Business Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012		Dec. 31, 2012
Reportable Segment Information
Revenues	$ 4,176,000		$ 4,156,000		$ 11,584,000		$ 11,332,000
NET INCOME (LOSS)	434,000		488,000		1,137,000		1,241,000
Balance Sheet Information
Total Property, Plant and Equipment	59,044,000				59,044,000				57,454,000
Accumulated Depreciation and Amortization	19,174,000				19,174,000				18,691,000
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	39,870,000				39,870,000				38,763,000
Total Assets	54,963,000				54,963,000				54,367,000
Reconciling Adjustments [Member]
Reportable Segment Information
Revenues	(57,000)		(44,000)		(150,000)		(108,000)
NET INCOME (LOSS)	0		0		0		0
Balance Sheet Information
Total Property, Plant and Equipment	(269,000)	[1]			(269,000)	[1]			(266,000)	[1]
Accumulated Depreciation and Amortization	(82,000)	[1]			(82,000)	[1]			(71,000)	[1]
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	(187,000)	[1]			(187,000)	[1]			(195,000)	[1]
Total Assets	(17,977,000)	[1],[2]			(17,977,000)	[1],[2]			(17,192,000)	[1],[2]
Utility Operations [Member]
Reportable Segment Information
Revenues	3,788,000		3,811,000		10,520,000		10,407,000
NET INCOME (LOSS)	409,000		471,000		980,000		1,220,000
Balance Sheet Information
Total Property, Plant and Equipment	56,745,000				56,745,000				55,707,000
Accumulated Depreciation and Amortization	18,791,000				18,791,000				18,344,000
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	37,954,000				37,954,000				37,363,000
Total Assets	51,598,000				51,598,000				51,477,000
Utility Operations [Member] | Operating Segments [Member]
Reportable Segment Information
Revenues	3,819,000		3,839,000		10,614,000		10,482,000
Utility Operations [Member] | Significant Reconciling Items [Member]
Reportable Segment Information
Revenues	31,000		28,000		94,000		75,000
Transmission Operations [Member]
Reportable Segment Information
Revenues	8,000		3,000		18,000		5,000
NET INCOME (LOSS)	22,000		14,000		53,000		31,000
Balance Sheet Information
Total Property, Plant and Equipment	1,296,000				1,296,000				748,000
Accumulated Depreciation and Amortization	7,000				7,000				4,000
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	1,289,000				1,289,000				744,000
Total Assets	1,809,000				1,809,000				1,216,000
Transmission Operations [Member] | Operating Segments [Member]
Reportable Segment Information
Revenues	26,000		10,000		53,000		15,000
Transmission Operations [Member] | Significant Reconciling Items [Member]
Reportable Segment Information
Revenues	18,000		7,000		35,000		10,000
Nonutility Operations - AEP River Operations [Member]
Reportable Segment Information
Revenues	125,000		142,000		365,000		477,000
NET INCOME (LOSS)	(1,000)		(1,000)		(12,000)		11,000
Balance Sheet Information
Total Property, Plant and Equipment	637,000				637,000				636,000
Accumulated Depreciation and Amortization	182,000				182,000				161,000
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	455,000				455,000				475,000
Total Assets	650,000				650,000				670,000
Nonutility Operations - AEP River Operations [Member] | Operating Segments [Member]
Reportable Segment Information
Revenues	130,000		147,000		380,000		493,000
Nonutility Operations - AEP River Operations [Member] | Significant Reconciling Items [Member]
Reportable Segment Information
Revenues	5,000		5,000		15,000		16,000
Nonutility Operations - Generation and Marketing [Member]
Reportable Segment Information
Revenues	251,000		194,000		671,000		427,000
NET INCOME (LOSS)	4,000		10,000		15,000		4,000
Balance Sheet Information
Total Property, Plant and Equipment	627,000				627,000				621,000
Accumulated Depreciation and Amortization	268,000				268,000				246,000
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	359,000				359,000				375,000
Total Assets	1,009,000				1,009,000				1,005,000
Nonutility Operations - Generation and Marketing [Member] | Operating Segments [Member]
Reportable Segment Information
Revenues	251,000		194,000		671,000		427,000
Nonutility Operations - Generation and Marketing [Member] | Significant Reconciling Items [Member]
Reportable Segment Information
Revenues	0		0		0		0
All Other [Member]
Reportable Segment Information
Revenues	4,000	[3]	6,000	[3]	10,000	[3]	16,000	[3]
NET INCOME (LOSS)	0	[3]	(6,000)	[3]	101,000	[3]	(25,000)	[3]
Balance Sheet Information
Total Property, Plant and Equipment	8,000	[3]			8,000	[3]			8,000	[3]
Accumulated Depreciation and Amortization	8,000	[3]			8,000	[3]			7,000	[3]
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET	0	[3]			0	[3]			1,000	[3]
Total Assets	17,874,000	[3]			17,874,000	[3]			17,191,000	[3]
All Other [Member] | Operating Segments [Member]
Reportable Segment Information
Revenues	7,000	[3]	10,000	[3]	16,000	[3]	23,000	[3]
All Other [Member] | Significant Reconciling Items [Member]
Reportable Segment Information
Revenues	$ 3,000	[3]	$ 4,000	[3]	$ 6,000	[3]	$ 7,000	[3]

[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] All Other includes Parent's guarantee revenue received from affiliates, investment income, interest income and interest expense and other nonallocated costs.