Income Taxes (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Federal:
Current		$ (116.7)	$ 113.1	$ (27.8)
Deferred		115.9	(88.8)	182.6
Total Federal		(0.8)	24.3	154.8
Current		69.0	26.6	6.0
Deferred		(13.6)	(45.5)	(45.3)
Total State and Local		55.4	(18.9)	(39.3)
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)		54.6	5.4	115.5
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income		2,212.6	2,305.6	2,488.1
Less: Equity Earnings		(58.5)	109.4	(91.7)
Income Tax Expense (Benefit)		54.6	5.4	115.5
Pretax Income		2,265.8	2,309.6	2,600.2
Income Taxes on Pretax Income at Statutory Rate (21%)		$ 475.8	$ 485.0	$ 546.0
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	21.00%	21.00%
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation		$ 26.0	$ 17.1	$ 25.9
Investment Tax Credit Amortization		(50.3)	(14.3)	(22.0)
Production Tax Credits		(175.2)	(197.1)	(98.8)
State and Local Income Taxes, Net		43.7	(14.0)	39.4
Removal Costs		(22.0)	(26.5)	(20.0)
AFUDC		(39.8)	(29.3)	(30.6)
Effective Income Tax Rate Reconciliation, Parent Company Loss Benefit				0.0
Increase Decrease in Income Taxes Due to Tax Reserve Adjustments	[1]			(55.1)
Tax Reform Excess ADIT Reversal		(151.1)	(214.5)	(255.6)
Remeasurement of Excess ADIT		(46.0)
Federal Return to Provision		0.0	(17.4)	(1.6)
Disallowance Cost		0.0
Other		(6.5)	16.4	(12.1)
Income Tax Expense (Benefit)		$ 54.6	$ 5.4	$ 115.5
Effective Income Tax Rate		2.40%	0.20%	4.40%
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets		$ 3,216.1	$ 3,567.4
Deferred Tax Liabilities		(12,631.8)	(12,464.3)
Property Related Temporary Differences		(7,779.7)	(7,788.1)
Amounts Due from Customers for Future Federal Income Taxes		900.1	962.7
Deferred State Income Taxes		(1,222.8)	(1,049.3)
Securitized Assets		(79.9)	(98.9)
Regulatory Assets		(768.9)	(865.2)
Accrued Nuclear Decommissioning		(776.5)	(632.7)
Net Operating Loss Carryforward		148.0	132.4
Deferred Tax Assets, Tax Credit Carryforwards [Abstract]
Tax Credit Carryforward		321.9	612.0
Operating Lease Liability		131.1	142.9
Investment in Partnership		(293.1)	(338.9)
All Other, Net		4.1	44.8
Net Deferred Tax Liabilities		(9,415.7)	(8,896.9)
Tax Contingency [Abstract]
Unrecognized Tax Benefits, if Recognized - Amount		13.0	23.0	$ 14.0
Income Taxes (Textuals) [Abstract]
Valuation Allowance			(28.2)
Income Tax Expense (Benefit)		54.6	5.4	115.5
Operating Income (Loss)		$ (3,556.2)	(3,482.7)	(3,411.3)
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
corporate alternative minimum tax		15.00%
Production Tax Credit Proceeds		$ 102.0
Deferred Revenue			7.1
Liability, Retirement and Postemployment Benefits			2.5
Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date		Dec. 31, 2036
Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date		Dec. 31, 2041
AEP Texas Inc. [Member]
Federal:
Current		$ 19.8	29.0	(1.2)
Deferred		63.5	41.4	40.5
Total Federal		83.3	70.4	39.3
Current		2.7	2.2	3.0
Deferred		(0.1)	0.0	0.8
Total State and Local		2.6	2.2	3.8
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)		85.9	72.6	43.1
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income		370.4	307.9	289.8
Income Tax Expense (Benefit)		85.9	72.6	43.1
Pretax Income		456.3	380.5	332.9
Income Taxes on Pretax Income at Statutory Rate (21%)		95.8	79.9	69.9
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation		0.6	0.0	0.0
Investment Tax Credit Amortization		(0.7)	0.0	0.0
Production Tax Credits		0.0	0.0	0.0
State and Local Income Taxes, Net		2.1	1.7	2.4
Removal Costs		0.0	0.0	0.0
AFUDC		(6.0)	(4.1)	(4.5)
Effective Income Tax Rate Reconciliation, Parent Company Loss Benefit				(3.2)
