Condensed Consolidated Statements of Changes in Equity - USD ($)	Total	Vertically Integrated Utilities [Member]	Transmission and Distribution Utilities [Member]	Generation and Marketing Revenues [Member]	Other Revenues [Member]		Reconciling Adjustments [Member]	Reconciling Adjustments [Member] Other Revenues [Member]		Generation And Marketing [Member]	Generation And Marketing [Member] Generation and Marketing Revenues [Member]	Generation And Marketing [Member] Other Revenues [Member]		Other Operating Segment [Member]	[2]	Other Operating Segment [Member] Other Revenues [Member]		Transmission Operations [Member]	Transmission Operations [Member] Transmission [Member]	Transmission And Distribution Utilities [Member]	Transmission And Distribution Utilities [Member] Transmission and Distribution Utilities [Member]	Transmission And Distribution Utilities [Member] Other Revenues [Member]		Vertically Integrated Utilities [Member]	Vertically Integrated Utilities [Member] Vertically Integrated Utilities [Member]	Vertically Integrated Utilities [Member] Other Revenues [Member]		Appalachian Power Co [Member]	Appalachian Power Co [Member] Vertically Integrated Utilities [Member]	Appalachian Power Co [Member] Other Revenues [Member]		AEP Texas Inc. [Member]	AEP Texas Inc. [Member] Transmission and Distribution Utilities [Member]	AEP Texas Inc. [Member] Other Revenues [Member]		AEP Transmission Co [Member]	AEP Transmission Co [Member] Transmission [Member]	AEP Transmission Co [Member] Other Revenues [Member]		AEP Transmission Co [Member] Reconciling Adjustments [Member]	AEP Transmission Co [Member] Reconciling Adjustments [Member] Other Revenues [Member]	AEP Transmission Co [Member] State Transcos [Member]	AEP Transmission Co [Member] State Transcos [Member] Transmission [Member]	AEP Transmission Co [Member] State Transcos [Member] Other Revenues [Member]	AEP Transmission Co [Member] AEPTCo Parent [Member]		AEP Transmission Co [Member] AEPTCo Parent [Member] Other Revenues [Member]	Indiana Michigan Power Co [Member]	Indiana Michigan Power Co [Member] Vertically Integrated Utilities [Member]	Indiana Michigan Power Co [Member] Other Revenues [Member]		Ohio Power Co [Member]	Ohio Power Co [Member] Transmission and Distribution Utilities [Member]	Ohio Power Co [Member] Other Revenues [Member]		Public Service Co Of Oklahoma [Member]	Public Service Co Of Oklahoma [Member] Vertically Integrated Utilities [Member]	Public Service Co Of Oklahoma [Member] Other Revenues [Member]		Southwestern Electric Power Co [Member]	Southwestern Electric Power Co [Member] Vertically Integrated Utilities [Member]	Southwestern Electric Power Co [Member] Other Revenues [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 (Loss) [Member]	Accumulated Other Comprehensive Income (Loss) [Member] Appalachian Power Co [Member]	Accumulated Other Comprehensive Income (Loss) [Member] AEP Texas Inc. [Member]	Accumulated Other Comprehensive Income (Loss) [Member] Indiana Michigan Power Co [Member]	Accumulated Other Comprehensive Income (Loss) [Member] Public Service Co Of Oklahoma [Member]	Accumulated Other Comprehensive Income (Loss) [Member] Southwestern Electric Power Co [Member]	Noncontrolling Interests [Member]	Noncontrolling Interests [Member] Southwestern Electric Power Co [Member]	Competitive Contracted Renewable Portfolio	Competitive Contracted Renewable Portfolio Noncontrolling Interests [Member]
Beginning Balance at Dec. 31, 2022																																				$ 5,873,000,000																																					$ 3,022,300,000									$ 2,850,700,000
Beginning Balance at Dec. 31, 2022	$ 24,122,400,000																											$ 4,975,400,000				$ 3,904,300,000																$ 3,008,300,000				$ 3,088,100,000				$ 2,419,100,000				$ 3,674,800,000				$ 3,413,100,000	$ 260,400,000	$ 56,600,000	$ 321,200,000	$ 157,200,000	$ 100,000	$ 8,051,000,000	$ 1,828,700,000	$ 1,558,200,000		$ 988,800,000	$ 837,800,000	$ 1,042,600,000	$ 1,442,200,000	$ 12,345,600,000		$ 2,891,100,000	$ 2,354,700,000		$ 1,963,200,000	$ 1,929,100,000	$ 1,218,000,000	$ 2,236,000,000	$ 83,700,000	$ (4,800,000)	$ (8,600,000)	$ (300,000)	$ 1,300,000	$ (4,200,000)	$ 229,000,000.0	$ 700,000
Beginning Balance, Shares at Dec. 31, 2022																																																																525,100,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock, Value	41,100,000																																																															$ 5,100,000						36,000,000.0
Issuance of Common Stock, Shares																																																																800,000
