Dispositions, Assets and Liabilities Held for Sale and Discontinued Operations (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Payment on Sale of Muskingum River Plant				$ 48
Gain on Disposition of Assets				32
Accounts Receivable		$ 55		55		$ 91
Property, Plant and Equipment		506		506		482
Other Classes of Assets That Are Not Major		47		47		52
Total Assets Classified as Held for Sale on the Condensed Consolidated Balance Sheets		608		608		625
Long-term Debt		81		81		83
Obligations Under Capital Leases		228		228		189
Other Classes of Liabilities That Are Not Major		165		165		163
Total Liabilities Classified as Held for Sale on the Condensed Consolidated Balance Sheets	[1]	474		474		$ 435
Other Revenues		129	$ 141	372	$ 435
Other Operation Expense		96	102	273	342
Maintenance Expense		4	8	20	24
Depreciation and Amortization Expense		9	8	27	23
Other Expense		8	7	24	22
Total Expense		117	125	344	411
Pretax Income of Discontinued Operations		12	16	28	24
Income Tax Expense		4	5	10	8
Total Income on Discontinued Operations as Presented on the Condensed Consolidated Statements of Income		$ 8	$ 11	$ 18	$ 16

[1] Amounts include debt related to AEPRO. See "AEPRO (AEP River Operations Segment)" section of Note 6 for additional information.