Fair Value Long-term Debt, Other Temporary Investments, Nuclear Trusts (Details) (USD $)	3 Months Ended			6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013	Jun. 30, 2014		Jun. 30, 2013	Dec. 31, 2013
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	$ 18,125,000,000			$ 18,125,000,000			$ 18,377,000,000
Long Term Debt, Fair Value	20,284,000,000			20,284,000,000			19,672,000,000
Other Temporary Investments
Cost	365,000,000			365,000,000			342,000,000
Gross Unrealized Gains	12,000,000			12,000,000			11,000,000
Gross Unrealized Losses	0			0			0
Estimated Fair Value	377,000,000			377,000,000			353,000,000
Debt and Equity Securities Within Other Temporary Investments [Abstract]
Proceeds from Investment Sales	0		0	0		0
Purchases of Investments	0		0	1,000,000		11,000,000
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	2,019,000,000			2,019,000,000			1,932,000,000
Gross Unrealized Gains	599,000,000			599,000,000			535,000,000
Other-Than-Temporary Impairments	(107,000,000)			(107,000,000)			(87,000,000)
Securities Activity Within Decommissioning and SNF Trusts [Abstract]
Proceeds from Investment Sales	335,000,000		217,000,000	483,000,000		385,000,000
Purchases of Investments	345,000,000		227,000,000	509,000,000		412,000,000
Gross Realized Gains on Investment Sales	9,000,000		9,000,000	17,000,000		12,000,000
Gross Realized Losses on Investment Sales	8,000,000		8,000,000	9,000,000		10,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	2,019,000,000			2,019,000,000			1,932,000,000
Fair Value Measurements (Textuals) [Abstract]
Adjusted Cost of Debt Securities	894,000,000			894,000,000			872,000,000
Adjusted Cost of Domestic Equity Securities	511,000,000			511,000,000			506,000,000
Appalachian Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	3,992,617,000			3,992,617,000			4,194,357,000
Long Term Debt, Fair Value	4,624,573,000			4,624,573,000			4,587,079,000
Indiana Michigan Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	1,979,041,000			1,979,041,000			2,039,016,000
Long Term Debt, Fair Value	2,193,580,000			2,193,580,000			2,174,891,000
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	2,018,506,000			2,018,506,000			1,931,610,000
Gross Unrealized Gains	598,432,000			598,432,000			534,850,000
Other-Than-Temporary Impairments	(107,105,000)			(107,105,000)			(86,994,000)
Securities Activity Within Decommissioning and SNF Trusts [Abstract]
Proceeds from Investment Sales	334,834,000		218,272,000	482,534,000		385,942,000
Purchases of Investments	344,324,000		227,470,000	508,835,000		411,769,000
Gross Realized Gains on Investment Sales	9,077,000		8,575,000	17,218,000		11,898,000
Gross Realized Losses on Investment Sales	7,834,000		7,397,000	8,708,000		9,712,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	2,018,506,000			2,018,506,000			1,931,610,000
Fair Value Measurements (Textuals) [Abstract]
Adjusted Cost of Debt Securities	894,000,000			894,000,000			872,000,000
Adjusted Cost of Domestic Equity Securities	511,000,000			511,000,000			506,000,000
Ohio Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	2,370,952,000			2,370,952,000			2,735,175,000
Long Term Debt, Fair Value	2,760,808,000			2,760,808,000			3,007,191,000
Other Temporary Investments
Cash	43,003,000			43,003,000			19,387,000
Public Service Co Of Oklahoma [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	1,041,075,000			1,041,075,000			999,810,000
Long Term Debt, Fair Value	1,207,009,000			1,207,009,000			1,111,149,000
Southwestern Electric Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	2,041,885,000			2,041,885,000			2,043,332,000
Long Term Debt, Fair Value	2,330,329,000			2,330,329,000			2,214,730,000
Cash [Member]
Other Temporary Investments
Cost	272,000,000			272,000,000			250,000,000
Gross Unrealized Gains	0			0			0
Gross Unrealized Losses	0			0			0
Estimated Fair Value	272,000,000	[1]		272,000,000	[1]		250,000,000	[1]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	15,000,000	[2]		15,000,000	[2]		19,000,000	[2]
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	15,000,000	[2]		15,000,000	[2]		19,000,000	[2]
Cash [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	14,847,000	[3]		14,847,000	[3]		18,804,000	[3]
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	14,847,000	[3]		14,847,000	[3]		18,804,000	[3]
Fixed Income Funds [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	936,000,000			936,000,000			901,000,000
Gross Unrealized Gains	42,000,000			42,000,000			29,000,000
Other-Than-Temporary Impairments	(28,000,000)			(28,000,000)			(5,000,000)
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	936,000,000			936,000,000			901,000,000
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	935,640,000			935,640,000			900,295,000
Gross Unrealized Gains	41,282,000			41,282,000			29,312,000
Other-Than-Temporary Impairments	(28,016,000)			(28,016,000)			(5,317,000)
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	935,640,000			935,640,000			900,295,000
Mutual Funds Fixed Income [Member]