Common Stock Dividends	(431,800,000)																																																																													(428,800,000)	[1]
Common Stock Dividends																																																(31,200,000)								(17,500,000)																											(31,200,000)		(17,500,000)
Common Stock Dividends																																																												(1,500,000)																																	(3,000,000.0)	(1,500,000)
Other Changes in Equity	(12,500,000)																																																																					(12,700,000)																							200,000
Capital Contribution from Parent/Member																																100,000,000.0				25,000,000.0																								50,000,000.0												100,000,000.0	25,000,000.0				50,000,000.0
Capital Contributions from Parent																																																				50,000,000.0																							50,000,000.0
Dividends Paid on Common Stock																																				(55,000,000.0)																																														(55,000,000.0)
Net Income (Loss)																																																																														397,000,000.0								40,600,000
Net Income (Loss) Attributable to Noncontrolling Interests																																																																																													3,400,000	1,200,000
Net Income (Loss)	400,400,000																											112,500,000				47,600,000				162,700,000												102,800,000				78,000,000.0				(2,300,000)				41,800,000																				112,500,000	47,600,000	162,700,000	102,800,000	78,000,000.0	(2,300,000)
Other Comprehensive Income (Loss)	(151,800,000)																											(1,000,000.0)				(600,000)																(2,600,000)								(1,500,000)				100,000																											(151,800,000)	(1,000,000.0)	(600,000)	(2,600,000)	(1,500,000)	100,000
Ending Balance at Mar. 31, 2023																																				6,005,700,000																																					3,047,300,000									2,958,400,000
Ending Balance at Mar. 31, 2023	$ 23,967,800,000																											5,086,900,000				4,051,300,000																3,077,300,000				3,216,100,000				2,397,800,000				3,765,200,000				$ 3,418,200,000	260,400,000	56,600,000	321,200,000	157,200,000	100,000	8,074,300,000	1,828,700,000	1,658,200,000		988,800,000	887,800,000	1,042,600,000	1,492,200,000	12,313,800,000		3,003,600,000	2,402,300,000		2,034,800,000	2,007,100,000	1,198,200,000	2,276,600,000	(68,100,000)	(5,800,000)	(9,200,000)	(2,900,000)	(200,000)	(4,100,000)	229,600,000	400,000
Ending Balance, Shares at Mar. 31, 2023																																																																525,900,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends Per Share, Declared	$ 0.83
Beginning Balance at Dec. 31, 2022																																				5,873,000,000																																					3,022,300,000									2,850,700,000
Beginning Balance at Dec. 31, 2022	$ 24,122,400,000																											4,975,400,000				3,904,300,000																3,008,300,000				3,088,100,000				2,419,100,000				3,674,800,000				$ 3,413,100,000	260,400,000	56,600,000	321,200,000	157,200,000	100,000	8,051,000,000	1,828,700,000	1,558,200,000		988,800,000	837,800,000	1,042,600,000	1,442,200,000	12,345,600,000		2,891,100,000	2,354,700,000		1,963,200,000	1,929,100,000	1,218,000,000	2,236,000,000	83,700,000	(4,800,000)	(8,600,000)	(300,000)	1,300,000	(4,200,000)	229,000,000.0	700,000
Beginning Balance, Shares at Dec. 31, 2022																																																																525,100,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital Contributions from Parent																												6,500,000				525,800,000				27,900,000												1,700,000				175,000,000.0				600,000				50,000,000.0
Dividends Paid on Common Stock																												0				0				(115,000,000.0)												(137,500,000)								(35,000,000.0)				(125,000,000.0)
Net Income (Loss)	1,871,900,000																																																											279,100,000
Net Income (Loss) Attributable to Noncontrolling Interests	2,900,000																																																											3,000,000.0
Net Income (Loss)	1,874,800,000						$ 0			$ (62,200,000)				$ (209,600,000)				$ 583,600,000		$ 508,400,000				$ 1,054,600,000				247,300,000				282,200,000				517,600,000				$ 0		$ 514,000,000.0			$ 3,600,000	[3]		270,600,000				226,200,000				188,100,000				282,100,000
