Benefit Plans 1 (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		$ 4,398.3	$ 3,852.3
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		(601.3)	(728.0)
AEP Texas Inc. [Member]
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		211.3	192.1
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		(73.8)	(57.2)
Appalachian Power Co [Member]
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		129.2	121.7
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		(34.6)	(49.6)
Indiana Michigan Power Co [Member]
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		316.5	237.6
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		(58.3)	(69.2)
Ohio Power Co [Member]
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		601.1	524.2
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		(29.2)	(40.0)
Public Service Co Of Oklahoma [Member]
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		7.9	6.0
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		(19.4)	(20.6)
Southwestern Electric Power Co [Member]
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		251.8	234.8
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		$ (63.0)	$ (95.2)
Pension Plans [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.90%	2.50%
Interest Crediting Rate		4.00%	4.00%
Rate of Compensation Increase	[1]	5.10%	5.00%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		2.50%	3.25%	4.30%
Interest Crediting Rate		4.00%	4.00%	4.00%
Expected Return on Plan Assets		4.75%	5.75%	6.25%
Rate of Compensation Increase	[2]	5.10%	5.00%	4.95%
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 5,544.5	$ 5,236.8
Service Cost		129.2	111.9	$ 95.5
Interest Cost		137.2	167.9	204.4
Actuarial (Gain) Loss		(173.9)	434.7
Plan Amendments		0.0	0.0
Benefit Payments		(450.0)	(406.8)
Participant Contributions		0.0	0.0
Medicare Subsidy		0.0	0.0
Benefit Obligation as of December 31		5,187.0	5,544.5	5,236.8
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		5,556.6	5,015.4
Actual Gain (Loss) on Plan Assets		239.2	832.4
Company Contributions	[3]	7.1	115.6
Participant Contributions		0.0	0.0
Benefit Payments		(450.0)	(406.8)
Fair Value of Plan Assets as of December 31		5,352.9	5,556.6	$ 5,015.4
Funded (Underfunded) Status as of December 31		165.9	12.1
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		244.3	93.5
Other Current Liabilities - Accrued Short-term Benefit Liability		(7.6)	(6.7)
Employee Benefits and Pension Obligations - Accrued Long-term Benefit Liability		(70.8)	(74.7)
Funded (Underfunded) Status		165.9	12.1
Components
Net Actuarial Loss		894.7	1,179.6
Prior Service Cost (Credit)		0.2	0.2
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(183.4)	(132.9)
Amortization of Actuarial Gain (Loss)		(101.5)	(93.7)
Prior Service (Credit) Cost		0.0	0.0
Amortization of Prior Service Credit (Cost)		0.0	0.0
Change for the Year		$ (284.9)	$ (226.6)
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	[1]	5.10%	5.00%
Company Contributions	[3]	$ 7.1	$ 115.6
Pension Plans [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		878.0	1,182.4
Pension Plans [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		3.6	(0.5)
Pension Plans [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		$ 13.3	$ (2.1)
Pension Plans [Member] | AEP Texas Inc. [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.90%	2.50%
Interest Crediting Rate		4.00%	4.00%
Rate of Compensation Increase	[1]	5.10%	5.05%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		2.50%	3.25%	4.30%
Interest Crediting Rate		4.00%	4.00%	4.00%
Expected Return on Plan Assets		4.75%	5.75%	6.25%
Rate of Compensation Increase	[2]	5.10%	5.05%	5.00%
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 453.2	$ 441.2
Service Cost		11.8	10.0	$ 8.6
Interest Cost		11.2	13.9	17.5
Actuarial (Gain) Loss		(10.9)	28.1
Plan Amendments		0.0	0.0
Benefit Payments		(45.5)	(40.0)
Participant Contributions		0.0	0.0
Benefit Obligation as of December 31		419.8	453.2	441.2
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		474.0	435.1
Actual Gain (Loss) on Plan Assets		16.0	67.2
Company Contributions		0.4	11.7
Participant Contributions		0.0	0.0
Benefit Payments		(45.5)	(40.0)
Fair Value of Plan Assets as of December 31		444.9	474.0	$ 435.1
Funded (Underfunded) Status as of December 31		25.1	20.8
