Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Operating Activities
Net Income (Loss)	$ 1,005.7	$ 400.4
Adjustments to Reconcile Net Income (Loss) to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	787.1	775.5
Deferred Income Taxes	(113.3)	68.0
Allowance for Equity Funds Used During Construction	(43.6)	(31.3)
Mark-to-Market of Risk Management Contracts	40.9	(82.0)
Property Taxes	(89.2)	(101.6)
Deferred Fuel Over/Under-Recovery, Net	43.4	128.0
Change in Other Noncurrent Assets	(74.5)	(96.0)
Change in Other Noncurrent Liabilities	61.8	(58.7)
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	34.9	348.4
Fuel, Materials and Supplies	104.3	(115.9)
Accounts Payable	(99.5)	(255.9)
Accrued Taxes, Net	(57.7)	(150.9)
Other Current Assets	(91.3)	(94.6)
Other Current Liabilities	(66.8)	(127.6)
Net Cash Flows from (Used for) Operating Activities	1,442.2	717.8
Investing Activities
Construction Expenditures	(1,761.7)	(2,090.1)
Purchases of Investment Securities	(590.0)	(537.3)
Sales of Investment Securities	572.5	517.6
Acquisitions of Nuclear Fuel	(33.7)	(1.7)
Proceeds from Sale of Equity Method Investments	114.0	0.0
Other Investing Activities	29.6	12.0
Net Cash Flows from (Used for) Investing Activities	(1,669.3)	(2,245.2)
Financing Activities
Issuance of Common Stock	40.6	41.1
Issuance of Long-term Debt	859.9	2,847.3
Issuance of Short-term Debt with Original Maturities greater than 90 Days	376.6	97.4
Change in Short-term Debt with Original Maturities less than 90 Days, Net	840.9	(433.7)
Retirement of Long-term Debt	(1,162.2)	(519.5)
Redemption of Short-term Debt with Original Maturities Greater than 90 Days	(310.1)	(153.8)
Principal Payments for Finance Leases Obligations	(17.0)	(26.8)
Dividends Paid on Common Stock	(466.9)	(431.8)
Other Financing Activities	(31.9)	(55.8)
Net Cash Flows from (Used for) Financing Activities	129.9	1,364.4
Net Increase (Decrease) in Cash and Cash Equivalents	(97.2)	(163.0)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	379.0	556.5
Cash and Cash Equivalents at Beginning of Period	330.1
Cash, Cash Equivalents and Restricted Cash at End of Period	281.8	393.5
Cash and Cash Equivalents at End of Period	230.7
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	368.3	311.9
Net Cash Paid (Received) for Income Taxes	16.1	15.8
Cash Received from Sale of Transferable Tax Credits	(62.0)	0.0
Noncash Acquisitions Under Finance Leases	7.0	12.5
Construction Expenditures Included in Current Liabilities as of March 31,	837.0	1,076.1
Forward Equity Purchase Contract Included in Current and Noncurrent Liabilities as of September 30,	14.8	12.5
Renewable Energy Facilities
Investing Activities
Acquisitions of Renewable Energy Facilities	0.0	(145.7)
Competitive Contracted Renewable Portfolio
Adjustments to Reconcile Net Income (Loss) to Net Cash Flows from (Used for) Operating Activities:
Loss on the Expected/Completed Sale	0.0	112.0
AEP Texas Inc. [Member]
Operating Activities
Net Income (Loss)	79.7	47.6
Adjustments to Reconcile Net Income (Loss) to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	116.7	111.0
Deferred Income Taxes	6.6	6.4
Allowance for Equity Funds Used During Construction	(8.6)	(6.3)
Mark-to-Market of Risk Management Contracts	(0.2)	0.4
Property Taxes	(84.3)	(88.8)
Change in Other Noncurrent Assets	(17.2)	(18.3)