Other Comprehensive Income (Loss)	(124,200,000)																											(2,900,000)				2,500,000																(2,900,000)												(700,000)
Ending Balance at Sep. 30, 2023																																				6,294,900,000																																					3,041,600,000									3,253,300,000
Ending Balance at Sep. 30, 2023	25,349,600,000																											5,226,300,000				4,710,500,000																3,140,200,000				3,489,300,000				2,568,800,000				3,878,800,000				$ 3,424,300,000	260,400,000	56,600,000	321,200,000	157,200,000	100,000	8,996,400,000	1,835,200,000	2,079,700,000		990,500,000	1,012,800,000	1,040,700,000	1,492,200,000	12,929,500,000		3,138,400,000	2,636,900,000		2,096,300,000	2,155,300,000	1,371,100,000	2,390,100,000	(40,500,000)	(7,700,000)	(6,100,000)	(3,200,000)	(200,000)	(4,900,000)	39,900,000	1,300,000
Ending Balance, Shares at Sep. 30, 2023																																																																526,800,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Revenue from Contracts with Customers	14,405,100,000	$ 8,603,400,000	$ 4,321,300,000	$ 1,172,600,000	$ 307,800,000		0				$ 1,172,600,000					$ 35,400,000	[2]		$ 272,400,000		$ 4,321,300,000				$ 8,603,400,000				$ 2,573,000,000	$ 9,800,000			$ 1,438,700,000	$ 2,900,000			$ 274,000,000.0	$ 0		0			$ 269,200,000		0				$ 1,879,300,000	$ 9,700,000			$ 2,869,300,000	$ 10,300,000			$ 1,529,800,000	$ 5,100,000			$ 1,665,200,000	$ 1,800,000
Revenues	14,405,100,000				(250,200,000)	[4],[5]	(1,416,300,000)	$ (3,600,000)	[4],[5]	1,225,100,000		$ (272,800,000)	[4],[5]	119,300,000		4,000,000.0	[4],[5]	1,390,800,000		4,348,500,000		$ 20,000,000.0	[4],[5]	8,737,700,000		$ 2,200,000	[4],[5]	2,776,000,000		100,000	[6]	1,445,300,000		0	[6]	1,349,200,000		0	[6]	0		1,349,200,000			0			1,938,500,000		2,100,000	[6]	2,903,200,000		20,100,000	[6]	1,535,900,000		0	[6]	1,708,500,000		0	[6]
Revenues from Related Parties, Net of Provisions for Refund																																				1,080,000,000
Revenue from Contract with Customers, Net of Provisions for Refund, Including Assessed Tax																																					269,200,000
Beginning Balance at Mar. 31, 2023																																				6,005,700,000																																					3,047,300,000									2,958,400,000
Beginning Balance at Mar. 31, 2023	23,967,800,000																											5,086,900,000				4,051,300,000																3,077,300,000				3,216,100,000				2,397,800,000				3,765,200,000				$ 3,418,200,000	260,400,000	56,600,000	321,200,000	157,200,000	100,000	8,074,300,000	1,828,700,000	1,658,200,000		988,800,000	887,800,000	1,042,600,000	1,492,200,000	12,313,800,000		3,003,600,000	2,402,300,000		2,034,800,000	2,007,100,000	1,198,200,000	2,276,600,000	(68,100,000)	(5,800,000)	(9,200,000)	(2,900,000)	(200,000)	(4,100,000)	229,600,000	400,000
Beginning Balance, Shares at Mar. 31, 2023																																																																525,900,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock, Value	36,500,000																																																															$ 3,300,000						33,200,000
Issuance of Common Stock, Shares																																																																500,000
Common Stock Dividends	(431,800,000)																																																																													(429,500,000)	[1]
Common Stock Dividends																																																(31,300,000)												(50,000,000.0)																							(31,300,000)			(50,000,000.0)
Common Stock Dividends																																																												(600,000)																																	(2,300,000)	(600,000)
Other Changes in Equity	3,300,000																																																																					3,300,000
Capital Contribution from Parent/Member																																175,300,000																100,000																								175,300,000		100,000
Capital Contributions from Parent																												4,300,000																								125,000,000.0																			4,300,000				125,000,000.0
Return of Capital to Parent																																(4,300,000)				(8,600,000)																				(2,500,000)																(4,300,000)	(8,600,000)			(2,500,000)
Dividends Paid on Common Stock																																				(30,000,000.0)																																														(30,000,000.0)
Net Income (Loss)																																																																														521,200,000								81,000,000.0
