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Benefit Plans 3 (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
American Electric Power System Retirement Savings Plans |  |  |
Cost of Company Matching Contributions | $ 87,900 | $ 81,900 | $ 79,900
Benefit Plans Textuals [Abstract] |  |  |
Matching Contributions Provided Percentage | 100.00% |  |
Eligible Compensation Contribution by Employee Percentage | 1.00% |  |
Second Matching Contributions Provided Percentage | 70.00% |  |
Second Eligible Compensation Contribution by Employee Percentage | 5.00% |  |
Multiemployer Plans Withdrawal Obligation | $ 13,000 | 12,000 |
Noncurrent Regulatory Assets | 5,092,400 | 4,762,000 |
Noncurrent Regulatory Liabilities | 8,182,400 | 8,115,600 |
Multiemployer Plan, Employer Contribution, Cost | 396 | 329 | 339
AEP Texas Inc. [Member] |  |  |
American Electric Power System Retirement Savings Plans |  |  |
Cost of Company Matching Contributions | $ 7,100 | 6,500 | 6,400
Benefit Plans Textuals [Abstract] |  |  |
Matching Contributions Provided Percentage | 100.00% |  |
Eligible Compensation Contribution by Employee Percentage | 1.00% |  |
Second Matching Contributions Provided Percentage | 70.00% |  |
Second Eligible Compensation Contribution by Employee Percentage | 5.00% |  |
Noncurrent Regulatory Assets | $ 315,300 | 298,300 |
Noncurrent Regulatory Liabilities | 1,261,400 | 1,259,600 |
Appalachian Power Co [Member] |  |  |
American Electric Power System Retirement Savings Plans |  |  |
Cost of Company Matching Contributions | $ 8,400 | 7,800 | 7,600
Benefit Plans Textuals [Abstract] |  |  |
Matching Contributions Provided Percentage | 100.00% |  |
Eligible Compensation Contribution by Employee Percentage | 1.00% |  |
Second Matching Contributions Provided Percentage | 70.00% |  |
Second Eligible Compensation Contribution by Employee Percentage | 5.00% |  |
Noncurrent Regulatory Assets | $ 1,155,100 | 1,058,600 |
Noncurrent Regulatory Liabilities | 1,081,900 | 1,143,600 |
Indiana Michigan Power Co [Member] |  |  |
American Electric Power System Retirement Savings Plans |  |  |
Cost of Company Matching Contributions | $ 11,000 | 11,100 | 10,900
Benefit Plans Textuals [Abstract] |  |  |
Matching Contributions Provided Percentage | 100.00% |  |
Eligible Compensation Contribution by Employee Percentage | 1.00% |  |
Second Matching Contributions Provided Percentage | 70.00% |  |
Second Eligible Compensation Contribution by Employee Percentage | 5.00% |  |
Noncurrent Regulatory Assets | $ 406,300 | 459,600 |
Noncurrent Regulatory Liabilities | 2,052,300 | 1,702,200 |
Ohio Power Co [Member] |  |  |
American Electric Power System Retirement Savings Plans |  |  |
Cost of Company Matching Contributions | $ 8,200 | 7,700 | 7,200
Benefit Plans Textuals [Abstract] |  |  |
Matching Contributions Provided Percentage | 100.00% |  |
Eligible Compensation Contribution by Employee Percentage | 1.00% |  |
Second Matching Contributions Provided Percentage | 70.00% |  |
Second Eligible Compensation Contribution by Employee Percentage | 5.00% |  |
Noncurrent Regulatory Assets | $ 455,000 | 327,300 |
Noncurrent Regulatory Liabilities | 1,003,600 | 1,044,000 |
Public Service Co Of Oklahoma [Member] |  |  |
American Electric Power System Retirement Savings Plans |  |  |
Cost of Company Matching Contributions | $ 5,300 | 4,700 | 4,600
Benefit Plans Textuals [Abstract] |  |  |
Matching Contributions Provided Percentage | 100.00% |  |