Increase Decrease in Income Taxes Due to Tax Reserve Adjustments				0.0
Tax Reform Excess ADIT Reversal		(6.0)	(5.5)	(21.3)
Remeasurement of Excess ADIT		0.0
Federal Return to Provision		(0.1)	0.0	0.0
Disallowance Cost		0.0
Other		0.2	0.6	(0.2)
Income Tax Expense (Benefit)		$ 85.9	$ 72.6	$ 43.1
Effective Income Tax Rate		18.80%	19.10%	12.90%
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets		$ 173.6	$ 177.0
Deferred Tax Liabilities		(1,401.4)	(1,321.2)
Property Related Temporary Differences		(1,227.1)	(1,130.7)
Amounts Due from Customers for Future Federal Income Taxes		109.3	111.0
Deferred State Income Taxes		(41.5)	(36.6)
Securitized Assets		(45.6)	(65.0)
Regulatory Assets		(57.6)	(48.9)
Accrued Nuclear Decommissioning		0.0	0.0
Net Operating Loss Carryforward		0.0	0.0
Deferred Tax Assets, Tax Credit Carryforwards [Abstract]
Tax Credit Carryforward		13.7	0.0
Operating Lease Liability		16.6	20.3
Investment in Partnership		0.0	0.0
All Other, Net		4.4	5.7
Net Deferred Tax Liabilities		(1,227.8)	(1,144.2)
Income Taxes (Textuals) [Abstract]
Valuation Allowance			0.0
Income Tax Expense (Benefit)		85.9	72.6	$ 43.1
Operating Income (Loss)		$ (639.1)	(549.2)	(476.0)
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Deferred Revenue			0.0
Liability, Retirement and Postemployment Benefits			0.0
AEP Texas Inc. [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date		Dec. 31, 2036
AEP Texas Inc. [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date		Dec. 31, 2041
AEP Transmission Co [Member]
Federal:
Current		$ 93.9	98.0	69.8
Deferred		52.3	46.0	54.1
Total Federal		146.2	144.0	123.9
Current		9.1	8.8	5.8
Deferred		(8.2)	16.3	14.4
Total State and Local		0.9	25.1	20.2
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)		147.1	169.1	144.1
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income		614.2	594.2	591.7
Income Tax Expense (Benefit)		147.1	169.1	144.1
Pretax Income		761.3	763.3	735.8
Income Taxes on Pretax Income at Statutory Rate (21%)		159.9	160.3	154.5
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation		2.4	0.0	0.0
Investment Tax Credit Amortization		0.0	0.0	0.0
Production Tax Credits		0.0	0.0	0.0
State and Local Income Taxes, Net		0.7	19.8	19.8
Removal Costs		0.0	0.0	0.0
AFUDC		(17.5)	(14.8)	(14.1)
Effective Income Tax Rate Reconciliation, Parent Company Loss Benefit				(18.3)
Increase Decrease in Income Taxes Due to Tax Reserve Adjustments				0.0
Tax Reform Excess ADIT Reversal		1.7	0.0	0.0
Remeasurement of Excess ADIT		0.0
Federal Return to Provision		0.0	0.0	0.0
Disallowance Cost		0.0
Other		(0.1)	3.8	2.2
Income Tax Expense (Benefit)		$ 147.1	$ 169.1	$ 144.1
Effective Income Tax Rate		19.30%	22.20%	19.60%
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets		$ 188.1	$ 165.0
Deferred Tax Liabilities		(1,335.8)	(1,221.5)
Property Related Temporary Differences		(1,134.6)	(1,081.5)
Amounts Due from Customers for Future Federal Income Taxes		119.0	118.5
Deferred State Income Taxes		(155.4)	(108.1)
Securitized Assets		0.0	0.0
Regulatory Assets		(7.6)	(1.1)
Accrued Nuclear Decommissioning		0.0	0.0
Net Operating Loss Carryforward		3.9	5.5
Deferred Tax Assets, Tax Credit Carryforwards [Abstract]
Tax Credit Carryforward		0.0	0.2
Operating Lease Liability		0.3	0.3
Investment in Partnership		0.0	0.0
All Other, Net		26.7	9.8
Net Deferred Tax Liabilities		(1,147.7)	(1,056.5)
Income Taxes (Textuals) [Abstract]
Valuation Allowance			(0.1)
Income Tax Expense (Benefit)		147.1	169.1	$ 144.1
Operating Income (Loss)		$ (865.6)	(853.7)	(809.3)
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Deferred Revenue			0.0
Liability, Retirement and Postemployment Benefits			0.0
