Operating Leases		85.3	87.3
Regulatory Liability for Over-Recovered Fuel Costs		26.7	6.1
Other Current Liabilities		70.8	109.6
TOTAL CURRENT LIABILITIES		820.8	883.4
Noncurrent Liabilities
Long-term Debt		2,894.4	2,910.5
Long-term Risk Management Liabilities		0.1	0
Deferred Income Taxes		984.3	979.7
Regulatory Liabilities and Deferred Investment Tax Credits		1,550.4	1,891.4
Asset Retirement Obligations		1,766	1,748.6
Obligations Under Operating Leases		209	211.6
Deferred Credits and Other Noncurrent Liabilities		64.2	67.8
TOTAL NONCURRENT LIABILITIES		7,468.4	7,809.6
TOTAL LIABILITIES		8,289.2	8,693
Rate Matters
Commitments and Contingencies
Equity
Common Stock		56.6	56.6
Paid-in Capital		980.9	980.9
Retained Earnings		1,589.9	1,518.5
Accumulated Other Comprehensive Income (Loss)		(11.2)	(11.6)
TOTAL EQUITY		2,616.2	2,544.4
TOTAL LIABILITIES AND EQUITY		10,905.4	11,237.4
Ohio Power Co [Member]
Current Assets
Cash and Cash Equivalents		3.1	3.7
Accounts Receivable:
Customers		42.9	53
Affiliated Companies		73.1	59.3
Accrued Unbilled Revenues		34.2	20.3
Miscellaneous		3.8	0.5
Allowance for Uncollectible Accounts		(0.4)	(0.7)
Total Accounts Receivable		153.6	132.4
Materials and Supplies		58.3	52.3
Renewable Energy Credits		26.9	30.9
Prepayments and Other Current Assets		23.7	19.2
TOTAL CURRENT ASSETS		265.6	238.5
Property, Plant and Equipment
Transmission		2,713	2,686.3
Distribution		5,404.5	5,323.5
Other Property, Plant and Equipment		797.2	765.8
Construction Work in Progress		412.5	394.4
Total Property, Plant and Equipment		9,327.2	9,170
Accumulated Depreciation and Amortization		2,292.8	2,263
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		7,034.4	6,907
Other Noncurrent Assets
Regulatory Assets		396.4	351.8
Deferred Charges and Other Noncurrent Assets		485.6	546.3
TOTAL OTHER NONCURRENT ASSETS		882	898.1
TOTAL ASSETS		8,182	8,043.6
Current Liabilities
Advances from Affiliates		29.4	131
Accounts Payable		220.3	233.7
Affiliated Companies		109	103.6
Short-term Debt:
Long-term Debt Due Within One Year		0.1	0.1
Risk Management Liabilities		8.7	7.3
Customer Deposits		74.1	70.6
Accrued Taxes		449.2	587.9
Obligations Under Operating Leases		13	12.5
Other Current Liabilities		139.5	151.2
TOTAL CURRENT LIABILITIES		1,043.3	1,297.9
Noncurrent Liabilities
Long-term Debt		2,429	2,081.9
Long-term Risk Management Liabilities		112.2	96.3
Deferred Income Taxes		871	849.4
Regulatory Liabilities and Deferred Investment Tax Credits		1,040.6	1,090.9
Obligations Under Operating Leases		79.8	76
Deferred Credits and Other Noncurrent Liabilities		44.1	42.7
TOTAL NONCURRENT LIABILITIES		4,576.7	4,237.2
TOTAL LIABILITIES		5,620	5,535.1
Rate Matters
Commitments and Contingencies
Equity
Common Stock		321.2	321.2
Paid-in Capital		838.8	838.8
Retained Earnings		1,402	1,348.5
TOTAL EQUITY		2,562	2,508.5
TOTAL LIABILITIES AND EQUITY		8,182	8,043.6
Public Service Co Of Oklahoma [Member]
Current Assets
Cash and Cash Equivalents		1.1	1.5
Advances to Affiliates		0	38.8
Accounts Receivable:
Customers		28.4	28.9
Affiliated Companies		19.9	20.6
Miscellaneous		0.8	0.6
Allowance for Uncollectible Accounts		(0.2)	(0.3)
Total Accounts Receivable		48.9	49.8
Fuel		19.6	12.2
Materials and Supplies		47.9	46.8
Risk Management Assets		6.4	15.8
Accrued Tax Benefits		5.7	11.3
Prepayments and Other Current Assets		13.4	12
TOTAL CURRENT ASSETS		143	188.2
Property, Plant and Equipment
Generation		1,577.2	1,574.6
Transmission		959.5	948.5
Distribution		2,724.3	2,684.8
Other Property, Plant and Equipment		350.3	342.1
Construction Work in Progress		144.9	133.4
Total Property, Plant and Equipment		5,756.2	5,683.4
Accumulated Depreciation and Amortization		1,615.8	1,580.1
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		4,140.4	4,103.3
Other Noncurrent Assets
Regulatory Assets		378.4	375.2
Employee Benefits and Pension Assets		44.2	43.9
Operating Lease Assets		38	36.8
Deferred Charges and Other Noncurrent Assets		34	4.1
TOTAL OTHER NONCURRENT ASSETS		494.6	460
TOTAL ASSETS		4,778	4,751.5
Current Liabilities
Advances from Affiliates		70.9	0
Accounts Payable		102.5	134.3
Affiliated Companies		39.8	59.3
Short-term Debt:
Long-term Debt Due Within One Year		263.2	13.2
Risk Management Liabilities		0.1	0
Customer Deposits		59.3	58.9
Accrued Taxes		42.4	22.9
Obligations Under Operating Leases		6	5.8
Regulatory Liability for Over-Recovered Fuel Costs		68	63.9
Other Current Liabilities		78.6	87.5
TOTAL CURRENT LIABILITIES		730.8	445.8
Noncurrent Liabilities
Long-term Debt		1,123.1	1,373
Deferred Income Taxes		629.6	628.3
Regulatory Liabilities and Deferred Investment Tax Credits		835	837.2
Asset Retirement Obligations		45.3	44.5
Obligations Under Operating Leases		32.1	31
Deferred Credits and Other Noncurrent Liabilities		19	18.4
TOTAL NONCURRENT LIABILITIES		2,684.1	2,932.4
TOTAL LIABILITIES		3,414.9	3,378.2
Rate Matters
Commitments and Contingencies
Equity
Common Stock		157.2	157.2
Paid-in Capital		364	364
Retained Earnings		841	851
Accumulated Other Comprehensive Income (Loss)		0.9	1.1
TOTAL EQUITY		1,363.1	1,373.3
TOTAL LIABILITIES AND EQUITY		4,778	4,751.5
Southwestern Electric Power Co [Member]
Current Assets
Cash and Cash Equivalents		1.4	1.6
Advances to Affiliates		2.1	2.1
Accounts Receivable:
Customers		25.6	29
Affiliated Companies		24.4	34.5
Miscellaneous		14.3	13.5
Allowance for Uncollectible Accounts		(0.3)	(1.7)
Total Accounts Receivable		64	75.3
Fuel		147.9	140.1
Materials and Supplies		93.8	94
Risk Management Assets		2.6	6.4
Regulatory Asset for Under-Recovered Fuel Costs		0	4.9
Prepayments and Other Current Assets		34.3	29.7
TOTAL CURRENT ASSETS		346.1	354.1
Property, Plant and Equipment
Generation		4,703	4,691.4
Transmission		2,061.6	2,056.5
Distribution		2,300.8	2,270.7
Other Property, Plant and Equipment		767.2	733.4
Construction Work in Progress		232.7	216.9
Total Property, Plant and Equipment		10,065.3	9,968.9
Accumulated Depreciation and Amortization		2,918.7	2,873.7
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		7,146.6	7,095.2
Other Noncurrent Assets
Regulatory Assets		236.6	222.4
Deferred Charges and Other Noncurrent Assets		214.8	160.5
TOTAL OTHER NONCURRENT ASSETS		451.4	382.9
TOTAL ASSETS		7,944.1	7,832.2
Current Liabilities
Advances from Affiliates		148.1	59.9
Accounts Payable		102.5	138
Affiliated Companies		37.3	53.6
Short-term Debt:
Other Short-term Debt		30.5	18.3
Long-term Debt Due Within One Year		121.2	121.2
Risk Management Liabilities		2.2	1.9
Customer Deposits		65.1	65
Accrued Taxes		93	41.8
Accrued Interest		21.9	34.6
Obligations Under Operating Leases		7.1	6.5
Regulatory Liability for Over-Recovered Fuel Costs		29.7	13.6
Other Current Liabilities		87.8	120.3
TOTAL CURRENT LIABILITIES		746.4	674.7
Noncurrent Liabilities
Long-term Debt		2,533.2	2,534.4
Long-term Risk Management Liabilities		2.9	3.1
Deferred Income Taxes		944.4	940.9
Regulatory Liabilities and Deferred Investment Tax Credits		885.8	892.3
Asset Retirement Obligations		219.7	196.7
Obligations Under Operating Leases		38.2	34.7
Deferred Credits and Other Noncurrent Liabilities		115.4	114.3
TOTAL NONCURRENT LIABILITIES		4,739.6	4,716.4
TOTAL LIABILITIES		5,486	5,391.1
Rate Matters
Commitments and Contingencies
Equity
Common Stock		135.7	135.7
Paid-in Capital		676.6	676.6
Retained Earnings		1,646.2	1,629.5
Accumulated Other Comprehensive Income (Loss)		(1.3)	(1.3)
TOTAL COMMON SHAREHOLDER'S EQUITY		2,457.2	2,440.5
Noncontrolling Interests		0.9	0.6
TOTAL EQUITY		2,458.1	2,441.1
TOTAL LIABILITIES AND EQUITY		$ 7,944.1	$ 7,832.2
[1]	Amount of securitized debt for receivables as accounted for under the “Transfers and Servicing” accounting guidance.

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Current Assets
Cash and Cash Equivalents	$ 1,554.6	$ 246.8
Restricted Cash	116.2	185.8
Other Temporary Investments	185.2	202.7
Fuel	550.9	528.5
Other Inventory, Supplies, Gross	645	640.7
Property, Plant and Equipment
Other Property, Plant and Equipment	4,913.2	4,811.5
Accumulated Depreciation and Amortization	19,368.1	19,007.6
Other Noncurrent Assets
Securitized Transition Assets	789.1	858.1
Current Liabilities
Long-term Debt Due Within One Year	2,109.7	1,598.7
Accrued Interest	307.9	243.6
Noncurrent Liabilities
Long-term Debt	$ 25,783	$ 25,126.8
Equity
Common Stock, Par Value Per Share	$ 6.50	$ 6.50
Common Stock, Shares Authorized	600,000,000	600,000,000
Common Stock, Shares, Issued	515,411,847	514,373,631
Treasury Stock, Shares	20,204,160	20,204,160
AEP Subsidiaries [Member]
Current Assets
Restricted Cash	$ 116.2	$ 185.8
Other Temporary Investments	163.6	187.8
Current Liabilities
Long-term Debt Due Within One Year	289.6	565.1
Noncurrent Liabilities
Long-term Debt	1,037.6	907
AEP Texas Inc. [Member]
Current Assets
Cash and Cash Equivalents	0.1	3.1
Restricted Cash	100.1	154.7
Fuel	6.4	5.9
Other Inventory, Supplies, Gross	63.8	56.7
Property, Plant and Equipment
Other Property, Plant and Equipment	829.1	805.9
Accumulated Depreciation and Amortization	1,800.1	1,758.1
Other Noncurrent Assets
Securitized Transition Assets	560.5	623.4
Current Liabilities
Long-term Debt Due Within One Year	289	392.1
Accrued Interest	54.8	35.7
Noncurrent Liabilities
Long-term Debt	4,156.4	4,166.3
AEP Texas Inc. [Member] | AEP Texas Transition Funding and Restoration Funding [Member]
Current Assets
Restricted Cash	100.1	154.7
Other Noncurrent Assets
Securitized Transition Assets	560.7	621.2
Current Liabilities
Long-term Debt Due Within One Year	178.3	281.4
Accrued Interest	4.9	7.5
Noncurrent Liabilities
Long-term Debt	484.7	495.4
Appalachian Power Co [Member]
Current Assets
Cash and Cash Equivalents	2.8	3.3
Restricted Cash	15.7	23.5
Fuel	160	149.7
Other Inventory, Supplies, Gross	100.4	105.2
Property, Plant and Equipment
Other Property, Plant and Equipment	585.5	571.3
Accumulated Depreciation and Amortization	4,497	4,432.3
Other Noncurrent Assets
Securitized Transition Assets	228.5	234.7
Current Liabilities
Long-term Debt Due Within One Year	583.3	215.6
Accrued Interest	67	47.9
Noncurrent Liabilities
Long-term Debt	$ 3,769.1	$ 4,148.2
Equity
Common Stock, Shares Authorized	30,000,000	30,000,000
Common Stock, Shares Outstanding	13,499,500	13,499,500
Indiana Michigan Power Co [Member]
Current Assets
Cash and Cash Equivalents	$ 1.8	$ 2
Fuel	71.7	56.2
Other Inventory, Supplies, Gross	171.1	171.3
Property, Plant and Equipment
Other Property, Plant and Equipment	617.4	632.6
Accumulated Depreciation and Amortization	3,356.3	3,294.3
Current Liabilities
Long-term Debt Due Within One Year	133.6	139.7
Accrued Interest	20.3	36.2
Noncurrent Liabilities
Long-term Debt	$ 2,894.4	$ 2,910.5
Equity
Common Stock, No Par Value	$ 0	$ 0
Common Stock, Shares Authorized	2,500,000	2,500,000
Common Stock, Shares Outstanding	1,400,000	1,400,000
Indiana Michigan Power Co [Member] | DCC Fuel [Member]
Current Liabilities
Long-term Debt Due Within One Year	$ 80	$ 86.1
Ohio Power Co [Member]
Current Assets
Cash and Cash Equivalents	3.1	3.7
Other Inventory, Supplies, Gross	58.3	52.3
Property, Plant and Equipment
Other Property, Plant and Equipment	797.2	765.8
Accumulated Depreciation and Amortization	2,292.8	2,263
Current Liabilities
Long-term Debt Due Within One Year	0.1	0.1
Noncurrent Liabilities
Long-term Debt	$ 2,429	$ 2,081.9
Equity
Common Stock, No Par Value	$ 0	$ 0
Common Stock, Shares Authorized	40,000,000	40,000,000
Common Stock, Shares Outstanding	27,952,473	27,952,473
Public Service Co Of Oklahoma [Member]
Current Assets
Cash and Cash Equivalents	$ 1.1	$ 1.5
Fuel	19.6	12.2
Other Inventory, Supplies, Gross	47.9	46.8
Property, Plant and Equipment
Other Property, Plant and Equipment	350.3	342.1
Accumulated Depreciation and Amortization	1,615.8	1,580.1
Current Liabilities
Long-term Debt Due Within One Year	263.2	13.2
Noncurrent Liabilities
Long-term Debt	$ 1,123.1	$ 1,373
Equity
Common Stock, Par Value Per Share	$ 15	$ 15
Common Stock, Shares Authorized	11,000,000	11,000,000
Common Stock, Shares, Issued	10,482,000	10,482,000
Common Stock, Shares Outstanding	9,013,000	9,013,000
Southwestern Electric Power Co [Member]
Current Assets
Cash and Cash Equivalents	$ 1.4	$ 1.6
Fuel	147.9	140.1
Other Inventory, Supplies, Gross	93.8	94
Property, Plant and Equipment
Other Property, Plant and Equipment	767.2	733.4
Accumulated Depreciation and Amortization	2,918.7	2,873.7
Current Liabilities
Long-term Debt Due Within One Year	121.2	121.2
Accrued Interest	21.9	34.6
Noncurrent Liabilities
Long-term Debt	$ 2,533.2	$ 2,534.4
Equity
Common Stock, Par Value Per Share	$ 18	$ 18
Common Stock, Shares Authorized	7,600,000	7,600,000
Common Stock, Shares Outstanding	7,536,640	7,536,640
Southwestern Electric Power Co [Member] | Sabine Mining Co [Member]
Current Assets
Fuel	$ 42	$ 47
Other Inventory, Supplies, Gross	23.3	23.1
Property, Plant and Equipment
Other Property, Plant and Equipment	213.5	212.3
Accumulated Depreciation and Amortization	$ 112	$ 107.5

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating Activities
Net Income (Loss)	$ 499.3	$ 574.1
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	672.2	605.8
Deferred Income Taxes	27.9	16.8
Allowance for Equity Funds Used During Construction	(31.4)	(28.9)
Mark-to-Market of Risk Management Contracts	57.4	65.5
Amortization of Nuclear Fuel	23.4	25.1
Property Taxes	(59.8)	(75.6)
Deferred Fuel Over/Under-Recovery, Net	63.1	32.5
Recovery of Ohio Capacity Costs, Net	0	14.7
Refund of Global Settlement	0	(4.1)
Change in Other Noncurrent Assets	(50.8)	(47.9)
Change in Other Noncurrent Liabilities	(74.8)	67.3
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(32.6)	57.5
Fuel, Materials and Supplies	(35.8)	(26.4)
Accounts Payable	(111.1)	(152.6)
Accrued Taxes, Net	(93.9)	(77)
Other Current Assets	5.3	(18.8)
Other Current Liabilities	(242.7)	(219.7)
Net Cash Flows from (Used for) Operating Activities	615.7	808.3
Investing Activities
Construction Expenditures	(1,792.7)	(1,565.4)
Purchases of Investment Securities	(632.7)	(130.4)
Sales of Investment Securities	635.6	111.9
Acquisitions of Nuclear Fuel	(1.3)	(32.4)
Other Investing Activities	25.1	33.5
Net Cash Flows from (Used for) Investing Activities	(1,766)	(1,582.8)
Financing Activities
Issuance of Common Stock, Net	56.1	14.5
Issuance of Long-term Debt	1,418.9	1,285.6
Issuance of Short-term Debt with Original Maturities greater than 90 Days	1,297.5	0
Change in Short-term Debt with Original Maturities less than 90 Days, Net	328.3	(52)
Retirement of Long-term Debt	(300.5)	(220.6)
Principal Payments for Finance Leases	(15.4)	(14.3)
Dividends Paid on Common Stock	(363.7)	(333.6)
Other Financing Activities	(32.7)	13.9
Net Cash Flows from (Used for) Financing Activities	2,388.5	693.5
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	1,238.2	(81)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	432.6	444.1
Cash and Cash Equivalents at Beginning of Period	246.8
Cash, Cash Equivalents and Restricted Cash at End of Period	1,670.8	363.1
Cash and Cash Equivalents at End of Period	1,554.6
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	212.6	168.9
Net Cash Paid (Received) for Income Taxes	(0.6)	(0.6)
Noncash Acquisitions Under Finance Leases	19.4	23.1
Construction Expenditures Included in Current Liabilities as of March 31,	874.1	846.3
Construction Expenditures Included in Noncurrent Liabilities as of March 31,	8.3	0
Expected Reimbursement for Spent Nuclear Fuel Dry Cask Storage	1.3	1
Stockholders' Equity, Other	30.2	55.6
AEP Texas Inc. [Member]
Operating Activities
Net Income (Loss)	47.6	34.4
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	162.5	138.9
Deferred Income Taxes	(7.6)	(11)
Allowance for Equity Funds Used During Construction	(5.1)	(1.8)
Property Taxes	(69.3)	(73.8)
Change in Other Noncurrent Assets	(10.8)	(3.2)
Change in Other Noncurrent Liabilities	3.2	(5.7)
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(34.3)	(7.8)
Fuel, Materials and Supplies	(7.6)	(1)
Accounts Payable	2.4	4.2
Accrued Taxes, Net	38.9	57.5
Other Current Assets	(1.4)	0.5
Other Current Liabilities	(4.6)	(4.4)
Net Cash Flows from (Used for) Operating Activities	113.9	126.8
Investing Activities
Construction Expenditures	(327.5)	(343.1)
Change in Advances to Affiliates, Net	200.1	0.3
Other Investing Activities	7.4	6.2
Net Cash Flows from (Used for) Investing Activities	(120)	(336.6)
Financing Activities
Capital Contributions from Parent	0	200
Change in Advances from Affiliates, Net	63.9	55.2
Retirement of Long-term Debt	(114.3)	(103.5)
Principal Payments for Finance Leases	(1.5)	(1.2)
Other Financing Activities	0.4	0.2
Net Cash Flows from (Used for) Financing Activities	(51.5)	150.7
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	(57.6)	(59.1)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	157.8	159.8
Cash and Cash Equivalents at Beginning of Period	3.1
Cash, Cash Equivalents and Restricted Cash at End of Period	100.2	100.7
Cash and Cash Equivalents at End of Period	0.1
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	21.1	22.4
Net Cash Paid (Received) for Income Taxes	0	(5.6)
Noncash Acquisitions Under Finance Leases	3.7	2.4
Construction Expenditures Included in Current Liabilities as of March 31,	175.1	195.7
AEP Transmission Co [Member]
Operating Activities
Net Income (Loss)	117.8	104.3
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	56	40.3
Deferred Income Taxes	13.7	14.5
Allowance for Equity Funds Used During Construction	(16.2)	(11.3)
Property Taxes	28.4	23.2
Change in Other Noncurrent Assets	2.4	2.7
Change in Other Noncurrent Liabilities	0.6	2.2
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(22)	(8.2)
Fuel, Materials and Supplies	0.4	(0.6)
Accounts Payable	22.7	11.4
Accrued Taxes, Net	(37.8)	(32.1)
Accrued Interest	19.4	19.2
Other Current Assets	0.4	0.4
Other Current Liabilities	1.2	0.2
Net Cash Flows from (Used for) Operating Activities	187	166.2
Investing Activities
Construction Expenditures	(491.5)	(365)
Change in Advances to Affiliates, Net	(43)	23.4
Acquisitions of Assets	(1.7)	(2.5)
Other Investing Activities	3.8	0.3
Net Cash Flows from (Used for) Investing Activities	(532.4)	(343.8)
Financing Activities
Capital Contributions from Parent	185	0
Change in Advances from Affiliates, Net	160.4	177.7
Other Financing Activities	0	(0.1)
Net Cash Flows from (Used for) Financing Activities	345.4	177.6
Net Increase (Decrease) in Cash and Cash Equivalents	0	0
Cash and Cash Equivalents at Beginning of Period	0	0
Cash and Cash Equivalents at End of Period	0	0
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	9.3	1.6
Net Cash Paid (Received) for Income Taxes	0.1	(1.2)
Construction Expenditures Included in Current Liabilities as of March 31,	290.6	261.1
Appalachian Power Co [Member]
Operating Activities
Net Income (Loss)	115.3	133.7
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	122.2	112.5
Deferred Income Taxes	(5.1)	(45)
Allowance for Equity Funds Used During Construction	(2.4)	(1.7)
Mark-to-Market of Risk Management Contracts	29.6	50.6
Deferred Fuel Over/Under-Recovery, Net	7.6	20.8
Change in Other Noncurrent Assets	(24.4)	(12.1)
Change in Other Noncurrent Liabilities	(16.1)	(20.5)
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(2.6)	19.5
Fuel, Materials and Supplies	(5.5)	(9.6)
Accounts Payable	(86.6)	(8.3)
Accrued Taxes, Net	14.5	13.7
Other Current Assets	19.2	(0.8)
Other Current Liabilities	(11.1)	(2.3)
Net Cash Flows from (Used for) Operating Activities	154.6	250.5
Investing Activities
Construction Expenditures	(219.1)	(205.1)
Change in Advances to Affiliates, Net	0.3	(193.6)
Other Investing Activities	1.1	15.2
Net Cash Flows from (Used for) Investing Activities	(217.7)	(383.5)
Financing Activities
Issuance of Long-term Debt	0	393.3
Change in Advances from Affiliates, Net	118.6	(205.6)
Retirement of Long-term Debt	(12.2)	(12)
Principal Payments for Finance Leases	(1.8)	(1.6)
Dividends Paid on Common Stock	(50)	(50)
Other Financing Activities	0.2	0.3
Net Cash Flows from (Used for) Financing Activities	54.8	124.4
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	(8.3)	(8.6)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	26.8	29.8
Cash and Cash Equivalents at Beginning of Period	3.3
Cash, Cash Equivalents and Restricted Cash at End of Period	18.5	21.2
Cash and Cash Equivalents at End of Period	2.8
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	31.9	14.5
Net Cash Paid (Received) for Income Taxes	0	8
Noncash Acquisitions Under Finance Leases	1.9	2.1
Construction Expenditures Included in Current Liabilities as of March 31,	103.7	87.8
Indiana Michigan Power Co [Member]
Operating Activities
Net Income (Loss)	92.3	98.9
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	93.9	86.2
Deferred Income Taxes	(16.3)	(13.9)
Deferral of Incremental Nuclear Refueling Outage Expenses, Net	15.2	(14.8)
Allowance for Equity Funds Used During Construction	(2)	(6.2)
Mark-to-Market of Risk Management Contracts	4.4	4.7
Amortization of Nuclear Fuel	23.4	25.1
Deferred Fuel Over/Under-Recovery, Net	22.5	(5.2)
Change in Other Noncurrent Assets	14.4	13.5
Change in Other Noncurrent Liabilities	10	5.2
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	8.6	16
Fuel, Materials and Supplies	(16.2)	6.6
Accounts Payable	(21.6)	(3.1)
Accrued Taxes, Net	25	25.6
Other Current Assets	18.2	1.4
Other Current Liabilities	(62.7)	(35.2)
Net Cash Flows from (Used for) Operating Activities	209.1	204.8
Investing Activities
Construction Expenditures	(141.4)	(149.3)
Change in Advances to Affiliates, Net	(0.1)	(0.1)
Purchases of Investment Securities	(626)	(130.3)
Sales of Investment Securities	612.4	111.9
Acquisitions of Nuclear Fuel	(1.3)	(32.4)
Other Investing Activities	4.2	8.6
Net Cash Flows from (Used for) Investing Activities	(152.2)	(191.6)
Financing Activities
Change in Advances from Affiliates, Net	(10.7)	33.6
Retirement of Long-term Debt	(23.7)	(26.5)
Principal Payments for Finance Leases	(1.5)	(1.2)
Dividends Paid on Common Stock	(21.3)	(20)
Other Financing Activities	0.1	0.2
Net Cash Flows from (Used for) Financing Activities	(57.1)	(13.9)
Net Increase (Decrease) in Cash and Cash Equivalents	(0.2)	(0.7)
Cash and Cash Equivalents at Beginning of Period	2	2.4
Cash and Cash Equivalents at End of Period	1.8	1.7
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	44.3	43.3
Net Cash Paid (Received) for Income Taxes	0	(3.3)
Noncash Acquisitions Under Finance Leases	1.4	1.7
Construction Expenditures Included in Current Liabilities as of March 31,	67.8	80
Acquisition of Nuclear Fuel Included in Current Liabilities as of March 31,	0	1
Expected Reimbursement for Spent Nuclear Fuel Dry Cask Storage	1.3	7.9
Ohio Power Co [Member]
Operating Activities
Net Income (Loss)	75.1	128
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	70.5	63.3
Amortization Of Generation Deferrals	0	32.4
Deferred Income Taxes	12.9	10.1
Carrying Costs Income	(0.4)	(0.2)
Allowance for Equity Funds Used During Construction	(1.9)	(5.2)
Mark-to-Market of Risk Management Contracts	17.3	6.7
Property Taxes	74.4	66
Refund of Global Settlement	0	(4.1)
Reversal of a Regulatory Provision	0	(56.2)
Change in Other Noncurrent Assets	(61.5)	(7.5)
Change in Other Noncurrent Liabilities	(36.4)	17.6
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(19.9)	31.7
Fuel, Materials and Supplies	(10.2)	(3.4)
Accounts Payable	35.5	(23.9)
Accrued Taxes, Net	(141.9)	(114.4)
Other Current Assets	(2)	(7.7)
Other Current Liabilities	(8.4)	(16.2)
Net Cash Flows from (Used for) Operating Activities	3.5	117.2
Investing Activities
Construction Expenditures	(232.8)	(198.5)
Other Investing Activities	5.9	3.7
Net Cash Flows from (Used for) Investing Activities	(226.9)	(194.8)
Financing Activities
Issuance of Long-term Debt	347.1	0
Change in Advances from Affiliates, Net	(101.6)	113.5
Retirement of Long-term Debt	0	(23.4)
Principal Payments for Finance Leases	(1.2)	(0.7)
Dividends Paid on Common Stock	(21.9)	(25)
Other Financing Activities	0.4	0.5
Net Cash Flows from (Used for) Financing Activities	222.8	64.9
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	(0.6)	(12.7)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	3.7	32.5
Cash and Cash Equivalents at Beginning of Period	3.7
Cash, Cash Equivalents and Restricted Cash at End of Period	3.1	19.8
Cash and Cash Equivalents at End of Period	3.1
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	16.7	17
Net Cash Paid (Received) for Income Taxes	0	(0.2)
Noncash Acquisitions Under Finance Leases	4.3	3.2
Construction Expenditures Included in Current Liabilities as of March 31,	72.9	72.8
Public Service Co Of Oklahoma [Member]
Operating Activities
Net Income (Loss)	(10.3)	6.2
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	44.7	43.5
Deferred Income Taxes	(5.3)	(5.8)
Allowance for Equity Funds Used During Construction	(1)	(0.1)
Mark-to-Market of Risk Management Contracts	9.5	5.1
Property Taxes	(29.8)	(29.9)
Deferred Fuel Over/Under-Recovery, Net	4.1	(2.4)
Change in Other Noncurrent Assets	(0.1)	8
Change in Other Noncurrent Liabilities	4.2	(0.7)
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	0.9	2
Fuel, Materials and Supplies	(8.5)	3.2
Accounts Payable	(39.1)	(23.3)
Accrued Taxes, Net	25.1	25.3
Other Current Assets	(1.7)	(3.8)
Other Current Liabilities	(7.2)	4.4
Net Cash Flows from (Used for) Operating Activities	(14.5)	31.7
Investing Activities
Construction Expenditures	(96.5)	(70.7)
Change in Advances to Affiliates, Net	38.8	0
Other Investing Activities	1.6	0.4
Net Cash Flows from (Used for) Investing Activities	(56.1)	(70.3)
Financing Activities
Issuance of Long-term Debt	0	99.9
Change in Advances from Affiliates, Net	70.9	(50.3)
Retirement of Long-term Debt	(0.1)	(0.1)
Principal Payments for Finance Leases	(0.8)	(0.7)
Dividends Paid on Common Stock	0	(11.3)
Other Financing Activities	0.2	0.6
Net Cash Flows from (Used for) Financing Activities	70.2	38.1
Net Increase (Decrease) in Cash and Cash Equivalents	(0.4)	(0.5)
Cash and Cash Equivalents at Beginning of Period	1.5	2
Cash and Cash Equivalents at End of Period	1.1	1.5
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	16.7	10.9
Net Cash Paid (Received) for Income Taxes	0	0.6
Noncash Acquisitions Under Finance Leases	0.9	1.1
Construction Expenditures Included in Current Liabilities as of March 31,	30.8	15.6
Southwestern Electric Power Co [Member]
Operating Activities
Net Income (Loss)	16.1	29
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	67.3	62.1
Deferred Income Taxes	(9.2)	(2.5)
Allowance for Equity Funds Used During Construction	(1.4)	(1.8)
Mark-to-Market of Risk Management Contracts	3.9	2.3
Property Taxes	(49)	(48.9)
Deferred Fuel Over/Under-Recovery, Net	21	10.3
Change in Other Noncurrent Assets	(4)	2.9
Change in Other Noncurrent Liabilities	9.8	7.9
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	11.3	6.3
Fuel, Materials and Supplies	(7.6)	(16.2)
Accounts Payable	(31.2)	(55)
Accrued Taxes, Net	51.2	52.7
Accrued Interest	(12.7)	(12.7)
Other Current Assets	(4)	(10)
Other Current Liabilities	(35.7)	(17)
Net Cash Flows from (Used for) Operating Activities	25.8	9.4
Investing Activities
Construction Expenditures	(122.4)	(86.6)
Change in Advances to Affiliates, Net	0	81.4
Other Investing Activities	0.8	(3.1)
Net Cash Flows from (Used for) Investing Activities	(121.6)	(8.3)
Financing Activities
Change in Short-term Debt with Original Maturities less than 90 Days, Net	12.2	0
Change in Advances from Affiliates, Net	88.2	74
Retirement of Long-term Debt	(1.6)	(55.1)
Principal Payments for Finance Leases	(2.7)	(2.7)
Dividends Paid on Common Stock	0	(18.7)
Dividends Paid on Common Stock	(0.7)	(1.1)
Other Financing Activities	0.2	0.1
Net Cash Flows from (Used for) Financing Activities	95.6	(3.5)
Net Increase (Decrease) in Cash and Cash Equivalents	(0.2)	(2.4)
Cash and Cash Equivalents at Beginning of Period	1.6	24.5
Cash and Cash Equivalents at End of Period	1.4	22.1
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	40.7	40.5
Net Cash Paid (Received) for Income Taxes	0	0.2
Noncash Acquisitions Under Finance Leases	3	0.8
Construction Expenditures Included in Current Liabilities as of March 31,	45.2	44.8
Retained Earnings [Member]
Supplementary Information
Stockholders' Equity, Other	0	62.1
Retained Earnings [Member] | AEP Texas Inc. [Member]
Operating Activities
Net Income (Loss)	47.6	34.4
Retained Earnings [Member] | AEP Transmission Co [Member]
Operating Activities
Net Income (Loss)	117.8	104.3
Retained Earnings [Member] | Appalachian Power Co [Member]
Operating Activities
Net Income (Loss)	115.3	133.7
Retained Earnings [Member] | Indiana Michigan Power Co [Member]
Operating Activities
Net Income (Loss)	92.3	98.9
Retained Earnings [Member] | Ohio Power Co [Member]
Operating Activities
Net Income (Loss)	75.1	128
Retained Earnings [Member] | Public Service Co Of Oklahoma [Member]
Operating Activities
Net Income (Loss)	$ (10.3)	$ 6.2

Significant Accounting Matters

Significant Accounting Matters	3 Months Ended
	Mar. 31, 2020
Significant Accounting Matters	SIGNIFICANT ACCOUNTING MATTERS The disclosures in this note apply to all Registrants unless indicated otherwise. General The unaudited condensed financial statements and footnotes were prepared in accordance with GAAP for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X of the SEC. Accordingly, they do not include all of the information and footnotes required by GAAP for complete annual financial statements. In the opinion of management, the unaudited condensed interim financial statements reflect all normal and recurring accruals and adjustments necessary for a fair statement of the net income, financial position and cash flows for the interim periods for each Registrant. Net income for the three months ended March 31, 2020 is not necessarily indicative of results that may be expected for the year ending December 31, 2020 . The condensed financial statements are unaudited and should be read in conjunction with the audited 2019 financial statements and notes thereto, which are included in the Registrants’ Annual Reports on Form 10-K as filed with the SEC on February 20, 2020 . COVID-19 In March 2020, COVID-19 was declared a pandemic by the World Health Organization and the Centers for Disease Control and Prevention. Its rapid spread around the world and throughout the United States prompted many countries, including the United States, to institute restrictions on travel, public gatherings and certain business operations. These restrictions significantly disrupted economic activity in AEP’s service territory and could reduce future demand for energy, particularly from commercial and industrial customers. The Registrants are taking steps to mitigate the potential risks to customers, suppliers and employees posed by the spread of COVID-19. As of March 31, 2020 and through the date of this report, the Registrants assessed certain accounting matters that require consideration of forecasted financial information, including, but not limited to, the allowance for credit losses and the carrying value of long-lived assets. While there were not any impairments or significant increases in credit allowances resulting from these assessments as of and for the quarter ended March 31, 2020, the ultimate impact of COVID-19 also depends on factors beyond management’s knowledge or control, including the duration and severity of this outbreak as well as third-party actions taken to contain its spread and mitigate its public health effects. Therefore, management cannot estimate the potential future impact to financial position, results of operations and cash flows, but the impacts could be material. 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 awards. The following table presents AEP’s basic and diluted EPS calculations included on the statements of income: Three Months Ended March 31, 2020 2019 (in millions, except per share data) $/share $/share Earnings Attributable to AEP Common Shareholders $ 495.2 $ 572.8 Weighted Average Number of Basic Shares Outstanding 494.6 $ 1.00 493.3 $ 1.16 Weighted Average Dilutive Effect of Stock-Based Awards 2.0 — 1.2 — Weighted Average Number of Diluted Shares Outstanding 496.6 $ 1.00 494.5 $ 1.16 Equity Units issued in March 2019 are potentially dilutive securities but were excluded from the calculation of diluted EPS for the three months ended March 31, 2020 and 2019 , as the dilutive stock price threshold was not met. See Note 12 - Financing Activities for more information related to Equity Units. There were 697 thousand and 0 antidilutive shares outstanding as of March 31, 2020 and 2019 , respectively. The antidilutive shares were excluded from the calculation of diluted EPS. Restricted Cash (Applies to AEP, AEP Texas and APCo) Restricted Cash primarily included funds held by trustee for the payment of securitization bonds and contractually restricted deposits held for the future payment of the remaining construction activities at Santa Rita East. 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 statements of cash flows: March 31, 2020 AEP AEP Texas APCo (in millions) Cash and Cash Equivalents $ 1,554.6 $ 0.1 $ 2.8 Restricted Cash 116.2 100.1 15.7 Total Cash, Cash Equivalents and Restricted Cash $ 1,670.8 $ 100.2 $ 18.5 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 SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES 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.

New Accounting Standards

New Accounting Standards	3 Months Ended
	Mar. 31, 2020
New Accounting Standards	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. The new accounting guidance is effective for all entities as of March 12, 2020 through December 31, 2022. The amendments may be applied to contract modifications as of any date from the beginning of an interim period that includes or is subsequent to March 12, 2020, or prospectively from a date within an interim period that includes or is subsequent to March 12, 2020, up to the date that the financial statements are available to be issued. The amendments may be applied to eligible hedging relationships existing as of the beginning of the interim period that includes March 12, 2020 and to new eligible hedging relationships entered into after the beginning of the interim period that includes March 12, 2020. The one-time election to sell, transfer, or both sell and transfer debt securities classified as held-to-maturity may be made at any time after March 12, 2020 but no later than December 31, 2022. Management has yet to apply the amendments in the new standard to any contract modifications, hedging relationships, or debt securities. Management is analyzing the impact of this new standard and at this time, cannot estimate the impact of adoption on results of operations, financial position or cash flows.

Comprehensive Income

Comprehensive Income	3 Months Ended
	Mar. 31, 2020
Comprehensive Income	COMPREHENSIVE INCOME The disclosures in this note apply to all Registrants except AEPTCo unless indicated otherwise. Presentation of Comprehensive Income The following tables provide the components of changes in AOCI and details of reclassifications from AOCI. The amortization of pension and OPEB AOCI components are included in the computation of net periodic pension and OPEB costs. See Note 7 - Benefit Plans for additional details. AEP Cash Flow Hedges Pension Three Months Ended March 31, 2020 Commodity Interest Rate and OPEB Total (in millions) Balance in AOCI as of December 31, 2019 $ (103.5 ) $ (11.5 ) $ (32.7 ) $ (147.7 ) Change in Fair Value Recognized in AOCI (65.3 ) (42.7 ) (a) — (108.0 ) Amount of (Gain) Loss Reclassified from AOCI Generation & Marketing Revenues (a) (0.1 ) — — (0.1 ) Purchased Electricity for Resale (b) 51.1 — — 51.1 Interest Expense (b) — 0.9 — 0.9 Amortization of Prior Service Cost (Credit) — — (4.9 ) (4.9 ) Amortization of Actuarial (Gains) Losses — — 2.6 2.6 Reclassifications from AOCI, before Income Tax (Expense) Benefit 51.0 0.9 (2.3 ) 49.6 Income Tax (Expense) Benefit 10.7 0.2 (0.5 ) 10.4 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 40.3 0.7 (1.8 ) 39.2 Net Current Period Other Comprehensive Income (Loss) (25.0 ) (42.0 ) (1.8 ) (68.8 ) Balance in AOCI as of March 31, 2020 $ (128.5 ) $ (53.5 ) $ (34.5 ) $ (216.5 ) Cash Flow Hedges Pension Three Months Ended March 31, 2019 Commodity Interest Rate and OPEB Total (in millions) Balance in AOCI as of December 31, 2018 $ (23.0 ) $ (12.6 ) $ (84.8 ) $ (120.4 ) Change in Fair Value Recognized in AOCI (38.8 ) — — (38.8 ) Amount of (Gain) Loss Reclassified from AOCI Purchased Electricity for Resale (b) 12.3 — — 12.3 Interest Expense (b) — 0.2 — 0.2 Amortization of Prior Service Cost (Credit) — — (4.8 ) (4.8 ) Amortization of Actuarial (Gains) Losses — — 3.0 3.0 Reclassifications from AOCI, before Income Tax (Expense) Benefit 12.3 0.2 (1.8 ) 10.7 Income Tax (Expense) Benefit 2.6 — (0.4 ) 2.2 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 9.7 0.2 (1.4 ) 8.5 Net Current Period Other Comprehensive Income (Loss) (29.1 ) 0.2 (1.4 ) (30.3 ) Balance in AOCI as of March 31, 2019 $ (52.1 ) $ (12.4 ) $ (86.2 ) $ (150.7 ) AEP Texas Cash Flow Hedge – Pension Three Months Ended March 31, 2020 Interest Rate and OPEB Total (in millions) Balance in AOCI as of December 31, 2019 $ (3.4 ) $ (9.4 ) $ (12.8 ) Change in Fair Value Recognized in AOCI — — — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 0.4 — 0.4 Reclassifications from AOCI, before Income Tax (Expense) Benefit 0.4 — 0.4 Income Tax (Expense) Benefit 0.1 — 0.1 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 0.3 — 0.3 Net Current Period Other Comprehensive Income (Loss) 0.3 — 0.3 Balance in AOCI as of March 31, 2020 $ (3.1 ) $ (9.4 ) $ (12.5 ) Cash Flow Hedge – Pension Three Months Ended March 31, 2019 Interest Rate and OPEB Total (in millions) Balance in AOCI as of December 31, 2018 $ (4.4 ) $ (10.7 ) $ (15.1 ) Change in Fair Value Recognized in AOCI — — — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 0.4 — 0.4 Reclassifications from AOCI, before Income Tax (Expense) Benefit 0.4 — 0.4 Income Tax (Expense) Benefit 0.1 — 0.1 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 0.3 — 0.3 Net Current Period Other Comprehensive Income (Loss) 0.3 — 0.3 Balance in AOCI as of March 31, 2019 $ (4.1 ) $ (10.7 ) $ (14.8 ) APCo Cash Flow Hedge – Pension Three Months Ended March 31, 2020 Interest Rate and OPEB Total (in millions) Balance in AOCI as of December 31, 2019 $ 0.9 $ 4.1 $ 5.0 Change in Fair Value Recognized in AOCI (3.9 ) — (3.9 ) Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (0.4 ) — (0.4 ) Amortization of Prior Service Cost (Credit) — (1.3 ) (1.3 ) Amortization of Actuarial (Gains) Losses — 0.1 0.1 Reclassifications from AOCI, before Income Tax (Expense) Benefit (0.4 ) (1.2 ) (1.6 ) Income Tax (Expense) Benefit (0.1 ) (0.3 ) (0.4 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (0.3 ) (0.9 ) (1.2 ) Net Current Period Other Comprehensive Income (Loss) (4.2 ) (0.9 ) (5.1 ) Balance in AOCI as of March 31, 2020 $ (3.3 ) $ 3.2 $ (0.1 ) Cash Flow Hedge – Pension Three Months Ended March 31, 2019 Interest Rate and OPEB Total (in millions) Balance in AOCI as of December 31, 2018 $ 1.8 $ (6.8 ) $ (5.0 ) Change in Fair Value Recognized in AOCI — — — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (0.3 ) — (0.3 ) Amortization of Prior Service Cost (Credit) — (1.3 ) (1.3 ) Amortization of Actuarial (Gains) Losses — 0.5 0.5 Reclassifications from AOCI, before Income Tax (Expense) Benefit (0.3 ) (0.8 ) (1.1 ) Income Tax (Expense) Benefit (0.1 ) (0.2 ) (0.3 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (0.2 ) (0.6 ) (0.8 ) Net Current Period Other Comprehensive Income (Loss) (0.2 ) (0.6 ) (0.8 ) Balance in AOCI as of March 31, 2019 $ 1.6 $ (7.4 ) $ (5.8 ) I&M Cash Flow Hedge – Pension Three Months Ended March 31, 2020 Interest Rate and OPEB Total (in millions) Balance in AOCI as of December 31, 2019 $ (9.9 ) $ (1.7 ) $ (11.6 ) Change in Fair Value Recognized in AOCI — — — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 0.5 — 0.5 Amortization of Prior Service Cost (Credit) — (0.2 ) (0.2 ) Amortization of Actuarial (Gains) Losses — 0.2 0.2 Reclassifications from AOCI, before Income Tax (Expense) Benefit 0.5 — 0.5 Income Tax (Expense) Benefit 0.1 — 0.1 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 0.4 — 0.4 Net Current Period Other Comprehensive Income (Loss) 0.4 — 0.4 Balance in AOCI as of March 31, 2020 $ (9.5 ) $ (1.7 ) $ (11.2 ) Cash Flow Hedge – Pension Three Months Ended March 31, 2019 Interest Rate and OPEB Total (in millions) Balance in AOCI as of December 31, 2018 $ (11.5 ) $ (2.3 ) $ (13.8 ) Change in Fair Value Recognized in AOCI — — — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 0.5 — 0.5 Amortization of Prior Service Cost (Credit) — (0.2 ) (0.2 ) Amortization of Actuarial (Gains) Losses — 0.2 0.2 Reclassifications from AOCI, before Income Tax (Expense) Benefit 0.5 — 0.5 Income Tax (Expense) Benefit 0.1 — 0.1 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 0.4 — 0.4 Net Current Period Other Comprehensive Income (Loss) 0.4 — 0.4 Balance in AOCI as of March 31, 2019 $ (11.1 ) $ (2.3 ) $ (13.4 ) OPCo Cash Flow Hedge – Three Months Ended March 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 March 31, 2020 $ — Cash Flow Hedge – Three Months Ended March 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) (0.4 ) Reclassifications from AOCI, before Income Tax (Expense) Benefit (0.4 ) Income Tax (Expense) Benefit (0.1 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (0.3 ) Net Current Period Other Comprehensive Income (Loss) (0.3 ) Balance in AOCI as of March 31, 2019 $ 0.7 PSO Cash Flow Hedge – Three Months Ended March 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) (0.3 ) Reclassifications from AOCI, before Income Tax (Expense) Benefit (0.3 ) Income Tax (Expense) Benefit (0.1 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (0.2 ) Net Current Period Other Comprehensive Income (Loss) (0.2 ) Balance in AOCI as of March 31, 2020 $ 0.9 Cash Flow Hedge – Three Months Ended March 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) (0.3 ) Reclassifications from AOCI, before Income Tax (Expense) Benefit (0.3 ) Income Tax (Expense) Benefit (0.1 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (0.2 ) Net Current Period Other Comprehensive Income (Loss) (0.2 ) Balance in AOCI as of March 31, 2019 $ 1.9 SWEPCo Cash Flow Hedge – Pension Three Months Ended March 31, 2020 Interest Rate and OPEB Total (in millions) Balance in AOCI as of December 31, 2019 $ (1.8 ) $ 0.5 $ (1.3 ) Change in Fair Value Recognized in AOCI — — — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 0.5 — 0.5 Amortization of Prior Service Cost (Credit) — (0.5 ) (0.5 ) Reclassifications from AOCI, before Income Tax (Expense) Benefit 0.5 (0.5 ) — Income Tax (Expense) Benefit 0.1 (0.1 ) — Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 0.4 (0.4 ) — Net Current Period Other Comprehensive Income (Loss) 0.4 (0.4 ) — Balance in AOCI as of March 31, 2020 $ (1.4 ) $ 0.1 $ (1.3 ) Cash Flow Hedge – Pension Three Months Ended March 31, 2019 Interest Rate and OPEB Total (in millions) Balance in AOCI as of December 31, 2018 $ (3.3 ) $ (2.1 ) $ (5.4 ) Change in Fair Value Recognized in AOCI — — — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 0.5 — 0.5 Amortization of Prior Service Cost (Credit) — (0.5 ) (0.5 ) Amortization of Actuarial (Gains) Losses — 0.1 0.1 Reclassifications from AOCI, before Income Tax (Expense) Benefit 0.5 (0.4 ) 0.1 Income Tax (Expense) Benefit 0.1 (0.1 ) — Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 0.4 (0.3 ) 0.1 Net Current Period Other Comprehensive Income (Loss) 0.4 (0.3 ) 0.1 Balance in AOCI as of March 31, 2019 $ (2.9 ) $ (2.4 ) $ (5.3 ) (a) The change in fair value includes $5 million related to AEP's investment in joint venture wind farms acquired as part of the purchase of Sempra Renewables LLC for the three months ended March 31, 2020. (b)