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		28.7	24.7
Other Current Liabilities - Accrued Short-term Benefit Liability		(0.3)	(0.4)
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		(3.3)	(3.5)
Funded (Underfunded) Status		25.1	20.8
Components
Net Actuarial Loss		144.7	160.5
Prior Service Cost (Credit)		0.0	0.0
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(7.5)	(16.4)
Amortization of Actuarial Gain (Loss)		(8.3)	(7.8)
Prior Service (Credit) Cost		0.0	0.0
Amortization of Prior Service Credit (Cost)		0.0	0.0
Change for the Year		$ (15.8)	$ (24.2)
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	[1]	5.10%	5.05%
Company Contributions		$ 0.4	$ 11.7
Pension Plans [Member] | AEP Texas Inc. [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		136.7	151.3
Pension Plans [Member] | AEP Texas Inc. [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		1.8	2.0
Pension Plans [Member] | AEP Texas Inc. [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		$ 6.2	$ 7.2
Pension Plans [Member] | Appalachian Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.90%	2.50%
Interest Crediting Rate		4.00%	4.00%
Rate of Compensation Increase	[1]	4.85%	4.85%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		2.50%	3.25%	4.30%
Interest Crediting Rate		4.00%	4.00%	4.00%
Expected Return on Plan Assets		4.75%	5.75%	6.25%
Rate of Compensation Increase	[2]	4.85%	4.85%	4.75%
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 670.8	$ 647.2
Service Cost		11.9	10.5	$ 9.4
Interest Cost		16.4	20.3	25.2
Actuarial (Gain) Loss		(28.5)	40.0
Plan Amendments		0.0	0.0
Benefit Payments		(48.9)	(47.2)
Participant Contributions		0.0	0.0
Medicare Subsidy		0.0	0.0
Benefit Obligation as of December 31		621.7	670.8	647.2
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		701.3	637.0
Actual Gain (Loss) on Plan Assets		30.9	104.5
Company Contributions		0.0	7.0
Participant Contributions		0.0	0.0
Benefit Payments		(48.9)	(47.2)
Fair Value of Plan Assets as of December 31		683.3	701.3	$ 637.0
Funded (Underfunded) Status as of December 31		61.6	30.5
Benefit Amounts Recognized on the Balance Sheets
Employee Benefits and Pension Assets - Prepaid Benefit Costs		62.4	31.0
Other Current Liabilities - Accrued Short-term Benefit Liability		0.0	0.0
Employee Benefits and Pension Obligations - Accrued Long-term Benefit Liability		(0.8)	(0.5)
Funded (Underfunded) Status		61.6	30.5
Components
Net Actuarial Loss		83.9	126.3
Prior Service Cost (Credit)		0.0	0.0
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(30.4)	(30.8)
Amortization of Actuarial Gain (Loss)		(12.0)	(11.2)
Prior Service (Credit) Cost		0.0	0.0
Amortization of Prior Service Credit (Cost)		0.0	0.0
Change for the Year		$ (42.4)	$ (42.0)
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	[1]	4.85%	4.85%
Company Contributions		$ 0.0	$ 7.0
Pension Plans [Member] | Appalachian Power Co [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		82.5	124.7
Pension Plans [Member] | Appalachian Power Co [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		0.3	0.3
Pension Plans [Member] | Appalachian Power Co [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		$ 1.1	$ 1.3
Pension Plans [Member] | Indiana Michigan Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.90%	2.50%
Interest Crediting Rate		4.00%	4.00%
Rate of Compensation Increase	[1]	5.00%	5.00%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		2.50%	3.25%	4.30%
Interest Crediting Rate		4.00%	4.00%	4.00%
Expected Return on Plan Assets		4.75%	5.75%	6.25%
Rate of Compensation Increase	[2]	5.00%	5.00%	4.95%
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 653.3	$ 616.1
Service Cost		17.5	15.4	$ 13.4
Interest Cost		16.2	19.7	23.8
Actuarial (Gain) Loss		(29.5)	44.3
Plan Amendments		0.0	0.0
Benefit Payments		(45.4)	(42.2)
Participant Contributions		0.0	0.0
Benefit Obligation as of December 31		612.1	653.3	616.1
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		698.1	630.5
Actual Gain (Loss) on Plan Assets		28.8	103.3
Company Contributions		0.0	6.5
Participant Contributions		0.0	0.0
Benefit Payments		(45.4)	(42.2)
Fair Value of Plan Assets as of December 31		681.5	698.1	$ 630.5
Funded (Underfunded) Status as of December 31		69.4	44.8
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		71.4	46.5
