Business Segments (Details) (USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013		Dec. 31, 2013
Reportable Segment Information
Revenues	$ 4,302,000,000		$ 4,176,000,000		$ 12,994,000,000		$ 11,584,000,000
NET INCOME (LOSS)	494,000,000		434,000,000		1,446,000,000		1,137,000,000
Balance Sheet Information
Total Property, Plant and Equipment	63,123,000,000				63,123,000,000				60,285,000,000
Accumulated Depreciation and Amortization	20,059,000,000				20,059,000,000				19,288,000,000
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	43,064,000,000				43,064,000,000				40,997,000,000
Total Assets	57,925,000,000				57,925,000,000				56,414,000,000
Long-term Debt Due Within One Year - Affiliated	0				0				0
Long-term Debt Due Within One Year	2,381,000,000				2,381,000,000				1,549,000,000
Long-term Debt - Affiliated	0				0				0
Long-term Debt	15,677,000,000				15,677,000,000				16,828,000,000
Total Long-term Debt Outstanding	18,058,000,000				18,058,000,000				18,377,000,000
Reconciling Adjustments [Member]
Reportable Segment Information
NET INCOME (LOSS)	0		0		0		0
Balance Sheet Information
Total Property, Plant and Equipment	(271,000,000)	[1]			(271,000,000)	[1]			(269,000,000)	[1]
Accumulated Depreciation and Amortization	(94,000,000)	[1]			(94,000,000)	[1]			(85,000,000)	[1]
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	(177,000,000)	[1]			(177,000,000)	[1]			(184,000,000)	[1]
Total Assets	(19,641,000,000)	[1],[2]			(19,641,000,000)	[1],[2]			(19,531,000,000)	[1],[2]
Long-term Debt Due Within One Year - Affiliated	(217,000,000)				(217,000,000)				(184,000,000)
Long-term Debt Due Within One Year	0				0				0
Long-term Debt - Affiliated	(52,000,000)				(52,000,000)				(279,000,000)
Long-term Debt	0				0				0
Total Long-term Debt Outstanding	(269,000,000)				(269,000,000)				(463,000,000)
Vertically Integrated Utilities [Member]
Reportable Segment Information
Sales Revenue, Net	2,432,000,000	[3]	2,543,000,000		7,217,000,000	[3]	7,075,000,000
Revenues	2,450,000,000		2,738,000,000		7,288,000,000		7,555,000,000
NET INCOME (LOSS)	220,000,000		174,000,000		654,000,000		508,000,000
Balance Sheet Information
Total Property, Plant and Equipment	38,857,000,000				38,857,000,000				37,545,000,000
Accumulated Depreciation and Amortization	12,728,000,000				12,728,000,000				12,250,000,000
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	26,129,000,000				26,129,000,000				25,295,000,000
Total Assets	33,072,000,000				33,072,000,000				32,791,000,000
Long-term Debt Due Within One Year - Affiliated	131,000,000				131,000,000				0
Long-term Debt Due Within One Year	1,309,000,000				1,309,000,000				720,000,000
Long-term Debt - Affiliated	20,000,000				20,000,000				151,000,000
Long-term Debt	8,574,000,000				8,574,000,000				9,265,000,000
Total Long-term Debt Outstanding	10,034,000,000				10,034,000,000				10,136,000,000
Vertically Integrated Utilities [Member] | Significant Reconciling Items [Member]
Reportable Segment Information
Sales Revenue, Net	18,000,000	[3]	195,000,000		71,000,000	[3]	480,000,000
Transmission And Distribution Companies [Member]
Reportable Segment Information
Sales Revenue, Net	1,163,000,000		1,139,000,000		3,388,000,000		3,248,000,000
Revenues	1,231,000,000		1,195,000,000		3,580,000,000		3,393,000,000
NET INCOME (LOSS)	92,000,000		119,000,000		279,000,000		281,000,000
Balance Sheet Information
Total Property, Plant and Equipment	12,792,000,000				12,792,000,000				12,143,000,000
Accumulated Depreciation and Amortization	3,447,000,000				3,447,000,000				3,342,000,000
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	9,345,000,000				9,345,000,000				8,801,000,000
Total Assets	13,822,000,000				13,822,000,000				14,165,000,000
Long-term Debt Due Within One Year - Affiliated	0				0				0
Long-term Debt Due Within One Year	405,000,000				405,000,000				697,000,000
Long-term Debt - Affiliated	0				0				0
Long-term Debt	5,189,000,000				5,189,000,000				5,360,000,000
Total Long-term Debt Outstanding	5,594,000,000				5,594,000,000				6,057,000,000
Transmission And Distribution Companies [Member] | Significant Reconciling Items [Member]
Reportable Segment Information
Sales Revenue, Net	68,000,000		56,000,000		192,000,000		145,000,000
AEP Transmission Holdco [Member]
Reportable Segment Information
Sales Revenue, Net	21,000,000		9,000,000		54,000,000		18,000,000
Revenues	55,000,000		26,000,000		140,000,000		53,000,000
NET INCOME (LOSS)	43,000,000		22,000,000		114,000,000		53,000,000
Balance Sheet Information
Total Property, Plant and Equipment	2,378,000,000				2,378,000,000				1,636,000,000
Accumulated Depreciation and Amortization	20,000,000				20,000,000				10,000,000