Rate Matters

Rate Matters	3 Months Ended
	Mar. 31, 2020
Rate Matters	RATE MATTERS The disclosures in this note apply to all Registrants unless indicated otherwise. As discussed in the 2019 Annual Report, the Registrants are involved in rate and regulatory proceedings at the FERC and their state commissions. The Rate Matters note within the 2019 Annual Report should be read in conjunction with this report to gain a complete understanding of material rate matters still pending that could impact net income, cash flows and possibly financial condition. The following discusses ratemaking developments in 2020 and updates the 2019 Annual Report. Regulated Generating Units to be Retired (Applies to AEP, PSO and SWEPCo) In September 2018, management announced that the Oklaunion Power Station is probable of abandonment and is expected to be retired by October 2020. 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. In March 2020, management announced plans to accelerate the expected retirement date to the end of September 2021. The table below summarizes the plant investment and their cost of removal, currently being recovered, as well as the regulatory assets for accelerated depreciation for the generating units as of March 31, 2020 . Plant Gross Investment Accumulated Depreciation Net Investment Accelerated Depreciation Regulatory Asset Materials and Supplies Cost of Removal Regulatory Liability Expected Retirement Date Remaining Recovery Period (dollars in millions) Oklaunion Power Station $ 106.8 $ 92.6 $ 14.2 $ 33.0 (a) $ 3.3 $ 5.2 2020 27 years Dolet Hills Power Station 341.4 205.0 136.4 9.1 (b) 5.8 23.7 2021 27 years (a) In October 2018, PSO changed depreciation rates to utilize the 2020 end-of-life and defer depreciation expense to a regulatory asset for the amount in excess of the previously OCC-approved depreciation rates for Oklaunion Power Station. (b) In January 2020, SWEPCo changed depreciation rates to utilize the 2026 end-of-life and defer depreciation expense to a regulatory asset for the amount in excess of the previously APSC-approved depreciation rates for Dolet Hills Power Station. In March 2020, SWEPCo changed depreciation rates again to utilize the accelerated 2021 end-of-life. 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. In March 2020, it was determined that DHLC would not proceed developing additional mining areas for future lignite extraction and management notified a substantial portion of its workforce that employment will permanently end in June 2020. Based on these actions, management has revised the estimated useful life of many of DHLC’s assets to June 2020 to coincide with the date at which extraction is expected to be discontinued. Management also revised the useful life of the Dolet Hills Power Station to September 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 pending cessation of lignite mining in June 2020. 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 Lignite Mining Agreement, DHLC bills SWEPCo its proportionate share of incurred lignite extraction and associated mining-related costs as fuel is delivered. As of March 31, 2020, DHLC has unbilled lignite inventory and fixed costs of $124 million that will be billed to SWEPCo prior to the closure of the Dolet Hills Power Station. In 2009, SWEPCo acquired interests in the Oxbow Lignite Company (Oxbow), which owns mineral rights and leases land. Under a Joint Operating Agreement pertaining to the Oxbow mineral rights and land leases, Oxbow bills SWEPCo its proportionate share of incurred costs. As of March 31, 2020, Oxbow has unbilled fixed costs of $26 million that will be billed to SWEPCo prior to the closure of the Dolet Hills Power Station. Additional operational and land-related costs are expected to be incurred by DHLC and Oxbow and billed to SWEPCo prior to the closure of the Dolet Hills Power Station and recovered through fuel clauses. If any of these costs are not recoverable, it could reduce future net income and cash flows and impact financial condition. Regulatory Assets Pending Final Regulatory Approval (Applies to all Registrants except AEPTCo) AEP March 31, December 31, 2020 2019 Noncurrent Regulatory Assets (in millions) Regulatory Assets Currently Earning a Return Plant Retirement Costs – Unrecovered Plant $ 35.2 $ 35.2 Oklaunion Power Station Accelerated Depreciation 33.0 27.4 Kentucky Deferred Purchase Power Expenses 32.9 30.2 Dolet Hills Power Station Accelerated Depreciation 9.1 — Other Regulatory Assets Pending Final Regulatory Approval 2.1 0.7 Regulatory Assets Currently Not Earning a Return Plant Retirement Costs – Asset Retirement Obligation Costs 25.9 30.1 Asset Retirement Obligation 7.7 7.2 Storm-Related Costs 7.3 7.2 Vegetation Management Program (a) 3.8 29.4 Cook Plant Study Costs (b) — 7.6 Other Regulatory Assets Pending Final Regulatory Approval 5.0 6.7 Total Regulatory Assets Pending Final Regulatory Approval (c) $ 162.0 $ 181.7 (a) In April 2020, $26 million of deferred expenses were approved for recovery. See “2019 Texas Base Rate Case” section below for additional information. (b) Approved for recovery in the first quarter of 2020 in the Indiana Base Rate Case. (c) APCo is currently in the process of retiring and replacing its Virginia jurisdictional Automated Meter Reading (AMR) meters with AMI meters. As of March 31, 2020 and December 31, 2019 , APCo has approximately $52 million and $51 million , respectively, of Virginia jurisdictional AMR meters recorded in Total Property, Plant and Equipment - Net on its balance sheets. APCo is pursuing full recovery of these assets through its Virginia depreciation rates. See “2017-2019 Virginia Triennial Review” section below for additional information. AEP Texas March 31, December 31, 2020 2019 Noncurrent Regulatory Assets (in millions) Regulatory Assets Currently Not Earning a Return Vegetation Management Program (a) $ 3.8 $ 29.4 Other Regulatory Assets Pending Final Regulatory Approval 1.5 1.4 Total Regulatory Assets Pending Final Regulatory Approval $ 5.3 $ 30.8 (a) In April 2020, $26 million of deferred expenses were approved for recovery. See “2019 Texas Base Rate Case” section below for additional information. APCo March 31, December 31, 2020 2019 Noncurrent Regulatory Assets (in millions) Regulatory Assets Currently Earning a Return Plant Retirement Costs – Materials and Supplies $ — $ 0.5 Regulatory Assets Currently Not Earning a Return Plant Retirement Costs – Asset Retirement Obligation Costs 25.9 30.1 Total Regulatory Assets Pending Final Regulatory Approval (a) $ 25.9 $ 30.6 (a) APCo is currently in the process of retiring and replacing its Virginia jurisdictional Automated Meter Reading (AMR) meters with AMI meters. As of March 31, 2020 and December 31, 2019 , APCo has approximately $52 million and $51 million , respectively, of Virginia jurisdictional AMR meters recorded in Total Property, Plant and Equipment - Net on its balance sheets. APCo is pursuing full recovery of these assets through its Virginia depreciation rates. See “2017-2019 Virginia Triennial Review” section below for additional information. I&M March 31, December 31, 2020 2019 Noncurrent Regulatory Assets (in millions) Regulatory Assets Currently Not Earning a Return Cook Plant Study Costs (a) $ — $ 7.6 Other Regulatory Assets Pending Final Regulatory Approval — 0.1 Total Regulatory Assets Pending Final Regulatory Approval $ — $ 7.7 (a) Approved for recovery in the first quarter of 2020 in the Indiana Base Rate Case. OPCo March 31, December 31, 2020 2019 Noncurrent Regulatory Assets (in millions) Regulatory Assets Currently Not Earning a Return Other Regulatory Assets Pending Final Regulatory Approval $ 0.1 $ 0.1 Total Regulatory Assets Pending Final Regulatory Approval $ 0.1 $ 0.1 PSO March 31, December 31, 2020 2019 Noncurrent Regulatory Assets (in millions) Regulatory Assets Currently Earning a Return Oklaunion Power Station Accelerated Depreciation $ 33.0 $ 27.4 Regulatory Assets Currently Not Earning a Return Storm-Related Costs 7.3 7.2 Total Regulatory Assets Pending Final Regulatory Approval $ 40.3 $ 34.6 SWEPCo March 31, December 31, 2020 2019 Noncurrent Regulatory Assets (in millions) Regulatory Assets Currently Earning a Return Plant Retirement Costs – Unrecovered Plant, Louisiana $ 35.2 $ 35.2 Dolet Hills Power Station Accelerated Depreciation 9.1 — Other Regulatory Assets Pending Final Regulatory Approval 2.2 0.2 Regulatory Assets Currently Not Earning a Return Asset Retirement Obligation - Louisiana 7.7 7.2 Other Regulatory Assets Pending Final Regulatory Approval 1.9 3.7 Total Regulatory Assets Pending Final Regulatory Approval $ 56.1 $ 46.3 If these costs are ultimately determined not to be recoverable, it could reduce future net income and cash flows and impact financial condition. COVID-19 Pandemic AEP’s electric utility operating companies have informed retail customers and state regulators that disconnections for non-payment have been temporarily suspended. These uncertain economic conditions may result in the inability of customers to pay for electric service, which could affect the collectability of the Registrants revenues and adversely affect financial results. The Registrants are currently evaluating and working with regulatory commissions on potential rate recovery for increased costs as a result of the impacts of COVID-19. If any costs related to COVID-19 are not recoverable, it could reduce future net income and cash flows and impact financial condition. The table below describes the key elements of orders received, by jurisdiction, in response to COVID-19: Company Jurisdiction Order AEP Texas, ETT, SWEPCo Texas • Established a COVID-19 Electricity Relief Program to be funded through a rider for eligible residential customers in the areas of the state open to customer choice (AEP Texas only). • Granted permission for utilities to record a regulatory asset for expenses including, but not limited to, non-payment of qualified customer bills who have been affected by the COVID-19 pandemic. APCo Virginia • Granted permission for utilities to defer expenses related to the COVID-19 pandemic. Deferral will be subject to APCo’s Virginia earnings test during the 2020-2022 Triennial period. I&M Michigan • Granted permission for utilities to defer certain expenses related to the COVID-19 pandemic. SWEPCo Arkansas • Granted permission for utilities to establish a regulatory asset to record costs resulting from the suspension of disconnections offset by any cost savings directly attributable to the suspension of disconnections or other activities during the COVID-19 pandemic. SWEPCo Louisiana • Granted permission for utilities to record a regulatory asset for expenses resulting from the suspension of disconnections and collection of late fees related to the COVID-19 pandemic. AEP Texas Rate Matters (Applies to AEP and AEP Texas) 2019 Texas Base Rate Case In May 2019, AEP Texas filed a request with the PUCT for a $56 million annual increase in rates based upon a proposed 10.5% return on common equity. The filing 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% return on common equity 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 of 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. 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 these plants at the retirement date 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 deems 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 based upon a proposed 9.9% return on common equity. The requested annual increase includes $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 APCo’s Virginia earnings. Inclusive of the $93 million expense associated with APCo’s Virginia jurisdictional retired coal-fired plants, 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 March 31, 2020 and December 31, 2019 , APCo has approximately $52 million and $51 million of Virginia jurisdictional AMR meters recorded in Total Property, Plant and Equipment - Net on its balance sheets. APCo is pursuing full recovery of these assets through its Virginia depreciation rates as discussed above. If any APCo Virginia jurisdictional costs are not recoverable or if refunds of revenues collected from customers during the triennial review period are ordered by the Virginia SCC, it could reduce future net income and cash flows and impact financial condition. 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 March 31, 2020 , AEP’s share of ETT’s cumulative revenues that are subject to review is estimated to be $1.1 billion . A base rate review could produce a refund if ETT incurs a disallowance of the transmission investment on which an interim increase was based. A revenue decrease, including a refund of interim transmission rates, could reduce future net income and cash flows and impact financial condition. Management is unable to determine a range of potential losses, if any, that are reasonably possible of occurring. In 2018, the PUCT adopted a rule requiring investor-owned utilities operating solely inside ERCOT to make periodic filings for base rate proceedings. The rule requires ETT to file for a comprehensive base rate review no later than February 1, 2021. I&M Rate Matters (Applies to AEP and I&M) 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% return on common equity. 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 authorizing a $77 million annual base rate increase based upon a return on common equity of 9.7% effective March 2020. This increase will be phased in through January 2021 with an approximate $44 million annual increase in base rates effective March 2020 and the full $77 million annual increase effective January 2021. The order approved the majority of I&M’s proposed changes in depreciation. The order also approved 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 will negatively impact I&M’s annual pretax earnings by approximately $20 million starting June 2020. In March 2020, I&M filed for rehearing as a result of the IURC’s ruling to reject I&M’s proposed re-allocation of capacity costs. Intervenors subsequently filed objections to I&M's appeal. In April 2020, I&M filed a reply to these objections on rehearing and appealed the IURC’s order. OPCo Rate Matters (Applies to AEP and OPCo) 2020 Ohio Base Rate Case In April 2020, OPCo filed a pre-filing notice stating its intent to file an application with the PUCO to adjust distribution rates. OPCo plans to file the application in May 2020 and also plans to request a temporary delay of the normal rate case proceeding due to the COVID-19 pandemic. 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. As of March 31, 2020 , the net book value of Turk Plant was $1.5 billion , before cost of removal, including materials and supplies inventory and CWIP. If certain parts of the PUCT order are overturned and if SWEPCo cannot ultimately fully recover its approximate 33% Texas jurisdictional share of the Turk Plant investment, including AFUDC, it could reduce future net income and cash flows and impact financial condition. 2016 Texas Base Rate Case In 2016, SWEPCo filed a request with the PUCT for a net increase in Texas annual revenues of $69 million based upon a 10% return on common equity. In January 2018, the PUCT issued a final order approving a net increase in Texas annual revenues of $50 million based upon a return on common equity of 9.6% , effective May 2017. The final order also included: (a) approval to recover the Texas jurisdictional share of environmental investments placed in- service, as of June 30, 2016, at various plants, including Welsh Plant, Units 1 and 3, (b) approval of recovery of, but no return on, the Texas jurisdictional share of the net book value of Welsh Plant, Unit 2, (c) approval of $2 million in additional vegetation management expenses and (d) the rejection of SWEPCo’s proposed transmission cost recovery mechanism. As a result of the final order, in 2017 SWEPCo: (a) recorded an impairment charge of $19 million , which included $7 million associated with the lack of return on Welsh Plant, Unit 2 and $12 million related to other disallowed plant investments, (b) recognized $32 million of additional revenues, for the period of May 2017 through December 2017, that was surcharged to customers in 2018 and (c) recognized an additional $7 million of expenses consisting primarily of depreciation expense and vegetation management expense, offset by the deferral of rate case expense. SWEPCo implemented new rates in February 2018 billings. The $32 million of additional 2017 revenues was collected during 2018. In March 2018, the PUCT clarified and corrected portions of the final order, without changing the overall decision or amounts of the rate change. The order has been appealed by various intervenors. If certain parts of the PUCT order are overturned, it could reduce future net income and cash flows and impact financial condition. 2018 Louisiana Formula Rate Filing In April 2018, SWEPCo filed its formula rate plan for test year 2017 with the LPSC. The filing included a net $28 million annual increase, which was effective August 2018 and included SWEPCo’s Louisiana jurisdictional share of Welsh Plant and Flint Creek Plant environmental controls. The filing also included a reduction in the federal income tax rate due to Tax Reform but did not address the return of Excess ADIT benefits to customers. In July 2018, SWEPCo made a supplemental filing to its formula rate plan with the LPSC to reduce the requested annual increase to $18 million . The difference between SWEPCo’s requested $28 million annual increase and the $18 million annual increase in the supplemental filing is primarily the result of the return of Excess ADIT benefits to customers. In October 2018, the LPSC staff issued a recommendation that SWEPCo refund $11 million of excess federal income taxes collected, as a result of Tax Reform, from January 1, 2018 through July 31, 2018. In June 2019, the LPSC staff issued its report which reaffirmed its $11 million refund recommendation. The report also contends that SWEPCo’s requested annual rate increase of $18 million , which was implemented in August 2018, is overstated by $4 million and proposes an annual rate increase of $14 million . Additionally, the report recommends SWEPCo refund the excess over-collections associated with the $4 million difference for the period of August 2018 through the implementation of new rates. In July 2019, the LPSC approved the $11 million refund. A decision by the LPSC on the remaining formula rate plan issues is expected in the second quarter of 2020. If any of these costs are not recoverable, it could reduce future net income and cash flows and impact financial condition.

Commitments, Guarantees and Con

Commitments, Guarantees and Contingencies	3 Months Ended
	Mar. 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. The Commitments, Guarantees and Contingencies note within the 2019 Annual Report should be read in conjunction with this report. GUARANTEES Liabilities for guarantees are recorded in accordance with the accounting guidance for “Guarantees.” There is no collateral held in relation to any guarantees. In the event any guarantee is drawn, there is no recourse to third-parties unless specified below. Letters of Credit (Applies to AEP, AEP Texas and OPCo) Standby letters of credit are entered into with third-parties. These letters of credit are issued in the ordinary course of business and cover items such as natural gas and electricity risk management contracts, construction contracts, insurance programs, security deposits and debt service reserves. AEP has a $4 billion revolving credit facility due in June 2022, under which up to $1.2 billion may be issued as letters of credit on behalf of subsidiaries. As of March 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 March 31, 2020 were as follows: Company Amount Maturity (in millions) AEP $ 241.2 April 2020 to March 2021 AEP Texas 2.2 July 2020 OPCo (a) 1.0 April 2021 (a) In April 2020, the maturity date was extended from April 2020 to April 2021. Guarantees of Equity Method Investees (Applies to AEP) In April 2019, AEP acquired Sempra Renewables LLC. See “Acquisitions” section of Note 6 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 March 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. 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 March 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 Potential Loss (in millions) AEP $ 48.5 AEP Texas 11.6 APCo 6.6 I&M 4.3 OPCo 7.6 PSO 4.4 SWEPCo 4.9 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. The Owner Trustee owns the Plant and leases equal portions to AEGCo and I&M. The lease is accounted for as an operating lease with the payment obligations included in the future minimum lease payments schedule earlier in this note. The lease term is for 33 years and at the end of the lease term, AEGCo and I&M have the option to renew the lease at a rate that approximates fair value. The option to renew was not included in the measurement of the lease obligation as of March 31, 2020 as the execution of the option was not reasonably certain. AEP, AEGCo and I&M have no ownership interest in the Owner Trustee and do not guarantee its debt. The future minimum lease payments for this sale-and-leaseback transaction as of March 31, 2020 were as follows: Future Minimum Lease Payments AEP (a) I&M (in millions) 2020 $ 147.8 $ 73.9 2021 147.8 73.9 2022 147.5 73.7 Total Future Minimum Lease Payments $ 443.1 $ 221.5 (a) AEP’s future minimum lease payments include equal shares from AEGCo and I&M. AEPRO Boat and Barge Leases (Applies to AEP) In 2015, AEP sold its commercial barge transportation subsidiary, AEPRO, to a nonaffiliated party. Certain boat and barge leases acquired by the nonaffiliated party are subject to an AEP guarantee in favor of the respective lessors, ensuring future payments under such leases with maturities up to 2027. As of March 31, 2020 , the maximum potential amount of future payments required under the guaranteed leases was $53 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 March 31, 2020 , AEP’s boat and barge lease guarantee liability was $4 million , of which $1 million was recorded in Other Current Liabilities and $3 million was recorded in Deferred Credits and Other Noncurrent Liabilities on AEP’s balance sheet. In February 2020, the nonaffiliated party filed Chapter 11 bankruptcy. The party entered into a restructuring support agreement and has announced it expects to continue their operations as normal. 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. 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. For remediation processes not specifically discussed, management does not anticipate that the liabilities, if any, arising from such remediation processes would have a material effect on the financial statements. Virginia House Bill 443 (Applies to AEP and APCo) In March 2020, Virginia’s Governor signed House Bill 443 (HB 443) requiring APCo to close ash disposal units at the retired Glen Lyn Station by removal of all coal combustion material. APCo’s current ARO for these units is based on closure in place and will require future revision to reflect the costs of closure by removal. As of March 31, 2020, APCo is unable to reasonably estimate this cost due to the recent passage of the legislation. Management expects to record a material revision to the ARO after engineering plans for the removal are developed later in 2020. 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 may begin deferring incurred costs on July 1, 2020 and recovering these costs through the E-RAC beginning July 1, 2022. 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. Management does not expect HB 443 to materially impact results of operations or cash flows, but does anticipate a material impact to APCo’s balance sheet. NUCLEAR CONTINGENCIES (Applies to AEP and I&M) I&M owns and operates the Cook Plant under licenses granted by the Nuclear Regulatory Commission. 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. OPERATIONAL CONTINGENCIES Rockport Plant Litigation (Applies to AEP and I&M) In 2013, the Wilmington Trust Company filed a complaint in the U.S. District Court for the Southern District of New York against AEGCo and I&M alleging that it would be unlawfully burdened by the terms of the modified NSR consent decree after the Rockport Plant, Unit 2 lease expiration in December 2022. The terms of the consent decree allow the installation of environmental emission control equipment, repowering, refueling or retirement of the unit. The plaintiffs seek a judgment declaring that the defendants breached the lease, must satisfy obligations related to installation of emission control equipment and indemnify the plaintiffs. The New York court granted a motion to transfer this case to the U.S. District Court for the Southern District of Ohio. AEGCo and I&M sought and were granted dismissal by the U.S. District Court for the Southern District of Ohio of certain of the plaintiffs’ claims, including claims for compensatory damages, breach of contract, breach of the implied covenant of good faith and fair dealing and indemnification of costs. Plaintiffs voluntarily dismissed the surviving claims that AEGCo and I&M failed to exercise prudent utility practices with prejudice, and the court issued a final judgment. The plaintiffs subsequently filed an appeal in the U.S. Court of Appeals for the Sixth Circuit. In 2017, the U.S. Court of Appeals for the Sixth Circuit issued an opinion and judgment affirming the district court’s dismissal of the owners’ breach of good faith and fair dealing claim as duplicative of the breach of contract claims, reversing the district court’s dismissal of the breach of contract claims and remanding the case for further proceedings. Thereafter, AEP filed a motion with the U.S. District Court for the Southern District of Ohio in the original NSR litigation, seeking to modify the consent decree. The district court granted the owners’ unopposed motion to stay the lease litigation to afford time for resolution of AEP’s motion to modify the consent decree. The consent decree was modified based on an agreement among the parties in July 2019. As part of the modification to the consent decree, I&M agreed to provide an additional $7.5 million to citizens’ groups and the states for environmental mitigation projects. As joint owners in the Rockport Plant, the $7.5 million payment was shared between AEGCo and I&M based on the joint ownership agreement. The district court entered a stay that expired in February 2020. Settlement negotiations are continuing, and the parties filed a joint proposed case schedule in February 2020. See “Modification of the New Source Review Litigation Consent Decree” section of Management’s Discussion and Analysis of Financial Condition and Results of Operations for additional information. Management will continue to defend against the claims. Given that the district court dismissed plaintiffs’ claims seeking compensatory relief as premature, and that plaintiffs have yet to present a methodology for determining or any analysis supporting any alleged damages, management cannot determine a range of potential losses that is reasonably possible of occurring. Patent Infringement Complaint (Applies to AEP, AEP Texas and SWEPCo) In July 2019, Midwest Energy Emissions Corporation and MES Inc. (collectively, the plaintiffs) filed a patent infringement complaint against various parties, including AEP Texas, AGR, Cardinal Operating Company and SWEPCo (collectively, the AEP Defendants). The complaint alleges that the AEP Defendants infringed two patents owned by the plaintiffs by using specific processes for mercury control at certain coal-fired generating stations. The complaint seeks injunctive relief and damages. Management will continue to defend against the claims. Management is unable to determine a range of potential losses that is reasonably possible of occurring. Claims Challenging Transition of American Electric Power System Retirement Plan to Cash Balance Formula The American Electric Power System Retirement Plan (the Plan) has received a letter written on behalf of four participants (the Claimants) making a claim for additional plan benefits and purporting to advance such claims on behalf of a class. When the Plan’s benefit formula was changed in the year 2000, AEP provided a special provision for employees hired before January 1, 2001, allowing them to continue benefit accruals under the then benefit formula for a full 10 years alongside of the new cash balance benefit formula then being implemented. Employees who were hired on or after January 1, 2001 accrued benefits only under the new cash balance benefit formula. The Claimants have asserted claims that (a) the Plan violates the requirements under the Employee Retirement Income Security Act (ERISA) intended to preclude back-loading the accrual of benefits to the end of a participant’s career; (b) the Plan violates the age discrimination prohibitions of ERISA and the Age Discrimination in Employment Act (ADEA); and (c) the company failed to provide required notice regarding the changes to the Plan. AEP has responded to the Claimants providing a reasoned explanation for why each of their claims have been denied, and the denial to those claims have been appealed to the AEP System Retirement Plan Appeal Committee. Management will continue to defend against the claims. Management is unable to determine a range of potential losses that are reasonably possible of occurring.

Acquisitions and Impairments

Acquisitions and Impairments	3 Months Ended
	Mar. 31, 2020
Acquisitions and Impairments	ACQUISITIONS The disclosures in this note apply to AEP unless indicated otherwise. 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 . 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. 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 March 31, 2020 , the maximum potential amount of future payments associated with these guarantees was $175 million , with the last guarantee expiring in December 2037. The non-contingent liability recorded associated with these guarantees was $33 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.

Benefit Plans

Benefit Plans	3 Months Ended
	Mar. 31, 2020
Benefit Plans	BENEFIT PLANS The disclosures in this note apply to all Registrants except AEPTCo unless indicated otherwise. AEP sponsors a qualified pension plan and two unfunded nonqualified pension plans. Substantially all AEP employees are covered by the qualified plan or both the qualified and a nonqualified pension plan. AEP also sponsors OPEB plans to provide health and life insurance benefits for retired employees. 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 Three Months Ended March 31, Three Months Ended March 31, 2020 2019 2020 2019 (in millions) Service Cost $ 28.0 $ 23.9 $ 2.5 $ 2.4 Interest Cost 42.0 51.1 9.9 12.6 Expected Return on Plan Assets (66.2 ) (74.0 ) (23.9 ) (23.4 ) Amortization of Prior Service Credit — — (17.4 ) (17.3 ) Amortization of Net Actuarial Loss 23.4 14.4 1.5 5.5 Net Periodic Benefit Cost (Credit) $ 27.2 $ 15.4 $ (27.4 ) $ (20.2 ) AEP Texas Pension Plans OPEB Three Months Ended March 31, Three Months Ended March 31, 2020 2019 2020 2019 (in millions) Service Cost $ 2.6 $ 2.1 $ 0.2 $ 0.2 Interest Cost 3.5 4.4 0.8 1.0 Expected Return on Plan Assets (5.7 ) (6.4 ) (2.0 ) (2.0 ) Amortization of Prior Service Credit — — (1.4 ) (1.5 ) Amortization of Net Actuarial Loss 1.9 1.2 0.1 0.5 Net Periodic Benefit Cost (Credit) $ 2.3 $ 1.3 $ (2.3 ) $ (1.8 ) APCo Pension Plans OPEB Three Months Ended March 31, Three Months Ended March 31, 2020 2019 2020 2019 (in millions) Service Cost $ 2.6 $ 2.4 $ 0.3 $ 0.3 Interest Cost 5.1 6.3 1.6 2.2 Expected Return on Plan Assets (8.4 ) (9.4 ) (3.6 ) (3.7 ) Amortization of Prior Service Credit — — (2.5 ) (2.5 ) Amortization of Net Actuarial Loss 2.8 1.8 0.2 0.9 Net Periodic Benefit Cost (Credit) $ 2.1 $ 1.1 $ (4.0 ) $ (2.8 ) I&M Pension Plans OPEB Three Months Ended March 31, Three Months Ended March 31, 2020 2019 2020 2019 (in millions) Service Cost $ 3.9 $ 3.4 $ 0.3 $ 0.3 Interest Cost 4.9 6.0 1.2 1.5 Expected Return on Plan Assets (8.3 ) (9.2 ) (2.9 ) (2.8 ) Amortization of Prior Service Credit — — (2.4 ) (2.4 ) Amortization of Net Actuarial Loss 2.7 1.6 0.2 0.7 Net Periodic Benefit Cost (Credit) $ 3.2 $ 1.8 $ (3.6 ) $ (2.7 ) OPCo Pension Plans OPEB Three Months Ended March 31, Three Months Ended March 31, 2020 2019 2020 2019 (in millions) Service Cost $ 2.4 $ 2.0 $ 0.2 $ 0.2 Interest Cost 3.9 4.7 1.0 1.4 Expected Return on Plan Assets (6.6 ) (7.3 ) (2.6 ) (2.7 ) Amortization of Prior Service Credit — — (1.8 ) (1.7 ) Amortization of Net Actuarial Loss 2.1 1.3 0.2 0.6 Net Periodic Benefit Cost (Credit) $ 1.8 $ 0.7 $ (3.0 ) $ (2.2 ) PSO Pension Plans OPEB Three Months Ended March 31, Three Months Ended March 31, 2020 2019 2020 2019 (in millions) Service Cost $ 1.8 $ 1.6 $ 0.2 $ 0.2 Interest Cost 2.1 2.6 0.5 0.7 Expected Return on Plan Assets (3.6 ) (4.1 ) (1.3 ) (1.3 ) Amortization of Prior Service Credit — — (1.1 ) (1.1 ) Amortization of Net Actuarial Loss 1.2 0.8 0.1 0.3 Net Periodic Benefit Cost (Credit) $ 1.5 $ 0.9 $ (1.6 ) $ (1.2 ) SWEPCo Pension Plans OPEB Three Months Ended March 31, Three Months Ended March 31, 2020 2019 2020 2019 (in millions) Service Cost $ 2.5 $ 2.1 $ 0.2 $ 0.2 Interest Cost 2.5 3.1 0.6 0.8 Expected Return on Plan Assets (3.9 ) (4.4 ) (1.5 ) (1.5 ) Amortization of Prior Service Credit — — (1.3 ) (1.3 ) Amortization of Net Actuarial Loss 1.4 0.9 0.1 0.3 Net Periodic Benefit Cost (Credit) $ 2.5 $ 1.7 $ (1.9 ) $ (1.5 )

Business Segments

Business Segments	3 Months Ended
	Mar. 31, 2020
Business Segments	BUSINESS SEGMENTS The disclosures in this note apply to all Registrants unless indicated otherwise. AEP’s Reportable Segments AEP’s primary business is the generation, transmission and distribution of electricity. Within its Vertically Integrated Utilities segment, AEP centrally dispatches generation assets and manages its overall utility operations on an integrated basis because of the substantial impact of cost-based rates and regulatory oversight. Intersegment sales and transfers are generally based on underlying contractual arrangements and agreements. AEP’s reportable segments and their related business activities are outlined below: Vertically Integrated Utilities • Generation, transmission and distribution of electricity for sale to retail and wholesale customers through assets owned and operated by AEGCo, APCo, I&M, KGPCo, KPCo, PSO, SWEPCo and WPCo. Transmission and Distribution Utilities • Transmission and distribution of electricity for sale to retail and wholesale customers through assets owned and operated by AEP Texas and OPCo. • OPCo purchases energy and capacity to serve SSO customers and provides transmission and distribution services for all connected load. AEP Transmission Holdco • Development, construction and operation of transmission facilities through investments in AEPTCo. These investments have FERC-approved ROEs. • Development, construction and operation of transmission facilities through investments in AEP’s transmission-only joint ventures. These investments have PUCT-approved or FERC-approved ROEs. Generation & Marketing • Competitive generation in ERCOT and PJM. • Contracted renewable energy investments and management services. • Marketing, risk management and retail activities in ERCOT, PJM, SPP and MISO. The remainder of AEP’s activities is presented as Corporate and Other. While not considered a reportable segment, Corporate and Other primarily includes the purchasing of receivables from certain AEP utility subsidiaries, Parent’s guarantee revenue received from affiliates, investment income, interest income, interest expense, income tax expense and other nonallocated costs. The tables below present AEP’s reportable segment income statement information for the three months ended March 31, 2020 and 2019 and reportable segment balance sheet information as of March 31, 2020 and December 31, 2019 . Three Months Ended March 31, 2020 Vertically Integrated Utilities Transmission and Distribution Utilities AEP Transmission Holdco Generation Corporate and Other (a) Reconciling Adjustments Consolidated (in millions) Revenues from: External Customers $ 2,193.0 $ 1,075.2 $ 73.1 $ 408.4 $ (2.2 ) $ — $ 3,747.5 Other Operating Segments 33.7 31.7 237.1 30.2 22.1 (354.8 ) — Total Revenues $ 2,226.7 $ 1,106.9 $ 310.2 $ 438.6 $ 19.9 $ (354.8 ) $ 3,747.5 Net Income (Loss) $ 246.3 $ 116.2 $ 141.6 $ 30.5 $ (35.3 ) $ — $ 499.3 Three Months Ended March 31, 2019 Vertically Integrated Utilities Transmission and Distribution Utilities AEP Transmission Holdco Generation Corporate and Other (a) Reconciling Adjustments Consolidated (in millions) Revenues from: External Customers $ 2,372.3 $ 1,179.8 $ 61.2 $ 439.7 $ 3.8 $ — $ 4,056.8 Other Operating Segments 31.0 42.2 195.2 42.1 21.7 (332.2 ) — Total Revenues $ 2,403.3 $ 1,222.0 $ 256.4 $ 481.8 $ 25.5 $ (332.2 ) $ 4,056.8 Net Income (Loss) $ 303.6 $ 156.5 $ 125.2 $ 39.2 $ (50.4 ) $ — $ 574.1 March 31, 2020 Vertically Integrated Utilities Transmission and Distribution Utilities AEP Transmission Holdco Generation Corporate and Other (a) Reconciling Consolidated (in millions) Total Property, Plant and Equipment $ 47,764.3 $ 20,182.8 $ 10,662.9 $ 1,753.2 $ 408.3 $ (354.5 ) (b) $ 80,417.0 Accumulated Depreciation and Amortization 14,821.8 3,964.6 464.0 116.9 187.3 (186.5 ) (b) 19,368.1 Total Property Plant and Equipment - Net $ 32,942.5 $ 16,218.2 $ 10,198.9 $ 1,636.3 $ 221.0 $ (168.0 ) (b) $ 61,048.9 Total Assets $ 41,020.5 $ 18,892.5 $ 11,484.8 $ 3,216.4 $ 7,033.6 (c) $ (3,923.8 ) (b) (d) $ 77,724.0 Long-term Debt Due Within One Year: Affiliated $ 20.0 $ — $ — $ — $ — $ (20.0 ) $ — Nonaffiliated 1,316.3 289.0 — — 504.4 (e) — 2,109.7 Long-term Debt: Affiliated 39.0 — — — — (39.0 ) — Nonaffiliated 11,641.0 6,585.5 3,600.3 — 3,956.2 (e) — 25,783.0 Total Long-term Debt $ 13,016.3 $ 6,874.5 $ 3,600.3 $ — $ 4,460.6 $ (59.0 ) $ 27,892.7 December 31, 2019 Vertically Integrated Utilities Transmission and Distribution Utilities AEP Transmission Holdco Generation Corporate and Other (a) Reconciling Consolidated (in millions) Total Property, Plant and Equipment $ 47,323.7 $ 19,773.3 $ 10,334.0 $ 1,650.8 $ 418.4 $ (354.5 ) (b) $ 79,145.7 Accumulated Depreciation and Amortization 14,580.4 3,911.2 418.9 99.0 184.5 (186.4 ) (b) 19,007.6 Total Property Plant and Equipment - Net $ 32,743.3 $ 15,862.1 $ 9,915.1 $ 1,551.8 $ 233.9 $ (168.1 ) (b) $ 60,138.1 Total Assets $ 41,228.8 $ 18,757.5 $ 11,143.5 $ 3,123.8 $ 5,440.0 (c) $ (3,801.3 ) (b) (d) $ 75,892.3 Long-term Debt Due Within One Year: Affiliated $ 20.0 $ — $ — $ — $ — $ (20.0 ) $ — Nonaffiliated 704.7 392.2 — — 501.8 (e) — 1,598.7 Long-term Debt: Affiliated 39.0 — — — — (39.0 ) — Nonaffiliated 12,162.0 6,248.1 3,593.8 — 3,122.9 (e) — 25,126.8 Total Long-term Debt $ 12,925.7 $ 6,640.3 $ 3,593.8 $ — $ 3,624.7 $ (59.0 ) $ 26,725.5 (a) Corporate and Other primarily includes the purchasing of receivables from certain AEP utility subsidiaries. This segment also includes Parent’s guarantee revenue received from affiliates, investment income, interest income, interest expense and other nonallocated costs. (b) Includes eliminations due to an intercompany finance lease. (c) Includes elimination of AEP Parent’s investments in wholly-owned subsidiary companies. (d) Reconciling Adjustments for Total Assets primarily include elimination of intercompany advances to affiliates and intercompany accounts receivable. (e) Amounts reflect the impact of fair value hedge accounting. See “Accounting for Fair Value Hedging Strategies” section of Note 10 for additional information. Registrant Subsidiaries’ Reportable Segments (Applies to all Registrant Subsidiaries except AEPTCo) The Registrant Subsidiaries each have one reportable segment, an integrated electricity generation, transmission and distribution business for APCo, I&M, PSO and SWEPCo, and an integrated electricity transmission and distribution business for AEP Texas and OPCo. Other activities are insignificant. The Registrant Subsidiaries’ operations are managed on an integrated basis because of the substantial impact of cost-based rates and regulatory oversight on the business process, cost structures and operating results. AEPTCo’s Reportable Segments AEPTCo Parent is the holding company of seven FERC-regulated transmission-only electric utilities. The seven State Transcos have been identified as operating segments of AEPTCo under the accounting guidance for “Segment Reporting.” The State Transcos business consists of developing, constructing and operating transmission facilities at the request of the RTOs in which they operate and in replacing and upgrading facilities, assets and components of the existing AEP transmission system as needed to maintain reliability standards and provide service to AEP’s wholesale and retail customers. The State Transcos are regulated for rate-making purposes exclusively by the FERC and earn revenues through tariff rates charged for the use of their electric transmission systems. AEPTCo’s Chief Operating Decision Maker makes operating decisions, allocates resources to and assesses performance based on these operating segments. The 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 three months ended March 31, 2020 and 2019 and reportable segment balance sheet information as of March 31, 2020 and December 31, 2019 . Three Months Ended March 31, 2020 State Transcos AEPTCo Parent Reconciling Adjustments AEPTCo Consolidated (in millions) Revenues from: External Customers $ 61.3 $ — $ — $ 61.3 Sales to AEP Affiliates 233.7 — — 233.7 Other Revenues 0.6 — — 0.6 Total Revenues $ 295.6 $ — $ — $ 295.6 Interest Income $ 0.2 $ 34.0 $ (33.4 ) (a) $ 0.8 Interest Expense 29.6 33.4 (33.4 ) (a) 29.6 Income Tax Expense 31.8 — — 31.8 Net Income $ 117.3 $ 0.5 (b) $ — $ 117.8 Three Months Ended March 31, 2019 State Transcos AEPTCo Parent Reconciling Adjustments AEPTCo Consolidated (in millions) Revenues from: External Customers $ 50.3 $ — $ — $ 50.3 Sales to AEP Affiliates 193.2 — — 193.2 Total Revenues $ 243.5 $ — $ — $ 243.5 Interest Income $ 0.2 $ 28.4 $ (27.9 ) (a) $ 0.7 Interest Expense 21.7 27.9 (27.9 ) (a) 21.7 Income Tax Expense 27.6 — — 27.6 Net Income $ 104.2 $ 0.1 (b) $ — $ 104.3 March 31, 2020 State Transcos AEPTCo Parent Reconciling Adjustments AEPTCo (in millions) Total Transmission Property $ 10,221.2 $ — $ — $ 10,221.2 Accumulated Depreciation and Amortization 445.8 — — 445.8 Total Transmission Property – Net $ 9,775.4 $ — $ — $ 9,775.4 Notes Receivable - Affiliated $ — $ 3,427.8 $ (3,427.8 ) (c) $ — Total Assets $ 10,150.9 $ 3,562.7 (d) $ (3,513.7 ) (e) $ 10,199.9 Total Long-term Debt $ 3,465.0 $ 3,427.8 $ (3,465.0 ) (c) $ 3,427.8 December 31, 2019 State Transcos AEPTCo Parent Reconciling Adjustments AEPTCo (in millions) 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 (a) Elimination of intercompany interest income/interest expense on affiliated debt arrangement. (b) Includes the elimination of AEPTCo Parent’s equity earnings in the State Transcos. (c) Elimination of intercompany debt. (d) Includes the elimination of AEPTCo Parent’s investments in State Transcos. (e) Primarily relates to the elimination of Notes Receivable from the State Transcos.