Other Current Liabilities - Accrued Short-term Benefit Liability		(0.1)	0.0
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		(1.9)	(1.7)
Funded (Underfunded) Status		69.4	44.8
Components
Net Actuarial Loss		(1.6)	39.5
Prior Service Cost (Credit)		0.0	0.0
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(29.4)	(25.7)
Amortization of Actuarial Gain (Loss)		(11.7)	(10.8)
Prior Service (Credit) Cost		0.0	0.0
Amortization of Prior Service Credit (Cost)		0.0	0.0
Change for the Year		$ (41.1)	$ (36.5)
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	[1]	5.00%	5.00%
Company Contributions		$ 0.0	$ 6.5
Pension Plans [Member] | Indiana Michigan Power Co [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	[4]	3.1	40.3
Pension Plans [Member] | Indiana Michigan Power Co [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		(1.0)	(0.1)
Pension Plans [Member] | Indiana Michigan Power Co [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		$ (3.7)	$ (0.7)
Pension Plans [Member] | Ohio Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.90%	2.50%
Interest Crediting Rate		4.00%	4.00%
Rate of Compensation Increase	[1]	5.30%	5.25%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		2.50%	3.25%	4.30%
Interest Crediting Rate		4.00%	4.00%	4.00%
Expected Return on Plan Assets		4.75%	5.75%	6.25%
Rate of Compensation Increase	[2]	5.30%	5.25%	5.20%
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 510.3	$ 487.8
Service Cost		11.4	9.7	$ 7.9
Interest Cost		12.5	15.4	19.1
Actuarial (Gain) Loss		(24.1)	33.4
Plan Amendments		0.0	0.0
Benefit Payments		(39.4)	(36.0)
Participant Contributions		0.0	0.0
Benefit Obligation as of December 31		470.7	510.3	487.8
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		543.1	499.1
Actual Gain (Loss) on Plan Assets		21.1	79.9
Company Contributions		0.0	0.1
Participant Contributions		0.0	0.0
Benefit Payments		(39.4)	(36.0)
Fair Value of Plan Assets as of December 31		524.8	543.1	$ 499.1
Funded (Underfunded) Status as of December 31		54.1	32.8
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		54.8	33.3
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		(0.7)	(0.5)
Funded (Underfunded) Status		54.1	32.8
Components
Net Actuarial Loss		118.1	150.0
Prior Service Cost (Credit)		0.0	0.0
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(22.8)	(20.2)
Amortization of Actuarial Gain (Loss)		(9.1)	(8.5)
Prior Service (Credit) Cost		0.0	0.0
Amortization of Prior Service Credit (Cost)		0.0	0.0
Change for the Year		$ (31.9)	$ (28.7)
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	[1]	5.30%	5.25%
Company Contributions		$ 0.0	$ 0.1
Pension Plans [Member] | Ohio Power Co [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		$ 118.1	$ 150.0
Pension Plans [Member] | Public Service Co Of Oklahoma [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.90%	2.50%
Interest Crediting Rate		4.00%	4.00%
Rate of Compensation Increase	[1]	5.10%	5.05%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		2.50%	3.25%	4.30%
Interest Crediting Rate		4.00%	4.00%	4.00%
Expected Return on Plan Assets		4.75%	5.75%	6.25%
Rate of Compensation Increase	[2]	5.10%	5.05%	5.05%
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 279.9	$ 267.5
Service Cost		8.0	7.3	$ 6.5
Interest Cost		6.7	8.5	10.6
Actuarial (Gain) Loss		(17.2)	17.7
Plan Amendments		0.0	0.0
Benefit Payments		(24.8)	(21.1)
Participant Contributions		0.0	0.0
Benefit Obligation as of December 31		252.6	279.9	267.5
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		299.8	276.2
Actual Gain (Loss) on Plan Assets		11.1	44.6
Company Contributions		0.1	0.1
Participant Contributions		0.0	0.0
Benefit Payments		(24.8)	(21.1)
Fair Value of Plan Assets as of December 31		286.2	299.8	$ 276.2
Funded (Underfunded) Status as of December 31		33.6	19.9
Benefit Amounts Recognized on the Balance Sheets
Employee Benefits and Pension Assets - Prepaid Benefit Costs		35.5	21.9
Other Current Liabilities - Accrued Short-term Benefit Liability		(0.1)	(0.1)
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		(1.8)	(1.9)
Funded (Underfunded) Status		33.6	19.9
Components
Net Actuarial Loss		35.0	55.9
Prior Service Cost (Credit)		0.0	0.0
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(16.0)	(12.4)
Amortization of Actuarial Gain (Loss)		(4.9)	(4.7)