Net Income (Loss) Attributable to Noncontrolling Interests																																																																																													(5,100,000)	300,000
Net Income (Loss)	516,100,000																											42,900,000				109,100,000				175,700,000												74,800,000				67,700,000				51,000,000.0				81,300,000																				42,900,000	109,100,000	175,700,000	74,800,000	67,700,000	51,000,000.0
Other Comprehensive Income (Loss)	31,700,000																											(1,000,000.0)				3,200,000																(200,000)												(400,000)																											31,700,000	(1,000,000.0)	3,200,000	(200,000)		(400,000)
Ending Balance at Jun. 30, 2023																																				6,142,800,000																																					3,038,700,000									3,104,100,000
Ending Balance at Jun. 30, 2023	$ 24,123,600,000																											5,133,100,000				4,334,600,000																3,120,700,000				3,408,800,000				2,446,300,000				3,795,500,000				$ 3,421,500,000	260,400,000	56,600,000	321,200,000	157,200,000	100,000	8,110,800,000	1,833,000,000	1,829,200,000		988,900,000	1,012,800,000	1,040,100,000	1,492,200,000	12,405,500,000		3,046,500,000	2,511,400,000		2,078,300,000	2,074,800,000	1,249,200,000	2,307,600,000	(36,400,000)	(6,800,000)	(6,000,000.0)	(3,100,000)	(200,000)	(4,500,000)	222,200,000	100,000
Ending Balance, Shares at Jun. 30, 2023																																																																526,400,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends Per Share, Declared	$ 0.83
Issuance of Common Stock, Value	$ 881,700,000																																																															$ 2,800,000						878,900,000
Issuance of Common Stock, Shares																																																																400,000
Common Stock Dividends	(430,200,000)																																																							(17,500,000)																						(429,700,000)	[1]						(17,500,000)
Common Stock Dividends																																																(75,000,000.0)												(75,000,000.0)																							(75,000,000.0)			(75,000,000.0)
Common Stock Dividends																																																												(300,000)																																	(500,000)	(300,000)
Other Changes in Equity	6,700,000																																																																					6,700,000
Capital Contribution from Parent/Member																																250,500,000				2,900,000												1,600,000																								250,500,000	2,900,000	1,600,000
Capital Contributions from Parent																												2,200,000																												600,000															2,200,000					600,000
Dividends Paid on Common Stock																																				(30,000,000.0)																																														(30,000,000.0)
Gain (Loss) on Disposition of Assets																																																																																															$ (186,400,000)	$ (186,400,000)
Net Income (Loss)	953,700,000																																																											157,500,000																		953,700,000								157,500,000
Net Income (Loss) Attributable to Noncontrolling Interests	4,600,000																																																											1,500,000																																	4,600,000	1,500,000
Net Income (Loss)	958,300,000						0			132,800,000				(98,400,000)				203,900,000		206,000,000.0				514,000,000.0				91,900,000				125,500,000				179,200,000				0		178,200,000			1,000,000.0	[3]		93,000,000.0				80,500,000				139,400,000				159,000,000.0																				91,900,000	125,500,000	179,200,000	93,000,000.0	80,500,000	139,400,000
Other Comprehensive Income (Loss)	(4,100,000)																											(900,000)				(100,000)																(100,000)												(400,000)																											(4,100,000)	(900,000)	(100,000)	(100,000)		(400,000)
Ending Balance at Sep. 30, 2023																																				6,294,900,000																																					3,041,600,000									3,253,300,000
Ending Balance at Sep. 30, 2023	$ 25,349,600,000																											5,226,300,000				4,710,500,000																3,140,200,000				3,489,300,000				2,568,800,000				3,878,800,000				$ 3,424,300,000	260,400,000	56,600,000	321,200,000	157,200,000	100,000	8,996,400,000	1,835,200,000	2,079,700,000		990,500,000	1,012,800,000	1,040,700,000	1,492,200,000	12,929,500,000		3,138,400,000	2,636,900,000		2,096,300,000	2,155,300,000	1,371,100,000	2,390,100,000	(40,500,000)	(7,700,000)	(6,100,000)	(3,200,000)	(200,000)	(4,900,000)	39,900,000	1,300,000
