Fair Value Long-term Debt, Other Temporary Investments, Nuclear Trusts (Details) (USD $)	3 Months Ended			9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013	Sep. 30, 2014		Sep. 30, 2013	Dec. 31, 2013
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	$ 18,058,000,000			$ 18,058,000,000			$ 18,377,000,000
Long Term Debt, Fair Value	20,237,000,000			20,237,000,000			19,672,000,000
Other Temporary Investments
Cost	306,000,000			306,000,000			342,000,000
Gross Unrealized Gains	12,000,000			12,000,000			11,000,000
Gross Unrealized Losses	0			0			0
Estimated Fair Value	318,000,000			318,000,000			353,000,000
Debt and Equity Securities Within Other Temporary Investments [Abstract]
Proceeds from Investment Sales	0		0	0		0
Purchases of Investments	0		6,000,000	1,000,000		17,000,000
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	2,020,000,000			2,020,000,000			1,932,000,000
Gross Unrealized Gains	585,000,000			585,000,000			535,000,000
Other-Than-Temporary Impairments	(84,000,000)			(84,000,000)			(87,000,000)
Securities Activity Within Decommissioning and SNF Trusts [Abstract]
Proceeds from Investment Sales	263,000,000		250,000,000	746,000,000		635,000,000
Purchases of Investments	281,000,000		264,000,000	790,000,000		676,000,000
Gross Realized Gains on Investment Sales	8,000,000		4,000,000	25,000,000		16,000,000
Gross Realized Losses on Investment Sales	1,000,000		2,000,000	10,000,000		12,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	2,020,000,000			2,020,000,000			1,932,000,000
Fair Value Measurements (Textuals) [Abstract]
Adjusted Cost of Debt Securities	901,000,000			901,000,000			872,000,000
Adjusted Cost of Domestic Equity Securities	521,000,000			521,000,000			506,000,000
Appalachian Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	3,980,107,000			3,980,107,000			4,194,357,000
Long Term Debt, Fair Value	4,642,320,000			4,642,320,000			4,587,079,000
Indiana Michigan Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	1,948,931,000			1,948,931,000			2,039,016,000
Long Term Debt, Fair Value	2,166,248,000			2,166,248,000			2,174,891,000
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	2,020,248,000			2,020,248,000			1,931,610,000
Gross Unrealized Gains	585,196,000			585,196,000			534,850,000
Other-Than-Temporary Impairments	(83,531,000)			(83,531,000)			(86,994,000)
Securities Activity Within Decommissioning and SNF Trusts [Abstract]
Proceeds from Investment Sales	263,738,000		249,314,000	746,272,000		635,256,000
Purchases of Investments	280,626,000		263,958,000	789,461,000		675,727,000
Gross Realized Gains on Investment Sales	7,617,000		4,113,000	24,835,000		16,011,000
Gross Realized Losses on Investment Sales	1,739,000		2,147,000	10,447,000		11,859,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	2,020,248,000			2,020,248,000			1,931,610,000
Fair Value Measurements (Textuals) [Abstract]
Adjusted Cost of Debt Securities	901,000,000			901,000,000			872,000,000
Adjusted Cost of Domestic Equity Securities	521,000,000			521,000,000			506,000,000
Ohio Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	2,297,004,000			2,297,004,000			2,735,175,000
Long Term Debt, Fair Value	2,688,426,000			2,688,426,000			3,007,191,000
Other Temporary Investments
Cash	17,734,000			17,734,000			19,387,000
Public Service Co Of Oklahoma [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	1,041,056,000			1,041,056,000			999,810,000
Long Term Debt, Fair Value	1,205,687,000			1,205,687,000			1,111,149,000
Southwestern Electric Power Co [Member]
Book Values and Fair Values of Long - term Debt
Total Long-term Debt Outstanding	2,140,348,000			2,140,348,000			2,043,332,000
Long Term Debt, Fair Value	2,401,635,000			2,401,635,000			2,214,730,000
Cash [Member]
Other Temporary Investments
Cost	213,000,000			213,000,000			250,000,000
Gross Unrealized Gains	0			0			0
Gross Unrealized Losses	0			0			0
Estimated Fair Value	213,000,000	[1]		213,000,000	[1]		250,000,000	[1]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	13,000,000	[2]		13,000,000	[2]		19,000,000	[2]
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	13,000,000	[2]		13,000,000	[2]		19,000,000	[2]
Cash [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	13,188,000	[3]		13,188,000	[3]		18,804,000	[3]
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	13,188,000	[3]		13,188,000	[3]		18,804,000	[3]
Fixed Income Funds [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	941,000,000			941,000,000			901,000,000
Gross Unrealized Gains	40,000,000			40,000,000			29,000,000
Other-Than-Temporary Impairments	(4,000,000)			(4,000,000)			(5,000,000)
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	941,000,000			941,000,000			901,000,000
