Fair Value Long-term Debt, Other Temporary Investments, Nuclear Trusts (Details) (USD $)	3 Months Ended			9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012	Dec. 31, 2012
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	$ 17,568,000,000			$ 17,568,000,000			$ 17,757,000,000
Long Term Debt, Fair Value	19,316,000,000			19,316,000,000			20,907,000,000
Other Temporary Investments
Cost	280,000,000			280,000,000			316,000,000
Gross Unrealized Gains	8,000,000			8,000,000			8,000,000
Gross Unrealized Losses	0			0			0
Estimated Fair Value	288,000,000			288,000,000			324,000,000
Debt and Equity Securities Within Other Temporary Investments [Abstract]
Proceeds from Investment Sales	0		0	0		0
Purchases of Investments	6,000,000		0	17,000,000		1,000,000
Gross Realized Gains on Investment Sales	0		0	0		0
Gross Realized Losses on Investment Sales	0		0	0		0
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	1,839,000,000			1,839,000,000			1,706,000,000
Gross Unrealized Gains	452,000,000			452,000,000			349,000,000
Other-Than-Temporary Impairments	86,000,000			86,000,000			80,000,000
Securities Activity Within Decommissioning and SNF Trusts [Abstract]
Proceeds from Investment Sales	250,000,000		182,000,000	635,000,000		699,000,000
Purchases of Investments	264,000,000		199,000,000	676,000,000		744,000,000
Gross Realized Gains on Investment Sales	4,000,000		2,000,000	16,000,000		7,000,000
Gross Realized Losses on Investment Sales	2,000,000		1,000,000	12,000,000		3,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	1,839,000,000			1,839,000,000			1,706,000,000
Fair Value Measurements (Textuals) [Abstract]
Adjusted Cost of Debt Securities	866,000,000			866,000,000			889,000,000
Adjusted Cost of Domestic Equity Securities	506,000,000			506,000,000			451,000,000
Appalachian Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	3,427,917,000			3,427,917,000			3,702,442,000
Long Term Debt, Fair Value	3,957,321,000			3,957,321,000			4,555,143,000
Indiana Michigan Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	2,271,613,000			2,271,613,000			2,057,666,000
Long Term Debt, Fair Value	2,461,671,000			2,461,671,000			2,372,017,000
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	1,839,118,000			1,839,118,000			1,705,772,000
Gross Unrealized Gains	452,843,000			452,843,000			348,776,000
Other-Than-Temporary Impairments	85,931,000			85,931,000			79,519,000
Securities Activity Within Decommissioning and SNF Trusts [Abstract]
Proceeds from Investment Sales	249,314,000		181,988,000	635,256,000		698,567,000
Purchases of Investments	263,958,000		199,150,000	675,727,000		744,131,000
Gross Realized Gains on Investment Sales	4,113,000		2,046,000	16,011,000		6,978,000
Gross Realized Losses on Investment Sales	2,147,000		924,000	11,859,000		3,143,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	1,839,118,000			1,839,118,000			1,705,772,000
Fair Value Measurements (Textuals) [Abstract]
Adjusted Cost of Debt Securities	866,000,000			866,000,000			889,000,000
Adjusted Cost of Domestic Equity Securities	506,000,000			506,000,000			451,000,000
Ohio Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	3,698,574,000			3,698,574,000			3,860,440,000
Long Term Debt, Fair Value	4,071,613,000			4,071,613,000			4,560,337,000
Public Service Co Of Oklahoma [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	949,826,000			949,826,000			949,871,000
Long Term Debt, Fair Value	1,090,934,000			1,090,934,000			1,175,759,000
Southwestern Electric Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	2,043,244,000			2,043,244,000			2,046,228,000
Long Term Debt, Fair Value	2,254,078,000			2,254,078,000			2,400,509,000
Cash [Member]
Other Temporary Investments
Cost	188,000,000			188,000,000			241,000,000
Gross Unrealized Gains	0			0			0
Gross Unrealized Losses	0			0			0
Estimated Fair Value	188,000,000	[1]		188,000,000	[1]		241,000,000	[1]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	15,000,000	[2]		15,000,000	[2]		17,000,000	[2]
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	15,000,000	[2]		15,000,000	[2]		17,000,000	[2]
Cash [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	14,438,000	[3]		14,438,000	[3]		16,783,000	[3]
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	14,438,000	[3]		14,438,000	[3]		16,783,000	[3]
Fixed Income Funds [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	903,000,000			903,000,000			953,000,000
Gross Unrealized Gains	37,000,000			37,000,000			64,000,000
Other-Than-Temporary Impairments	5,000,000			5,000,000			3,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	903,000,000			903,000,000			953,000,000
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	903,388,000			903,388,000			953,407,000
Gross Unrealized Gains	37,912,000			37,912,000			64,177,000
Other-Than-Temporary Impairments	4,806,000			4,806,000			2,962,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	903,388,000			903,388,000			953,407,000
Mutual Funds Fixed Income [Member]
Other Temporary Investments
Cost	79,000,000			79,000,000			65,000,000
Gross Unrealized Gains	0			0			2,000,000