Derivatives and Hedging

Derivatives and Hedging	3 Months Ended
	Mar. 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: Notional Volume of Derivative Instruments March 31, 2020 Primary Risk Exposure Unit of Measure AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Commodity: Power MWhs 305.4 — 38.7 18.5 3.2 5.9 1.7 Natural Gas MMBtus 42.3 — — — — — 10.7 Heating Oil and Gasoline Gallons 5.0 1.3 0.8 0.5 1.0 0.5 0.7 Interest Rate USD $ 137.1 $ — $ — $ — $ — $ — $ — Interest Rate on Long-term Debt USD $ 650.0 $ — $ 150.0 $ — $ — $ — $ — December 31, 2019 Primary Risk Exposure Unit of Measure AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Commodity: Power MWhs 365.9 — 61.0 26.8 7.1 14.9 4.4 Natural Gas MMBtus 40.7 — — — — — 11.6 Heating Oil and Gasoline Gallons 6.9 1.8 1.1 0.6 1.4 0.7 0.9 Interest Rate USD $ 140.1 $ — $ — $ — $ — $ — $ — Interest Rate on Long-term Debt USD $ 625.0 $ — $ — $ — $ — $ — $ — Fair Value Hedging Strategies (Applies to AEP) Parent enters into interest rate derivative transactions as part of an overall strategy to manage the mix of fixed-rate and floating-rate debt. Certain interest rate derivative transactions effectively modify exposure to interest rate risk by converting a portion of fixed-rate debt to a floating-rate. Provided specific criteria are met, these interest rate derivatives may be designated as fair value hedges. Cash Flow Hedging Strategies The Registrants utilize cash flow hedges on certain derivative transactions for the purchase and sale of power (“Commodity”) in order to manage the variable price risk related to forecasted purchases and sales. Management monitors the potential impacts of commodity price changes and, where appropriate, enters into derivative transactions to protect profit margins for a portion of future electricity sales and purchases. The Registrants do not hedge all commodity price risk. The Registrants utilize a variety of interest rate derivative transactions in order to manage interest rate risk exposure. The Registrants also utilize interest rate derivative contracts to manage interest rate exposure related to future borrowings of fixed-rate debt. The Registrants do not hedge all interest rate exposure. ACCOUNTING FOR DERIVATIVE INSTRUMENTS AND THE IMPACT ON THE FINANCIAL STATEMENTS The accounting guidance for “Derivatives and Hedging” requires recognition of all qualifying derivative instruments as either assets or liabilities on the balance sheets at fair value. The fair values of derivative instruments accounted for using MTM accounting or hedge accounting are based on exchange prices and broker quotes. If a quoted market price is not available, the estimate of fair value is based on the best information available including valuation models that estimate future energy prices based on existing market and broker quotes, supply and demand market data and assumptions. In order to determine the relevant fair values of the derivative instruments, the Registrants apply valuation adjustments for discounting, liquidity and credit quality. Credit risk is the risk that a counterparty will fail to perform on the contract or fail to pay amounts due. Liquidity risk represents the risk that imperfections in the market will cause the price to vary from estimated fair value based upon prevailing market supply and demand conditions. Since energy markets are imperfect and volatile, there are inherent risks related to the underlying assumptions in models used to fair value risk management contracts. Unforeseen events may cause reasonable price curves to differ from actual price curves throughout a contract’s term and at the time a contract settles. Consequently, there could be significant adverse or favorable effects on future net income and cash flows if market prices are not consistent with management’s estimates of current market consensus for forward prices in the current period. This is particularly true for longer term contracts. Cash flows may vary based on market conditions, margin requirements and the timing of settlement of risk management contracts. According to the accounting guidance for “Derivatives and Hedging,” the Registrants reflect the fair values of derivative instruments subject to netting agreements with the same counterparty net of related cash collateral. For certain risk management contracts, the Registrants are required to post or receive cash collateral based on third-party contractual agreements and risk profiles. AEP netted cash collateral received from third-parties against short-term and long-term risk management assets in the amounts of $0 and $5 million as of March 31, 2020 and December 31, 2019 , respectively. AEP netted cash collateral paid to third-parties against short-term and long-term risk management liabilities in the amounts of $76 million and $39 million as of March 31, 2020 and December 31, 2019 , respectively. APCo netted cash collateral paid to third-parties against short-term and long-term risk management liabilities in the amounts of $5 million and $1 million as of March 31, 2020 and December 31, 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 other Registrant Subsidiaries as of March 31, 2020 and December 31, 2019 . The following tables represent the gross fair value of the Registrants’ derivative activity on the balance sheets: AEP Fair Value of Derivative Instruments March 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 $ 412.7 $ 13.5 $ 4.6 $ 430.8 $ (300.4 ) $ 130.4 Long-term Risk Management Assets 331.6 13.5 52.7 397.8 (74.1 ) 323.7 Total Assets 744.3 27.0 57.3 828.6 (374.5 ) 454.1 Current Risk Management Liabilities 401.7 103.2 5.3 510.2 (353.4 ) 156.8 Long-term Risk Management Liabilities 305.9 82.9 — 388.8 (96.9 ) 291.9 Total Liabilities 707.6 186.1 5.3 899.0 (450.3 ) 448.7 Total MTM Derivative Contract Net Assets (Liabilities) $ 36.7 $ (159.1 ) $ 52.0 $ (70.4 ) $ 75.8 $ 5.4 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 Fair Value of Derivative Instruments March 31, 2020 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) Financial Position (c) (in millions) Current Risk Management Assets $ — $ — $ — Long-term Risk Management Assets — — — Total Assets — — — Current Risk Management Liabilities 1.2 (1.2 ) — Long-term Risk Management Liabilities — — — Total Liabilities 1.2 (1.2 ) — Total MTM Derivative Contract Net Assets (Liabilities) $ (1.2 ) $ 1.2 $ — December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) 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 Fair Value of Derivative Instruments March 31, 2020 Risk Management Hedging Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Interest Rate (a) Financial Position (b) Financial Position (c) (in millions) Current Risk Management Assets $ 71.1 $ 0.3 $ (53.3 ) $ 18.1 Long-term Risk Management Assets 3.5 — (3.4 ) 0.1 Total Assets 74.6 0.3 (56.7 ) 18.2 Current Risk Management Liabilities 68.3 5.3 (58.6 ) 15.0 Long-term Risk Management Liabilities 3.5 — (3.4 ) 0.1 Total Liabilities 71.8 5.3 (62.0 ) 15.1 Total MTM Derivative Contract Net Assets (Liabilities) $ 2.8 $ (5.0 ) $ 5.3 $ 3.1 December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) Financial Position (c) (in millions) Current Risk Management Assets $ 124.4 $ (85.0 ) $ 39.4 Long-term Risk Management Assets 0.9 (0.8 ) 0.1 Total Assets 125.3 (85.8 ) 39.5 Current Risk Management Liabilities 86.2 (84.3 ) 1.9 Long-term Risk Management Liabilities 0.7 (0.7 ) — Total Liabilities 86.9 (85.0 ) 1.9 Total MTM Derivative Contract Net Assets (Liabilities) $ 38.4 $ (0.8 ) $ 37.6 I&M Fair Value of Derivative Instruments March 31, 2020 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) Financial Position (c) (in millions) Current Risk Management Assets $ 42.3 $ (35.6 ) $ 6.7 Long-term Risk Management Assets 2.1 (2.0 ) 0.1 Total Assets 44.4 (37.6 ) 6.8 Current Risk Management Liabilities 38.3 (36.6 ) 1.7 Long-term Risk Management Liabilities 2.1 (2.0 ) 0.1 Total Liabilities 40.4 (38.6 ) 1.8 Total MTM Derivative Contract Net Assets $ 4.0 $ 1.0 $ 5.0 December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) Financial Position (c) (in millions) Current Risk Management Assets $ 66.9 $ (57.1 ) $ 9.8 Long-term Risk Management Assets 0.5 (0.4 ) 0.1 Total Assets 67.4 (57.5 ) 9.9 Current Risk Management Liabilities 55.2 (54.7 ) 0.5 Long-term Risk Management Liabilities 0.4 (0.4 ) — Total Liabilities 55.6 (55.1 ) 0.5 Total MTM Derivative Contract Net Assets (Liabilities) $ 11.8 $ (2.4 ) $ 9.4 OPCo Fair Value of Derivative Instruments March 31, 2020 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) Financial Position (c) (in millions) Current Risk Management Assets $ — $ — $ — Long-term Risk Management Assets — — — Total Assets — — — Current Risk Management Liabilities 9.6 (0.9 ) 8.7 Long-term Risk Management Liabilities 112.2 — 112.2 Total Liabilities 121.8 (0.9 ) 120.9 Total MTM Derivative Contract Net Assets (Liabilities) $ (121.8 ) $ 0.9 $ (120.9 ) December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) 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 Fair Value of Derivative Instruments March 31, 2020 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) Financial Position (c) (in millions) Current Risk Management Assets $ 6.7 $ (0.3 ) $ 6.4 Long-term Risk Management Assets — — — Total Assets 6.7 (0.3 ) 6.4 Current Risk Management Liabilities 0.9 (0.8 ) 0.1 Long-term Risk Management Liabilities — — — Total Liabilities 0.9 (0.8 ) 0.1 Total MTM Derivative Contract Net Assets $ 5.8 $ 0.5 $ 6.3 December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) 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 Fair Value of Derivative Instruments March 31, 2020 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) Financial Position (c) (in millions) Current Risk Management Assets $ 2.7 $ (0.1 ) $ 2.6 Long-term Risk Management Assets — — — Total Assets 2.7 (0.1 ) 2.6 Current Risk Management Liabilities 2.9 (0.7 ) 2.2 Long-term Risk Management Liabilities 2.9 — 2.9 Total Liabilities 5.8 (0.7 ) 5.1 Total MTM Derivative Contract Net Assets (Liabilities) $ (3.1 ) $ 0.6 $ (2.5 ) December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) 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’ activity of derivative risk management contracts: Amount of Gain (Loss) Recognized on Risk Management Contracts Three Months Ended March 31, 2020 Location of Gain (Loss) AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Vertically Integrated Utilities Revenues $ 0.4 $ — $ — $ — $ — $ — $ — Generation & Marketing Revenues (10.3 ) — — — — — — Electric Generation, Transmission and Distribution Revenues — — 0.2 0.1 — — — Purchased Electricity for Resale 0.1 — 0.1 — — — — Other Operation (0.2 ) (0.1 ) — — (0.1 ) — — Maintenance (0.2 ) (0.1 ) (0.1 ) — — — — Regulatory Assets (a) (33.9 ) (1.2 ) (8.9 ) (0.7 ) (18.4 ) (0.5 ) (2.0 ) Regulatory Liabilities (a) 11.2 — (7.3 ) 3.2 3.5 8.1 3.3 Total Gain (Loss) on Risk Management Contracts $ (32.9 ) $ (1.4 ) $ (16.0 ) $ 2.6 $ (15.0 ) $ 7.6 $ 1.3 Three Months Ended March 31, 2019 Location of Gain (Loss) AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Vertically Integrated Utilities Revenues $ 0.3 $ — $ — $ — $ — $ — $ — Generation & Marketing Revenues 2.7 — — — — — — Electric Generation, Transmission and Distribution Revenues — — (0.1 ) 0.3 — — 0.1 Purchased Electricity for Resale 1.4 — — — — — — Other Operation (0.4 ) (0.1 ) (0.1 ) — (0.1 ) — — Maintenance (0.5 ) (0.1 ) — — (0.1 ) — (0.1 ) Regulatory Assets (a) (6.4 ) 0.6 (2.1 ) 0.3 (8.9 ) 0.5 (0.1 ) Regulatory Liabilities (a) (22.0 ) — (31.7 ) 6.6 — 6.2 4.7 Total Gain (Loss) on Risk Management Contracts $ (24.9 ) $ 0.4 $ (34.0 ) $ 7.2 $ (9.1 ) $ 6.7 $ 4.6 (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 Liabilities Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Liabilities March 31, 2020 December 31, 2019 March 31, 2020 December 31, 2019 (in millions) Long-term Debt (a) $ (553.4 ) $ (510.8 ) $ (57.0 ) $ (14.5 ) (a) Amounts included on the balance sheets within Long-term Debt Due within One Year and Long-term Debt, respectively. The pretax effects of fair value hedge accounting on income were as follows: Three Months Ended March 31, 2020 2019 (in millions) Gain (Loss) on Interest Rate Contracts: Gain on Fair Value Hedging Instruments (a) $ 42.5 $ 11.1 Loss on Fair Value Portion of Long-term Debt (a) (42.5 ) (11.1 ) (a) Gain (Loss) is included in Interest Expense on the statements of income. Accounting for Cash Flow Hedging Strategies For cash flow hedges (i.e. hedging the exposure to variability in expected future cash flows that is attributable to a particular risk), the Registrants initially report the gain or loss on the derivative instrument as a component of Accumulated Other Comprehensive Income (Loss) on the balance sheets until the period the hedged item affects net income. Realized gains and losses on derivative contracts for the purchase and sale of power designated as cash flow hedges are included in Total Revenues or Purchased Electricity for Resale on the statements of income or in Regulatory Assets or Regulatory Liabilities on the balance sheets, depending on the specific nature of the risk being hedged. During the three months ended March 31, 2020 and 2019 , AEP applied cash flow hedging to outstanding power derivatives. During the three months ended March 31, 2020 and 2019 , 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 three months ended March 31, 2020 , AEP and APCo applied cash flow hedging to outstanding interest rate derivatives and the other Registrant Subsidiaries did not. During the three months ended March 31, 2019 , the Registrants did not apply cash flow hedging to outstanding interest rate derivatives. 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 March 31, 2020 December 31, 2019 Commodity Interest Rate Commodity Interest Rate (in millions) AOCI Gain (Loss) Net of Tax $ (128.5 ) $ (53.5 ) $ (103.5 ) $ (11.5 ) Portion Expected to be Reclassed to Net Income During the Next Twelve Months (73.2 ) (4.3 ) (51.7 ) (2.1 ) As of March 31, 2020 the maximum length of time that AEP is hedging its exposure to variability in future cash flows related to forecasted transactions is 132 months and 129 months for commodity and interest rate hedges, respectively. Impact of Cash Flow Hedges on the Registrant Subsidiaries’ Balance Sheets March 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 $ (3.1 ) $ (1.1 ) $ (3.4 ) $ (1.1 ) APCo (3.3 ) 1.1 0.9 0.9 I&M (9.5 ) (1.6 ) (9.9 ) (1.6 ) PSO 0.9 0.9 1.1 1.0 SWEPCo (1.4 ) (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 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 March 31, 2020 and December 31, 2019 , respectively. 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: March 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 $ 310.4 $ 1.6 $ 282.9 APCo 2.2 — 0.2 I&M 1.3 — 0.1 SWEPCo 5.5 — 5.5 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

Fair Value Measurements	3 Months Ended
	Mar. 31, 2020
Fair Value Measurements	FAIR VALUE MEASUREMENTS The disclosures in this note apply to all Registrants except AEPTCo unless indicated otherwise. Fair Value Hierarchy and Valuation Techniques 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 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 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. 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: March 31, 2020 December 31, 2019 Company Book Value Fair Value Book Value Fair Value (in millions) AEP (a) $ 27,892.7 $ 29,776.6 $ 26,725.5 $ 30,172.0 AEP Texas 4,445.4 4,637.3 4,558.4 4,981.5 AEPTCo 3,427.8 3,680.7 3,427.3 3,868.0 APCo 4,352.4 4,959.0 4,363.8 5,253.1 I&M 3,028.0 3,318.2 3,050.2 3,453.8 OPCo 2,429.1 2,795.3 2,082.0 2,554.3 PSO 1,386.3 1,553.9 1,386.2 1,603.3 SWEPCo 2,654.4 2,776.5 2,655.6 2,927.9 (a) The fair value amount includes debt related to AEP’s Equity Units issued in March 2019 and has a fair value of $777 million and $871 million as of March 31, 2020 and December 31, 2019 , respectively. See “Equity Units” section of Note 12 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. The following is a summary of Other Temporary Investments: March 31, 2020 Gross Gross Unrealized Unrealized Fair Other Temporary Investments Cost Gains Losses Value (in millions) Restricted Cash and Other Cash Deposits (a) $ 151.9 $ — $ — $ 151.9 Fixed Income Securities – Mutual Funds (b) 118.6 0.4 — 119.0 Equity Securities – Mutual Funds 19.3 11.2 — 30.5 Total Other Temporary Investments $ 289.8 $ 11.6 $ — $ 301.4 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: Three Months Ended March 31, 2020 2019 (in millions) Proceeds from Investment Sales $ 23.2 $ — Purchases of Investments 6.7 0.1 Gross Realized Gains on Investment Sales 2.0 — Gross Realized Losses on Investment Sales 0.1 — Fair Value Measurements of Trust Assets for Decommissioning and SNF Disposal (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 external investment managers who must comply with the guidelines and rules of the applicable regulatory authorities. The trust assets are invested to optimize the net of tax earnings of the trust giving consideration to liquidity, risk, diversification and other prudent investment objectives. I&M records securities held in these trust funds in Spent Nuclear Fuel and Decommissioning Trusts on its balance sheets. I&M records these securities at fair value. I&M classifies securities in the trust funds as available-for-sale due to their long-term purpose. Available-for-sale classification only applies to investment in debt securities in accordance with ASU 2016-01. Additionally, ASU 2016-01 requires changes in fair value of equity securities to be recognized in earnings. However, due to the regulatory treatment described below, this is not applicable for I&M’s trust fund securities. Other-than-temporary impairments for investments in debt securities are considered realized losses as a result of securities being managed by an external investment management firm. The external investment management firm makes specific investment decisions regarding the debt and equity investments held in these trusts and generally intends to sell debt securities in an unrealized loss position as part of a tax optimization strategy. Impairments reduce the cost basis of the securities which will affect any future unrealized gain or realized gain or loss due to the adjusted cost of investment. I&M records unrealized gains, unrealized losses and other-than-temporary impairments from securities in these trust funds as adjustments to the regulatory liability account for the nuclear decommissioning trust funds and to regulatory assets or liabilities for the SNF disposal trust funds in accordance with their treatment in rates. Consequently, changes in fair value of trust assets do not affect earnings or AOCI. The following is a summary of nuclear trust fund investments: March 31, 2020 December 31, 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 $ 46.9 $ — $ — $ 15.3 $ — $ — Fixed Income Securities: United States Government 1,026.1 121.4 (5.6 ) 1,112.5 55.5 (6.1 ) Corporate Debt 62.7 6.0 (1.6 ) 72.4 5.3 (1.6 ) State and Local Government 149.7 1.5 (0.2 ) 7.6 0.7 (0.2 ) Subtotal Fixed Income Securities 1,238.5 128.9 (7.4 ) 1,192.5 61.5 (7.9 ) Equity Securities - Domestic (a) 1,393.8 777.6 — 1,767.9 1,144.4 — Spent Nuclear Fuel and Decommissioning Trusts $ 2,679.2 $ 906.5 $ (7.4 ) $ 2,975.7 $ 1,205.9 $ (7.9 ) (a) Amount reported as Gross Unrealized Gains includes unrealized gains of $801 million and $1.1 billion and unrealized losses of $23 million and $5 million as of March 31, 2020 and December 31, 2019 , respectively. The following table provides the securities activity within the decommissioning and SNF trusts: Three Months Ended March 31, 2020 2019 (in millions) Proceeds from Investment Sales $ 612.4 $ 111.9 Purchases of Investments 626.0 130.3 Gross Realized Gains on Investment Sales 10.9 12.3 Gross Realized Losses on Investment Sales 17.0 13.8 The base cost of fixed income securities was $1.1 billion and $1.1 billion as of March 31, 2020 and December 31, 2019 , respectively. The base cost of equity securities was $616 million and $623 million as of March 31, 2020 and December 31, 2019 , respectively. The fair value of fixed income securities held in the nuclear trust funds, summarized by contractual maturities, as of March 31, 2020 was as follows: Fair Value of Fixed Income Securities (in millions) Within 1 year $ 238.9 After 1 year through 5 years 404.5 After 5 years through 10 years 282.5 After 10 years 312.6 Total $ 1,238.5 Fair Value Measurements of Financial Assets and Liabilities The following tables set forth, by level within the fair value hierarchy, the Registrants’ financial assets and liabilities that were accounted for at fair value on a recurring basis. As required by the accounting guidance for “Fair Value Measurements and Disclosures,” financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. Management’s assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy levels. There have not been any significant changes in management’s valuation techniques. AEP Assets and Liabilities Measured at Fair Value on a Recurring Basis March 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Other Temporary Investments Restricted Cash and Other Cash Deposits (a) $ 128.1 $ — $ — $ 23.8 $ 151.9 Fixed Income Securities – Mutual Funds 119.0 — — — 119.0 Equity Securities – Mutual Funds (b) 30.5 — — — 30.5 Total Other Temporary Investments 277.6 — — 23.8 301.4 Risk Management Assets Risk Management Commodity Contracts (c) (d) 3.7 369.8 346.1 (340.5 ) 379.1 Cash Flow Hedges: Commodity Hedges (c) — 18.7 4.2 (5.2 ) 17.7 Interest Rate Hedges — 0.3 — — 0.3 Fair Value Hedges — 57.0 — — 57.0 Total Risk Management Assets 3.7 445.8 350.3 (345.7 ) 454.1 Spent Nuclear Fuel and Decommissioning Trusts Cash and Cash Equivalents (e) 37.0 — — 9.9 46.9 Fixed Income Securities: United States Government — 1,026.1 — — 1,026.1 Corporate Debt — 62.7 — — 62.7 State and Local Government — 149.7 — — 149.7 Subtotal Fixed Income Securities — 1,238.5 — — 1,238.5 Equity Securities – Domestic (b) 1,393.8 — — — 1,393.8 Total Spent Nuclear Fuel and Decommissioning Trusts 1,430.8 1,238.5 — 9.9 2,679.2 Total Assets $ 1,712.1 $ 1,684.3 $ 350.3 $ (312.0 ) $ 3,434.7 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (d) $ 4.9 $ 410.1 $ 267.9 $ (416.3 ) $ 266.6 Cash Flow Hedges: Commodity Hedges (c) — 142.1 39.9 (5.2 ) 176.8 Interest Rate Hedges — 5.3 — — 5.3 Total Risk Management Liabilities $ 4.9 $ 557.5 $ 307.8 $ (421.5 ) $ 448.7 AEP Assets and Liabilities Measured at Fair Value on a Recurring Basis December 31, 2019 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Other Temporary Investments Restricted Cash and Other Cash Deposits (a) $ 197.6 $ — $ — $ 17.1 $ 214.7 Fixed Income Securities – Mutual Funds 123.3 — — — 123.3 Equity Securities – Mutual Funds (b) 50.5 — — — 50.5 Total Other Temporary Investments 371.4 — — 17.1 388.5 Risk Management Assets Risk Management Commodity Contracts (c) (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 Assets and Liabilities Measured at Fair Value on a Recurring Basis March 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 100.1 $ — $ — $ — $ 100.1 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) $ — $ 1.2 $ — $ (1.2 ) $ — December 31, 2019 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 154.7 $ — $ — $ — $ 154.7 APCo Assets and Liabilities Measured at Fair Value on a Recurring Basis March 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 15.7 $ — $ — $ — $ 15.7 Risk Management Assets Risk Management Commodity Contracts (c) (g) — 55.0 17.1 (54.2 ) 17.9 Cash Flow Hedges: Interest Rate Hedges — 0.3 — — 0.3 Total Risk Management Assets — 55.3 17.1 (54.2 ) 18.2 Total Assets $ 15.7 $ 55.3 $ 17.1 $ (54.2 ) $ 33.9 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 58.8 $ 10.5 $ (59.5 ) $ 9.8 Cash Flow Hedges: Interest Rate Hedges — 5.3 — — 5.3 Total Risk Management Liabilities $ — $ 64.1 $ 10.5 $ (59.5 ) $ 15.1 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 Assets and Liabilities Measured at Fair Value on a Recurring Basis March 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ 38.1 $ 4.9 $ (36.2 ) $ 6.8 Spent Nuclear Fuel and Decommissioning Trusts Cash and Cash Equivalents (e) 37.0 — — 9.9 46.9 Fixed Income Securities: United States Government — 1,026.1 — — 1,026.1 Corporate Debt — 62.7 — — 62.7 State and Local Government — 149.7 — — 149.7 Subtotal Fixed Income Securities — 1,238.5 — — 1,238.5 Equity Securities - Domestic (b) 1,393.8 — — — 1,393.8 Total Spent Nuclear Fuel and Decommissioning Trusts 1,430.8 1,238.5 — 9.9 2,679.2 Total Assets $ 1,430.8 $ 1,276.6 $ 4.9 $ (26.3 ) $ 2,686.0 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 36.2 $ 2.8 $ (37.2 ) $ 1.8 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 Assets and Liabilities Measured at Fair Value on a Recurring Basis March 31, 2020 Level 1 Level 2 Level 3 Other Total Liabilities: (in millions) Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 0.9 $ 120.9 $ (0.9 ) $ 120.9 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 Assets and Liabilities Measured at Fair Value on a Recurring Basis March 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ — $ 6.7 $ (0.3 ) $ 6.4 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 0.5 $ 0.4 $ (0.8 ) $ 0.1 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 Assets and Liabilities Measured at Fair Value on a Recurring Basis March 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ — $ 2.7 $ (0.1 ) $ 2.6 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 0.6 $ 5.2 $ (0.7 ) $ 5.1 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 March 31, 2020 maturity of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), is as follows: Level 1 matures $(1) million in periods 2021-2023; Level 2 matures $(30) million in 2020, $(9) million in periods 2021-2023 and $(1) million in periods 2024-2025; Level 3 matures $37 million in 2020, $36 million in periods 2021-2023, $25 million in periods 2024-2025 and $(20) million in periods 2026-2032. Risk management commodity contracts are substantially comprised of power contracts. (e) Amounts in “Other’’ column primarily represent accrued interest receivables from financial institutions. Level 1 amounts primarily represent investments in money market funds. (f) The December 31, 2019 maturity of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), is as follows: Level 2 matures $(7) million in 2020 and $(3) million in periods 2021-2023; Level 3 matures $96 million in 2020, $36 million in periods 2021-2023, $25 million in periods 2024-2025 and $(12) million in periods 2026-2032. Risk management commodity contracts are substantially comprised of power contracts. (g) Substantially comprised of power contracts for the Registrant Subsidiaries. The following tables set forth a reconciliation of changes in the fair value of net trading derivatives classified as Level 3 in the fair value hierarchy: Three Months Ended March 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) 0.9 (9.2 ) 0.2 (0.3 ) 8.0 1.9 Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date (a) 10.9 — — — — — Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income (c) (4.1 ) — — — — — Settlements (59.2 ) (21.9 ) (4.0 ) 2.5 (17.7 ) (5.3 ) Transfers into Level 3 (d) (e) (0.5 ) — — — — — Transfers out of Level 3 (e) 5.3 0.7 0.4 — — — Changes in Fair Value Allocated to Regulated Jurisdictions (f) (20.7 ) (0.7 ) (0.3 ) (19.5 ) 0.2 (0.5 ) Balance as of March 31, 2020 $ 42.5 $ 6.6 $ 2.1 $ (120.9 ) $ 6.3 $ (2.5 ) Three Months Ended March 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) (23.0 ) (29.0 ) — (0.4 ) 6.8 3.3 Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date (a) 8.5 — — — — — Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income (c) (15.8 ) — — — — — Settlements (54.5 ) (17.8 ) (5.1 ) 1.8 (13.0 ) (7.3 ) Transfers into Level 3 (d) (e) 0.1 — — — — — Transfers out of Level 3 (e) (1.2 ) (0.7 ) (0.4 ) — — — Changes in Fair Value Allocated to Regulated Jurisdictions (f) (7.2 ) (2.9 ) 1.0 (8.1 ) 1.1 1.7 Balance as of March 31, 2019 $ 38.1 $ 7.4 $ 4.4 $ (106.1 ) $ 4.4 $ — (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 Significant Unobservable Inputs March 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input Low High Average (c) (in millions) Energy Contracts $ 321.2 $ 284.6 Discounted Cash Flow Forward Market Price (a) $ (0.05 ) $ 135.24 $ 29.17 Natural Gas Contracts — 5.1 Discounted Cash Flow Forward Market Price (b) 1.37 2.51 2.13 FTRs 29.1 18.1 Discounted Cash Flow Forward Market Price (a) (10.12 ) 4.17 (0.31 ) Total $ 350.3 $ 307.8 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 Significant Unobservable Inputs March 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ 5.3 $ 2.2 Discounted Cash Flow Forward Market Price $ 9.95 $ 42.15 $ 21.81 FTRs 11.8 8.3 Discounted Cash Flow Forward Market Price — 3.44 0.42 Total $ 17.1 $ 10.5 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 Significant Unobservable Inputs March 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ 3.2 $ 1.3 Discounted Cash Flow Forward Market Price $ 9.95 $ 42.15 $ 21.81 FTRs 1.7 1.5 Discounted Cash Flow Forward Market Price (0.51 ) 2.77 0.12 Total $ 4.9 $ 2.8 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 Significant Unobservable Inputs March 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ — $ 120.9 Discounted Cash Flow Forward Market Price $ 12.57 $ 42.71 $ 26.31 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 Significant Unobservable Inputs March 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) FTRs $ 6.7 $ 0.4 Discounted Cash Flow Forward Market Price $ (7.07 ) $ 0.95 $ (2.38 ) 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 Significant Unobservable Inputs March 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input Low High Average (c) (in millions) Natural Gas Contracts $ — $ 5.1 Discounted Cash Flow Forward Market Price (b) $ 1.37 $ 2.51 $ 2.13 FTRs 2.7 0.1 Discounted Cash Flow Forward Market Price (a) (7.07 ) 0.95 (2.38 ) Total $ 2.7 $ 5.2 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. The following table provides the measurement uncertainty of fair value measurements to increases (decreases) in significant unobservable inputs related to Energy Contracts, Natural Gas Contracts and FTRs for the Registrants as of March 31, 2020 and December 31, 2019 : Uncertainty of Fair Value Measurements Significant Unobservable Input Position Change in Input Impact on Fair Value Measurement Forward Market Price Buy Increase (Decrease) Higher (Lower) Forward Market Price Sell Increase (Decrease) Lower (Higher)

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2020
Income Taxes	INCOME TAXES The disclosures in this note apply to all Registrants unless indicated otherwise. Federal Legislation In March 2020, the "Coronavirus Aid, Relief, and Economic Security Act" (CARES Act) was signed into law. The CARES Act includes several significant changes to the Internal Revenue Code that will have an impact on the Registrants. The CARES Act includes certain tax relief provisions applicable to the Registrants including a) the immediate refund of the corporate Alternative Minimum Tax credit, b) the ability to carryback net operating losses five years for tax years 2018 through 2020 and c) delayed payment of employer payroll taxes. As of March 31, 2020, AEP, OPCo and APCo have a $20 million , $9 million and $7 million AMT credit refund recorded, respectively, in anticipation of a refund from the U.S. Treasury. AEP was most recently a taxpayer in 2014 and management is currently evaluating the ability to recover cash taxes paid in 2014 under the 5-year net operating loss carryback provision. Effective Tax Rates (ETR) The Registrants’ interim ETR reflect the estimated annual ETR for 2020 and 2019 , adjusted for tax expense associated with certain discrete items. The interim ETR differ from the federal statutory tax rate of 21% primarily due to amortization of Excess ADIT, tax credits and other book/tax differences which are accounted for on a flow-through basis. The Registrants include the amortization of Excess ADIT not subject to normalization requirements in the annual estimated ETR when regulatory proceedings instruct the Registrants to provide the benefits of Tax Reform to customers over multiple interim periods. Certain regulatory proceedings instruct the Registrants to provide the benefits of Tax Reform to customers in a single period (e.g. by applying the Excess ADIT not subject to normalization requirements against an existing regulatory asset balance) and in these circumstances, the Registrants recognize the tax benefit discretely in the period recorded. The annual amount of Excess ADIT approved by the Registrant’s regulatory commissions may not impact the ETR ratably during each interim period due to the variability of pretax book income between interim periods and the application of an annual estimated ETR. The ETR for each of the Registrants are included in the following tables: Three Months Ended March 31, 2020 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo U.S. Federal Statutory Rate 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % Increase (decrease) due to: State Income Tax, net of Federal benefit 2.5 % 1.5 % 2.9 % 3.0 % 3.2 % 0.7 % 4.6 % 2.7 % Tax Reform Excess ADIT Reversal (9.4 )% (6.2 )% 0.4 % (13.0 )% (19.6 )% (10.2 )% (23.1 )% (94.7 )% Production and Investment Tax Credits (4.3 )% (0.4 )% — % — % (1.9 )% — % (1.3 )% (0.5 )% Flow Through 0.5 % 0.1 % 0.5 % 1.5 % 0.2 % 1.0 % 0.6 % (1.0 )% AFUDC Equity (1.4 )% (2.6 )% (2.6 )% (1.0 )% (1.1 )% (1.0 )% (0.7 )% (0.4 )% Parent Company Loss Benefit — % (0.2 )% (0.9 )% (3.3 )% (3.9 )% (0.1 )% (2.2 )% (2.4 )% Discrete Tax Adjustments — % — % — % — % 2.7 % — % — % — % Other (0.4 )% 0.3 % — % 0.1 % (0.2 )% — % 0.1 % 7.2 % Effective Income Tax Rate 8.5 % 13.5 % 21.3 % 8.3 % 0.4 % 11.4 % (1.0 )% (68.1 )% Three Months Ended March 31, 2019 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo U.S. Federal Statutory Rate 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % Increase (decrease) due to: State Income Tax, net of Federal benefit 2.1 % 1.5 % 2.9 % 3.4 % 2.0 % 0.9 % 4.6 % 0.2 % Tax Reform Excess ADIT Reversal (13.6 )% (7.6 )% 0.4 % (42.2 )% (17.4 )% (7.6 )% (21.9 )% (17.0 )% Production and Investment Tax Credits (2.2 )% (1.0 )% — % — % (2.0 )% — % (1.7 )% (0.8 )% Flow Through (0.2 )% 0.3 % 0.2 % (0.9 )% (2.4 )% 0.7 % 0.6 % (0.9 )% AFUDC Equity (1.4 )% (1.6 )% (2.5 )% (1.0 )% (1.9 )% (0.7 )% (0.4 )% (1.1 )% Parent Company Loss — % (2.3 )% (1.0 )% (2.4 )% (1.8 )% (1.1 )% (1.8 )% (0.5 )% Discrete Tax Adjustments 1.7 % — % — % 0.4 % — % — % — % — % Other (0.2 )% 0.1 % (0.1 )% (0.3 )% (0.3 )% 0.2 % 0.2 % 1.5 % Effective Income Tax Rate 7.2 % 10.4 % 20.9 % (22.0 )% (2.8 )% 13.4 % 0.6 % 2.4 % Federal and State Income Tax Audit Status AEP and subsidiaries are no longer subject to U.S. federal examination by the IRS for all years through 2015. During the third quarter of 2019, AEP and subsidiaries elected to amend the 2014 and 2015 federal returns and as such the IRS may examine only the amended items on the 2014 and 2015 federal returns.

Financing Activities

Financing Activities	3 Months Ended
	Mar. 31, 2020
Financing Activities	FINANCING ACTIVITIES The disclosures in this note apply to all Registrants, unless indicated otherwise. Long-term Debt Outstanding (Applies to AEP) The following table details long-term debt outstanding, net of issuance costs and premiums or discounts: Type of Debt March 31, 2020 December 31, 2019 (in millions) Senior Unsecured Notes $ 22,515.8 $ 21,180.7 Pollution Control Bonds 1,999.2 1,998.8 Notes Payable 209.4 234.3 Securitization Bonds 899.1 1,025.1 Spent Nuclear Fuel Obligation (a) 280.9 279.8 Junior Subordinated Notes (b) 788.6 787.8 Other Long-term Debt 1,199.7 1,219.0 Total Long-term Debt Outstanding 27,892.7 26,725.5 Long-term Debt Due Within One Year 2,109.7 1,598.7 Long-term Debt $ 25,783.0 $ 25,126.8 (a) Pursuant to the Nuclear Waste Policy Act of 1982, I&M, a nuclear licensee, has an obligation to the United States Department of Energy for SNF disposal. The obligation includes a one-time fee for nuclear fuel consumed prior to April 7, 1983. Trust fund assets related to this obligation were $324 million and $323 million as of March 31, 2020 and December 31, 2019 , respectively, and are included in Spent Nuclear Fuel and Decommissioning Trusts on the balance sheets. (b) See “Equity Units” section below for additional information. Long-term Debt Activity Long-term debt and other securities issued, retired and principal payments made during the first three months of 2020 are shown in the following tables: Principal Interest Company Type of Debt Amount (a) Rate Due Date Issuances: (in millions) (%) AEP Senior Unsecured Notes $ 400.0 2.30 2030 AEP Senior Unsecured Notes 400.0 3.25 2050 OPCo Senior Unsecured Notes 350.0 2.60 2030 Non-Registrant: KPCo Other Long-term Debt 125.0 Variable 2022 Transource Energy Other Long-term Debt 5.0 Variable 2023 Transource Energy Senior Unsecured Notes 150.0 2.75 2050 Total Issuances $ 1,430.0 (a) Amounts indicated on the statements of cash flows are net of issuance costs and premium or discount and will not tie to the issuance amounts. Principal Interest Company Type of Debt Amount Paid Rate Due Date Retirements and Principal Payments: (in millions) (%) AEP Texas Securitization Bonds $ 111.0 5.31 2020 AEP Texas Securitization Bonds 3.3 2.06 2025 APCo Securitization Bonds 12.2 2.01 2023 I&M Notes Payable 0.7 Variable 2020 I&M Notes Payable 1.5 Variable 2021 I&M Notes Payable 5.1 Variable 2022 I&M Notes Payable 3.8 Variable 2022 I&M Notes Payable 6.2 Variable 2023 I&M Notes Payable 6.0 Variable 2024 I&M Other Long-term Debt 0.4 6.00 2025 PSO Other Long-term Debt 0.1 3.00 2027 SWEPCo Notes Payable 1.6 4.58 2032 Non-Registrant: Transource Energy Other Long-term Debt 148.6 Variable 2023 Total Retirements and Principal Payments $ 300.5 Long-term Debt Subsequent Events In April 2020, AEPTCo issued $525 million of 3.65% Senior Unsecured Notes due in 2050 . In April and May 2020, I&M retired $8 million and $1 million , respectively, of Notes Payable related to DCC Fuel. In April 2020, Transource Energy issued $1 million of variable rate Other Long-term Debt due in 2023 . Equity Units (Applies to AEP) In March 2019, AEP issued 16.1 million Equity Units initially in the form of corporate units, at a stated amount of $50 per unit, for a total stated amount of $805 million . Net proceeds from the issuance were approximately $785 million . The proceeds were used to support AEP’s overall capital expenditure plans including the acquisition of Sempra Renewables LLC. Each corporate unit represents a 1/20 undivided beneficial ownership interest in $1,000 principal amount of AEP’s 3.40% Junior Subordinated Notes (notes) due in 2024 and a forward equity purchase contract which settles after three years in 2022 . The notes are expected to be remarketed in 2022, at which time the interest rate will reset at the then current market rate. Investors may choose to remarket their notes to receive the remarketing proceeds and use those funds to settle the forward equity purchase contract, or accept the remarketed debt and use other funds for the equity purchase. If the remarketing is unsuccessful, investors have the right to put their notes to AEP at a price equal to the principal. The Equity Units carry an annual distribution rate of 6.125% , which is comprised of a quarterly coupon rate of interest of 3.40% and a quarterly forward equity purchase contract payment of 2.725% . Each forward equity purchase contract obligates the holder to purchase, and AEP to sell, for $50 a number of shares in common stock in accordance with the conversion ratios set forth below (subject to an anti-dilution adjustment): • If the AEP common stock market price is equal to or greater than $99.58 : 0.5021 shares per contract. • If the AEP common stock market price is less than $99.58 but greater than $82.98 : a number of shares per contract equal to $50 divided by the applicable market price. The holder receives a variable number of shares at $50. • If the AEP common stock market price is less than or equal to $82.98 : 0.6026 shares per contract. A holder’s ownership interest in the notes is pledged to AEP to secure the holder’s obligation under the related forward equity purchase contract. If a holder of the forward equity purchase contract chooses at any time to no longer be a holder of the notes, such holder’s obligation under the forward equity purchase contract must be secured by a U.S. Treasury security which must be equal to the aggregate principal amount of the notes. At the time of issuance, the $805 million of notes were recorded within Long-term Debt on the balance sheets. The present value of the purchase contract payments of $62 million were recorded in Deferred Credits and Other Noncurrent Liabilities with a current portion in Other Current Liabilities at the time of issuance, representing the obligation to make forward equity contract payments, with an offsetting reduction to Paid-in Capital. The difference between the face value and present value of the purchase contract payments will be accreted to Interest Expense on the statements of income over the three year period ending in 2022. The liability recorded for the contract payments is considered non-cash and excluded from the statements of cash flows. Until settlement of the forward equity purchase contract, earnings per share dilution resulting from the equity unit issuance will be determined under the treasury stock method. The maximum amount of shares AEP will be required to issue to settle the purchase contract is 9,701,860 shares (subject to an anti-dilution adjustment). Debt Covenants (Applies to AEP and AEPTCo) Covenants in AEPTCo’s note purchase agreements and indenture limit the amount of contractually-defined priority debt (which includes a further sub-limit of $50 million of secured debt) to 10% of consolidated tangible net assets. AEPTCo’s contractually-defined priority debt was 3.3% of consolidated tangible net assets as of March 31, 2020 . The method for calculating the consolidated tangible net assets is contractually-defined in the note purchase agreements. 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 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 Federal Power Act restriction does not limit the ability of the AEP subsidiaries to pay dividends out of retained earnings. 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. 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 March 31, 2020 and December 31, 2019 are included in Advances to Affiliates and Advances from Affiliates, respectively, on the Registrant Subsidiaries’ balance sheets. The Utility Money Pool participants’ activity and corresponding authorized borrowing limits for the three months ended March 31, 2020 are described in the following table: Maximum Average Net 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 March 31, 2020 Limit (in millions) AEP Texas $ 63.9 $ 199.7 $ 39.0 $ 90.3 $ (63.9 ) $ 500.0 AEPTCo 358.4 69.8 257.6 32.6 (261.0 ) 820.0 (a) APCo 373.5 22.2 303.1 22.0 (333.5 ) 500.0 I&M 147.5 13.3 108.4 13.3 (90.4 ) 500.0 OPCo 353.9 32.8 191.5 25.2 (29.4 ) 500.0 PSO 70.9 57.1 25.3 28.4 (70.9 ) 300.0 SWEPCo 152.8 — 105.5 — (148.1 ) 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 table 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 March 31, 2020 and December 31, 2019 are included in Advances to Affiliates on the subsidiaries’ balance sheets. The Nonutility Money Pool participants’ activity for the three months ended March 31, 2020 is described in the following table: Maximum Loans Average Loans Loans to the Nonutility to the Nonutility to the Nonutility Money Pool as of Company Money Pool Money Pool March 31, 2020 (in millions) AEP Texas $ 7.5 $ 7.2 $ 7.1 SWEPCo 2.1 2.1 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 March 31, 2020 and December 31, 2019 are included in Advances to Affiliates and Advances from Affiliates, respectively, on AEPTCo’s balance sheets. AEPTCo’s direct borrowing and lending activity with AEP and corresponding authorized borrowing limit for the three months ended March 31, 2020 are described in the following table: 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 March 31, 2020 March 31, 2020 Borrowing Limit (in millions) $ 1.4 $ 190.3 $ 1.4 $ 125.1 $ 1.3 $ 93.3 $ 50.0 (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: Three Months Ended March 31, 2020 2019 Maximum Interest Rate 2.24 % 3.02 % Minimum Interest Rate 1.76 % 2.73 % The average interest rates for funds borrowed from and loaned to the Utility Money Pool are summarized for all Registrant Subsidiaries in the following table: Average Interest Rate for Funds Average Interest Rate for Funds Borrowed from the Utility Money Pool Loaned to the Utility Money Pool for Three Months Ended March 31, for Three Months Ended March 31, Company 2020 2019 2020 2019 AEP Texas 2.05 % 2.86 % 1.97 % — % AEPTCo 1.95 % 2.83 % 1.91 % 2.90 % APCo 1.95 % 2.92 % 1.94 % 2.79 % I&M 1.95 % 2.80 % 1.94 % 2.87 % OPCo 1.90 % 2.85 % 2.06 % — % PSO 2.00 % 2.89 % 1.95 % — % SWEPCo 1.95 % 2.81 % — % 2.97 % Maximum, minimum and average interest rates for funds loaned to the Nonutility Money Pool are summarized in the following table: Three Months Ended March 31, 2020 Three Months Ended March 31, 2019 Maximum Minimum Average Maximum Minimum 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 Loaned to Loaned to Loaned to Loaned to Loaned to Loaned to the Nonutility the Nonutility the Nonutility the Nonutility the Nonutility the Nonutility Company Money Pool Money Pool Money Pool Money Pool Money Pool Money Pool AEP Texas 2.24 % 1.76 % 1.94 % 3.02 % 2.73 % 2.87 % SWEPCo 2.24 % 1.76 % 1.94 % 3.02 % 2.73 % 2.87 % 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 Three Months for Funds for Funds for Funds for Funds for Funds for Funds Ended Borrowed Borrowed Loaned Loaned Borrowed Loaned March 31, from AEP from AEP to AEP to AEP from AEP to AEP 2020 2.24 % 1.76 % 2.24 % 1.76 % 1.94 % 1.94 % 2019 3.02 % 2.73 % 3.02 % 2.73 % 2.87 % 2.86 % Short-term Debt (Applies to AEP and SWEPCo) Outstanding short-term debt was as follows: March 31, 2020 December 31, 2019 Outstanding Interest Outstanding Interest Company Type of Debt Amount Rate (a) Amount Rate (a) (dollars in millions) AEP Securitized Debt for Receivables (b) $ 724.0 1.75 % $ 710.0 2.42 % AEP Commercial Paper 2,709.6 2.24 % 2,110.0 2.10 % AEP 364-Day Term Loan 1,000.0 1.53 % — — % SWEPCo Notes Payable 30.5 2.98 % 18.3 3.29 % Total Short-term Debt $ 4,464.1 $ 2,838.3 (a) Weighted-average rate. (b) Amount of securitized debt for receivables as accounted for under the “Transfers and Servicing” accounting guidance. Credit Facilities For a discussion of credit facilities, see “Letters of Credit” section of Note 5 . Securitized Accounts Receivables – AEP Credit (Applies to AEP) AEP Credit has a receivables securitization agreement that provides a commitment of $750 million from bank conduits to purchase receivables and expires in July 2021. Under the securitization agreement, AEP Credit receives financing from the bank conduits for the interest in the receivables AEP Credit acquires from affiliated utility subsidiaries. These securitized transactions allow AEP Credit to repay its outstanding debt obligations, continue to purchase the operating companies’ receivables and accelerate AEP Credit’s cash collections. Accounts receivable information for AEP Credit was as follows: Three Months Ended 2020 2019 (dollars in millions) Effective Interest Rates on Securitization of Accounts Receivable 1.75 % 2.71 % Net Uncollectible Accounts Receivable Written-Off $ 4.2 $ 6.4 March 31, 2020 December 31, 2019 (in millions) Accounts Receivable Retained Interest and Pledged as Collateral Less Uncollectible Accounts $ 850.7 $ 841.8 Short-term – Securitized Debt of Receivables 724.0 710.0 Delinquent Securitized Accounts Receivable 43.4 39.6 Bad Debt Reserves Related to Securitization 34.5 32.1 Unbilled Receivables Related to Securitization 219.8 266.8 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 agreements were: Company March 31, 2020 December 31, 2019 (in millions) APCo $ 121.8 $ 120.9 I&M 155.2 141.8 OPCo 338.3 330.3 PSO 93.3 101.1 SWEPCo 121.2 125.2 The fees paid to AEP Credit for customer accounts receivable sold were: Three Months Ended March 31, Company 2020 2019 (in millions) APCo $ 1.7 $ 2.2 I&M 2.8 2.8 OPCo 4.8 7.8 PSO 1.3 2.1 SWEPCo 2.1 2.6 The proceeds on the sale of receivables to AEP Credit were: Three Months Ended March 31, Company 2020 2019 (in millions) APCo $ 352.6 $ 374.4 I&M 471.4 478.6 OPCo 570.3 636.8 PSO 294.9 324.5 SWEPCo 365.6 371.9

