Benefit Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Pension Plans [Member]
Components of Net Periodic Benefit Cost
Service Cost	$ 17,000	$ 19,000
Interest Cost	50,000	56,000
Expected Return on Plan Assets	(69,000)	(80,000)
Amortization of Prior Service Cost (Credit)	1,000	0
Amortization of Net Actuarial Loss	46,000	37,000
Net Periodic Benefit Cost	45,000	32,000
Pension Plans [Member] | Appalachian Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	1,543	1,891
Interest Cost	6,916	7,553
Expected Return on Plan Assets	(9,260)	(10,486)
Amortization of Transition Obligation	0	0
Amortization of Prior Service Cost (Credit)	49	119
Amortization of Net Actuarial Loss	6,256	5,085
Net Periodic Benefit Cost	5,504	4,162
Pension Plans [Member] | Indiana Michigan Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	2,184	2,477
Interest Cost	6,025	6,561
Expected Return on Plan Assets	(8,207)	(9,391)
Amortization of Transition Obligation	0	0
Amortization of Prior Service Cost (Credit)	49	102
Amortization of Net Actuarial Loss	5,422	4,392
Net Periodic Benefit Cost	5,473	4,141
Pension Plans [Member] | Ohio Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	2,372	2,751
Interest Cost	10,292	11,298
Expected Return on Plan Assets	(15,141)	(17,100)
Amortization of Transition Obligation	0	0
Amortization of Prior Service Cost (Credit)	71	186
Amortization of Net Actuarial Loss	9,309	7,610
Net Periodic Benefit Cost	6,903	4,745
Pension Plans [Member] | Public Service Co Of Oklahoma [Member]
Components of Net Periodic Benefit Cost
Service Cost	1,391	1,488
Interest Cost	2,748	3,075
Expected Return on Plan Assets	(3,918)	(4,504)
Amortization of Prior Service Cost (Credit)	74	(237)
Amortization of Net Actuarial Loss	2,461	2,052
Net Periodic Benefit Cost	2,756	1,874
Pension Plans [Member] | Southwestern Electric Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	1,753	1,775
Interest Cost	2,864	3,134
Expected Return on Plan Assets	(4,127)	(4,717)
Amortization of Prior Service Cost (Credit)	87	(198)
Amortization of Net Actuarial Loss	2,553	2,083
Net Periodic Benefit Cost	3,130	2,077
Other Postretirement Benefit Plans [Member]
Components of Net Periodic Benefit Cost
Service Cost	6,000	12,000
Interest Cost	18,000	26,000
Expected Return on Plan Assets	(27,000)	(25,000)
Amortization of Prior Service Cost (Credit)	(17,000)	(5,000)
Amortization of Net Actuarial Loss	16,000	14,000
Net Periodic Benefit Cost	(4,000)	22,000
Other Postretirement Benefit Plans [Member] | Appalachian Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	641	1,347
Interest Cost	3,363	4,616
Expected Return on Plan Assets	(4,536)	(4,188)
Amortization of Transition Obligation	0	200
Amortization of Prior Service Cost (Credit)	(2,512)	(716)
Amortization of Net Actuarial Loss	3,062	2,631
Net Periodic Benefit Cost	18	3,890
Other Postretirement Benefit Plans [Member] | Indiana Michigan Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	805	1,655
Interest Cost	2,055	3,196
Expected Return on Plan Assets	(3,296)	(3,211)
Amortization of Transition Obligation	0	33
Amortization of Prior Service Cost (Credit)	(2,355)	(596)
Amortization of Net Actuarial Loss	1,882	1,762
Net Periodic Benefit Cost	(909)	2,839
Other Postretirement Benefit Plans [Member] | Ohio Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	1,300	2,187
Interest Cost	4,447	6,047
Expected Return on Plan Assets	(6,238)	(5,639)
Amortization of Transition Obligation	0	26
Amortization of Prior Service Cost (Credit)	(3,231)	(968)
Amortization of Net Actuarial Loss	4,041	3,417
Net Periodic Benefit Cost	319	5,070
Other Postretirement Benefit Plans [Member] | Public Service Co Of Oklahoma [Member]
Components of Net Periodic Benefit Cost
Service Cost	343	709
Interest Cost	948	1,449
Expected Return on Plan Assets	(1,522)	(1,480)
Amortization of Prior Service Cost (Credit)	(1,072)	(270)
Amortization of Net Actuarial Loss	869	797
Net Periodic Benefit Cost	(434)	1,205
Other Postretirement Benefit Plans [Member] | Southwestern Electric Power Co [Member]
Components of Net Periodic Benefit Cost
Service Cost	423	831
Interest Cost	1,075	1,668
Expected Return on Plan Assets	(1,720)	(1,699)
Amortization of Prior Service Cost (Credit)	(1,288)	(233)
Amortization of Net Actuarial Loss	982	915
Net Periodic Benefit Cost	$ (528)	$ 1,482