Fair Value Measurements (Details) (USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010		Dec. 31, 2010
Book Values and Fair Values of Long - term Debt
Long-term Debt	$ 16,450,000,000				$ 16,450,000,000				$ 16,811,000,000
Long Term Debt, Fair Value	19,003,000,000				19,003,000,000				18,285,000,000
Other Temporary Investments
Estimated Fair Value	240,000,000				240,000,000				416,000,000
Debt And Equity Securities Within Other Temporary Investments [Abstract]
Proceeds From Investment Sales	21,000,000		133,000,000		268,000,000		390,000,000
Purchases of Investments	0		192,000,000		153,000,000		413,000,000
Gross Realized Gains on Investment Sales	4,000,000		0		4,000,000		16,000,000
Gross Realized Losses on Investment Sales	0		0		0		0
Nuclear trust fund investments
Estimated Fair Value	1,513,000,000				1,513,000,000				1,515,000,000
Gross Unrealized Gains	208,000,000				208,000,000				209,000,000
Other-Than-Temporary Impairments	(88,000,000)				(88,000,000)				(126,000,000)
Securities activity within the decommissioning and SNF trusts
Proceeds from Investment Sales	361,000,000		495,000,000		826,000,000		1,087,000,000
Purchases of Investments	379,000,000		512,000,000		871,000,000		1,129,000,000
Gross Realized Gains on Investment Sales	18,000,000		1,000,000		30,000,000		7,000,000
Gross Realized Losses on Investment Sales	12,000,000		0		21,000,000		0
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	1,513,000,000				1,513,000,000				1,515,000,000
Assets:
Cash and Cash Equivalents	546,000,000	[1]			546,000,000	[1]			294,000,000	[1]
Total Other Temporary Investments	240,000,000				240,000,000				416,000,000
Risk Management Assets
Risk Management Assets	480,000,000				480,000,000				642,000,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	1,513,000,000				1,513,000,000				1,515,000,000
Total Assets	2,779,000,000				2,779,000,000				2,867,000,000
Liabilities:
Risk Management Liabilities	246,000,000				246,000,000				270,000,000
Changes in the fair value of net trading derivatives and other investments
Beginning Balance	77,000,000		100,000,000		85,000,000		62,000,000
Realized Gain (Loss) Included in Net Income (or Changes in Net Assets)	(16,000,000)	[2],[3]	(4,000,000)	[2],[3]	(11,000,000)	[2],[3]	4,000,000	[2],[3]
Unrealized Gain (Loss) Included in Net Income (or Changes in Net Assets) Relating to Assets Still Held at the Reporting Date	(5,000,000)	[2]	23,000,000	[2]	0	[2]	60,000,000	[2]
Realized and Unrealized Gains (Losses) Included in Other Comprehensive Income	0		0		0		0
Purchases, Issuances and Settlements	3,000,000	[4]	0	[4]	5,000,000	[4]	(18,000,000)	[4]
Transfers into Level 3	5,000,000	[5],[6]	5,000,000	[5],[6]	9,000,000	[5],[6]	14,000,000	[5],[6]
Transfers out of Level 3	(1,000,000)	[6],[7]	(22,000,000)	[6],[7]	(12,000,000)	[6],[7]	(26,000,000)	[6],[7]
Changes in Fair Value Allocated to Regulated Jurisdiction	1,000,000	[8]	9,000,000	[8]	(12,000,000)	[8]	15,000,000	[8]
Ending Balance	64,000,000		111,000,000		64,000,000		111,000,000
Fair Value Measurements (Textuals) [Abstract]
Adjusted Cost of Debt Securities	859,000,000				859,000,000				835,000,000
Adjusted Cost of Domestic Equity Securities	432,000,000				432,000,000				451,000,000
Risk Management Commodity Contracts [Member]
Risk Management Assets
Risk Management Assets	423,000,000	[10],[9]			423,000,000	[10],[9]			551,000,000	[11],[9]
Liabilities:
Risk Management Liabilities	208,000,000	[10],[9]			208,000,000	[10],[9]			263,000,000	[11],[9]
Risk Management Commodity Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	25,000,000	[10],[9]			25,000,000	[10],[9]			20,000,000	[11],[9]
Liabilities:
Risk Management Liabilities	25,000,000	[10],[9]			25,000,000	[10],[9]			25,000,000	[11],[9]
Risk Management Commodity Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	855,000,000	[10],[9]			855,000,000	[10],[9]			1,432,000,000	[11],[9]
Liabilities:
Risk Management Liabilities	734,000,000	[10],[9]			734,000,000	[10],[9]			1,325,000,000	[11],[9]
Risk Management Commodity Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	105,000,000	[10],[9]			105,000,000	[10],[9]			112,000,000	[11],[9]
Liabilities:
Risk Management Liabilities	41,000,000	[10],[9]			41,000,000	[10],[9]			27,000,000	[11],[9]
Risk Management Commodity Contracts [Member] | Fair Value Inputs Other [Member]
Risk Management Assets
Risk Management Assets	(562,000,000)	[10],[9]			(562,000,000)	[10],[9]			(1,013,000,000)	[11],[9]