Gross Unrealized Losses	0			0			0
Estimated Fair Value	79,000,000			79,000,000			67,000,000
Domestic [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	921,000,000	[4]		921,000,000	[4]		736,000,000	[4]
Gross Unrealized Gains	415,000,000			415,000,000			285,000,000
Other-Than-Temporary Impairments	81,000,000			81,000,000			77,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	921,000,000	[4]		921,000,000	[4]		736,000,000	[4]
Domestic [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	921,292,000	[4]		921,292,000	[4]		735,582,000	[4]
Gross Unrealized Gains	414,931,000			414,931,000			284,599,000
Other-Than-Temporary Impairments	81,125,000			81,125,000			76,557,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	921,292,000	[4]		921,292,000	[4]		735,582,000	[4]
Mutual Funds Equity [Member]
Other Temporary Investments
Cost	13,000,000			13,000,000			10,000,000
Gross Unrealized Gains	8,000,000			8,000,000			6,000,000
Gross Unrealized Losses	0			0			0
Estimated Fair Value	21,000,000	[4]		21,000,000	[4]		16,000,000	[4]
Cash and Cash Equivalents [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	15,000,000			15,000,000			17,000,000
Gross Unrealized Gains	0			0			0
Other-Than-Temporary Impairments	0			0			0
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	15,000,000			15,000,000			17,000,000
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	14,438,000			14,438,000			16,783,000
Gross Unrealized Gains	0			0			0
Other-Than-Temporary Impairments	0			0			0
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	14,438,000			14,438,000			16,783,000
US Government Agencies Debt Securities [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	621,000,000			621,000,000			648,000,000
Gross Unrealized Gains	34,000,000			34,000,000			58,000,000
Other-Than-Temporary Impairments	3,000,000			3,000,000			1,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	621,000,000			621,000,000			648,000,000
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	620,944,000			620,944,000			647,918,000
Gross Unrealized Gains	34,377,000			34,377,000			58,268,000
Other-Than-Temporary Impairments	2,662,000			2,662,000			747,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	620,944,000			620,944,000			647,918,000
Corporate Debt [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	38,000,000			38,000,000			35,000,000
Gross Unrealized Gains	2,000,000			2,000,000			5,000,000
Other-Than-Temporary Impairments	2,000,000			2,000,000			1,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	38,000,000			38,000,000			35,000,000
Corporate Debt [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	38,272,000			38,272,000			35,399,000
Gross Unrealized Gains	2,684,000			2,684,000			4,903,000
Other-Than-Temporary Impairments	1,786,000			1,786,000			1,352,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	38,272,000			38,272,000			35,399,000
State and Local Jurisdiction [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	244,000,000			244,000,000			270,000,000
Gross Unrealized Gains	1,000,000			1,000,000			1,000,000
Other-Than-Temporary Impairments	0			0			1,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	244,000,000			244,000,000			270,000,000
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	244,172,000			244,172,000			270,090,000
Gross Unrealized Gains	851,000			851,000			1,006,000
Other-Than-Temporary Impairments	358,000			358,000			863,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	244,172,000			244,172,000			270,090,000
Within One Year [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	74,000,000			74,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	74,000,000			74,000,000
Within One Year [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	73,908,000			73,908,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	73,908,000			73,908,000
One Year To Five Year [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	378,000,000			378,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	378,000,000			378,000,000
One Year To Five Year [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	378,271,000			378,271,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	378,271,000			378,271,000
Five Year To Ten Year [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	210,000,000			210,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	210,000,000			210,000,000
Five Year To Ten Year [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	210,201,000			210,201,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	210,201,000			210,201,000
After Ten Year [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	241,000,000			241,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	241,000,000			241,000,000
After Ten Year [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	241,008,000			241,008,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	$ 241,008,000			$ 241,008,000

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

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

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