Benefit Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Pension Plans [Member]
Components of Net Periodic Benefit Cost
Service Cost	$ 18,000	$ 17,000
Interest Cost	55,000	50,000
Expected Return on Plan Assets	(66,000)	(69,000)
Amortization of Prior Service Cost (Credit)	1,000	1,000
Amortization of Net Actuarial Loss	31,000	46,000
Net Periodic Benefit Cost (Credit)	39,000	45,000
Pension Plans [Member] | Appalachian Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	1,759	1,543
Interest Cost	7,406	6,916
Expected Return on Plan Assets	(8,482)	(9,260)
Amortization of Prior Service Cost (Credit)	50	49
Amortization of Net Actuarial Loss	4,148	6,256
Net Periodic Benefit Cost (Credit)	4,881	5,504
Pension Plans [Member] | Indiana Michigan Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	2,517	2,184
Interest Cost	6,573	6,025
Expected Return on Plan Assets	(7,748)	(8,207)
Amortization of Prior Service Cost (Credit)	49	49
Amortization of Net Actuarial Loss	3,646	5,422
Net Periodic Benefit Cost (Credit)	5,037	5,473
Pension Plans [Member] | Ohio Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	1,285	2,372
Interest Cost	5,526	10,292
Expected Return on Plan Assets	(6,607)	(15,141)
Amortization of Prior Service Cost (Credit)	39	71
Amortization of Net Actuarial Loss	3,106	9,309
Net Periodic Benefit Cost (Credit)	3,349	6,903
Pension Plans [Member] | Public Service Co Of Oklahoma [Member]
Components of Net Periodic Benefit Cost
Service Cost	1,302	1,391
Interest Cost	3,014	2,748
Expected Return on Plan Assets	(3,651)	(3,918)
Amortization of Prior Service Cost (Credit)	74	74
Amortization of Net Actuarial Loss	1,688	2,461
Net Periodic Benefit Cost (Credit)	2,427	2,756
Pension Plans [Member] | Southwestern Electric Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	1,655	1,753
Interest Cost	3,163	2,864
Expected Return on Plan Assets	(3,857)	(4,127)
Amortization of Prior Service Cost (Credit)	87	87
Amortization of Net Actuarial Loss	1,761	2,553
Net Periodic Benefit Cost (Credit)	2,809	3,130
Other Postretirement Benefit Plans [Member]
Components of Net Periodic Benefit Cost
Service Cost	4,000	6,000
Interest Cost	17,000	18,000
Expected Return on Plan Assets	(28,000)	(27,000)
Amortization of Prior Service Cost (Credit)	(17,000)	(17,000)
Amortization of Net Actuarial Loss	5,000	16,000
Net Periodic Benefit Cost (Credit)	(19,000)	(4,000)
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	362	641
Interest Cost	3,197	3,363
Expected Return on Plan Assets	(4,633)	(4,536)
Amortization of Prior Service Cost (Credit)	(2,513)	(2,512)
Amortization of Net Actuarial Loss	1,146	3,062
Net Periodic Benefit Cost (Credit)	(2,441)	18
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	487	805
Interest Cost	1,909	2,055
Expected Return on Plan Assets	(3,364)	(3,296)
Amortization of Prior Service Cost (Credit)	(2,355)	(2,355)
Amortization of Net Actuarial Loss	592	1,882
Net Periodic Benefit Cost (Credit)	(2,731)	(909)
Other Postretirement Benefit Plans [Member] | Ohio Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	256	1,300
Interest Cost	1,901	4,447
Expected Return on Plan Assets	(3,380)	(6,238)
Amortization of Prior Service Cost (Credit)	(1,731)	(3,231)
Amortization of Net Actuarial Loss	595	4,041
Net Periodic Benefit Cost (Credit)	(2,359)	319
Other Postretirement Benefit Plans [Member] | Public Service Co Of Oklahoma [Member]
Components of Net Periodic Benefit Cost
Service Cost	210	343
Interest Cost	893	948
Expected Return on Plan Assets	(1,575)	(1,522)
Amortization of Prior Service Cost (Credit)	(1,072)	(1,072)
Amortization of Net Actuarial Loss	277	869
Net Periodic Benefit Cost (Credit)	(1,267)	(434)
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	253	423
Interest Cost	998	1,075
Expected Return on Plan Assets	(1,754)	(1,720)
Amortization of Prior Service Cost (Credit)	(1,289)	(1,288)
Amortization of Net Actuarial Loss	309	982
Net Periodic Benefit Cost (Credit)	$ (1,483)	$ (528)