Fair Value Assets and Liabilities (Details) $ in Thousands		3 Months Ended			9 Months Ended			12 Months Ended
		Sep. 30, 2015 USD ($) $ / MWh		Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) $ / MWh		Sep. 30, 2014 USD ($)	Dec. 31, 2014 USD ($) $ / MWh
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents	[1]	$ 178,000			$ 178,000			$ 163,000
Other Temporary Investments		315,000			315,000			386,000
Risk Management Assets
Risk Management Assets		496,000			496,000			472,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		2,047,000			2,047,000			2,096,000
Total Assets		3,036,000			3,036,000			3,117,000
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		276,000			276,000			223,000
Changes in the Fair Value of Net Trading Derivatives and other investments
Beginning Balance		203,000		$ 132,000	151,000		$ 117,000	117,000
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	[2],[3]	11,000		(9,000)	14,000		91,000
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	[2]	6,000		10,000	54,000		(3,000)
Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income		(2,000)		(3,000)	(4,000)		12,000
Purchases, Issuances and Settlements	[4]	(29,000)		(5,000)	(60,000)		(103,000)
Transfers into Level 3	[5],[6]	8,000		(9,000)	28,000		(9,000)
Transfers out of Level 3	[6],[7]	(5,000)		(1,000)	(17,000)		(8,000)
Changes in Fair Value Allocated to Regulated Jurisdictions	[8]	(25,000)		14,000	1,000		32,000
Ending Balance		167,000		129,000	$ 167,000		129,000	$ 151,000
Level 3 Quantitative Information [Abstract]
Counterparty Credit Risk	[9]				4.81%			3.03%
Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents	[1]	12,000			$ 12,000			$ 17,000
Other Temporary Investments		303,000			303,000			340,000
Risk Management Assets
Risk Management Assets		17,000			17,000			37,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,224,000			1,224,000			1,132,000
Total Assets		1,556,000			1,556,000			1,526,000
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		33,000			33,000			65,000
Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents	[1]	4,000			4,000			1,000
Other Temporary Investments		6,000			6,000			9,000
Risk Management Assets
Risk Management Assets		489,000			489,000			561,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		816,000			816,000			953,000
Total Assets		1,315,000			1,315,000			1,524,000
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		463,000			463,000			467,000
Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents	[1]	0			0			0
Other Temporary Investments		0			0			0
Risk Management Assets
Risk Management Assets		249,000			249,000			190,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
Total Assets		249,000			249,000			190,000
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		82,000			82,000			39,000
Fair Value Inputs Other [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents	[1]	162,000			162,000			145,000
Other Temporary Investments		6,000			6,000			37,000
Risk Management Assets
Risk Management Assets		(259,000)			(259,000)			(316,000)
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		7,000			7,000			11,000
Total Assets		(84,000)			(84,000)			(123,000)
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		(302,000)			(302,000)			(348,000)
2015 [Member] | Level 1 [Member]
Fair Value Measurements 1 (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		(4,000)			(4,000)			(18,000)
2015 [Member] | Level 2 [Member]
Fair Value Measurements 1 (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		5,000			5,000			31,000
2015 [Member] | Level 3 [Member]
Fair Value Measurements 1 (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		2,000			2,000			50,000
2016 - 2018 [Member] | Level 1 [Member]
Fair Value Measurements 1 (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		(12,000)			(12,000)			(10,000)
2016 - 2018 [Member] | Level 2 [Member]
Fair Value Measurements 1 (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		28,000			28,000			52,000
2016 - 2018 [Member] | Level 3 [Member]
Fair Value Measurements 1 (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		63,000			63,000			29,000
2019 - 2020 [Member] | Level 2 [Member]
Fair Value Measurements 1 (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		3,000			3,000			12,000
2019 - 2020 [Member] | Level 3 [Member]
Fair Value Measurements 1 (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		25,000			25,000			9,000
2021 - 2030 [Member] | Level 2 [Member]
Fair Value Measurements 1 (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities								1,000
2021 - 2030 [Member] | Level 3 [Member]
Fair Value Measurements 1 (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities								66,000
2021 - 2032 [Member] | Level 2 [Member]
Fair Value Measurements 1 (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		2,000			2,000
2021 - 2032 [Member] | Level 3 [Member]
Fair Value Measurements 1 (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities		82,000			82,000
Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	[10]	487,000	[11]		487,000	[11]		453,000	[12]
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[10]	250,000	[11]		250,000	[11]		199,000	[12]
Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[10]	17,000	[11]		17,000	[11]		37,000	[12]
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[10]	33,000	[11]		33,000	[11]		65,000	[12]
Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[10]	478,000	[11]		478,000	[11]		528,000	[12]
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[10]	440,000	[11]		440,000	[11]		432,000	[12]
Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[10]	248,000	[11]		248,000	[11]		190,000	[12]
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[10]	76,000	[11]		76,000	[11]		36,000	[12]
Risk Management Commodity Contracts [Member] | Fair Value Inputs Other [Member]
Risk Management Assets
Risk Management Assets	[10]	(256,000)	[11]		(256,000)	[11]		(302,000)	[12]
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[10]	(299,000)	[11]		(299,000)	[11]		(334,000)	[12]
Energy Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		226,000			226,000			157,000
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		$ 79,000			$ 79,000			$ 37,000
Level 3 Quantitative Information [Abstract]
Forward Price Range Low | $ / MWh	[13]	13.03			13.03			11.37
Forward Price Range High | $ / MWh	[13]	165.93			165.93			159.92
Weighted Average Market Price | $ / MWh	[13]	36.37			36.37			57.18
FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		$ 23,000			$ 23,000			$ 33,000
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		$ 3,000			$ 3,000			$ 2,000
Level 3 Quantitative Information [Abstract]
Forward Price Range Low | $ / MWh	[13]	(10.67)			(10.67)			(14.63)
Forward Price Range High | $ / MWh	[13]	11.6			11.6			20.02
Weighted Average Market Price | $ / MWh	[13]	1.31			1.31			0.96
Commodity Hedges [Member]
Risk Management Assets
Risk Management Assets	[10]	$ 7,000			$ 7,000			$ 16,000
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[10]	24,000			24,000			14,000
Commodity Hedges [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[10]	0			0			0
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[10]	0			0			0
Commodity Hedges [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[10]	10,000			10,000			32,000
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[10]	22,000			22,000			27,000
Commodity Hedges [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[10]	1,000			1,000			0
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[10]	6,000			6,000			3,000
Commodity Hedges [Member] | Fair Value Inputs Other [Member]
Risk Management Assets
Risk Management Assets	[10]	(4,000)			(4,000)			(16,000)
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[10]	(4,000)			(4,000)			(16,000)
Interest Rate Foreign Currency Hedges [Member]
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		1,000			1,000			1,000
Interest Rate Foreign Currency Hedges [Member] | Level 1 [Member]
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		0			0			0
Interest Rate Foreign Currency Hedges [Member] | Level 2 [Member]
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		1,000			1,000			1,000
Interest Rate Foreign Currency Hedges [Member] | Level 3 [Member]
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		0			0			0
Interest Rate Foreign Currency Hedges [Member] | Fair Value Inputs Other [Member]
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		0			0			0
Fair Value Hedges [Member]
Risk Management Assets
Risk Management Assets		2,000			2,000			3,000
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		1,000			1,000			9,000
Fair Value Hedges [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets		0			0			0
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		0			0			0
Fair Value Hedges [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets		1,000			1,000			1,000
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		0			0			7,000
Fair Value Hedges [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		0			0			0
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		0			0			0
Fair Value Hedges [Member] | Fair Value Inputs Other [Member]
Risk Management Assets
Risk Management Assets		1,000			1,000			2,000
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		1,000			1,000			2,000
Appalachian Power Co [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents	[14]	7,493			7,493			15,632
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		36,878			36,878			44,315
Changes in the Fair Value of Net Trading Derivatives and other investments
Beginning Balance		33,836	[15]	18,394	15,742	[15]	10,562	10,562
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	[16],[17]	5,065	[15]	(5,629)	1,757	[15]	29,467
Purchases, Issuances and Settlements	[18]	(13,965)	[15]	(1,560)	(16,124)	[15]	(32,213)
Transfers into Level 3	[19],[20]			(6)			(3,648)
Transfers out of Level 3	[20],[21]			(30)	1,167	[15]	(32)
Changes in Fair Value Allocated to Regulated Jurisdictions	[22]	(1,855)	[15]	4,843	20,539	[15]	11,876
Ending Balance		23,081	[15]	16,012	23,081	[15]	16,012	15,742	[15]
Appalachian Power Co [Member] | Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents	[14]	7,436			7,436			15,599
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		7,621			7,621			15,805
Appalachian Power Co [Member] | Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents	[14]	0			0			0