AEP Transmission Co [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date		Dec. 31, 2036
AEP Transmission Co [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date		Dec. 31, 2041
Appalachian Power Co [Member]
Federal:
Current		$ 62.2	(61.0)	5.0
Deferred		(60.5)	86.6	14.9
Total Federal		1.7	25.6	19.9
Current		6.3	(0.4)	2.2
Deferred		6.2	(7.0)	0.0
Total State and Local		12.5	(7.4)	2.2
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)		14.2	18.2	22.1
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income		294.4	394.2	348.9
Income Tax Expense (Benefit)		14.2	18.2	22.1
Pretax Income		308.6	412.4	371.0
Income Taxes on Pretax Income at Statutory Rate (21%)		64.8	86.6	77.9
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation		9.9	4.7	11.7
Investment Tax Credit Amortization		0.0	0.0	0.0
Production Tax Credits		(0.1)	0.0	0.0
State and Local Income Taxes, Net		9.9	(5.9)	2.1
Removal Costs		(5.1)	(9.8)	(7.3)
AFUDC		(5.5)	(3.7)	(4.6)
Effective Income Tax Rate Reconciliation, Parent Company Loss Benefit				0.0
Increase Decrease in Income Taxes Due to Tax Reserve Adjustments	[1]			4.5
Tax Reform Excess ADIT Reversal		(17.3)	(50.9)	(60.5)
Remeasurement of Excess ADIT		(46.0)
Federal Return to Provision		3.4	(2.8)	(1.6)
Disallowance Cost		0.0
Other		0.2	0.0	(0.1)
Income Tax Expense (Benefit)		$ 14.2	$ 18.2	$ 22.1
Effective Income Tax Rate		4.60%	4.40%	6.00%
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets		$ 473.0	$ 510.3
Deferred Tax Liabilities		(2,484.9)	(2,502.5)
Property Related Temporary Differences		(1,556.0)	(1,509.8)
Amounts Due from Customers for Future Federal Income Taxes		143.4	163.0
Deferred State Income Taxes		(308.4)	(318.5)
Securitized Assets		(29.2)	(33.9)
Regulatory Assets		(257.4)	(301.2)
Accrued Nuclear Decommissioning		0.0	0.0
Net Operating Loss Carryforward		0.0	0.0
Deferred Tax Assets, Tax Credit Carryforwards [Abstract]
Tax Credit Carryforward		0.1	0.0
Operating Lease Liability		15.1	15.6
Investment in Partnership		(0.1)	0.0
All Other, Net		(19.4)	(7.4)
Net Deferred Tax Liabilities		(2,011.9)	(1,992.2)
Income Taxes (Textuals) [Abstract]
Valuation Allowance			0.0
Income Tax Expense (Benefit)		14.2	18.2	$ 22.1
Operating Income (Loss)		$ (531.0)	(602.1)	(549.4)
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Deferred Revenue			0.0
Liability, Retirement and Postemployment Benefits			0.0
Appalachian Power Co [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date		Dec. 31, 2036
Appalachian Power Co [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date		Dec. 31, 2041
Indiana Michigan Power Co [Member]
Federal:
Current		$ 93.2	43.4	26.9
Deferred		(56.9)	(51.3)	(35.5)
Total Federal		36.3	(7.9)	(8.6)
Current		21.1	10.9	(0.6)
Deferred		1.2	1.2	(1.4)
Total State and Local		22.3	12.1	(2.0)
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)		58.6	4.2	(10.6)
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income		335.9	324.7	279.8
Income Tax Expense (Benefit)		58.6	4.2	(10.6)
Pretax Income		394.5	328.9	269.2
Income Taxes on Pretax Income at Statutory Rate (21%)		82.8	69.1	56.5
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation		6.4	2.9	3.5
Investment Tax Credit Amortization		(1.6)	(3.1)	(6.4)
Production Tax Credits		0.0	0.0	0.0
State and Local Income Taxes, Net		17.5	9.6	(1.3)
Removal Costs		(11.8)	(12.4)	(9.7)
AFUDC		(2.3)	(2.1)	(2.7)
Effective Income Tax Rate Reconciliation, Parent Company Loss Benefit				(2.8)
Increase Decrease in Income Taxes Due to Tax Reserve Adjustments				0.0
Tax Reform Excess ADIT Reversal		(30.0)	(54.0)	(46.3)
Remeasurement of Excess ADIT		0.0
Federal Return to Provision		(2.5)	(6.2)	(0.6)