Eligible Compensation Contribution by Employee Percentage | 1.00% |  |
Second Matching Contributions Provided Percentage | 70.00% |  |
Second Eligible Compensation Contribution by Employee Percentage | 5.00% |  |
Noncurrent Regulatory Assets | $ 522,700 | 653,700 |
Noncurrent Regulatory Liabilities | 765,600 | 809,100 |
Southwestern Electric Power Co [Member] |  |  |
American Electric Power System Retirement Savings Plans |  |  |
Cost of Company Matching Contributions | $ 6,700 | 6,400 | 6,400
Benefit Plans Textuals [Abstract] |  |  |
Matching Contributions Provided Percentage | 100.00% |  |
Eligible Compensation Contribution by Employee Percentage | 1.00% |  |
Second Matching Contributions Provided Percentage | 70.00% |  |
Second Eligible Compensation Contribution by Employee Percentage | 5.00% |  |
Noncurrent Regulatory Assets | $ 1,131,800 | 1,042,400 |
Noncurrent Regulatory Liabilities | 756,100 | 825,700 |
Pension Plans [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 3,933,500 | 3,883,000 |
Underfunded Benefit Obligation |  |  |
Projected Benefit Obligation | 4,161,600 | 4,072,700 | 5,187,000
Accumulated Benefit Obligation | 3,933,500 | 3,883,000 |
Fair Value of Plan Assets | 4,118,200 | 4,124,700 | 5,352,900
Estimated Future Benefit Payments and Contributions |  |  |
Expected Contributions and Payments During 2024 | 6,700 |  |
Components of Net Periodic Benefit Cost |  |  |
Service Cost | 94,300 | 123,100 | 129,200
Interest Cost | 219,200 | 148,200 | 137,200
Expected Return on Plan Assets | (339,200) | (253,400) | (229,700)
Amortization of Net Actuarial Loss | 1,400 | 63,000 | 101,500
Net Periodic Benefit Cost (Credit) | (24,300) | 80,900 | 138,200
Capitalized Portion | (43,600) | (53,800) | (55,700)
Net Periodic Benefit Cost (Credit) Recognized in Expense | (67,900) | 27,100 | 82,500
Pension Plans [Member] | Pension Payments [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 369,500 |  |
Year Two | 361,800 |  |
Year Three | 365,700 |  |
Year Four | 361,900 |  |
Year Five | 357,800 |  |
After Year Five for Next Five Years, in Total | 1,657,600 |  |
Pension Plans [Member] | AEP Texas Inc. [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 323,200 | 317,900 |
Underfunded Benefit Obligation |  |  |
Projected Benefit Obligation | 343,100 | 334,100 | 419,800
Accumulated Benefit Obligation | 323,200 | 317,900 |
Fair Value of Plan Assets | 332,700 | 335,100 | 444,900
Estimated Future Benefit Payments and Contributions |  |  |
Expected Contributions and Payments During 2024 | 300 |  |
Components of Net Periodic Benefit Cost |  |  |
Service Cost | 8,200 | 11,100 | 11,800
Interest Cost | 18,300 | 12,100 | 11,200
Expected Return on Plan Assets | (28,100) | (21,000) | (19,500)
Amortization of Net Actuarial Loss | 100 | 5,200 | 8,300
Net Periodic Benefit Cost (Credit) | (1,500) | 7,400 | 11,800
Capitalized Portion | (4,700) | (6,200) | (6,600)
Net Periodic Benefit Cost (Credit) Recognized in Expense | (6,200) | 1,200 | 5,200
Pension Plans [Member] | AEP Texas Inc. [Member] | Pension Payments [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 36,700 |  |
Year Two | 34,300 |  |
Year Three | 34,500 |  |
Year Four | 32,200 |  |
Year Five | 32,200 |  |
After Year Five for Next Five Years, in Total | 133,500 |  |
Pension Plans [Member] | Appalachian Power Co [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 485,700 | 470,400 |
