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 Segments [Member]	[2]	Other Segments [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] State Transcos [Member]	AEP Transmission Co [Member] State Transcos [Member] Transmission [Member]	AEP Transmission Co [Member] AEPTCo Parent [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 [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] 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]	Competitive Contracted Renewable Portfolio	Competitive Contracted Renewable Portfolio Noncontrolling Interests [Member]
Beginning Balance at Dec. 31, 2021																																				$ 5,376,100,000																																		$ 2,949,600,000									$ 2,426,500,000
Beginning Balance at Dec. 31, 2021	$ 22,680,200,000																											$ 4,647,900,000				$ 3,594,200,000													$ 2,784,700,000				$ 2,846,300,000				$ 2,291,600,000				$ 3,149,800,000				$ 3,408,700,000	$ 260,400,000	$ 56,600,000	$ 321,200,000	$ 157,200,000	$ 100,000	$ 7,172,600,000	$ 1,828,700,000	$ 1,553,900,000		$ 980,900,000	$ 838,800,000	$ 1,039,000,000	$ 1,092,200,000	$ 11,667,100,000		$ 2,534,400,000	$ 2,046,800,000		$ 1,748,500,000	$ 1,686,300,000	$ 1,095,400,000	$ 2,050,900,000	$ 184,800,000	$ 24,400,000	$ (6,500,000)	$ (1,300,000)	$ 0	$ 6,700,000	$ 247,000,000.0	$ (100,000)
Beginning Balance, Shares at Dec. 31, 2021																																																													524,400,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock, Value	809,500,000																																																												$ 2,400,000						807,100,000
Issuance of Common Stock, Shares																																																													400,000
Common Stock Dividends	(398,800,000)																																																																										(395,200,000)	[1]
Common Stock Dividends																												(18,800,000)																	(25,000,000.0)				(15,000,000.0)																												(18,800,000)			(25,000,000.0)	(15,000,000.0)
Common Stock Dividends																																																									(800,000)																																	(3,600,000)	(800,000)
Other Changes in Equity	(16,700,000)																																																																		(15,200,000)								(1,500,000)
Capital Contribution from Member																																																									350,000,000.0																	350,000,000.0
Dividends Paid on Common Stock																																				(40,000,000.0)																																											(40,000,000.0)
Net Income (Loss)																																																																											714,700,000								44,100,000
Net Income (Loss) Attributable to Noncontrolling Interests																																																																																										3,400,000	1,000,000.0
Net Income (Loss)	718,100,000																											120,200,000				69,600,000				155,400,000									89,500,000				83,200,000				5,800,000				45,100,000																				120,200,000	69,600,000	155,400,000	89,500,000	83,200,000	5,800,000
Other Comprehensive Income (Loss)	245,800,000																											(1,300,000)				300,000													300,000												(300,000)																											245,800,000	(1,300,000)	300,000	300,000		(300,000)
Ending Balance at Mar. 31, 2022																																				5,491,500,000																																		2,949,600,000									2,541,900,000
Ending Balance at Mar. 31, 2022	$ 24,038,100,000																											4,748,000,000				3,664,100,000													2,849,500,000				2,914,500,000				2,297,400,000				3,543,800,000				$ 3,411,100,000	260,400,000	56,600,000	321,200,000	157,200,000	100,000	7,964,500,000	1,828,700,000	1,553,900,000		980,900,000	838,800,000	1,039,000,000	1,442,200,000	11,985,100,000		2,635,800,000	2,116,400,000		1,813,000,000	1,754,500,000	1,101,200,000	2,095,000,000	430,600,000	23,100,000	(6,200,000)	(1,000,000.0)	0	6,400,000	246,800,000	100,000
Ending Balance, Shares at Mar. 31, 2022																																																													524,800,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends Per Share, Declared	$ 0.78
Beginning Balance at Dec. 31, 2021																																				5,376,100,000																																		2,949,600,000									2,426,500,000
Beginning Balance at Dec. 31, 2021	$ 22,680,200,000																											4,647,900,000				3,594,200,000													2,784,700,000				2,846,300,000				2,291,600,000				3,149,800,000				$ 3,408,700,000	260,400,000	56,600,000	321,200,000	157,200,000	100,000	7,172,600,000	1,828,700,000	1,553,900,000		980,900,000	838,800,000	1,039,000,000	1,092,200,000	11,667,100,000		2,534,400,000	2,046,800,000		1,748,500,000	1,686,300,000	1,095,400,000	2,050,900,000	184,800,000	24,400,000	(6,500,000)	(1,300,000)	0	6,700,000	247,000,000.0	(100,000)