Change in Other Noncurrent Liabilities	3.0	(0.8)
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	7.8	24.6
Fuel, Materials and Supplies	(3.6)	(1.1)
Accounts Payable	11.6	3.6
Accrued Taxes, Net	42.6	44.5
Accrued Interest	32.3	23.9
Other Current Assets	1.4	0.9
Other Current Liabilities	(20.0)	(10.9)
Net Cash Flows from (Used for) Operating Activities	167.8	136.7
Investing Activities
Construction Expenditures	(331.2)	(450.4)
Change in Advances to Affiliates, Net	0.1	0.1
Other Investing Activities	21.1	7.3
Net Cash Flows from (Used for) Investing Activities	(310.0)	(443.0)
Financing Activities
Capital Contributions from Parent	0.0	100.0
Change in Advances from Affiliates, Net	164.2	354.3
Retirement of Long-term Debt	(11.9)	(136.7)
Principal Payments for Finance Leases Obligations	(1.8)	(1.8)
Other Financing Activities	0.4	0.3
Net Cash Flows from (Used for) Financing Activities	150.9	316.1
Net Increase (Decrease) in Cash and Cash Equivalents	8.7	9.8
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	34.1	32.8
Cash and Cash Equivalents at Beginning of Period	0.1
Cash, Cash Equivalents and Restricted Cash at End of Period	42.8	42.6
Cash and Cash Equivalents at End of Period	0.1
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	26.9	31.6
Noncash Acquisitions Under Finance Leases	1.1	1.8
Construction Expenditures Included in Current Liabilities as of March 31,	158.3	177.5
AEP Texas Inc. [Member] | Retained Earnings [Member]
Operating Activities
Net Income (Loss)	79.7	47.6
AEP Transmission Co [Member]
Operating Activities
Net Income (Loss)	181.2	162.7
Adjustments to Reconcile Net Income (Loss) to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	105.9	95.2
Deferred Income Taxes	25.0	20.6
Allowance for Equity Funds Used During Construction	(17.9)	(16.4)
Property Taxes	36.3	34.6
Provision for Refund Affiliated	6.0	4.8
Change in Other Noncurrent Assets	(0.4)	0.9
Change in Other Noncurrent Liabilities	(6.1)	6.6
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(4.0)	(12.5)
Fuel, Materials and Supplies	0.0	(4.1)
Accounts Payable	5.4	41.0
Accrued Taxes, Net	(63.2)	(59.9)
Other Current Assets	1.0	1.0
Other Current Liabilities	10.8	29.6
Net Cash Flows from (Used for) Operating Activities	274.0	299.3
Investing Activities
Construction Expenditures	(336.5)	(439.7)
Change in Advances to Affiliates, Net	(230.9)	(293.1)
Other Investing Activities	7.8	(0.8)
Net Cash Flows from (Used for) Investing Activities	(559.6)	(733.6)
Financing Activities
Capital Contributions from Parent	25.0	25.0
Issuance of Long-term Debt	446.1	689.2
Change in Advances from Affiliates, Net	(145.5)	(224.9)
Dividends Paid on Common Stock	(40.0)	(55.0)
Net Cash Flows from (Used for) Financing Activities	285.6	434.3
Net Increase (Decrease) in Cash and Cash Equivalents	0.0	0.0
Cash and Cash Equivalents at Beginning of Period	0.0	0.0
Cash and Cash Equivalents at End of Period	0.0	0.0
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	33.3	16.2
Construction Expenditures Included in Current Liabilities as of March 31,	191.0	305.4
AEP Transmission Co [Member] | Retained Earnings [Member]
Operating Activities
Net Income (Loss)	181.2	162.7
Financing Activities
Dividends Paid on Common Stock	(40.0)	(55.0)
Appalachian Power Co [Member]
Operating Activities
Net Income (Loss)	136.5	112.5