Other Temporary Investments
Cost	80,000,000			80,000,000			80,000,000
Gross Unrealized Gains	0			0			0
Gross Unrealized Losses	0			0			0
Estimated Fair Value	80,000,000			80,000,000			80,000,000
Domestic [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	1,068,000,000	[4]		1,068,000,000	[4]		1,012,000,000	[4]
Gross Unrealized Gains	557,000,000			557,000,000			506,000,000
Other-Than-Temporary Impairments	(79,000,000)			(79,000,000)			(82,000,000)
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	1,068,000,000	[4]		1,068,000,000	[4]		1,012,000,000	[4]
Domestic [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	1,068,019,000	[4]		1,068,019,000	[4]		1,012,511,000	[4]
Gross Unrealized Gains	557,150,000			557,150,000			505,538,000
Other-Than-Temporary Impairments	(79,089,000)			(79,089,000)			(81,677,000)
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	1,068,019,000	[4]		1,068,019,000	[4]		1,012,511,000	[4]
Mutual Funds Equity [Member]
Other Temporary Investments
Cost	13,000,000			13,000,000			12,000,000
Gross Unrealized Gains	12,000,000			12,000,000			11,000,000
Gross Unrealized Losses	0			0			0
Estimated Fair Value	25,000,000	[4]		25,000,000	[4]		23,000,000	[4]
Cash and Cash Equivalents [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	15,000,000			15,000,000			19,000,000
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			19,000,000
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	14,847,000			14,847,000			18,804,000
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	14,847,000			14,847,000			18,804,000
US Government Agencies Debt Securities [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	580,000,000			580,000,000			609,000,000
Gross Unrealized Gains	37,000,000			37,000,000			26,000,000
Other-Than-Temporary Impairments	(26,000,000)			(26,000,000)			(4,000,000)
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	580,000,000			580,000,000			609,000,000
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	579,840,000			579,840,000			608,875,000
Gross Unrealized Gains	36,602,000			36,602,000			26,114,000
Other-Than-Temporary Impairments	(26,358,000)			(26,358,000)			(3,824,000)
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	579,840,000			579,840,000			608,875,000
Corporate Debt [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	47,000,000			47,000,000			37,000,000
Gross Unrealized Gains	4,000,000			4,000,000			2,000,000
Other-Than-Temporary Impairments	(1,000,000)			(1,000,000)			(1,000,000)
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	47,000,000			47,000,000			37,000,000
Corporate Debt [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	46,567,000			46,567,000			36,782,000
Gross Unrealized Gains	3,791,000			3,791,000			2,450,000
Other-Than-Temporary Impairments	(1,068,000)			(1,068,000)			(1,123,000)
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	46,567,000			46,567,000			36,782,000
State and Local Jurisdiction [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	309,000,000			309,000,000			255,000,000
Gross Unrealized Gains	1,000,000			1,000,000			1,000,000
Other-Than-Temporary Impairments	(1,000,000)			(1,000,000)			0
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	309,000,000			309,000,000			255,000,000
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	309,233,000			309,233,000			254,638,000
Gross Unrealized Gains	889,000			889,000			748,000
Other-Than-Temporary Impairments	(590,000)			(590,000)			(370,000)
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	309,233,000			309,233,000			254,638,000
Within One Year [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	39,000,000			39,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	39,000,000			39,000,000
Within One Year [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	38,967,000			38,967,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	38,967,000			38,967,000
One Year To Five Year [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	414,000,000			414,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	414,000,000			414,000,000
One Year To Five Year [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	414,273,000			414,273,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	414,273,000			414,273,000
Five Year To Ten Year [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	208,000,000			208,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	208,000,000			208,000,000
Five Year To Ten Year [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	207,156,000			207,156,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	207,156,000			207,156,000
After Ten Year [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	275,000,000			275,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	275,000,000			275,000,000
After Ten Year [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	275,244,000			275,244,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	$ 275,244,000			$ 275,244,000

[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.