Beginning Balance, Shares at Dec. 31, 2021																																																													524,400,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends Paid on Common Stock																												(37,500,000)								(130,000,000.0)									(70,000,000.0)				(45,000,000.0)				(20,000,000.0)				(57,500,000)
Net Income (Loss)	1,922,900,000																																																								260,200,000
Net Income (Loss) Attributable to Noncontrolling Interests	(700,000)																																																								3,100,000
Net Income (Loss)	1,922,200,000						$ 0			$ 278,100,000				$ (406,200,000)				$ 487,800,000		$ 483,100,000				$ 1,079,400,000				303,100,000				253,200,000				426,600,000				$ 0	$ 426,400,000		$ 200,000	[3]	250,800,000				229,900,000				155,700,000				263,300,000
Other Comprehensive Income (Loss)	290,100,000																											(3,800,000)				800,000													900,000												(1,200,000)
Ending Balance at Sep. 30, 2022																																				5,736,900,000																																		3,013,800,000									2,723,100,000
Ending Balance at Sep. 30, 2022	24,512,300,000																											4,914,000,000				3,850,000,000													2,968,300,000				3,032,200,000				2,430,600,000				3,705,100,000				$ 3,412,500,000	260,400,000	56,600,000	321,200,000	157,200,000	100,000	8,001,000,000	1,833,000,000	1,555,700,000		982,800,000	839,800,000	1,042,300,000	1,445,500,000	12,389,800,000		2,800,000,000	2,300,000,000		1,929,300,000	1,871,200,000	1,231,100,000	2,253,600,000	474,900,000	20,600,000	(5,700,000)	(400,000)	0	5,500,000	234,100,000	400,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital Contributions from Parent																												4,300,000				1,800,000				64,200,000									1,900,000				1,000,000.0				3,300,000				353,300,000
Ending Balance, Shares at Sep. 30, 2022																																																													525,000,000.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Revenue from Contracts with Customers	14,758,400,000	$ 8,416,400,000	$ 4,064,500,000	$ 1,997,000,000	$ 280,500,000		0				$ 1,997,000,000					$ 36,100,000	[2]		$ 244,400,000		$ 4,064,500,000				$ 8,416,400,000				$ 2,370,400,000	$ 11,800,000			$ 1,399,300,000	$ 2,500,000			$ 261,700,000			0		$ 249,500,000	0			$ 1,912,100,000	$ 10,000,000.0			$ 2,656,600,000	$ 6,000,000.0			$ 1,432,900,000	$ 3,700,000			$ 1,703,700,000	$ 1,500,000
Revenues	14,758,400,000				429,400,000	[4],[5]	(1,190,500,000)	$ (6,900,000)	[4],[5]	2,014,300,000		$ 410,500,000	[4],[5]	72,700,000		6,900,000	[4],[5]	1,221,100,000		4,078,600,000		$ 18,600,000	[4],[5]	8,562,200,000		$ 300,000	[4],[5]	2,569,800,000		400,000	[6]	1,404,400,000		0	[6]	1,183,300,000		$ 0	[6]	0	1,183,300,000		0		1,971,600,000		(100,000)	[6]	2,674,200,000		18,600,000	[6]	1,438,700,000		0	[6]	1,748,900,000		0	[6]
Revenues from Related Parties, Net of Provisions for Refund																																				933,800,000
Beginning Balance at Mar. 31, 2022																																				5,491,500,000																																		2,949,600,000									2,541,900,000
Beginning Balance at Mar. 31, 2022	24,038,100,000																											4,748,000,000				3,664,100,000													2,849,500,000				2,914,500,000				2,297,400,000				3,543,800,000				$ 3,411,100,000	260,400,000	56,600,000	321,200,000	157,200,000	100,000	7,964,500,000	1,828,700,000	1,553,900,000		980,900,000	838,800,000	1,039,000,000	1,442,200,000	11,985,100,000		2,635,800,000	2,116,400,000		1,813,000,000	1,754,500,000	1,101,200,000	2,095,000,000	430,600,000	23,100,000	(6,200,000)	(1,000,000.0)	0	6,400,000	246,800,000	100,000
Beginning Balance, Shares at Mar. 31, 2022																																																													524,800,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock, Value	3,200,000																																																												$ 900,000						2,300,000
Issuance of Common Stock, Shares																																																													100,000
Common Stock Dividends	(404,700,000)																																																																										(402,600,000)	[1]
Common Stock Dividends																												(18,700,000)																	(25,000,000.0)				(15,000,000.0)								(12,500,000)																				(18,700,000)			(25,000,000.0)	(15,000,000.0)		(12,500,000)
Common Stock Dividends																																																									(700,000)																																	(2,100,000)	(700,000)
Other Changes in Equity	18,800,000																																																																		17,200,000								1,600,000
Capital Contribution from Member																																1,300,000				2,800,000									1,300,000				700,000				2,200,000				2,200,000												1,300,000	2,800,000	1,300,000	700,000	2,200,000	2,200,000
Dividends Paid on Common Stock																																				(50,000,000.0)																																											(50,000,000.0)
Net Income (Loss)																																																																											524,500,000								76,700,000