Adjustments to Reconcile Net Income (Loss) to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	149.8	143.0
Deferred Income Taxes	(12.8)	10.3
Allowance for Equity Funds Used During Construction	(2.9)	(2.4)
Mark-to-Market of Risk Management Contracts	11.8	60.1
Deferred Fuel Over/Under-Recovery, Net	62.4	26.0
Change in Other Noncurrent Assets	3.9	(5.5)
Change in Other Noncurrent Liabilities	6.5	(33.0)
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(10.6)	54.5
Fuel, Materials and Supplies	30.0	(59.3)
Increase (Decrease) in Margin Deposits Outstanding	11.0	(11.1)
Accounts Payable	(24.7)	(156.1)
Accrued Taxes, Net	33.0	23.6
Other Current Assets	0.0	2.9
Other Current Liabilities	12.4	(1.2)
Net Cash Flows from (Used for) Operating Activities	406.3	164.3
Investing Activities
Construction Expenditures	(236.0)	(287.4)
Change in Advances to Affiliates, Net	(18.5)	1.1
Other Investing Activities	3.6	1.5
Net Cash Flows from (Used for) Investing Activities	(250.9)	(284.8)
Financing Activities
Capital Contributions from Parent	100.0	0.0
Issuance of Long-term Debt	395.8	0.0
Change in Advances from Affiliates, Net	(339.6)	128.0
Retirement of Long-term Debt	(313.4)	(13.0)
Principal Payments for Finance Leases Obligations	(2.2)	(2.0)
Other Financing Activities	0.1	0.2
Net Cash Flows from (Used for) Financing Activities	(159.3)	113.2
Net Increase (Decrease) in Cash and Cash Equivalents	(3.9)	(7.3)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	19.9	21.9
Cash and Cash Equivalents at Beginning of Period	5.0
Cash, Cash Equivalents and Restricted Cash at End of Period	16.0	14.6
Cash and Cash Equivalents at End of Period	7.6
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	41.5	37.9
Noncash Acquisitions Under Finance Leases	0.3	0.6
Construction Expenditures Included in Current Liabilities as of March 31,	107.3	122.6
Appalachian Power Co [Member] | Retained Earnings [Member]
Operating Activities
Net Income (Loss)	136.5	112.5
Indiana Michigan Power Co [Member]
Operating Activities
Net Income (Loss)	145.0	102.8
Adjustments to Reconcile Net Income (Loss) to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	108.3	125.2
Deferred Income Taxes	(60.3)	(3.3)
Amortization (Deferral) of Incremental Nuclear Refueling Outage Expenses, Net	(11.8)	18.1
Allowance for Equity Funds Used During Construction	(3.3)	(0.5)
Mark-to-Market of Risk Management Contracts	27.1	8.8
Amortization of Nuclear Fuel	24.4	25.0
Deferred Fuel Over/Under-Recovery, Net	10.1	3.8
Change in Other Noncurrent Assets	(34.0)	(4.3)
Change in Other Noncurrent Liabilities	35.3	3.7
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(2.1)	52.7
Fuel, Materials and Supplies	21.3	(24.1)
Accounts Payable	(13.5)	(27.8)
Accrued Taxes, Net	28.8	21.1
Other Current Assets	11.9	(1.9)
Other Current Liabilities	(37.3)	(41.8)
Net Cash Flows from (Used for) Operating Activities	249.9	257.5
Investing Activities
Construction Expenditures	(142.3)	(141.7)
Change in Advances to Affiliates, Net	0.0	(37.0)
Purchases of Investment Securities	(588.5)	(536.3)
Sales of Investment Securities	569.5	517.6
Acquisitions of Nuclear Fuel	(33.7)	(1.7)
Other Investing Activities	2.7	3.3
Net Cash Flows from (Used for) Investing Activities	(192.3)	(195.8)
Financing Activities
Issuance of Long-term Debt	0.0	499.8
Change in Advances from Affiliates, Net	9.9	(249.9)
Retirement of Long-term Debt	(25.4)	(274.3)