Disallowance Cost		0.0
Other		0.1	0.4	(0.8)
Income Tax Expense (Benefit)		$ 58.6	$ 4.2	$ (10.6)
Effective Income Tax Rate		14.90%	1.30%	(3.90%)
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets		$ 1,014.1	$ 933.7
Deferred Tax Liabilities		(2,184.0)	(2,090.7)
Property Related Temporary Differences		(298.1)	(398.0)
Amounts Due from Customers for Future Federal Income Taxes		103.2	114.3
Deferred State Income Taxes		(238.1)	(227.0)
Securitized Assets		0.0	0.0
Regulatory Assets		32.3	(29.5)
Accrued Nuclear Decommissioning		(776.5)	(632.7)
Net Operating Loss Carryforward		0.0	0.0
Deferred Tax Assets, Tax Credit Carryforwards [Abstract]
Tax Credit Carryforward		7.2	0.0
Operating Lease Liability		10.8	13.6
Investment in Partnership		0.0	0.0
All Other, Net		(10.7)	2.3
Net Deferred Tax Liabilities		(1,169.9)	(1,157.0)
Income Taxes (Textuals) [Abstract]
Valuation Allowance			0.0
Income Tax Expense (Benefit)		58.6	4.2	$ (10.6)
Operating Income (Loss)		$ (487.7)	(419.9)	(357.9)
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Deferred Revenue			0.0
Liability, Retirement and Postemployment Benefits			0.0
Indiana Michigan Power Co [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date		Dec. 31, 2036
Indiana Michigan Power Co [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date		Dec. 31, 2041
Ohio Power Co [Member]
Federal:
Current		$ 46.6	(27.0)	6.8
Deferred		2.8	73.3	25.2
Total Federal		49.4	46.3	32.0
Current		(0.3)	(0.3)	(3.1)
Deferred		5.2	(1.8)	5.5
Total State and Local		4.9	(2.1)	2.4
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)		54.3	44.2	34.4
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income		328.2	287.8	253.6
Less: Equity Earnings		0.0	(0.6)	0.0
Income Tax Expense (Benefit)		54.3	44.2	34.4
Pretax Income		382.5	331.4	288.0
Income Taxes on Pretax Income at Statutory Rate (21%)		80.3	69.6	60.5
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation		2.6	3.0	2.2
Investment Tax Credit Amortization		0.0	0.0	0.0
Production Tax Credits		0.0	0.0	0.0
State and Local Income Taxes, Net		3.9	(1.6)	0.0
Removal Costs		0.0	0.0	0.0
AFUDC		(3.6)	(2.9)	(2.3)
Effective Income Tax Rate Reconciliation, Parent Company Loss Benefit				0.0
Increase Decrease in Income Taxes Due to Tax Reserve Adjustments	[1]			8.9
Tax Reform Excess ADIT Reversal		(28.9)	(27.5)	(32.6)
Remeasurement of Excess ADIT		0.0
Federal Return to Provision		(0.4)	3.5	(1.2)
Disallowance Cost		0.0
Other		0.4	0.1	(1.1)
Income Tax Expense (Benefit)		$ 54.3	$ 44.2	$ 34.4
Effective Income Tax Rate		14.20%	13.30%	11.90%
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets		$ 271.4	$ 218.8
Deferred Tax Liabilities		(1,424.1)	(1,319.9)
Property Related Temporary Differences		(1,162.1)	(1,133.8)
Amounts Due from Customers for Future Federal Income Taxes		104.5	112.6
Deferred State Income Taxes		(68.8)	(59.6)
Securitized Assets		(5.1)	0.0
Regulatory Assets		(83.5)	(57.6)
Accrued Nuclear Decommissioning		0.0	0.0
Net Operating Loss Carryforward		2.6	0.0
Deferred Tax Assets, Tax Credit Carryforwards [Abstract]
Tax Credit Carryforward		41.0	0.0
Operating Lease Liability		14.6	15.5
Investment in Partnership		(0.7)	0.0
All Other, Net		4.8	21.8
Net Deferred Tax Liabilities		(1,152.7)	(1,101.1)
Income Taxes (Textuals) [Abstract]
Valuation Allowance			0.0
Income Tax Expense (Benefit)		54.3	44.2	$ 34.4
Operating Income (Loss)		$ (469.9)	(413.7)	(385.2)
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Deferred Revenue			0.0
Liability, Retirement and Postemployment Benefits			0.0
Ohio Power Co [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date		Dec. 31, 2036
