Comprehensive Income (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		$ (85.1)	$ (147.7)	$ (120.4)
Change in Fair Value Recognized in AOCI		536.8	(66.4)	(69.7)
Commodity
Generation and Marketing Revenues		16,792.0	14,918.5	15,561.4
Interest Rate
Interest Expense		1,199.1	1,165.7	1,072.5
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		(337.9)	163.2	53.7
Income Tax (Expense) Benefit		115.5	40.5	(12.9)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		(266.9)	129.0	42.4
Net Current Period Other Comprehensive Income (Loss)		269.9	62.6	(27.3)
Ending Balance in AOCI		184.8	(85.1)	(147.7)
Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		123.7	130.7	136.3
Change in Fair Value Recognized in AOCI		0.0	0.0	0.0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		(10.3)	(8.9)	(7.1)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		(8.1)	(7.0)	(5.6)
Net Current Period Other Comprehensive Income (Loss)		(8.1)	(7.0)	(5.6)
Ending Balance in AOCI		115.6	123.7	130.7
Pension and OPEB [Member] | Changes in Funded Status [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(100.7)	(163.4)	(221.1)
Change in Fair Value Recognized in AOCI		27.5	62.7	57.7
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		0.0	0.0	0.0
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		0.0	0.0	0.0
Net Current Period Other Comprehensive Income (Loss)		27.5	62.7	57.7
Ending Balance in AOCI		(73.2)	(100.7)	(163.4)
Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)		269.9	62.6	(27.3)
Commodity [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(60.6)	(103.5)	(23.0)
Change in Fair Value Recognized in AOCI		488.2	(89.2)	(127.2)
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		(334.1)	167.2	59.3
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		(263.9)	132.1	46.7
Net Current Period Other Comprehensive Income (Loss)		224.3	42.9	(80.5)
Ending Balance in AOCI		163.7	(60.6)	(103.5)
Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(47.5)	(11.5)	(12.6)
Change in Fair Value Recognized in AOCI	[1]	21.1	(39.9)	(0.2)
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		6.5	4.9	1.5
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		5.1	3.9	1.3
Net Current Period Other Comprehensive Income (Loss)		26.2	(36.0)	1.1
Ending Balance in AOCI		(21.3)	(47.5)	(11.5)
Generation and Marketing Revenues [Member]
Commodity
Generation and Marketing Revenues		2,108.3	1,621.0	1,721.8
Apple Blossom and Black Oak [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Change in Fair Value Recognized in AOCI		(7.0)	6.0	4.0
AEP Texas Inc. [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(8.9)	(12.8)	(15.1)
Change in Fair Value Recognized in AOCI		1.3	2.7	1.1
Commodity
Generation and Marketing Revenues		1,587.7	1,528.0	1,551.6
Interest Rate
Interest Expense		176.5	171.8	137.2
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		1.4	1.5	1.5
Income Tax (Expense) Benefit		43.1	(11.2)	(53.6)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		1.1	1.2	1.2
Net Current Period Other Comprehensive Income (Loss)		2.4	3.9	2.3
Ending Balance in AOCI		(6.5)	(8.9)	(12.8)
AEP Texas Inc. [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		5.1	4.9	4.7
Change in Fair Value Recognized in AOCI		0.0	0.0	0.0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		0.2	0.2	0.2
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		0.2	0.2	0.2
Net Current Period Other Comprehensive Income (Loss)		0.2	0.2	0.2
Ending Balance in AOCI		5.3	5.1	4.9
AEP Texas Inc. [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(11.7)	(14.3)	(15.4)
Change in Fair Value Recognized in AOCI		1.2	2.6	1.1
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		0.0	0.0	0.0
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		0.0	0.0	0.0
Net Current Period Other Comprehensive Income (Loss)		1.2	2.6	1.1
Ending Balance in AOCI		(10.5)	(11.7)	(14.3)
AEP Texas Inc. [Member] | Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)		2.4	3.9	2.3
AEP Texas Inc. [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(2.3)	(3.4)	(4.4)
Change in Fair Value Recognized in AOCI		0.1	0.1	0.0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		1.2	1.3	1.3
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		0.9	1.0	1.0
Net Current Period Other Comprehensive Income (Loss)		1.0	1.1	1.0
Ending Balance in AOCI		(1.3)	(2.3)	(3.4)
Appalachian Power Co [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		7.2	5.0	(5.0)