Principal Payments for Finance Leases Obligations	(1.6)	(1.9)
Dividends Paid on Common Stock	(37.5)	(31.2)
Other Financing Activities	0.4	0.1
Net Cash Flows from (Used for) Financing Activities	(54.2)	(57.4)
Net Increase (Decrease) in Cash and Cash Equivalents	3.4	4.3
Cash and Cash Equivalents at Beginning of Period	2.1	4.2
Cash and Cash Equivalents at End of Period	5.5	8.5
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	38.7	44.4
Net Cash Paid (Received) for Income Taxes	0.0	2.4
Noncash Acquisitions Under Finance Leases	0.5	2.2
Construction Expenditures Included in Current Liabilities as of March 31,	63.1	61.3
Indiana Michigan Power Co [Member] | Retained Earnings [Member]
Operating Activities
Net Income (Loss)	145.0	102.8
Ohio Power Co [Member]
Operating Activities
Net Income (Loss)	70.6	78.0
Adjustments to Reconcile Net Income (Loss) to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	105.8	75.2
Deferred Income Taxes	(0.6)	2.1
Allowance for Equity Funds Used During Construction	(5.5)	(2.8)
Mark-to-Market of Risk Management Contracts	(9.7)	7.2
Property Taxes	95.0	92.0
Change in Other Noncurrent Assets	10.1	(43.2)
Change in Other Noncurrent Liabilities	11.4	(21.7)
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(40.2)	(20.3)
Fuel, Materials and Supplies	(1.1)	(4.8)
Accounts Payable	(32.4)	(5.5)
Increase (Decrease) in Contract with Customer, Liability	14.2	(22.7)
Accrued Taxes, Net	(157.5)	(157.9)
Other Current Assets	(3.4)	(2.2)
Other Current Liabilities	1.5	(7.7)
Net Cash Flows from (Used for) Operating Activities	58.2	(34.3)
Investing Activities
Construction Expenditures	(241.1)	(262.0)
Other Investing Activities	5.2	4.9
Net Cash Flows from (Used for) Investing Activities	(235.9)	(257.1)
Financing Activities
Capital Contributions from Parent	0.0	50.0
Change in Advances from Affiliates, Net	184.7	241.7
Principal Payments for Finance Leases Obligations	(1.3)	(1.2)
Other Financing Activities	0.4	0.4
Net Cash Flows from (Used for) Financing Activities	183.8	290.9
Net Increase (Decrease) in Cash and Cash Equivalents	6.1	(0.5)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	6.4	9.6
Cash and Cash Equivalents at Beginning of Period	6.4
Cash, Cash Equivalents and Restricted Cash at End of Period	12.5	9.1
Cash and Cash Equivalents at End of Period	12.5
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	19.1	20.9
Noncash Acquisitions Under Finance Leases	0.5	0.6
Construction Expenditures Included in Current Liabilities as of March 31,	104.8	109.9
Ohio Power Co [Member] | Retained Earnings [Member]
Operating Activities
Net Income (Loss)	70.6	78.0
Public Service Co Of Oklahoma [Member]
Operating Activities
Net Income (Loss)	72.0	(2.3)
Adjustments to Reconcile Net Income (Loss) to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	67.4	61.1
Deferred Income Taxes	(15.5)	12.2
Allowance for Equity Funds Used During Construction	(2.4)	(1.5)
Mark-to-Market of Risk Management Contracts	12.5	13.9
Property Taxes	(45.9)	(45.6)
Deferred Fuel Over/Under-Recovery, Net	(37.6)	49.4
Change in Other Noncurrent Assets	(18.4)	(9.7)
Change in Other Noncurrent Liabilities	1.7	1.4
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(4.8)	27.2
Fuel, Materials and Supplies	(2.9)	12.9
Accounts Payable	(4.5)	(62.8)
Accrued Taxes, Net	23.9	24.9
Other Current Assets	(16.1)	0.4