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		12,785			12,785			20,197
Appalachian Power Co [Member] | Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents	[14]	0			0			0
Risk Management Assets
Risk Management Assets		23,743			23,743			17,654
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		23,743			23,743			17,654
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		662			662			1,912
Appalachian Power Co [Member] | Fair Value Inputs Other [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents	[14]	57			57			33
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		(7,271)			(7,271)			(9,341)
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	29,385			29,385			28,683
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	7,875			7,875			13,074
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	185			185			206
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	198			198			227
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	12,785			12,785			20,197
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	16,031			16,031			20,339
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	23,743			23,743			17,654
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	662			662			1,912
Appalachian Power Co [Member] | Risk Management Commodity Contracts [Member] | Fair Value Inputs Other [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	(7,328)			(7,328)			(9,374)
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	(9,016)			(9,016)			(9,404)
Appalachian Power Co [Member] | Energy Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		8,724			8,724			5,801
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		$ 451			$ 451			$ 1,799
Level 3 Quantitative Information [Abstract]
Forward Price Range Low | $ / MWh	[25]	13.03			13.03			13.43
Forward Price Range High | $ / MWh	[25]	48.17			48.17			123.02
Weighted Average Market Price | $ / MWh	[25]	34.76			34.76			52.47
Appalachian Power Co [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		$ 15,019			$ 15,019			$ 11,853
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		$ 211			$ 211			$ 113
Level 3 Quantitative Information [Abstract]
Forward Price Range Low | $ / MWh	[25]	(5.95)			(5.95)			(14.63)
Forward Price Range High | $ / MWh	[25]	11.6			11.6			20.02
Weighted Average Market Price | $ / MWh	[25]	1.53			1.53			1.01
Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		$ 2,047,260			$ 2,047,260			$ 2,095,732
Total Assets		2,059,225			2,059,225			2,121,377
Changes in the Fair Value of Net Trading Derivatives and other investments
Beginning Balance		11,844	[15]	12,923	14,704	[15]	7,164	7,164
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	[16],[17]	885	[15]	(3,832)	(193)	[15]	18,438
Purchases, Issuances and Settlements	[18]	(3,604)	[15]	(1,244)	(12,807)	[15]	(20,301)
Transfers into Level 3	[19],[20]			(4)			(2,475)
Transfers out of Level 3	[20],[21]			(20)	792	[15]	(22)
Changes in Fair Value Allocated to Regulated Jurisdictions	[22]	(2,749)	[15]	4,319	3,880	[15]	9,338
Ending Balance		6,376	[15]	12,142	6,376	[15]	12,142	14,704	[15]
Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		1,223,836			1,223,836			1,131,797
Total Assets		1,223,962			1,223,962			1,131,937
Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		816,480			816,480			953,387
Total Assets		826,827			826,827			969,280
Indiana Michigan Power Co [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		7,795			7,795			16,008
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
Total Assets		7,795			7,795			16,008
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		1,419			1,419			1,304
Indiana Michigan Power Co [Member] | Fair Value Inputs Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		6,944			6,944			10,548
Total Assets		641			641			4,152
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	11,965			11,965			25,645
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	5,863			5,863			6,618
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	126			126			140
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	135			135			154
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	10,347			10,347			15,893
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	10,945			10,945			11,440
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	7,795			7,795			16,008
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	1,419			1,419			1,304
Indiana Michigan Power Co [Member] | Risk Management Commodity Contracts [Member] | Fair Value Inputs Other [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	(6,303)			(6,303)			(6,396)
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	(6,636)			(6,636)			(6,280)
Indiana Michigan Power Co [Member] | Energy Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		7,147			7,147			6,375
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		$ 295			$ 295			$ 1,219
Level 3 Quantitative Information [Abstract]
Forward Price Range Low | $ / MWh	[25]	13.03			13.03			13.43
Forward Price Range High | $ / MWh	[25]	48.17			48.17			123.02
Weighted Average Market Price | $ / MWh	[25]	34.76			34.76			52.47
Indiana Michigan Power Co [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		$ 648			$ 648			$ 9,633