Ending Balance, Shares at Sep. 30, 2023																																																																526,800,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends Per Share, Declared	$ 0.83
Revenue from Contracts with Customers	$ 5,341,700,000	3,158,100,000	1,535,200,000	527,500,000	120,900,000		0				527,500,000					26,900,000	[2]		94,000,000.0		1,535,200,000				3,158,100,000				896,000,000.0	3,300,000			551,600,000	1,800,000			93,800,000	0		0			92,800,000		0				656,100,000	4,200,000			978,700,000	3,000,000.0			642,600,000	1,400,000			640,000,000.0	500,000
Revenues	5,341,700,000				8,500,000	[7],[8]	(508,400,000)	(700,000)	[7],[8]	566,700,000		3,400,000	[7],[8]	57,200,000		800,000	[7],[8]	476,700,000		1,544,100,000		2,800,000	[7],[8]	3,205,400,000		2,200,000	[7],[8]	961,800,000		100,000	[9]	554,600,000		0	[9]	462,700,000		0	[9]	0		462,700,000			0			676,300,000		2,100,000	[9]	989,500,000		3,000,000.0	[9]	644,200,000		0	[9]	654,800,000		0	[9]
Revenues from Related Parties, Net of Provisions for Refund																																				369,900,000
Revenue from Contract with Customers, Net of Provisions for Refund, Including Assessed Tax																																					92,800,000
Beginning Balance at Dec. 31, 2023																																				6,333,300,000																																					3,043,400,000									3,289,900,000
Beginning Balance at Dec. 31, 2023	$ 25,285,900,000																											5,276,700,000				4,796,100,000																3,140,200,000				3,571,300,000				$ 2,570,600,000				3,770,400,000				$ 3,427,900,000	260,400,000	56,600,000	321,200,000	157,200,000	100,000	9,073,900,000	1,834,500,000	2,079,600,000		997,600,000	1,012,800,000	1,039,300,000	1,492,200,000	12,800,400,000		3,185,500,000	2,725,100,000		2,086,600,000	2,237,300,000	1,374,300,000	2,281,300,000	(55,500,000)	(3,700,000)	(8,600,000)	(600,000)	(200,000)	(3,400,000)	39,200,000	200,000
Beginning Balance, Shares at Dec. 31, 2023	527,369,157																																																							10,482,000								527,400,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock, Value	$ 40,600,000																																																															$ 5,400,000						35,200,000
Issuance of Common Stock, Shares																																																																800,000
Common Stock Dividends	(466,900,000)																																																																													(465,500,000)	[10]
Common Stock Dividends																																																(37,500,000)								$ (35,000,000.0)				(50,000,000.0)																							(37,500,000)		(35,000,000.0)	(50,000,000.0)
Common Stock Dividends																																																												(1,400,000)																																	(1,400,000)	(1,400,000)
Other Changes in Equity	(14,800,000)																																																																					(14,800,000)
Capital Contribution from Parent/Member																																				25,000,000.0																																					25,000,000.0
Capital Contributions from Parent																												100,000,000.0																																											100,000,000.0
Dividends Paid on Common Stock																																				(40,000,000.0)																																														(40,000,000.0)
Net Income (Loss)																																																																														1,003,100,000								208,100,000
Net Income (Loss) Attributable to Noncontrolling Interests																																																																																													2,600,000	1,500,000
Net Income (Loss)	1,005,700,000																											136,500,000				79,700,000				181,200,000												145,000,000.0				70,600,000				72,000,000.0				209,600,000																				136,500,000	79,700,000	181,200,000	145,000,000.0	70,600,000	72,000,000.0
Other Comprehensive Income (Loss)	(6,800,000)																											(500,000)				3,900,000																100,000												(200,000)																											(6,800,000)	(500,000)	3,900,000	100,000		(200,000)
Ending Balance at Mar. 31, 2024																																				6,499,500,000																																					3,068,400,000									3,431,100,000
Ending Balance at Mar. 31, 2024	$ 25,843,700,000																											5,512,700,000				4,879,700,000																3,247,800,000				3,641,900,000				2,607,600,000				3,928,400,000				$ 3,433,300,000	260,400,000	56,600,000	321,200,000	157,200,000	100,000	9,094,300,000	1,934,500,000	2,079,600,000		997,600,000	1,012,800,000	1,039,300,000	1,492,200,000	13,338,000,000		3,322,000,000	2,804,800,000		2,194,100,000	2,307,900,000	1,411,300,000	2,439,400,000	(62,300,000)	(4,200,000)	(4,700,000)	(500,000)	(200,000)	(3,600,000)	40,400,000	300,000