Revenue from Contracts with Cus

Revenue from Contracts with Customers	3 Months Ended
	Mar. 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 tables below represent AEP’s reportable segment revenues from contracts with customers, net of respective provisions for refund, by type of revenue: Three Months Ended March 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 $ 915.1 $ 521.3 $ — $ — $ — $ — $ 1,436.4 Commercial Revenues 489.4 276.9 — — — — 766.3 Industrial Revenues 518.2 97.8 — — — (0.2 ) 615.8 Other Retail Revenues 39.9 11.8 — — — — 51.7 Total Retail Revenues 1,962.6 907.8 — — — (0.2 ) 2,870.2 Wholesale and Competitive Retail Revenues: Generation Revenues 140.4 — — 44.1 — — 184.5 Transmission Revenues (a) 79.9 114.1 309.8 — — (263.0 ) 240.8 Renewable Generation Revenues (c) — — — 17.2 — (0.6 ) 16.6 Retail, Trading and Marketing Revenues (b) — — — 358.7 (6.0 ) (29.4 ) 323.3 Total Wholesale and Competitive Retail Revenues 220.3 114.1 309.8 420.0 (6.0 ) (293.0 ) 765.2 Other Revenues from Contracts with Customers (c) 43.6 36.4 3.7 0.3 28.1 (40.6 ) 71.5 Total Revenues from Contracts with Customers 2,226.5 1,058.3 313.5 420.3 22.1 (333.8 ) 3,706.9 Other Revenues: Alternative Revenues (c) 0.2 19.3 (3.3 ) — — 4.5 20.7 Other Revenues (c) — 29.3 — 18.3 (2.2 ) (25.5 ) 19.9 Total Other Revenues 0.2 48.6 (3.3 ) 18.3 (2.2 ) (21.0 ) 40.6 Total Revenues $ 2,226.7 $ 1,106.9 $ 310.2 $ 438.6 $ 19.9 $ (354.8 ) $ 3,747.5 (a) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $239 million . The remaining affiliated amounts were immaterial. (b) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $35 million . The remaining affiliated amounts were immaterial. (c) Amounts include affiliated and nonaffiliated revenues. Three Months Ended March 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 $ 982.4 $ 586.1 $ — $ — $ — $ — $ 1,568.5 Commercial Revenues 511.2 310.9 — — — — 822.1 Industrial Revenues 532.1 123.9 — — — 1.8 657.8 Other Retail Revenues 43.3 11.1 — — — — 54.4 Total Retail Revenues 2,069.0 1,032.0 — — — 1.8 3,102.8 Wholesale and Competitive Retail Revenues: Generation Revenues 224.7 — — 108.8 — (38.8 ) 294.7 Transmission Revenues (a) 73.5 99.6 255.1 — — (219.4 ) 208.8 Renewable Generation Revenues (c) — — — 7.8 — — 7.8 Retail, Trading and Marketing Revenues (b) — — — 353.7 — — 353.7 Total Wholesale and Competitive Retail Revenues 298.2 99.6 255.1 470.3 — (258.2 ) 865.0 Other Revenues from Contracts with Customers (c) 39.5 46.0 3.1 2.3 23.3 (36.1 ) 78.1 Total Revenues from Contracts with Customers 2,406.7 1,177.6 258.2 472.6 23.3 (292.5 ) 4,045.9 Other Revenues: Alternative Revenues (c) (3.4 ) 5.0 (1.8 ) — — — (0.2 ) Other Revenues (c) — 39.4 — 9.2 2.2 (39.7 ) 11.1 Total Other Revenues (3.4 ) 44.4 (1.8 ) 9.2 2.2 (39.7 ) 10.9 Total Revenues $ 2,403.3 $ 1,222.0 $ 256.4 $ 481.8 $ 25.5 $ (332.2 ) $ 4,056.8 (a) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $198 million . The remaining affiliated amounts were immaterial. (b) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $37 million . The remaining affiliated amounts were immaterial. (c) Amounts include affiliated and nonaffiliated revenues. Three Months Ended March 31, 2020 AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Retail Revenues: Residential Revenues $ 132.9 $ — $ 357.5 $ 201.3 $ 388.4 $ 128.5 $ 131.6 Commercial Revenues 112.8 — 132.3 122.2 164.0 76.1 105.6 Industrial Revenues 35.2 — 141.1 137.8 62.7 61.3 79.8 Other Retail Revenues 8.4 — 17.9 1.8 3.4 16.6 2.0 Total Retail Revenues 289.3 — 648.8 463.1 618.5 282.5 319.0 Wholesale Revenues: Generation Revenues (a) — — 54.1 78.4 — 1.9 34.1 Transmission Revenues (b) 96.9 298.2 30.4 7.4 17.1 7.8 25.4 Total Wholesale Revenues 96.9 298.2 84.5 85.8 17.1 9.7 59.5 Other Revenues from Contracts with Customers (c) 7.9 3.4 17.2 21.0 28.6 4.7 5.8 Total Revenues from Contracts with Customers 394.1 301.6 750.5 569.9 664.2 296.9 384.3 Other Revenues: Alternative Revenues (d) (0.7 ) (6.0 ) (1.1 ) 0.4 20.0 0.4 1.6 Other Revenues (d) 30.2 — — — 6.1 — — Total Other Revenues 29.5 (6.0 ) (1.1 ) 0.4 26.1 0.4 1.6 Total Revenues $ 423.6 $ 295.6 $ 749.4 $ 570.3 $ 690.3 $ 297.3 $ 385.9 (a) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $33 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 $235 million . The remaining affiliated amounts were immaterial. (c) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $16 million primarily relating to the barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial. (d) Amounts include affiliated and nonaffiliated revenues. Three Months Ended March 31, 2019 AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Retail Revenues: Residential Revenues $ 120.9 $ — $ 372.5 $ 218.4 $ 471.6 $ 140.0 $ 140.1 Commercial Revenues 97.9 — 142.2 121.3 210.5 80.8 113.7 Industrial Revenues 33.0 — 147.5 138.4 89.7 71.0 81.2 Other Retail Revenues 7.3 — 19.6 1.8 3.4 18.0 2.2 Total Retail Revenues 259.1 — 681.8 479.9 775.2 309.8 337.2 Wholesale Revenues: Generation Revenues (a) — — 67.5 111.9 — 8.6 57.2 Transmission Revenues (b) 85.8 242.1 25.7 6.3 13.9 9.8 24.2 Total Wholesale Revenues 85.8 242.1 93.2 118.2 13.9 18.4 81.4 Other Revenues from Contracts with Customers (c) 6.9 3.1 13.4 21.0 39.0 5.8 7.8 Total Revenues from Contracts with Customers 351.8 245.2 788.4 619.1 828.1 334.0 426.4 Other Revenues: Alternative Revenues (d) (0.9 ) (1.7 ) 4.4 (4.8 ) 3.6 (1.2 ) (5.3 ) Other Revenues (d) 39.8 — — — 5.1 — — Total Other Revenues 38.9 (1.7 ) 4.4 (4.8 ) 8.7 (1.2 ) (5.3 ) Total Revenues $ 390.7 $ 243.5 $ 792.8 $ 614.3 $ 836.8 $ 332.8 $ 421.1 (a) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $35 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 $195 million . The remaining affiliated amounts were immaterial. (c) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $15 million primarily relating to the barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial. (d) Amounts include affiliated and nonaffiliated revenues. Fixed Performance Obligations The following table represents the Registrants’ remaining fixed performance obligations satisfied over time as of March 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 2020 2021-2022 2023-2024 After 2024 Total (in millions) AEP $ 732.4 $ 171.1 $ 160.6 $ 223.4 $ 1,287.5 AEP Texas 290.3 — — — 290.3 AEPTCo 821.5 — — — 821.5 APCo 118.6 32.3 24.4 11.6 186.9 I&M 22.2 8.8 8.8 4.4 44.2 OPCo 43.2 — — — 43.2 PSO 10.8 — — — 10.8 SWEPCo 29.6 — — — 29.6 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 material contract assets as of March 31, 2020 and December 31, 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 material contract liabilities as of March 31, 2020 and December 31, 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 March 31, 2020 and December 31, 2019 . See “Securitized Accounts Receivable - AEP Credit” section of Note 12 for additional information related to AEP Credit’s securitized accounts receivable. 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: Company March 31, 2020 December 31, 2019 (in millions) AEPTCo $ 80.6 $ 65.9 APCo 56.3 47.3 I&M 37.4 37.1 OPCo 39.3 33.9 PSO 6.2 9.7 SWEPCo 11.0 17.6

Significant Accounting Matters

Significant Accounting Matters (Policies)	3 Months Ended
	Mar. 31, 2020
Basis of Accounting	General The unaudited condensed financial statements and footnotes were prepared in accordance with GAAP for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X of the SEC. Accordingly, they do not include all of the information and footnotes required by GAAP for complete annual financial statements. In the opinion of management, the unaudited condensed interim financial statements reflect all normal and recurring accruals and adjustments necessary for a fair statement of the net income, financial position and cash flows for the interim periods for each Registrant. Net income for the three months ended March 31, 2020 is not necessarily indicative of results that may be expected for the year ending December 31, 2020 . The condensed financial statements are unaudited and should be read in conjunction with the audited 2019 financial statements and notes thereto, which are included in the Registrants’ Annual Reports on Form 10-K as filed with the SEC on February 20, 2020 .
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 awards.

Derivatives and Hedging (Polici

Derivatives and Hedging (Policies)	3 Months Ended
	Mar. 31, 2020
Derivatives and Hedging	Credit Risk Management mitigates credit risk in wholesale marketing and trading activities by assessing the creditworthiness of potential counterparties before entering into transactions with them and continuing to evaluate their creditworthiness on an ongoing basis. Management uses credit agency ratings and current market-based qualitative and quantitative data as well as financial statements to assess the financial health of counterparties on an ongoing basis. Master agreements are typically used to facilitate the netting of cash flows associated with a single counterparty and may include collateral requirements. Collateral requirements in the form of cash, letters of credit and parental/affiliate guarantees may be obtained as security from counterparties in order to mitigate credit risk. Some master agreements include margining, which requires a counterparty to post cash or letters of credit in the event exposure exceeds the established threshold. The threshold represents an unsecured credit limit which may be supported by a parental/affiliate guaranty, as determined in accordance with AEP’s credit policy. In addition, master agreements allow for termination and liquidation of all positions in the event of a default including a failure or inability to post collateral when required. Collateral Triggering Events Credit Downgrade Triggers (Applies to AEP, APCo, I&M, PSO and SWEPCo) Fair Value Hedging Strategies (Applies to AEP) Parent enters into interest rate derivative transactions as part of an overall strategy to manage the mix of fixed-rate and floating-rate debt. Certain interest rate derivative transactions effectively modify exposure to interest rate risk by converting a portion of fixed-rate debt to a floating-rate. Provided specific criteria are met, these interest rate derivatives may be designated as fair value hedges. Cash Flow Hedging Strategies The Registrants utilize cash flow hedges on certain derivative transactions for the purchase and sale of power (“Commodity”) in order to manage the variable price risk related to forecasted purchases and sales. Management monitors the potential impacts of commodity price changes and, where appropriate, enters into derivative transactions to protect profit margins for a portion of future electricity sales and purchases. The Registrants do not hedge all commodity price risk. The Registrants utilize a variety of interest rate derivative transactions in order to manage interest rate risk exposure. The Registrants also utilize interest rate derivative contracts to manage interest rate exposure related to future borrowings of fixed-rate debt. The Registrants do not hedge all interest rate exposure. ACCOUNTING FOR DERIVATIVE INSTRUMENTS AND THE IMPACT ON THE FINANCIAL STATEMENTS The accounting guidance for “Derivatives and Hedging” requires recognition of all qualifying derivative instruments as either assets or liabilities on the balance sheets at fair value. The fair values of derivative instruments accounted for using MTM accounting or hedge accounting are based on exchange prices and broker quotes. If a quoted market price is not available, the estimate of fair value is based on the best information available including valuation models that estimate future energy prices based on existing market and broker quotes, supply and demand market data and assumptions. In order to determine the relevant fair values of the derivative instruments, the Registrants apply valuation adjustments for discounting, liquidity and credit quality. Credit risk is the risk that a counterparty will fail to perform on the contract or fail to pay amounts due. Liquidity risk represents the risk that imperfections in the market will cause the price to vary from estimated fair value based upon prevailing market supply and demand conditions. Since energy markets are imperfect and volatile, there are inherent risks related to the underlying assumptions in models used to fair value risk management contracts. Unforeseen events may cause reasonable price curves to differ from actual price curves throughout a contract’s term and at the time a contract settles. Consequently, there could be significant adverse or favorable effects on future net income and cash flows if market prices are not consistent with management’s estimates of current market consensus for forward prices in the current period. This is particularly true for longer term contracts. Cash flows may vary based on market conditions, margin requirements and the timing of settlement of risk management contracts. 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. 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 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. 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.

Fair Value Measurements (Polici

Fair Value Measurements (Policies)	3 Months Ended
	Mar. 31, 2020
Valuation Techniques	Fair Value Hierarchy and Valuation Techniques 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 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 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.
Fair Values of Long-term Debt	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.
Trust Assets for Decommissioning and Spent Nuclear Fuel Disposal	Fair Value Measurements of Trust Assets for Decommissioning and SNF Disposal (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 external investment managers who must comply with the guidelines and rules of the applicable regulatory authorities. The trust assets are invested to optimize the net of tax earnings of the trust giving consideration to liquidity, risk, diversification and other prudent investment objectives. I&M records securities held in these trust funds in Spent Nuclear Fuel and Decommissioning Trusts on its balance sheets. I&M records these securities at fair value. I&M classifies securities in the trust funds as available-for-sale due to their long-term purpose. Available-for-sale classification only applies to investment in debt securities in accordance with ASU 2016-01. Additionally, ASU 2016-01 requires changes in fair value of equity securities to be recognized in earnings. However, due to the regulatory treatment described below, this is not applicable for I&M’s trust fund securities. Other-than-temporary impairments for investments in debt securities are considered realized losses as a result of securities being managed by an external investment management firm. The external investment management firm makes specific investment decisions regarding the debt and equity investments held in these trusts and generally intends to sell debt securities in an unrealized loss position as part of a tax optimization strategy. Impairments reduce the cost basis of the securities which will affect any future unrealized gain or realized gain or loss due to the adjusted cost of investment. I&M records unrealized gains, unrealized losses and other-than-temporary impairments from securities in these trust funds as adjustments to the regulatory liability account for the nuclear decommissioning trust funds and to regulatory assets or liabilities for the SNF disposal trust funds in accordance with their treatment in rates. Consequently, changes in fair value of trust assets do not affect earnings or AOCI.
Fair Value Assets and Liabilities Measured on Recurring Basis	Fair Value Measurements of Financial Assets and Liabilities 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.

Income Taxes Amortization of Ex

Income Taxes Amortization of Excess ADIT not Subject to Normalization Requirements Policy (Policies)	3 Months Ended
	Mar. 31, 2020
Amortization of Excess ADIT Not Subject to Normalization Requirements [Line Items]
Amortization of Excess ADIT Not Subject to Normalization Requirements Policy [Table Text Block]	The Registrants include the amortization of Excess ADIT not subject to normalization requirements in the annual estimated ETR when regulatory proceedings instruct the Registrants to provide the benefits of Tax Reform to customers over multiple interim periods. Certain regulatory proceedings instruct the Registrants to provide the benefits of Tax Reform to customers in a single period (e.g. by applying the Excess ADIT not subject to normalization requirements against an existing regulatory asset balance) and in these circumstances, the Registrants recognize the tax benefit discretely in the period recorded. The annual amount of Excess ADIT approved by the Registrant’s regulatory commissions may not impact the ETR ratably during each interim period due to the variability of pretax book income between interim periods and the application of an annual estimated ETR.

Significant Accounting Matter_2

Significant Accounting Matters (Tables)	3 Months Ended
	Mar. 31, 2020
Basic and Diluted EPS Calculations	Three Months Ended March 31, 2020 2019 (in millions, except per share data) $/share $/share Earnings Attributable to AEP Common Shareholders $ 495.2 $ 572.8 Weighted Average Number of Basic Shares Outstanding 494.6 $ 1.00 493.3 $ 1.16 Weighted Average Dilutive Effect of Stock-Based Awards 2.0 — 1.2 — Weighted Average Number of Diluted Shares Outstanding 496.6 $ 1.00 494.5 $ 1.16
Supplementary Information	March 31, 2020 AEP AEP Texas APCo (in millions) Cash and Cash Equivalents $ 1,554.6 $ 0.1 $ 2.8 Restricted Cash 116.2 100.1 15.7 Total Cash, Cash Equivalents and Restricted Cash $ 1,670.8 $ 100.2 $ 18.5 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

Comprehensive Income (Tables)

Comprehensive Income (Tables)	3 Months Ended
	Mar. 31, 2020
Changes in Accumulated Other Comprehensive Income (Loss) by Component	AEP Cash Flow Hedges Pension Three Months Ended March 31, 2020 Commodity Interest Rate and OPEB Total (in millions) Balance in AOCI as of December 31, 2019 $ (103.5 ) $ (11.5 ) $ (32.7 ) $ (147.7 ) Change in Fair Value Recognized in AOCI (65.3 ) (42.7 ) (a) — (108.0 ) Amount of (Gain) Loss Reclassified from AOCI Generation & Marketing Revenues (a) (0.1 ) — — (0.1 ) Purchased Electricity for Resale (b) 51.1 — — 51.1 Interest Expense (b) — 0.9 — 0.9 Amortization of Prior Service Cost (Credit) — — (4.9 ) (4.9 ) Amortization of Actuarial (Gains) Losses — — 2.6 2.6 Reclassifications from AOCI, before Income Tax (Expense) Benefit 51.0 0.9 (2.3 ) 49.6 Income Tax (Expense) Benefit 10.7 0.2 (0.5 ) 10.4 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 40.3 0.7 (1.8 ) 39.2 Net Current Period Other Comprehensive Income (Loss) (25.0 ) (42.0 ) (1.8 ) (68.8 ) Balance in AOCI as of March 31, 2020 $ (128.5 ) $ (53.5 ) $ (34.5 ) $ (216.5 ) Cash Flow Hedges Pension Three Months Ended March 31, 2019 Commodity Interest Rate and OPEB Total (in millions) Balance in AOCI as of December 31, 2018 $ (23.0 ) $ (12.6 ) $ (84.8 ) $ (120.4 ) Change in Fair Value Recognized in AOCI (38.8 ) — — (38.8 ) Amount of (Gain) Loss Reclassified from AOCI Purchased Electricity for Resale (b) 12.3 — — 12.3 Interest Expense (b) — 0.2 — 0.2 Amortization of Prior Service Cost (Credit) — — (4.8 ) (4.8 ) Amortization of Actuarial (Gains) Losses — — 3.0 3.0 Reclassifications from AOCI, before Income Tax (Expense) Benefit 12.3 0.2 (1.8 ) 10.7 Income Tax (Expense) Benefit 2.6 — (0.4 ) 2.2 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 9.7 0.2 (1.4 ) 8.5 Net Current Period Other Comprehensive Income (Loss) (29.1 ) 0.2 (1.4 ) (30.3 ) Balance in AOCI as of March 31, 2019 $ (52.1 ) $ (12.4 ) $ (86.2 ) $ (150.7 ) AEP Texas Cash Flow Hedge – Pension Three Months Ended March 31, 2020 Interest Rate and OPEB Total (in millions) Balance in AOCI as of December 31, 2019 $ (3.4 ) $ (9.4 ) $ (12.8 ) Change in Fair Value Recognized in AOCI — — — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 0.4 — 0.4 Reclassifications from AOCI, before Income Tax (Expense) Benefit 0.4 — 0.4 Income Tax (Expense) Benefit 0.1 — 0.1 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 0.3 — 0.3 Net Current Period Other Comprehensive Income (Loss) 0.3 — 0.3 Balance in AOCI as of March 31, 2020 $ (3.1 ) $ (9.4 ) $ (12.5 ) Cash Flow Hedge – Pension Three Months Ended March 31, 2019 Interest Rate and OPEB Total (in millions) Balance in AOCI as of December 31, 2018 $ (4.4 ) $ (10.7 ) $ (15.1 ) Change in Fair Value Recognized in AOCI — — — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 0.4 — 0.4 Reclassifications from AOCI, before Income Tax (Expense) Benefit 0.4 — 0.4 Income Tax (Expense) Benefit 0.1 — 0.1 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 0.3 — 0.3 Net Current Period Other Comprehensive Income (Loss) 0.3 — 0.3 Balance in AOCI as of March 31, 2019 $ (4.1 ) $ (10.7 ) $ (14.8 ) APCo Cash Flow Hedge – Pension Three Months Ended March 31, 2020 Interest Rate and OPEB Total (in millions) Balance in AOCI as of December 31, 2019 $ 0.9 $ 4.1 $ 5.0 Change in Fair Value Recognized in AOCI (3.9 ) — (3.9 ) Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (0.4 ) — (0.4 ) Amortization of Prior Service Cost (Credit) — (1.3 ) (1.3 ) Amortization of Actuarial (Gains) Losses — 0.1 0.1 Reclassifications from AOCI, before Income Tax (Expense) Benefit (0.4 ) (1.2 ) (1.6 ) Income Tax (Expense) Benefit (0.1 ) (0.3 ) (0.4 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (0.3 ) (0.9 ) (1.2 ) Net Current Period Other Comprehensive Income (Loss) (4.2 ) (0.9 ) (5.1 ) Balance in AOCI as of March 31, 2020 $ (3.3 ) $ 3.2 $ (0.1 ) Cash Flow Hedge – Pension Three Months Ended March 31, 2019 Interest Rate and OPEB Total (in millions) Balance in AOCI as of December 31, 2018 $ 1.8 $ (6.8 ) $ (5.0 ) Change in Fair Value Recognized in AOCI — — — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) (0.3 ) — (0.3 ) Amortization of Prior Service Cost (Credit) — (1.3 ) (1.3 ) Amortization of Actuarial (Gains) Losses — 0.5 0.5 Reclassifications from AOCI, before Income Tax (Expense) Benefit (0.3 ) (0.8 ) (1.1 ) Income Tax (Expense) Benefit (0.1 ) (0.2 ) (0.3 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (0.2 ) (0.6 ) (0.8 ) Net Current Period Other Comprehensive Income (Loss) (0.2 ) (0.6 ) (0.8 ) Balance in AOCI as of March 31, 2019 $ 1.6 $ (7.4 ) $ (5.8 ) I&M Cash Flow Hedge – Pension Three Months Ended March 31, 2020 Interest Rate and OPEB Total (in millions) Balance in AOCI as of December 31, 2019 $ (9.9 ) $ (1.7 ) $ (11.6 ) Change in Fair Value Recognized in AOCI — — — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 0.5 — 0.5 Amortization of Prior Service Cost (Credit) — (0.2 ) (0.2 ) Amortization of Actuarial (Gains) Losses — 0.2 0.2 Reclassifications from AOCI, before Income Tax (Expense) Benefit 0.5 — 0.5 Income Tax (Expense) Benefit 0.1 — 0.1 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 0.4 — 0.4 Net Current Period Other Comprehensive Income (Loss) 0.4 — 0.4 Balance in AOCI as of March 31, 2020 $ (9.5 ) $ (1.7 ) $ (11.2 ) Cash Flow Hedge – Pension Three Months Ended March 31, 2019 Interest Rate and OPEB Total (in millions) Balance in AOCI as of December 31, 2018 $ (11.5 ) $ (2.3 ) $ (13.8 ) Change in Fair Value Recognized in AOCI — — — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 0.5 — 0.5 Amortization of Prior Service Cost (Credit) — (0.2 ) (0.2 ) Amortization of Actuarial (Gains) Losses — 0.2 0.2 Reclassifications from AOCI, before Income Tax (Expense) Benefit 0.5 — 0.5 Income Tax (Expense) Benefit 0.1 — 0.1 Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 0.4 — 0.4 Net Current Period Other Comprehensive Income (Loss) 0.4 — 0.4 Balance in AOCI as of March 31, 2019 $ (11.1 ) $ (2.3 ) $ (13.4 ) OPCo Cash Flow Hedge – Three Months Ended March 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 March 31, 2020 $ — Cash Flow Hedge – Three Months Ended March 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) (0.4 ) Reclassifications from AOCI, before Income Tax (Expense) Benefit (0.4 ) Income Tax (Expense) Benefit (0.1 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (0.3 ) Net Current Period Other Comprehensive Income (Loss) (0.3 ) Balance in AOCI as of March 31, 2019 $ 0.7 PSO Cash Flow Hedge – Three Months Ended March 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) (0.3 ) Reclassifications from AOCI, before Income Tax (Expense) Benefit (0.3 ) Income Tax (Expense) Benefit (0.1 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (0.2 ) Net Current Period Other Comprehensive Income (Loss) (0.2 ) Balance in AOCI as of March 31, 2020 $ 0.9 Cash Flow Hedge – Three Months Ended March 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) (0.3 ) Reclassifications from AOCI, before Income Tax (Expense) Benefit (0.3 ) Income Tax (Expense) Benefit (0.1 ) Reclassifications from AOCI, Net of Income Tax (Expense) Benefit (0.2 ) Net Current Period Other Comprehensive Income (Loss) (0.2 ) Balance in AOCI as of March 31, 2019 $ 1.9 SWEPCo Cash Flow Hedge – Pension Three Months Ended March 31, 2020 Interest Rate and OPEB Total (in millions) Balance in AOCI as of December 31, 2019 $ (1.8 ) $ 0.5 $ (1.3 ) Change in Fair Value Recognized in AOCI — — — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 0.5 — 0.5 Amortization of Prior Service Cost (Credit) — (0.5 ) (0.5 ) Reclassifications from AOCI, before Income Tax (Expense) Benefit 0.5 (0.5 ) — Income Tax (Expense) Benefit 0.1 (0.1 ) — Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 0.4 (0.4 ) — Net Current Period Other Comprehensive Income (Loss) 0.4 (0.4 ) — Balance in AOCI as of March 31, 2020 $ (1.4 ) $ 0.1 $ (1.3 ) Cash Flow Hedge – Pension Three Months Ended March 31, 2019 Interest Rate and OPEB Total (in millions) Balance in AOCI as of December 31, 2018 $ (3.3 ) $ (2.1 ) $ (5.4 ) Change in Fair Value Recognized in AOCI — — — Amount of (Gain) Loss Reclassified from AOCI Interest Expense (b) 0.5 — 0.5 Amortization of Prior Service Cost (Credit) — (0.5 ) (0.5 ) Amortization of Actuarial (Gains) Losses — 0.1 0.1 Reclassifications from AOCI, before Income Tax (Expense) Benefit 0.5 (0.4 ) 0.1 Income Tax (Expense) Benefit 0.1 (0.1 ) — Reclassifications from AOCI, Net of Income Tax (Expense) Benefit 0.4 (0.3 ) 0.1 Net Current Period Other Comprehensive Income (Loss) 0.4 (0.3 ) 0.1 Balance in AOCI as of March 31, 2019 $ (2.9 ) $ (2.4 ) $ (5.3 ) (a) The change in fair value includes $5 million related to AEP's investment in joint venture wind farms acquired as part of the purchase of Sempra Renewables LLC for the three months ended March 31, 2020. (b)

Rate Matters (Tables)

Rate Matters (Tables)	3 Months Ended
	Mar. 31, 2020
Regulated Generating Unit Expected to be Retired by 2020	Plant Gross Investment Accumulated Depreciation Net Investment Accelerated Depreciation Regulatory Asset Materials and Supplies Cost of Removal Regulatory Liability Expected Retirement Date Remaining Recovery Period (dollars in millions) Oklaunion Power Station $ 106.8 $ 92.6 $ 14.2 $ 33.0 (a) $ 3.3 $ 5.2 2020 27 years Dolet Hills Power Station 341.4 205.0 136.4 9.1 (b) 5.8 23.7 2021 27 years (a) In October 2018, PSO changed depreciation rates to utilize the 2020 end-of-life and defer depreciation expense to a regulatory asset for the amount in excess of the previously OCC-approved depreciation rates for Oklaunion Power Station. (b) In January 2020, SWEPCo changed depreciation rates to utilize the 2026 end-of-life and defer depreciation expense to a regulatory asset for the amount in excess of the previously APSC-approved depreciation rates for Dolet Hills Power Station. In March 2020, SWEPCo changed depreciation rates again to utilize the accelerated 2021 end-of-life.
Regulatory Assets Pending Final Regulatory Approval	AEP March 31, December 31, 2020 2019 Noncurrent Regulatory Assets (in millions) Regulatory Assets Currently Earning a Return Plant Retirement Costs – Unrecovered Plant $ 35.2 $ 35.2 Oklaunion Power Station Accelerated Depreciation 33.0 27.4 Kentucky Deferred Purchase Power Expenses 32.9 30.2 Dolet Hills Power Station Accelerated Depreciation 9.1 — Other Regulatory Assets Pending Final Regulatory Approval 2.1 0.7 Regulatory Assets Currently Not Earning a Return Plant Retirement Costs – Asset Retirement Obligation Costs 25.9 30.1 Asset Retirement Obligation 7.7 7.2 Storm-Related Costs 7.3 7.2 Vegetation Management Program (a) 3.8 29.4 Cook Plant Study Costs (b) — 7.6 Other Regulatory Assets Pending Final Regulatory Approval 5.0 6.7 Total Regulatory Assets Pending Final Regulatory Approval (c) $ 162.0 $ 181.7 (a) In April 2020, $26 million of deferred expenses were approved for recovery. See “2019 Texas Base Rate Case” section below for additional information. (b) Approved for recovery in the first quarter of 2020 in the Indiana Base Rate Case. (c) APCo is currently in the process of retiring and replacing its Virginia jurisdictional Automated Meter Reading (AMR) meters with AMI meters. As of March 31, 2020 and December 31, 2019 , APCo has approximately $52 million and $51 million , respectively, of Virginia jurisdictional AMR meters recorded in Total Property, Plant and Equipment - Net on its balance sheets. APCo is pursuing full recovery of these assets through its Virginia depreciation rates. See “2017-2019 Virginia Triennial Review” section below for additional information. AEP Texas March 31, December 31, 2020 2019 Noncurrent Regulatory Assets (in millions) Regulatory Assets Currently Not Earning a Return Vegetation Management Program (a) $ 3.8 $ 29.4 Other Regulatory Assets Pending Final Regulatory Approval 1.5 1.4 Total Regulatory Assets Pending Final Regulatory Approval $ 5.3 $ 30.8 (a) In April 2020, $26 million of deferred expenses were approved for recovery. See “2019 Texas Base Rate Case” section below for additional information. APCo March 31, December 31, 2020 2019 Noncurrent Regulatory Assets (in millions) Regulatory Assets Currently Earning a Return Plant Retirement Costs – Materials and Supplies $ — $ 0.5 Regulatory Assets Currently Not Earning a Return Plant Retirement Costs – Asset Retirement Obligation Costs 25.9 30.1 Total Regulatory Assets Pending Final Regulatory Approval (a) $ 25.9 $ 30.6 (a) APCo is currently in the process of retiring and replacing its Virginia jurisdictional Automated Meter Reading (AMR) meters with AMI meters. As of March 31, 2020 and December 31, 2019 , APCo has approximately $52 million and $51 million , respectively, of Virginia jurisdictional AMR meters recorded in Total Property, Plant and Equipment - Net on its balance sheets. APCo is pursuing full recovery of these assets through its Virginia depreciation rates. See “2017-2019 Virginia Triennial Review” section below for additional information. I&M March 31, December 31, 2020 2019 Noncurrent Regulatory Assets (in millions) Regulatory Assets Currently Not Earning a Return Cook Plant Study Costs (a) $ — $ 7.6 Other Regulatory Assets Pending Final Regulatory Approval — 0.1 Total Regulatory Assets Pending Final Regulatory Approval $ — $ 7.7 (a) Approved for recovery in the first quarter of 2020 in the Indiana Base Rate Case. OPCo March 31, December 31, 2020 2019 Noncurrent Regulatory Assets (in millions) Regulatory Assets Currently Not Earning a Return Other Regulatory Assets Pending Final Regulatory Approval $ 0.1 $ 0.1 Total Regulatory Assets Pending Final Regulatory Approval $ 0.1 $ 0.1 PSO March 31, December 31, 2020 2019 Noncurrent Regulatory Assets (in millions) Regulatory Assets Currently Earning a Return Oklaunion Power Station Accelerated Depreciation $ 33.0 $ 27.4 Regulatory Assets Currently Not Earning a Return Storm-Related Costs 7.3 7.2 Total Regulatory Assets Pending Final Regulatory Approval $ 40.3 $ 34.6 SWEPCo March 31, December 31, 2020 2019 Noncurrent Regulatory Assets (in millions) Regulatory Assets Currently Earning a Return Plant Retirement Costs – Unrecovered Plant, Louisiana $ 35.2 $ 35.2 Dolet Hills Power Station Accelerated Depreciation 9.1 — Other Regulatory Assets Pending Final Regulatory Approval 2.2 0.2 Regulatory Assets Currently Not Earning a Return Asset Retirement Obligation - Louisiana 7.7 7.2 Other Regulatory Assets Pending Final Regulatory Approval 1.9 3.7 Total Regulatory Assets Pending Final Regulatory Approval $ 56.1 $ 46.3

Commitments, Guarantees and C_2

Commitments, Guarantees and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2020
Maximum Future Payments for Letters of Credit Uncommitted Facilities	Company Amount Maturity (in millions) AEP $ 241.2 April 2020 to March 2021 AEP Texas 2.2 July 2020 OPCo (a) 1.0 April 2021 (a) In April 2020, the maturity date was extended from April 2020 to April 2021.
Max Potential Loss on Master Lease Agreements [Table Text Block]	Company Maximum Potential Loss (in millions) AEP $ 48.5 AEP Texas 11.6 APCo 6.6 I&M 4.3 OPCo 7.6 PSO 4.4 SWEPCo 4.9
Future Minimum Lease Payments for Sale and Leaseback [Table Text Block]	Future Minimum Lease Payments AEP (a) I&M (in millions) 2020 $ 147.8 $ 73.9 2021 147.8 73.9 2022 147.5 73.7 Total Future Minimum Lease Payments $ 443.1 $ 221.5 (a) AEP’s future minimum lease payments include equal shares from AEGCo and I&M.

Benefit Plans (Tables)

Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2020
Components of Net Periodic Benefit Cost	AEP Pension Plans OPEB Three Months Ended March 31, Three Months Ended March 31, 2020 2019 2020 2019 (in millions) Service Cost $ 28.0 $ 23.9 $ 2.5 $ 2.4 Interest Cost 42.0 51.1 9.9 12.6 Expected Return on Plan Assets (66.2 ) (74.0 ) (23.9 ) (23.4 ) Amortization of Prior Service Credit — — (17.4 ) (17.3 ) Amortization of Net Actuarial Loss 23.4 14.4 1.5 5.5 Net Periodic Benefit Cost (Credit) $ 27.2 $ 15.4 $ (27.4 ) $ (20.2 ) AEP Texas Pension Plans OPEB Three Months Ended March 31, Three Months Ended March 31, 2020 2019 2020 2019 (in millions) Service Cost $ 2.6 $ 2.1 $ 0.2 $ 0.2 Interest Cost 3.5 4.4 0.8 1.0 Expected Return on Plan Assets (5.7 ) (6.4 ) (2.0 ) (2.0 ) Amortization of Prior Service Credit — — (1.4 ) (1.5 ) Amortization of Net Actuarial Loss 1.9 1.2 0.1 0.5 Net Periodic Benefit Cost (Credit) $ 2.3 $ 1.3 $ (2.3 ) $ (1.8 ) APCo Pension Plans OPEB Three Months Ended March 31, Three Months Ended March 31, 2020 2019 2020 2019 (in millions) Service Cost $ 2.6 $ 2.4 $ 0.3 $ 0.3 Interest Cost 5.1 6.3 1.6 2.2 Expected Return on Plan Assets (8.4 ) (9.4 ) (3.6 ) (3.7 ) Amortization of Prior Service Credit — — (2.5 ) (2.5 ) Amortization of Net Actuarial Loss 2.8 1.8 0.2 0.9 Net Periodic Benefit Cost (Credit) $ 2.1 $ 1.1 $ (4.0 ) $ (2.8 ) I&M Pension Plans OPEB Three Months Ended March 31, Three Months Ended March 31, 2020 2019 2020 2019 (in millions) Service Cost $ 3.9 $ 3.4 $ 0.3 $ 0.3 Interest Cost 4.9 6.0 1.2 1.5 Expected Return on Plan Assets (8.3 ) (9.2 ) (2.9 ) (2.8 ) Amortization of Prior Service Credit — — (2.4 ) (2.4 ) Amortization of Net Actuarial Loss 2.7 1.6 0.2 0.7 Net Periodic Benefit Cost (Credit) $ 3.2 $ 1.8 $ (3.6 ) $ (2.7 ) OPCo Pension Plans OPEB Three Months Ended March 31, Three Months Ended March 31, 2020 2019 2020 2019 (in millions) Service Cost $ 2.4 $ 2.0 $ 0.2 $ 0.2 Interest Cost 3.9 4.7 1.0 1.4 Expected Return on Plan Assets (6.6 ) (7.3 ) (2.6 ) (2.7 ) Amortization of Prior Service Credit — — (1.8 ) (1.7 ) Amortization of Net Actuarial Loss 2.1 1.3 0.2 0.6 Net Periodic Benefit Cost (Credit) $ 1.8 $ 0.7 $ (3.0 ) $ (2.2 ) PSO Pension Plans OPEB Three Months Ended March 31, Three Months Ended March 31, 2020 2019 2020 2019 (in millions) Service Cost $ 1.8 $ 1.6 $ 0.2 $ 0.2 Interest Cost 2.1 2.6 0.5 0.7 Expected Return on Plan Assets (3.6 ) (4.1 ) (1.3 ) (1.3 ) Amortization of Prior Service Credit — — (1.1 ) (1.1 ) Amortization of Net Actuarial Loss 1.2 0.8 0.1 0.3 Net Periodic Benefit Cost (Credit) $ 1.5 $ 0.9 $ (1.6 ) $ (1.2 ) SWEPCo Pension Plans OPEB Three Months Ended March 31, Three Months Ended March 31, 2020 2019 2020 2019 (in millions) Service Cost $ 2.5 $ 2.1 $ 0.2 $ 0.2 Interest Cost 2.5 3.1 0.6 0.8 Expected Return on Plan Assets (3.9 ) (4.4 ) (1.5 ) (1.5 ) Amortization of Prior Service Credit — — (1.3 ) (1.3 ) Amortization of Net Actuarial Loss 1.4 0.9 0.1 0.3 Net Periodic Benefit Cost (Credit) $ 2.5 $ 1.7 $ (1.9 ) $ (1.5 )

Business Segments (Tables)

Business Segments (Tables)	3 Months Ended
	Mar. 31, 2020
Segment Reporting Information [Line Items]
Reportable Segment Information	Three Months Ended March 31, 2020 State Transcos AEPTCo Parent Reconciling Adjustments AEPTCo Consolidated (in millions) Revenues from: External Customers $ 61.3 $ — $ — $ 61.3 Sales to AEP Affiliates 233.7 — — 233.7 Other Revenues 0.6 — — 0.6 Total Revenues $ 295.6 $ — $ — $ 295.6 Interest Income $ 0.2 $ 34.0 $ (33.4 ) (a) $ 0.8 Interest Expense 29.6 33.4 (33.4 ) (a) 29.6 Income Tax Expense 31.8 — — 31.8 Net Income $ 117.3 $ 0.5 (b) $ — $ 117.8 Three Months Ended March 31, 2019 State Transcos AEPTCo Parent Reconciling Adjustments AEPTCo Consolidated (in millions) Revenues from: External Customers $ 50.3 $ — $ — $ 50.3 Sales to AEP Affiliates 193.2 — — 193.2 Total Revenues $ 243.5 $ — $ — $ 243.5 Interest Income $ 0.2 $ 28.4 $ (27.9 ) (a) $ 0.7 Interest Expense 21.7 27.9 (27.9 ) (a) 21.7 Income Tax Expense 27.6 — — 27.6 Net Income $ 104.2 $ 0.1 (b) $ — $ 104.3 March 31, 2020 State Transcos AEPTCo Parent Reconciling Adjustments AEPTCo (in millions) Total Transmission Property $ 10,221.2 $ — $ — $ 10,221.2 Accumulated Depreciation and Amortization 445.8 — — 445.8 Total Transmission Property – Net $ 9,775.4 $ — $ — $ 9,775.4 Notes Receivable - Affiliated $ — $ 3,427.8 $ (3,427.8 ) (c) $ — Total Assets $ 10,150.9 $ 3,562.7 (d) $ (3,513.7 ) (e) $ 10,199.9 Total Long-term Debt $ 3,465.0 $ 3,427.8 $ (3,465.0 ) (c) $ 3,427.8 December 31, 2019 State Transcos AEPTCo Parent Reconciling Adjustments AEPTCo (in millions) 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 (a) Elimination of intercompany interest income/interest expense on affiliated debt arrangement. (b) Includes the elimination of AEPTCo Parent’s equity earnings in the State Transcos. (c) Elimination of intercompany debt. (d) Includes the elimination of AEPTCo Parent’s investments in State Transcos. (e) Primarily relates to the elimination of Notes Receivable from the State Transcos. Three Months Ended March 31, 2020 Vertically Integrated Utilities Transmission and Distribution Utilities AEP Transmission Holdco Generation Corporate and Other (a) Reconciling Adjustments Consolidated (in millions) Revenues from: External Customers $ 2,193.0 $ 1,075.2 $ 73.1 $ 408.4 $ (2.2 ) $ — $ 3,747.5 Other Operating Segments 33.7 31.7 237.1 30.2 22.1 (354.8 ) — Total Revenues $ 2,226.7 $ 1,106.9 $ 310.2 $ 438.6 $ 19.9 $ (354.8 ) $ 3,747.5 Net Income (Loss) $ 246.3 $ 116.2 $ 141.6 $ 30.5 $ (35.3 ) $ — $ 499.3 Three Months Ended March 31, 2019 Vertically Integrated Utilities Transmission and Distribution Utilities AEP Transmission Holdco Generation Corporate and Other (a) Reconciling Adjustments Consolidated (in millions) Revenues from: External Customers $ 2,372.3 $ 1,179.8 $ 61.2 $ 439.7 $ 3.8 $ — $ 4,056.8 Other Operating Segments 31.0 42.2 195.2 42.1 21.7 (332.2 ) — Total Revenues $ 2,403.3 $ 1,222.0 $ 256.4 $ 481.8 $ 25.5 $ (332.2 ) $ 4,056.8 Net Income (Loss) $ 303.6 $ 156.5 $ 125.2 $ 39.2 $ (50.4 ) $ — $ 574.1 March 31, 2020 Vertically Integrated Utilities Transmission and Distribution Utilities AEP Transmission Holdco Generation Corporate and Other (a) Reconciling Consolidated (in millions) Total Property, Plant and Equipment $ 47,764.3 $ 20,182.8 $ 10,662.9 $ 1,753.2 $ 408.3 $ (354.5 ) (b) $ 80,417.0 Accumulated Depreciation and Amortization 14,821.8 3,964.6 464.0 116.9 187.3 (186.5 ) (b) 19,368.1 Total Property Plant and Equipment - Net $ 32,942.5 $ 16,218.2 $ 10,198.9 $ 1,636.3 $ 221.0 $ (168.0 ) (b) $ 61,048.9 Total Assets $ 41,020.5 $ 18,892.5 $ 11,484.8 $ 3,216.4 $ 7,033.6 (c) $ (3,923.8 ) (b) (d) $ 77,724.0 Long-term Debt Due Within One Year: Affiliated $ 20.0 $ — $ — $ — $ — $ (20.0 ) $ — Nonaffiliated 1,316.3 289.0 — — 504.4 (e) — 2,109.7 Long-term Debt: Affiliated 39.0 — — — — (39.0 ) — Nonaffiliated 11,641.0 6,585.5 3,600.3 — 3,956.2 (e) — 25,783.0 Total Long-term Debt $ 13,016.3 $ 6,874.5 $ 3,600.3 $ — $ 4,460.6 $ (59.0 ) $ 27,892.7 December 31, 2019 Vertically Integrated Utilities Transmission and Distribution Utilities AEP Transmission Holdco Generation Corporate and Other (a) Reconciling Consolidated (in millions) Total Property, Plant and Equipment $ 47,323.7 $ 19,773.3 $ 10,334.0 $ 1,650.8 $ 418.4 $ (354.5 ) (b) $ 79,145.7 Accumulated Depreciation and Amortization 14,580.4 3,911.2 418.9 99.0 184.5 (186.4 ) (b) 19,007.6 Total Property Plant and Equipment - Net $ 32,743.3 $ 15,862.1 $ 9,915.1 $ 1,551.8 $ 233.9 $ (168.1 ) (b) $ 60,138.1 Total Assets $ 41,228.8 $ 18,757.5 $ 11,143.5 $ 3,123.8 $ 5,440.0 (c) $ (3,801.3 ) (b) (d) $ 75,892.3 Long-term Debt Due Within One Year: Affiliated $ 20.0 $ — $ — $ — $ — $ (20.0 ) $ — Nonaffiliated 704.7 392.2 — — 501.8 (e) — 1,598.7 Long-term Debt: Affiliated 39.0 — — — — (39.0 ) — Nonaffiliated 12,162.0 6,248.1 3,593.8 — 3,122.9 (e) — 25,126.8 Total Long-term Debt $ 12,925.7 $ 6,640.3 $ 3,593.8 $ — $ 3,624.7 $ (59.0 ) $ 26,725.5 (a) Corporate and Other primarily includes the purchasing of receivables from certain AEP utility subsidiaries. This segment also includes Parent’s guarantee revenue received from affiliates, investment income, interest income, interest expense and other nonallocated costs. (b) Includes eliminations due to an intercompany finance lease. (c) Includes elimination of AEP Parent’s investments in wholly-owned subsidiary companies. (d) Reconciling Adjustments for Total Assets primarily include elimination of intercompany advances to affiliates and intercompany accounts receivable. (e) Amounts reflect the impact of fair value hedge accounting. See “Accounting for Fair Value Hedging Strategies” section of Note 10 for additional information.