Fixed Income Funds [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	941,346,000			941,346,000			900,295,000
Gross Unrealized Gains	40,201,000			40,201,000			29,312,000
Other-Than-Temporary Impairments	(4,202,000)			(4,202,000)			(5,317,000)
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	941,346,000			941,346,000			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	1,066,000,000	[4]		1,066,000,000	[4]		1,012,000,000	[4]
Gross Unrealized Gains	545,000,000			545,000,000			506,000,000
Other-Than-Temporary Impairments	(80,000,000)			(80,000,000)			(82,000,000)
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	1,066,000,000	[4]		1,066,000,000	[4]		1,012,000,000	[4]
Domestic [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	1,065,714,000	[4]		1,065,714,000	[4]		1,012,511,000	[4]
Gross Unrealized Gains	544,995,000			544,995,000			505,538,000
Other-Than-Temporary Impairments	(79,329,000)			(79,329,000)			(81,677,000)
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	1,065,714,000	[4]		1,065,714,000	[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	13,000,000			13,000,000			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	13,000,000			13,000,000			19,000,000
Cash and Cash Equivalents [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	13,188,000			13,188,000			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	13,188,000			13,188,000			18,804,000
US Government Agencies Debt Securities [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	609,000,000			609,000,000			609,000,000
Gross Unrealized Gains	35,000,000			35,000,000			26,000,000
Other-Than-Temporary Impairments	(3,000,000)			(3,000,000)			(4,000,000)
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	609,000,000			609,000,000			609,000,000
US Government Agencies Debt Securities [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	609,441,000			609,441,000			608,875,000
Gross Unrealized Gains	35,262,000			35,262,000			26,114,000
Other-Than-Temporary Impairments	(2,941,000)			(2,941,000)			(3,824,000)
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	609,441,000			609,441,000			608,875,000
Corporate Debt [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	46,000,000			46,000,000			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	46,000,000			46,000,000			37,000,000
Corporate Debt [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	46,409,000			46,409,000			36,782,000
Gross Unrealized Gains	3,630,000			3,630,000			2,450,000
Other-Than-Temporary Impairments	(1,046,000)			(1,046,000)			(1,123,000)
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	46,409,000			46,409,000			36,782,000
State and Local Jurisdiction [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	286,000,000			286,000,000			255,000,000
Gross Unrealized Gains	1,000,000			1,000,000			1,000,000
Other-Than-Temporary Impairments	0			0			0
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	286,000,000			286,000,000			255,000,000
State and Local Jurisdiction [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	285,496,000			285,496,000			254,638,000
Gross Unrealized Gains	1,309,000			1,309,000			748,000
Other-Than-Temporary Impairments	(215,000)			(215,000)			(370,000)
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	285,496,000			285,496,000			254,638,000
Within One Year [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	103,000,000			103,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	103,000,000			103,000,000
Within One Year [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	103,652,000			103,652,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	103,652,000			103,652,000
One Year To Five Year [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	377,000,000			377,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	377,000,000			377,000,000
One Year To Five Year [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	376,783,000			376,783,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	376,783,000			376,783,000
Five Year To Ten Year [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	198,000,000			198,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	198,000,000			198,000,000
Five Year To Ten Year [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	198,064,000			198,064,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	198,064,000			198,064,000
After Ten Year [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	263,000,000			263,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	263,000,000			263,000,000
After Ten Year [Member] | Indiana Michigan Power Co [Member]
Nuclear Trust Fund Investments [Abstract]
Estimated Fair Value	262,847,000			262,847,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	$ 262,847,000			$ 262,847,000

[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.