Net Income (Loss) Attributable to Noncontrolling Interests																																																																																										(3,700,000)	2,100,000
Net Income (Loss)	520,800,000																											90,200,000				90,000,000.0				118,500,000									67,200,000				74,800,000				43,000,000.0				78,800,000																				90,200,000	90,000,000.0	118,500,000	67,200,000	74,800,000	43,000,000.0
Other Comprehensive Income (Loss)	120,800,000																											(1,200,000)				200,000													300,000												(500,000)																											120,800,000	(1,200,000)	200,000	300,000		(500,000)
Ending Balance at Jun. 30, 2022																																				5,562,800,000																																		2,952,400,000									2,610,400,000
Ending Balance at Jun. 30, 2022	$ 24,297,000,000																											4,821,100,000				3,755,600,000													2,893,300,000				2,975,000,000				2,342,600,000				3,611,100,000				$ 3,412,000,000	260,400,000	56,600,000	321,200,000	157,200,000	100,000	7,984,000,000	1,831,500,000	1,555,200,000		982,200,000	839,500,000	1,041,200,000	1,444,400,000	12,108,600,000		2,707,300,000	2,206,400,000		1,855,200,000	1,814,300,000	1,144,200,000	2,159,200,000	551,400,000	21,900,000	(6,000,000.0)	(700,000)	0	5,900,000	241,000,000.0	1,500,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital Contributions from Parent																												2,800,000																																								2,800,000
Ending Balance, Shares at Jun. 30, 2022																																																													524,900,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends Per Share, Declared	$ 0.78
Issuance of Common Stock, Value	$ 14,500,000																																																												$ 500,000						14,000,000.0
Issuance of Common Stock, Shares																																																													100,000
Common Stock Dividends	(409,000,000.0)																																																				(20,000,000.0)																						(402,500,000)	[1]						(20,000,000.0)
Common Stock Dividends																																													(20,000,000.0)				(15,000,000.0)								(45,000,000.0)																							(20,000,000.0)	(15,000,000.0)		(45,000,000.0)
Common Stock Dividends																																																									(1,100,000)																																	(6,500,000)	(1,100,000)
Other Changes in Equity	3,000,000.0																																																																		3,000,000.0
Capital Contribution from Member																																500,000				61,400,000									600,000				300,000				1,100,000				1,100,000												500,000	61,400,000	600,000	300,000	1,100,000	1,100,000
Dividends Paid on Common Stock																																				(40,000,000.0)																																											(40,000,000.0)
Net Income (Loss)	683,700,000																																																								139,400,000																		683,700,000								139,400,000
Net Income (Loss) Attributable to Noncontrolling Interests	(400,000)																																																								0																																	(400,000)	0
Net Income (Loss)	683,300,000						0			96,200,000				(226,700,000)				171,400,000		165,500,000				476,900,000				92,700,000				93,600,000				152,700,000				0	152,600,000		100,000	[3]	94,100,000				71,900,000				106,900,000				139,400,000																				92,700,000	93,600,000	152,700,000	94,100,000	71,900,000	106,900,000
Other Comprehensive Income (Loss)	(76,500,000)																											(1,300,000)				300,000													300,000												(400,000)																											(76,500,000)	(1,300,000)	300,000	300,000		(400,000)
Ending Balance at Sep. 30, 2022																																				5,736,900,000																																		3,013,800,000									2,723,100,000
Ending Balance at Sep. 30, 2022	$ 24,512,300,000																											4,914,000,000				3,850,000,000													2,968,300,000				3,032,200,000				2,430,600,000				3,705,100,000				$ 3,412,500,000	260,400,000	56,600,000	321,200,000	157,200,000	100,000	8,001,000,000	1,833,000,000	1,555,700,000		982,800,000	839,800,000	1,042,300,000	1,445,500,000	12,389,800,000		2,800,000,000	2,300,000,000		1,929,300,000	1,871,200,000	1,231,100,000	2,253,600,000	474,900,000	20,600,000	(5,700,000)	(400,000)	0	5,500,000	234,100,000	400,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital Contributions from Parent																												1,500,000																																								1,500,000
Ending Balance, Shares at Sep. 30, 2022																																																													525,000,000.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends Per Share, Declared	$ 0.78
Revenue from Contracts with Customers	$ 5,526,100,000	3,174,600,000	1,525,500,000	733,100,000	92,900,000		0				733,100,000					11,000,000.0	[2]		81,900,000		1,525,500,000				3,174,600,000				818,400,000	2,900,000			507,700,000	300,000			89,100,000			0		87,200,000	0			695,700,000	4,400,000			1,015,200,000	2,100,000			606,500,000	1,000,000.0			698,800,000	500,000
