BENEFIT PLANS - Schedule of Obligation and Funded Status (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Qualified Plans
Change in Fair Value of Plan Assets
Company Contributions	$ 0	$ 0
Nonqualified Plans
Change in Fair Value of Plan Assets
Company Contributions	14,000,000	8,000,000
Pension Plans
Change in Benefit Obligation
Benefit Obligation as of January 1,	4,161,600,000	4,072,700,000
Service Cost	100,600,000	94,300,000	$ 123,100,000
Interest Cost	207,400,000	219,200,000	148,200,000
Actuarial (Gain) Loss	(44,600,000)	144,000,000.0
Settlements	(329,400,000)
Benefit Payments	(223,800,000)	(368,600,000)
Benefit Obligation as of December 31,	3,871,800,000	4,161,600,000	4,072,700,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1,	4,118,200,000	4,124,700,000
Actual Gain on Plan Assets	87,200,000	353,800,000
Company Contributions	14,000,000.0	8,300,000
Settlements	(329,400,000)
Benefit Payments	(223,800,000)	(368,600,000)
Fair Value of Plan Assets as of December 31,	3,666,200,000	4,118,200,000	4,124,700,000
Funded (Underfunded) Status as of December 31,	(205,600,000)	(43,400,000)
Pension Plans | AEP TEXAS INC.
Change in Benefit Obligation
Benefit Obligation as of January 1,	343,100,000	334,100,000
Service Cost	8,900,000	8,200,000	11,100,000
Interest Cost	17,300,000	18,300,000	12,100,000
Actuarial (Gain) Loss	5,500,000	20,100,000
Settlements	(34,800,000)
Benefit Payments	(17,300,000)	(37,600,000)
Benefit Obligation as of December 31,	322,700,000	343,100,000	334,100,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1,	332,700,000	335,100,000
Actual Gain on Plan Assets	7,100,000	34,800,000
Company Contributions	400,000	400,000
Settlements	(34,800,000)
Benefit Payments	(17,300,000)	(37,600,000)
Fair Value of Plan Assets as of December 31,	288,100,000	332,700,000	335,100,000
Funded (Underfunded) Status as of December 31,	(34,600,000)	(10,400,000)
Pension Plans | APPALACHIAN POWER COMPANY
Change in Benefit Obligation
Benefit Obligation as of January 1,	504,100,000	485,700,000
Service Cost	9,500,000	9,100,000	11,400,000
Interest Cost	24,700,000	26,400,000	17,500,000
Actuarial (Gain) Loss	(12,900,000)	23,200,000
Settlements	(42,000,000.0)
Benefit Payments	(30,400,000)	(40,300,000)
Benefit Obligation as of December 31,	453,000,000.0	504,100,000	485,700,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1,	549,800,000	531,700,000
Actual Gain on Plan Assets	10,400,000	58,400,000
Company Contributions	0	0
Settlements	(42,000,000.0)
Benefit Payments	(30,400,000)	(40,300,000)
Fair Value of Plan Assets as of December 31,	487,800,000	549,800,000	531,700,000
Funded (Underfunded) Status as of December 31,	34,800,000	45,700,000
Pension Plans | INDIANA MICHIGAN POWER COMPANY
Change in Benefit Obligation
Benefit Obligation as of January 1,	477,000,000.0	466,800,000
Service Cost	13,000,000.0	11,900,000	16,200,000
Interest Cost	23,900,000	24,900,000	17,000,000.0
Actuarial (Gain) Loss	(8,400,000)	8,500,000
Settlements	(33,100,000)
Benefit Payments	(22,600,000)	(35,100,000)
Benefit Obligation as of December 31,	449,800,000	477,000,000.0	466,800,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1,	550,600,000	533,700,000
Actual Gain on Plan Assets	11,600,000	51,500,000
Company Contributions	0	500,000
Settlements	(33,100,000)
Benefit Payments	(22,600,000)	(35,100,000)
Fair Value of Plan Assets as of December 31,	506,500,000	550,600,000	533,700,000
Funded (Underfunded) Status as of December 31,	56,700,000	73,600,000
Pension Plans | OHIO POWER COMPANY
Change in Benefit Obligation
Benefit Obligation as of January 1,	378,400,000	363,600,000
Service Cost	9,200,000	8,400,000	11,200,000
Interest Cost	18,800,000	19,800,000	13,300,000
Actuarial (Gain) Loss	(8,300,000)	17,500,000
Settlements	(23,200,000)
Benefit Payments	(24,200,000)	(30,900,000)
Benefit Obligation as of December 31,	350,700,000	378,400,000	363,600,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1,	419,500,000	406,400,000
Actual Gain on Plan Assets	8,600,000	44,000,000.0
