Business Segments (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
Reportable Segment Information
Revenues		$ 4,432	$ 4,161		$ 12,839	$ 12,559
Income from Continuing Operations		512	483		1,564	1,430
Income from Discontinued Operations, Net of Tax		8	11		18	16
NET INCOME (LOSS)		520	494		1,582	1,446
Balance Sheet Information
Total Property, Plant and Equipment		64,826			64,826			$ 63,606
Accumulated Depreciation and Amortization		19,588			19,588			19,971
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		45,238			45,238			43,635
Assets Held for Sale		608			608			625
Total Assets		61,099			61,099			59,633
Long-term Debt Due Within One Year - Affiliated		0			0			0
Long-term Debt Due Within One Year		1,826			1,826			2,500
Long-term Debt - Affiliated		0			0			0
Long-term Debt		17,600			17,600			16,101
Total Long-term Debt Outstanding		19,426			19,426			18,601
Liabilities Held for Sale	[1]	474			474			435
Reconciling Adjustments [Member]
Reportable Segment Information
NET INCOME (LOSS)		0	0		0	0
Balance Sheet Information
Total Property, Plant and Equipment	[2]	(279)			(279)			(271)
Accumulated Depreciation and Amortization	[2]	(109)			(109)			(99)
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	[2]	(170)			(170)			(172)
Assets Held for Sale		0			0			0
Total Assets	[2],[3]	(21,089)			(21,089)			(20,346)
Long-term Debt Due Within One Year - Affiliated		0			0			(197)
Long-term Debt Due Within One Year		0			0			0
Long-term Debt - Affiliated		(52)			(52)			(52)
Long-term Debt		0			0			0
Total Long-term Debt Outstanding		(52)			(52)			(249)
Liabilities Held for Sale		0			0			0
Vertically Integrated Utilities [Member]
Reportable Segment Information
Sales Revenue, Net		2,436	2,432	[4]	7,082	7,217	[4]
Revenues		2,471	2,450		7,159	7,288
Income from Continuing Operations		275	220		783	654
Income from Discontinued Operations, Net of Tax		0	0		0	0
NET INCOME (LOSS)		275	220		783	654
Balance Sheet Information
Total Property, Plant and Equipment		39,981			39,981			39,402
Accumulated Depreciation and Amortization		12,483			12,483			12,773
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		27,498			27,498			26,629
Assets Held for Sale		0			0			0
Total Assets		35,272			35,272			33,750
Long-term Debt Due Within One Year - Affiliated		0			0			111
Long-term Debt Due Within One Year		949			949			1,352
Long-term Debt - Affiliated		20			20			20
Long-term Debt		9,900			9,900			8,634
Total Long-term Debt Outstanding		10,869			10,869			10,117
Liabilities Held for Sale		0			0			0
Vertically Integrated Utilities [Member] | Significant Reconciling Items [Member]
Reportable Segment Information
Sales Revenue, Net		35	18	[4]	77	71	[4]
Transmission And Distribution Utilities [Member]
Reportable Segment Information
Sales Revenue, Net		1,164	1,163		3,378	3,388
Revenues		1,189	1,231		3,520	3,580
Income from Continuing Operations		113	92		288	279
Income from Discontinued Operations, Net of Tax		0	0		0	0
NET INCOME (LOSS)		113	92		288	279
Balance Sheet Information
Total Property, Plant and Equipment		13,707			13,707			13,024
Accumulated Depreciation and Amortization		3,603			3,603			3,481
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		10,104			10,104			9,543
Assets Held for Sale		0			0			0
Total Assets		14,441			14,441			14,495
Long-term Debt Due Within One Year - Affiliated		0			0			0
Long-term Debt Due Within One Year		724			724			405
Long-term Debt - Affiliated		0			0			0
Long-term Debt		4,888			4,888			5,256
Total Long-term Debt Outstanding		5,612			5,612			5,661
Liabilities Held for Sale		0			0			0
Transmission And Distribution Utilities [Member] | Significant Reconciling Items [Member]
Reportable Segment Information
Sales Revenue, Net		25	68		142	192
AEP Transmission Holdco [Member]
Reportable Segment Information
Sales Revenue, Net		27	21		74	54
Revenues		88	55		245	140
Income from Continuing Operations		46	43		148	114
Income from Discontinued Operations, Net of Tax		0	0		0	0
NET INCOME (LOSS)		46	43		148	114
Balance Sheet Information
Total Property, Plant and Equipment		3,594			3,594			2,714
Accumulated Depreciation and Amortization		43			43			25
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		3,551			3,551			2,689
Assets Held for Sale		0			0			0
Total Assets		4,362			4,362			3,575
Long-term Debt Due Within One Year - Affiliated		0			0			0
Long-term Debt Due Within One Year		0			0			0
Long-term Debt - Affiliated		0			0			0
Long-term Debt		1,323			1,323			1,153
Total Long-term Debt Outstanding		1,323			1,323			1,153
Liabilities Held for Sale		0			0			0