Revenues	5,526,100,000				128,300,000	[7],[8]	(425,000,000.0)	(2,000,000.0)	[7],[8]	735,400,000		122,800,000	[7],[8]	28,300,000		1,800,000	[7],[8]	430,900,000		1,530,200,000		5,500,000	[7],[8]	3,226,300,000		200,000	[7],[8]	888,900,000		300,000	[9]	508,900,000		0	[9]	418,500,000		0	[9]	0	418,500,000		0		715,400,000		0	[9]	1,021,300,000		5,500,000	[9]	608,200,000		0	[9]	717,500,000		0	[9]
Revenues from Related Parties, Net of Provisions for Refund																																				331,300,000
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	525,099,321																																																				10,482,000								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)	[10]
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 Member																																100,000,000.0				25,000,000.0													50,000,000.0								50,000,000.0												100,000,000.0	25,000,000.0		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	525,099,321																																																				10,482,000								525,100,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends Paid on Common Stock																												0								(115,000,000.0)									(137,500,000)				0				$ (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
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
Ending Balance, Shares at Sep. 30, 2023	526,819,992																																																				10,482,000								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		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			1,666,000,000	1,800,000
Revenues	14,405,100,000				(250,200,000)	[11],[12]	(1,416,300,000)	(3,600,000)	[11],[12]	1,225,100,000		(272,800,000)	[11],[12]	119,300,000		4,000,000.0	[11],[12]	1,390,800,000		4,348,500,000		20,000,000.0	[11],[12]	8,737,700,000		2,200,000	[11],[12]	2,776,000,000		100,000	[13]	1,445,300,000		0	[13]	1,349,200,000		0	[13]	0	1,349,200,000		0		1,938,500,000		2,100,000	[13]	2,903,200,000		20,100,000	[13]	$ 1,535,900,000		0	[13]	1,708,500,000		0	[13]
Revenues from Related Parties, Net of Provisions for Refund																																				1,080,000,000
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)	[10]
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 Member																																175,300,000													100,000				125,000,000.0																				175,300,000		100,000	125,000,000.0
Return of Capital to Parent Equity Statement																																(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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital Contributions from Parent																												4,300,000																																								4,300,000
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)																																																																										(429,700,000)	[10]
Common Stock Dividends																																													(75,000,000.0)								(17,500,000)				(75,000,000.0)																							(75,000,000.0)		(17,500,000)	(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 Member																																250,500,000				2,900,000									1,600,000								600,000																250,500,000	2,900,000	1,600,000		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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital Contributions from Parent																												2,200,000																																								$ 2,200,000
Ending Balance, Shares at Sep. 30, 2023	526,819,992																																																				10,482,000								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		$ 92,800,000	0			$ 656,100,000	4,200,000			$ 978,700,000	3,000,000.0			$ 642,600,000	1,400,000			$ 639,800,000	500,000
Revenues	$ 5,341,700,000				$ 8,500,000	[14]	$ (508,400,000)	$ (700,000)	[14]	$ 566,700,000		$ 3,400,000	[14],[15]	$ 57,200,000		$ 800,000	[14]	$ 476,700,000		$ 1,544,100,000		$ 2,800,000	[14]	$ 3,205,400,000		$ 2,200,000	[14]	$ 961,800,000		$ 100,000	[16]	$ 554,600,000		$ 0	[16]	462,700,000		$ 0	[16]	$ 0	$ 462,700,000		$ 0		$ 676,300,000		$ 2,100,000	[16]	$ 989,500,000		$ 3,000,000.0	[16]	$ 644,200,000		$ 0	[16]	$ 654,800,000		$ 0	[16]
Revenues from Related Parties, Net of Provisions for Refund																																				$ 369,900,000

[1] Cash dividends declared per AEP common share were $0.78.

[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, interest expense and other nonallocated costs.

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

[4] Amounts include affiliated and nonaffiliated revenues

[5] Generation & Marketing includes economic hedge activity.

[6] Amounts include affiliated and nonaffiliated revenues.

[7] Amounts include affiliated and nonaffiliated revenues

[8] Generation & Marketing includes economic hedge activity.

[9] Amounts include affiliated and nonaffiliated revenues.

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

[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.