Liabilities:
Risk Management Liabilities	(592,000,000)	[10],[9]			(592,000,000)	[10],[9]			(1,114,000,000)	[11],[9]
Commodity Hedges [Member]
Risk Management Assets
Risk Management Assets	23,000,000	[9]			23,000,000	[9]			13,000,000	[9]
Liabilities:
Risk Management Liabilities	4,000,000	[9]			4,000,000	[9]			2,000,000	[9]
Commodity Hedges [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	11,000,000	[9]			11,000,000	[9]			11,000,000	[9]
Liabilities:
Risk Management Liabilities	1,000,000	[9]			1,000,000	[9]			4,000,000	[9]
Commodity Hedges [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	24,000,000	[9]			24,000,000	[9]			17,000,000	[9]
Liabilities:
Risk Management Liabilities	15,000,000	[9]			15,000,000	[9]			13,000,000	[9]
Commodity Hedges [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	0	[9]			0	[9]			0	[9]
Liabilities:
Risk Management Liabilities	0	[9]			0	[9]			0	[9]
Commodity Hedges [Member] | Fair Value Inputs Other [Member]
Risk Management Assets
Risk Management Assets	(12,000,000)	[9]			(12,000,000)	[9]			(15,000,000)	[9]
Liabilities:
Risk Management Liabilities	(12,000,000)	[9]			(12,000,000)	[9]			(15,000,000)	[9]
Interest Rate Foreign Currency Hedges [Member]
Risk Management Assets
Risk Management Assets	0				0				25,000,000
Liabilities:
Risk Management Liabilities	34,000,000				34,000,000				4,000,000
Interest Rate Foreign Currency Hedges [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	0				0				0
Liabilities:
Risk Management Liabilities	0				0				0
Interest Rate Foreign Currency Hedges [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	0				0				25,000,000
Liabilities:
Risk Management Liabilities	34,000,000				34,000,000				4,000,000
Interest Rate Foreign Currency Hedges [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	0				0				0
Liabilities:
Risk Management Liabilities	0				0				0
Interest Rate Foreign Currency Hedges [Member] | Fair Value Inputs Other [Member]
Risk Management Assets
Risk Management Assets	0				0				0
Liabilities:
Risk Management Liabilities	0				0				0
Fair Value Hedges [Member]
Risk Management Assets
Risk Management Assets	0				0				7,000,000
Liabilities:
Risk Management Liabilities									1,000,000
Fair Value Hedges [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	0				0				0
Liabilities:
Risk Management Liabilities									0
Fair Value Hedges [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	0				0				7,000,000
Liabilities:
Risk Management Liabilities									1,000,000
Fair Value Hedges [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	0				0				0
Liabilities:
Risk Management Liabilities									0
Fair Value Hedges [Member] | Fair Value Inputs Other [Member]
Risk Management Assets
Risk Management Assets	0				0				0
Liabilities:
Risk Management Liabilities									0
2011 [Member] | Level 1 [Member]
Fair Value Measurements (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities	0				0				(2,000,000)
2011 [Member] | Level 2 [Member]
Fair Value Measurements (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities	3,000,000				3,000,000				13,000,000
2011 [Member] | Level 3 [Member]
Fair Value Measurements (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities	5,000,000				5,000,000				18,000,000
2012 - 2014 [Member] | Level 1 [Member]
Fair Value Measurements (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities	6,000,000				6,000,000				2,000,000
2012 - 2014 [Member] | Level 2 [Member]
Fair Value Measurements (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities	80,000,000				80,000,000				66,000,000
2012 - 2014 [Member] | Level 3 [Member]
Fair Value Measurements (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities	17,000,000				17,000,000				24,000,000
2015 - 2016 [Member] | Level 2 [Member]
Fair Value Measurements (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities	22,000,000				22,000,000				12,000,000
2015 - 2016 [Member] | Level 3 [Member]
Fair Value Measurements (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities	13,000,000				13,000,000				16,000,000
2015 - 2018 [Member] | Level 1 [Member]
Fair Value Measurements (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities	0				0				(5,000,000)
2017 - 2028 [Member] | Level 2 [Member]
Fair Value Measurements (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities	16,000,000				16,000,000				16,000,000
2017 - 2028 [Member] | Level 3 [Member]