Derivatives and Hedging (Tables

Derivatives and Hedging (Tables)	3 Months Ended
	Mar. 31, 2020
Notional Volume of Derivative Instruments	Notional Volume of Derivative Instruments March 31, 2020 Primary Risk Exposure Unit of Measure AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Commodity: Power MWhs 305.4 — 38.7 18.5 3.2 5.9 1.7 Natural Gas MMBtus 42.3 — — — — — 10.7 Heating Oil and Gasoline Gallons 5.0 1.3 0.8 0.5 1.0 0.5 0.7 Interest Rate USD $ 137.1 $ — $ — $ — $ — $ — $ — Interest Rate on Long-term Debt USD $ 650.0 $ — $ 150.0 $ — $ — $ — $ — December 31, 2019 Primary Risk Exposure Unit of Measure AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Commodity: Power MWhs 365.9 — 61.0 26.8 7.1 14.9 4.4 Natural Gas MMBtus 40.7 — — — — — 11.6 Heating Oil and Gasoline Gallons 6.9 1.8 1.1 0.6 1.4 0.7 0.9 Interest Rate USD $ 140.1 $ — $ — $ — $ — $ — $ — Interest Rate on Long-term Debt USD $ 625.0 $ — $ — $ — $ — $ — $ —
Fair Value of Derivative Instruments	AEP Fair Value of Derivative Instruments March 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 $ 412.7 $ 13.5 $ 4.6 $ 430.8 $ (300.4 ) $ 130.4 Long-term Risk Management Assets 331.6 13.5 52.7 397.8 (74.1 ) 323.7 Total Assets 744.3 27.0 57.3 828.6 (374.5 ) 454.1 Current Risk Management Liabilities 401.7 103.2 5.3 510.2 (353.4 ) 156.8 Long-term Risk Management Liabilities 305.9 82.9 — 388.8 (96.9 ) 291.9 Total Liabilities 707.6 186.1 5.3 899.0 (450.3 ) 448.7 Total MTM Derivative Contract Net Assets (Liabilities) $ 36.7 $ (159.1 ) $ 52.0 $ (70.4 ) $ 75.8 $ 5.4 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 Fair Value of Derivative Instruments March 31, 2020 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) Financial Position (c) (in millions) Current Risk Management Assets $ — $ — $ — Long-term Risk Management Assets — — — Total Assets — — — Current Risk Management Liabilities 1.2 (1.2 ) — Long-term Risk Management Liabilities — — — Total Liabilities 1.2 (1.2 ) — Total MTM Derivative Contract Net Assets (Liabilities) $ (1.2 ) $ 1.2 $ — December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) 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 Fair Value of Derivative Instruments March 31, 2020 Risk Management Hedging Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Interest Rate (a) Financial Position (b) Financial Position (c) (in millions) Current Risk Management Assets $ 71.1 $ 0.3 $ (53.3 ) $ 18.1 Long-term Risk Management Assets 3.5 — (3.4 ) 0.1 Total Assets 74.6 0.3 (56.7 ) 18.2 Current Risk Management Liabilities 68.3 5.3 (58.6 ) 15.0 Long-term Risk Management Liabilities 3.5 — (3.4 ) 0.1 Total Liabilities 71.8 5.3 (62.0 ) 15.1 Total MTM Derivative Contract Net Assets (Liabilities) $ 2.8 $ (5.0 ) $ 5.3 $ 3.1 December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) Financial Position (c) (in millions) Current Risk Management Assets $ 124.4 $ (85.0 ) $ 39.4 Long-term Risk Management Assets 0.9 (0.8 ) 0.1 Total Assets 125.3 (85.8 ) 39.5 Current Risk Management Liabilities 86.2 (84.3 ) 1.9 Long-term Risk Management Liabilities 0.7 (0.7 ) — Total Liabilities 86.9 (85.0 ) 1.9 Total MTM Derivative Contract Net Assets (Liabilities) $ 38.4 $ (0.8 ) $ 37.6 I&M Fair Value of Derivative Instruments March 31, 2020 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) Financial Position (c) (in millions) Current Risk Management Assets $ 42.3 $ (35.6 ) $ 6.7 Long-term Risk Management Assets 2.1 (2.0 ) 0.1 Total Assets 44.4 (37.6 ) 6.8 Current Risk Management Liabilities 38.3 (36.6 ) 1.7 Long-term Risk Management Liabilities 2.1 (2.0 ) 0.1 Total Liabilities 40.4 (38.6 ) 1.8 Total MTM Derivative Contract Net Assets $ 4.0 $ 1.0 $ 5.0 December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) Financial Position (c) (in millions) Current Risk Management Assets $ 66.9 $ (57.1 ) $ 9.8 Long-term Risk Management Assets 0.5 (0.4 ) 0.1 Total Assets 67.4 (57.5 ) 9.9 Current Risk Management Liabilities 55.2 (54.7 ) 0.5 Long-term Risk Management Liabilities 0.4 (0.4 ) — Total Liabilities 55.6 (55.1 ) 0.5 Total MTM Derivative Contract Net Assets (Liabilities) $ 11.8 $ (2.4 ) $ 9.4 OPCo Fair Value of Derivative Instruments March 31, 2020 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) Financial Position (c) (in millions) Current Risk Management Assets $ — $ — $ — Long-term Risk Management Assets — — — Total Assets — — — Current Risk Management Liabilities 9.6 (0.9 ) 8.7 Long-term Risk Management Liabilities 112.2 — 112.2 Total Liabilities 121.8 (0.9 ) 120.9 Total MTM Derivative Contract Net Assets (Liabilities) $ (121.8 ) $ 0.9 $ (120.9 ) December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) 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 Fair Value of Derivative Instruments March 31, 2020 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) Financial Position (c) (in millions) Current Risk Management Assets $ 6.7 $ (0.3 ) $ 6.4 Long-term Risk Management Assets — — — Total Assets 6.7 (0.3 ) 6.4 Current Risk Management Liabilities 0.9 (0.8 ) 0.1 Long-term Risk Management Liabilities — — — Total Liabilities 0.9 (0.8 ) 0.1 Total MTM Derivative Contract Net Assets $ 5.8 $ 0.5 $ 6.3 December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) 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 Fair Value of Derivative Instruments March 31, 2020 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) Financial Position (c) (in millions) Current Risk Management Assets $ 2.7 $ (0.1 ) $ 2.6 Long-term Risk Management Assets — — — Total Assets 2.7 (0.1 ) 2.6 Current Risk Management Liabilities 2.9 (0.7 ) 2.2 Long-term Risk Management Liabilities 2.9 — 2.9 Total Liabilities 5.8 (0.7 ) 5.1 Total MTM Derivative Contract Net Assets (Liabilities) $ (3.1 ) $ 0.6 $ (2.5 ) December 31, 2019 Risk Management Gross Amounts Offset Net Amounts of Assets/Liabilities Contracts – in the Statement of Presented in the Statement of Balance Sheet Location Commodity (a) Financial Position (b) 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	Amount of Gain (Loss) Recognized on Risk Management Contracts Three Months Ended March 31, 2020 Location of Gain (Loss) AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Vertically Integrated Utilities Revenues $ 0.4 $ — $ — $ — $ — $ — $ — Generation & Marketing Revenues (10.3 ) — — — — — — Electric Generation, Transmission and Distribution Revenues — — 0.2 0.1 — — — Purchased Electricity for Resale 0.1 — 0.1 — — — — Other Operation (0.2 ) (0.1 ) — — (0.1 ) — — Maintenance (0.2 ) (0.1 ) (0.1 ) — — — — Regulatory Assets (a) (33.9 ) (1.2 ) (8.9 ) (0.7 ) (18.4 ) (0.5 ) (2.0 ) Regulatory Liabilities (a) 11.2 — (7.3 ) 3.2 3.5 8.1 3.3 Total Gain (Loss) on Risk Management Contracts $ (32.9 ) $ (1.4 ) $ (16.0 ) $ 2.6 $ (15.0 ) $ 7.6 $ 1.3 Three Months Ended March 31, 2019 Location of Gain (Loss) AEP AEP Texas APCo I&M OPCo PSO SWEPCo (in millions) Vertically Integrated Utilities Revenues $ 0.3 $ — $ — $ — $ — $ — $ — Generation & Marketing Revenues 2.7 — — — — — — Electric Generation, Transmission and Distribution Revenues — — (0.1 ) 0.3 — — 0.1 Purchased Electricity for Resale 1.4 — — — — — — Other Operation (0.4 ) (0.1 ) (0.1 ) — (0.1 ) — — Maintenance (0.5 ) (0.1 ) — — (0.1 ) — (0.1 ) Regulatory Assets (a) (6.4 ) 0.6 (2.1 ) 0.3 (8.9 ) 0.5 (0.1 ) Regulatory Liabilities (a) (22.0 ) — (31.7 ) 6.6 — 6.2 4.7 Total Gain (Loss) on Risk Management Contracts $ (24.9 ) $ 0.4 $ (34.0 ) $ 7.2 $ (9.1 ) $ 6.7 $ 4.6 (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 the Condensed Balance Sheet	Carrying Amount of the Hedged Liabilities Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Liabilities March 31, 2020 December 31, 2019 March 31, 2020 December 31, 2019 (in millions) Long-term Debt (a) $ (553.4 ) $ (510.8 ) $ (57.0 ) $ (14.5 ) (a) Amounts included on the balance sheets within Long-term Debt Due within One Year and Long-term Debt, respectively.
Gain (Loss) on Hedging Instruments	Three Months Ended March 31, 2020 2019 (in millions) Gain (Loss) on Interest Rate Contracts: Gain on Fair Value Hedging Instruments (a) $ 42.5 $ 11.1 Loss on Fair Value Portion of Long-term Debt (a) (42.5 ) (11.1 ) (a) Gain (Loss) is included in Interest Expense on the statements of income.
Impact of Cash Flow Hedges on the Condensed Balance Sheet	Impact of Cash Flow Hedges on AEP’s Balance Sheets March 31, 2020 December 31, 2019 Commodity Interest Rate Commodity Interest Rate (in millions) AOCI Gain (Loss) Net of Tax $ (128.5 ) $ (53.5 ) $ (103.5 ) $ (11.5 ) Portion Expected to be Reclassed to Net Income During the Next Twelve Months (73.2 ) (4.3 ) (51.7 ) (2.1 ) Impact of Cash Flow Hedges on the Registrant Subsidiaries’ Balance Sheets March 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 $ (3.1 ) $ (1.1 ) $ (3.4 ) $ (1.1 ) APCo (3.3 ) 1.1 0.9 0.9 I&M (9.5 ) (1.6 ) (9.9 ) (1.6 ) PSO 0.9 0.9 1.1 1.0 SWEPCo (1.4 ) (1.5 ) (1.8 ) (1.5 )
Liabilities Subject to Cross Default Provisions	March 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 $ 310.4 $ 1.6 $ 282.9 APCo 2.2 — 0.2 I&M 1.3 — 0.1 SWEPCo 5.5 — 5.5 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)	3 Months Ended
	Mar. 31, 2020
Book Values and Fair Values of Long-term Debt	March 31, 2020 December 31, 2019 Company Book Value Fair Value Book Value Fair Value (in millions) AEP (a) $ 27,892.7 $ 29,776.6 $ 26,725.5 $ 30,172.0 AEP Texas 4,445.4 4,637.3 4,558.4 4,981.5 AEPTCo 3,427.8 3,680.7 3,427.3 3,868.0 APCo 4,352.4 4,959.0 4,363.8 5,253.1 I&M 3,028.0 3,318.2 3,050.2 3,453.8 OPCo 2,429.1 2,795.3 2,082.0 2,554.3 PSO 1,386.3 1,553.9 1,386.2 1,603.3 SWEPCo 2,654.4 2,776.5 2,655.6 2,927.9 (a) The fair value amount includes debt related to AEP’s Equity Units issued in March 2019 and has a fair value of $777 million and $871 million as of March 31, 2020 and December 31, 2019 , respectively. See “Equity Units” section of Note 12 for additional information.
Other Temporary Investments	March 31, 2020 Gross Gross Unrealized Unrealized Fair Other Temporary Investments Cost Gains Losses Value (in millions) Restricted Cash and Other Cash Deposits (a) $ 151.9 $ — $ — $ 151.9 Fixed Income Securities – Mutual Funds (b) 118.6 0.4 — 119.0 Equity Securities – Mutual Funds 19.3 11.2 — 30.5 Total Other Temporary Investments $ 289.8 $ 11.6 $ — $ 301.4 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	Three Months Ended March 31, 2020 2019 (in millions) Proceeds from Investment Sales $ 23.2 $ — Purchases of Investments 6.7 0.1 Gross Realized Gains on Investment Sales 2.0 — Gross Realized Losses on Investment Sales 0.1 —
Nuclear Trust Fund Investments	March 31, 2020 December 31, 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 $ 46.9 $ — $ — $ 15.3 $ — $ — Fixed Income Securities: United States Government 1,026.1 121.4 (5.6 ) 1,112.5 55.5 (6.1 ) Corporate Debt 62.7 6.0 (1.6 ) 72.4 5.3 (1.6 ) State and Local Government 149.7 1.5 (0.2 ) 7.6 0.7 (0.2 ) Subtotal Fixed Income Securities 1,238.5 128.9 (7.4 ) 1,192.5 61.5 (7.9 ) Equity Securities - Domestic (a) 1,393.8 777.6 — 1,767.9 1,144.4 — Spent Nuclear Fuel and Decommissioning Trusts $ 2,679.2 $ 906.5 $ (7.4 ) $ 2,975.7 $ 1,205.9 $ (7.9 ) (a) Amount reported as Gross Unrealized Gains includes unrealized gains of $801 million and $1.1 billion and unrealized losses of $23 million and $5 million as of March 31, 2020 and December 31, 2019 , respectively.
Securities Activity Within the Decommissioning and SNF Trusts	Three Months Ended March 31, 2020 2019 (in millions) Proceeds from Investment Sales $ 612.4 $ 111.9 Purchases of Investments 626.0 130.3 Gross Realized Gains on Investment Sales 10.9 12.3 Gross Realized Losses on Investment Sales 17.0 13.8
Contractual Maturities, Fair Value of Debt Securities in Nuclear Trusts	Fair Value of Fixed Income Securities (in millions) Within 1 year $ 238.9 After 1 year through 5 years 404.5 After 5 years through 10 years 282.5 After 10 years 312.6 Total $ 1,238.5
Fair Value, Assets and Liabilities Measured on Recurring Basis	AEP Assets and Liabilities Measured at Fair Value on a Recurring Basis March 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Other Temporary Investments Restricted Cash and Other Cash Deposits (a) $ 128.1 $ — $ — $ 23.8 $ 151.9 Fixed Income Securities – Mutual Funds 119.0 — — — 119.0 Equity Securities – Mutual Funds (b) 30.5 — — — 30.5 Total Other Temporary Investments 277.6 — — 23.8 301.4 Risk Management Assets Risk Management Commodity Contracts (c) (d) 3.7 369.8 346.1 (340.5 ) 379.1 Cash Flow Hedges: Commodity Hedges (c) — 18.7 4.2 (5.2 ) 17.7 Interest Rate Hedges — 0.3 — — 0.3 Fair Value Hedges — 57.0 — — 57.0 Total Risk Management Assets 3.7 445.8 350.3 (345.7 ) 454.1 Spent Nuclear Fuel and Decommissioning Trusts Cash and Cash Equivalents (e) 37.0 — — 9.9 46.9 Fixed Income Securities: United States Government — 1,026.1 — — 1,026.1 Corporate Debt — 62.7 — — 62.7 State and Local Government — 149.7 — — 149.7 Subtotal Fixed Income Securities — 1,238.5 — — 1,238.5 Equity Securities – Domestic (b) 1,393.8 — — — 1,393.8 Total Spent Nuclear Fuel and Decommissioning Trusts 1,430.8 1,238.5 — 9.9 2,679.2 Total Assets $ 1,712.1 $ 1,684.3 $ 350.3 $ (312.0 ) $ 3,434.7 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (d) $ 4.9 $ 410.1 $ 267.9 $ (416.3 ) $ 266.6 Cash Flow Hedges: Commodity Hedges (c) — 142.1 39.9 (5.2 ) 176.8 Interest Rate Hedges — 5.3 — — 5.3 Total Risk Management Liabilities $ 4.9 $ 557.5 $ 307.8 $ (421.5 ) $ 448.7 AEP Assets and Liabilities Measured at Fair Value on a Recurring Basis December 31, 2019 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Other Temporary Investments Restricted Cash and Other Cash Deposits (a) $ 197.6 $ — $ — $ 17.1 $ 214.7 Fixed Income Securities – Mutual Funds 123.3 — — — 123.3 Equity Securities – Mutual Funds (b) 50.5 — — — 50.5 Total Other Temporary Investments 371.4 — — 17.1 388.5 Risk Management Assets Risk Management Commodity Contracts (c) (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 Assets and Liabilities Measured at Fair Value on a Recurring Basis March 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 100.1 $ — $ — $ — $ 100.1 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) $ — $ 1.2 $ — $ (1.2 ) $ — December 31, 2019 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 154.7 $ — $ — $ — $ 154.7 APCo Assets and Liabilities Measured at Fair Value on a Recurring Basis March 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Restricted Cash for Securitized Funding $ 15.7 $ — $ — $ — $ 15.7 Risk Management Assets Risk Management Commodity Contracts (c) (g) — 55.0 17.1 (54.2 ) 17.9 Cash Flow Hedges: Interest Rate Hedges — 0.3 — — 0.3 Total Risk Management Assets — 55.3 17.1 (54.2 ) 18.2 Total Assets $ 15.7 $ 55.3 $ 17.1 $ (54.2 ) $ 33.9 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 58.8 $ 10.5 $ (59.5 ) $ 9.8 Cash Flow Hedges: Interest Rate Hedges — 5.3 — — 5.3 Total Risk Management Liabilities $ — $ 64.1 $ 10.5 $ (59.5 ) $ 15.1 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 Assets and Liabilities Measured at Fair Value on a Recurring Basis March 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ 38.1 $ 4.9 $ (36.2 ) $ 6.8 Spent Nuclear Fuel and Decommissioning Trusts Cash and Cash Equivalents (e) 37.0 — — 9.9 46.9 Fixed Income Securities: United States Government — 1,026.1 — — 1,026.1 Corporate Debt — 62.7 — — 62.7 State and Local Government — 149.7 — — 149.7 Subtotal Fixed Income Securities — 1,238.5 — — 1,238.5 Equity Securities - Domestic (b) 1,393.8 — — — 1,393.8 Total Spent Nuclear Fuel and Decommissioning Trusts 1,430.8 1,238.5 — 9.9 2,679.2 Total Assets $ 1,430.8 $ 1,276.6 $ 4.9 $ (26.3 ) $ 2,686.0 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 36.2 $ 2.8 $ (37.2 ) $ 1.8 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 Assets and Liabilities Measured at Fair Value on a Recurring Basis March 31, 2020 Level 1 Level 2 Level 3 Other Total Liabilities: (in millions) Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 0.9 $ 120.9 $ (0.9 ) $ 120.9 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 Assets and Liabilities Measured at Fair Value on a Recurring Basis March 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ — $ 6.7 $ (0.3 ) $ 6.4 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 0.5 $ 0.4 $ (0.8 ) $ 0.1 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 Assets and Liabilities Measured at Fair Value on a Recurring Basis March 31, 2020 Level 1 Level 2 Level 3 Other Total Assets: (in millions) Risk Management Assets Risk Management Commodity Contracts (c) (g) $ — $ — $ 2.7 $ (0.1 ) $ 2.6 Liabilities: Risk Management Liabilities Risk Management Commodity Contracts (c) (g) $ — $ 0.6 $ 5.2 $ (0.7 ) $ 5.1 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 March 31, 2020 maturity of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), is as follows: Level 1 matures $(1) million in periods 2021-2023; Level 2 matures $(30) million in 2020, $(9) million in periods 2021-2023 and $(1) million in periods 2024-2025; Level 3 matures $37 million in 2020, $36 million in periods 2021-2023, $25 million in periods 2024-2025 and $(20) million in periods 2026-2032. Risk management commodity contracts are substantially comprised of power contracts. (e) Amounts in “Other’’ column primarily represent accrued interest receivables from financial institutions. Level 1 amounts primarily represent investments in money market funds. (f) The December 31, 2019 maturity of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), is as follows: Level 2 matures $(7) million in 2020 and $(3) million in periods 2021-2023; Level 3 matures $96 million in 2020, $36 million in periods 2021-2023, $25 million in periods 2024-2025 and $(12) million in periods 2026-2032. Risk management commodity contracts are substantially comprised of power contracts. (g) Substantially comprised of power contracts for the Registrant Subsidiaries.
Changes in Fair Value of Net Trading Derivatives and Other Investments	Three Months Ended March 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) 0.9 (9.2 ) 0.2 (0.3 ) 8.0 1.9 Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date (a) 10.9 — — — — — Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income (c) (4.1 ) — — — — — Settlements (59.2 ) (21.9 ) (4.0 ) 2.5 (17.7 ) (5.3 ) Transfers into Level 3 (d) (e) (0.5 ) — — — — — Transfers out of Level 3 (e) 5.3 0.7 0.4 — — — Changes in Fair Value Allocated to Regulated Jurisdictions (f) (20.7 ) (0.7 ) (0.3 ) (19.5 ) 0.2 (0.5 ) Balance as of March 31, 2020 $ 42.5 $ 6.6 $ 2.1 $ (120.9 ) $ 6.3 $ (2.5 ) Three Months Ended March 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) (23.0 ) (29.0 ) — (0.4 ) 6.8 3.3 Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date (a) 8.5 — — — — — Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income (c) (15.8 ) — — — — — Settlements (54.5 ) (17.8 ) (5.1 ) 1.8 (13.0 ) (7.3 ) Transfers into Level 3 (d) (e) 0.1 — — — — — Transfers out of Level 3 (e) (1.2 ) (0.7 ) (0.4 ) — — — Changes in Fair Value Allocated to Regulated Jurisdictions (f) (7.2 ) (2.9 ) 1.0 (8.1 ) 1.1 1.7 Balance as of March 31, 2019 $ 38.1 $ 7.4 $ 4.4 $ (106.1 ) $ 4.4 $ — (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 Significant Unobservable Inputs March 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input Low High Average (c) (in millions) Energy Contracts $ 321.2 $ 284.6 Discounted Cash Flow Forward Market Price (a) $ (0.05 ) $ 135.24 $ 29.17 Natural Gas Contracts — 5.1 Discounted Cash Flow Forward Market Price (b) 1.37 2.51 2.13 FTRs 29.1 18.1 Discounted Cash Flow Forward Market Price (a) (10.12 ) 4.17 (0.31 ) Total $ 350.3 $ 307.8 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 Significant Unobservable Inputs March 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ 5.3 $ 2.2 Discounted Cash Flow Forward Market Price $ 9.95 $ 42.15 $ 21.81 FTRs 11.8 8.3 Discounted Cash Flow Forward Market Price — 3.44 0.42 Total $ 17.1 $ 10.5 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 Significant Unobservable Inputs March 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ 3.2 $ 1.3 Discounted Cash Flow Forward Market Price $ 9.95 $ 42.15 $ 21.81 FTRs 1.7 1.5 Discounted Cash Flow Forward Market Price (0.51 ) 2.77 0.12 Total $ 4.9 $ 2.8 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 Significant Unobservable Inputs March 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) Energy Contracts $ — $ 120.9 Discounted Cash Flow Forward Market Price $ 12.57 $ 42.71 $ 26.31 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 Significant Unobservable Inputs March 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input (a) Low High Average (c) (in millions) FTRs $ 6.7 $ 0.4 Discounted Cash Flow Forward Market Price $ (7.07 ) $ 0.95 $ (2.38 ) 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 Significant Unobservable Inputs March 31, 2020 Significant Input/Range Fair Value Valuation Unobservable Weighted Assets Liabilities Technique Input Low High Average (c) (in millions) Natural Gas Contracts $ — $ 5.1 Discounted Cash Flow Forward Market Price (b) $ 1.37 $ 2.51 $ 2.13 FTRs 2.7 0.1 Discounted Cash Flow Forward Market Price (a) (7.07 ) 0.95 (2.38 ) Total $ 2.7 $ 5.2 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.
Sensitivity of Fair Value Measurements	Uncertainty of Fair Value Measurements Significant Unobservable Input Position Change in Input Impact on Fair Value Measurement Forward Market Price Buy Increase (Decrease) Higher (Lower) Forward Market Price Sell Increase (Decrease) Lower (Higher)

Income Taxes (Tables)

Income Taxes (Tables)	3 Months Ended
	Mar. 31, 2020
Schedule of Effective Income Tax Rate Reconciliation	Three Months Ended March 31, 2020 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo U.S. Federal Statutory Rate 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % Increase (decrease) due to: State Income Tax, net of Federal benefit 2.5 % 1.5 % 2.9 % 3.0 % 3.2 % 0.7 % 4.6 % 2.7 % Tax Reform Excess ADIT Reversal (9.4 )% (6.2 )% 0.4 % (13.0 )% (19.6 )% (10.2 )% (23.1 )% (94.7 )% Production and Investment Tax Credits (4.3 )% (0.4 )% — % — % (1.9 )% — % (1.3 )% (0.5 )% Flow Through 0.5 % 0.1 % 0.5 % 1.5 % 0.2 % 1.0 % 0.6 % (1.0 )% AFUDC Equity (1.4 )% (2.6 )% (2.6 )% (1.0 )% (1.1 )% (1.0 )% (0.7 )% (0.4 )% Parent Company Loss Benefit — % (0.2 )% (0.9 )% (3.3 )% (3.9 )% (0.1 )% (2.2 )% (2.4 )% Discrete Tax Adjustments — % — % — % — % 2.7 % — % — % — % Other (0.4 )% 0.3 % — % 0.1 % (0.2 )% — % 0.1 % 7.2 % Effective Income Tax Rate 8.5 % 13.5 % 21.3 % 8.3 % 0.4 % 11.4 % (1.0 )% (68.1 )% Three Months Ended March 31, 2019 AEP AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo U.S. Federal Statutory Rate 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % Increase (decrease) due to: State Income Tax, net of Federal benefit 2.1 % 1.5 % 2.9 % 3.4 % 2.0 % 0.9 % 4.6 % 0.2 % Tax Reform Excess ADIT Reversal (13.6 )% (7.6 )% 0.4 % (42.2 )% (17.4 )% (7.6 )% (21.9 )% (17.0 )% Production and Investment Tax Credits (2.2 )% (1.0 )% — % — % (2.0 )% — % (1.7 )% (0.8 )% Flow Through (0.2 )% 0.3 % 0.2 % (0.9 )% (2.4 )% 0.7 % 0.6 % (0.9 )% AFUDC Equity (1.4 )% (1.6 )% (2.5 )% (1.0 )% (1.9 )% (0.7 )% (0.4 )% (1.1 )% Parent Company Loss — % (2.3 )% (1.0 )% (2.4 )% (1.8 )% (1.1 )% (1.8 )% (0.5 )% Discrete Tax Adjustments 1.7 % — % — % 0.4 % — % — % — % — % Other (0.2 )% 0.1 % (0.1 )% (0.3 )% (0.3 )% 0.2 % 0.2 % 1.5 % Effective Income Tax Rate 7.2 % 10.4 % 20.9 % (22.0 )% (2.8 )% 13.4 % 0.6 % 2.4 %

Financing Activities (Tables)

Financing Activities (Tables)	3 Months Ended
	Mar. 31, 2020
Long-term Debt	Type of Debt March 31, 2020 December 31, 2019 (in millions) Senior Unsecured Notes $ 22,515.8 $ 21,180.7 Pollution Control Bonds 1,999.2 1,998.8 Notes Payable 209.4 234.3 Securitization Bonds 899.1 1,025.1 Spent Nuclear Fuel Obligation (a) 280.9 279.8 Junior Subordinated Notes (b) 788.6 787.8 Other Long-term Debt 1,199.7 1,219.0 Total Long-term Debt Outstanding 27,892.7 26,725.5 Long-term Debt Due Within One Year 2,109.7 1,598.7 Long-term Debt $ 25,783.0 $ 25,126.8 (a) Pursuant to the Nuclear Waste Policy Act of 1982, I&M, a nuclear licensee, has an obligation to the United States Department of Energy for SNF disposal. The obligation includes a one-time fee for nuclear fuel consumed prior to April 7, 1983. Trust fund assets related to this obligation were $324 million and $323 million as of March 31, 2020 and December 31, 2019 , respectively, and are included in Spent Nuclear Fuel and Decommissioning Trusts on the balance sheets. (b) See “Equity Units” section below for additional information.
Long-term Debt Issuances	Principal Interest Company Type of Debt Amount (a) Rate Due Date Issuances: (in millions) (%) AEP Senior Unsecured Notes $ 400.0 2.30 2030 AEP Senior Unsecured Notes 400.0 3.25 2050 OPCo Senior Unsecured Notes 350.0 2.60 2030 Non-Registrant: KPCo Other Long-term Debt 125.0 Variable 2022 Transource Energy Other Long-term Debt 5.0 Variable 2023 Transource Energy Senior Unsecured Notes 150.0 2.75 2050 Total Issuances $ 1,430.0 (a) Amounts indicated on the statements of cash flows are net of issuance costs and premium or discount and will not tie to the issuance amounts.
Retirements and Principal Payments	Principal Interest Company Type of Debt Amount Paid Rate Due Date Retirements and Principal Payments: (in millions) (%) AEP Texas Securitization Bonds $ 111.0 5.31 2020 AEP Texas Securitization Bonds 3.3 2.06 2025 APCo Securitization Bonds 12.2 2.01 2023 I&M Notes Payable 0.7 Variable 2020 I&M Notes Payable 1.5 Variable 2021 I&M Notes Payable 5.1 Variable 2022 I&M Notes Payable 3.8 Variable 2022 I&M Notes Payable 6.2 Variable 2023 I&M Notes Payable 6.0 Variable 2024 I&M Other Long-term Debt 0.4 6.00 2025 PSO Other Long-term Debt 0.1 3.00 2027 SWEPCo Notes Payable 1.6 4.58 2032 Non-Registrant: Transource Energy Other Long-term Debt 148.6 Variable 2023 Total Retirements and Principal Payments $ 300.5
Utility Money Pool Participants' Money Pool Activity and Authorized Borrowing Limits	Maximum Average Net 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 March 31, 2020 Limit (in millions) AEP Texas $ 63.9 $ 199.7 $ 39.0 $ 90.3 $ (63.9 ) $ 500.0 AEPTCo 358.4 69.8 257.6 32.6 (261.0 ) 820.0 (a) APCo 373.5 22.2 303.1 22.0 (333.5 ) 500.0 I&M 147.5 13.3 108.4 13.3 (90.4 ) 500.0 OPCo 353.9 32.8 191.5 25.2 (29.4 ) 500.0 PSO 70.9 57.1 25.3 28.4 (70.9 ) 300.0 SWEPCo 152.8 — 105.5 — (148.1 ) 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	Maximum Loans Average Loans Loans to the Nonutility to the Nonutility to the Nonutility Money Pool as of Company Money Pool Money Pool March 31, 2020 (in millions) AEP Texas $ 7.5 $ 7.2 $ 7.1 SWEPCo 2.1 2.1 2.1
Direct Borrowing Activity	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 March 31, 2020 March 31, 2020 Borrowing Limit (in millions) $ 1.4 $ 190.3 $ 1.4 $ 125.1 $ 1.3 $ 93.3 $ 50.0 (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	Three Months Ended March 31, 2020 2019 Maximum Interest Rate 2.24 % 3.02 % Minimum Interest Rate 1.76 % 2.73 %
Average Interest Rates for Funds Borrowed from and Loaned to Utility Money Pool	Average Interest Rate for Funds Average Interest Rate for Funds Borrowed from the Utility Money Pool Loaned to the Utility Money Pool for Three Months Ended March 31, for Three Months Ended March 31, Company 2020 2019 2020 2019 AEP Texas 2.05 % 2.86 % 1.97 % — % AEPTCo 1.95 % 2.83 % 1.91 % 2.90 % APCo 1.95 % 2.92 % 1.94 % 2.79 % I&M 1.95 % 2.80 % 1.94 % 2.87 % OPCo 1.90 % 2.85 % 2.06 % — % PSO 2.00 % 2.89 % 1.95 % — % SWEPCo 1.95 % 2.81 % — % 2.97 %
Maximum Minimum Average Interest Rates for Funds Borrowed from Loaned to Nonutility Money Pool	Three Months Ended March 31, 2020 Three Months Ended March 31, 2019 Maximum Minimum Average Maximum Minimum 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 Loaned to Loaned to Loaned to Loaned to Loaned to Loaned to the Nonutility the Nonutility the Nonutility the Nonutility the Nonutility the Nonutility Company Money Pool Money Pool Money Pool Money Pool Money Pool Money Pool AEP Texas 2.24 % 1.76 % 1.94 % 3.02 % 2.73 % 2.87 % SWEPCo 2.24 % 1.76 % 1.94 % 3.02 % 2.73 % 2.87 %
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 Three Months for Funds for Funds for Funds for Funds for Funds for Funds Ended Borrowed Borrowed Loaned Loaned Borrowed Loaned March 31, from AEP from AEP to AEP to AEP from AEP to AEP 2020 2.24 % 1.76 % 2.24 % 1.76 % 1.94 % 1.94 % 2019 3.02 % 2.73 % 3.02 % 2.73 % 2.87 % 2.86 %
Short Term Debt	March 31, 2020 December 31, 2019 Outstanding Interest Outstanding Interest Company Type of Debt Amount Rate (a) Amount Rate (a) (dollars in millions) AEP Securitized Debt for Receivables (b) $ 724.0 1.75 % $ 710.0 2.42 % AEP Commercial Paper 2,709.6 2.24 % 2,110.0 2.10 % AEP 364-Day Term Loan 1,000.0 1.53 % — — % SWEPCo Notes Payable 30.5 2.98 % 18.3 3.29 % Total Short-term Debt $ 4,464.1 $ 2,838.3 (a) Weighted-average rate. (b) Amount of securitized debt for receivables as accounted for under the “Transfers and Servicing” accounting guidance.
Comparative Accounts Receivable Information	Three Months Ended 2020 2019 (dollars in millions) Effective Interest Rates on Securitization of Accounts Receivable 1.75 % 2.71 % Net Uncollectible Accounts Receivable Written-Off $ 4.2 $ 6.4
Customer Accounts Receivable Managed Portfolio	March 31, 2020 December 31, 2019 (in millions) Accounts Receivable Retained Interest and Pledged as Collateral Less Uncollectible Accounts $ 850.7 $ 841.8 Short-term – Securitized Debt of Receivables 724.0 710.0 Delinquent Securitized Accounts Receivable 43.4 39.6 Bad Debt Reserves Related to Securitization 34.5 32.1 Unbilled Receivables Related to Securitization 219.8 266.8
Accounts Receivable and Accrued Unbilled Revenues	Company March 31, 2020 December 31, 2019 (in millions) APCo $ 121.8 $ 120.9 I&M 155.2 141.8 OPCo 338.3 330.3 PSO 93.3 101.1 SWEPCo 121.2 125.2
Fees Paid to AEP Credit for Customer Accounts Receivable Sold	Three Months Ended March 31, Company 2020 2019 (in millions) APCo $ 1.7 $ 2.2 I&M 2.8 2.8 OPCo 4.8 7.8 PSO 1.3 2.1 SWEPCo 2.1 2.6
Proceeds on Sale of Receivables to AEP Credit	Three Months Ended March 31, Company 2020 2019 (in millions) APCo $ 352.6 $ 374.4 I&M 471.4 478.6 OPCo 570.3 636.8 PSO 294.9 324.5 SWEPCo 365.6 371.9

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	3 Months Ended
	Mar. 31, 2020
Disaggregated Revenues from Contracts with Customers	Three Months Ended March 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 $ 915.1 $ 521.3 $ — $ — $ — $ — $ 1,436.4 Commercial Revenues 489.4 276.9 — — — — 766.3 Industrial Revenues 518.2 97.8 — — — (0.2 ) 615.8 Other Retail Revenues 39.9 11.8 — — — — 51.7 Total Retail Revenues 1,962.6 907.8 — — — (0.2 ) 2,870.2 Wholesale and Competitive Retail Revenues: Generation Revenues 140.4 — — 44.1 — — 184.5 Transmission Revenues (a) 79.9 114.1 309.8 — — (263.0 ) 240.8 Renewable Generation Revenues (c) — — — 17.2 — (0.6 ) 16.6 Retail, Trading and Marketing Revenues (b) — — — 358.7 (6.0 ) (29.4 ) 323.3 Total Wholesale and Competitive Retail Revenues 220.3 114.1 309.8 420.0 (6.0 ) (293.0 ) 765.2 Other Revenues from Contracts with Customers (c) 43.6 36.4 3.7 0.3 28.1 (40.6 ) 71.5 Total Revenues from Contracts with Customers 2,226.5 1,058.3 313.5 420.3 22.1 (333.8 ) 3,706.9 Other Revenues: Alternative Revenues (c) 0.2 19.3 (3.3 ) — — 4.5 20.7 Other Revenues (c) — 29.3 — 18.3 (2.2 ) (25.5 ) 19.9 Total Other Revenues 0.2 48.6 (3.3 ) 18.3 (2.2 ) (21.0 ) 40.6 Total Revenues $ 2,226.7 $ 1,106.9 $ 310.2 $ 438.6 $ 19.9 $ (354.8 ) $ 3,747.5 (a) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $239 million . The remaining affiliated amounts were immaterial. (b) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $35 million . The remaining affiliated amounts were immaterial. (c) Amounts include affiliated and nonaffiliated revenues. Three Months Ended March 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 $ 982.4 $ 586.1 $ — $ — $ — $ — $ 1,568.5 Commercial Revenues 511.2 310.9 — — — — 822.1 Industrial Revenues 532.1 123.9 — — — 1.8 657.8 Other Retail Revenues 43.3 11.1 — — — — 54.4 Total Retail Revenues 2,069.0 1,032.0 — — — 1.8 3,102.8 Wholesale and Competitive Retail Revenues: Generation Revenues 224.7 — — 108.8 — (38.8 ) 294.7 Transmission Revenues (a) 73.5 99.6 255.1 — — (219.4 ) 208.8 Renewable Generation Revenues (c) — — — 7.8 — — 7.8 Retail, Trading and Marketing Revenues (b) — — — 353.7 — — 353.7 Total Wholesale and Competitive Retail Revenues 298.2 99.6 255.1 470.3 — (258.2 ) 865.0 Other Revenues from Contracts with Customers (c) 39.5 46.0 3.1 2.3 23.3 (36.1 ) 78.1 Total Revenues from Contracts with Customers 2,406.7 1,177.6 258.2 472.6 23.3 (292.5 ) 4,045.9 Other Revenues: Alternative Revenues (c) (3.4 ) 5.0 (1.8 ) — — — (0.2 ) Other Revenues (c) — 39.4 — 9.2 2.2 (39.7 ) 11.1 Total Other Revenues (3.4 ) 44.4 (1.8 ) 9.2 2.2 (39.7 ) 10.9 Total Revenues $ 2,403.3 $ 1,222.0 $ 256.4 $ 481.8 $ 25.5 $ (332.2 ) $ 4,056.8 (a) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $198 million . The remaining affiliated amounts were immaterial. (b) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $37 million . The remaining affiliated amounts were immaterial. (c) Amounts include affiliated and nonaffiliated revenues. Three Months Ended March 31, 2020 AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Retail Revenues: Residential Revenues $ 132.9 $ — $ 357.5 $ 201.3 $ 388.4 $ 128.5 $ 131.6 Commercial Revenues 112.8 — 132.3 122.2 164.0 76.1 105.6 Industrial Revenues 35.2 — 141.1 137.8 62.7 61.3 79.8 Other Retail Revenues 8.4 — 17.9 1.8 3.4 16.6 2.0 Total Retail Revenues 289.3 — 648.8 463.1 618.5 282.5 319.0 Wholesale Revenues: Generation Revenues (a) — — 54.1 78.4 — 1.9 34.1 Transmission Revenues (b) 96.9 298.2 30.4 7.4 17.1 7.8 25.4 Total Wholesale Revenues 96.9 298.2 84.5 85.8 17.1 9.7 59.5 Other Revenues from Contracts with Customers (c) 7.9 3.4 17.2 21.0 28.6 4.7 5.8 Total Revenues from Contracts with Customers 394.1 301.6 750.5 569.9 664.2 296.9 384.3 Other Revenues: Alternative Revenues (d) (0.7 ) (6.0 ) (1.1 ) 0.4 20.0 0.4 1.6 Other Revenues (d) 30.2 — — — 6.1 — — Total Other Revenues 29.5 (6.0 ) (1.1 ) 0.4 26.1 0.4 1.6 Total Revenues $ 423.6 $ 295.6 $ 749.4 $ 570.3 $ 690.3 $ 297.3 $ 385.9 (a) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $33 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 $235 million . The remaining affiliated amounts were immaterial. (c) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $16 million primarily relating to the barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial. (d) Amounts include affiliated and nonaffiliated revenues. Three Months Ended March 31, 2019 AEP Texas AEPTCo APCo I&M OPCo PSO SWEPCo (in millions) Retail Revenues: Residential Revenues $ 120.9 $ — $ 372.5 $ 218.4 $ 471.6 $ 140.0 $ 140.1 Commercial Revenues 97.9 — 142.2 121.3 210.5 80.8 113.7 Industrial Revenues 33.0 — 147.5 138.4 89.7 71.0 81.2 Other Retail Revenues 7.3 — 19.6 1.8 3.4 18.0 2.2 Total Retail Revenues 259.1 — 681.8 479.9 775.2 309.8 337.2 Wholesale Revenues: Generation Revenues (a) — — 67.5 111.9 — 8.6 57.2 Transmission Revenues (b) 85.8 242.1 25.7 6.3 13.9 9.8 24.2 Total Wholesale Revenues 85.8 242.1 93.2 118.2 13.9 18.4 81.4 Other Revenues from Contracts with Customers (c) 6.9 3.1 13.4 21.0 39.0 5.8 7.8 Total Revenues from Contracts with Customers 351.8 245.2 788.4 619.1 828.1 334.0 426.4 Other Revenues: Alternative Revenues (d) (0.9 ) (1.7 ) 4.4 (4.8 ) 3.6 (1.2 ) (5.3 ) Other Revenues (d) 39.8 — — — 5.1 — — Total Other Revenues 38.9 (1.7 ) 4.4 (4.8 ) 8.7 (1.2 ) (5.3 ) Total Revenues $ 390.7 $ 243.5 $ 792.8 $ 614.3 $ 836.8 $ 332.8 $ 421.1 (a) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $35 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 $195 million . The remaining affiliated amounts were immaterial. (c) Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $15 million primarily relating to the barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial. (d) Amounts include affiliated and nonaffiliated revenues.
Fixed Performance Obligations	Company 2020 2021-2022 2023-2024 After 2024 Total (in millions) AEP $ 732.4 $ 171.1 $ 160.6 $ 223.4 $ 1,287.5 AEP Texas 290.3 — — — 290.3 AEPTCo 821.5 — — — 821.5 APCo 118.6 32.3 24.4 11.6 186.9 I&M 22.2 8.8 8.8 4.4 44.2 OPCo 43.2 — — — 43.2 PSO 10.8 — — — 10.8 SWEPCo 29.6 — — — 29.6
Affiliated Accounts Receivable Contracts with Customers	Company March 31, 2020 December 31, 2019 (in millions) AEPTCo $ 80.6 $ 65.9 APCo 56.3 47.3 I&M 37.4 37.1 OPCo 39.3 33.9 PSO 6.2 9.7 SWEPCo 11.0 17.6

Significant Accounting Matter_3

Significant Accounting Matters (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Amounts Attributable to AEP Common Shareholders
Earnings Attributable to Common Shareholders	$ 495.2	$ 572.8
Weighted Average Number of Basic AEP Common Shares Outstanding	494,596,869	493,309,076
Total Basic Earnings Per Share Attributable to AEP Common Shareholders	$ 1	$ 1.16
Weighted Average Dilutive Effect of:
Weighted Average Number of Diluted AEP Common Shares Outstanding	496,608,918	494,484,144
Total Diluted Earnings Per Share Attributable to AEP Common Shareholders	$ 1	$ 1.16
Organization and Summary of Significant Accounting Policies (Textuals)
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	697,000	0
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents	$ 1,554.6		$ 246.8
Restricted Cash	116.2		185.8
Total Cash, Cash Equivalents and Restricted Cash	1,670.8	$ 363.1	432.6	$ 444.1
AEP Texas Inc. [Member]
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents	0.1		3.1
Restricted Cash	100.1		154.7
Total Cash, Cash Equivalents and Restricted Cash	100.2	100.7	157.8	159.8
AEP Transmission Co [Member]
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents	0	0	0	0
Appalachian Power Co [Member]
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents	2.8		3.3
Restricted Cash	15.7		23.5
Total Cash, Cash Equivalents and Restricted Cash	18.5	21.2	26.8	29.8
Indiana Michigan Power Co [Member]
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents	1.8	1.7	2	2.4
Ohio Power Co [Member]
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents	3.1		3.7
Total Cash, Cash Equivalents and Restricted Cash	3.1	19.8	3.7	32.5
Public Service Co Of Oklahoma [Member]
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents	1.1	1.5	1.5	2
Southwestern Electric Power Co [Member]
Amounts Attributable to AEP Common Shareholders
Earnings Attributable to Common Shareholders	15.1	27.8
Cash, Cash Equivalents and Restricted Cash
Cash and Cash Equivalents	$ 1.4	$ 22.1	$ 1.6	$ 24.5
Restricted Stock Units and Performance Share Units [Member]
Weighted Average Dilutive Effect of:
Weighted Average Dilutive Effect of Shares	2,000,000	1,200,000
Dilutive Securities, Effect on Basic Earnings Per Share	$ 0	$ 0

Comprehensive Income (Details)