Ending Balance, Shares at Mar. 31, 2024																																																																528,200,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends Per Share, Declared	$ 0.88
Beginning Balance at Dec. 31, 2023																																				6,333,300,000																																					3,043,400,000									3,289,900,000
Beginning Balance at Dec. 31, 2023	$ 25,285,900,000																											5,276,700,000				4,796,100,000																3,140,200,000				3,571,300,000				$ 2,570,600,000				3,770,400,000				$ 3,427,900,000	260,400,000	56,600,000	321,200,000	157,200,000	100,000	9,073,900,000	1,834,500,000	2,079,600,000		997,600,000	1,012,800,000	1,039,300,000	1,492,200,000	12,800,400,000		3,185,500,000	2,725,100,000		2,086,600,000	2,237,300,000	1,374,300,000	2,281,300,000	(55,500,000)	(3,700,000)	(8,600,000)	(600,000)	(200,000)	(3,400,000)	39,200,000	200,000
Beginning Balance, Shares at Dec. 31, 2023	527,369,157																																																							10,482,000								527,400,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock, Shares	4,437,136
Capital Contributions from Parent																												109,500,000				1,600,000				34,600,000												5,000,000.0				800,000				$ 200,000				0
Dividends Paid on Common Stock																												(75,000,000.0)				(150,000,000.0)				(97,000,000.0)												(112,500,000)								(105,000,000.0)				(250,000,000.0)
Net Income (Loss)	$ 2,303,000,000																																																											277,100,000
Net Income (Loss) Attributable to Noncontrolling Interests	6,900,000																																																											3,500,000
Net Income (Loss)	2,309,900,000						0			226,100,000				(287,500,000)				627,500,000		542,300,000				1,201,500,000				304,600,000				340,600,000				548,200,000				0		547,700,000			500,000	[3]		359,300,000				201,700,000				222,000,000.0				280,600,000
Other Comprehensive Income (Loss)	(31,400,000)																											(1,400,000)				6,000,000.0																200,000												(400,000)
Ending Balance at Sep. 30, 2024																																				6,814,600,000																																					3,073,500,000									3,741,100,000
Ending Balance at Sep. 30, 2024	$ 26,658,800,000																											5,609,900,000				4,993,600,000																3,390,400,000				3,773,800,000				$ 2,679,200,000				3,796,100,000				$ 3,468,700,000	260,400,000	56,600,000	321,200,000	157,200,000	100,000	9,534,900,000	1,939,500,000	2,080,500,000		1,000,800,000	1,013,600,000	1,039,500,000	1,491,100,000	13,700,700,000		3,415,100,000	2,915,700,000		2,333,400,000	2,439,000,000	1,491,300,000	2,308,400,000	(86,900,000)	(5,100,000)	(2,600,000)	(400,000)	(8,800,000)	(3,800,000)	41,400,000	300,000
Ending Balance, Shares at Sep. 30, 2024	533,652,728																																																							10,482,000								533,700,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Revenue from Contracts with Customers	$ 15,025,000,000	8,722,000,000	4,480,500,000	1,442,100,000	380,400,000		0				1,442,100,000					48,100,000	[2]		332,300,000		4,480,500,000				8,722,000,000				2,836,600,000	12,400,000			1,569,900,000	3,300,000			299,000,000.0	3,000,000.0		0	$ 0		295,100,000	$ 3,000,000.0	0		$ 0		1,932,300,000	7,000,000.0			2,899,000,000	8,300,000			1,439,100,000	17,200,000			1,680,500,000	7,000,000.0
Revenues	15,025,000,000				(166,400,000)	[11],[12]	(1,524,800,000)	4,900,000	[11],[12]	1,530,100,000		(158,900,000)	[11],[12]	148,600,000		(5,200,000)	[11],[12]	1,499,700,000		4,501,500,000		15,200,000	[11],[12]	8,869,900,000		(22,400,000)	[11],[12]	3,032,100,000		200,000	[13]	1,577,200,000		0	[13]	1,455,200,000		0	[13]	0		1,455,200,000			0			1,995,200,000		(22,700,000)	[13]	2,924,300,000		15,200,000	[13]	$ 1,462,000,000		0	[13]	1,550,800,000		0	[13]
Revenues from Related Parties, Net of Provisions for Refund																																				1,157,100,000
Revenue from Contract with Customers, Net of Provisions for Refund, Including Assessed Tax																																					295,100,000	3,000,000.0
Beginning Balance at Mar. 31, 2024																																				6,499,500,000																																					3,068,400,000									3,431,100,000