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	2,358,000,000				2,358,000,000				1,626,000,000
Total Assets	3,000,000,000				3,000,000,000				2,245,000,000
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	699,000,000				699,000,000				620,000,000
Total Long-term Debt Outstanding	699,000,000				699,000,000				620,000,000
AEP Transmission Holdco [Member] | Significant Reconciling Items [Member]
Reportable Segment Information
Sales Revenue, Net	34,000,000		17,000,000		86,000,000		35,000,000
Generation And Marketing [Member]
Reportable Segment Information
Sales Revenue, Net	538,000,000	[3]	359,000,000		1,932,000,000	[3]	915,000,000
Revenues	901,000,000		1,001,000,000		3,065,000,000		2,813,000,000
NET INCOME (LOSS)	117,000,000		112,000,000		378,000,000		188,000,000
Balance Sheet Information
Total Property, Plant and Equipment	8,363,000,000				8,363,000,000				8,277,000,000
Accumulated Depreciation and Amortization	3,563,000,000				3,563,000,000				3,409,000,000
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	4,800,000,000				4,800,000,000				4,868,000,000
Total Assets	6,280,000,000				6,280,000,000				6,426,000,000
Long-term Debt Due Within One Year - Affiliated	86,000,000				86,000,000				179,000,000
Long-term Debt Due Within One Year	661,000,000				661,000,000				126,000,000
Long-term Debt - Affiliated	32,000,000				32,000,000				118,000,000
Long-term Debt	297,000,000				297,000,000				664,000,000
Total Long-term Debt Outstanding	1,076,000,000				1,076,000,000				1,087,000,000
Generation And Marketing [Member] | Significant Reconciling Items [Member]
Reportable Segment Information
Sales Revenue, Net	363,000,000	[3]	642,000,000		1,133,000,000	[3]	1,898,000,000
AEP River Operations [Member]
Reportable Segment Information
Sales Revenue, Net	141,000,000		126,000,000		435,000,000		365,000,000
Revenues	155,000,000		130,000,000		480,000,000		380,000,000
NET INCOME (LOSS)	11,000,000		(1,000,000)		17,000,000		(12,000,000)
Balance Sheet Information
Total Property, Plant and Equipment	673,000,000				673,000,000				638,000,000
Accumulated Depreciation and Amortization	212,000,000				212,000,000				189,000,000
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	461,000,000				461,000,000				449,000,000
Total Assets	686,000,000				686,000,000				673,000,000
Long-term Debt Due Within One Year - Affiliated	0				0				5,000,000
Long-term Debt Due Within One Year	3,000,000				3,000,000				2,000,000
Long-term Debt - Affiliated	0				0				10,000,000
Long-term Debt	81,000,000				81,000,000				83,000,000
Total Long-term Debt Outstanding	84,000,000				84,000,000				100,000,000
AEP River Operations [Member] | Significant Reconciling Items [Member]
Reportable Segment Information
Sales Revenue, Net	14,000,000		4,000,000		45,000,000		15,000,000
All Other [Member]
Reportable Segment Information
Sales Revenue, Net	7,000,000	[4]	12,000,000	[4]	19,000,000	[4]	26,000,000	[4]
Revenues	26,000,000	[4]	28,000,000	[4]	74,000,000	[4]	67,000,000	[4]
NET INCOME (LOSS)	11,000,000	[4]	8,000,000	[4]	4,000,000	[4]	119,000,000	[4]
Balance Sheet Information
Total Property, Plant and Equipment	331,000,000	[4]			331,000,000	[4]			315,000,000	[4]
Accumulated Depreciation and Amortization	183,000,000	[4]			183,000,000	[4]			173,000,000	[4]
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	148,000,000	[4]			148,000,000	[4]			142,000,000	[4]
Total Assets	20,706,000,000	[4]			20,706,000,000	[4]			19,645,000,000	[4]
Long-term Debt Due Within One Year - Affiliated	0	[4]			0	[4]			0	[4]
Long-term Debt Due Within One Year	3,000,000	[4]			3,000,000	[4]			4,000,000	[4]
Long-term Debt - Affiliated	0	[4]			0	[4]			0	[4]
Long-term Debt	837,000,000	[4]			837,000,000	[4]			836,000,000	[4]
Total Long-term Debt Outstanding	840,000,000	[4]			840,000,000	[4]			840,000,000	[4]
All Other [Member] | Significant Reconciling Items [Member]
Reportable Segment Information
Sales Revenue, Net	19,000,000	[4]	16,000,000	[4]	55,000,000	[4]	41,000,000	[4]
Consolidation, Eliminations [Member]
Reportable Segment Information
Sales Revenue, Net	0	[5]	(12,000,000)	[5]	(51,000,000)	[5]	(63,000,000)	[5]
Revenues	(516,000,000)		(942,000,000)		(1,633,000,000)		(2,677,000,000)
Consolidation, Eliminations [Member] | Reconciling Adjustments [Member]
Reportable Segment Information
Sales Revenue, Net	$ (516,000,000)		$ (930,000,000)		$ (1,582,000,000)		$ (2,614,000,000)

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

[2] 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.

[3] Includes the impact of the 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.

[4] 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.

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