Benefit Plans (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
Pension Plans [Member]
Components of Net Periodic Benefit Cost
Service Cost	$ 17,000	$ 19,000	$ 52,000	$ 57,000
Interest Cost	51,000	56,000	152,000	167,000
Expected Return on Plan Assets	(69,000)	(80,000)	(208,000)	(239,000)
Amortization of Transition Obligation	0	0	0	0
Amortization of Prior Service Cost (Credit)	1,000	0	2,000	0
Amortization of Net Actuarial Loss	45,000	42,000	137,000	117,000
Net Periodic Benefit Cost (Credit)	45,000	37,000	135,000	102,000
Pension Plans [Member] | Appalachian Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	1,543	1,892	4,628	5,674
Interest Cost	6,916	7,553	20,747	22,659
Expected Return on Plan Assets	(9,260)	(10,486)	(27,780)	(31,458)
Amortization of Transition Obligation	0	0	0	0
Amortization of Prior Service Cost (Credit)	49	118	148	356
Amortization of Net Actuarial Loss	6,256	5,085	18,769	15,254
Net Periodic Benefit Cost (Credit)	5,504	4,162	16,512	12,485
Pension Plans [Member] | Indiana Michigan Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	2,183	2,477	6,551	7,431
Interest Cost	6,025	6,562	18,075	19,684
Expected Return on Plan Assets	(8,206)	(9,392)	(24,619)	(28,175)
Amortization of Transition Obligation	0	0	0	0
Amortization of Prior Service Cost (Credit)	49	101	146	305
Amortization of Net Actuarial Loss	5,422	4,392	16,266	13,177
Net Periodic Benefit Cost (Credit)	5,473	4,140	16,419	12,422
Pension Plans [Member] | Ohio Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	2,362	2,751	7,107	8,253
Interest Cost	10,268	11,298	30,852	33,895
Expected Return on Plan Assets	(15,103)	(17,100)	(45,386)	(51,301)
Amortization of Transition Obligation	0	0	0	0
Amortization of Prior Service Cost (Credit)	71	186	212	557
Amortization of Net Actuarial Loss	9,287	7,610	27,905	22,830
Net Periodic Benefit Cost (Credit)	6,885	4,745	20,690	14,234
Pension Plans [Member] | Public Service Co Of Oklahoma [Member]
Components of Net Periodic Benefit Cost
Service Cost	1,391	1,487	4,172	4,463
Interest Cost	2,748	3,076	8,245	9,226
Expected Return on Plan Assets	(3,919)	(4,503)	(11,756)	(13,511)
Amortization of Prior Service Cost (Credit)	75	(237)	223	(711)
Amortization of Net Actuarial Loss	2,461	2,051	7,383	6,154
Net Periodic Benefit Cost (Credit)	2,756	1,874	8,267	5,621
Pension Plans [Member] | Southwestern Electric Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	1,752	1,775	5,258	5,324
Interest Cost	2,864	3,134	8,591	9,403
Expected Return on Plan Assets	(4,126)	(4,717)	(12,381)	(14,150)
Amortization of Prior Service Cost (Credit)	87	(198)	262	(595)
Amortization of Net Actuarial Loss	2,553	2,083	7,660	6,248
Net Periodic Benefit Cost (Credit)	3,130	2,077	9,390	6,230
Other Postretirement Benefit Plans [Member]
Components of Net Periodic Benefit Cost
Service Cost	5,000	12,000	17,000	35,000
Interest Cost	18,000	26,000	53,000	78,000
Expected Return on Plan Assets	(27,000)	(26,000)	(80,000)	(76,000)
Amortization of Transition Obligation	0	1,000	0	1,000
Amortization of Prior Service Cost (Credit)	(17,000)	(5,000)	(52,000)	(14,000)
Amortization of Net Actuarial Loss	16,000	14,000	48,000	43,000
Net Periodic Benefit Cost (Credit)	(5,000)	22,000	(14,000)	67,000
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	641	1,346	1,924	4,040
Interest Cost	3,363	4,616	10,090	13,847
Expected Return on Plan Assets	(4,537)	(4,188)	(13,610)	(12,564)
Amortization of Transition Obligation	0	201	0	601
Amortization of Prior Service Cost (Credit)	(2,512)	(716)	(7,537)	(2,147)
Amortization of Net Actuarial Loss	3,063	2,631	9,187	7,894
Net Periodic Benefit Cost (Credit)	18	3,890	54	11,671
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	804	1,655	2,414	4,965
Interest Cost	2,056	3,196	6,166	9,589
Expected Return on Plan Assets	(3,295)	(3,212)	(9,887)	(9,635)
Amortization of Transition Obligation	0	33	0	99
Amortization of Prior Service Cost (Credit)	(2,356)	(595)	(7,066)	(1,787)
Amortization of Net Actuarial Loss	1,882	1,762	5,645	5,287
Net Periodic Benefit Cost (Credit)	(909)	2,839	(2,728)	8,518
Other Postretirement Benefit Plans [Member] | Ohio Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	1,028	2,187	3,627	6,561
Interest Cost	4,100	6,047	12,994	18,142
Expected Return on Plan Assets	(6,221)	(5,639)	(18,698)	(16,917)
Amortization of Transition Obligation	0	26	0	78
Amortization of Prior Service Cost (Credit)	(3,219)	(969)	(9,680)	(2,905)
Amortization of Net Actuarial Loss	3,761	3,418	11,843	10,252
Net Periodic Benefit Cost (Credit)	(551)	5,070	86	15,211
Other Postretirement Benefit Plans [Member] | Public Service Co Of Oklahoma [Member]
Components of Net Periodic Benefit Cost
Service Cost	343	709	1,029	2,127
Interest Cost	948	1,449	2,844	4,348
Expected Return on Plan Assets	(1,522)	(1,480)	(4,566)	(4,441)
Amortization of Prior Service Cost (Credit)	(1,072)	(270)	(3,217)	(809)
Amortization of Net Actuarial Loss	869	797	2,607	2,391
Net Periodic Benefit Cost (Credit)	(434)	1,205	(1,303)	3,616
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	424	831	1,270	2,493
Interest Cost	1,075	1,669	3,226	5,005
Expected Return on Plan Assets	(1,720)	(1,699)	(5,160)	(5,096)
Amortization of Prior Service Cost (Credit)	(1,289)	(234)	(3,867)	(700)
Amortization of Net Actuarial Loss	982	915	2,946	2,744
Net Periodic Benefit Cost (Credit)	$ (528)	$ 1,482	$ (1,585)	$ 4,446