Underfunded Benefit Obligation |  |  |
Projected Benefit Obligation | 504,100 | 485,700 | 621,700
Accumulated Benefit Obligation | 485,700 | 470,400 |
Fair Value of Plan Assets | 549,800 | 531,700 | 683,300
Estimated Future Benefit Payments and Contributions |  |  |
Expected Contributions and Payments During 2024 | 0 |  |
Components of Net Periodic Benefit Cost |  |  |
Service Cost | 9,100 | 11,400 | 11,900
Interest Cost | 26,400 | 17,500 | 16,400
Expected Return on Plan Assets | (44,600) | (32,300) | (29,100)
Amortization of Net Actuarial Loss | 0 | 7,400 | 12,000
Net Periodic Benefit Cost (Credit) | (9,100) | 4,000 | 11,200
Capitalized Portion | (4,200) | (5,000) | (5,200)
Net Periodic Benefit Cost (Credit) Recognized in Expense | (13,300) | (1,000) | 6,000
Pension Plans [Member] | Appalachian Power Co [Member] | Pension Payments [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 43,900 |  |
Year Two | 43,300 |  |
Year Three | 44,100 |  |
Year Four | 42,600 |  |
Year Five | 43,500 |  |
After Year Five for Next Five Years, in Total | 200,000 |  |
Pension Plans [Member] | Indiana Michigan Power Co [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 451,000 | 445,000 |
Underfunded Benefit Obligation |  |  |
Projected Benefit Obligation | 477,000 | 466,800 | 612,100
Accumulated Benefit Obligation | 451,000 | 445,000 |
Fair Value of Plan Assets | 550,600 | 533,700 | 681,500
Estimated Future Benefit Payments and Contributions |  |  |
Expected Contributions and Payments During 2024 | 0 |  |
Components of Net Periodic Benefit Cost |  |  |
Service Cost | 11,900 | 16,200 | 17,500
Interest Cost | 24,900 | 17,000 | 16,200
Expected Return on Plan Assets | (44,200) | (32,400) | (28,900)
Amortization of Net Actuarial Loss | 100 | 7,100 | 11,700
Net Periodic Benefit Cost (Credit) | (7,300) | 7,900 | 16,500
Capitalized Portion | (3,600) | (4,600) | (4,900)
Net Periodic Benefit Cost (Credit) Recognized in Expense | (10,900) | 3,300 | 11,600
Pension Plans [Member] | Indiana Michigan Power Co [Member] | Pension Payments [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 39,000 |  |
Year Two | 39,700 |  |
Year Three | 39,700 |  |
Year Four | 39,800 |  |
Year Five | 39,400 |  |
After Year Five for Next Five Years, in Total | 189,400 |  |
Pension Plans [Member] | Ohio Power Co [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 354,100 | 344,200 |
Underfunded Benefit Obligation |  |  |
Projected Benefit Obligation | 378,400 | 363,600 | 470,700
Accumulated Benefit Obligation | 354,100 | 344,200 |
Fair Value of Plan Assets | 419,500 | 406,400 | 524,800
Estimated Future Benefit Payments and Contributions |  |  |
Expected Contributions and Payments During 2024 | 0 |  |
Components of Net Periodic Benefit Cost |  |  |
Service Cost | 8,400 | 11,200 | 11,400
Interest Cost | 19,800 | 13,300 | 12,500
Expected Return on Plan Assets | (34,000) | (24,800) | (22,300)
Amortization of Net Actuarial Loss | 0 | 5,500 | 9,100
Net Periodic Benefit Cost (Credit) | (5,800) | 5,200 | 10,700
Capitalized Portion | (4,700) | (6,100) | (6,200)
Net Periodic Benefit Cost (Credit) Recognized in Expense | (10,500) | (900) | 4,500
Pension Plans [Member] | Ohio Power Co [Member] | Pension Payments [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 32,600 |  |
Year Two | 32,700 |  |
Year Three | 32,500 |  |
Year Four | 32,400 |  |
Year Five | 31,300 |  |
After Year Five for Next Five Years, in Total | 144,500 |  |