Prior Service (Credit) Cost		0.0	0.0
Amortization of Prior Service Credit (Cost)		0.0	0.0
Change for the Year		$ (20.9)	$ (17.1)
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	[1]	5.10%	5.05%
Company Contributions		$ 0.1	$ 0.1
Pension Plans [Member] | Public Service Co Of Oklahoma [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		$ 35.0	$ 55.9
Pension Plans [Member] | Southwestern Electric Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.90%	2.50%
Interest Crediting Rate		4.00%	4.00%
Rate of Compensation Increase	[1]	4.95%	4.90%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		2.50%	3.25%	4.30%
Interest Crediting Rate		4.00%	4.00%	4.00%
Expected Return on Plan Assets		4.75%	5.75%	6.25%
Rate of Compensation Increase	[2]	4.95%	4.90%	4.90%
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 334.5	$ 314.2
Service Cost		11.2	9.9	$ 8.6
Interest Cost		8.5	10.2	12.4
Actuarial (Gain) Loss		(3.5)	27.4
Plan Amendments		0.0	0.0
Benefit Payments		(33.0)	(27.2)
Participant Contributions		0.0	0.0
Benefit Obligation as of December 31		317.7	334.5	314.2
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		326.9	296.9
Actual Gain (Loss) on Plan Assets		14.3	48.2
Company Contributions		0.1	9.0
Participant Contributions		0.0	0.0
Benefit Payments		(33.0)	(27.2)
Fair Value of Plan Assets as of December 31		308.3	326.9	$ 296.9
Funded (Underfunded) Status as of December 31		(9.4)	(7.6)
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		0.0	0.0
Other Current Liabilities - Accrued Short-term Benefit Liability		(0.1)	(0.1)
Employee Benefits and Pension Obligations - Accrued Long-term Benefit Liability		(9.3)	(7.5)
Funded (Underfunded) Status		(9.4)	(7.6)
Components
Net Actuarial Loss		76.4	86.9
Prior Service Cost (Credit)		0.0	0.0
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(4.3)	(5.2)
Amortization of Actuarial Gain (Loss)		(6.2)	(5.7)
Prior Service (Credit) Cost		0.0	0.0
Amortization of Prior Service Credit (Cost)		0.0	0.0
Change for the Year		$ (10.5)	$ (10.9)
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase	[1]	4.95%	4.90%
Company Contributions		$ 0.1	$ 9.0
Pension Plans [Member] | Southwestern Electric Power Co [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		76.4	86.9
Pension Plans [Member] | Southwestern Electric Power Co [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		0.0	0.0
Pension Plans [Member] | Southwestern Electric Power Co [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		$ 0.0	0.0
Pension Plans [Member] | Minimum [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase		3.00%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase		3.00%
Pension Plans [Member] | Minimum [Member] | AEP Texas Inc. [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase		3.00%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase		3.00%
Pension Plans [Member] | Minimum [Member] | Appalachian Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase		3.00%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase		3.00%
Pension Plans [Member] | Minimum [Member] | Indiana Michigan Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase		3.00%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase		3.00%
Pension Plans [Member] | Minimum [Member] | Ohio Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase		3.00%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase		3.00%
Pension Plans [Member] | Minimum [Member] | Public Service Co Of Oklahoma [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase		3.00%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase		3.00%
Pension Plans [Member] | Minimum [Member] | Southwestern Electric Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase		3.00%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase		3.00%
Pension Plans [Member] | Maximum [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase		11.50%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase		11.50%
Pension Plans [Member] | Maximum [Member] | AEP Texas Inc. [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase		11.50%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase		11.50%
Pension Plans [Member] | Maximum [Member] | Appalachian Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase		11.50%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase		11.50%