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		$ 1,124			$ 1,124			$ 85
Level 3 Quantitative Information [Abstract]
Forward Price Range Low | $ / MWh	[25]	(5.95)			(5.95)			(14.63)
Forward Price Range High | $ / MWh	[25]	11.6			11.6			20.02
Weighted Average Market Price | $ / MWh	[25]	1.53			1.53			1.01
Ohio Power Co [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents	[14]	$ 16,204			$ 16,204			$ 28,696
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		39,469			39,469			81,040
Changes in the Fair Value of Net Trading Derivatives and other investments
Beginning Balance		37,657		9,300	48,402		2,920	2,920
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	[16],[17]	(28)		(3,639)	1,182		30,768
Purchases, Issuances and Settlements	[18]	348		(637)	(7,906)		(33,688)
Transfers into Level 3	[19],[20]			0			0
Transfers out of Level 3	[20],[21]			0	0		0
Changes in Fair Value Allocated to Regulated Jurisdictions	[22]	(22,267)		2,865	(25,968)		7,889
Ending Balance		15,710		7,889	15,710		7,889	48,402
Ohio Power Co [Member] | Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents	[14]	16,195			16,195			408
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		16,195			16,195			408
Ohio Power Co [Member] | Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents	[14]	0			0			0
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		0			0			0
Ohio Power Co [Member] | Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents	[14]	0			0			0
Risk Management Assets
Risk Management Assets								52,343
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		20,719			20,719			52,343
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities								3,941
Ohio Power Co [Member] | Fair Value Inputs Other [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents	[14]	9			9			28,288
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		2,555			2,555			28,289
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	23,265			23,265			52,344
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	7,694			7,694			4,956
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	0			0			0
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	0			0			0
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	0			0			0
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	639			639			1,116
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	20,719			20,719			52,343
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	5,009			5,009			3,941
Ohio Power Co [Member] | Risk Management Commodity Contracts [Member] | Fair Value Inputs Other [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	2,546			2,546			1
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	2,046			2,046			(101)
Ohio Power Co [Member] | Energy Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		20,719			20,719			45,101
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		$ 5,009			$ 5,009			$ 3,941
Level 3 Quantitative Information [Abstract]
Forward Price Range Low | $ / MWh	[25]	35.71			35.71			48.25
Forward Price Range High | $ / MWh	[25]	165.93			165.93			159.92
Weighted Average Market Price | $ / MWh	[25]	85.99			85.99			84.04
Ohio Power Co [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets								$ 7,242
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities								$ 0
Level 3 Quantitative Information [Abstract]
Forward Price Range Low | $ / MWh	[25]							(14.63)
Forward Price Range High | $ / MWh	[25]							20.02
Weighted Average Market Price | $ / MWh	[25]							1.01
Public Service Co Of Oklahoma [Member]
Changes in the Fair Value of Net Trading Derivatives and other investments
Beginning Balance		$ 1,699		(3)	$ (377)		0	$ 0
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	[16],[17]	(280)		2	(176)		0
Purchases, Issuances and Settlements	[18]	(176)		0	553		0
Transfers into Level 3	[19],[20]			0			0
Transfers out of Level 3	[20],[21]			0	0		0
Changes in Fair Value Allocated to Regulated Jurisdictions	[22]	(208)		335	1,035		334
Ending Balance		1,035		334	1,035		334	(377)
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	1,035			1,035			0
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	78			78			918
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	0			0			0
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	0			0			0
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	0			0			0
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	358			358			595
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	1,166			1,166			360
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	131			131			737
Public Service Co Of Oklahoma [Member] | Risk Management Commodity Contracts [Member] | Fair Value Inputs Other [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	(131)			(131)			(360)
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	(411)			(411)			(414)
Public Service Co Of Oklahoma [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		1,166			1,166			360
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		$ 131			$ 131			$ 737
Level 3 Quantitative Information [Abstract]
Forward Price Range Low | $ / MWh	[25]	(5.95)			(5.95)			(14.63)