Change in Fair Value Recognized in AOCI		22.3	7.0	13.4
Commodity
Generation and Marketing Revenues		3,092.9	2,809.2	2,911.1
Interest Rate
Interest Expense		214.0	217.6	205.0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		(6.4)	(6.1)	(4.3)
Income Tax (Expense) Benefit		22.1	4.3	(78.0)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		(5.1)	(4.8)	(3.4)
Net Current Period Other Comprehensive Income (Loss)		17.2	2.2	10.0
Ending Balance in AOCI		24.4	7.2	5.0
Appalachian Power Co [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		5.4	9.2	11.7
Change in Fair Value Recognized in AOCI		0.0	0.0	0.0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		(5.3)	(4.8)	(3.2)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		(4.2)	(3.8)	(2.5)
Net Current Period Other Comprehensive Income (Loss)		(4.2)	(3.8)	(2.5)
Ending Balance in AOCI		1.2	5.4	9.2
Appalachian Power Co [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		2.6	(5.1)	(18.5)
Change in Fair Value Recognized in AOCI		13.1	7.7	13.4
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		0.0	0.0	0.0
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		0.0	0.0	0.0
Net Current Period Other Comprehensive Income (Loss)		13.1	7.7	13.4
Ending Balance in AOCI		15.7	2.6	(5.1)
Appalachian Power Co [Member] | Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)		17.2	2.2	10.0
Appalachian Power Co [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(0.8)	0.9	1.8
Change in Fair Value Recognized in AOCI		9.2	(0.7)	0.0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		(1.1)	(1.3)	(1.1)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		(0.9)	(1.0)	(0.9)
Net Current Period Other Comprehensive Income (Loss)		8.3	(1.7)	(0.9)
Ending Balance in AOCI		7.5	(0.8)	0.9
Appalachian Power Co [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale		539.6	360.3	391.0
Indiana Michigan Power Co [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(7.0)	(11.6)	(13.8)
Change in Fair Value Recognized in AOCI		4.2	3.1	0.8
Commodity
Generation and Marketing Revenues		2,330.7	2,236.0	2,308.1
Interest Rate
Interest Expense		116.8	112.3	117.9
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		1.9	1.9	1.8
Income Tax (Expense) Benefit		(10.6)	(7.5)	(10.6)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		1.5	1.5	1.4
Net Current Period Other Comprehensive Income (Loss)		5.7	4.6	2.2
Ending Balance in AOCI		(1.3)	(7.0)	(11.6)
Indiana Michigan Power Co [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		4.8	4.9	5.1
Change in Fair Value Recognized in AOCI		0.0	0.0	0.0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		(0.1)	(0.1)	(0.2)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		(0.1)	(0.1)	(0.2)
Net Current Period Other Comprehensive Income (Loss)		(0.1)	(0.1)	(0.2)
Ending Balance in AOCI		4.7	4.8	4.9
Indiana Michigan Power Co [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(3.5)	(6.6)	(7.4)
Change in Fair Value Recognized in AOCI		4.2	3.1	0.8
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		0.0	0.0	0.0
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		0.0	0.0	0.0
Net Current Period Other Comprehensive Income (Loss)		4.2	3.1	0.8
Ending Balance in AOCI		0.7	(3.5)	(6.6)
Indiana Michigan Power Co [Member] | Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)		5.7	4.6	2.2
Indiana Michigan Power Co [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(8.3)	(9.9)	(11.5)
Change in Fair Value Recognized in AOCI		0.0	0.0	0.0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		2.0	2.0	2.0
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		1.6	1.6	1.6
Net Current Period Other Comprehensive Income (Loss)		1.6	1.6	1.6
Ending Balance in AOCI		(6.7)	(8.3)	(9.9)
Indiana Michigan Power Co [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale		176.8	182.2	232.3
Ohio Power Co [Member]
Commodity
Generation and Marketing Revenues		2,837.5	2,665.0	2,748.8
Interest Rate
Interest Expense		124.4	117.2	106.2
Pension and OPEB
Income Tax (Expense) Benefit		34.4	45.2	34.9
Net Current Period Other Comprehensive Income (Loss)				(1.0)
Ohio Power Co [Member] | Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)				(1.0)
Ohio Power Co [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		0.0	0.0	1.0
Change in Fair Value Recognized in AOCI		0.0	0.0	0.0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		0.0	0.0	(1.3)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		0.0	0.0	(1.0)