Pension Plans [Member] | Maximum [Member] | Indiana Michigan Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase		11.50%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase		11.50%
Pension Plans [Member] | Maximum [Member] | Ohio Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase		11.50%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase		11.50%
Pension Plans [Member] | Maximum [Member] | Public Service Co Of Oklahoma [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase		11.50%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase		11.50%
Pension Plans [Member] | Maximum [Member] | Southwestern Electric Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Rate of Compensation Increase		11.50%
Benefit Plans (Textuals) [Abstract]
Rate of Compensation Increase		11.50%
Qualified Pension Plans [Member]
Change in Fair Value of Plan Assets
Company Contributions		$ 0.0	110.0
Benefit Plans (Textuals) [Abstract]
Company Contributions		0.0	110.0
Nonqualified Pension Plans [Member]
Change in Benefit Obligation
Benefit Obligation as of January 1		81.4
Benefit Obligation as of December 31		78.4	81.4
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		0.0
Company Contributions		7.0	6.0
Fair Value of Plan Assets as of December 31		0.0	0.0
Benefit Plans (Textuals) [Abstract]
Company Contributions		7.0	6.0
Nonqualified Pension Plans [Member] | AEP Texas Inc. [Member]
Change in Benefit Obligation
Benefit Obligation as of January 1		3.9
Benefit Obligation as of December 31		3.6	3.9
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		0.0
Fair Value of Plan Assets as of December 31		0.0	0.0
Nonqualified Pension Plans [Member] | Appalachian Power Co [Member]
Change in Benefit Obligation
Benefit Obligation as of January 1		0.5
Benefit Obligation as of December 31		0.8	0.5
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		0.0
Fair Value of Plan Assets as of December 31		0.0	0.0
Nonqualified Pension Plans [Member] | Indiana Michigan Power Co [Member]
Change in Benefit Obligation
Benefit Obligation as of January 1		1.7
Benefit Obligation as of December 31		1.9	1.7
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		0.0
Fair Value of Plan Assets as of December 31		0.0	0.0
Nonqualified Pension Plans [Member] | Ohio Power Co [Member]
Change in Benefit Obligation
Benefit Obligation as of January 1		0.6
Benefit Obligation as of December 31		0.7	0.6
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		0.0
Fair Value of Plan Assets as of December 31		0.0	0.0
Nonqualified Pension Plans [Member] | Public Service Co Of Oklahoma [Member]
Change in Benefit Obligation
Benefit Obligation as of January 1		2.0
Benefit Obligation as of December 31		1.9	2.0
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		0.0
Fair Value of Plan Assets as of December 31		0.0	0.0
Nonqualified Pension Plans [Member] | Southwestern Electric Power Co [Member]
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		0.0
Fair Value of Plan Assets as of December 31		$ 0.0	$ 0.0
Other Postretirement Benefit Plans [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.90%	2.55%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		2.55%	3.30%	4.30%
Expected Return on Plan Assets		4.75%	5.50%	6.25%
Health Care Trend Rates
Initial		6.25%	6.50%
Ultimate		4.50%	4.50%
Year Ultimate Reached		2029	2029
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 1,210.9	$ 1,225.4
Service Cost		9.5	10.0	$ 9.5
Interest Cost		30.5	39.8	50.5
Actuarial (Gain) Loss		(120.1)	39.3
Plan Amendments		(5.4)	(11.4)
Benefit Payments		(126.0)	(131.0)
Participant Contributions		41.3	38.2
Medicare Subsidy		0.6	0.6
Benefit Obligation as of December 31		1,041.3	1,210.9	1,225.4
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		1,946.7	1,781.8
Actual Gain (Loss) on Plan Assets		176.5	253.0
Company Contributions	[3]	5.8	4.7
Participant Contributions		41.3	38.2
Benefit Payments		(126.0)	(131.0)
Fair Value of Plan Assets as of December 31		2,044.3	1,946.7	$ 1,781.8
Funded (Underfunded) Status as of December 31		1,003.0	735.8
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		1,040.8	771.9
Other Current Liabilities - Accrued Short-term Benefit Liability		(2.7)	(2.4)
Employee Benefits and Pension Obligations - Accrued Long-term Benefit Liability		(35.1)	(33.7)