Pension Plans [Member] | Public Service Co Of Oklahoma [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 187,800 | 180,300 |
Underfunded Benefit Obligation |  |  |
Projected Benefit Obligation | 202,200 | 192,300 | 252,600
Accumulated Benefit Obligation | 187,800 | 180,300 |
Fair Value of Plan Assets | 222,700 | 218,500 | 286,200
Estimated Future Benefit Payments and Contributions |  |  |
Expected Contributions and Payments During 2024 | 100 |  |
Components of Net Periodic Benefit Cost |  |  |
Service Cost | 5,500 | 7,400 | 8,000
Interest Cost | 10,700 | 7,000 | 6,700
Expected Return on Plan Assets | (18,300) | (13,400) | (12,300)
Amortization of Net Actuarial Loss | 0 | 2,900 | 4,900
Net Periodic Benefit Cost (Credit) | (2,100) | 3,900 | 7,300
Capitalized Portion | (2,500) | (3,200) | (3,400)
Net Periodic Benefit Cost (Credit) Recognized in Expense | (4,600) | 700 | 3,900
Pension Plans [Member] | Public Service Co Of Oklahoma [Member] | Pension Payments [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 19,700 |  |
Year Two | 19,200 |  |
Year Three | 19,400 |  |
Year Four | 19,300 |  |
Year Five | 19,000 |  |
After Year Five for Next Five Years, in Total | 81,000 |  |
Pension Plans [Member] | Southwestern Electric Power Co [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 242,900 | 235,100 |
Underfunded Benefit Obligation |  |  |
Projected Benefit Obligation | 261,200 | 250,700 | 317,700
Accumulated Benefit Obligation | 242,900 | 235,100 |
Fair Value of Plan Assets | 227,500 | 231,300 | 308,300
Underfunded Status, Projected Benefit Obligation | (33,700) | (19,400) |
Estimated Future Benefit Payments and Contributions |  |  |
Expected Contributions and Payments During 2024 | 100 |  |
Components of Net Periodic Benefit Cost |  |  |
Service Cost | 7,700 | 10,600 | 11,200
Interest Cost | 13,900 | 9,100 | 8,500
Expected Return on Plan Assets | (19,400) | (14,600) | (13,500)
Amortization of Net Actuarial Loss | 100 | 3,800 | 6,200
Net Periodic Benefit Cost (Credit) | 2,300 | 8,900 | 12,400
Capitalized Portion | (3,000) | (4,000) | (4,100)
Net Periodic Benefit Cost (Credit) Recognized in Expense | (700) | 4,900 | 8,300
Pension Plans [Member] | Southwestern Electric Power Co [Member] | Pension Payments [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 24,400 |  |
Year Two | 25,800 |  |
Year Three | 26,100 |  |
Year Four | 25,300 |  |
Year Five | 23,700 |  |
After Year Five for Next Five Years, in Total | 105,600 |  |
Qualified Pension Plans [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 3,878,700 | 3,827,400 |
Underfunded Benefit Obligation |  |  |
Accumulated Benefit Obligation | 3,878,700 | 3,827,400 |
Qualified Pension Plans [Member] | AEP Texas Inc. [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 321,100 | 315,400 |
Underfunded Benefit Obligation |  |  |
Accumulated Benefit Obligation | 321,100 | 315,400 |
Qualified Pension Plans [Member] | Appalachian Power Co [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 485,600 | 470,100 |
Underfunded Benefit Obligation |  |  |
Accumulated Benefit Obligation | 485,600 | 470,100 |
Qualified Pension Plans [Member] | Indiana Michigan Power Co [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 450,300 | 443,800 |
Underfunded Benefit Obligation |  |  |
Accumulated Benefit Obligation | 450,300 | 443,800 |
Qualified Pension Plans [Member] | Ohio Power Co [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 354,000 | 344,100 |
