Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Net Income (Loss)	$ 796.9	$ 748.2	$ 1,949.5	$ 1,762.0
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax	179.7	39.3	365.9	17.6
Amortization of Pension and OPEB Deferred Costs, Net of Tax	(2.0)	(1.8)	(6.1)	(5.3)
Other Comprehensive Income (Loss), Net of Tax, Total	177.7	37.5	359.8	12.3
TOTAL COMPREHENSIVE INCOME (LOSS)	974.6	785.7	2,309.3	1,774.3
Total Comprehensive Income (Loss) Attributable to Noncontrolling Interest	0.9	(0.4)	0.3	(2.6)
TOTAL COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO COMMON SHAREHOLDERS	973.7	786.1	2,309.0	1,776.9
Cash Flow Hedges, Tax	47.8	10.5	97.3	4.7
Amortization of Pension and OPEB Deferred Costs, Tax	$ (0.5)	$ (0.5)	(1.6)	(1.4)
Common Stock, Dividends Per Share, Declared	$ 0.74	$ 0.70
Appalachian Power Co [Member]
Net Income (Loss)	$ 86.3	$ 116.6	275.1	313.2
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax	(0.3)	0.6	8.5	(4.4)
Amortization of Pension and OPEB Deferred Costs, Net of Tax	(1.0)	(0.9)	(3.1)	(2.8)
Other Comprehensive Income (Loss), Net of Tax, Total	(1.3)	(0.3)	5.4	(7.2)
TOTAL COMPREHENSIVE INCOME (LOSS)	85.0	116.3	280.5	306.0
Cash Flow Hedges, Tax	0.0	0.1	2.3	(1.2)
Amortization of Pension and OPEB Deferred Costs, Tax	(0.2)	(0.3)	(0.8)	(0.8)
AEP Texas Inc. [Member]
Net Income (Loss)	99.5	82.6	225.4	197.1
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax	0.3	0.3	0.8	0.8
Amortization of Pension and OPEB Deferred Costs, Net of Tax	0.0	0.0	0.1	0.1
Other Comprehensive Income (Loss), Net of Tax, Total	0.3	0.3	0.9	0.9
TOTAL COMPREHENSIVE INCOME (LOSS)	99.8	82.9	226.3	198.0
Cash Flow Hedges, Tax	0.1	0.1	0.2	0.2
Amortization of Pension and OPEB Deferred Costs, Tax	0.0	0.0	0.0	0.0
Indiana Michigan Power Co [Member]
Net Income (Loss)	104.1	76.7	232.1	232.8
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax	0.4	0.4	1.3	1.2
Amortization of Pension and OPEB Deferred Costs, Net of Tax	0.0	(0.1)	(0.1)	(0.1)
Other Comprehensive Income (Loss), Net of Tax, Total	0.4	0.3	1.2	1.1
TOTAL COMPREHENSIVE INCOME (LOSS)	104.5	77.0	233.3	233.9
Cash Flow Hedges, Tax	0.1	0.1	0.3	0.3
Amortization of Pension and OPEB Deferred Costs, Tax	0.0	0.0	0.0	0.0
Ohio Power Co [Member]
Net Income (Loss)	56.4	59.0	198.6	215.0
Public Service Co Of Oklahoma [Member]
Net Income (Loss)	93.2	80.3	136.6	116.4
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax	0.0	(0.3)	(0.1)	(0.8)
Other Comprehensive Income (Loss), Net of Tax, Total		(0.3)
TOTAL COMPREHENSIVE INCOME (LOSS)	93.2	80.0	136.5	115.6
Cash Flow Hedges, Tax	0.0	0.0	0.0	(0.2)
Southwestern Electric Power Co [Member]
Net Income (Loss)	109.9	88.6	210.7	163.9
OTHER COMPREHENSIVE INCOME
Cash Flow Hedges, Net of Tax	0.3	0.4	1.1	1.1
Amortization of Pension and OPEB Deferred Costs, Net of Tax	(0.4)	(0.4)	(1.2)	(1.1)
Other Comprehensive Income (Loss), Net of Tax, Total	(0.1)	0.0	(0.1)	0.0
TOTAL COMPREHENSIVE INCOME (LOSS)	109.8	88.6	210.6	163.9
Total Comprehensive Income (Loss) Attributable to Noncontrolling Interest	1.0	0.7	2.6	2.1
TOTAL COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO COMMON SHAREHOLDERS	108.8	87.9	208.0	161.8
Cash Flow Hedges, Tax	0.1	0.1	0.3	0.3
Amortization of Pension and OPEB Deferred Costs, Tax	(0.1)	(0.1)	(0.3)	(0.3)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
OTHER COMPREHENSIVE INCOME
Other Comprehensive Income (Loss), Net of Tax, Total	(2.0)	(1.8)	(6.1)	(5.3)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | Appalachian Power Co [Member]
OTHER COMPREHENSIVE INCOME
Other Comprehensive Income (Loss), Net of Tax, Total	(1.0)	(0.9)	(3.1)	(2.8)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | AEP Texas Inc. [Member]
OTHER COMPREHENSIVE INCOME
Other Comprehensive Income (Loss), Net of Tax, Total	0.0	0.0	0.1	0.1
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | Indiana Michigan Power Co [Member]
OTHER COMPREHENSIVE INCOME
Other Comprehensive Income (Loss), Net of Tax, Total	0.0	(0.1)	(0.1)	(0.1)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | Southwestern Electric Power Co [Member]
OTHER COMPREHENSIVE INCOME
Other Comprehensive Income (Loss), Net of Tax, Total	$ (0.4)	$ (0.4)	$ (1.2)	$ (1.1)