Company Contributions	0	0
Settlements	(23,200,000)
Benefit Payments	(24,200,000)	(30,900,000)
Fair Value of Plan Assets as of December 31,	380,700,000	419,500,000	406,400,000
Funded (Underfunded) Status as of December 31,	30,000,000.0	41,100,000
Pension Plans | PUBLIC SERVICE COMPANY OF OKLAHOMA
Change in Benefit Obligation
Benefit Obligation as of January 1,	202,200,000	192,300,000
Service Cost	5,900,000	5,500,000	7,400,000
Interest Cost	10,100,000	10,700,000	7,000,000.0
Actuarial (Gain) Loss	100,000	13,600,000
Settlements	(18,500,000)
Benefit Payments	(9,600,000)	(19,900,000)
Benefit Obligation as of December 31,	190,200,000	202,200,000	192,300,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1,	222,700,000	218,500,000
Actual Gain on Plan Assets	5,000,000.0	24,000,000.0
Company Contributions	100,000	100,000
Settlements	(18,500,000)
Benefit Payments	(9,600,000)	(19,900,000)
Fair Value of Plan Assets as of December 31,	199,700,000	222,700,000	218,500,000
Funded (Underfunded) Status as of December 31,	9,500,000	20,500,000
Pension Plans | SOUTHWESTERN ELECTRIC POWER COMPANY
Change in Benefit Obligation
Benefit Obligation as of January 1,	261,200,000	250,700,000
Service Cost	7,800,000	7,700,000	10,600,000
Interest Cost	12,500,000	13,900,000	9,100,000
Actuarial (Gain) Loss	(11,200,000)	16,800,000
Settlements	(33,100,000)
Benefit Payments	(9,400,000)	(27,900,000)
Benefit Obligation as of December 31,	227,800,000	261,200,000	250,700,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1,	227,500,000	231,300,000
Actual Gain on Plan Assets	3,600,000	23,900,000
Company Contributions	200,000	200,000
Settlements	(33,100,000)
Benefit Payments	(9,400,000)	(27,900,000)
Fair Value of Plan Assets as of December 31,	188,800,000	227,500,000	231,300,000
Funded (Underfunded) Status as of December 31,	(39,000,000.0)	(33,700,000)
OPEB
Change in Benefit Obligation
Benefit Obligation as of January 1,	849,500,000	872,600,000
Service Cost	4,500,000	4,600,000	7,400,000
Interest Cost	42,000,000.0	46,200,000	29,200,000
Actuarial (Gain) Loss	(192,300,000)	19,800,000
Special/Contractual Termination Benefits	3,500,000
Benefit Payments	(105,800,000)	(137,800,000)
Participant Contributions	44,900,000	43,600,000
Medicare Subsidy	300,000	500,000
Benefit Obligation as of December 31,	646,600,000	849,500,000	872,600,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1,	1,673,300,000	1,549,300,000
Actual Gain on Plan Assets	159,200,000	213,200,000
Company Contributions	4,300,000	5,000,000.0
Participant Contributions	44,900,000	43,600,000
Benefit Payments	(105,800,000)	(137,800,000)
Fair Value of Plan Assets as of December 31,	1,775,900,000	1,673,300,000	1,549,300,000
Funded (Underfunded) Status as of December 31,	1,129,300,000	823,800,000
OPEB | AEP TEXAS INC.
Change in Benefit Obligation
Benefit Obligation as of January 1,	66,400,000	68,600,000
Service Cost	300,000	300,000	500,000
Interest Cost	3,300,000	3,600,000	2,200,000
Actuarial (Gain) Loss	(15,400,000)	1,200,000
Special/Contractual Termination Benefits	400,000
Benefit Payments	(8,300,000)	(10,700,000)
Participant Contributions	3,500,000	3,400,000
Medicare Subsidy	0	0
Benefit Obligation as of December 31,	50,200,000	66,400,000	68,600,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1,	137,500,000	128,300,000
Actual Gain on Plan Assets	14,000,000.0	16,500,000
Company Contributions	0	0
Participant Contributions	3,500,000	3,400,000
Benefit Payments	(8,300,000)	(10,700,000)
Fair Value of Plan Assets as of December 31,	146,700,000	137,500,000	128,300,000
Funded (Underfunded) Status as of December 31,	96,500,000	71,100,000
OPEB | APPALACHIAN POWER COMPANY
Change in Benefit Obligation
Benefit Obligation as of January 1,	134,600,000	140,700,000
Service Cost	500,000	500,000	800,000
Interest Cost	6,600,000	7,400,000	4,700,000
Actuarial (Gain) Loss	(30,400,000)	900,000
Special/Contractual Termination Benefits	600,000
Benefit Payments	(16,700,000)	(21,600,000)
Participant Contributions	6,800,000	6,600,000