Funded (Underfunded) Status		1,003.0	735.8
Components
Net Actuarial Loss		(103.6)	101.9
Prior Service Cost (Credit)		(161.9)	(227.3)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(205.5)	(118.0)
Amortization of Actuarial Gain (Loss)		0.0	(5.9)
Prior Service (Credit) Cost		(5.5)	(11.4)
Amortization of Prior Service Credit (Cost)		70.9	69.8
Change for the Year		(140.1)	(65.5)
Benefit Plans (Textuals) [Abstract]
Company Contributions	[3]	5.8	4.7
Other Postretirement Benefit Plans [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		(195.1)	(99.0)
Other Postretirement Benefit Plans [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		(14.7)	(5.5)
Other Postretirement Benefit Plans [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		$ (55.7)	$ (20.9)
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.90%	2.55%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		2.55%	3.30%	4.30%
Expected Return on Plan Assets		4.75%	5.50%	6.25%
Health Care Trend Rates
Initial		6.25%	6.50%
Ultimate		4.50%	4.50%
Year Ultimate Reached		2029	2029
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 96.3	$ 97.8
Service Cost		0.7	0.8	$ 0.8
Interest Cost		2.4	3.2	4.0
Actuarial (Gain) Loss		(12.3)	2.4
Plan Amendments		(0.5)	(1.0)
Benefit Payments		(9.3)	(10.0)
Participant Contributions		3.2	3.1
Benefit Obligation as of December 31		80.5	96.3	97.8
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		162.3	148.1
Actual Gain (Loss) on Plan Assets		12.5	21.1
Company Contributions		0.1	0.0
Participant Contributions		3.2	3.1
Benefit Payments		(9.3)	(10.0)
Fair Value of Plan Assets as of December 31		168.8	162.3	$ 148.1
Funded (Underfunded) Status as of December 31		88.3	66.0
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		88.3	66.0
Other Current Liabilities - Accrued Short-term Benefit Liability		0.0	0.0
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		0.0	0.0
Funded (Underfunded) Status		88.3	66.0
Components
Net Actuarial Loss		(5.2)	12.3
Prior Service Cost (Credit)		(13.7)	(19.3)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(17.5)	(10.7)
Amortization of Actuarial Gain (Loss)		0.0	(0.5)
Prior Service (Credit) Cost		(0.4)	(1.0)
Amortization of Prior Service Credit (Cost)		6.0	5.9
Change for the Year		(11.9)	(6.3)
Benefit Plans (Textuals) [Abstract]
Company Contributions		0.1	0.0
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		(17.7)	(6.3)
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		(0.2)	(0.1)
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		$ (1.0)	$ (0.6)
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.90%	2.55%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		2.55%	3.30%	4.30%
Expected Return on Plan Assets		4.75%	5.50%	6.25%
Health Care Trend Rates
Initial		6.25%	6.50%
Ultimate		4.50%	4.50%
Year Ultimate Reached		2029	2029
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 198.2	$ 203.5
Service Cost		1.0	1.0	$ 1.0
Interest Cost		4.9	6.6	8.7
Actuarial (Gain) Loss		(21.4)	5.6
Plan Amendments		(0.9)	(1.8)
Benefit Payments		(21.3)	(23.2)
Participant Contributions		6.6	6.3
Medicare Subsidy		0.2	0.2
Benefit Obligation as of December 31		167.3	198.2	203.5
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		293.0	271.0
Actual Gain (Loss) on Plan Assets		21.9	36.8
Company Contributions		2.1	2.1
Participant Contributions		6.6	6.3
Benefit Payments		(21.3)	(23.2)
Fair Value of Plan Assets as of December 31		302.3	293.0	$ 271.0
Funded (Underfunded) Status as of December 31		135.0	94.8
Benefit Amounts Recognized on the Balance Sheets
Employee Benefits and Pension Assets - Prepaid Benefit Costs		158.1	119.1
Other Current Liabilities - Accrued Short-term Benefit Liability		(1.8)	(1.8)
Employee Benefits and Pension Obligations - Accrued Long-term Benefit Liability		(21.3)	(22.5)
Funded (Underfunded) Status		135.0	94.8
Components
Net Actuarial Loss		(18.9)	11.1
Prior Service Cost (Credit)		(23.8)	(33.2)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(30.0)	(16.8)
Amortization of Actuarial Gain (Loss)		0.0	(0.9)
Prior Service (Credit) Cost		(0.9)	(1.8)
Amortization of Prior Service Credit (Cost)		10.3	10.2
Change for the Year		(20.6)	(9.3)
Benefit Plans (Textuals) [Abstract]
Company Contributions		2.1	2.1
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		(19.8)	(10.3)