Net Current Period Other Comprehensive Income (Loss)		0.0	0.0	(1.0)
Ending Balance in AOCI		0.0	0.0	0.0
Ohio Power Co [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale		678.0	549.2	607.3
Public Service Co Of Oklahoma [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		0.1
Commodity
Generation and Marketing Revenues		1,474.3	1,263.9	1,512.8
Interest Rate
Interest Expense		62.9	60.3	66.5
Pension and OPEB
Income Tax (Expense) Benefit		4.1	5.2	7.5
Net Current Period Other Comprehensive Income (Loss)		(0.1)	(1.0)	(1.0)
Ending Balance in AOCI		0.0	0.1
Public Service Co Of Oklahoma [Member] | Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)		(0.1)	(1.0)	(1.0)
Public Service Co Of Oklahoma [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		0.1	1.1	2.1
Change in Fair Value Recognized in AOCI		0.0	0.0	0.0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		(0.1)	(1.3)	(1.3)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		(0.1)	(1.0)	(1.0)
Net Current Period Other Comprehensive Income (Loss)		(0.1)	(1.0)	(1.0)
Ending Balance in AOCI		0.0	0.1	1.1
Southwestern Electric Power Co [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		1.9	(1.3)	(5.4)
Change in Fair Value Recognized in AOCI		4.9	3.2	3.7
Commodity
Generation and Marketing Revenues		2,126.0	1,735.3	1,799.2
Interest Rate
Interest Expense		125.9	118.5	119.1
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		(0.1)	0.0	0.5
Income Tax (Expense) Benefit		(0.6)	9.4	(4.7)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		(0.1)	0.0	0.4
Net Current Period Other Comprehensive Income (Loss)		4.8	3.2	4.1
Ending Balance in AOCI		6.7	1.9	(1.3)
Southwestern Electric Power Co [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(2.8)	(1.3)	(0.2)
Change in Fair Value Recognized in AOCI		0.0	0.0	0.0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		(2.0)	(1.9)	(1.4)
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		(1.6)	(1.5)	(1.1)
Net Current Period Other Comprehensive Income (Loss)		(1.6)	(1.5)	(1.1)
Ending Balance in AOCI		(4.4)	(2.8)	(1.3)
Southwestern Electric Power Co [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		5.0	1.8	(1.9)
Change in Fair Value Recognized in AOCI		4.9	3.2	3.7
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		0.0	0.0	0.0
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		0.0	0.0	0.0
Net Current Period Other Comprehensive Income (Loss)		4.9	3.2	3.7
Ending Balance in AOCI		9.9	5.0	1.8
Southwestern Electric Power Co [Member] | Accumulated Other Comprehensive Income [Member]
Pension and OPEB
Net Current Period Other Comprehensive Income (Loss)		4.8	3.2	4.1
Southwestern Electric Power Co [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Beginning Balance in AOCI		(0.3)	(1.8)	(3.3)
Change in Fair Value Recognized in AOCI		0.0	0.0	0.0
Pension and OPEB
Reclassifications from AOCI, before Income Tax (Expense) Benefit		1.9	1.9	1.9
Reclassifications from AOCI, Net of Income Tax (Expense) Benefit		1.5	1.5	1.5
Net Current Period Other Comprehensive Income (Loss)		1.5	1.5	1.5
Ending Balance in AOCI		1.2	(0.3)	(1.8)
Reclassifications from Accumulated Other Comprehensive Income [Member]
Interest Rate
Interest Expense	[2]	6.5	4.9	1.5
Pension and OPEB
Amortization of Prior Service Cost (Credit)		(19.4)	(19.2)	(19.2)
Amortization of Actuarial (Gains) Losses		9.1	10.3	12.1
Income Tax (Expense) Benefit		(71.0)	34.2	11.3
Reclassifications from Accumulated Other Comprehensive Income [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Interest Rate
Interest Expense	[2]	0.0	0.0	0.0
Pension and OPEB
Amortization of Prior Service Cost (Credit)		(19.4)	(19.2)	(19.2)
Amortization of Actuarial (Gains) Losses		9.1	10.3	12.1
Income Tax (Expense) Benefit		(2.2)	(1.9)	(1.5)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Interest Rate
Interest Expense	[2]	0.0	0.0	0.0
Pension and OPEB
Amortization of Prior Service Cost (Credit)		0.0	0.0	0.0
Amortization of Actuarial (Gains) Losses		0.0	0.0	0.0
Income Tax (Expense) Benefit		0.0	0.0	0.0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Commodity [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Interest Rate
Interest Expense	[2]	0.0	0.0	0.0
Pension and OPEB
Amortization of Prior Service Cost (Credit)		0.0	0.0	0.0
Amortization of Actuarial (Gains) Losses		0.0	0.0	0.0
Income Tax (Expense) Benefit		(70.2)	35.1	12.6
Reclassifications from Accumulated Other Comprehensive Income [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Interest Rate