Beginning Balance at Mar. 31, 2024	25,843,700,000																											5,512,700,000				4,879,700,000																3,247,800,000				3,641,900,000				2,607,600,000				3,928,400,000				$ 3,433,300,000	260,400,000	56,600,000	321,200,000	157,200,000	100,000	9,094,300,000	1,934,500,000	2,079,600,000		997,600,000	1,012,800,000	1,039,300,000	1,492,200,000	13,338,000,000		3,322,000,000	2,804,800,000		2,194,100,000	2,307,900,000	1,411,300,000	2,439,400,000	(62,300,000)	(4,200,000)	(4,700,000)	(500,000)	(200,000)	(3,600,000)	40,400,000	300,000
Beginning Balance, Shares at Mar. 31, 2024																																																																528,200,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock, Value	435,200,000																																																															$ 32,100,000						403,100,000
Issuance of Common Stock, Shares																																																																4,900,000
Common Stock Dividends	(469,100,000)																																																																													(467,000,000.0)	[10]
Common Stock Dividends																																																(37,500,000)								(35,000,000.0)				(100,000,000.0)																							(37,500,000)		(35,000,000.0)	(100,000,000.0)
Common Stock Dividends																																																												(1,000,000.0)																																	(2,100,000)	(1,000,000.0)
Other Changes in Equity	1,100,000																																																																					1,100,000
Capital Contribution from Parent/Member																																1,600,000				9,600,000												5,000,000.0																								1,600,000	9,600,000	5,000,000.0
Capital Contributions from Parent																												9,500,000																												200,000															9,500,000					200,000
Dividends Paid on Common Stock																																				(31,000,000.0)																																														(31,000,000.0)
Net Income (Loss)																																																																														340,300,000								(70,100,000)
Net Income (Loss) Attributable to Noncontrolling Interests																																																																																													2,200,000	1,000,000.0
Net Income (Loss)	342,500,000																											58,300,000				128,400,000				175,700,000												35,200,000				18,400,000				36,300,000				(69,100,000)																				58,300,000	128,400,000	175,700,000	35,200,000	18,400,000	36,300,000
Other Comprehensive Income (Loss)	22,300,000																											(500,000)				2,200,000																																																							22,300,000	(500,000)	2,200,000
Ending Balance at Jun. 30, 2024																																				6,653,800,000																																					3,078,000,000									3,575,800,000
Ending Balance at Jun. 30, 2024	$ 26,175,700,000																											5,580,000,000				5,011,900,000																3,250,500,000				3,660,300,000				2,609,100,000				3,758,300,000				$ 3,465,400,000	260,400,000	56,600,000	321,200,000	157,200,000	100,000	9,498,500,000	1,944,000,000	2,081,200,000		1,002,600,000	1,012,800,000	1,039,500,000	1,492,200,000	13,211,300,000		3,380,300,000	2,933,200,000		2,191,800,000	2,326,300,000	1,412,600,000	2,269,300,000	(40,000,000.0)	(4,700,000)	(2,500,000)	(500,000)	(200,000)	(3,600,000)	40,500,000	300,000
Ending Balance, Shares at Jun. 30, 2024																																																																533,100,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends Per Share, Declared	$ 0.88
Issuance of Common Stock, Value	$ 37,200,000																																																															$ 3,300,000						33,900,000
Issuance of Common Stock, Shares																																																																600,000
Common Stock Dividends	(471,400,000)																																																																													(470,200,000)	[10]
Common Stock Dividends																												(75,000,000.0)				(150,000,000.0)																(37,500,000)								(35,000,000.0)				(100,000,000.0)																				(75,000,000.0)	(150,000,000.0)		(37,500,000)		(35,000,000.0)	(100,000,000.0)
Common Stock Dividends																																																												(1,000,000.0)																																	(1,200,000)	(1,000,000.0)
Other Changes in Equity	2,500,000																																																																					2,500,000
Capital Contributions from Parent																																																				800,000																							800,000