Underfunded Benefit Obligation |  |  |
Accumulated Benefit Obligation | 354,000 | 344,100 |
Qualified Pension Plans [Member] | Public Service Co Of Oklahoma [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 186,600 | 179,100 |
Underfunded Benefit Obligation |  |  |
Accumulated Benefit Obligation | 186,600 | 179,100 |
Qualified Pension Plans [Member] | Southwestern Electric Power Co [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 241,900 | 234,000 |
Underfunded Benefit Obligation |  |  |
Accumulated Benefit Obligation | 241,900 | 234,000 |
Nonqualified Pension Plans [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 54,800 | 55,600 |
Underfunded Benefit Obligation |  |  |
Projected Benefit Obligation | 60,700 | 61,500 |
Accumulated Benefit Obligation | 54,800 | 55,600 |
Fair Value of Plan Assets | 0 | 0 |
Underfunded Status, Projected Benefit Obligation | (60,700) | (61,500) |
Underfunded Status, Accumulated Benefit Obligation | (54,800) | (55,600) |
Nonqualified Pension Plans [Member] | AEP Texas Inc. [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 2,100 | 2,500 |
Underfunded Benefit Obligation |  |  |
Projected Benefit Obligation |  | 2,700 |
Accumulated Benefit Obligation | 2,100 | 2,500 |
Fair Value of Plan Assets | 0 | 0 |
Underfunded Status, Projected Benefit Obligation | (10,400) | (2,700) |
Underfunded Status, Accumulated Benefit Obligation | (2,100) | (2,500) |
Nonqualified Pension Plans [Member] | Appalachian Power Co [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 100 | 300 |
Underfunded Benefit Obligation |  |  |
Projected Benefit Obligation | 400 | 600 |
Accumulated Benefit Obligation | 100 | 300 |
Fair Value of Plan Assets | 0 | 0 |
Underfunded Status, Projected Benefit Obligation | (400) | (600) |
Underfunded Status, Accumulated Benefit Obligation | (100) | (300) |
Nonqualified Pension Plans [Member] | Indiana Michigan Power Co [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 700 | 1,200 |
Underfunded Benefit Obligation |  |  |
Projected Benefit Obligation | 1,200 | 1,600 |
Accumulated Benefit Obligation | 700 | 1,200 |
Fair Value of Plan Assets | 0 | 0 |
Underfunded Status, Projected Benefit Obligation | (1,200) | (1,600) |
Underfunded Status, Accumulated Benefit Obligation | (700) | (1,200) |
Nonqualified Pension Plans [Member] | Ohio Power Co [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 100 | 100 |
Underfunded Benefit Obligation |  |  |
Projected Benefit Obligation | 300 | 300 |
Accumulated Benefit Obligation | 100 | 100 |
Fair Value of Plan Assets | 0 | 0 |
Underfunded Status, Projected Benefit Obligation | (300) | (300) |
Underfunded Status, Accumulated Benefit Obligation | (100) | (100) |
Nonqualified Pension Plans [Member] | Public Service Co Of Oklahoma [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 1,200 | 1,200 |
Underfunded Benefit Obligation |  |  |
Projected Benefit Obligation | 1,400 | 1,500 |
Accumulated Benefit Obligation | 1,200 | 1,200 |
Fair Value of Plan Assets | 0 | 0 |
Underfunded Status, Projected Benefit Obligation | (1,400) | (1,500) |
Underfunded Status, Accumulated Benefit Obligation | (1,200) | (1,200) |
Nonqualified Pension Plans [Member] | Southwestern Electric Power Co [Member] |  |  |
Accumulated Benefit Obligation |  |  |
Accumulated Benefit Obligation | 1,000 | 1,100 |
Underfunded Benefit Obligation |  |  |
Accumulated Benefit Obligation | 1,000 | 1,100 |
