Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Operating Activities
Net Income (Loss)	$ 1,062,000	$ 952,000
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	1,011,000	934,000
Deferred Income Taxes	453,000	410,000
Carrying Costs Income	(17,000)	(15,000)
Allowance for Equity Funds Used During Construction	(64,000)	(47,000)
Mark-to-Market of Risk Management Contracts	(41,000)	9,000
Amortization of Nuclear Fuel	66,000	79,000
Pension Contributions to Qualified Plan Trust	(93,000)	(71,000)
Property Taxes	102,000	92,000
Fuel Over/Under-Recovery, Net	22,000	(105,000)
Deferral of Ohio Capacity Costs, Net	(1,000)	(99,000)
Change in Other Noncurrent Assets	(91,000)	11,000
Change in Other Noncurrent Liabilities	12,000	132,000
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	12,000	(73,000)
Fuel, Materials and Supplies	149,000	207,000
Accounts Payable	(10,000)	(39,000)
Accrued Taxes, Net	(115,000)	(86,000)
Other Current Assets	22,000	(3,000)
Other Current Liabilities	(276,000)	(91,000)
Net Cash Flows from (Used for) Operating Activities	2,203,000	2,197,000
Investing Activities
Construction Expenditures	(2,182,000)	(1,883,000)
Change in Other Temporary Investments, Net	30,000	(24,000)
Purchases of Investment Securities	(541,000)	(510,000)
Sales of Investment Securities	516,000	483,000
Acquisitions of Nuclear Fuel	(52,000)	(58,000)
Acquisitions of Assets/Businesses	(2,000)	(45,000)
Other Investing Activities	41,000	(31,000)
Net Cash Flows from (Used for) Investing Activities	(2,190,000)	(2,068,000)
Financing Activities
Issuance of Common Stock, Net	56,000	29,000
Issuance of Long-term Debt	2,603,000	939,000
Change in Short-term Debt, Net	(241,000)	725,000
Retirement of Long-term Debt	(1,727,000)	(1,205,000)
Make Whole Premium on Extinguishment of Long-term Debt	(93,000)	0
Principal Payments for Capital Lease Obligations	(57,000)	(60,000)
Dividends Paid on Common Stock	(522,000)	(490,000)
Other Financing Activities	0	5,000
Net Cash Flows from (Used for) Financing Activities	19,000	(57,000)
Net Increase (Decrease) in Cash and Cash Equivalents	32,000	72,000
Cash and Cash Equivalents at Beginning of Period	163,000	118,000
Cash and Cash Equivalents at End of Period	195,000	190,000
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	431,000	422,000
Net Cash Paid (Received) for Income Taxes	98,000	63,000
Noncash Acquisitions Under Capital Leases	76,000	33,000
Construction Expenditures Included in Current Liabilities as of June 30,	543,000	432,000
Construction Expenditures Included in Noncurrent Liabilities as of June 30,	66,000	0
Acquisition of Nuclear Fuel Included in Current Liabilities as of June 30,	0	42,000
Appalachian Power Co [Member]
Operating Activities
Net Income (Loss)	200,845	138,098
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	196,440	200,236
Deferred Income Taxes	122,498	90,236
Carrying Costs Income	(710)	1,612
Allowance for Equity Funds Used During Construction	(6,905)	(2,860)
Mark-to-Market of Risk Management Contracts	(15,664)	(6,025)
Pension Contributions to Qualified Plan Trust	(9,981)	(8,963)
Fuel Over/Under-Recovery, Net	(15,297)	(108,943)
Change in Other Noncurrent Assets	(1,845)	2,861
Change in Other Noncurrent Liabilities	(10,436)	23,626
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	18,911	93,553
Fuel, Materials and Supplies	15,489	69,120
Accounts Payable	(20,590)	(46,812)
Accrued Taxes, Net	(11,450)	(9,690)
Other Current Assets	(2,212)	(2,294)
Other Current Liabilities	(21,028)	(10,469)
Net Cash Flows from (Used for) Operating Activities	438,065	423,286
Investing Activities
Construction Expenditures	(293,100)	(224,879)
Change in Advances to Affiliates, Net	24,834	63,691
Other Investing Activities	7,012	(14,754)
Net Cash Flows from (Used for) Investing Activities	(261,254)	(175,942)
Financing Activities
Issuance of Long-term Debt	726,330	295,042
Change in Advances from Affiliates, Net	57,387	0
Retirement of Long-term Debt	(661,055)	(500,016)
Make Whole Premium on Extinguishment of Long-term Debt	(92,658)	0
Repayments of Related Party Debt	(86,000)	0
Principal Payments for Capital Lease Obligations	(2,571)	(2,904)
Dividends Paid on Common Stock	(118,750)	(40,000)
Other Financing Activities	416	1,002
Net Cash Flows from (Used for) Financing Activities	(176,901)	(246,876)
Net Increase (Decrease) in Cash and Cash Equivalents	(90)	468
Cash and Cash Equivalents at Beginning of Period	2,613	2,745