Forward Price Range High | $ / MWh	[25]	11.6			11.6			20.02
Weighted Average Market Price | $ / MWh	[25]	1.53			1.53			1.01
Southwestern Electric Power Co [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents	[14]	$ 14,258			$ 14,258			$ 14,356
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		15,538			15,538			14,387
Changes in the Fair Value of Net Trading Derivatives and other investments
Beginning Balance		2,039		(3)	(460)		0	0
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	[16],[17]	2,366		2	9,187		0
Purchases, Issuances and Settlements	[18]	(2,912)		0	(8,727)		0
Transfers into Level 3	[19],[20]			0			0
Transfers out of Level 3	[20],[21]			0	0		0
Changes in Fair Value Allocated to Regulated Jurisdictions	[22]	(213)		409	1,280		408
Ending Balance		1,280		$ 408	1,280		$ 408	(460)
Southwestern Electric Power Co [Member] | Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents	[14]	11,688			11,688			12,660
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		11,688			11,688			12,660
Southwestern Electric Power Co [Member] | Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents	[14]	0			0			0
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		0			0			31
Southwestern Electric Power Co [Member] | Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents	[14]	0			0			0
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		1,442			1,442			439
Southwestern Electric Power Co [Member] | Fair Value Inputs Other [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents	[14]	2,570			2,570			1,696
Spent Nuclear Fuel and Decommissioning Trusts
Total Assets		2,408			2,408			1,257
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	1,280			1,280			31
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	2,059			2,059			1,082
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	0			0			0
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	0			0			0
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	0			0			31
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	2,378			2,378			684
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	1,442			1,442			439
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	162			162			899
Southwestern Electric Power Co [Member] | Risk Management Commodity Contracts [Member] | Fair Value Inputs Other [Member]
Risk Management Assets
Risk Management Assets	[23],[24]	(162)			(162)			(439)
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities	[23],[24]	(481)			(481)			(501)
Southwestern Electric Power Co [Member] | FTRs [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets		1,442			1,442			439
Liabilities, Fair Value Disclosure [Abstract]
Risk Management Liabilities		$ 162			$ 162			$ 899
Level 3 Quantitative Information [Abstract]
Forward Price Range Low | $ / MWh	[25]	(5.95)			(5.95)			(14.63)
Forward Price Range High | $ / MWh	[25]	11.6			11.6			20.02
Weighted Average Market Price | $ / MWh	[25]	1.53			1.53			1.01
Cash [Member]
Assets, Fair Value Disclosure [Abstract]
Other Temporary Investments	[1],[26]	$ 201,000			$ 201,000			$ 280,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[27]	164,000			164,000			20,000
Cash [Member] | Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Other Temporary Investments	[1]	189,000			189,000			234,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[27]	157,000			157,000			9,000
Cash [Member] | Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Other Temporary Investments	[1]	6,000			6,000			9,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[27]	0			0			0
Cash [Member] | Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Other Temporary Investments	[1]	0			0			0
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[27]	0			0			0
Cash [Member] | Fair Value Inputs Other [Member]
Assets, Fair Value Disclosure [Abstract]
Other Temporary Investments	[1]	6,000			6,000			37,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[27]	7,000			7,000			11,000
Cash [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[28]	164,353			164,353			19,966
Cash [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[28]	157,409			157,409			9,418
Cash [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[28]	0			0			0
Cash [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[28]	0			0			0
Cash [Member] | Indiana Michigan Power Co [Member] | Fair Value Inputs Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[28]	6,944			6,944			10,548
Fixed Income Funds [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		816,000			816,000			953,000
Fixed Income Funds [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
Fixed Income Funds [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		816,000			816,000			953,000
Fixed Income Funds [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
Fixed Income Funds [Member] | Fair Value Inputs Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		816,480			816,480			953,387
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		816,480			816,480			953,387
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member] | Fair Value Inputs Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
Mutual Funds Fixed Income [Member]
Assets, Fair Value Disclosure [Abstract]