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		(4.9)	(2.5)
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		$ (18.0)	$ (9.3)
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.90%	2.55%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		2.55%	3.30%	4.30%
Expected Return on Plan Assets		4.75%	5.50%	6.25%
Health Care Trend Rates
Initial		6.25%	6.50%
Ultimate		4.50%	4.50%
Year Ultimate Reached		2029	2029
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 141.4	$ 142.9
Service Cost		1.3	1.4	$ 1.4
Interest Cost		3.5	4.7	5.8
Actuarial (Gain) Loss		(16.8)	5.1
Plan Amendments		(0.7)	(1.6)
Benefit Payments		(15.3)	(15.9)
Participant Contributions		5.2	4.8
Benefit Obligation as of December 31		118.6	141.4	142.9
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		238.2	216.3
Actual Gain (Loss) on Plan Assets		20.6	33.0
Company Contributions		0.0	0.0
Participant Contributions		5.2	4.8
Benefit Payments		(15.3)	(15.9)
Fair Value of Plan Assets as of December 31		248.7	238.2	$ 216.3
Funded (Underfunded) Status as of December 31		130.1	96.8
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		130.1	96.8
Other Current Liabilities - Accrued Short-term Benefit Liability		0.0	0.0
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		0.0	0.0
Funded (Underfunded) Status		130.1	96.8
Components
Net Actuarial Loss		(10.7)	15.6
Prior Service Cost (Credit)		(22.1)	(31.0)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(26.3)	(16.4)
Amortization of Actuarial Gain (Loss)		0.0	(0.7)
Prior Service (Credit) Cost		(0.7)	(1.5)
Amortization of Prior Service Credit (Cost)		9.6	9.5
Change for the Year		(17.4)	(9.1)
Benefit Plans (Textuals) [Abstract]
Company Contributions		0.0	0.0
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets	[4]	(30.7)	(14.6)
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		(0.4)	(0.2)
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		$ (1.7)	$ (0.6)
Other Postretirement Benefit Plans [Member] | Ohio Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.90%	2.55%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		2.55%	3.30%	4.30%
Expected Return on Plan Assets		4.75%	5.50%	6.25%
Health Care Trend Rates
Initial		6.25%	6.50%
Ultimate		4.50%	4.50%
Year Ultimate Reached		2029	2029
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 126.4	$ 130.2
Service Cost		0.8	0.9	$ 0.8
Interest Cost		3.0	4.2	5.5
Actuarial (Gain) Loss		(15.6)	3.1
Plan Amendments		(0.6)	(1.3)
Benefit Payments		(13.6)	(15.0)
Participant Contributions		4.5	4.3
Benefit Obligation as of December 31		104.9	126.4	130.2
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		213.0	197.1
Actual Gain (Loss) on Plan Assets		16.1	26.6
Company Contributions		0.0	0.0
Participant Contributions		4.5	4.3
Benefit Payments		(13.6)	(15.0)
Fair Value of Plan Assets as of December 31		220.0	213.0	$ 197.1
Funded (Underfunded) Status as of December 31		115.1	86.6
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		115.1	86.6
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		0.0	0.0
Funded (Underfunded) Status		115.1	86.6
Components
Net Actuarial Loss		(18.5)	3.6
Prior Service Cost (Credit)		(16.3)	(22.9)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(22.1)	(12.9)
Amortization of Actuarial Gain (Loss)		0.0	(0.7)
Prior Service (Credit) Cost		(0.6)	(1.3)
Amortization of Prior Service Credit (Cost)		7.2	7.0
Change for the Year		(15.5)	(7.9)
Benefit Plans (Textuals) [Abstract]
Company Contributions		0.0	0.0
Other Postretirement Benefit Plans [Member] | Ohio Power Co [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		$ (34.8)	$ (19.3)
Other Postretirement Benefit Plans [Member] | Public Service Co Of Oklahoma [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.90%	2.55%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		2.55%	3.30%	4.30%
Expected Return on Plan Assets		4.75%	5.50%	6.25%
Health Care Trend Rates
Initial		6.25%	6.50%
Ultimate		4.50%	4.50%
Year Ultimate Reached		2029	2029
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 64.0	$ 64.7
Service Cost		0.6	0.7	$ 0.6
Interest Cost		1.6	2.1	2.6
Actuarial (Gain) Loss		(6.8)	1.9
Plan Amendments		(0.3)	(0.7)
Benefit Payments		(7.0)	(6.8)
Participant Contributions		2.3	2.1
Benefit Obligation as of December 31		54.4	64.0	64.7