Comprehensive Income (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020		Mar. 31, 2019
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		$ (147.7)		$ (120.4)
Change in Fair Value Recognized in AOCI		(108)		(38.8)
Commodity
Generation & Marketing Revenues		3,747.5		4,056.8
Interest Rate
Interest Expense		292.1		255.8
Amortization Of Pension And Other Postretirement Benefit Plans
Reclassification from AOCI, before Income Tax (Expense) Benefit		49.6		10.7
Income Tax (Expense) Benefit		46.5		44.5
Reclassification from AOCI, Net of Income Tax (Expense) Benefit		39.2		8.5
Net Current Period Other Comprehensive Income (Loss)		(68.8)		(30.3)
Ending Balance in AOCI		(216.5)		(150.7)
Pension and OPEB [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(32.7)		(84.8)
Change in Fair Value Recognized in AOCI		0		0
Amortization Of Pension And Other Postretirement Benefit Plans
Reclassification from AOCI, before Income Tax (Expense) Benefit		(2.3)		(1.8)
Reclassification from AOCI, Net of Income Tax (Expense) Benefit		(1.8)		(1.4)
Net Current Period Other Comprehensive Income (Loss)		(1.8)		(1.4)
Ending Balance in AOCI		(34.5)		(86.2)
Accumulated Other Comprehensive Income [Member]
Amortization Of Pension And Other Postretirement Benefit Plans
Net Current Period Other Comprehensive Income (Loss)		(68.8)		(30.3)
Commodity [Member] | Cash Flow Hedges [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(103.5)		(23)
Change in Fair Value Recognized in AOCI		(65.3)		(38.8)
Amortization Of Pension And Other Postretirement Benefit Plans
Reclassification from AOCI, before Income Tax (Expense) Benefit		51		12.3
Reclassification from AOCI, Net of Income Tax (Expense) Benefit		40.3		9.7
Net Current Period Other Comprehensive Income (Loss)		(25)		(29.1)
Ending Balance in AOCI		(128.5)		(52.1)
Interest Rate [Member] | Cash Flow Hedges [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(11.5)		(12.6)
Change in Fair Value Recognized in AOCI		(42.7)	[1]	0
Amortization Of Pension And Other Postretirement Benefit Plans
Reclassification from AOCI, before Income Tax (Expense) Benefit		0.9		0.2
Reclassification from AOCI, Net of Income Tax (Expense) Benefit		0.7		0.2
Net Current Period Other Comprehensive Income (Loss)		(42)		0.2
Ending Balance in AOCI		(53.5)		(12.4)
Generation and Marketing Revenues [Member]
Commodity
Generation & Marketing Revenues		408.4		439.7
Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale		795.7		861.8
Reclassifications from Accumulated Other Comprehensive Income [Member]
Interest Rate
Interest Expense	[2]	0.9		0.2
Amortization Of Pension And Other Postretirement Benefit Plans
Amortization of Prior Service Cost (Credit)		(4.9)		(4.8)
Amortization of Actuarial (Gains) Losses		2.6		3
Income Tax (Expense) Benefit		10.4		2.2
Reclassifications from Accumulated Other Comprehensive Income [Member] | Pension and OPEB [Member]
Interest Rate
Interest Expense	[2]	0		0
Amortization Of Pension And Other Postretirement Benefit Plans
Amortization of Prior Service Cost (Credit)		(4.9)		(4.8)
Amortization of Actuarial (Gains) Losses		2.6		3
Income Tax (Expense) Benefit		(0.5)		(0.4)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Commodity [Member] | Cash Flow Hedges [Member]
Interest Rate
Interest Expense	[2]	0		0
Amortization Of Pension And Other Postretirement Benefit Plans
Amortization of Prior Service Cost (Credit)		0		0
Amortization of Actuarial (Gains) Losses		0		0
Income Tax (Expense) Benefit		10.7		2.6
Reclassifications from Accumulated Other Comprehensive Income [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Interest Rate
Interest Expense	[2]	0.9		0.2
Amortization Of Pension And Other Postretirement Benefit Plans
Amortization of Prior Service Cost (Credit)		0		0
Amortization of Actuarial (Gains) Losses		0		0
Income Tax (Expense) Benefit		0.2		0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Generation and Marketing Revenues [Member]
Commodity
Generation & Marketing Revenues	[1]	(0.1)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Generation and Marketing Revenues [Member] | Pension and OPEB [Member]
Commodity
Generation & Marketing Revenues	[1]	0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Generation and Marketing Revenues [Member] | Commodity [Member] | Cash Flow Hedges [Member]
Commodity
Generation & Marketing Revenues	[1]	(0.1)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Generation and Marketing Revenues [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Commodity
Generation & Marketing Revenues	[1]	0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale	[2]	51.1		12.3
Reclassifications from Accumulated Other Comprehensive Income [Member] | Purchased Electricity for Resale [Member] | Pension and OPEB [Member]
Commodity
Purchased Electricity for Resale	[2]	0		0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Purchased Electricity for Resale [Member] | Commodity [Member] | Cash Flow Hedges [Member]
Commodity
Purchased Electricity for Resale	[2]	51.1		12.3
Reclassifications from Accumulated Other Comprehensive Income [Member] | Purchased Electricity for Resale [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Commodity
Purchased Electricity for Resale	[2]	0		0
Apple Blossom and Black Oak [Member] | Reclassifications from Accumulated Other Comprehensive Income [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Interest Rate
Interest Expense		5
AEP Texas Inc. [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(12.8)		(15.1)
Change in Fair Value Recognized in AOCI		0		0
Interest Rate
Interest Expense		42.5		37.4
Amortization Of Pension And Other Postretirement Benefit Plans
Reclassification from AOCI, before Income Tax (Expense) Benefit		0.4		0.4
Income Tax (Expense) Benefit		7.4		4
Reclassification from AOCI, Net of Income Tax (Expense) Benefit		0.3		0.3
Net Current Period Other Comprehensive Income (Loss)		0.3		0.3
Ending Balance in AOCI		(12.5)		(14.8)
AEP Texas Inc. [Member] | Pension and OPEB [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(9.4)		(10.7)
Change in Fair Value Recognized in AOCI		0		0
Amortization Of Pension And Other Postretirement Benefit Plans
Reclassification from AOCI, before Income Tax (Expense) Benefit		0		0
Reclassification from AOCI, Net of Income Tax (Expense) Benefit		0		0
Net Current Period Other Comprehensive Income (Loss)		0		0
Ending Balance in AOCI		(9.4)		(10.7)
AEP Texas Inc. [Member] | Accumulated Other Comprehensive Income [Member]
Amortization Of Pension And Other Postretirement Benefit Plans
Net Current Period Other Comprehensive Income (Loss)		0.3		0.3
AEP Texas Inc. [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(3.4)		(4.4)
Change in Fair Value Recognized in AOCI		0		0
Amortization Of Pension And Other Postretirement Benefit Plans
Reclassification from AOCI, before Income Tax (Expense) Benefit		0.4		0.4
Reclassification from AOCI, Net of Income Tax (Expense) Benefit		0.3		0.3
Net Current Period Other Comprehensive Income (Loss)		0.3		0.3
Ending Balance in AOCI		(3.1)		(4.1)
AEP Texas Inc. [Member] | Reclassifications from Accumulated Other Comprehensive Income [Member]
Interest Rate
Interest Expense	[2]	0.4		0.4
Amortization Of Pension And Other Postretirement Benefit Plans
Income Tax (Expense) Benefit		0.1		0.1
AEP Texas Inc. [Member] | Reclassifications from Accumulated Other Comprehensive Income [Member] | Pension and OPEB [Member]
Interest Rate
Interest Expense	[2]	0		0
Amortization Of Pension And Other Postretirement Benefit Plans
Income Tax (Expense) Benefit		0		0
AEP Texas Inc. [Member] | Reclassifications from Accumulated Other Comprehensive Income [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Interest Rate
Interest Expense	[2]	0.4		0.4
Amortization Of Pension And Other Postretirement Benefit Plans
Income Tax (Expense) Benefit		0.1		0.1
Appalachian Power Co [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		5		(5)
Change in Fair Value Recognized in AOCI		(3.9)		0
Interest Rate
Interest Expense		53.1		49.3
Amortization Of Pension And Other Postretirement Benefit Plans
Reclassification from AOCI, before Income Tax (Expense) Benefit		(1.6)		(1.1)
Income Tax (Expense) Benefit		10.4		(24.1)
Reclassification from AOCI, Net of Income Tax (Expense) Benefit		(1.2)		(0.8)
Net Current Period Other Comprehensive Income (Loss)		(5.1)		(0.8)
Ending Balance in AOCI		(0.1)		(5.8)
Appalachian Power Co [Member] | Pension and OPEB [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		4.1		(6.8)
Change in Fair Value Recognized in AOCI		0		0
Amortization Of Pension And Other Postretirement Benefit Plans
Reclassification from AOCI, before Income Tax (Expense) Benefit		(1.2)		(0.8)
Reclassification from AOCI, Net of Income Tax (Expense) Benefit		(0.9)		(0.6)
Net Current Period Other Comprehensive Income (Loss)		(0.9)		(0.6)
Ending Balance in AOCI		3.2		(7.4)
Appalachian Power Co [Member] | Accumulated Other Comprehensive Income [Member]
Amortization Of Pension And Other Postretirement Benefit Plans
Net Current Period Other Comprehensive Income (Loss)		(5.1)		(0.8)
Appalachian Power Co [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		0.9		1.8
Change in Fair Value Recognized in AOCI		(3.9)		0
Amortization Of Pension And Other Postretirement Benefit Plans
Reclassification from AOCI, before Income Tax (Expense) Benefit		(0.4)		(0.3)
Reclassification from AOCI, Net of Income Tax (Expense) Benefit		(0.3)		(0.2)
Net Current Period Other Comprehensive Income (Loss)		(4.2)		(0.2)
Ending Balance in AOCI		(3.3)		1.6
Appalachian Power Co [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale		122.6		110.6
Appalachian Power Co [Member] | Reclassifications from Accumulated Other Comprehensive Income [Member]
Interest Rate
Interest Expense	[2]	(0.4)		(0.3)
Amortization Of Pension And Other Postretirement Benefit Plans
Amortization of Prior Service Cost (Credit)		(1.3)		(1.3)
Amortization of Actuarial (Gains) Losses		0.1		0.5
Income Tax (Expense) Benefit		(0.4)		(0.3)
Appalachian Power Co [Member] | Reclassifications from Accumulated Other Comprehensive Income [Member] | Pension and OPEB [Member]
Interest Rate
Interest Expense	[2]	0		0
Amortization Of Pension And Other Postretirement Benefit Plans
Amortization of Prior Service Cost (Credit)		(1.3)		(1.3)
Amortization of Actuarial (Gains) Losses		0.1		0.5
Income Tax (Expense) Benefit		(0.3)		(0.2)
Appalachian Power Co [Member] | Reclassifications from Accumulated Other Comprehensive Income [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Interest Rate
Interest Expense	[2]	(0.4)		(0.3)
Amortization Of Pension And Other Postretirement Benefit Plans
Amortization of Prior Service Cost (Credit)		0		0
Amortization of Actuarial (Gains) Losses		0		0
Income Tax (Expense) Benefit		(0.1)		(0.1)
Indiana Michigan Power Co [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(11.6)		(13.8)
Change in Fair Value Recognized in AOCI		0		0
Interest Rate
Interest Expense		30.7		28.9
Amortization Of Pension And Other Postretirement Benefit Plans
Reclassification from AOCI, before Income Tax (Expense) Benefit		0.5		0.5
Income Tax (Expense) Benefit		0.4		(2.7)
Reclassification from AOCI, Net of Income Tax (Expense) Benefit		0.4		0.4
Net Current Period Other Comprehensive Income (Loss)		0.4		0.4
Ending Balance in AOCI		(11.2)		(13.4)
Indiana Michigan Power Co [Member] | Pension and OPEB [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(1.7)		(2.3)
Change in Fair Value Recognized in AOCI		0		0
Amortization Of Pension And Other Postretirement Benefit Plans
Reclassification from AOCI, before Income Tax (Expense) Benefit		0		0
Reclassification from AOCI, Net of Income Tax (Expense) Benefit		0		0
Net Current Period Other Comprehensive Income (Loss)		0		0
Ending Balance in AOCI		(1.7)		(2.3)
Indiana Michigan Power Co [Member] | Accumulated Other Comprehensive Income [Member]
Amortization Of Pension And Other Postretirement Benefit Plans
Net Current Period Other Comprehensive Income (Loss)		0.4		0.4
Indiana Michigan Power Co [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(9.9)		(11.5)
Change in Fair Value Recognized in AOCI		0		0
Amortization Of Pension And Other Postretirement Benefit Plans
Reclassification from AOCI, before Income Tax (Expense) Benefit		0.5		0.5
Reclassification from AOCI, Net of Income Tax (Expense) Benefit		0.4		0.4
Net Current Period Other Comprehensive Income (Loss)		0.4		0.4
Ending Balance in AOCI		(9.5)		(11.1)
Indiana Michigan Power Co [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale		50.1		69.6
Indiana Michigan Power Co [Member] | Reclassifications from Accumulated Other Comprehensive Income [Member]
Interest Rate
Interest Expense	[2]	0.5		0.5
Amortization Of Pension And Other Postretirement Benefit Plans
Amortization of Prior Service Cost (Credit)		(0.2)		(0.2)
Amortization of Actuarial (Gains) Losses		0.2		0.2
Income Tax (Expense) Benefit		0.1		0.1
Indiana Michigan Power Co [Member] | Reclassifications from Accumulated Other Comprehensive Income [Member] | Pension and OPEB [Member]
Interest Rate
Interest Expense	[2]	0		0
Amortization Of Pension And Other Postretirement Benefit Plans
Amortization of Prior Service Cost (Credit)		(0.2)		(0.2)
Amortization of Actuarial (Gains) Losses		0.2		0.2
Income Tax (Expense) Benefit		0		0
Indiana Michigan Power Co [Member] | Reclassifications from Accumulated Other Comprehensive Income [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Interest Rate
Interest Expense	[2]	0.5		0.5
Amortization Of Pension And Other Postretirement Benefit Plans
Amortization of Prior Service Cost (Credit)		0		0
Amortization of Actuarial (Gains) Losses		0		0
Income Tax (Expense) Benefit		0.1		0.1
Ohio Power Co [Member]
Interest Rate
Interest Expense		28.9		24.6
Amortization Of Pension And Other Postretirement Benefit Plans
Income Tax (Expense) Benefit		9.7		19.8
Net Current Period Other Comprehensive Income (Loss)				(0.3)
Ohio Power Co [Member] | Accumulated Other Comprehensive Income [Member]
Amortization Of Pension And Other Postretirement Benefit Plans
Net Current Period Other Comprehensive Income (Loss)				(0.3)
Ohio Power Co [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		0		1
Change in Fair Value Recognized in AOCI		0		0
Amortization Of Pension And Other Postretirement Benefit Plans
Reclassification from AOCI, before Income Tax (Expense) Benefit		0		(0.4)
Reclassification from AOCI, Net of Income Tax (Expense) Benefit		0		(0.3)
Net Current Period Other Comprehensive Income (Loss)		0		(0.3)
Ending Balance in AOCI		0		0.7
Ohio Power Co [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale		149.1		174.2
Ohio Power Co [Member] | Reclassifications from Accumulated Other Comprehensive Income [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Interest Rate
Interest Expense	[2]	0		(0.4)
Amortization Of Pension And Other Postretirement Benefit Plans
Income Tax (Expense) Benefit		0		(0.1)
Public Service Co Of Oklahoma [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		1.1
Interest Rate
Interest Expense		15.8		16.9
Amortization Of Pension And Other Postretirement Benefit Plans
Income Tax (Expense) Benefit		0.1		0
Net Current Period Other Comprehensive Income (Loss)		(0.2)		(0.2)
Ending Balance in AOCI		0.9
Public Service Co Of Oklahoma [Member] | Accumulated Other Comprehensive Income [Member]
Amortization Of Pension And Other Postretirement Benefit Plans
Net Current Period Other Comprehensive Income (Loss)		(0.2)		(0.2)
Public Service Co Of Oklahoma [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		1.1		2.1
Change in Fair Value Recognized in AOCI		0		0
Amortization Of Pension And Other Postretirement Benefit Plans
Reclassification from AOCI, before Income Tax (Expense) Benefit		(0.3)		(0.3)
Reclassification from AOCI, Net of Income Tax (Expense) Benefit		(0.2)		(0.2)
Net Current Period Other Comprehensive Income (Loss)		(0.2)		(0.2)
Ending Balance in AOCI		0.9		1.9
Public Service Co Of Oklahoma [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale		110.4		122.9
Public Service Co Of Oklahoma [Member] | Reclassifications from Accumulated Other Comprehensive Income [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Interest Rate
Interest Expense	[2]	(0.3)		(0.3)
Amortization Of Pension And Other Postretirement Benefit Plans
Income Tax (Expense) Benefit		(0.1)		(0.1)
Southwestern Electric Power Co [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(1.3)		(5.4)
Change in Fair Value Recognized in AOCI		0		0
Interest Rate
Interest Expense		30.1		29.7
Amortization Of Pension And Other Postretirement Benefit Plans
Reclassification from AOCI, before Income Tax (Expense) Benefit		0		0.1
Income Tax (Expense) Benefit		(6.2)		0.7
Reclassification from AOCI, Net of Income Tax (Expense) Benefit		0		0.1
Net Current Period Other Comprehensive Income (Loss)		0		0.1
Ending Balance in AOCI		(1.3)		(5.3)
Southwestern Electric Power Co [Member] | Pension and OPEB [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		0.5		(2.1)
Change in Fair Value Recognized in AOCI		0		0
Amortization Of Pension And Other Postretirement Benefit Plans
Reclassification from AOCI, before Income Tax (Expense) Benefit		(0.5)		(0.4)
Reclassification from AOCI, Net of Income Tax (Expense) Benefit		(0.4)		(0.3)
Net Current Period Other Comprehensive Income (Loss)		(0.4)		(0.3)
Ending Balance in AOCI		0.1		(2.4)
Southwestern Electric Power Co [Member] | Accumulated Other Comprehensive Income [Member]
Amortization Of Pension And Other Postretirement Benefit Plans
Net Current Period Other Comprehensive Income (Loss)				0.1
Southwestern Electric Power Co [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(1.8)		(3.3)
Change in Fair Value Recognized in AOCI		0		0
Amortization Of Pension And Other Postretirement Benefit Plans
Reclassification from AOCI, before Income Tax (Expense) Benefit		0.5		0.5
Reclassification from AOCI, Net of Income Tax (Expense) Benefit		0.4		0.4
Net Current Period Other Comprehensive Income (Loss)		0.4		0.4
Ending Balance in AOCI		(1.4)		(2.9)
Southwestern Electric Power Co [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale		43.1		32.6
Southwestern Electric Power Co [Member] | Reclassifications from Accumulated Other Comprehensive Income [Member]
Interest Rate
Interest Expense	[2]	0.5		0.5
Amortization Of Pension And Other Postretirement Benefit Plans
Amortization of Prior Service Cost (Credit)		(0.5)		(0.5)
Amortization of Actuarial (Gains) Losses				0.1
Income Tax (Expense) Benefit		0		0
Southwestern Electric Power Co [Member] | Reclassifications from Accumulated Other Comprehensive Income [Member] | Pension and OPEB [Member]
Interest Rate
Interest Expense	[2]	0		0
Amortization Of Pension And Other Postretirement Benefit Plans
Amortization of Prior Service Cost (Credit)		(0.5)		(0.5)
Amortization of Actuarial (Gains) Losses				0.1
Income Tax (Expense) Benefit		(0.1)		(0.1)
Southwestern Electric Power Co [Member] | Reclassifications from Accumulated Other Comprehensive Income [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Interest Rate
Interest Expense	[2]	0.5		0.5
Amortization Of Pension And Other Postretirement Benefit Plans
Amortization of Prior Service Cost (Credit)		0		0
Amortization of Actuarial (Gains) Losses				0
Income Tax (Expense) Benefit		$ 0.1		$ 0.1
[1]	(a) The change in fair value includes $5 million
[2]	(b)

Rate Matters Regulated Operatio

Rate Matters Regulated Operations (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Dec. 31, 2019
Public Utilities, General Disclosures [Line Items]
Gross Investment		$ 22,853.7	$ 22,762.4
Accumulated Depreciation		19,368.1	19,007.6
Net Investment		61,048.9	60,138.1
Materials and Supplies		645	640.7
Regulatory Assets, Noncurrent		3,197.4	3,158.8
AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Gross Investment		351.6	351.7
Accumulated Depreciation		1,800.1	1,758.1
Net Investment		9,055.4	8,845.1
Materials and Supplies		63.8	56.7
Regulatory Assets, Noncurrent		272.2	280.6
AEP Transmission Co [Member]
Public Utilities, General Disclosures [Line Items]
Accumulated Depreciation		445.8	402.3
Net Investment		9,775.4	9,490.9
Materials and Supplies		13.4	13.8
Regulatory Assets, Noncurrent		2.5	4.2
Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Gross Investment		6,602.1	6,563.7
Accumulated Depreciation		4,497	4,432.3
Net Investment		11,156.9	11,081.9
Materials and Supplies		100.4	105.2
Regulatory Assets, Noncurrent		464	457.2
Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Gross Investment		5,114	5,099.7
Accumulated Depreciation		3,356.3	3,294.3
Net Investment		6,917.5	6,899.7
Materials and Supplies		171.1	171.3
Regulatory Assets, Noncurrent		459	482.1
Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Accumulated Depreciation		2,292.8	2,263
Net Investment		7,034.4	6,907
Materials and Supplies		58.3	52.3
Regulatory Assets, Noncurrent		396.4	351.8
Public Service Co Of Oklahoma [Member]
Public Utilities, General Disclosures [Line Items]
Gross Investment		1,577.2	1,574.6
Accumulated Depreciation		1,615.8	1,580.1
Net Investment		4,140.4	4,103.3
Materials and Supplies		47.9	46.8
Regulatory Assets, Noncurrent		378.4	375.2
Public Service Co Of Oklahoma [Member] | Oklaunion Generating Station [Member] | Generating Units Probable of Abandonment [Member]
Public Utilities, General Disclosures [Line Items]
Gross Investment		106.8
Accumulated Depreciation		92.6
Net Investment		14.2
Accelerated Depreciation Regulatory Asset	[1]	33
Materials and Supplies		3.3
Cost of Removal Regulatory Liability		$ 5.2
Expected Retirement Date		2020
Remaining Recovery Period		27 years
Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Gross Investment		$ 4,703	4,691.4
Accumulated Depreciation		2,918.7	2,873.7
Net Investment		7,146.6	7,095.2
Materials and Supplies		93.8	94
Regulatory Assets, Noncurrent		236.6	222.4
Southwestern Electric Power Co [Member] | Dolet Hills Power Station [Member] | Generating Units Probable of Abandonment [Member]
Public Utilities, General Disclosures [Line Items]
Gross Investment		341.4
Accumulated Depreciation		205
Net Investment		136.4
Accelerated Depreciation Regulatory Asset	[2]	9.1
Materials and Supplies		5.8
Cost of Removal Regulatory Liability		$ 23.7
Expected Retirement Date		2021
Remaining Recovery Period		27 years
Percent of Fuel Supply Provided by DHLC		100.00%
Asset Retirement Obligation, Revision of Estimate		$ 21
Share of Net Investment in Dolet Hills Power Station		151
Dolet Hills Lignite Company Unbilled Fixed Costs		124
Oxbow Unbilled Fixed Costs		26
Regulatory Assets Pending Final Regulatory Approval [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	[3]	162	181.7
Regulatory Assets Pending Final Regulatory Approval [Member] | Virginia Jurisdictional AMR Meters [Member]
Public Utilities, General Disclosures [Line Items]
Net Investment		52	51
Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		5.3	30.8
Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	[3]	25.9	30.6
Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member] | Virginia Jurisdictional AMR Meters [Member]
Public Utilities, General Disclosures [Line Items]
Net Investment		52	51
Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		0	7.7
Regulatory Assets Pending Final Regulatory Approval [Member] | Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		0.1	0.1
Regulatory Assets Pending Final Regulatory Approval [Member] | Public Service Co Of Oklahoma [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		40.3	34.6
Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		56.1	46.3
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Plant Retirement Costs - Unrecovered Plant [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		35.2	35.2
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Oklaunion Power Station Accelerated Depreciation [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		33	27.4
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Kentucky Deferred Purchase Power Expenses [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		32.9	30.2
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Dolet Hills Power Station Accelerated Depreciation [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		9.1	0
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Other Regulatory Assets Not Yet Being Recovered [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		2.1	0.7
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member] | Plant Retirement Costs - Materials and Supplies [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		0	0.5
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Public Service Co Of Oklahoma [Member] | Oklaunion Power Station Accelerated Depreciation [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		33	27.4
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member] | Plant Retirement Costs - Unrecovered Plant, Louisiana [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		35.2	35.2
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member] | Dolet Hills Power Station Accelerated Depreciation [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		9.1	0
Regulatory Assets Currently Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member] | Other Regulatory Assets Not Yet Being Recovered [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		2.2	0.2
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Plant Retirement Costs - Asset Retirement Obligation Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		25.9	30.1
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Asset Retirement Obligation [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		7.7	7.2
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Storm-Related Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		7.3	7.2
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Vegetation Management Program [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	[4]	3.8	29.4
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Vegetation Management Program [Member] | 2019 Texas Base Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		26
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Cook Plant Study Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	[5]	0	7.6
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Other Regulatory Assets Not Yet Being Recovered [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		5	6.7
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member] | Vegetation Management Program [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	[4]	3.8	29.4
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member] | Vegetation Management Program [Member] | 2019 Texas Base Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		26
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | AEP Texas Inc. [Member] | Other Regulatory Assets Not Yet Being Recovered [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		1.5	1.4
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Appalachian Power Co [Member] | Plant Retirement Costs - Asset Retirement Obligation Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		25.9	30.1
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member] | Cook Plant Study Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent	[5]	0	7.6
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Indiana Michigan Power Co [Member] | Other Regulatory Assets Not Yet Being Recovered [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		0	0.1
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Ohio Power Co [Member] | Other Regulatory Assets Not Yet Being Recovered [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		0.1	0.1
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Public Service Co Of Oklahoma [Member] | Storm-Related Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		7.3	7.2
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member] | Asset Retirement Obligation - Louisiana [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		7.7	7.2
Regulatory Assets Currently Not Earning Return [Member] | Regulatory Assets Pending Final Regulatory Approval [Member] | Southwestern Electric Power Co [Member] | Other Regulatory Assets Not Yet Being Recovered [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets, Noncurrent		$ 1.9	$ 3.7
[1]	In October 2018, PSO changed depreciation rates to utilize the 2020 end-of-life and defer depreciation expense to a regulatory asset for the amount in excess of the previously OCC-approved depreciation rates for Oklaunion Power Station.
[2]	In January 2020, SWEPCo changed depreciation rates to utilize the 2026 end-of-life and defer depreciation expense to a regulatory asset for the amount in excess of the previously APSC-approved depreciation rates for Dolet Hills Power Station. In March 2020, SWEPCo changed depreciation rates again to utilize the accelerated 2021 end-of-life.
[3]	APCo is currently in the process of retiring and replacing its Virginia jurisdictional Automated Meter Reading (AMR) meters with AMI meters. As of March 31, 2020 and December 31, 2019 , APCo has approximately $52 million and $51 million , respectively, of Virginia jurisdictional AMR meters recorded in Total Property, Plant and Equipment - Net on its balance sheets. APCo is pursuing full recovery of these assets through its Virginia depreciation rates. See “2017-2019 Virginia Triennial Review” section below for additional information.
[4]	In April 2020, $26 million of deferred expenses were approved for recovery. See “2019 Texas Base Rate Case” section below for additional information.
[5]	Approved for recovery in the first quarter of 2020 in the Indiana Base Rate Case.

Rate Matters East Companies (De

Rate Matters East Companies (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net	$ 61,048.9	$ 60,138.1
AEP Transmission Co [Member]
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net	9,775.4	9,490.9
Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net	11,156.9	11,081.9
Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net	6,917.5	6,899.7
Ohio Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net	$ 7,034.4	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	9.42%
2019 Indiana Base Rate Case [Member] | Indiana Michigan Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Amount of Increase Related to Annual Depreciation Rates	$ 78
Requested Annual Increase	$ 172
Requested Return on Equity	10.50%
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	$ 77
Approved Return on Common Equity	9.70%
Initial Phased in Annual Increase	$ 44
Impact on Pretax Earnings due to Loss of Significant Contract	20
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
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
Virginia Jurisdictional AMR Meters [Member] | 2017-2019 Virginia Triennial Review [Member] | Appalachian Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Property, Plant and Equipment, Net	$ 52	$ 51

Rate Matters West Companies (De

Rate Matters West Companies (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	May 06, 2020	Mar. 31, 2020	Dec. 31, 2019
Public Utilities, General Disclosures [Line Items]
Construction Work in Progress		$ 4,511.5	$ 4,319.8
AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Construction Work in Progress		747	763.9
Public Service Co Of Oklahoma [Member]
Public Utilities, General Disclosures [Line Items]
Construction Work in Progress		144.9	133.4
Southwestern Electric Power Co [Member]
Public Utilities, General Disclosures [Line Items]
Construction Work in Progress		232.7	$ 216.9
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
Other Asset Impairment Charges		33
2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member] | Rate Case Expense [Member]
Public Utilities, General Disclosures [Line Items]
Write-off of Regulatory Expense		4
2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member] | Amount of 2019 Investments [Member]
Public Utilities, General Disclosures [Line Items]
Other Asset Impairment Charges		$ 10
ETT Interim Transmission Rates [Member]
Public Utilities, General Disclosures [Line Items]
Parent Ownership Interest In ETT		50.00%
AEP Share Of ETT Cumulative Revenues Subject To Review		$ 1,100
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		$ 1,500
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%
Requested Net Increase in Texas Annual Revenues		$ 69
Approved Net Increase in Texas Annual Revenues		$ 50
Approved Return on Common Equity		9.60%
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
Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Approved Annual Revenue Decrease	$ 40
Refund for Excess ADIT Associated with Certain Depreciable Property	$ 275
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%
Subsequent Event [Member] | 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
Subsequent Event [Member] | 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
Capitalized Vegetation Management Expenses [Member] | Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Approved Item in Commission Order	26
Excess ADIT and Excess Federal Income Taxes to Distribution Customers [Member] | Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Item to be Refunded in Commission Order	77
Excess ADIT and Excess Federal Income Taxes to Transmission Customers [Member] | Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Item to be Refunded in Commission Order	31
Previously Collected Rates Subject to Reconciliation [Member] | 2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Provision for Refund		$ 30
Previously Collected Rates Subject to Reconciliation [Member] | Subsequent Event [Member] | 2019 Texas Base Rate Case [Member] | AEP Texas Inc. [Member]
Public Utilities, General Disclosures [Line Items]
Item to be Refunded in Commission Order	$ 30

Commitments, Guarantees and C_3

Commitments, Guarantees and Contingencies (Details) - USD ($) $ in Millions		1 Months Ended
		Jul. 25, 2019	Mar. 31, 2020
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements			$ 48.5
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Payments for Environmental Liabilities		$ 7.5
AEP Texas Inc. [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements			11.6
Appalachian Power Co [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements			6.6
Indiana Michigan Power Co [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements			4.3
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Payments for Environmental Liabilities		$ 7.5
Ohio Power Co [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements			7.6
Public Service Co Of Oklahoma [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements			4.4
Southwestern Electric Power Co [Member]
Maximum Potential Loss [Abstract]
Max Potential Loss on Master Lease Agreements			4.9
Rockport Lease [Member]
Present Value of Future Minimum Lease Payments, Sale Leaseback Transactions, Fiscal Year Maturity [Abstract]
Minimum Lease Payments, Sale Leaseback Transactions, Next Twelve Months	[1]		147.8
Minimum Lease Payments, Sale Leaseback Transactions, within Two Years	[1]		147.8
Minimum Lease Payments, Sale Leaseback Transactions, within Three Years	[1]		147.5
Minimum Lease Payments, Sale Leaseback Transactions	[1]		443.1
Rockport Lease [Member] | Indiana Michigan Power Co [Member]
Present Value of Future Minimum Lease Payments, Sale Leaseback Transactions, Fiscal Year Maturity [Abstract]
Minimum Lease Payments, Sale Leaseback Transactions, Next Twelve Months			73.9
Minimum Lease Payments, Sale Leaseback Transactions, within Two Years			73.9
Minimum Lease Payments, Sale Leaseback Transactions, within Three Years			73.7
Minimum Lease Payments, Sale Leaseback Transactions			221.5
Boat and Barge Leases [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Maximum Potential Lease Payments, AEPRO Barge and Boat Leases			53
Guarantor Obligations, Current Carrying Value			4
Guarantee Obligations Current Carrying Value Other Liabilities Current			1
Guarantee Obligations Current Carrying Value Other Liabilities Noncurrent			3
Letters of Credit [Member]
Maximum Future Payments for Letters of Credit [Abstract]
Maximum Future Payments for Letters of Credit Issued Under the Uncommitted Facility			241.2
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Letters of Credit Limit			1,200
Uncommitted Facility			405
Letters of Credit [Member] | AEP Texas Inc. [Member]
Maximum Future Payments for Letters of Credit [Abstract]
Maximum Future Payments for Letters of Credit Issued Under the Uncommitted Facility			2.2
Letters of Credit [Member] | Ohio Power Co [Member]
Maximum Future Payments for Letters of Credit [Abstract]
Maximum Future Payments for Letters of Credit Issued Under the Uncommitted Facility	[2]		1
June 2022 [Member] | Letters of Credit [Member]
Commitments, Guarantees and Contingencies (Textuals) [Abstract]
Revolving Credit Facilities			$ 4,000
[1]	AEP’s future minimum lease payments include equal shares from AEGCo and I&M.
[2]	In April 2020, the maturity date was extended from April 2020 to April 2021.

Acquisitions and Impairments (D

Acquisitions and Impairments (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020USD ($)RateMW	Mar. 31, 2019USD ($)
Utilities Operating Expense, Operations	$ 602.1	$ 666
Generation And Marketing [Member] | AEP Wind Holdings LLC [Member]
Maximum Potential Amount of Future Payments Associated with Guarantee	175
Guarantor Obligations, Current Carrying Value	$ 33
Percentage of an Asset Acquired | Rate	50.00%
Wind Generation MWs | MW	724
Noncash or Part Noncash Acquisition, Value of Assets Acquired	$ 1,100
Payments to Acquire Businesses, Gross	580
Noncash or Part Noncash Acquisition, Debt Assumed	364
Guarantor Obligations, Current Carrying Value, Contingent Portion	1
Equity Method Investments [Member] | Generation And Marketing [Member] | AEP Wind Holdings LLC [Member]
Acquisition	404
Noncontrolling Interest [Member] | Generation And Marketing [Member] | AEP Wind Holdings LLC [Member]
Noncash or Part Noncash Acquisition, Other Assets Acquired	135
Indiana Michigan Power Co [Member]
Cost of Purchased Power from Affiliate	36.2	59.8
Utilities Operating Expense, Operations	144.7	140.5
Ohio Power Co [Member]
Cost of Purchased Power from Affiliate	42.4	46.1
Utilities Operating Expense, Operations	177.3	216.9
Southwestern Electric Power Co [Member]
Utilities Operating Expense, Operations	$ 92.2	$ 84.6

Benefit Plans (Details)

Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Pension Plans [Member]
Components of Net Periodic Benefit Cost
Service Cost	$ 28	$ 23.9
Interest Cost	42	51.1
Expected Return on Plan Assets	(66.2)	(74)
Amortization of Prior Service Cost (Credit)	0	0
Amortization of Net Actuarial Loss	23.4	14.4
Net Periodic Benefit Cost (Credit)	27.2	15.4
Pension Plans [Member] | AEP Texas Inc. [Member]
Components of Net Periodic Benefit Cost
Service Cost	2.6	2.1
Interest Cost	3.5	4.4
Expected Return on Plan Assets	(5.7)	(6.4)
Amortization of Prior Service Cost (Credit)	0	0
Amortization of Net Actuarial Loss	1.9	1.2
Net Periodic Benefit Cost (Credit)	2.3	1.3
Pension Plans [Member] | Appalachian Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	2.6	2.4
Interest Cost	5.1	6.3
Expected Return on Plan Assets	(8.4)	(9.4)
Amortization of Prior Service Cost (Credit)	0	0
Amortization of Net Actuarial Loss	2.8	1.8
Net Periodic Benefit Cost (Credit)	2.1	1.1
Pension Plans [Member] | Indiana Michigan Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	3.9	3.4
Interest Cost	4.9	6
Expected Return on Plan Assets	(8.3)	(9.2)
Amortization of Prior Service Cost (Credit)	0	0
Amortization of Net Actuarial Loss	2.7	1.6
Net Periodic Benefit Cost (Credit)	3.2	1.8
Pension Plans [Member] | Ohio Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	2.4	2
Interest Cost	3.9	4.7
Expected Return on Plan Assets	(6.6)	(7.3)
Amortization of Prior Service Cost (Credit)	0	0
Amortization of Net Actuarial Loss	2.1	1.3
Net Periodic Benefit Cost (Credit)	1.8	0.7
Pension Plans [Member] | Public Service Co Of Oklahoma [Member]
Components of Net Periodic Benefit Cost
Service Cost	1.8	1.6
Interest Cost	2.1	2.6
Expected Return on Plan Assets	(3.6)	(4.1)
Amortization of Prior Service Cost (Credit)	0	0
Amortization of Net Actuarial Loss	1.2	0.8
Net Periodic Benefit Cost (Credit)	1.5	0.9
Pension Plans [Member] | Southwestern Electric Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	2.5	2.1
Interest Cost	2.5	3.1
Expected Return on Plan Assets	(3.9)	(4.4)
Amortization of Prior Service Cost (Credit)	0	0
Amortization of Net Actuarial Loss	1.4	0.9
Net Periodic Benefit Cost (Credit)	2.5	1.7
Other Postretirement Benefit Plans [Member]
Components of Net Periodic Benefit Cost
Service Cost	2.5	2.4
Interest Cost	9.9	12.6
Expected Return on Plan Assets	(23.9)	(23.4)
Amortization of Prior Service Cost (Credit)	(17.4)	(17.3)
Amortization of Net Actuarial Loss	1.5	5.5
Net Periodic Benefit Cost (Credit)	(27.4)	(20.2)
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member]
Components of Net Periodic Benefit Cost
Service Cost	0.2	0.2
Interest Cost	0.8	1
Expected Return on Plan Assets	(2)	(2)
Amortization of Prior Service Cost (Credit)	(1.4)	(1.5)
Amortization of Net Actuarial Loss	0.1	0.5
Net Periodic Benefit Cost (Credit)	(2.3)	(1.8)
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	0.3	0.3
Interest Cost	1.6	2.2
Expected Return on Plan Assets	(3.6)	(3.7)
Amortization of Prior Service Cost (Credit)	(2.5)	(2.5)
Amortization of Net Actuarial Loss	0.2	0.9
Net Periodic Benefit Cost (Credit)	(4)	(2.8)
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	0.3	0.3
Interest Cost	1.2	1.5
Expected Return on Plan Assets	(2.9)	(2.8)
Amortization of Prior Service Cost (Credit)	(2.4)	(2.4)
Amortization of Net Actuarial Loss	0.2	0.7
Net Periodic Benefit Cost (Credit)	(3.6)	(2.7)
Other Postretirement Benefit Plans [Member] | Ohio Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	0.2	0.2
Interest Cost	1	1.4
Expected Return on Plan Assets	(2.6)	(2.7)
Amortization of Prior Service Cost (Credit)	(1.8)	(1.7)
Amortization of Net Actuarial Loss	0.2	0.6
Net Periodic Benefit Cost (Credit)	(3)	(2.2)
Other Postretirement Benefit Plans [Member] | Public Service Co Of Oklahoma [Member]
Components of Net Periodic Benefit Cost
Service Cost	0.2	0.2
Interest Cost	0.5	0.7
Expected Return on Plan Assets	(1.3)	(1.3)
Amortization of Prior Service Cost (Credit)	(1.1)	(1.1)
Amortization of Net Actuarial Loss	0.1	0.3
Net Periodic Benefit Cost (Credit)	(1.6)	(1.2)
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	0.2	0.2
Interest Cost	0.6	0.8
Expected Return on Plan Assets	(1.5)	(1.5)
Amortization of Prior Service Cost (Credit)	(1.3)	(1.3)
Amortization of Net Actuarial Loss	0.1	0.3
Net Periodic Benefit Cost (Credit)	$ (1.9)	$ (1.5)

Business Segments (Details)

Business Segments (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Reportable Segment Information
Revenue from Contracts with Customers		$ 3,747.5	$ 4,056.8
Sales to AEP Affiliates		0	0
Total Revenues		3,747.5	4,056.8
Interest Expense		292.1	255.8
Income Tax Expense (Benefit)		46.5	44.5
Net Income (Loss)		499.3	574.1
Balance Sheet Information
Total Property, Plant and Equipment		80,417		$ 79,145.7
Accumulated Depreciation and Amortization		19,368.1		19,007.6
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		61,048.9		60,138.1
Total Assets		77,724		75,892.3
Affiliated Long Term Debt Current		0		0
Long-term Debt Due Within One Year		2,109.7		1,598.7
Long-term Debt - Affiliated		0		0
Long-term Debt		25,783		25,126.8
Total Long-term Debt Outstanding		27,892.7		26,725.5
Vertically Integrated Utilities [Member]
Reportable Segment Information
Revenue from Contracts with Customers		2,193	2,372.3
Transmission and Distribution Utilities Revenues [Member]
Reportable Segment Information
Revenue from Contracts with Customers		1,075.2	1,179.8
Generation and Marketing Revenues [Member]
Reportable Segment Information
Revenue from Contracts with Customers		408.4	439.7
Other Revenues [Member]
Reportable Segment Information
Revenue from Contracts with Customers		70.9	65
AEP Transmission Co [Member]
Reportable Segment Information
Sales to AEP Affiliates		233.7	193.2
Total Revenues		295.6	243.5
Interest Income		0.8	0.7
Interest Expense		29.6	21.7
Income Tax Expense (Benefit)		31.8	27.6
Net Income (Loss)		117.8	104.3
Balance Sheet Information
Total Property, Plant and Equipment		10,221.2		9,893.2
Accumulated Depreciation and Amortization		445.8		402.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		9,775.4		9,490.9
Notes Receivable, Related Parties		0		0
Total Assets		10,199.9		9,890.8
Long-term Debt		3,427.8		3,427.3
Total Long-term Debt Outstanding		3,427.8		3,427.3
AEP Transmission Co [Member] | Transmission [Member]
Reportable Segment Information
Revenue from Contracts with Customers		61.3	50.3
AEP Transmission Co [Member] | Other Revenues [Member]
Reportable Segment Information
Revenue from Contracts with Customers		0.6	0
Reconciling Adjustments [Member]
Reportable Segment Information
Revenue from Contracts with Customers		0	0
Sales to AEP Affiliates		(354.8)	(332.2)
Total Revenues		(354.8)	(332.2)
Net Income (Loss)		0	0
Balance Sheet Information
Total Property, Plant and Equipment	[1]	(354.5)		(354.5)
Accumulated Depreciation and Amortization	[1]	(186.5)		(186.4)
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	[1]	(168)		(168.1)
Total Assets	[1],[2]	(3,923.8)		(3,801.3)
Affiliated Long Term Debt Current		(20)		(20)
Long-term Debt Due Within One Year		0		0
Long-term Debt - Affiliated		(39)		(39)
Long-term Debt		0		0
Total Long-term Debt Outstanding		(59)		(59)
Reconciling Adjustments [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contracts with Customers		0	0
Sales to AEP Affiliates		0	0
Total Revenues		0	0
Interest Income	[3]	(33.4)	(27.9)
Interest Expense	[3]	(33.4)	(27.9)
Income Tax Expense (Benefit)		0	0
Net Income (Loss)		0	0
Balance Sheet Information
Total Property, Plant and Equipment		0		0
Accumulated Depreciation and Amortization		0		0
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		0		0
Notes Receivable, Related Parties	[4]	(3,427.8)		(3,427.3)
Total Assets	[5]	(3,513.7)		(3,493.3)
Total Long-term Debt Outstanding	[4]	(3,465)		(3,465)
Reconciling Adjustments [Member] | AEP Transmission Co [Member] | Other Revenues [Member]
Reportable Segment Information
Revenue from Contracts with Customers		0
Vertically Integrated Utilities [Member]
Reportable Segment Information
Sales to AEP Affiliates		33.7	31
Total Revenues		2,226.7	2,403.3
Net Income (Loss)		246.3	303.6
Balance Sheet Information
Total Property, Plant and Equipment		47,764.3		47,323.7
Accumulated Depreciation and Amortization		14,821.8		14,580.4
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		32,942.5		32,743.3
Total Assets		41,020.5		41,228.8
Affiliated Long Term Debt Current		20		20
Long-term Debt Due Within One Year		1,316.3		704.7
Long-term Debt - Affiliated		39		39
Long-term Debt		11,641		12,162
Total Long-term Debt Outstanding		13,016.3		12,925.7
Vertically Integrated Utilities [Member] | Vertically Integrated Utilities [Member]
Reportable Segment Information
Revenue from Contracts with Customers		2,193	2,372.3
Transmission And Distribution Utilities [Member]
Reportable Segment Information
Sales to AEP Affiliates		31.7	42.2
Total Revenues		1,106.9	1,222
Net Income (Loss)		116.2	156.5
Balance Sheet Information
Total Property, Plant and Equipment		20,182.8		19,773.3
Accumulated Depreciation and Amortization		3,964.6		3,911.2
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		16,218.2		15,862.1
Total Assets		18,892.5		18,757.5
Affiliated Long Term Debt Current		0		0
Long-term Debt Due Within One Year		289		392.2
Long-term Debt - Affiliated		0		0
Long-term Debt		6,585.5		6,248.1
Total Long-term Debt Outstanding		6,874.5		6,640.3
Transmission And Distribution Utilities [Member] | Transmission and Distribution Utilities Revenues [Member]
Reportable Segment Information
Revenue from Contracts with Customers		1,075.2	1,179.8
AEP Transmission Holdco [Member]
Reportable Segment Information
Sales to AEP Affiliates		237.1	195.2
Total Revenues		310.2	256.4
Net Income (Loss)		141.6	125.2
Balance Sheet Information
Total Property, Plant and Equipment		10,662.9		10,334
Accumulated Depreciation and Amortization		464		418.9
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		10,198.9		9,915.1
Total Assets		11,484.8		11,143.5
Affiliated Long Term Debt Current		0		0
Long-term Debt Due Within One Year		0		0
Long-term Debt - Affiliated		0		0
Long-term Debt		3,600.3		3,593.8
Total Long-term Debt Outstanding		3,600.3		3,593.8
AEP Transmission Holdco [Member] | Transmission [Member]
Reportable Segment Information
Revenue from Contracts with Customers		73.1	61.2
Generation And Marketing [Member]
Reportable Segment Information
Sales to AEP Affiliates		30.2	42.1
Total Revenues		438.6	481.8
Net Income (Loss)		30.5	39.2
Balance Sheet Information
Total Property, Plant and Equipment		1,753.2		1,650.8
Accumulated Depreciation and Amortization		116.9		99
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		1,636.3		1,551.8
Total Assets		3,216.4		3,123.8
Affiliated Long Term Debt Current		0		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		408.4	439.7
All Other [Member]
Reportable Segment Information
Sales to AEP Affiliates	[6]	22.1	21.7
Total Revenues	[6]	19.9	25.5
Net Income (Loss)	[6]	(35.3)	(50.4)
Balance Sheet Information
Total Property, Plant and Equipment	[6]	408.3		418.4
Accumulated Depreciation and Amortization	[6]	187.3		184.5
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	[6]	221		233.9
Total Assets	[6],[7]	7,033.6		5,440
Affiliated Long Term Debt Current	[6]	0		0
Long-term Debt Due Within One Year	[6],[8]	504.4		501.8
Long-term Debt - Affiliated	[6]	0		0
Long-term Debt	[6],[8]	3,956.2		3,122.9
Total Long-term Debt Outstanding	[6]	4,460.6		3,624.7
All Other [Member] | Other Revenues [Member]
Reportable Segment Information
Revenue from Contracts with Customers	[6]	(2.2)	3.8
State Transcos [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Sales to AEP Affiliates		233.7	193.2
Total Revenues		295.6	243.5
Interest Income		0.2	0.2
Interest Expense		29.6	21.7
Income Tax Expense (Benefit)		31.8	27.6
Net Income (Loss)		117.3	104.2
Balance Sheet Information
Total Property, Plant and Equipment		10,221.2		9,893.2
Accumulated Depreciation and Amortization		445.8		402.3
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		9,775.4		9,490.9
Notes Receivable, Related Parties		0		0
Total Assets		10,150.9		9,865
Total Long-term Debt Outstanding		3,465		3,465
State Transcos [Member] | AEP Transmission Co [Member] | Transmission [Member]
Reportable Segment Information
Revenue from Contracts with Customers		61.3	50.3
State Transcos [Member] | AEP Transmission Co [Member] | Other Revenues [Member]
Reportable Segment Information
Revenue from Contracts with Customers		0.6
AEPTCo Parent [Member] | AEP Transmission Co [Member]
Reportable Segment Information
Revenue from Contracts with Customers		0	0
Sales to AEP Affiliates		0	0
Total Revenues		0	0
Interest Income		34	28.4
Interest Expense		33.4	27.9
Income Tax Expense (Benefit)		0	0
Net Income (Loss)	[9]	0.5	$ 0.1
Balance Sheet Information
Total Property, Plant and Equipment		0		0
Accumulated Depreciation and Amortization		0		0
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		0		0
Notes Receivable, Related Parties		3,427.8		3,427.3
Total Assets	[10]	3,562.7		3,519.1
Total Long-term Debt Outstanding		3,427.8		$ 3,427.3
AEPTCo Parent [Member] | AEP Transmission Co [Member] | Transmission [Member]
Reportable Segment Information
Revenue from Contracts with Customers		$ 0
[1]	Includes eliminations due to an intercompany finance lease.
[2]	Reconciling Adjustments for Total Assets primarily include elimination of intercompany advances to affiliates and intercompany accounts receivable.
[3]	Elimination of intercompany interest income/interest expense on affiliated debt arrangement.
[4]	Elimination of intercompany debt.
[5]	Primarily relates to the elimination of Notes Receivable from the State Transcos.
[6]	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.
[7]	Includes elimination of AEP Parent’s investments in wholly-owned subsidiary companies.
[8]	Amounts reflect the impact of fair value hedge accounting. See “Accounting for Fair Value Hedging Strategies” section of Note 10 for additional information.
[9]	Includes the elimination of AEPTCo Parent’s equity earnings in the State Transcos.
[10]	Includes the elimination of AEPTCo Parent’s investments in State Transcos.