Medicare Subsidy	100,000	100,000
Benefit Obligation as of December 31,	102,100,000	134,600,000	140,700,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1,	243,000,000.0	228,600,000
Actual Gain on Plan Assets	22,500,000	28,100,000
Company Contributions	800,000	1,300,000
Participant Contributions	6,800,000	6,600,000
Benefit Payments	(16,700,000)	(21,600,000)
Fair Value of Plan Assets as of December 31,	256,400,000	243,000,000.0	228,600,000
Funded (Underfunded) Status as of December 31,	154,300,000	108,400,000
OPEB | INDIANA MICHIGAN POWER COMPANY
Change in Benefit Obligation
Benefit Obligation as of January 1,	98,800,000	101,900,000
Service Cost	600,000	600,000	900,000
Interest Cost	4,800,000	5,400,000	3,400,000
Actuarial (Gain) Loss	(24,700,000)	3,200,000
Special/Contractual Termination Benefits	400,000
Benefit Payments	(13,400,000)	(18,300,000)
Participant Contributions	6,000,000.0	6,000,000.0
Medicare Subsidy	0	0
Benefit Obligation as of December 31,	72,500,000	98,800,000	101,900,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1,	204,600,000	190,500,000
Actual Gain on Plan Assets	14,700,000	26,400,000
Company Contributions	0	0
Participant Contributions	6,000,000.0	6,000,000.0
Benefit Payments	(13,400,000)	(18,300,000)
Fair Value of Plan Assets as of December 31,	211,900,000	204,600,000	190,500,000
Funded (Underfunded) Status as of December 31,	139,400,000	105,800,000
OPEB | OHIO POWER COMPANY
Change in Benefit Obligation
Benefit Obligation as of January 1,	85,900,000	88,900,000
Service Cost	400,000	400,000	600,000
Interest Cost	4,200,000	4,700,000	3,000,000.0
Actuarial (Gain) Loss	(20,700,000)	2,200,000
Special/Contractual Termination Benefits	300,000
Benefit Payments	(11,300,000)	(15,000,000.0)
Participant Contributions	4,600,000	4,700,000
Medicare Subsidy	0	0
Benefit Obligation as of December 31,	63,400,000	85,900,000	88,900,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1,	177,800,000	166,200,000
Actual Gain on Plan Assets	14,100,000	21,900,000
Company Contributions	0	0
Participant Contributions	4,600,000	4,700,000
Benefit Payments	(11,300,000)	(15,000,000.0)
Fair Value of Plan Assets as of December 31,	185,200,000	177,800,000	166,200,000
Funded (Underfunded) Status as of December 31,	121,800,000	91,900,000
OPEB | PUBLIC SERVICE COMPANY OF OKLAHOMA
Change in Benefit Obligation
Benefit Obligation as of January 1,	43,700,000	45,700,000
Service Cost	300,000	300,000	400,000
Interest Cost	2,100,000	2,400,000	1,500,000
Actuarial (Gain) Loss	(10,400,000)	400,000
Special/Contractual Termination Benefits	100,000
Benefit Payments	(5,800,000)	(7,600,000)
Participant Contributions	2,600,000	2,500,000
Medicare Subsidy	0	0
Benefit Obligation as of December 31,	32,600,000	43,700,000	45,700,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1,	90,200,000	85,400,000
Actual Gain on Plan Assets	8,300,000	9,900,000
Company Contributions	0	0
Participant Contributions	2,600,000	2,500,000
Benefit Payments	(5,800,000)	(7,600,000)
Fair Value of Plan Assets as of December 31,	95,300,000	90,200,000	85,400,000
Funded (Underfunded) Status as of December 31,	62,700,000	46,500,000
OPEB | SOUTHWESTERN ELECTRIC POWER COMPANY
Change in Benefit Obligation
Benefit Obligation as of January 1,	53,700,000	55,100,000
Service Cost	400,000	400,000	600,000
Interest Cost	2,700,000	2,900,000	1,800,000
Actuarial (Gain) Loss	(11,500,000)	1,200,000
Special/Contractual Termination Benefits	300,000
Benefit Payments	(7,400,000)	(8,800,000)
Participant Contributions	3,300,000	2,900,000
Medicare Subsidy	0	0
Benefit Obligation as of December 31,	41,500,000	53,700,000	55,100,000
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1,	111,100,000	103,000,000.0
Actual Gain on Plan Assets	14,200,000	14,000,000.0
Company Contributions	0	0
Participant Contributions	3,300,000	2,900,000
Benefit Payments	(7,400,000)	(8,800,000)
Fair Value of Plan Assets as of December 31,	121,200,000	111,100,000	$ 103,000,000.0
Funded (Underfunded) Status as of December 31,	$ 79,700,000	$ 57,400,000