Other Temporary Investments		90,000			90,000			81,000
Mutual Funds Fixed Income [Member] | Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Other Temporary Investments		90,000			90,000			81,000
Mutual Funds Fixed Income [Member] | Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Other Temporary Investments		0			0			0
Mutual Funds Fixed Income [Member] | Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Other Temporary Investments		0			0			0
Mutual Funds Fixed Income [Member] | Fair Value Inputs Other [Member]
Assets, Fair Value Disclosure [Abstract]
Other Temporary Investments		0			0			0
Domestic [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[29]	1,067,000			1,067,000			1,123,000
Domestic [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[29]	1,067,000			1,067,000			1,123,000
Domestic [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[29]	0			0			0
Domestic [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[29]	0			0			0
Domestic [Member] | Fair Value Inputs Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[29]	0			0			0
Domestic [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[30]	1,066,427			1,066,427			1,122,379
Domestic [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[30]	1,066,427			1,066,427			1,122,379
Domestic [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[30]	0			0			0
Domestic [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[30]	0			0			0
Domestic [Member] | Indiana Michigan Power Co [Member] | Fair Value Inputs Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	[30]	0			0			0
Mutual Funds Equity [Member]
Assets, Fair Value Disclosure [Abstract]
Other Temporary Investments	[29]	24,000			24,000			25,000
Mutual Funds Equity [Member] | Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Other Temporary Investments	[29]	24,000			24,000			25,000
Mutual Funds Equity [Member] | Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Other Temporary Investments	[29]	0			0			0
Mutual Funds Equity [Member] | Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Other Temporary Investments	[29]	0			0			0
Mutual Funds Equity [Member] | Fair Value Inputs Other [Member]
Assets, Fair Value Disclosure [Abstract]
Other Temporary Investments	[29]	0			0			0
Cash and Cash Equivalents [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		164,000			164,000			20,000
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		164,353			164,353			19,966
US Government Agencies Debt Securities [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		704,000			704,000			697,000
US Government Agencies Debt Securities [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
US Government Agencies Debt Securities [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		704,000			704,000			697,000
US Government Agencies Debt Securities [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
US Government Agencies Debt Securities [Member] | Fair Value Inputs Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		704,344			704,344			697,042
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		704,344			704,344			697,042
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member] | Fair Value Inputs Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
Corporate Debt [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		62,000			62,000			48,000
Corporate Debt [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
Corporate Debt [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		62,000			62,000			48,000
Corporate Debt [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
Corporate Debt [Member] | Fair Value Inputs Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
Corporate Debt [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		62,118			62,118			47,792
Corporate Debt [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
Corporate Debt [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		62,118			62,118			47,792
Corporate Debt [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
Corporate Debt [Member] | Indiana Michigan Power Co [Member] | Fair Value Inputs Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
State and Local Jurisdiction [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		50,000			50,000			208,000
State and Local Jurisdiction [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
State and Local Jurisdiction [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		50,000			50,000			208,000
State and Local Jurisdiction [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
State and Local Jurisdiction [Member] | Fair Value Inputs Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		50,018			50,018			208,553
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member] | Level 1 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member] | Level 2 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		50,018			50,018			208,553
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member] | Level 3 [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		0			0			0
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member] | Fair Value Inputs Other [Member]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts		$ 0			$ 0			$ 0

