Fair Value Long-term Debt, Other Temporary Investments, Nuclear Trusts (Details) (USD $)	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013	Dec. 31, 2013
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	$ 18,087,000,000			$ 18,377,000,000
Long Term Debt, Fair Value	19,738,000,000			19,672,000,000
Other Temporary Investments
Cost	299,000,000			342,000,000
Gross Unrealized Gains	11,000,000			11,000,000
Gross Unrealized Losses	0			0
Estimated Fair Value	310,000,000			353,000,000
Debt and Equity Securities Within Other Temporary Investments [Abstract]
Proceeds from Investment Sales	0		0
Purchases of Investments	1,000,000		11,000,000
Gross Realized Gains on Investment Sales	0		0
Gross Realized Losses on Investment Sales	0		0
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	1,962,000,000			1,932,000,000
Gross Unrealized Gains	550,000,000			535,000,000
Other-Than-Temporary Impairments	85,000,000			87,000,000
Securities Activity Within Decommissioning and SNF Trusts [Abstract]
Proceeds from Investment Sales	148,000,000		168,000,000
Purchases of Investments	164,000,000		185,000,000
Gross Realized Gains on Investment Sales	8,000,000		3,000,000
Gross Realized Losses on Investment Sales	1,000,000		2,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	1,962,000,000			1,932,000,000
Fair Value Measurements (Textuals) [Abstract]
Adjusted Cost of Debt Securities	894,000,000			872,000,000
Adjusted Cost of Domestic Equity Securities	506,000,000			506,000,000
Appalachian Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	4,194,516,000			4,194,357,000
Long Term Debt, Fair Value	4,730,819,000			4,587,079,000
Indiana Michigan Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	2,012,844,000			2,039,016,000
Long Term Debt, Fair Value	2,203,640,000			2,174,891,000
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	1,962,151,000			1,931,610,000
Gross Unrealized Gains	549,664,000			534,850,000
Other-Than-Temporary Impairments	84,626,000			86,994,000
Securities Activity Within Decommissioning and SNF Trusts [Abstract]
Proceeds from Investment Sales	147,700,000		167,670,000
Purchases of Investments	164,511,000		184,299,000
Gross Realized Gains on Investment Sales	8,141,000		3,323,000
Gross Realized Losses on Investment Sales	874,000		2,315,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	1,962,151,000			1,931,610,000
Fair Value Measurements (Textuals) [Abstract]
Adjusted Cost of Debt Securities	894,000,000			872,000,000
Adjusted Cost of Domestic Equity Securities	506,000,000			506,000,000
Ohio Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	2,510,285,000			2,735,175,000
Long Term Debt, Fair Value	2,869,364,000			3,007,191,000
Public Service Co Of Oklahoma [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	1,049,793,000			999,810,000
Long Term Debt, Fair Value	1,200,741,000			1,111,149,000
Southwestern Electric Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	2,041,796,000			2,043,332,000
Long Term Debt, Fair Value	2,277,262,000			2,214,730,000
Cash [Member]
Other Temporary Investments
Cost	206,000,000			250,000,000
Gross Unrealized Gains	0			0
Gross Unrealized Losses	0			0
Estimated Fair Value	206,000,000	[1]		250,000,000	[1]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	12,000,000	[2]		19,000,000	[2]
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	12,000,000	[2]		19,000,000	[2]
Cash [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	12,439,000	[3]		18,804,000	[3]
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	12,439,000	[3]		18,804,000	[3]
Fixed Income Funds [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	930,000,000			901,000,000
Gross Unrealized Gains	36,000,000			29,000,000
Other-Than-Temporary Impairments	5,000,000			5,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	930,000,000			901,000,000
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	929,567,000			900,295,000
Gross Unrealized Gains	35,861,000			29,312,000
Other-Than-Temporary Impairments	5,063,000			5,317,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	929,567,000			900,295,000
Mutual Funds Fixed Income [Member]
Other Temporary Investments
Cost	80,000,000			80,000,000
Gross Unrealized Gains	0			0
Gross Unrealized Losses	0			0
Estimated Fair Value	80,000,000			80,000,000
Domestic [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	1,020,000,000	[4]		1,012,000,000	[4]
Gross Unrealized Gains	514,000,000			506,000,000
Other-Than-Temporary Impairments	80,000,000			82,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	1,020,000,000	[4]		1,012,000,000	[4]
Domestic [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	1,020,145,000	[4]		1,012,511,000	[4]
Gross Unrealized Gains	513,803,000			505,538,000
Other-Than-Temporary Impairments	79,563,000			81,677,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	1,020,145,000	[4]		1,012,511,000	[4]
Mutual Funds Equity [Member]
Other Temporary Investments
Cost	13,000,000			12,000,000
Gross Unrealized Gains	11,000,000			11,000,000
Gross Unrealized Losses	0			0
Estimated Fair Value	24,000,000	[4]		23,000,000	[4]
Cash and Cash Equivalents [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	12,000,000			19,000,000
Gross Unrealized Gains	0			0
Other-Than-Temporary Impairments	0			0
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	12,000,000			19,000,000
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	12,439,000			18,804,000
Gross Unrealized Gains	0			0
Other-Than-Temporary Impairments	0			0
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	12,439,000			18,804,000
US Government Agencies Debt Securities [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	606,000,000			609,000,000
Gross Unrealized Gains	31,000,000			26,000,000
Other-Than-Temporary Impairments	4,000,000			4,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	606,000,000			609,000,000
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	606,228,000			608,875,000
Gross Unrealized Gains	31,666,000			26,114,000
Other-Than-Temporary Impairments	3,621,000			3,824,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	606,228,000			608,875,000
Corporate Debt [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	43,000,000			37,000,000
Gross Unrealized Gains	4,000,000			2,000,000
Other-Than-Temporary Impairments	1,000,000			1,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	43,000,000			37,000,000
Corporate Debt [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	42,727,000			36,782,000
Gross Unrealized Gains	3,223,000			2,450,000
Other-Than-Temporary Impairments	1,097,000			1,123,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	42,727,000			36,782,000
State and Local Jurisdiction [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	281,000,000			255,000,000
Gross Unrealized Gains	1,000,000			1,000,000
Other-Than-Temporary Impairments	0			0
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	281,000,000			255,000,000
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	280,612,000			254,638,000
Gross Unrealized Gains	972,000			748,000
Other-Than-Temporary Impairments	345,000			370,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	280,612,000			254,638,000
Within One Year [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	82,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	82,000,000
Within One Year [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	82,190,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	82,190,000
One Year To Five Year [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	386,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	386,000,000
One Year To Five Year [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	386,173,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	386,173,000
Five Year To Ten Year [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	193,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	193,000,000
Five Year To Ten Year [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	193,018,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	193,018,000
After Ten Year [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	269,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	269,000,000
After Ten Year [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	268,186,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	$ 268,186,000

[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.