Fair Value of Plan Assets | 227,500 | 231,300 |
Underfunded Status, Accumulated Benefit Obligation | (15,400) | (3,800) |
Other Postretirement Benefit Plans [Member] |  |  |
Underfunded Benefit Obligation |  |  |
Projected Benefit Obligation | 849,500 | 872,600 | 1,041,300
Fair Value of Plan Assets | 1,673,300 | 1,549,300 | 2,044,300
Estimated Future Benefit Payments and Contributions |  |  |
Expected Contributions and Payments During 2024 | 3,000 |  |
Components of Net Periodic Benefit Cost |  |  |
Service Cost | 4,600 | 7,400 | 9,500
Interest Cost | 46,200 | 29,200 | 30,500
Expected Return on Plan Assets | (109,600) | (110,000) | (91,100)
Amortization of Prior Service Cost (Credit) | (63,100) | (71,400) | (70,900)
Amortization of Net Actuarial Loss | 14,800 |  |
Net Periodic Benefit Cost (Credit) | (107,100) | (144,800) | (122,000)
Capitalized Portion | (2,100) | (3,200) | (4,100)
Net Periodic Benefit Cost (Credit) Recognized in Expense | (109,200) | (148,000) | (126,100)
Other Postretirement Benefit Plans [Member] | Benefit Payments [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 117,200 |  |
Year Two | 122,600 |  |
Year Three | 122,400 |  |
Year Four | 121,500 |  |
Year Five | 120,200 |  |
After Year Five for Next Five Years, in Total | 566,100 |  |
Other Postretirement Benefit Plans [Member] | Medicare Subsidy Receipts [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 300 |  |
Year Two | 300 |  |
Year Three | 300 |  |
Year Four | 300 |  |
Year Five | 300 |  |
After Year Five for Next Five Years, in Total | 1,500 |  |
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member] |  |  |
Underfunded Benefit Obligation |  |  |
Projected Benefit Obligation | 66,400 | 68,600 | 80,500
Fair Value of Plan Assets | 137,500 | 128,300 | 168,800
Estimated Future Benefit Payments and Contributions |  |  |
Expected Contributions and Payments During 2024 | 0 |  |
Components of Net Periodic Benefit Cost |  |  |
Service Cost | 300 | 500 | 700
Interest Cost | 3,600 | 2,200 | 2,400
Expected Return on Plan Assets | (9,000) | (9,100) | (7,500)
Amortization of Prior Service Cost (Credit) | (5,300) | (6,100) | (6,000)
Amortization of Net Actuarial Loss | 1,200 |  |
Net Periodic Benefit Cost (Credit) | (9,200) | (12,500) | (10,400)
Capitalized Portion | (200) | (300) | (400)
Net Periodic Benefit Cost (Credit) Recognized in Expense | (9,400) | (12,800) | (10,800)
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member] | Benefit Payments [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 9,400 |  |
Year Two | 10,000 |  |
Year Three | 10,200 |  |
Year Four | 10,200 |  |
Year Five | 9,900 |  |
After Year Five for Next Five Years, in Total | 45,200 |  |
Other Postretirement Benefit Plans [Member] | AEP Texas Inc. [Member] | Medicare Subsidy Receipts [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 0 |  |
Year Two | 0 |  |
Year Three | 0 |  |
Year Four | 0 |  |
Year Five | 0 |  |
After Year Five for Next Five Years, in Total | 0 |  |
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member] |  |  |
Underfunded Benefit Obligation |  |  |
Projected Benefit Obligation | 134,600 | 140,700 | 167,300
Fair Value of Plan Assets | 243,000 | 228,600 | 302,300
Estimated Future Benefit Payments and Contributions |  |  |
Expected Contributions and Payments During 2024 | 1,600 |  |
Components of Net Periodic Benefit Cost |  |  |
Service Cost | 500 | 800 | 1,000
Interest Cost | 7,400 | 4,700 | 4,900