Fair Value Measurements (Textuals) [Abstract]
Maturity of Net Fair Value of Risk Management Contracts Prior to Cash Collateral, Assets/Liabilities	29,000,000				29,000,000				27,000,000
Within 1 Year [Member]
Nuclear trust fund investments
Estimated Fair Value	79,000,000				79,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	79,000,000				79,000,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	79,000,000				79,000,000
1 year - 5 years [Member]
Nuclear trust fund investments
Estimated Fair Value	269,000,000				269,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	269,000,000				269,000,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	269,000,000				269,000,000
5 years - 10 years [Member]
Nuclear trust fund investments
Estimated Fair Value	318,000,000				318,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	318,000,000				318,000,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	318,000,000				318,000,000
After 10 years [Member]
Nuclear trust fund investments
Estimated Fair Value	257,000,000				257,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	257,000,000				257,000,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	257,000,000				257,000,000
Cash [Member]
Other Temporary Investments
Cost	164,000,000	[12]			164,000,000	[12]			225,000,000	[12]
Gross Unrealized Gains	0				0				0
Gross Unrealized Losses	0				0				0
Assets:
Total Other Temporary Investments	164,000,000	[1]			164,000,000	[1]			225,000,000	[1]
Cash [Member] | Level 1 [Member]
Assets:
Total Other Temporary Investments	123,000,000	[1]			123,000,000	[1]			184,000,000	[1]
Cash [Member] | Level 2 [Member]
Assets:
Total Other Temporary Investments	0	[1]			0	[1]			0	[1]
Cash [Member] | Level 3 [Member]
Assets:
Total Other Temporary Investments	0	[1]			0	[1]			0	[1]
Cash [Member] | Fair Value Inputs Other [Member]
Assets:
Total Other Temporary Investments	41,000,000	[1]			41,000,000	[1]			41,000,000	[1]
Fixed Income Funds [Member]
Nuclear trust fund investments
Gross Unrealized Gains	64,000,000				64,000,000				26,000,000
Other-Than-Temporary Impairments	(4,000,000)				(4,000,000)				(3,000,000)
Mutual Funds Fixed Income [Member]
Other Temporary Investments
Cost	63,000,000				63,000,000				69,000,000
Gross Unrealized Gains	0				0				0
Gross Unrealized Losses	0				0				0
Assets:
Total Other Temporary Investments	63,000,000				63,000,000				69,000,000
Mutual Funds Fixed Income [Member] | Level 1 [Member]
Assets:
Total Other Temporary Investments	63,000,000				63,000,000				69,000,000
Mutual Funds Fixed Income [Member] | Level 2 [Member]
Assets:
Total Other Temporary Investments	0				0				0
Mutual Funds Fixed Income [Member] | Level 3 [Member]
Assets:
Total Other Temporary Investments	0				0				0
Mutual Funds Fixed Income [Member] | Fair Value Inputs Other [Member]
Assets:
Total Other Temporary Investments	0				0				0
Variable Rate Demand Notes [Member]
Other Temporary Investments
Cost	0				0				97,000,000
Gross Unrealized Gains	0				0				0
Gross Unrealized Losses	0				0				0
Assets:
Total Other Temporary Investments	0				0				97,000,000
Variable Rate Demand Notes [Member] | Level 1 [Member]
Assets:
Total Other Temporary Investments	0				0				0
Variable Rate Demand Notes [Member] | Level 2 [Member]
Assets:
Total Other Temporary Investments	0				0				97,000,000
Variable Rate Demand Notes [Member] | Level 3 [Member]
Assets:
Total Other Temporary Investments	0				0				0
Variable Rate Demand Notes [Member] | Fair Value Inputs Other [Member]
Assets:
Total Other Temporary Investments	0				0				0
Equity Securities - Domestic [Member]
Nuclear trust fund investments
Estimated Fair Value									634,000,000	[13]
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities									634,000,000	[13]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts									634,000,000	[13]
Equity Securities - Domestic [Member] | Level 1 [Member]
Nuclear trust fund investments
Estimated Fair Value									634,000,000	[13]
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities									634,000,000	[13]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts									634,000,000	[13]
Domestic [Member]
Nuclear trust fund investments
Estimated Fair Value	576,000,000	[13]			576,000,000	[13]
Gross Unrealized Gains	144,000,000				144,000,000				183,000,000
Other-Than-Temporary Impairments	(84,000,000)				(84,000,000)				(123,000,000)