Ohio Power Co [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date		Dec. 31, 2041
Public Service Co Of Oklahoma [Member]
Federal:
Current		$ (60.8)	(3.3)	(109.6)
Deferred		2.9	(50.5)	105.6
Total Federal		(57.9)	(53.8)	(4.0)
Current		0.3	0.0	0.0
Deferred		4.0	4.6	8.1
Total State and Local		4.3	4.6	8.1
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)		(53.6)	(49.2)	4.1
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income		208.8	167.6	141.1
Income Tax Expense (Benefit)		(53.6)	(49.2)	4.1
Pretax Income		155.2	118.4	145.2
Income Taxes on Pretax Income at Statutory Rate (21%)		32.6	24.9	30.5
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation		0.4	0.0	0.0
Investment Tax Credit Amortization		(1.4)	(1.6)	(1.8)
Production Tax Credits		(64.3)	(47.7)	(6.0)
State and Local Income Taxes, Net		3.5	4.3	6.4
Removal Costs		0.0	0.0	0.0
AFUDC		(1.8)	0.0	0.0
Effective Income Tax Rate Reconciliation, Parent Company Loss Benefit				0.0
Increase Decrease in Income Taxes Due to Tax Reserve Adjustments				0.0
Tax Reform Excess ADIT Reversal		(23.3)	(25.4)	(25.4)
Remeasurement of Excess ADIT		0.0
Federal Return to Provision		0.6	(3.7)	0.7
Disallowance Cost		0.0
Other		0.1	0.0	(0.3)
Income Tax Expense (Benefit)		$ (53.6)	$ (49.2)	$ 4.1
Effective Income Tax Rate		(34.50%)	(41.60%)	2.80%
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets		$ 282.3	$ 225.0
Deferred Tax Liabilities		(1,113.5)	(1,013.6)
Property Related Temporary Differences		(817.2)	(763.3)
Amounts Due from Customers for Future Federal Income Taxes		88.6	96.0
Deferred State Income Taxes		(122.6)	(81.9)
Securitized Assets		0.0	0.0
Regulatory Assets		(83.8)	(140.2)
Accrued Nuclear Decommissioning		0.0	0.0
Net Operating Loss Carryforward		25.3	25.8
Deferred Tax Assets, Tax Credit Carryforwards [Abstract]
Tax Credit Carryforward		53.8	54.3
Operating Lease Liability		23.6	0.0
Investment in Partnership		0.0	0.0
All Other, Net		1.1	20.7
Net Deferred Tax Liabilities		(831.2)	(788.6)
Income Taxes (Textuals) [Abstract]
Valuation Allowance			0.0
Income Tax Expense (Benefit)		(53.6)	(49.2)	$ 4.1
Operating Income (Loss)		$ (234.3)	(180.8)	(192.9)
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Deferred Revenue			0.0
Liability, Retirement and Postemployment Benefits			0.0
Public Service Co Of Oklahoma [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date		Dec. 31, 2036
Public Service Co Of Oklahoma [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date		Dec. 31, 2041
Southwestern Electric Power Co [Member]
Federal:
Current		$ (88.1)	(32.3)	(16.7)
Deferred		59.9	13.4	26.2
Total Federal		(28.2)	(18.9)	9.5
Current		1.0	(1.8)	0.4
Deferred		(6.1)	(4.5)	(10.5)
Total State and Local		(5.1)	(6.3)	(10.1)
Income Tax Expense (Benefit):
Income Tax Expense (Benefit)		(33.3)	(25.2)	(0.6)
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Net Income		223.8	294.3	242.1
Less: Equity Earnings		(1.4)	(1.4)	(3.4)
Income Tax Expense (Benefit)		(33.3)	(25.2)	(0.6)
Pretax Income		189.1	267.7	238.1
Income Taxes on Pretax Income at Statutory Rate (21%)		39.7	56.2	50.0
Reconciliation of Federal Statutory Rate and Amount of Taxes Reported
Depreciation		2.1	2.3	1.8
Investment Tax Credit Amortization		(0.2)	0.0	0.0
Production Tax Credits		(67.1)	(57.1)	(7.2)
State and Local Income Taxes, Net		(4.0)	(4.9)	(8.0)
Removal Costs		0.0	0.0	0.0
AFUDC		(2.4)	0.0	0.0
Effective Income Tax Rate Reconciliation, Parent Company Loss Benefit				0.0
Increase Decrease in Income Taxes Due to Tax Reserve Adjustments				0.0
Tax Reform Excess ADIT Reversal		(12.6)	(14.8)	(31.1)
Remeasurement of Excess ADIT		0.0
Federal Return to Provision		1.0	0.0	0.0
Disallowance Cost		12.0
Other		(1.8)	(6.9)	(6.1)