Other Current Liabilities	(46.9)	(7.5)
Net Cash Flows from (Used for) Operating Activities	(17.5)	74.0
Investing Activities
Construction Expenditures	(156.9)	(146.8)
Other Investing Activities	1.0	0.4
Net Cash Flows from (Used for) Investing Activities	(155.9)	(292.1)
Financing Activities
Issuance of Long-term Debt	0.0	469.9
Change in Advances from Affiliates, Net	210.2	(233.5)
Retirement of Long-term Debt	(0.1)	(0.1)
Principal Payments for Finance Leases Obligations	(0.8)	(0.8)
Dividends Paid on Common Stock	(35.0)	(17.5)
Other Financing Activities	0.1	(0.1)
Net Cash Flows from (Used for) Financing Activities	174.4	217.9
Net Increase (Decrease) in Cash and Cash Equivalents	1.0	(0.2)
Cash and Cash Equivalents at Beginning of Period	2.5	4.0
Cash and Cash Equivalents at End of Period	3.5	3.8
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	30.3	22.3
Cash Received from Sale of Transferable Tax Credits	(24.9)	0.0
Noncash Acquisitions Under Finance Leases	0.4	0.2
Construction Expenditures Included in Current Liabilities as of March 31,	47.9	63.4
Public Service Co Of Oklahoma [Member] | Renewable Energy Facilities
Investing Activities
Acquisitions of Renewable Energy Facilities	0.0	(145.7)
Public Service Co Of Oklahoma [Member] | Retained Earnings [Member]
Operating Activities
Net Income (Loss)	72.0	(2.3)
Southwestern Electric Power Co [Member]
Operating Activities
Net Income (Loss)	209.6	41.8
Adjustments to Reconcile Net Income (Loss) to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	78.7	80.4
Deferred Income Taxes	(118.5)	10.8
Allowance for Equity Funds Used During Construction	(3.4)	(0.5)
Mark-to-Market of Risk Management Contracts	1.7	9.9
Property Taxes	(74.3)	(77.5)
Deferred Fuel Over/Under-Recovery, Net	22.8	42.9
Change in Other Noncurrent Assets	(10.2)	7.2
Change in Other Noncurrent Liabilities	(0.3)	(3.3)
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(9.7)	29.9
Fuel, Materials and Supplies	9.4	(4.3)
Accounts Payable	(29.6)	(47.8)
Accrued Taxes, Net	67.0	62.3
Other Current Assets	(17.7)	7.3
Other Current Liabilities	(55.7)	(48.9)
Net Cash Flows from (Used for) Operating Activities	69.8	110.2
Investing Activities
Construction Expenditures	(182.6)	(201.9)
Change in Advances to Affiliates, Net	(0.1)	0.0
Other Investing Activities	3.0	0.4
Net Cash Flows from (Used for) Investing Activities	(179.7)	(201.5)
Financing Activities
Capital Contributions from Parent	0.0	50.0
Issuance of Long-term Debt	0.0	347.3
Change in Short-term Debt with Original Maturities less than 90 Days, Net	1.1	16.0
Change in Advances from Affiliates, Net	165.8	(291.9)
Retirement of Long-term Debt	0.0	(94.1)
Principal Payments for Finance Leases Obligations	(4.4)	(14.8)
Dividends Paid on Common Stock	(50.0)	0.0
Dividends Paid on Common Stock	(1.4)	(1.5)
Other Financing Activities	0.2	0.1
Net Cash Flows from (Used for) Financing Activities	111.3	11.1
Net Increase (Decrease) in Cash and Cash Equivalents	1.4	(80.2)
Cash and Cash Equivalents at Beginning of Period	2.4	88.4
Cash and Cash Equivalents at End of Period	3.8	8.2
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	41.2	45.3
Cash Received from Sale of Transferable Tax Credits	(19.9)	0.0
Noncash Acquisitions Under Finance Leases	0.4	0.9
Construction Expenditures Included in Current Liabilities as of March 31,	$ 79.4	$ 113.3