Return of Capital to Parent																												(4,500,000)				(700,000)				(4,500,000)												(1,800,000)												(1,100,000)											(4,500,000)	(700,000)	(4,500,000)	(1,800,000)			(1,100,000)
Dividends Paid on Common Stock																																				(26,000,000.0)																																														(26,000,000.0)
Net Income (Loss)	959,600,000																																																											139,100,000																		959,600,000								139,100,000
Net Income (Loss) Attributable to Noncontrolling Interests	2,100,000																																																											1,000,000.0																																	2,100,000	1,000,000.0
Net Income (Loss)	961,700,000						0			93,300,000				(165,100,000)				215,800,000		245,200,000				572,500,000				109,800,000				132,500,000				191,300,000				0		190,800,000			500,000	[3]		179,100,000				112,700,000				113,700,000				140,100,000																				109,800,000	132,500,000	191,300,000	179,100,000	112,700,000	113,700,000
Other Comprehensive Income (Loss)	(46,900,000)																											(400,000)				(100,000)																100,000								(8,600,000)				(200,000)																											(46,900,000)	(400,000)	(100,000)	100,000	(8,600,000)	(200,000)
Ending Balance at Sep. 30, 2024																																				6,814,600,000																																					$ 3,073,500,000									$ 3,741,100,000
Ending Balance at Sep. 30, 2024	$ 26,658,800,000																											5,609,900,000				4,993,600,000																3,390,400,000				3,773,800,000				$ 2,679,200,000				3,796,100,000				$ 3,468,700,000	$ 260,400,000	$ 56,600,000	$ 321,200,000	$ 157,200,000	$ 100,000	$ 9,534,900,000	$ 1,939,500,000	$ 2,080,500,000		$ 1,000,800,000	$ 1,013,600,000	$ 1,039,500,000	$ 1,491,100,000	$ 13,700,700,000		$ 3,415,100,000	$ 2,915,700,000		$ 2,333,400,000	$ 2,439,000,000	$ 1,491,300,000	$ 2,308,400,000	$ (86,900,000)	$ (5,100,000)	$ (2,600,000)	$ (400,000)	$ (8,800,000)	$ (3,800,000)	$ 41,400,000	$ 300,000
Ending Balance, Shares at Sep. 30, 2024	533,652,728																																																							10,482,000								533,700,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends Per Share, Declared	$ 0.88
Revenue from Contracts with Customers	$ 5,420,100,000	$ 3,248,800,000	$ 1,568,500,000	$ 483,700,000	119,100,000		0				$ 483,700,000					6,000,000.0	[2]		$ 113,100,000		$ 1,568,500,000				$ 3,248,800,000				$ 960,600,000	3,100,000			$ 569,200,000	700,000			103,300,000	200,000		0	$ 0		$ 101,100,000	$ 200,000	0		$ 0		$ 714,900,000	2,100,000			$ 995,800,000	2,800,000			$ 612,900,000	1,400,000			$ 625,100,000	700,000
Revenues	$ 5,420,100,000				$ (62,800,000)	[14],[15]	$ (508,000,000.0)	$ (700,000)	[14],[15]	$ 499,100,000		$ (65,100,000)	[14],[15]	$ 38,100,000		$ 700,000	[14],[15]	$ 512,500,000		$ 1,575,400,000		$ 3,300,000	[14],[15]	$ 3,303,000,000		$ (1,000,000.0)	[14],[15]	$ 1,028,900,000		$ 100,000	[16]	$ 571,200,000		$ 0	[16]	497,200,000		0	[16]	$ 0		$ 497,200,000			$ 0			$ 733,500,000		$ (1,200,000)	[16]	$ 1,004,200,000		$ 3,300,000	[16]	$ 615,400,000		$ 0	[16]	$ 638,800,000		$ 0	[16]
Revenues from Related Parties, Net of Provisions for Refund																																				$ 395,900,000
Revenue from Contract with Customers, Net of Provisions for Refund, Including Assessed Tax																																					$ 101,100,000	$ 200,000

[1] Cash dividends declared per AEP common share were $0.83.

[2] 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 and interest expense, income tax expense and other nonallocated costs.

[3] Includes the elimination of AEPTCo Parent’s equity earnings in the State Transcos.

[4] Generation & Marketing includes economic hedge activity.

[5] Amounts include affiliated and nonaffiliated revenues

[6] Amounts include affiliated and nonaffiliated revenues.

[7] Generation & Marketing includes economic hedge activity.

[8] Amounts include affiliated and nonaffiliated revenues

[9] Amounts include affiliated and nonaffiliated revenues.

[10] Cash dividends declared per AEP common share were $0.88.

[11] Amounts include affiliated and nonaffiliated revenues.

[12] Generation & Marketing includes economic hedge activity.

[13] Amounts include affiliated and nonaffiliated revenues.

[14] Amounts include affiliated and nonaffiliated revenues.

[15] Generation & Marketing includes economic hedge activity.

[16] Amounts include affiliated and nonaffiliated revenues.