AEP Transmission Holdco [Member] | Significant Reconciling Items [Member]
Reportable Segment Information
Sales Revenue, Net		61	34		171	86
Generation And Marketing [Member]
Reportable Segment Information
Sales Revenue, Net		802	538	[4]	2,289	1,932	[4]
Revenues		835	901		2,806	3,065
Income from Continuing Operations		91	117		360	378
Income from Discontinued Operations, Net of Tax		0	0		0	0
NET INCOME (LOSS)		91	117		360	378
Balance Sheet Information
Total Property, Plant and Equipment		7,474			7,474			8,394
Accumulated Depreciation and Amortization		3,390			3,390			3,603
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		4,084			4,084			4,791
Assets Held for Sale		0			0			0
Total Assets		5,531			5,531			6,329
Long-term Debt Due Within One Year - Affiliated		0			0			86
Long-term Debt Due Within One Year		151			151			740
Long-term Debt - Affiliated		32			32			32
Long-term Debt		641			641			217
Total Long-term Debt Outstanding		824			824			1,075
Liabilities Held for Sale		0			0			0
Generation And Marketing [Member] | Significant Reconciling Items [Member]
Reportable Segment Information
Sales Revenue, Net		33	363	[4]	517	1,133	[4]
AEP River Operations [Member]
Reportable Segment Information
Sales Revenue, Net		0	0		0	0
Revenues		0	0		0	0
Income from Continuing Operations		(4)	0		(2)	1
Income from Discontinued Operations, Net of Tax		8	11		18	16
NET INCOME (LOSS)		4	11		16	17
Balance Sheet Information
Total Property, Plant and Equipment		0			0			0
Accumulated Depreciation and Amortization		0			0			0
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET		0			0			0
Assets Held for Sale		608			608			625
Total Assets	[5]	772			772			749
Long-term Debt Due Within One Year - Affiliated		0			0			0
Long-term Debt Due Within One Year		0			0			0
Long-term Debt - Affiliated		0			0			0
Long-term Debt		0			0			0
Total Long-term Debt Outstanding		0			0			0
Liabilities Held for Sale		474			474			435
AEP River Operations [Member] | Significant Reconciling Items [Member]
Reportable Segment Information
Sales Revenue, Net		0	0		0	0
All Other [Member]
Reportable Segment Information
Sales Revenue, Net	[6]	3	7		16	19
Revenues	[6]	24	26		74	74
Income from Continuing Operations	[6]	(9)	11		(13)	4
Income from Discontinued Operations, Net of Tax	[6]	0	0		0	0
NET INCOME (LOSS)	[6]	(9)	11		(13)	4
Balance Sheet Information
Total Property, Plant and Equipment	[6]	349			349			343
Accumulated Depreciation and Amortization	[6]	178			178			188
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	[6]	171			171			155
Assets Held for Sale	[6]	0			0			0
Total Assets	[6]	21,810			21,810			21,081
Long-term Debt Due Within One Year - Affiliated	[6]	0			0			0
Long-term Debt Due Within One Year	[6]	2			2			3
Long-term Debt - Affiliated	[6]	0			0			0
Long-term Debt	[6]	848			848			841
Total Long-term Debt Outstanding	[6]	850			850			844
Liabilities Held for Sale	[6]	0			0			$ 0
All Other [Member] | Significant Reconciling Items [Member]
Reportable Segment Information
Sales Revenue, Net	[6]	21	19		58	55
Consolidation, Eliminations [Member]
Reportable Segment Information
Sales Revenue, Net	[7]	0	0		0	(51)
Revenues		(175)	(502)		(965)	(1,588)
Income from Continuing Operations		0	0		0	0
Income from Discontinued Operations, Net of Tax		0	0		0	0
Consolidation, Eliminations [Member] | Reconciling Adjustments [Member]
Reportable Segment Information
Sales Revenue, Net		$ (175)	$ (502)		$ (965)	$ (1,537)

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

[2] Includes eliminations due to an intercompany capital lease.

[3] Reconciling Adjustments for Total Assets primarily include the elimination of intercompany advances to affiliates and intercompany accounts receivable along with the elimination of AEP's investments in subsidiary companies.

[4] Includes the impact of corporate separation of OPCo's generation assets and liabilities that took effect December 31, 2013, as well as the impact of the termination of the Interconnection Agreement effective January 1, 2014.

[5] Amounts include intercompany advances to affiliates and intercompany accounts receivable that will be settled prior to or upon the close of the sale of AEPRO.

[6] Corporate and Other primarily includes the purchasing of receivables from certain AEP utility subsidiaries. This segment also includes Parent's guarantee revenue received from affiliates, investment income, interest income and interest expense and other nonallocated costs.

[7] Reconciling Adjustments for External Customers primarily include eliminations as a result of corporate separation in Ohio.