Derivatives and Hedging (Detail

Derivatives and Hedging (Details) gal in Millions, MWh in Millions, MMBTU in Millions		3 Months Ended			12 Months Ended
		Mar. 31, 2020USD ($)MWhMMBTUgal		Mar. 31, 2019USD ($)	Dec. 31, 2019USD ($)MWhMMBTUgal
Cash Collateral Netting
Cash Collateral Received Netted Against Risk Management Assets		$ 0			$ 5,000,000
Cash Collateral Paid Netted Against Risk Management Liabilities		76,000,000			39,000,000
Fair Value of Derivative Instruments
Current Risk Management Assets		130,400,000			172,800,000
Long-term Risk Management Assets		323,700,000			266,600,000
Total Assets		454,100,000			439,400,000
Current Risk Management Liabilities		156,800,000			114,300,000
Long-term Risk Management Liabilities		291,900,000			261,800,000
Total Liabilities		448,700,000			376,100,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		(32,900,000)		$ (24,900,000)
Carrying Amount of Hedged Asset (Liability)	[1]	(553,400,000)			(510,800,000)
Cumulative Fair Value Hedging Adjustment in the Carrying Amount of the Hedged Asset (Liability)	[1]	(57,000,000)			(14,500,000)
Gain (Loss) on Hedging Instruments
Gain (Loss) on Fair Value Hedging Instruments	[2]	42,500,000		11,100,000
Gain (Loss) on Fair Value Portion of Long Term Debt	[2]	(42,500,000)		(11,100,000)
Collateral Triggering Events [Abstract]
Fair Value Of Derivative Liabilities Subject To Cross Default Provisions		310,400,000			267,300,000
Amount of Cash Collateral Posted		1,600,000			3,700,000
Additional Settlement Liability if Cross Default Provision is Triggered		282,900,000			246,700,000
AEP Texas Inc. [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		(1,400,000)		400,000
Appalachian Power Co [Member]
Cash Collateral Netting
Cash Collateral Paid Netted Against Risk Management Liabilities		5,000,000			1,000,000
Fair Value of Derivative Instruments
Current Risk Management Assets		18,100,000			39,400,000
Long-term Risk Management Assets		100,000			100,000
Total Assets		18,200,000
Current Risk Management Liabilities		15,000,000			1,900,000
Long-term Risk Management Liabilities		100,000			0
Total Liabilities		15,100,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		(16,000,000)		(34,000,000)
Collateral Triggering Events [Abstract]
Fair Value Of Derivative Liabilities Subject To Cross Default Provisions		2,200,000			2,300,000
Amount of Cash Collateral Posted		0			0
Additional Settlement Liability if Cross Default Provision is Triggered		200,000			400,000
Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		6,700,000			9,800,000
Long-term Risk Management Assets		100,000			100,000
Current Risk Management Liabilities		1,700,000			500,000
Long-term Risk Management Liabilities		100,000			0
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		2,600,000		7,200,000
Collateral Triggering Events [Abstract]
Fair Value Of Derivative Liabilities Subject To Cross Default Provisions		1,300,000			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		112,200,000			96,300,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		(15,000,000)		(9,100,000)
Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		6,400,000			15,800,000
Current Risk Management Liabilities		100,000			0
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		7,600,000		6,700,000
Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		2,600,000			6,400,000
Current Risk Management Liabilities		2,200,000			1,900,000
Long-term Risk Management Liabilities		2,900,000			3,100,000
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		1,300,000		4,600,000
Collateral Triggering Events [Abstract]
Fair Value Of Derivative Liabilities Subject To Cross Default Provisions		5,500,000			5,100,000
Amount of Cash Collateral Posted		0			0
Additional Settlement Liability if Cross Default Provision is Triggered		5,500,000			5,100,000
Risk Management Contracts [Member]
Fair Value of Derivative Instruments
Total Assets	[3]	379,100,000	[4]		408,800,000	[5]
Total Liabilities	[3]	266,600,000	[4]		239,000,000	[5]
Risk Management Contracts [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Total Liabilities	[3]	0
Risk Management Contracts [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[3],[6]	17,900,000			39,500,000
Total Liabilities	[3],[6]	9,800,000			1,900,000
Risk Management Contracts [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[3],[6]	6,800,000			9,900,000
Total Liabilities	[3],[6]	1,800,000			500,000
Risk Management Contracts [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Total Liabilities	[3],[6]	120,900,000			103,600,000
Risk Management Contracts [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Total Assets	[3],[6]	6,400,000			15,800,000
Total Liabilities	[3],[6]	100,000			0
Risk Management Contracts [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Total Assets	[3],[6]	2,600,000			6,400,000
Total Liabilities	[3],[6]	5,100,000			5,000,000
Commodity [Member]
Impact of Cash Flow Hedges on the Condensed Balance Sheet
AOCI Gain (Loss) Net of Tax		(128,500,000)			(103,500,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months		$ (73,200,000)			(51,700,000)
Derivatives and Hedging (Textuals) [Abstract]
Maximum Term for Exposure to Variability of Future Cash Flows		132 months
Cross Default Provisions Maximum Third Party Obligation Amount		$ 50,000,000			50,000,000
Commodity [Member] | Risk Management Contracts [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[7]	412,700,000			513,900,000
Long-term Risk Management Assets	[7]	331,600,000			290,800,000
Total Assets	[7]	744,300,000			804,700,000
Current Risk Management Liabilities	[7]	401,700,000			424,500,000
Long-term Risk Management Liabilities	[7]	305,900,000			244,500,000
Total Liabilities	[7]	707,600,000			669,000,000
Total MTM Derivative Contract Net Assets (Liabilities)	[7]	36,700,000			135,700,000
Commodity [Member] | Risk Management Contracts [Member] | AEP Texas Inc. [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[7]	0			0
Long-term Risk Management Assets	[7]	0			0
Total Assets	[7]	0			0
Current Risk Management Liabilities	[7]	1,200,000			0
Long-term Risk Management Liabilities	[7]	0			0
Total Liabilities	[7]	1,200,000			0
Total MTM Derivative Contract Net Assets (Liabilities)	[7]	(1,200,000)			0
Commodity [Member] | Risk Management Contracts [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[7]	71,100,000			124,400,000
Long-term Risk Management Assets	[7]	3,500,000			900,000
Total Assets	[7]	74,600,000			125,300,000
Current Risk Management Liabilities	[7]	68,300,000			86,200,000
Long-term Risk Management Liabilities	[7]	3,500,000			700,000
Total Liabilities	[7]	71,800,000			86,900,000
Total MTM Derivative Contract Net Assets (Liabilities)	[7]	2,800,000			38,400,000
Commodity [Member] | Risk Management Contracts [Member] | Indiana Michigan Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[7]	42,300,000			66,900,000
Long-term Risk Management Assets	[7]	2,100,000			500,000
Total Assets	[7]	44,400,000			67,400,000
Current Risk Management Liabilities	[7]	38,300,000			55,200,000
Long-term Risk Management Liabilities	[7]	2,100,000			400,000
Total Liabilities	[7]	40,400,000			55,600,000
Total MTM Derivative Contract Net Assets (Liabilities)	[7]	4,000,000			11,800,000
Commodity [Member] | Risk Management Contracts [Member] | Ohio Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[7]	0			0
Long-term Risk Management Assets	[7]	0			0
Total Assets	[7]	0			0
Current Risk Management Liabilities	[7]	9,600,000			7,300,000
Long-term Risk Management Liabilities	[7]	112,200,000			96,300,000
Total Liabilities	[7]	121,800,000			103,600,000
Total MTM Derivative Contract Net Assets (Liabilities)	[7]	(121,800,000)			(103,600,000)
Commodity [Member] | Risk Management Contracts [Member] | Public Service Co Of Oklahoma [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[7]	6,700,000			16,300,000
Long-term Risk Management Assets	[7]	0			0
Total Assets	[7]	6,700,000			16,300,000
Current Risk Management Liabilities	[7]	900,000			500,000
Long-term Risk Management Liabilities	[7]	0			0
Total Liabilities	[7]	900,000			500,000
Total MTM Derivative Contract Net Assets (Liabilities)	[7]	5,800,000			15,800,000
Commodity [Member] | Risk Management Contracts [Member] | Southwestern Electric Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[7]	2,700,000			6,500,000
Long-term Risk Management Assets	[7]	0			0
Total Assets	[7]	2,700,000			6,500,000
Current Risk Management Liabilities	[7]	2,900,000			2,000,000
Long-term Risk Management Liabilities	[7]	2,900,000			3,100,000
Total Liabilities	[7]	5,800,000			5,100,000
Total MTM Derivative Contract Net Assets (Liabilities)	[7]	(3,100,000)			1,400,000
Commodity [Member] | Hedging Contracts [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[7]	13,500,000			11,500,000
Long-term Risk Management Assets	[7]	13,500,000			11,000,000
Total Assets	[7]	27,000,000			22,500,000
Current Risk Management Liabilities	[7]	103,200,000			72,300,000
Long-term Risk Management Liabilities	[7]	82,900,000			75,700,000
Total Liabilities	[7]	186,100,000			148,000,000
Total MTM Derivative Contract Net Assets (Liabilities)	[7]	(159,100,000)			(125,500,000)
Interest Rate [Member]
Commodity:
Derivative, Notional Amount		650,000,000			625,000,000
Impact of Cash Flow Hedges on the Condensed Balance Sheet
AOCI Gain (Loss) Net of Tax		(53,500,000)			(11,500,000)
Portion Expected to be Reclassified to Net Income During the Next Twelve Months		$ (4,300,000)			(2,100,000)
Derivatives and Hedging (Textuals) [Abstract]
Maximum Term for Exposure to Variability of Future Cash Flows		129 months
Interest Rate [Member] | AEP Texas Inc. [Member]
Commodity:
Derivative, Notional Amount		$ 0			0
Impact of Cash Flow Hedges on the Condensed Balance Sheet
AOCI Gain (Loss) Net of Tax		(3,100,000)			(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		150,000,000			0
Impact of Cash Flow Hedges on the Condensed Balance Sheet
AOCI Gain (Loss) Net of Tax		(3,300,000)			900,000
Portion Expected to be Reclassified to Net Income During the Next Twelve Months		1,100,000			900,000
Interest Rate [Member] | Indiana Michigan Power Co [Member]
Commodity:
Derivative, Notional Amount		0			0
Impact of Cash Flow Hedges on the Condensed Balance Sheet
AOCI Gain (Loss) Net of Tax		(9,500,000)			(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 Condensed Balance Sheet
AOCI Gain (Loss) Net of Tax		900,000			1,100,000
Portion Expected to be Reclassified to Net Income During the Next Twelve Months		900,000			1,000,000
Interest Rate [Member] | Southwestern Electric Power Co [Member]
Commodity:
Derivative, Notional Amount		0			0
Impact of Cash Flow Hedges on the Condensed Balance Sheet
AOCI Gain (Loss) Net of Tax		(1,400,000)			(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	[7]	4,600,000			6,500,000
Long-term Risk Management Assets	[7]	52,700,000			12,600,000
Total Assets	[7]	57,300,000			19,100,000
Current Risk Management Liabilities	[7]	5,300,000			0
Long-term Risk Management Liabilities	[7]	0			0
Total Liabilities	[7]	5,300,000			0
Total MTM Derivative Contract Net Assets (Liabilities)	[7]	52,000,000			19,100,000
Interest Rate [Member] | Hedging Contracts [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[7]	300,000
Long-term Risk Management Assets	[7]	0
Total Assets	[7]	300,000
Current Risk Management Liabilities	[7]	5,300,000
Long-term Risk Management Liabilities	[7]	0
Total Liabilities	[7]	5,300,000
Total MTM Derivative Contract Net Assets (Liabilities)	[7]	(5,000,000)
Gross Amounts of Risk Management Assets/Liabilities Recognized [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets		430,800,000			531,900,000
Long-term Risk Management Assets		397,800,000			314,400,000
Total Assets		828,600,000			846,300,000
Current Risk Management Liabilities		510,200,000			496,800,000
Long-term Risk Management Liabilities		388,800,000			320,200,000
Total Liabilities		899,000,000			817,000,000
Total MTM Derivative Contract Net Assets (Liabilities)		(70,400,000)			29,300,000
Gross Amounts Offset in the Statement of Financial Position [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[8]	(300,400,000)			(359,100,000)
Long-term Risk Management Assets	[8]	(74,100,000)			(47,800,000)
Total Assets	[8]	(374,500,000)			(406,900,000)
Current Risk Management Liabilities	[8]	(353,400,000)			(382,500,000)
Long-term Risk Management Liabilities	[8]	(96,900,000)			(58,400,000)
Total Liabilities	[8]	(450,300,000)			(440,900,000)
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	75,800,000			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	[8]	0			0
Long-term Risk Management Assets	[8]	0			0
Total Assets	[8]	0			0
Current Risk Management Liabilities	[8]	(1,200,000)			0
Long-term Risk Management Liabilities	[8]	0			0
Total Liabilities	[8]	(1,200,000)			0
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	1,200,000			0
Gross Amounts Offset in the Statement of Financial Position [Member] | Appalachian Power Co [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[8]	(53,300,000)			(85,000,000)
Long-term Risk Management Assets	[8]	(3,400,000)			(800,000)
Total Assets	[8]	(56,700,000)			(85,800,000)
Current Risk Management Liabilities	[8]	(58,600,000)			(84,300,000)
Long-term Risk Management Liabilities	[8]	(3,400,000)			(700,000)
Total Liabilities	[8]	(62,000,000)			(85,000,000)
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	5,300,000			(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	[8]	(35,600,000)			(57,100,000)
Long-term Risk Management Assets	[8]	(2,000,000)			(400,000)
Total Assets	[8]	(37,600,000)			(57,500,000)
Current Risk Management Liabilities	[8]	(36,600,000)			(54,700,000)
Long-term Risk Management Liabilities	[8]	(2,000,000)			(400,000)
Total Liabilities	[8]	(38,600,000)			(55,100,000)
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	1,000,000			(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	[8]	0			0
Long-term Risk Management Assets	[8]	0			0
Total Assets	[8]	0			0
Current Risk Management Liabilities	[8]	(900,000)			0
Long-term Risk Management Liabilities	[8]	0			0
Total Liabilities	[8]	(900,000)			0
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	900,000			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	[8]	(300,000)			(500,000)
Long-term Risk Management Assets	[8]	0			0
Total Assets	[8]	(300,000)			(500,000)
Current Risk Management Liabilities	[8]	(800,000)			(500,000)
Long-term Risk Management Liabilities	[8]	0			0
Total Liabilities	[8]	(800,000)			(500,000)
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	500,000			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	[8]	(100,000)			(100,000)
Long-term Risk Management Assets	[8]	0			0
Total Assets	[8]	(100,000)			(100,000)
Current Risk Management Liabilities	[8]	(700,000)			(100,000)
Long-term Risk Management Liabilities	[8]	0			0
Total Liabilities	[8]	(700,000)			(100,000)
Total MTM Derivative Contract Net Assets (Liabilities)	[8]	600,000			0
Net Amounts of Assets/Liabilities Presented in the Statement of Financial Position [Member]
Fair Value of Derivative Instruments
Current Risk Management Assets	[9]	130,400,000			172,800,000
Long-term Risk Management Assets	[9]	323,700,000			266,600,000
Total Assets	[9]	454,100,000			439,400,000
Current Risk Management Liabilities	[9]	156,800,000			114,300,000
Long-term Risk Management Liabilities	[9]	291,900,000			261,800,000
Total Liabilities	[9]	448,700,000			376,100,000
Total MTM Derivative Contract Net Assets (Liabilities)	[9]	5,400,000			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	[9]	0			0
Long-term Risk Management Assets	[9]	0			0
Total Assets	[9]	0			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]	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	[9]	18,100,000			39,400,000
Long-term Risk Management Assets	[9]	100,000			100,000
Total Assets	[9]	18,200,000			39,500,000
Current Risk Management Liabilities	[9]	15,000,000			1,900,000
Long-term Risk Management Liabilities	[9]	100,000			0
Total Liabilities	[9]	15,100,000			1,900,000
Total MTM Derivative Contract Net Assets (Liabilities)	[9]	3,100,000			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	[9]	6,700,000			9,800,000
Long-term Risk Management Assets	[9]	100,000			100,000
Total Assets	[9]	6,800,000			9,900,000
Current Risk Management Liabilities	[9]	1,700,000			500,000
Long-term Risk Management Liabilities	[9]	100,000			0
Total Liabilities	[9]	1,800,000			500,000
Total MTM Derivative Contract Net Assets (Liabilities)	[9]	5,000,000			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	[9]	0			0
Long-term Risk Management Assets	[9]	0			0
Total Assets	[9]	0			0
Current Risk Management Liabilities	[9]	8,700,000			7,300,000
Long-term Risk Management Liabilities	[9]	112,200,000			96,300,000
Total Liabilities	[9]	120,900,000			103,600,000
Total MTM Derivative Contract Net Assets (Liabilities)	[9]	(120,900,000)			(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	[9]	6,400,000			15,800,000
Long-term Risk Management Assets	[9]	0			0
Total Assets	[9]	6,400,000			15,800,000
Current Risk Management Liabilities	[9]	100,000			0
Long-term Risk Management Liabilities	[9]	0			0
Total Liabilities	[9]	100,000			0
Total MTM Derivative Contract Net Assets (Liabilities)	[9]	6,300,000			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	[9]	2,600,000			6,400,000
Long-term Risk Management Assets	[9]	0			0
Total Assets	[9]	2,600,000			6,400,000
Current Risk Management Liabilities	[9]	2,200,000			1,900,000
Long-term Risk Management Liabilities	[9]	2,900,000			3,100,000
Total Liabilities	[9]	5,100,000			5,000,000
Total MTM Derivative Contract Net Assets (Liabilities)	[9]	$ (2,500,000)			$ 1,400,000
Power [Member]
Commodity:
Derivative, Energy Notional Amount | MWh		305.4			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		38.7			61
Power [Member] | Indiana Michigan Power Co [Member]
Commodity:
Derivative, Energy Notional Amount | MWh		18.5			26.8
Power [Member] | Ohio Power Co [Member]
Commodity:
Derivative, Energy Notional Amount | MWh		3.2			7.1
Power [Member] | Public Service Co Of Oklahoma [Member]
Commodity:
Derivative, Energy Notional Amount | MWh		5.9			14.9
Power [Member] | Southwestern Electric Power Co [Member]
Commodity:
Derivative, Energy Notional Amount | MWh		1.7			4.4
Natural Gas [Member]
Commodity:
Derivative, Energy Notional Amount | MMBTU		42.3			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		10.7			11.6
Heating Oil and Gasoline [Member]
Commodity:
Derivative, Volume Notional Amount | gal		5			6.9
Heating Oil and Gasoline [Member] | AEP Texas Inc. [Member]
Commodity:
Derivative, Volume Notional Amount | gal		1.3			1.8
Heating Oil and Gasoline [Member] | Appalachian Power Co [Member]
Commodity:
Derivative, Volume Notional Amount | gal		0.8			1.1
Heating Oil and Gasoline [Member] | Indiana Michigan Power Co [Member]
Commodity:
Derivative, Volume Notional Amount | gal		0.5			0.6
Heating Oil and Gasoline [Member] | Ohio Power Co [Member]
Commodity:
Derivative, Volume Notional Amount | gal		1			1.4
Heating Oil and Gasoline [Member] | Public Service Co Of Oklahoma [Member]
Commodity:
Derivative, Volume Notional Amount | gal		0.5			0.7
Heating Oil and Gasoline [Member] | Southwestern Electric Power Co [Member]
Commodity:
Derivative, Volume Notional Amount | gal		0.7			0.9
Interest Rate Contract [Member]
Commodity:
Derivative, Notional Amount		$ 137,100,000			$ 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
Vertically Integrated Utilities Revenues [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		400,000		300,000
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
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
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
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
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
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
Generation and Marketing Revenues [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		(10,300,000)		2,700,000
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
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
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
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
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
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
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
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
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		200,000		(100,000)
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		300,000
Electric Generation, Transmission and Distribution Revenues [Member] | Ohio Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0
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
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		0		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		100,000		1,400,000
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
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		100,000		0
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		0		0
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
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
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
Other Operation Expense [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		(200,000)		(400,000)
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		(100,000)		(100,000)
Other Operation Expense [Member] | Appalachian Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		(100,000)
Other Operation Expense [Member] | Indiana Michigan Power Co [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0
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		(100,000)		(100,000)
Other Operation Expense [Member] | Public Service Co Of Oklahoma [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0
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		0		0
Maintenance Expense [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		(200,000)		(500,000)
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		(100,000)		(100,000)
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		(100,000)		0
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		0		0
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		0		(100,000)
Maintenance Expense [Member] | Public Service Co Of Oklahoma [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts		0		0
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		0		(100,000)
Regulatory Assets [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[10]	(33,900,000)		(6,400,000)
Regulatory Assets [Member] | AEP Texas Inc. [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[10]	(1,200,000)		600,000
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	[10]	(8,900,000)		(2,100,000)
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	[10]	(700,000)		300,000
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	[10]	(18,400,000)		(8,900,000)
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	[10]	(500,000)		500,000
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	[10]	(2,000,000)		(100,000)
Regulatory Liabilities [Member]
Amount of Gain (Loss) Recognized on Risk Management Contracts
Amount of Gain (Loss) Recognized on Risk Management Contracts	[10]	11,200,000		(22,000,000)
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	[10]	0		0
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	[10]	(7,300,000)		(31,700,000)
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	[10]	3,200,000		6,600,000
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	[10]	3,500,000		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	[10]	8,100,000		6,200,000
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	[10]	$ 3,300,000		$ 4,700,000
[1]	Amounts included on the balance sheets within Long-term Debt Due within One Year and Long-term Debt, respectively.
[2]	Gain (Loss) is included in Interest Expense on the statements of income.
[3]	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.’’
[4]	The March 31, 2020 maturity of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), is as follows: Level 1 matures $(1) million in periods 2021-2023; Level 2 matures $(30) million in 2020, $(9) million in periods 2021-2023 and $(1) million in periods 2024-2025; Level 3 matures $37 million in 2020, $36 million in periods 2021-2023, $25 million in periods 2024-2025 and $(20) million in periods 2026-2032. Risk management commodity contracts are substantially comprised of power contracts.
[5]	The December 31, 2019 maturity of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), is as follows: Level 2 matures $(7) million in 2020 and $(3) million in periods 2021-2023; Level 3 matures $96 million in 2020, $36 million in periods 2021-2023, $25 million in periods 2024-2025 and $(12) million in periods 2026-2032. Risk management commodity contracts are substantially comprised of power contracts.
[6]	Substantially comprised of power contracts for the Registrant Subsidiaries.
[7]	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.”
[8]	Amounts include counterparty netting of risk management and hedging contracts and associated cash collateral in accordance with the accounting guidance for “Derivatives and Hedging.”
[9]	All derivative contracts subject to a master netting arrangement or similar agreement are offset in the statement of financial position.
[10]	Represents realized and unrealized gains and losses subject to regulatory accounting treatment recorded as either current or noncurrent on the balance sheets.

Fair Value Long-term Debt, Othe

Fair Value Long-term Debt, Other Temporary Investments, Nuclear Trusts (Details) - USD ($) $ in Millions		3 Months Ended		12 Months Ended
		Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		$ 27,892.7		$ 26,725.5
Long Term Debt, Fair Value	[1]	29,776.6		30,172
Other Temporary Investments
Cost		289.8		367.1
Gross Unrealized Gains		11.6		21.4
Gross Unrealized Losses		0		0
Other Short-term Investments		301.4		388.5
Debt and Equity Securities Within Other Temporary Investments
Proceeds from Investment Sales		23.2	$ 0
Purchases of Investments		6.7	0.1
Gross Realized Gains on Investment Sales		2	0
Gross Realized Losses on Investment Sales		0.1	0
Nuclear Trust Fund Investments
Fair Value		2,679.2		2,975.7
Contractual Maturities, Fair Value of Debt Securities
Fair Value		2,679.2		2,975.7
Spent Nuclear Fuel and Decommissioning Trusts [Member]
Unrealized Gain on Securities		801		1,100
Nuclear Trust Fund Investments
Gross Unrealized Gains		906.5		1,205.9
Other-Than-Temporary Impairments		(7.4)		(7.9)
Securities Activity Within Decommissioning and SNF Trusts
Proceeds from Investment Sales		612.4	111.9
Purchases of Investments		626	130.3
Gross Realized Gains on Investment Sales		10.9	12.3
Gross Realized Losses on Investment Sales		17	13.8
Contractual Maturities, Fair Value of Debt Securities
Within 1 year		238.9
After 1 year through 5 years		404.5
After 5 years through 10 years		282.5
After 10 years		312.6
Fair Value Measurements (Textuals)
Adjusted Cost of Debt Securities		1,100		1,100
Adjusted Cost of Domestic Equity Securities		616		623
Unrealized Loss on Securities		23		5
Cash [Member]
Other Temporary Investments
Cost	[2]	151.9		214.7
Gross Unrealized Gains	[2]	0		0
Gross Unrealized Losses	[2]	0		0
Other Short-term Investments	[2],[3]	151.9		214.7
Fixed Income Funds [Member]
Nuclear Trust Fund Investments
Fair Value		1,238.5		1,192.5
Contractual Maturities, Fair Value of Debt Securities
Fair Value		1,238.5		1,192.5
Fixed Income Funds [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains		128.9		61.5
Other-Than-Temporary Impairments		(7.4)		(7.9)
Mutual Funds Fixed Income [Member]
Other Temporary Investments
Cost	[4]	118.6		123.2
Gross Unrealized Gains	[4]	0.4		0.1
Gross Unrealized Losses	[4]	0		0
Other Short-term Investments	[4]	119		123.3
Domestic [Member]
Nuclear Trust Fund Investments
Fair Value	[5]	1,393.8		1,767.9
Contractual Maturities, Fair Value of Debt Securities
Fair Value	[5]	1,393.8		1,767.9
Domestic [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains	[6]	777.6		1,144.4
Other-Than-Temporary Impairments		0		0
Mutual Funds Equity [Member]
Other Temporary Investments
Cost		19.3		29.2
Gross Unrealized Gains		11.2		21.3
Gross Unrealized Losses		0		0
Other Short-term Investments	[5]	30.5		50.5
Cash and Cash Equivalents [Member]
Nuclear Trust Fund Investments
Fair Value	[7]	46.9		15.3
Contractual Maturities, Fair Value of Debt Securities
Fair Value	[7]	46.9		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
US Government Agencies Debt Securities [Member]
Nuclear Trust Fund Investments
Fair Value		1,026.1		1,112.5
Contractual Maturities, Fair Value of Debt Securities
Fair Value		1,026.1		1,112.5
US Government Agencies Debt Securities [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains		121.4		55.5
Other-Than-Temporary Impairments		(5.6)		(6.1)
Corporate Debt [Member]
Nuclear Trust Fund Investments
Fair Value		62.7		72.4
Contractual Maturities, Fair Value of Debt Securities
Fair Value		62.7		72.4
Corporate Debt [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains		6		5.3
Other-Than-Temporary Impairments		(1.6)		(1.6)
State and Local Jurisdiction [Member]
Nuclear Trust Fund Investments
Fair Value		149.7		7.6
Contractual Maturities, Fair Value of Debt Securities
Fair Value		149.7		7.6
State and Local Jurisdiction [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains		1.5		0.7
Other-Than-Temporary Impairments		(0.2)		(0.2)
AEP Texas Inc. [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		4,445.4		4,558.4
Long Term Debt, Fair Value		4,637.3		4,981.5
AEP Transmission Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		3,427.8		3,427.3
Long Term Debt, Fair Value		3,680.7		3,868
Appalachian Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		4,352.4		4,363.8
Long Term Debt, Fair Value		4,959		5,253.1
Indiana Michigan Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		3,028		3,050.2
Long Term Debt, Fair Value		3,318.2		3,453.8
Nuclear Trust Fund Investments
Fair Value		2,679.2		2,975.7
Contractual Maturities, Fair Value of Debt Securities
Fair Value		2,679.2		2,975.7
Indiana Michigan Power Co [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Unrealized Gain on Securities		801		1,149
Nuclear Trust Fund Investments
Gross Unrealized Gains		906.5		1,205.9
Other-Than-Temporary Impairments		(7.4)		(7.9)
Securities Activity Within Decommissioning and SNF Trusts
Proceeds from Investment Sales		612.4	111.9
Purchases of Investments		626	130.3
Gross Realized Gains on Investment Sales		10.9	12.3
Gross Realized Losses on Investment Sales		17	$ 13.8
Contractual Maturities, Fair Value of Debt Securities
Within 1 year		238.9
After 1 year through 5 years		404.5
After 5 years through 10 years		282.5
After 10 years		312.6
Fair Value Measurements (Textuals)
Adjusted Cost of Debt Securities		1,000		1,000
Adjusted Cost of Domestic Equity Securities		616		623
Unrealized Loss on Securities		23		5
Indiana Michigan Power Co [Member] | Fixed Income Funds [Member]
Nuclear Trust Fund Investments
Fair Value		1,238.5		1,192.5
Contractual Maturities, Fair Value of Debt Securities
Fair Value		1,238.5		1,192.5
Indiana Michigan Power Co [Member] | Fixed Income Funds [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains		128.9		61.5
Other-Than-Temporary Impairments		(7.4)		(7.9)
Indiana Michigan Power Co [Member] | Domestic [Member]
Nuclear Trust Fund Investments
Fair Value	[5]	1,393.8		1,767.9
Contractual Maturities, Fair Value of Debt Securities
Fair Value	[5]	1,393.8		1,767.9
Indiana Michigan Power Co [Member] | Domestic [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains	[6]	777.6		1,144.4
Other-Than-Temporary Impairments	[6]	0		0
Indiana Michigan Power Co [Member] | Cash and Cash Equivalents [Member]
Nuclear Trust Fund Investments
Fair Value	[7]	46.9		15.3
Contractual Maturities, Fair Value of Debt Securities
Fair Value	[7]	46.9		15.3
Indiana Michigan Power Co [Member] | 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
Indiana Michigan Power Co [Member] | US Government Agencies Debt Securities [Member]
Nuclear Trust Fund Investments
Fair Value		1,026.1		1,112.5
Contractual Maturities, Fair Value of Debt Securities
Fair Value		1,026.1		1,112.5
Indiana Michigan Power Co [Member] | US Government Agencies Debt Securities [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains		121.4		55.5
Other-Than-Temporary Impairments		(5.6)		(6.1)
Indiana Michigan Power Co [Member] | Corporate Debt [Member]
Nuclear Trust Fund Investments
Fair Value		62.7		72.4
Contractual Maturities, Fair Value of Debt Securities
Fair Value		62.7		72.4
Indiana Michigan Power Co [Member] | Corporate Debt [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains		6		5.3
Other-Than-Temporary Impairments		(1.6)		(1.6)
Indiana Michigan Power Co [Member] | State and Local Jurisdiction [Member]
Nuclear Trust Fund Investments
Fair Value		149.7		7.6
Contractual Maturities, Fair Value of Debt Securities
Fair Value		149.7		7.6
Indiana Michigan Power Co [Member] | State and Local Jurisdiction [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member]
Nuclear Trust Fund Investments
Gross Unrealized Gains		1.5		0.7
Other-Than-Temporary Impairments		(0.2)		(0.2)
Ohio Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		2,429.1		2,082
Long Term Debt, Fair Value		2,795.3		2,554.3
Public Service Co Of Oklahoma [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		1,386.3		1,386.2
Long Term Debt, Fair Value		1,553.9		1,603.3
Southwestern Electric Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding		2,654.4		2,655.6
Long Term Debt, Fair Value		2,776.5		2,927.9
Equity Units [Member]
Book Values and Fair Values of Long - term Debt
Long Term Debt, Fair Value		$ 777		$ 871
[1]	The fair value amount includes debt related to AEP’s Equity Units issued in March 2019 and has a fair value of $777 million and $871 million as of March 31, 2020 and December 31, 2019 , respectively. See “Equity Units” section of Note 12 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 $801 million and $1.1 billion and unrealized losses of $23 million and $5 million as of March 31, 2020 and December 31, 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 Assets and Liabiliti

Fair Value Assets and Liabilities (Details) - USD ($)		3 Months Ended
		Mar. 31, 2020		Mar. 31, 2019	Dec. 31, 2019
Assets, Fair Value Disclosure
Other Short-term Investments		$ 301,400,000			$ 388,500,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		2,679,200,000			2,975,700,000
Total Assets		3,434,700,000			3,803,600,000
Risk Management Assets
Risk Management Assets		454,100,000			439,400,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		448,700,000			376,100,000
Changes in the Fair Value of Net Trading Derivatives and other investments
Beginning Balance		109,900,000		$ 131,200,000
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	[1],[2]	900,000		(23,000,000)
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	[1]	10,900,000		8,500,000
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	[3]	(4,100,000)		(15,800,000)
Settlements		(59,200,000)		(54,500,000)
Transfers into Level 3	[4],[5]	(500,000)		100,000
Transfers out of Level 3	[5]	5,300,000		(1,200,000)
Changes in Fair Value Allocated to Regulated Jurisdiction	[6]	(20,700,000)		(7,200,000)
Ending Balance		42,500,000		38,100,000
Other [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		23,800,000			17,100,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		9,900,000			8,600,000
Total Assets		(312,000,000)			(385,500,000)
Risk Management Assets
Risk Management Assets		(345,700,000)			(411,200,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities		(421,500,000)			(445,500,000)
Level 1 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		277,600,000			371,400,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,430,800,000			1,774,600,000
Total Assets		1,712,100,000			2,150,000,000
Risk Management Assets
Risk Management Assets		3,700,000			4,000,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		4,900,000			3,800,000
Level 2 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		0			0
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,238,500,000			1,192,500,000
Total Assets		1,684,300,000			1,666,700,000
Risk Management Assets
Risk Management Assets		445,800,000			474,200,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		557,500,000			555,300,000
Level 3 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		0			0
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Total Assets		350,300,000			372,400,000
Risk Management Assets
Risk Management Assets		350,300,000			372,400,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		307,800,000			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		(30,000,000)			(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		37,000,000			96,000,000
2021 - 2023 [Member] | Level 1 [Member]
Fair Value Measurements 1 (Textuals)
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		(1,000,000)
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		(9,000,000)			(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			36,000,000
2024 - 2025 [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)
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			25,000,000
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		(20,000,000)			(12,000,000)
Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	[7]	379,100,000	[8]		408,800,000	[9]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7]	266,600,000	[8]		239,000,000	[9]
Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	[7]	(340,500,000)	[8]		(404,500,000)	[9]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7]	(416,300,000)	[8]		(438,800,000)	[9]
Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[7]	3,700,000	[8]		4,000,000	[9]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7]	4,900,000	[8]		3,800,000	[9]
Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[7]	369,800,000	[8]		440,100,000	[9]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7]	410,100,000	[8]		450,000,000	[9]
Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[7]	346,100,000	[8]		369,200,000	[9]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7]	267,900,000	[8]		224,000,000	[9]
Energy Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		321,200,000			296,700,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		284,600,000			249,300,000
Energy Contracts [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10]	(0.05)			(0.05)
Energy Contracts [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10]	135.24			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]	29.17			31.31
Natural Gas Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		5,100,000			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]	1.37			1.89
Natural Gas Contracts [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[12]	2.51			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]	2.13			2.19
FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		29,100,000			75,700,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		18,100,000			8,300,000
FTRs [Member] | Level 3 [Member] | Low [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10]	(10.12)			(8.52)
FTRs [Member] | Level 3 [Member] | High [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10]	4.17			9.34
FTRs [Member] | Level 3 [Member] | Weighted Average [Member]
Level 3 Quantitative Information
Fair Value Significant Unobservable Input Price Per Unit	[10],[11]	(0.31)			0.42
Commodity Hedges [Member]
Risk Management Assets
Risk Management Assets	[7]	17,700,000			11,500,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7]	176,800,000			137,100,000
Commodity Hedges [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	[7]	(5,200,000)			(6,700,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7]	(5,200,000)			(6,700,000)
Commodity Hedges [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[7]	0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7]	0			0
Commodity Hedges [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[7]	18,700,000			15,000,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7]	142,100,000			105,300,000
Commodity Hedges [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[7]	4,200,000			3,200,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7]	39,900,000			38,500,000
Interest Rate [Member]
Risk Management Assets
Risk Management Assets		300,000			4,600,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		5,300,000
Interest Rate [Member] | Other [Member]
Risk Management Assets
Risk Management Assets		0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		0
Interest Rate [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets		0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		0
Interest Rate [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets		300,000			4,600,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		5,300,000
Interest Rate [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		0
Fair Value Hedges [Member]
Risk Management Assets
Risk Management Assets		57,000,000			14,500,000
Fair Value Hedges [Member] | Other [Member]
Risk Management Assets
Risk Management Assets		0			0
Fair Value Hedges [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets		0			0
Fair Value Hedges [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets		57,000,000			14,500,000
Fair Value Hedges [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		0			0
AEP Texas Inc. [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		100,100,000			154,700,000
AEP Texas Inc. [Member] | Other [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0			0
AEP Texas Inc. [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		100,100,000			154,700,000
AEP Texas Inc. [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0			0
AEP Texas Inc. [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0			0
AEP Texas Inc. [Member] | Risk Management Commodity Contracts [Member]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7]	0
AEP Texas Inc. [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7]	(1,200,000)
AEP Texas Inc. [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7]	0
AEP Texas Inc. [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7]	1,200,000
AEP Texas Inc. [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7]	0
Appalachian Power Co [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		15,700,000			23,500,000
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		33,900,000			63,000,000
Risk Management Assets
Risk Management Assets		18,200,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		15,100,000
Changes in the Fair Value of Net Trading Derivatives and other investments
Beginning Balance		37,700,000		57,800,000
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	[1],[2]	(9,200,000)		(29,000,000)
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	[1]	0		0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	[3]	0		0
Settlements		(21,900,000)		(17,800,000)
Transfers into Level 3	[4],[5]	0		0
Transfers out of Level 3	[5]	700,000		(700,000)
Changes in Fair Value Allocated to Regulated Jurisdiction	[6]	(700,000)		(2,900,000)
Ending Balance		6,600,000		7,400,000
Appalachian Power Co [Member] | Other [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0			0
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		(54,200,000)			(85,600,000)
Risk Management Assets
Risk Management Assets		(54,200,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities		(59,500,000)
Appalachian Power Co [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		15,700,000			23,500,000
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		15,700,000			23,500,000
Risk Management Assets
Risk Management Assets		0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		0
Appalachian Power Co [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0			0
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		55,300,000			84,600,000
Risk Management Assets
Risk Management Assets		55,300,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		64,100,000
Appalachian Power Co [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Cash and Cash Equivalents		0			0
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		17,100,000			40,500,000
Risk Management Assets
Risk Management Assets		17,100,000			40,500,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		10,500,000			2,800,000
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	[7],[13]	17,900,000			39,500,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	9,800,000			1,900,000
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	[7],[13]	(54,200,000)			(85,600,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	(59,500,000)			(84,900,000)
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[7],[13]	0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	0			0
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[7],[13]	55,000,000			84,600,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	58,800,000			84,000,000
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[7],[13]	17,100,000			40,500,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	10,500,000			2,800,000
Appalachian Power Co [Member] | Energy Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		5,300,000			5,700,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		2,200,000			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]	9.95			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]	42.15			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]	21.81			25.92
Appalachian Power Co [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		11,800,000			34,800,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		8,300,000			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			(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]	3.44			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]	0.42			1.70
Appalachian Power Co [Member] | Interest Rate [Member]
Risk Management Assets
Risk Management Assets		300,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		5,300,000
Appalachian Power Co [Member] | Interest Rate [Member] | Other [Member]
Risk Management Assets
Risk Management Assets		0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		0
Appalachian Power Co [Member] | Interest Rate [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets		0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		0
Appalachian Power Co [Member] | Interest Rate [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets		300,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		5,300,000
Appalachian Power Co [Member] | Interest Rate [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		0
Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		2,679,200,000			2,975,700,000
Total Assets		2,686,000,000			2,985,600,000
Changes in the Fair Value of Net Trading Derivatives and other investments
Beginning Balance		5,800,000		8,900,000
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	[1],[2]	200,000		0
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	[1]	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
Settlements		(4,000,000)		(5,100,000)
Transfers into Level 3	[4],[5]	0		0
Transfers out of Level 3	[5]	400,000		(400,000)
Changes in Fair Value Allocated to Regulated Jurisdiction	[6]	(300,000)		1,000,000
Ending Balance		2,100,000		4,400,000
Indiana Michigan Power Co [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		9,900,000			8,600,000
Total Assets		(26,300,000)			(49,000,000)
Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,430,800,000			1,774,600,000
Total Assets		1,430,800,000			1,774,600,000
Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,238,500,000			1,192,500,000
Total Assets		1,276,600,000			1,252,000,000
Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Total Assets		4,900,000			8,000,000
Risk Management Assets
Risk Management Assets		4,900,000			8,000,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		2,800,000			2,200,000
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	[7],[13]	6,800,000			9,900,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	1,800,000			500,000
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	[7],[13]	(36,200,000)			(57,600,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	(37,200,000)			(55,100,000)
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[7],[13]	0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	0			0
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[7],[13]	38,100,000			59,500,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	36,200,000			53,400,000
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[7],[13]	4,900,000			8,000,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	2,800,000			2,200,000
Indiana Michigan Power Co [Member] | Energy Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		3,200,000			3,400,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		1,300,000			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]	9.95			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]	42.15			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]	21.81			25.92
Indiana Michigan Power Co [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		1,700,000			4,600,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		1,500,000			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]	(0.51)			(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]	2.77			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]	0.12			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)
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	[1],[2]	(300,000)		(400,000)
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	[1]	0		0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	[3]	0		0
Settlements		2,500,000		1,800,000
Transfers into Level 3	[4],[5]	0		0
Transfers out of Level 3	[5]	0		0
Changes in Fair Value Allocated to Regulated Jurisdiction	[6]	(19,500,000)		(8,100,000)
Ending Balance		(120,900,000)		(106,100,000)
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	120,900,000			103,600,000
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	(900,000)			0
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	0			0
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	900,000			0
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	120,900,000			103,600,000
Ohio Power Co [Member] | Energy Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		120,900,000			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]	12.57			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]	42.71			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]	26.31			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
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	[1],[2]	8,000,000		6,800,000
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	[1]	0		0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	[3]	0		0
Settlements		(17,700,000)		(13,000,000)
Transfers into Level 3	[4],[5]	0		0
Transfers out of Level 3	[5]	0		0
Changes in Fair Value Allocated to Regulated Jurisdiction	[6]	200,000		1,100,000
Ending Balance		6,300,000		4,400,000
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	[7],[13]	6,400,000			15,800,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	100,000			0
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	[7],[13]	(300,000)			(500,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	(800,000)			(500,000)
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[7],[13]	0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	0			0
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[7],[13]	0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	500,000			0
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[7],[13]	6,700,000			16,300,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	400,000			500,000
Public Service Co Of Oklahoma [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		6,700,000			16,300,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		400,000			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]	(7.07)			(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]	0.95			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]	(2.38)			(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
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	[1],[2]	1,900,000		3,300,000
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	[1]	0		0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss)	[3]	0		0
Settlements		(5,300,000)		(7,300,000)
Transfers into Level 3	[4],[5]	0		0
Transfers out of Level 3	[5]	0		0
Changes in Fair Value Allocated to Regulated Jurisdiction	[6]	(500,000)		1,700,000
Ending Balance		(2,500,000)		$ 0
Southwestern Electric Power Co [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		2,700,000			6,500,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		5,200,000			5,100,000
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	[7],[13]	2,600,000			6,400,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	5,100,000			5,000,000
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member] | Other [Member]
Risk Management Assets
Risk Management Assets	[7],[13]	(100,000)			(100,000)
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	(700,000)			(100,000)
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[7],[13]	0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	0			0
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[7],[13]	0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	600,000			0
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[7],[13]	2,700,000			6,500,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities	[7],[13]	5,200,000			5,100,000
Southwestern Electric Power Co [Member] | Natural Gas Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		0			0
Liabilities, Fair Value Disclosure
Risk Management Liabilities		5,100,000			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]	1.37			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]	2.51			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]	2.13			2.18
Southwestern Electric Power Co [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		2,700,000			6,500,000
Liabilities, Fair Value Disclosure
Risk Management Liabilities		100,000			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]	(7.07)			(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]	0.95			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]	(2.38)			(2.31)
Cash [Member]
Assets, Fair Value Disclosure
Other Short-term Investments	[14],[15]	151,900,000			214,700,000
Cash [Member] | Other [Member]
Assets, Fair Value Disclosure
Other Short-term Investments	[15]	23,800,000			17,100,000
Cash [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments	[15]	128,100,000			197,600,000
Cash [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments	[15]	0			0
Cash [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments	[15]	0			0
Fixed Income Funds [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,238,500,000			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		1,238,500,000			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		1,238,500,000			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		1,238,500,000			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
Mutual Funds Fixed Income [Member]
Assets, Fair Value Disclosure
Other Short-term Investments	[16]	119,000,000			123,300,000
Mutual Funds Fixed Income [Member] | Other [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		0			0
Mutual Funds Fixed Income [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		119,000,000			123,300,000
Mutual Funds Fixed Income [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		0			0
Mutual Funds Fixed Income [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments		0			0
Mutual Funds Equity [Member]
Assets, Fair Value Disclosure
Other Short-term Investments	[17]	30,500,000			50,500,000
Mutual Funds Equity [Member] | Other [Member]
Assets, Fair Value Disclosure
Other Short-term Investments	[17]	0			0
Mutual Funds Equity [Member] | Level 1 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments	[17]	30,500,000			50,500,000
Mutual Funds Equity [Member] | Level 2 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments	[17]	0			0
Mutual Funds Equity [Member] | Level 3 [Member]
Assets, Fair Value Disclosure
Other Short-term Investments	[17]	0			0
Cash and Cash Equivalents [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[18]	46,900,000			15,300,000
Cash and Cash Equivalents [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[18]	9,900,000			8,600,000
Cash and Cash Equivalents [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[18]	37,000,000			6,700,000
Cash and Cash Equivalents [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[18]	0			0
Cash and Cash Equivalents [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[18]	0			0
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[18]	46,900,000			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	[18]	9,900,000			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	[18]	37,000,000			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	[18]	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	[18]	0			0
US Government Agencies Debt Securities [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,026,100,000			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		1,026,100,000			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		1,026,100,000			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		1,026,100,000			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 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		62,700,000			72,400,000
Corporate Debt [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Corporate Debt [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Corporate Debt [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		62,700,000			72,400,000
Corporate Debt [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Corporate Debt [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		62,700,000			72,400,000
Corporate Debt [Member] | Indiana Michigan Power Co [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Corporate Debt [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 [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		62,700,000			72,400,000
Corporate Debt [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
State and Local Jurisdiction [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		149,700,000			7,600,000
State and Local Jurisdiction [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
State and Local Jurisdiction [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
State and Local Jurisdiction [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		149,700,000			7,600,000
State and Local Jurisdiction [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		149,700,000			7,600,000
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		149,700,000			7,600,000
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0
Domestic [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[17]	1,393,800,000			1,767,900,000
Domestic [Member] | Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[17]	0			0
Domestic [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[17]	1,393,800,000			1,767,900,000
Domestic [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[17]	0			0
Domestic [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[17]	0			0
Domestic [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[17]	1,393,800,000			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	[17]	0			0
Domestic [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[17]	1,393,800,000			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	[17]	0			0
Domestic [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[17]	$ 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 March 31, 2020 maturity of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), is as follows: Level 1 matures $(1) million in periods 2021-2023; Level 2 matures $(30) million in 2020, $(9) million in periods 2021-2023 and $(1) million in periods 2024-2025; Level 3 matures $37 million in 2020, $36 million in periods 2021-2023, $25 million in periods 2024-2025 and $(20) million in periods 2026-2032. Risk management commodity contracts are substantially comprised of power contracts.
[9]	The December 31, 2019 maturity of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), is as follows: Level 2 matures $(7) million in 2020 and $(3) million in periods 2021-2023; Level 3 matures $96 million in 2020, $36 million in periods 2021-2023, $25 million in periods 2024-2025 and $(12) million in periods 2026-2032. Risk management commodity contracts are substantially comprised of power contracts.
[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]	Substantially comprised of power contracts for the Registrant Subsidiaries.
[14]	Primarily represents amounts held for the repayment of debt.
[15]	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.
[16]	Primarily short and intermediate maturities which may be sold and do not contain maturity dates.
[17]	Amounts represent publicly traded equity securities and equity-based mutual funds.
[18]	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	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. Federal Statutory Rate	21.00%	21.00%
State Income Tax, net of Federal benefit	2.50%	2.10%
Tax Reform Excess ADIT Reversal	(9.40%)	(13.60%)
Production and Investment Tax Credits	(4.30%)	(2.20%)
Flow Through	0.50%	(0.20%)
AFUDC Equity	(1.40%)	(1.40%)
Parent Company Loss	0.00%	0.00%
Discrete Tax Adjustments	0.00%	1.70%
Other	(0.40%)	(0.20%)
Effective Income Tax Rate	8.50%	7.20%
Income Taxes (Textuals) [Abstract]
Deferred Tax Assets, Tax Credit Carryforwards, Alternative Minimum Tax	$ 20
AEP Texas Inc. [Member]
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. Federal Statutory Rate	21.00%	21.00%
State Income Tax, net of Federal benefit	1.50%	1.50%
Tax Reform Excess ADIT Reversal	(6.20%)	(7.60%)
Production and Investment Tax Credits	(0.40%)	(1.00%)
Flow Through	0.10%	0.30%
AFUDC Equity	(2.60%)	(1.60%)
Parent Company Loss	(0.20%)	(2.30%)
Discrete Tax Adjustments	0.00%	0.00%
Other	0.30%	0.10%
Effective Income Tax Rate	13.50%	10.40%
AEP Transmission Co [Member]
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. Federal Statutory Rate	21.00%	21.00%
State Income Tax, net of Federal benefit	2.90%	2.90%
Tax Reform Excess ADIT Reversal	0.40%	0.40%
Production and Investment Tax Credits	0.00%	0.00%
Flow Through	0.50%	0.20%
AFUDC Equity	(2.60%)	(2.50%)
Parent Company Loss	(0.90%)	(1.00%)
Discrete Tax Adjustments	0.00%	0.00%
Other	0.00%	(0.10%)
Effective Income Tax Rate	21.30%	20.90%
Appalachian Power Co [Member]
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. Federal Statutory Rate	21.00%	21.00%
State Income Tax, net of Federal benefit	3.00%	3.40%
Tax Reform Excess ADIT Reversal	(13.00%)	(42.20%)
Production and Investment Tax Credits	0.00%	0.00%
Flow Through	1.50%	(0.90%)
AFUDC Equity	(1.00%)	(1.00%)
Parent Company Loss	(3.30%)	(2.40%)
Discrete Tax Adjustments	0.00%	0.40%
Other	0.10%	(0.30%)
Effective Income Tax Rate	8.30%	(22.00%)
Income Taxes (Textuals) [Abstract]
Deferred Tax Assets, Tax Credit Carryforwards, Alternative Minimum Tax	$ 7
Indiana Michigan Power Co [Member]
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. Federal Statutory Rate	21.00%	21.00%
State Income Tax, net of Federal benefit	3.20%	2.00%
Tax Reform Excess ADIT Reversal	(19.60%)	(17.40%)
Production and Investment Tax Credits	(1.90%)	(2.00%)
Flow Through	0.20%	(2.40%)
AFUDC Equity	(1.10%)	(1.90%)
Parent Company Loss	(3.90%)	(1.80%)
Discrete Tax Adjustments	2.70%	0.00%
Other	(0.20%)	(0.30%)
Effective Income Tax Rate	0.40%	(2.80%)
Ohio Power Co [Member]
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. Federal Statutory Rate	21.00%	21.00%
State Income Tax, net of Federal benefit	0.70%	0.90%
Tax Reform Excess ADIT Reversal	(10.20%)	(7.60%)
Production and Investment Tax Credits	0.00%	0.00%
Flow Through	1.00%	0.70%
AFUDC Equity	(1.00%)	(0.70%)
Parent Company Loss	(0.10%)	(1.10%)
Discrete Tax Adjustments	0.00%	0.00%
Other	0.00%	0.20%
Effective Income Tax Rate	11.40%	13.40%
Income Taxes (Textuals) [Abstract]
Deferred Tax Assets, Tax Credit Carryforwards, Alternative Minimum Tax	$ 9
Public Service Co Of Oklahoma [Member]
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. Federal Statutory Rate	21.00%	21.00%
State Income Tax, net of Federal benefit	4.60%	4.60%
Tax Reform Excess ADIT Reversal	(23.10%)	(21.90%)
Production and Investment Tax Credits	(1.30%)	(1.70%)
Flow Through	0.60%	0.60%
AFUDC Equity	(0.70%)	(0.40%)
Parent Company Loss	(2.20%)	(1.80%)
Discrete Tax Adjustments	0.00%	0.00%
Other	0.10%	0.20%
Effective Income Tax Rate	(1.00%)	0.60%
Southwestern Electric Power Co [Member]
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. Federal Statutory Rate	21.00%	21.00%
State Income Tax, net of Federal benefit	2.70%	0.20%
Tax Reform Excess ADIT Reversal	(94.70%)	(17.00%)
Production and Investment Tax Credits	(0.50%)	(0.80%)
Flow Through	(1.00%)	(0.90%)
AFUDC Equity	(0.40%)	(1.10%)
Parent Company Loss	(2.40%)	(0.50%)
Discrete Tax Adjustments	0.00%	0.00%
Other	7.20%	1.50%
Effective Income Tax Rate	(68.10%)	2.40%