Interest Expense	[2]	6.5	4.9	1.5
Pension and OPEB
Amortization of Prior Service Cost (Credit)		0.0	0.0	0.0
Amortization of Actuarial (Gains) Losses		0.0	0.0	0.0
Income Tax (Expense) Benefit		1.4	1.0	0.2
Reclassifications from Accumulated Other Comprehensive Income [Member] | Generation and Marketing Revenues [Member]
Commodity
Generation and Marketing Revenues	[2]	0.7	(0.4)	(0.2)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Generation and Marketing Revenues [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Commodity
Generation and Marketing Revenues	[2]	0.0	0.0	0.0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Generation and Marketing Revenues [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Commodity
Generation and Marketing Revenues	[2]	0.0	0.0	0.0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Generation and Marketing Revenues [Member] | Commodity [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Commodity
Generation and Marketing Revenues	[2]	0.7	(0.4)	(0.2)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Generation and Marketing Revenues [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Commodity
Generation and Marketing Revenues	[2]	0.0	0.0	0.0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Purchased Electricity for Resale [Member]
Commodity
Purchased Electricity for Resale	[2]	(334.8)	167.6	59.5
Reclassifications from Accumulated Other Comprehensive Income [Member] | Purchased Electricity for Resale [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Commodity
Purchased Electricity for Resale	[2]	0.0	0.0	0.0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Purchased Electricity for Resale [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Commodity
Purchased Electricity for Resale	[2]	0.0	0.0	0.0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Purchased Electricity for Resale [Member] | Commodity [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Commodity
Purchased Electricity for Resale	[2]	(334.8)	167.6	59.5
Reclassifications from Accumulated Other Comprehensive Income [Member] | Purchased Electricity for Resale [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Commodity
Purchased Electricity for Resale	[2]	0.0	0.0	0.0
Reclassifications from Accumulated Other Comprehensive Income [Member] | AEP Texas Inc. [Member]
Interest Rate
Interest Expense	[2]	1.2	1.3	1.3
Pension and OPEB
Amortization of Prior Service Cost (Credit)		(0.1)	(0.1)	(0.1)
Amortization of Actuarial (Gains) Losses		0.3	0.3	0.3
Income Tax (Expense) Benefit		0.3	0.3	0.3
Reclassifications from Accumulated Other Comprehensive Income [Member] | AEP Texas Inc. [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Interest Rate
Interest Expense	[2]	0.0	0.0	0.0
Pension and OPEB
Amortization of Prior Service Cost (Credit)		(0.1)	(0.1)	(0.1)
Amortization of Actuarial (Gains) Losses		0.3	0.3	0.3
Income Tax (Expense) Benefit		0.0	0.0	0.0
Reclassifications from Accumulated Other Comprehensive Income [Member] | AEP Texas Inc. [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Interest Rate
Interest Expense	[2]	0.0	0.0	0.0
Pension and OPEB
Amortization of Prior Service Cost (Credit)		0.0	0.0	0.0
Amortization of Actuarial (Gains) Losses		0.0	0.0	0.0
Income Tax (Expense) Benefit		0.0	0.0	0.0
Reclassifications from Accumulated Other Comprehensive Income [Member] | AEP Texas Inc. [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Interest Rate
Interest Expense	[2]	1.2	1.3	1.3
Pension and OPEB
Amortization of Prior Service Cost (Credit)		0.0	0.0	0.0
Amortization of Actuarial (Gains) Losses		0.0	0.0	0.0
Income Tax (Expense) Benefit		0.3	0.3	0.3
Reclassifications from Accumulated Other Comprehensive Income [Member] | Appalachian Power Co [Member]
Interest Rate
Interest Expense	[2]	(1.1)	(1.3)	(1.1)
Pension and OPEB
Amortization of Prior Service Cost (Credit)		(5.3)	(5.3)	(5.3)
Amortization of Actuarial (Gains) Losses			0.5	2.1
Income Tax (Expense) Benefit		(1.3)	(1.3)	(0.9)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Appalachian Power Co [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Interest Rate
Interest Expense	[2]	0.0	0.0	0.0
Pension and OPEB
Amortization of Prior Service Cost (Credit)		(5.3)	(5.3)	(5.3)
Amortization of Actuarial (Gains) Losses			0.5	2.1
Income Tax (Expense) Benefit		(1.1)	(1.0)	(0.7)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Appalachian Power Co [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Interest Rate