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		107.8	98.0
Actual Gain (Loss) on Plan Assets		10.9	14.5
Company Contributions		0.0	0.0
Participant Contributions		2.3	2.1
Benefit Payments		(7.0)	(6.8)
Fair Value of Plan Assets as of December 31		114.0	107.8	$ 98.0
Funded (Underfunded) Status as of December 31		59.6	43.8
Benefit Amounts Recognized on the Balance Sheets
Employee Benefits and Pension Assets - Prepaid Benefit Costs		59.6	43.8
Other Current Liabilities - Accrued Short-term Benefit Liability		0.0	0.0
Deferred Credits and Other Noncurrent Liabilities - Accrued Long-term Benefit Liability		0.0	0.0
Funded (Underfunded) Status		59.6	43.8
Components
Net Actuarial Loss		(2.1)	10.5
Prior Service Cost (Credit)		(10.0)	(14.1)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(12.6)	(7.4)
Amortization of Actuarial Gain (Loss)		0.0	(0.3)
Prior Service (Credit) Cost		(0.3)	(0.7)
Amortization of Prior Service Credit (Cost)		4.4	4.4
Change for the Year		(8.5)	(4.0)
Benefit Plans (Textuals) [Abstract]
Company Contributions		0.0	0.0
Other Postretirement Benefit Plans [Member] | Public Service Co Of Oklahoma [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		$ (12.1)	$ (3.6)
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member]
Actuarial Assumptions for Benefit Obligations
Discount Rate		2.90%	2.55%
Actuarial Assumptions for Net Periodic Benefit Costs
Discount Rate		2.55%	3.30%	4.30%
Expected Return on Plan Assets		4.75%	5.50%	6.25%
Health Care Trend Rates
Initial		6.25%	6.50%
Ultimate		4.50%	4.50%
Year Ultimate Reached		2029	2029
Change in Benefit Obligation
Benefit Obligation as of January 1		$ 77.1	$ 77.4
Service Cost		0.8	0.8	$ 0.8
Interest Cost		1.9	2.5	3.1
Actuarial (Gain) Loss		(9.2)	2.5
Plan Amendments		(0.4)	(0.8)
Benefit Payments		(7.6)	(7.7)
Participant Contributions		2.6	2.4
Benefit Obligation as of December 31		65.2	77.1	77.4
Change in Fair Value of Plan Assets
Fair Value of Plan Assets as of January 1		129.9	117.2
Actual Gain (Loss) on Plan Assets		11.7	18.0
Company Contributions		0.0	0.0
Participant Contributions		2.6	2.4
Benefit Payments		(7.6)	(7.7)
Fair Value of Plan Assets as of December 31		136.6	129.9	$ 117.2
Funded (Underfunded) Status as of December 31		71.4	52.8
Benefit Amounts Recognized on the Balance Sheets
Deferred Charges and Other Noncurrent Assets - Prepaid Benefit Costs		71.4	52.8
Other Current Liabilities - Accrued Short-term Benefit Liability		0.0	0.0
Employee Benefits and Pension Obligations - Accrued Long-term Benefit Liability		0.0	0.0
Funded (Underfunded) Status		71.4	52.8
Components
Net Actuarial Loss		(3.5)	11.5
Prior Service Cost (Credit)		(12.3)	(17.2)
Components of Change in Amounts Included in AOCI and Regulatory Assets
Actuarial (Gain) Loss During the Year		(15.0)	(9.2)
Amortization of Actuarial Gain (Loss)		0.0	(0.4)
Prior Service (Credit) Cost		(0.4)	(0.8)
Amortization of Prior Service Credit (Cost)		5.3	5.2
Change for the Year		(10.1)	(5.2)
Benefit Plans (Textuals) [Abstract]
Company Contributions		0.0	0.0
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member] | Regulatory Assets [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		(8.9)	(3.0)
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member] | Deferred Income Taxes [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		(1.4)	(0.5)
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member] | Net of Tax AOCI [Member]
Recorded as
Total of Amounts Included in AOCI, Income Tax Expense and Regulatory Assets		$ (5.5)	$ (2.2)

[1] Rates are for base pay only.  In addition, an amount is added to reflect target incentive compensation for exempt employees and overtime and incentive pay for nonexempt employees.

[2] Rates are for base pay only.  In addition, an amount is added to reflect target incentive compensation for exempt employees and overtime and incentive pay for nonexempt employees.

[3] Contributions to the qualified pension plan were $0 and $110 million for the years ended December 31, 2021 and 2020, respectively. Contributions to the non-qualified pension plans were $7 million and $6 million for the years ended December 31, 2021 and 2020, respectively.

[4] Recorded as a Regulatory Liability as of December 31, 2021 and recorded as a Regulatory Asset as of December 31, 2020.