Financing Activities (Details)

Financing Activities (Details) - USD ($)		May 06, 2020	Apr. 30, 2020	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Long-term Debt
Senior Unsecured Notes				$ 22,515,800,000		$ 21,180,700,000
Pollution Control Bonds				1,999,200,000		1,998,800,000
Notes Payable				209,400,000		234,300,000
Securitization Bonds				899,100,000		1,025,100,000
Spent Nuclear Fuel Obligation	[1]			280,900,000		279,800,000
Junior Subordinated Notes	[2]			788,600,000		787,800,000
Other Long-term Debt				1,199,700,000		1,219,000,000
Total Long-term Debt Outstanding				27,892,700,000		26,725,500,000
Long-term Debt Due Within One Year				2,109,700,000		1,598,700,000
Long-term Debt				25,783,000,000		25,126,800,000
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt	[3]			1,430,000,000
Repayments of Long-term Debt				$ 300,500,000	$ 220,600,000
Document Period End Date				Mar. 31, 2020
Short-term Debt:
Securitized Debt for Receivables	[4]			$ 724,000,000		710,000,000
Commercial Paper				2,709,600,000		2,110,000,000
Other Short-term Investments				1,000,000,000		0
Notes Payable				30,500,000		18,300,000
Total Short-term Debt				$ 4,464,100,000		$ 2,838,300,000
Securitized Debt for Receivables	[4],[5]			1.75%		2.42%
Comparative Accounts Receivable Information
Effective Interest Rates on Securitization of Accounts Receivable				1.75%	2.71%
Net Uncollectible Accounts Receivable Written Off				$ 4,200,000	$ 6,400,000
Customer Accounts Receivable Managed Portfolio
Accounts Receivable Retained Interest and Pledged as Collateral Less Uncollectible Accounts				850,700,000		$ 841,800,000
Total Principal Outstanding				724,000,000		710,000,000
Delinquent Securitized Accounts Receivable				43,400,000		39,600,000
Bad Debt Reserves Related to Securitization, Sale of Accounts Receivable				34,500,000		32,100,000
Unbilled Receivables Related to Securitization, Sale of Accounts Receivable				219,800,000		266,800,000
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Fees Paid to AEP Credit for Customer Accounts Receivable Sold				3,747,500,000	4,056,800,000
Financing Activities (Textuals)
Trust Fund Assets One Time Fee Obligation for Nuclear Fuel Disposition				$ 324,000,000		$ 323,000,000
Maximum Percentage Debt to Capitalization				67.50%
Total Commitment from Bank Conduits to Finance Receivables				$ 750,000,000
Equity Units Issued				16,100,000
Per Unit Conversion for Equity Units				$ 50
Net Equity Units Issuance Proceeds				785,000,000
Principal Amounts of Junior Subordinated Debt				$ 1,000
Forward Equity Purchase Contract Date				2022
Equity Units Annual Distribution Rate				6.125%
Forward Equity Contract Payment Rate				2.725%
Stockholders' Equity, Other				$ 30,200,000	55,600,000
Maximum Shares Issued Under Equity Units Conversion				9,701,860
Senior Unsecured Notes [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt	[3]			$ 400,000,000
Due Date				2030
Interest Rate (Percentage)				2.30%
Senior Unsecured Notes Two [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt	[3]			$ 400,000,000
Due Date				2050
Interest Rate (Percentage)				3.25%
Commercial Paper [Member]
Short-term Debt:
Weighted Average Interest Rate	[5]			2.24%		2.10%
Short-term Debt [Member]
Short-term Debt:
Weighted Average Interest Rate	[5]			1.53%		0.00%
Loans Payable [Member]
Short-term Debt:
Weighted Average Interest Rate	[5]			2.98%		3.29%
AEP Texas Inc. [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 4,445,400,000		$ 4,558,400,000
Long-term Debt Due Within One Year				289,000,000		392,100,000
Long-term Debt				4,156,400,000		4,166,300,000
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				$ 114,300,000	$ 103,500,000
Financing Activities (Textuals)
Maximum Percentage Debt to Capitalization				67.50%
AEP Texas Inc. [Member] | Utility [Member]
Maximum Interest Rate				2.24%	3.02%
Minimum Interest Rate				1.76%	2.73%
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool				$ 63,900,000
Maximum Loans to Money Pool				199,700,000
Average Borrowings from Money Pool				39,000,000
Average Loans to Money Pool				90,300,000
Net Loans (Borrowings) to/from Money Pool				(63,900,000)
Authorized Short Term Borrowing Limit				$ 500,000,000
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				2.05%	2.86%
Average Interest Rate For Funds Loaned				1.97%	0.00%
AEP Texas Inc. [Member] | Nonutility [Member]
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Loans to Money Pool				$ 7,500,000
Average Loans to Money Pool				7,200,000
Net Loans (Borrowings) to/from Money Pool				$ 7,100,000
Maximum and Minimum Interest Rates
Maximum Interest Rate For Funds Loaned				2.24%	3.02%
Minimum Interest Rate for Funds Loaned				1.76%	2.73%
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Loaned				1.94%	2.87%
AEP Texas Inc. [Member] | Securitization Bonds [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				$ 111,000,000
Due Date				2020
Interest Rate (Percentage)				5.31%
AEP Texas Inc. [Member] | Securitization Bonds Two [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				$ 3,300,000
Due Date				2025
Interest Rate (Percentage)				2.06%
AEP Transmission Co [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 3,427,800,000		3,427,300,000
Long-term Debt				3,427,800,000		3,427,300,000
Financing Activities (Textuals)
Sub-Limit of Secured Debt				$ 50,000,000
Maximum Percentage of Consolidated Tangible Net Assets				10.00%
Tangible Capital to Tangible Assets				3.30%
Maximum Percentage Debt to Capitalization				67.50%
AEP Transmission Co [Member] | Utility [Member]
Maximum Interest Rate				2.24%	3.02%
Minimum Interest Rate				1.76%	2.73%
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool				$ 358,400,000
Maximum Loans to Money Pool				69,800,000
Average Borrowings from Money Pool				257,600,000
Average Loans to Money Pool				32,600,000
Net Loans (Borrowings) to/from Money Pool				(261,000,000)
Authorized Short Term Borrowing Limit	[6]			$ 820,000,000
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				1.95%	2.83%
Average Interest Rate For Funds Loaned				1.91%	2.90%
AEP Transmission Co [Member] | Direct Borrowing [Member]
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool				$ 1,400,000
Maximum Loans to Money Pool				190,300,000
Average Borrowings from Money Pool				1,400,000
Average Loans to Money Pool				125,100,000
Borrowings from Parent				1,300,000
Loans to Parent				93,300,000
Authorized Short Term Borrowing Limit	[7]			$ 50,000,000
Maximum and Minimum Interest Rates
Maximum Interest Rate for Funds Borrowed				2.24%	3.02%
Minimum Interest Rate For Funds Borrowed				1.76%	2.73%
Maximum Interest Rate For Funds Loaned				2.24%	3.02%
Minimum Interest Rate for Funds Loaned				1.76%	2.73%
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				1.94%	2.87%
Average Interest Rate For Funds Loaned				1.94%	2.86%
AEP Transmission Co [Member] | Senior Unsecured Notes [Member] | Subsequent Event [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt			$ 525,000,000
Due Date			2050
Interest Rate (Percentage)			3.65%
Appalachian Power Co [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 4,352,400,000		4,363,800,000
Long-term Debt Due Within One Year				583,300,000		215,600,000
Long-term Debt				3,769,100,000		4,148,200,000
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				12,200,000	$ 12,000,000
Accounts Receivable and Accrued Unbilled Revenues
Accounts Receivable and Accrued Unbilled Revenues				121,800,000		120,900,000
Proceeds from Sale of Receivables
Proceeds from Sale of Receivables to AEP Credit				$ 352,600,000	374,400,000
Financing Activities (Textuals)
Maximum Percentage Debt to Capitalization				67.50%
Appalachian Power Co [Member] | Servicing Contracts [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Fees Paid to AEP Credit for Customer Accounts Receivable Sold				$ 1,700,000	$ 2,200,000
Appalachian Power Co [Member] | Utility [Member]
Maximum Interest Rate				2.24%	3.02%
Minimum Interest Rate				1.76%	2.73%
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool				$ 373,500,000
Maximum Loans to Money Pool				22,200,000
Average Borrowings from Money Pool				303,100,000
Average Loans to Money Pool				22,000,000
Net Loans (Borrowings) to/from Money Pool				(333,500,000)
Authorized Short Term Borrowing Limit				$ 500,000,000
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				1.95%	2.92%
Average Interest Rate For Funds Loaned				1.94%	2.79%
Appalachian Power Co [Member] | Securitization Bonds [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				$ 12,200,000
Due Date				2023
Interest Rate (Percentage)				2.01%
Indiana Michigan Power Co [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 3,028,000,000		3,050,200,000
Long-term Debt Due Within One Year				133,600,000		139,700,000
Long-term Debt				2,894,400,000		2,910,500,000
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				23,700,000	$ 26,500,000
Accounts Receivable and Accrued Unbilled Revenues
Accounts Receivable and Accrued Unbilled Revenues				155,200,000		141,800,000
Proceeds from Sale of Receivables
Proceeds from Sale of Receivables to AEP Credit				471,400,000	478,600,000
Financing Activities (Textuals)
Trust Fund Assets One Time Fee Obligation for Nuclear Fuel Disposition				$ 324,000,000		323,000,000
Maximum Percentage Debt to Capitalization				67.50%
Indiana Michigan Power Co [Member] | Servicing Contracts [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Fees Paid to AEP Credit for Customer Accounts Receivable Sold				$ 2,800,000	$ 2,800,000
Indiana Michigan Power Co [Member] | Utility [Member]
Maximum Interest Rate				2.24%	3.02%
Minimum Interest Rate				1.76%	2.73%
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool				$ 147,500,000
Maximum Loans to Money Pool				13,300,000
Average Borrowings from Money Pool				108,400,000
Average Loans to Money Pool				13,300,000
Net Loans (Borrowings) to/from Money Pool				(90,400,000)
Authorized Short Term Borrowing Limit				$ 500,000,000
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				1.95%	2.80%
Average Interest Rate For Funds Loaned				1.94%	2.87%
Indiana Michigan Power Co [Member] | Notes Payable, Other Payables [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				$ 700,000
Due Date				2020
Interest Rate (Variable)				Variable
Indiana Michigan Power Co [Member] | Notes Payable, Other Payable Two [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				$ 1,500,000
Due Date				2021
Interest Rate (Variable)				Variable
Indiana Michigan Power Co [Member] | Notes Payable, Other Payable Three [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				$ 5,100,000
Due Date				2022
Interest Rate (Variable)				Variable
Indiana Michigan Power Co [Member] | Notes Payable, Other Payable Four [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				$ 3,800,000
Due Date				2022
Interest Rate (Variable)				Variable
Indiana Michigan Power Co [Member] | Notes Payable, Other Payable Five [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				$ 6,200,000
Due Date				2023
Interest Rate (Variable)				Variable
Indiana Michigan Power Co [Member] | Notes Payable, Other Payables Six [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				$ 6,000,000
Due Date				2024
Interest Rate (Variable)				Variable
Indiana Michigan Power Co [Member] | Other Long Term Debt [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				$ 400,000
Due Date				2025
Interest Rate (Percentage)				6.00%
Ohio Power Co [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 2,429,100,000		2,082,000,000
Long-term Debt Due Within One Year				100,000		100,000
Long-term Debt				2,429,000,000		2,081,900,000
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				0	$ 23,400,000
Accounts Receivable and Accrued Unbilled Revenues
Accounts Receivable and Accrued Unbilled Revenues				338,300,000		330,300,000
Proceeds from Sale of Receivables
Proceeds from Sale of Receivables to AEP Credit				570,300,000	636,800,000
Ohio Power Co [Member] | Servicing Contracts [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Fees Paid to AEP Credit for Customer Accounts Receivable Sold				$ 4,800,000	$ 7,800,000
Ohio Power Co [Member] | Utility [Member]
Maximum Interest Rate				2.24%	3.02%
Minimum Interest Rate				1.76%	2.73%
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool				$ 353,900,000
Maximum Loans to Money Pool				32,800,000
Average Borrowings from Money Pool				191,500,000
Average Loans to Money Pool				25,200,000
Net Loans (Borrowings) to/from Money Pool				(29,400,000)
Authorized Short Term Borrowing Limit				$ 500,000,000
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				1.90%	2.85%
Average Interest Rate For Funds Loaned				2.06%	0.00%
Ohio Power Co [Member] | Senior Unsecured Notes [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt	[3]			$ 350,000,000
Due Date				2030
Interest Rate (Percentage)				2.60%
Public Service Co Of Oklahoma [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 1,386,300,000		1,386,200,000
Long-term Debt Due Within One Year				263,200,000		13,200,000
Long-term Debt				1,123,100,000		1,373,000,000
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				100,000	$ 100,000
Accounts Receivable and Accrued Unbilled Revenues
Accounts Receivable and Accrued Unbilled Revenues				93,300,000		101,100,000
Proceeds from Sale of Receivables
Proceeds from Sale of Receivables to AEP Credit				$ 294,900,000	324,500,000
Financing Activities (Textuals)
Maximum Percentage Debt to Capitalization				67.50%
Public Service Co Of Oklahoma [Member] | Servicing Contracts [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Fees Paid to AEP Credit for Customer Accounts Receivable Sold				$ 1,300,000	$ 2,100,000
Public Service Co Of Oklahoma [Member] | Utility [Member]
Maximum Interest Rate				2.24%	3.02%
Minimum Interest Rate				1.76%	2.73%
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool				$ 70,900,000
Maximum Loans to Money Pool				57,100,000
Average Borrowings from Money Pool				25,300,000
Average Loans to Money Pool				28,400,000
Net Loans (Borrowings) to/from Money Pool				(70,900,000)
Authorized Short Term Borrowing Limit				$ 300,000,000
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				2.00%	2.89%
Average Interest Rate For Funds Loaned				1.95%	0.00%
Public Service Co Of Oklahoma [Member] | Other Long Term Debt [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				$ 100,000
Due Date				2027
Interest Rate (Percentage)				3.00%
Southwestern Electric Power Co [Member]
Long-term Debt
Total Long-term Debt Outstanding				$ 2,654,400,000		2,655,600,000
Long-term Debt Due Within One Year				121,200,000		121,200,000
Long-term Debt				2,533,200,000		2,534,400,000
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				1,600,000	$ 55,100,000
Short-term Debt:
Notes Payable				30,500,000		18,300,000
Accounts Receivable and Accrued Unbilled Revenues
Accounts Receivable and Accrued Unbilled Revenues				121,200,000		$ 125,200,000
Proceeds from Sale of Receivables
Proceeds from Sale of Receivables to AEP Credit				$ 365,600,000	371,900,000
Financing Activities (Textuals)
Maximum Percentage Debt to Capitalization				67.50%
Southwestern Electric Power Co [Member] | Servicing Contracts [Member]
Fees Paid to AEP Credit for Customer Accounts Receivable Sold
Fees Paid to AEP Credit for Customer Accounts Receivable Sold				$ 2,100,000	$ 2,600,000
Southwestern Electric Power Co [Member] | Utility [Member]
Maximum Interest Rate				2.24%	3.02%
Minimum Interest Rate				1.76%	2.73%
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Borrowings from Money Pool				$ 152,800,000
Maximum Loans to Money Pool				0
Average Borrowings from Money Pool				105,500,000
Average Loans to Money Pool				0
Net Loans (Borrowings) to/from Money Pool				(148,100,000)
Authorized Short Term Borrowing Limit				$ 350,000,000
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Borrowed				1.95%	2.81%
Average Interest Rate For Funds Loaned				0.00%	2.97%
Southwestern Electric Power Co [Member] | Nonutility [Member]
Money Pool Participants Money Pool Activity And Authorized Borrowing Limits
Maximum Loans to Money Pool				$ 2,100,000
Average Loans to Money Pool				2,100,000
Net Loans (Borrowings) to/from Money Pool				$ 2,100,000
Maximum and Minimum Interest Rates
Maximum Interest Rate For Funds Loaned				2.24%	3.02%
Minimum Interest Rate for Funds Loaned				1.76%	2.73%
Average Interest Rates for Funds Borrowed From and Loaned to Money Pool
Average Interest Rate For Funds Loaned				1.94%	2.87%
Southwestern Electric Power Co [Member] | Notes Payable, Other Payables [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				$ 1,600,000
Due Date				2032
Interest Rate (Percentage)				4.58%
Southwestern Electric Power Co [Member] | Loans Payable [Member]
Short-term Debt:
Weighted Average Interest Rate	[5]			2.98%		3.29%
Kentucky Power Co [Member] | Other Long Term Debt [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt	[3]			$ 125,000,000
Due Date				2022
Interest Rate (Variable)				Variable
Transource Energy [Member] | Other Long Term Debt [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt	[3]			$ 5,000,000
Due Date				2023
Interest Rate (Variable)				Variable
Transource Energy [Member] | Other Long Term Debt [Member] | Subsequent Event [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt			$ 1,000,000
Due Date			2023
Transource Energy [Member] | OtherLongTermDebtTwo [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt				$ 148,600,000
Due Date				2023
Interest Rate (Variable)				Varaible
Transource Energy [Member] | Senior Unsecured Notes [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Proceeds from Issuance of Debt	[3]			$ 150,000,000
Due Date				2050
Interest Rate (Percentage)				2.75%
Maximum [Member]
Financing Activities (Textuals)
AEP Share Price for Equity Unit Conversion				$ 99.58
Shares Per Equity Unit				0.6026
Minimum [Member]
Financing Activities (Textuals)
AEP Share Price for Equity Unit Conversion				$ 82.98
Shares Per Equity Unit				0.5021
Retained Earnings [Member]
Financing Activities (Textuals)
Stockholders' Equity, Other				$ 0	$ 62,100,000
Notes Payable, Other Payables [Member] | Indiana Michigan Power Co [Member] | Subsequent Event [Member]
Long-term Debt and Other Securities Issued, Retired and Principal Payments Made
Repayments of Long-term Debt		$ 1,000,000	$ 8,000,000
[1]	Pursuant to the Nuclear Waste Policy Act of 1982, I&M, a nuclear licensee, has an obligation to the United States Department of Energy for SNF disposal. The obligation includes a one-time fee for nuclear fuel consumed prior to April 7, 1983. Trust fund assets related to this obligation were $324 million and $323 million as of March 31, 2020 and December 31, 2019 , respectively, and are included in Spent Nuclear Fuel and Decommissioning Trusts on the balance sheets.
[2]	See “Equity Units” section below for additional information.
[3]	Amounts indicated on the statements of cash flows are net of issuance costs and premium or discount and will not tie to the issuance amounts.
[4]	Amount of securitized debt for receivables as accounted for under the “Transfers and Servicing” accounting guidance.
[5]	Weighted-average rate.
[6]	Amount represents the combined authorized short-term borrowing limit the State Transcos have from FERC or state regulatory commissions.
[7]	Amount represents the combined authorized short-term borrowing limit the State Transcos have from FERC or state regulatory commissions.

Revenue from Contracts with C_3

Revenue from Contracts with Customers (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020		Mar. 31, 2019		Dec. 31, 2019
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		$ 3,747.5		$ 4,056.8
Revenue Not from Contract with Customer, Other		40.6		10.9
Total Revenues		3,747.5		4,056.8
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		1,287.5
Revenue Textuals [Abstract]
Revenue from Related Parties		0		0
2020 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		732.4
2021-2022 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		171.1
2023-2024 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		160.6
2024 and Forward [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		223.4
Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		2,870.2		3,102.8
Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		1,436.4		1,568.5
Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		766.3		822.1
Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		615.8		657.8
Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		51.7		54.4
Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		765.2		865
Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		184.5		294.7
Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		240.8	[1]	208.8	[2]
Renewable Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		16.6	[3]	7.8	[4]
Retail, Trading and Marketing Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		323.3	[5]	353.7	[6]
Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		71.5	[3]	78.1	[4]
Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		3,706.9		4,045.9
Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		20.7	[3]	(0.2)	[4]
Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		70.9		65
Revenue Not from Contract with Customer, Other		19.9	[3]	11.1	[4]
AEP Texas Inc. [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		29.5		38.9
Total Revenues		423.6		390.7
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		290.3
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		10.4				$ 10.1
Revenue Textuals [Abstract]
Revenue from Related Parties		31.1		40.2
AEP Texas Inc. [Member] | 2020 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		290.3
AEP Texas Inc. [Member] | 2021-2022 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0
AEP Texas Inc. [Member] | 2023-2024 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0
AEP Texas Inc. [Member] | 2024 and Forward [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0
AEP Texas Inc. [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		289.3		259.1
AEP Texas Inc. [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		132.9		120.9
AEP Texas Inc. [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		112.8		97.9
AEP Texas Inc. [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		35.2		33
AEP Texas Inc. [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		8.4		7.3
AEP Texas Inc. [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		96.9		85.8
AEP Texas Inc. [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0	[7]	0	[8]
AEP Texas Inc. [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		96.9	[9]	85.8	[10]
AEP Texas Inc. [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		7.9	[11]	6.9	[12]
AEP Texas Inc. [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		394.1		351.8
AEP Texas Inc. [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(0.7)	[13]	(0.9)	[14]
AEP Texas Inc. [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.9		0.7
Revenue Not from Contract with Customer, Other		30.2	[13]	39.8	[14]
AEP Transmission Co [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(6)		(1.7)
Total Revenues		295.6		243.5
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		821.5
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		87.8				66.1
Revenue Textuals [Abstract]
Revenue from Related Parties		233.7		193.2
AEP Transmission Co [Member] | Short-term Contract with Customer [Member]
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		80.6				65.9
AEP Transmission Co [Member] | 2020 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		821.5
AEP Transmission Co [Member] | 2021-2022 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0
AEP Transmission Co [Member] | 2023-2024 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0
AEP Transmission Co [Member] | 2024 and Forward [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0
AEP Transmission Co [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
AEP Transmission Co [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
AEP Transmission Co [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
AEP Transmission Co [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
AEP Transmission Co [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
AEP Transmission Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		298.2		242.1
AEP Transmission Co [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0	[7]	0	[8]
AEP Transmission Co [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		298.2	[9]	242.1	[10]
Revenue Textuals [Abstract]
Revenue from Related Parties		235		195
AEP Transmission Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		3.4	[11]	3.1	[12]
AEP Transmission Co [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		301.6		245.2
AEP Transmission Co [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(6)	[13]	(1.7)	[14]
AEP Transmission Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.6		0
Revenue Not from Contract with Customer, Other		0	[13]	0	[14]
Appalachian Power Co [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(1.1)		4.4
Total Revenues		749.4		792.8
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		186.9
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		78				64.3
Revenue Textuals [Abstract]
Revenue from Related Parties		49.7		51.7
Appalachian Power Co [Member] | Short-term Contract with Customer [Member]
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		56.3				47.3
Appalachian Power Co [Member] | 2020 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		118.6
Appalachian Power Co [Member] | 2021-2022 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		32.3
Appalachian Power Co [Member] | 2023-2024 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		24.4
Appalachian Power Co [Member] | 2024 and Forward [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		11.6
Appalachian Power Co [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		648.8		681.8
Appalachian Power Co [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		357.5		372.5
Appalachian Power Co [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		132.3		142.2
Appalachian Power Co [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		141.1		147.5
Appalachian Power Co [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		17.9		19.6
Appalachian Power Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		84.5		93.2
Appalachian Power Co [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		54.1	[7]	67.5	[8]
Revenue Textuals [Abstract]
Revenue from Related Parties		33		35
Appalachian Power Co [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		30.4	[9]	25.7	[10]
Appalachian Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		17.2	[11]	13.4	[12]
Appalachian Power Co [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		750.5		788.4
Appalachian Power Co [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(1.1)	[13]	4.4	[14]
Appalachian Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		2.7		2.4
Revenue Not from Contract with Customer, Other		0	[13]	0	[14]
Indiana Michigan Power Co [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		0.4		(4.8)
Total Revenues		570.3		614.3
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		44.2
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		51.1				53.7
Revenue Textuals [Abstract]
Revenue from Related Parties		2.9		2.3
Indiana Michigan Power Co [Member] | Short-term Contract with Customer [Member]
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		37.4				37.1
Indiana Michigan Power Co [Member] | 2020 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		22.2
Indiana Michigan Power Co [Member] | 2021-2022 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		8.8
Indiana Michigan Power Co [Member] | 2023-2024 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		8.8
Indiana Michigan Power Co [Member] | 2024 and Forward [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		4.4
Indiana Michigan Power Co [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		463.1		479.9
Indiana Michigan Power Co [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		201.3		218.4
Indiana Michigan Power Co [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		122.2		121.3
Indiana Michigan Power Co [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		137.8		138.4
Indiana Michigan Power Co [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		1.8		1.8
Indiana Michigan Power Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		85.8		118.2
Indiana Michigan Power Co [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		78.4	[7]	111.9	[8]
Indiana Michigan Power Co [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		7.4	[9]	6.3	[10]
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		21	[11]	21	[12]
Indiana Michigan Power Co [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		569.9		619.1
Indiana Michigan Power Co [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		0.4	[13]	(4.8)	[14]
Indiana Michigan Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		1.5		2
Revenue Not from Contract with Customer, Other		0	[13]	0	[14]
Revenue Textuals [Abstract]
Revenue from Related Parties		16		15
Ohio Power Co [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		26.1		8.7
Total Revenues		690.3		836.8
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		43.2
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		73.1				59.3
Revenue Textuals [Abstract]
Revenue from Related Parties		8.4		7.5
Ohio Power Co [Member] | Short-term Contract with Customer [Member]
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		39.3				33.9
Ohio Power Co [Member] | 2020 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		43.2
Ohio Power Co [Member] | 2021-2022 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0
Ohio Power Co [Member] | 2023-2024 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0
Ohio Power Co [Member] | 2024 and Forward [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0
Ohio Power Co [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		618.5		775.2
Ohio Power Co [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		388.4		471.6
Ohio Power Co [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		164		210.5
Ohio Power Co [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		62.7		89.7
Ohio Power Co [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		3.4		3.4
Ohio Power Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		17.1		13.9
Ohio Power Co [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0	[7]	0	[8]
Ohio Power Co [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		17.1	[9]	13.9	[10]
Ohio Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		28.6	[11]	39	[12]
Ohio Power Co [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		664.2		828.1
Ohio Power Co [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		20	[13]	3.6	[14]
Ohio Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		2.7		2.8
Revenue Not from Contract with Customer, Other		6.1	[13]	5.1	[14]
Public Service Co Of Oklahoma [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		0.4		(1.2)
Total Revenues		297.3		332.8
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		10.8
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		19.9				20.6
Revenue Textuals [Abstract]
Revenue from Related Parties		1.1		1.6
Public Service Co Of Oklahoma [Member] | Short-term Contract with Customer [Member]
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		6.2				9.7
Public Service Co Of Oklahoma [Member] | 2020 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		10.8
Public Service Co Of Oklahoma [Member] | 2021-2022 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0
Public Service Co Of Oklahoma [Member] | 2023-2024 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0
Public Service Co Of Oklahoma [Member] | 2024 and Forward [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0
Public Service Co Of Oklahoma [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		282.5		309.8
Public Service Co Of Oklahoma [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		128.5		140
Public Service Co Of Oklahoma [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		76.1		80.8
Public Service Co Of Oklahoma [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		61.3		71
Public Service Co Of Oklahoma [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		16.6		18
Public Service Co Of Oklahoma [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		9.7		18.4
Public Service Co Of Oklahoma [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		1.9	[7]	8.6	[8]
Public Service Co Of Oklahoma [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		7.8	[9]	9.8	[10]
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		4.7	[11]	5.8	[12]
Public Service Co Of Oklahoma [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		296.9		334
Public Service Co Of Oklahoma [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		0.4	[13]	(1.2)	[14]
Public Service Co Of Oklahoma [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.8		2
Revenue Not from Contract with Customer, Other		0	[13]	0	[14]
Southwestern Electric Power Co [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		1.6		(5.3)
Total Revenues		385.9		421.1
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		29.6
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		24.4				34.5
Revenue Textuals [Abstract]
Revenue from Related Parties		7.5		6.4
Southwestern Electric Power Co [Member] | Short-term Contract with Customer [Member]
Assets, Current [Abstract]
Affiliated Companies - Contracts with Customers		11				$ 17.6
Southwestern Electric Power Co [Member] | 2020 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		29.6
Southwestern Electric Power Co [Member] | 2021-2022 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0
Southwestern Electric Power Co [Member] | 2023-2024 [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0
Southwestern Electric Power Co [Member] | 2024 and Forward [Member]
Revenue, Performance Obligation [Abstract]
Fixed Performance Obligations		0
Southwestern Electric Power Co [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		319		337.2
Southwestern Electric Power Co [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		131.6		140.1
Southwestern Electric Power Co [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		105.6		113.7
Southwestern Electric Power Co [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		79.8		81.2
Southwestern Electric Power Co [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		2		2.2
Southwestern Electric Power Co [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		59.5		81.4
Southwestern Electric Power Co [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		34.1	[7]	57.2	[8]
Southwestern Electric Power Co [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		25.4	[9]	24.2	[10]
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		5.8	[11]	7.8	[12]
Southwestern Electric Power Co [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		384.3		426.4
Southwestern Electric Power Co [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		1.6	[13]	(5.3)	[14]
Southwestern Electric Power Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.8		0.4
Revenue Not from Contract with Customer, Other		0	[13]	0	[14]
Consolidation Eliminations [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
Revenue Not from Contract with Customer, Other		(21)		(39.7)
Total Revenues		(354.8)		(332.2)
Revenue Textuals [Abstract]
Revenue from Related Parties		(354.8)		(332.2)
Consolidation Eliminations [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(0.2)		1.8
Consolidation Eliminations [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
Consolidation Eliminations [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
Consolidation Eliminations [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(0.2)		1.8
Consolidation Eliminations [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
Consolidation Eliminations [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(293)		(258.2)
Consolidation Eliminations [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		(38.8)
Consolidation Eliminations [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(263)	[1]	(219.4)	[2]
Consolidation Eliminations [Member] | Renewable Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(0.6)	[3]	0	[4]
Consolidation Eliminations [Member] | Retail, Trading and Marketing Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(29.4)	[5]	0	[6]
Consolidation Eliminations [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(40.6)	[3]	(36.1)	[4]
Consolidation Eliminations [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(333.8)		(292.5)
Consolidation Eliminations [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		4.5	[3]	0	[4]
Consolidation Eliminations [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(25.5)	[3]	(39.7)	[4]
Consolidation Eliminations [Member] | AEP Transmission Co [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
Total Revenues		0		0
Revenue Textuals [Abstract]
Revenue from Related Parties		0		0
Consolidation Eliminations [Member] | AEP Transmission Co [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0
Vertically Integrated Utilities [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		0.2		(3.4)
Total Revenues		2,226.7		2,403.3
Revenue Textuals [Abstract]
Revenue from Related Parties		33.7		31
Vertically Integrated Utilities [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		1,962.6		2,069
Vertically Integrated Utilities [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		915.1		982.4
Vertically Integrated Utilities [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		489.4		511.2
Vertically Integrated Utilities [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		518.2		532.1
Vertically Integrated Utilities [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		39.9		43.3
Vertically Integrated Utilities [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		220.3		298.2
Vertically Integrated Utilities [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		140.4		224.7
Vertically Integrated Utilities [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		79.9	[1]	73.5	[2]
Vertically Integrated Utilities [Member] | Renewable Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0	[3]	0	[4]
Vertically Integrated Utilities [Member] | Retail, Trading and Marketing Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0	[5]	0	[6]
Vertically Integrated Utilities [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		43.6	[3]	39.5	[4]
Vertically Integrated Utilities [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		2,226.5		2,406.7
Vertically Integrated Utilities [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		0.2	[3]	(3.4)	[4]
Vertically Integrated Utilities [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		0	[3]	0	[4]
Transmission And Distribution Utilities [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		48.6		44.4
Total Revenues		1,106.9		1,222
Revenue Textuals [Abstract]
Revenue from Related Parties		31.7		42.2
Transmission And Distribution Utilities [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		907.8		1,032
Transmission And Distribution Utilities [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		521.3		586.1
Transmission And Distribution Utilities [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		276.9		310.9
Transmission And Distribution Utilities [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		97.8		123.9
Transmission And Distribution Utilities [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		11.8		11.1
Transmission And Distribution Utilities [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		114.1		99.6
Transmission And Distribution Utilities [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
Transmission And Distribution Utilities [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		114.1	[1]	99.6	[2]
Transmission And Distribution Utilities [Member] | Renewable Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0	[3]	0	[4]
Transmission And Distribution Utilities [Member] | Retail, Trading and Marketing Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0	[5]	0	[6]
Transmission And Distribution Utilities [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		36.4	[3]	46	[4]
Transmission And Distribution Utilities [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		1,058.3		1,177.6
Transmission And Distribution Utilities [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		19.3	[3]	5	[4]
Transmission And Distribution Utilities [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		29.3	[3]	39.4	[4]
AEP Transmission Holdco [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(3.3)		(1.8)
Total Revenues		310.2		256.4
AEP Transmission Holdco [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
AEP Transmission Holdco [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
AEP Transmission Holdco [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
AEP Transmission Holdco [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
AEP Transmission Holdco [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
AEP Transmission Holdco [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		309.8		255.1
AEP Transmission Holdco [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
AEP Transmission Holdco [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		309.8	[1]	255.1	[2]
Revenue Textuals [Abstract]
Revenue from Related Parties		239		198
AEP Transmission Holdco [Member] | Renewable Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0	[3]	0	[4]
AEP Transmission Holdco [Member] | Retail, Trading and Marketing Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0	[5]	0	[6]
AEP Transmission Holdco [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		3.7	[3]	3.1	[4]
AEP Transmission Holdco [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		313.5		258.2
AEP Transmission Holdco [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(3.3)	[3]	(1.8)	[4]
AEP Transmission Holdco [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		0	[3]	0	[4]
Generation And Marketing [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		18.3		9.2
Total Revenues		438.6		481.8
Revenue Textuals [Abstract]
Revenue from Related Parties		30.2		42.1
Generation And Marketing [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
Generation And Marketing [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
Generation And Marketing [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
Generation And Marketing [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
Generation And Marketing [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
Generation And Marketing [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		420		470.3
Generation And Marketing [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		44.1		108.8
Generation And Marketing [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0	[1]	0	[2]
Generation And Marketing [Member] | Wholesale Generation [Member]
Revenue Textuals [Abstract]
Revenue from Related Parties		35		37
Generation And Marketing [Member] | Renewable Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		17.2	[3]	7.8	[4]
Generation And Marketing [Member] | Retail, Trading and Marketing Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		358.7	[5]	353.7	[6]
Generation And Marketing [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0.3	[3]	2.3	[4]
Generation And Marketing [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		420.3		472.6
Generation And Marketing [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		0	[3]	0	[4]
Generation And Marketing [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		18.3	[3]	9.2	[4]
Other Segments [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		(2.2)		2.2
Total Revenues	[15]	19.9		25.5
Revenue Textuals [Abstract]
Revenue from Related Parties	[15]	22.1		21.7
Other Segments [Member] | Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
Other Segments [Member] | Residential [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
Other Segments [Member] | Commercial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
Other Segments [Member] | Industrial [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
Other Segments [Member] | Other Retail [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
Other Segments [Member] | Wholesale and Competitive [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(6)		0
Other Segments [Member] | Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0		0
Other Segments [Member] | Transmission [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0	[1]	0	[2]
Other Segments [Member] | Renewable Generation [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		0	[3]	0	[4]
Other Segments [Member] | Retail, Trading and Marketing Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		(6)	[5]	0	[6]
Other Segments [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		28.1	[3]	23.3	[4]
Other Segments [Member] | Affiliated and Nonaffiliated [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers		22.1		23.3
Other Segments [Member] | Alternative [Member]
Disaggregation of Revenue [Abstract]
Revenue Not from Contract with Customer, Other		0	[3]	0	[4]
Other Segments [Member] | Other Revenues [Member]
Disaggregation of Revenue [Abstract]
Revenue from Contracts with Customers	[15]	(2.2)		3.8
Revenue Not from Contract with Customer, Other		$ (2.2)	[3]	$ 2.2	[4]
[1]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $239 million . The remaining affiliated amounts were immaterial.
[2]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEP Transmission Holdco was $198 million . The remaining affiliated amounts were immaterial.
[3]	Amounts include affiliated and nonaffiliated revenues.
[4]	Amounts include affiliated and nonaffiliated revenues.
[5]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $35 million . The remaining affiliated amounts were immaterial.
[6]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for Generation & Marketing was $37 million . The remaining affiliated amounts were immaterial.
[7]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $33 million primarily relating to the PPA with KGPCo. The remaining affiliated amounts were immaterial.
[8]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for APCo was $35 million primarily relating to the PPA with KGPCo. The remaining affiliated amounts were immaterial.
[9]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEPTCo was $235 million . The remaining affiliated amounts were immaterial.
[10]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for AEPTCo was $195 million . The remaining affiliated amounts were immaterial.
[11]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $16 million primarily relating to the barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial.
[12]	Amounts include affiliated and nonaffiliated revenues. The affiliated revenue for I&M was $15 million primarily relating to the barging, urea transloading and other transportation services. The remaining affiliated amounts were immaterial.
[13]	Amounts include affiliated and nonaffiliated revenues.
[14]	Amounts include affiliated and nonaffiliated revenues.
[15]	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.