[1] Amounts in ''Other'' column primarily represent cash deposits in bank accounts with financial institutions or with third parties. Level 1 and Level 2 amounts primarily represent investments in money market funds.

[2] Included in revenues on the condensed statements of income.

[3] Represents the change in fair value between the beginning of the reporting period and the settlement of the risk management commodity contract.

[4] Represents the settlement of risk management commodity contracts for the reporting period.

[5] Represents existing assets or liabilities that were previously categorized as Level 2.

[6] Transfers are recognized based on their value at the beginning of the reporting period that the transfer occurred.

[7] Represents existing assets or liabilities that were previously categorized as Level 3.

[8] Relates to the net gains (losses) of those contracts that are not reflected on the condensed statements of income. These net gains (losses) are recorded as regulatory liabilities/assets.

[9] Represents average price of credit default swaps used to calculate counterparty credit risk, reported in basis points.

[10] Amounts in ''Other'' column primarily represent counterparty netting of risk management and hedging contracts and associated cash collateral under the accounting guidance for ''Derivatives and Hedging.''

[11] The September 30, 2015 maturity of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), is as follows: Level 1 matures ($4) million in 2015 and ($12) million in periods 2016-2018; Level 2 matures $5 million in 2015, $28 million in periods 2016-2018, $3 million in periods 2019-2020 and $2 million in periods 2021-2032; Level 3 matures $2 million in 2015, $63 million in periods 2016-2018, $25 million in periods 2019-2020 and $82 million in periods 2021-2032. Risk management commodity contracts are substantially comprised of power contracts.

[12] The December 31, 2014 maturity of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), is as follows: Level 1 matures $(18) million in 2015 and ($10) million in periods 2016-2018; Level 2 matures $31 million in 2015, $52 million in periods 2016-2018, $12 million in periods 2019-2020 and $1 million in periods 2021-2030; Level 3 matures $50 million in 2015, $29 million in periods 2016-2018, $9 million in periods 2019-2020 and $66 million in periods 2021-2030. Risk management commodity contracts are substantially comprised of power contracts.

[13] Represents market prices in dollars per MWh.

[14] Amounts in "Other" column primarily represent cash deposits in bank accounts with financial institutions or with third parties. Level 1 amounts primarily represent investment in money market funds.

[15] Includes both affiliated and nonaffiliated transactions.

[16] Included in revenues on the condensed statements of income.

[17] Represents the change in fair value between the beginning of the reporting period and the settlement of the risk management commodity contract.

[18] Represents the settlement of risk management commodity contracts for the reporting period.

[19] Represents existing assets or liabilities that were previously categorized as Level 2.

[20] Transfers are recognized based on their value at the beginning of the reporting period that the transfer occurred.

[21] Represents existing assets or liabilities that were previously categorized as Level 3.

[22] Relates to the net gains (losses) of those contracts that are not reflected on the condensed statements of income. These net gains (losses) are recorded as regulatory liabilities/assets.

[23] Amounts in “Other” column primarily represent counterparty netting of risk management and hedging contracts and associated cash collateral under the accounting guidance for “Derivatives and Hedging.”

[24] Substantially comprised of power contracts for APCo, I&M and OPCo and coal contracts for PSO and SWEPCo.

[25] Represents market prices in dollars per MWh.

[26] Primarily represents amounts held for the repayment of debt.

[27] Amounts in ''Other'' column primarily represent accrued interest receivables from financial institutions. Level 1 amounts primarily represent investments in money market funds.

[28] Amounts in “Other” column primarily represent accrued interest receivables from financial institutions. Level 1 amounts primarily represent investments in money market funds.

[29] Amounts represent publicly traded equity securities and equity-based mutual funds.

[30] Amounts represent publicly traded equity securities and equity-based mutual funds.