Income Tax Expense (Benefit)		$ (33.3)	$ (25.2)	$ (0.6)
Effective Income Tax Rate		(17.60%)	(9.40%)	(0.30%)
Net Deferred Tax Liability and Significant Temporary Differences
Deferred Tax Assets		$ 441.5	$ 374.9
Deferred Tax Liabilities		(1,620.8)	(1,464.6)
Property Related Temporary Differences		(1,087.2)	(1,053.8)
Amounts Due from Customers for Future Federal Income Taxes		142.5	146.2
Deferred State Income Taxes		(238.6)	(208.7)
Securitized Assets		0.0	0.0
Regulatory Assets		(143.4)	(114.1)
Accrued Nuclear Decommissioning		0.0	0.0
Net Operating Loss Carryforward		47.5	42.7
Deferred Tax Assets, Tax Credit Carryforwards [Abstract]
Tax Credit Carryforward		68.6	66.0
Operating Lease Liability		26.3	0.0
Investment in Partnership		(1.3)	0.0
All Other, Net		6.3	32.0
Net Deferred Tax Liabilities		(1,179.3)	(1,089.7)
Income Taxes (Textuals) [Abstract]
Valuation Allowance			0.0
Income Tax Expense (Benefit)		(33.3)	(25.2)	$ (0.6)
Operating Income (Loss)		$ (292.3)	(370.0)	(339.5)
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Deferred Revenue			0.0
Liability, Retirement and Postemployment Benefits			0.0
Southwestern Electric Power Co [Member] | Minimum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date		Dec. 31, 2036
Southwestern Electric Power Co [Member] | Maximum [Member]
Income Taxes (Textuals) [Abstract]
Tax Credit Carryforward, Expiration Date		Dec. 31, 2041
Arkansas
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward		$ 259.3
Arkansas | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2024
Arkansas | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2033
Arkansas | Southwestern Electric Power Co [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2024
Arkansas | Southwestern Electric Power Co [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2033
Kentucky
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward		$ 204.1
Kentucky | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2030
Kentucky | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2037
Louisiana
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward		$ 629.2
Louisiana | Southwestern Electric Power Co [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward		619.1
Oklahoma
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward		$ 877.9
Oklahoma | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2037
Oklahoma | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2037
Oklahoma | Public Service Co Of Oklahoma [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward		$ 947.1
Oklahoma | Public Service Co Of Oklahoma [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2037
Oklahoma | Public Service Co Of Oklahoma [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2037
Tennessee
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward		$ 47.7
Tennessee | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2032
Tennessee | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2038
Ohio Municipal
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward		$ 1,954.8
Ohio Municipal | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2024
Ohio Municipal | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2028
Ohio Municipal | Ohio Power Co [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward		$ 152.3
Ohio Municipal | Ohio Power Co [Member] | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2024
Ohio Municipal | Ohio Power Co [Member] | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2028
Colorado
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward		$ 80.8
Pennsylvania | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2030