Interest Expense	[2]	0.0	0.0	0.0
Pension and OPEB
Amortization of Prior Service Cost (Credit)		0.0	0.0	0.0
Amortization of Actuarial (Gains) Losses			0.0	0.0
Income Tax (Expense) Benefit		0.0	0.0	0.0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Appalachian Power Co [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Interest Rate
Interest Expense	[2]	(1.1)	(1.3)	(1.1)
Pension and OPEB
Amortization of Prior Service Cost (Credit)		0.0	0.0	0.0
Amortization of Actuarial (Gains) Losses			0.0	0.0
Income Tax (Expense) Benefit		(0.2)	(0.3)	(0.2)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Indiana Michigan Power Co [Member]
Interest Rate
Interest Expense	[2]	2.0	2.0	2.0
Pension and OPEB
Amortization of Prior Service Cost (Credit)		(0.8)	(0.8)	(0.8)
Amortization of Actuarial (Gains) Losses		0.7	0.7	0.6
Income Tax (Expense) Benefit		0.4	0.4	0.4
Reclassifications from Accumulated Other Comprehensive Income [Member] | Indiana Michigan Power Co [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Interest Rate
Interest Expense	[2]	0.0	0.0	0.0
Pension and OPEB
Amortization of Prior Service Cost (Credit)		(0.8)	(0.8)	(0.8)
Amortization of Actuarial (Gains) Losses		0.7	0.7	0.6
Income Tax (Expense) Benefit		0.0	0.0	0.0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Indiana Michigan Power Co [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Interest Rate
Interest Expense	[2]	0.0	0.0	0.0
Pension and OPEB
Amortization of Prior Service Cost (Credit)		0.0	0.0	0.0
Amortization of Actuarial (Gains) Losses		0.0	0.0	0.0
Income Tax (Expense) Benefit		0.0	0.0	0.0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Indiana Michigan Power Co [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Interest Rate
Interest Expense	[2]	2.0	2.0	2.0
Pension and OPEB
Amortization of Prior Service Cost (Credit)		0.0	0.0	0.0
Amortization of Actuarial (Gains) Losses		0.0	0.0	0.0
Income Tax (Expense) Benefit		0.4	0.4	0.4
Reclassifications from Accumulated Other Comprehensive Income [Member] | Ohio Power Co [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Interest Rate
Interest Expense	[2]	0.0	0.0	(1.3)
Pension and OPEB
Income Tax (Expense) Benefit		0.0	0.0	(0.3)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Public Service Co Of Oklahoma [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Interest Rate
Interest Expense	[2]	(0.1)	(1.3)	(1.3)
Pension and OPEB
Income Tax (Expense) Benefit		0.0	(0.3)	(0.3)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Southwestern Electric Power Co [Member]
Interest Rate
Interest Expense	[2]	1.9	1.9	1.9
Pension and OPEB
Amortization of Prior Service Cost (Credit)		(2.0)	(2.0)	(2.0)
Amortization of Actuarial (Gains) Losses		0.0	0.1	0.6
Income Tax (Expense) Benefit		0.0	0.0	0.1
Reclassifications from Accumulated Other Comprehensive Income [Member] | Southwestern Electric Power Co [Member] | Pension and OPEB [Member] | Amortization of Deferred Costs [Member]
Interest Rate
Interest Expense	[2]	0.0	0.0	0.0
Pension and OPEB
Amortization of Prior Service Cost (Credit)		(2.0)	(2.0)	(2.0)
Amortization of Actuarial (Gains) Losses		0.0	0.1	0.6
Income Tax (Expense) Benefit		(0.4)	(0.4)	(0.3)
Reclassifications from Accumulated Other Comprehensive Income [Member] | Southwestern Electric Power Co [Member] | Pension and OPEB [Member] | Changes in Funded Status [Member]
Interest Rate
Interest Expense	[2]	0.0	0.0	0.0
Pension and OPEB
Amortization of Prior Service Cost (Credit)		0.0	0.0	0.0
Amortization of Actuarial (Gains) Losses		0.0	0.0	0.0
Income Tax (Expense) Benefit		0.0	0.0	0.0
Reclassifications from Accumulated Other Comprehensive Income [Member] | Southwestern Electric Power Co [Member] | Interest Rate [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Interest Rate
Interest Expense	[2]	1.9	1.9	1.9
Pension and OPEB
Amortization of Prior Service Cost (Credit)		0.0	0.0	0.0
Amortization of Actuarial (Gains) Losses		0.0	0.0	0.0
Income Tax (Expense) Benefit		$ 0.4	$ 0.4	$ 0.4

[1] The change in fair value includes $(7) million, $6 million and $4 million related to AEP's investment in joint venture wind farms acquired as part of the purchase of Sempra Renewables LLC for the years ended December 31, 2021, 2020 and 2019, respectively. See “Sempra Renewables LLC” section of Note 17 for additional information.

[2] Amounts reclassified to the referenced line item on the statements of income.