Cash and Cash Equivalents at End of Period	2,523	3,213
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	105,616	96,564
Net Cash Paid (Received) for Income Taxes	5,226	1,280
Noncash Acquisitions Under Capital Leases	1,880	3,133
Construction Expenditures Included in Current Liabilities as of June 30,	81,624	50,052
Indiana Michigan Power Co [Member]
Operating Activities
Net Income (Loss)	123,255	114,423
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	100,947	99,477
Deferred Income Taxes	48,011	17,499
Amortization (Deferral) of Incremental Nuclear Refueling Outage Expense, Net	(11,605)	28,358
Allowance for Equity Funds Used During Construction	(6,950)	(8,768)
Mark-to-Market of Risk Management Contracts	5,962	(4,378)
Amortization of Nuclear Fuel	65,514	78,560
Fuel Over/Under-Recovery, Net	(15,089)	14,567
Change in Other Noncurrent Assets	31,547	(42,263)
Change in Other Noncurrent Liabilities	(25,024)	44,269
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(2,250)	45,666
Fuel, Materials and Supplies	31,084	4,668
Accounts Payable	6,764	(26,859)
Accrued Taxes, Net	(7,778)	17,381
Other Current Assets	5,214	9,815
Other Current Liabilities	(37,109)	(22,913)
Net Cash Flows from (Used for) Operating Activities	312,493	369,502
Investing Activities
Construction Expenditures	(221,587)	(224,937)
Change in Advances to Affiliates, Net	(23)	42,357
Purchases of Investment Securities	(540,711)	(508,835)
Sales of Investment Securities	515,784	482,534
Acquisitions of Nuclear Fuel	(52,171)	(57,991)
Other Investing Activities	7,399	9,299
Net Cash Flows from (Used for) Investing Activities	(291,309)	(257,573)
Financing Activities
Issuance of Long-term Debt	210,702	99,419
Change in Advances from Affiliates, Net	(1,843)	47,353
Retirement of Long-term Debt	(150,077)	(160,292)
Principal Payments for Capital Lease Obligations	(20,181)	(23,622)
Dividends Paid on Common Stock	(60,000)	(75,000)
Other Financing Activities	512	554
Net Cash Flows from (Used for) Financing Activities	(20,887)	(111,588)
Net Increase (Decrease) in Cash and Cash Equivalents	297	341
Cash and Cash Equivalents at Beginning of Period	1,020	1,317
Cash and Cash Equivalents at End of Period	1,317	1,658
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	42,252	42,779
Net Cash Paid (Received) for Income Taxes	17,066	13,206
Noncash Acquisitions Under Capital Leases	1,384	3,918
Construction Expenditures Included in Current Liabilities as of June 30,	53,118	59,759
Acquisition of Nuclear Fuel Included in Current Liabilities as of June 30,	30	42,076
Expected Reimbursement for Spent Nuclear Fuel Dry Cask Storage	432	2,444
Ohio Power Co [Member]
Operating Activities
Net Income (Loss)	113,119	117,309
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	114,852	110,184
Amortization of Generation Deferrals	66,755	56,163
Deferred Income Taxes	15,527	41,576
Carrying Costs Income	(11,613)	(13,988)
Allowance for Equity Funds Used During Construction	(4,787)	(3,068)
Mark-to-Market of Risk Management Contracts	9,916	(6,379)
Pension Contributions to Qualified Plan Trust	(7,671)	(6,547)
Property Taxes	96,279	100,522
Fuel Over/Under-Recovery, Net	(22,931)	28,671
Deferral of Ohio Capacity Costs, Net	(30,662)	(120,743)
Change in Other Noncurrent Assets	23,865	13,281
Change in Other Noncurrent Liabilities	22,543	46,213
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	38,230	(2,256)
Fuel, Materials and Supplies	(14,687)	(4,205)
Accounts Payable	(68,105)	(70,228)
Customer Deposits	6,116	480
Accrued Taxes, Net	(99,683)	(138,584)
Other Current Assets	(787)	(560)
Other Current Liabilities	(30,230)	(24,522)
Net Cash Flows from (Used for) Operating Activities	216,046	123,319
Investing Activities
Construction Expenditures	(236,048)	(213,974)
Change in Restricted Cash for Securitized Funding	(12)	(23,616)
Change in Advances to Affiliates, Net	124,661	339,070
Proceeds from Notes Receivable Affiliated	86,000	139,450
Other Investing Activities	6,439	3,570
Net Cash Flows from (Used for) Investing Activities	(18,960)	244,500
Financing Activities
Change in Advances from Affiliates, Net	0	34,723
Retirement of Long-term Debt	(108,238)	(364,498)
Principal Payments for Capital Lease Obligations	(1,937)	(2,562)
Dividends Paid on Common Stock	(87,500)	(35,000)
Other Financing Activities	1,158	989
Net Cash Flows from (Used for) Financing Activities	(196,517)	(366,348)
