Condensed Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Appalachian Power Co [Member]	Indiana Michigan Power Co [Member]	Ohio Power Co [Member]	Public Service Co Of Oklahoma [Member]	Southwestern Electric Power Co [Member]	Common Stock [Member]	Common Stock [Member] Appalachian Power Co [Member]	Common Stock [Member] Indiana Michigan Power Co [Member]	Common Stock [Member] Ohio Power Co [Member]	Common Stock [Member] Public Service Co Of Oklahoma [Member]	Common Stock [Member] Southwestern Electric Power Co [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Appalachian Power Co [Member]	Additional Paid-in Capital [Member] Indiana Michigan Power Co [Member]	Additional Paid-in Capital [Member] Ohio Power Co [Member]	Additional Paid-in Capital [Member] Public Service Co Of Oklahoma [Member]	Additional Paid-in Capital [Member] Southwestern Electric Power Co [Member]	Retained Earnings [Member]	Retained Earnings [Member] Appalachian Power Co [Member]	Retained Earnings [Member] Indiana Michigan Power Co [Member]	Retained Earnings [Member] Ohio Power Co [Member]	Retained Earnings [Member] Public Service Co Of Oklahoma [Member]	Retained Earnings [Member] Southwestern Electric Power Co [Member]	Accumulated Other Comprehensive Income [Member]	Accumulated Other Comprehensive Income [Member] Appalachian Power Co [Member]	Accumulated Other Comprehensive Income [Member] Indiana Michigan Power Co [Member]	Accumulated Other Comprehensive Income [Member] Ohio Power Co [Member]	Accumulated Other Comprehensive Income [Member] Public Service Co Of Oklahoma [Member]	Accumulated Other Comprehensive Income [Member] Southwestern Electric Power Co [Member]	Noncontrolling Interests [Member]	Noncontrolling Interests [Member] Southwestern Electric Power Co [Member]
Beginning Balance at Dec. 31, 2013	$ 16,086,000	$ 3,229,432	$ 1,922,153	$ 1,625,265	$ 942,101	$ 2,055,917	$ 3,303,000	$ 260,458	$ 56,584	$ 321,201	$ 157,230	$ 135,660	$ 6,131,000	$ 1,809,562	$ 980,896	$ 663,782	$ 364,037	$ 674,606	$ 6,766,000	$ 1,156,461	$ 900,182	$ 633,203	$ 415,076	$ 1,253,617	$ (115,000)	$ 2,951	$ (15,509)	$ 7,079	$ 5,758	$ (8,444)	$ 1,000	$ 478
Beginning Balance, Shares at Dec. 31, 2013							508,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock, Value	29,000						$ 5,000						24,000
Issuance of Common Stock, Shares							1,000,000
Common Stock Dividends	(490,000)																		(488,000)
Common Stock Dividends		(40,000)	(75,000)	(35,000)		(50,000)														(40,000)	(75,000)	(35,000)		(50,000)
Common Stock Dividends						(2,309)																									(2,000)	(2,309)
Other Changes in Equity	(3,000)																		(6,000)												3,000
Net Income (Loss)																			950,000					53,557
Net Income (Loss) Attributable to Noncontrolling Interests	2,000					2,228																									2,000	2,228
Net Income (Loss)	952,000	138,098	114,423	117,309	30,897	55,785														138,098	114,423	117,309	30,897
Other Comprehensive Income (Loss)	11,000	(254)	861	(791)	(436)	600																			11,000	(254)	861	(791)	(436)	600
Ending Balance at Jun. 30, 2014	16,585,000	3,327,276	1,962,437	1,706,783	972,562	2,059,993	$ 3,308,000	260,458	56,584	321,201	157,230	135,660	6,155,000	1,809,562	980,896	663,782	364,037	674,606	7,222,000	1,254,559	939,605	715,512	445,973	1,257,174	(104,000)	2,697	(14,648)	6,288	5,322	(7,844)	4,000	397
Ending Balance, Shares at Jun. 30, 2014							509,000,000
Beginning Balance at Dec. 31, 2014	$ 16,824,000	3,366,928	1,953,949	1,980,210	$ 1,028,215	2,097,201	$ 3,313,000	260,458	56,584	321,201	157,230	135,660	6,204,000	1,809,562	980,896	838,782	364,037	674,606	7,406,000	1,291,876	930,829	814,625	502,005	1,293,986	(103,000)	5,032	(14,360)	5,602	4,943	(7,466)	4,000	415
Beginning Balance, Shares at Dec. 31, 2014	509,739,159				10,482,000		510,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock, Value	$ 56,000						$ 8,000						48,000
Issuance of Common Stock, Shares							1,000,000
Common Stock Dividends	(522,000)																		(520,000)
Common Stock Dividends		(118,750)	(60,000)	(87,500)		(60,000)														(118,750)	(60,000)	(87,500)		(60,000)
Common Stock Dividends						(2,107)																									(2,000)	(2,107)
Other Changes in Equity	4,000												1,000																		3,000
Deferred State Income Tax Rate Adjustment	17,000												17,000
Net Income (Loss)																			1,059,000					104,174
Net Income (Loss) Attributable to Noncontrolling Interests	3,000					1,989																									3,000	1,989
Net Income (Loss)	1,062,000	200,845	123,255	113,119	$ 40,783	106,163														200,845	123,255	113,119	40,783
Other Comprehensive Income (Loss)	(4,000)	(785)	557	(686)	(380)	655																			(4,000)	(785)	557	(686)	(380)	655
Ending Balance at Jun. 30, 2015	$ 17,442,000	$ 3,448,238	$ 2,017,761	$ 2,005,143	$ 1,068,618	$ 2,141,912	$ 3,321,000	$ 260,458	$ 56,584	$ 321,201	$ 157,230	$ 135,660	$ 6,270,000	$ 1,809,562	$ 980,896	$ 838,782	$ 364,037	$ 674,606	$ 7,945,000	$ 1,373,971	$ 994,084	$ 840,244	$ 542,788	$ 1,338,160	(102,000)	$ 4,247	$ (13,803)	$ 4,916	$ 4,563	$ (6,811)	$ 8,000	$ 297
Ending Balance, Shares at Jun. 30, 2015	510,884,774				10,482,000		511,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Pension and OPEB Adjustment Related to Mitchell Plant	$ 5,000																								$ 5,000