Pennsylvania | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2043
Illinois
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward		$ 54.4
Federal
Tax Credit Carryforward
Tax Credit Carryforward, Amount		321.9
Federal | AEP Texas Inc. [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount		13.7
Federal | Appalachian Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount		0.1
Federal | Indiana Michigan Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount		7.2
Federal | Ohio Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount		41.0
Federal | Public Service Co Of Oklahoma [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount		53.8
Federal | Southwestern Electric Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount		68.6
State and Local Jurisdiction
Tax Credit Carryforward
Tax Credit Carryforward, Amount		40.0
State and Local Jurisdiction | AEP Texas Inc. [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount		0.0
State and Local Jurisdiction | Appalachian Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount		0.0
State and Local Jurisdiction | Indiana Michigan Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount		0.0
State and Local Jurisdiction | Ohio Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount		0.0
State and Local Jurisdiction | Public Service Co Of Oklahoma [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount		40.0
State and Local Jurisdiction | Southwestern Electric Power Co [Member]
Tax Credit Carryforward
Tax Credit Carryforward, Amount		0.0
MICHIGAN
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward		$ 45.6
MICHIGAN | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2030
MICHIGAN | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2032
PENNSYLVANIA
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward		$ 47.8
ILLINOIS | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2039
ILLINOIS | Maximum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2041
Arkansas | Southwestern Electric Power Co [Member]
Net Income Tax Operating Loss Carryforwards
Net Income Tax Operating Loss Carryforward		$ 258.9
COLORADO | Minimum [Member]
Net Income Tax Operating Loss Carryforwards
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2041
Dolet Hills Lignite Co, LLC [Member]
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Less: Equity Earnings		$ (1.4)	(1.4)	(3.4)
Dolet Hills Lignite Co, LLC [Member] | Southwestern Electric Power Co [Member]
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Less: Equity Earnings		(1.4)	(1.4)	(3.4)
Investment funds | AEP Texas Inc. [Member]
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Less: Equity Earnings		0.0	0.0	0.0
Investment funds | AEP Transmission Co [Member]
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Less: Equity Earnings		0.0	0.0	0.0
Investment funds | Appalachian Power Co [Member]
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Less: Equity Earnings		0.0	0.0	0.0
Investment funds | Indiana Michigan Power Co [Member]
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Less: Equity Earnings		0.0	0.0	0.0
Investment funds | Ohio Power Co [Member]
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Less: Equity Earnings		0.0	(0.6)	0.0
Investment funds | Public Service Co Of Oklahoma [Member]
Reconciliation of Federal Income Taxes and Amount of Income Tax Reported
Less: Equity Earnings		$ 0.0	$ 0.0	$ 0.0

[1] 2021 amount represents an out of period adjustment related to Deferred Income Taxes and Income Tax Expense (Benefit). Management concluded the misstatement and subsequent correction was not material to the 2021 or prior period financial statements.