Net Increase (Decrease) in Cash and Cash Equivalents	569	1,471
Cash and Cash Equivalents at Beginning of Period	2,870	3,004
Cash and Cash Equivalents at End of Period	3,439	4,475
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	61,278	69,127
Net Cash Paid (Received) for Income Taxes	20,500	10,863
Noncash Acquisitions Under Capital Leases	1,727	3,754
Construction Expenditures Included in Current Liabilities as of June 30,	42,222	40,878
Public Service Co Of Oklahoma [Member]
Operating Activities
Net Income (Loss)	40,783	30,897
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	59,316	48,589
Deferred Income Taxes	24,672	28,493
Allowance for Equity Funds Used During Construction	(3,610)	(2,021)
Mark-to-Market of Risk Management Contracts	(2,549)	578
Pension Contributions to Qualified Plan Trust	(5,795)	(4,439)
Property Taxes	(16,099)	(15,940)
Fuel Over/Under-Recovery, Net	51,593	(38,554)
Change in Other Noncurrent Assets	(14,048)	(10,411)
Change in Other Noncurrent Liabilities	4,492	(3,079)
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(5,989)	(4,382)
Fuel, Materials and Supplies	(463)	3,330
Accounts Payable	5,482	959
Accrued Taxes, Net	12,522	(1,116)
Other Current Assets	644	(1,386)
Other Current Liabilities	(3,582)	9,888
Net Cash Flows from (Used for) Operating Activities	147,369	41,406
Investing Activities
Construction Expenditures	(180,164)	(170,565)
Change in Advances to Affiliates, Net	(64,212)	0
Other Investing Activities	3,636	1,560
Net Cash Flows from (Used for) Investing Activities	(240,740)	(169,005)
Financing Activities
Issuance of Long-term Debt	248,785	74,975
Change in Advances from Affiliates, Net	(154,249)	88,028
Retirement of Long-term Debt	(212)	(33,906)
Principal Payments for Capital Lease Obligations	(1,762)	(1,731)
Other Financing Activities	730	583
Net Cash Flows from (Used for) Financing Activities	93,292	127,949
Net Increase (Decrease) in Cash and Cash Equivalents	(79)	350
Cash and Cash Equivalents at Beginning of Period	1,352	1,277
Cash and Cash Equivalents at End of Period	1,273	1,627
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	25,353	26,684
Net Cash Paid (Received) for Income Taxes	4,228	2,463
Noncash Acquisitions Under Capital Leases	1,389	1,190
Construction Expenditures Included in Current Liabilities as of June 30,	30,881	40,150
Southwestern Electric Power Co [Member]
Operating Activities
Net Income (Loss)	106,163	55,785
Adjustments to Reconcile Net Income to Net Cash Flows from (Used for) Operating Activities:
Depreciation and Amortization	94,918	91,525
Deferred Income Taxes	31,457	179,336
Allowance for Equity Funds Used During Construction	(11,111)	(4,278)
Mark-to-Market of Risk Management Contracts	(639)	593
Pension Contributions to Qualified Plan Trust	(8,052)	(3,832)
Property Taxes	(26,093)	(25,053)
Fuel Over/Under-Recovery, Net	4,906	(18,825)
Change in Other Noncurrent Assets	(4,443)	8,034
Change in Other Noncurrent Liabilities	(454)	(3,464)
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(14,732)	21,194
Fuel, Materials and Supplies	12,153	22,914
Accounts Payable	(3,174)	8,186
Accrued Taxes, Net	36,579	(108,460)
Other Current Assets	1,428	(3,310)
Other Current Liabilities	(40,627)	(10,700)
Net Cash Flows from (Used for) Operating Activities	178,279	209,645
Investing Activities
Construction Expenditures	(268,423)	(220,968)
Change in Advances to Affiliates, Net	(138,676)	0
Other Investing Activities	2,138	3,394
Net Cash Flows from (Used for) Investing Activities	(404,961)	(217,574)
Financing Activities
Issuance of Long-term Debt	445,949	0
Change in Advances from Affiliates, Net	0	69,918
Retirement of Long-term Debt	(155,125)	(1,625)
Principal Payments for Capital Lease Obligations	(9,138)	(9,156)
Dividends Paid on Common Stock	(60,000)	(50,000)
Dividends Paid on Common Stock	(2,107)	(2,309)
Other Financing Activities	764	831
Net Cash Flows from (Used for) Financing Activities	220,343	7,659
Net Increase (Decrease) in Cash and Cash Equivalents	(6,339)	(270)
Cash and Cash Equivalents at Beginning of Period	14,356	17,241
Cash and Cash Equivalents at End of Period	8,017	16,971
Supplementary Information
Cash Paid for Interest, Net of Capitalized Amounts	55,799	60,001
Net Cash Paid (Received) for Income Taxes	9,628	(7,556)
Noncash Acquisitions Under Capital Leases	1,162	3,354
Construction Expenditures Included in Current Liabilities as of June 30,	$ 73,626	$ 63,813