Expected Return on Plan Assets | (16,100) | (16,300) | (13,500)
Amortization of Prior Service Cost (Credit) | (9,200) | (10,400) | (10,300)
Amortization of Net Actuarial Loss | 2,300 |  |
Net Periodic Benefit Cost (Credit) | (15,100) | (21,200) | (17,900)
Capitalized Portion | (200) | (400) | (400)
Net Periodic Benefit Cost (Credit) Recognized in Expense | (15,300) | (21,600) | (18,300)
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member] | Benefit Payments [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 18,800 |  |
Year Two | 19,400 |  |
Year Three | 19,300 |  |
Year Four | 19,100 |  |
Year Five | 19,000 |  |
After Year Five for Next Five Years, in Total | 88,300 |  |
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member] | Medicare Subsidy Receipts [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 100 |  |
Year Two | 100 |  |
Year Three | 100 |  |
Year Four | 100 |  |
Year Five | 100 |  |
After Year Five for Next Five Years, in Total | 500 |  |
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member] |  |  |
Underfunded Benefit Obligation |  |  |
Projected Benefit Obligation | 98,800 | 101,900 | 118,600
Fair Value of Plan Assets | 204,600 | 190,500 | 248,700
Estimated Future Benefit Payments and Contributions |  |  |
Expected Contributions and Payments During 2024 | 0 |  |
Components of Net Periodic Benefit Cost |  |  |
Service Cost | 600 | 900 | 1,300
Interest Cost | 5,400 | 3,400 | 3,500
Expected Return on Plan Assets | (13,500) | (13,700) | (11,100)
Amortization of Prior Service Cost (Credit) | (8,700) | (9,700) | (9,600)
Amortization of Net Actuarial Loss | 1,900 |  |
Net Periodic Benefit Cost (Credit) | (14,300) | (19,100) | (15,900)
Capitalized Portion | (200) | (300) | (400)
Net Periodic Benefit Cost (Credit) Recognized in Expense | (14,500) | (19,400) | (16,300)
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member] | Benefit Payments [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 15,200 |  |
Year Two | 15,700 |  |
Year Three | 15,700 |  |
Year Four | 15,400 |  |
Year Five | 15,000 |  |
After Year Five for Next Five Years, in Total | 69,700 |  |
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member] | Medicare Subsidy Receipts [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 0 |  |
Year Two | 0 |  |
Year Three | 0 |  |
Year Four | 0 |  |
Year Five | 0 |  |
After Year Five for Next Five Years, in Total | 0 |  |
Other Postretirement Benefit Plans [Member] | Ohio Power Co [Member] |  |  |
Underfunded Benefit Obligation |  |  |
Projected Benefit Obligation | 85,900 | 88,900 | 104,900
Fair Value of Plan Assets | 177,800 | 166,200 | 220,000
Estimated Future Benefit Payments and Contributions |  |  |
Expected Contributions and Payments During 2024 | 0 |  |
Components of Net Periodic Benefit Cost |  |  |
Service Cost | 400 | 600 | 800
Interest Cost | 4,700 | 3,000 | 3,000
Expected Return on Plan Assets | (11,800) | (12,000) | (9,700)
Amortization of Prior Service Cost (Credit) | (6,300) | (7,100) | (7,200)
Amortization of Net Actuarial Loss | 1,600 |  |
Net Periodic Benefit Cost (Credit) | (11,400) | (15,500) | (13,100)
Capitalized Portion | (200) | (300) | (400)
Net Periodic Benefit Cost (Credit) Recognized in Expense | (11,600) | (15,800) | (13,500)
Other Postretirement Benefit Plans [Member] | Ohio Power Co [Member] | Benefit Payments [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 12,600 |  |
Year Two | 13,000 |  |
Year Three | 12,800 |  |
Year Four | 12,700 |  |
Year Five | 12,500 |  |
After Year Five for Next Five Years, in Total | 57,600 |  |
Other Postretirement Benefit Plans [Member] | Ohio Power Co [Member] | Medicare Subsidy Receipts [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 0 |  |
Year Two | 0 |  |
Year Three | 0 |  |
Year Four | 0 |  |
Year Five | 0 |  |
After Year Five for Next Five Years, in Total | 0 |  |
Other Postretirement Benefit Plans [Member] | Public Service Co Of Oklahoma [Member] |  |  |
Underfunded Benefit Obligation |  |  |
Projected Benefit Obligation | 43,700 | 45,700 | 54,400
Fair Value of Plan Assets | 90,200 | 85,400 | 114,000
Estimated Future Benefit Payments and Contributions |  |  |
Expected Contributions and Payments During 2024 | 0 |  |
Components of Net Periodic Benefit Cost |  |  |
Service Cost | 300 | 400 | 600
Interest Cost | 2,400 | 1,500 | 1,600
Expected Return on Plan Assets | (5,900) | (6,100) | (5,000)
Amortization of Prior Service Cost (Credit) | (4,000) | (4,400) | (4,400)
Amortization of Net Actuarial Loss | 800 |  |
Net Periodic Benefit Cost (Credit) | (6,400) | (8,600) | (7,200)
Capitalized Portion | (100) | (200) | (300)
Net Periodic Benefit Cost (Credit) Recognized in Expense | (6,500) | (8,800) | (7,500)
Other Postretirement Benefit Plans [Member] | Public Service Co Of Oklahoma [Member] | Benefit Payments [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 6,700 |  |
Year Two | 7,100 |  |
Year Three | 7,000 |  |
Year Four | 6,800 |  |
Year Five | 6,500 |  |
After Year Five for Next Five Years, in Total | 30,200 |  |
Other Postretirement Benefit Plans [Member] | Public Service Co Of Oklahoma [Member] | Medicare Subsidy Receipts [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 0 |  |
Year Two | 0 |  |
Year Three | 0 |  |
Year Four | 0 |  |
Year Five | 0 |  |
After Year Five for Next Five Years, in Total | 0 |  |
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member] |  |  |
Underfunded Benefit Obligation |  |  |
Projected Benefit Obligation | 53,700 | 55,100 | 65,200
Fair Value of Plan Assets | 111,100 | 103,000 | 136,600
Estimated Future Benefit Payments and Contributions |  |  |
Expected Contributions and Payments During 2024 | 0 |  |
Components of Net Periodic Benefit Cost |  |  |
Service Cost | 400 | 600 | 800
Interest Cost | 2,900 | 1,800 | 1,900
Expected Return on Plan Assets | (7,200) | (7,300) | (6,100)
Amortization of Prior Service Cost (Credit) | (4,900) | (5,300) | (5,300)
Amortization of Net Actuarial Loss | 1,000 |  |
Net Periodic Benefit Cost (Credit) | (7,800) | (10,200) | (8,700)
Capitalized Portion | (200) | (200) | (300)
Net Periodic Benefit Cost (Credit) Recognized in Expense | (8,000) | $ (10,400) | $ (9,000)
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member] | Benefit Payments [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 7,800 |  |
Year Two | 8,300 |  |
Year Three | 8,300 |  |
Year Four | 8,100 |  |
Year Five | 8,200 |  |
After Year Five for Next Five Years, in Total | 38,800 |  |
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member] | Medicare Subsidy Receipts [Member] |  |  |
Estimated Future Benefit Payments and Contributions |  |  |
Year One | 0 |  |
Year Two | 0 |  |
Year Three | 0 |  |
Year Four | 0 |  |
Year Five | 0 |  |
After Year Five for Next Five Years, in Total | $ 0 |  |

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