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	576,000,000	[13]			576,000,000	[13]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	576,000,000	[13]			576,000,000	[13]
Domestic [Member] | Level 1 [Member]
Nuclear trust fund investments
Estimated Fair Value	576,000,000	[13]			576,000,000	[13]
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	576,000,000	[13]			576,000,000	[13]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	576,000,000	[13]			576,000,000	[13]
Domestic [Member] | Level 2 [Member]
Nuclear trust fund investments
Estimated Fair Value	0	[13]			0	[13]			0	[13]
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	0	[13]			0	[13]			0	[13]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	[13]			0	[13]			0	[13]
Domestic [Member] | Level 3 [Member]
Nuclear trust fund investments
Estimated Fair Value	0	[13]			0	[13]			0	[13]
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	0	[13]			0	[13]			0	[13]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	[13]			0	[13]			0	[13]
Domestic [Member] | Fair Value Inputs Other [Member]
Nuclear trust fund investments
Estimated Fair Value	0	[13]			0	[13]			0	[13]
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	0	[13]			0	[13]			0	[13]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	[13]			0	[13]			0	[13]
Mutual Funds Equity [Member]
Other Temporary Investments
Cost	11,000,000				11,000,000				18,000,000
Gross Unrealized Gains	2,000,000				2,000,000				7,000,000
Gross Unrealized Losses	0				0				0
Assets:
Total Other Temporary Investments	13,000,000	[13]			13,000,000	[13]			25,000,000	[13]
Mutual Funds Equity [Member] | Level 1 [Member]
Assets:
Total Other Temporary Investments	13,000,000	[13]			13,000,000	[13]			25,000,000	[13]
Mutual Funds Equity [Member] | Level 2 [Member]
Assets:
Total Other Temporary Investments	0	[13]			0	[13]			0	[13]
Mutual Funds Equity [Member] | Level 3 [Member]
Assets:
Total Other Temporary Investments	0	[13]			0	[13]			0	[13]
Mutual Funds Equity [Member] | Fair Value Inputs Other [Member]
Assets:
Total Other Temporary Investments	0	[13]			0	[13]			0	[13]
Cash and Cash Equivalents [Member]
Nuclear trust fund investments
Estimated Fair Value	14,000,000	[14]			14,000,000	[14]			20,000,000	[14]
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	14,000,000	[14]			14,000,000	[14]			20,000,000	[14]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	14,000,000	[14]			14,000,000	[14]			20,000,000	[14]
Cash and Cash Equivalents [Member] | Level 1 [Member]
Nuclear trust fund investments
Estimated Fair Value	0	[14]			0	[14]			0	[14]
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	0	[14]			0	[14]			0	[14]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	[14]			0	[14]			0	[14]
Cash and Cash Equivalents [Member] | Level 2 [Member]
Nuclear trust fund investments
Estimated Fair Value	5,000,000	[14]			5,000,000	[14]			8,000,000	[14]
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	5,000,000	[14]			5,000,000	[14]			8,000,000	[14]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	5,000,000	[14]			5,000,000	[14]			8,000,000	[14]
Cash and Cash Equivalents [Member] | Level 3 [Member]
Nuclear trust fund investments
Estimated Fair Value	0	[14]	0	[14]	0	[14]	0	[14]
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	0	[14]	0	[14]	0	[14]	0	[14]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0	[14]	0	[14]	0	[14]	0	[14]
Cash and Cash Equivalents [Member] | Fair Value Inputs Other [Member]
Nuclear trust fund investments
Estimated Fair Value	9,000,000	[14]			9,000,000	[14]			12,000,000	[14]
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	9,000,000	[14]			9,000,000	[14]			12,000,000	[14]
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	9,000,000	[14]			9,000,000	[14]			12,000,000	[14]
US Government Agencies Debt Securities [Member]
Nuclear trust fund investments
Estimated Fair Value	550,000,000				550,000,000				461,000,000
Gross Unrealized Gains	59,000,000				59,000,000				23,000,000
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	550,000,000				550,000,000				461,000,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	550,000,000				550,000,000				461,000,000
US Government Agencies Debt Securities [Member] | Level 1 [Member]
Nuclear trust fund investments
Estimated Fair Value	0				0				0
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	0				0				0
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0				0				0
US Government Agencies Debt Securities [Member] | Level 2 [Member]
Nuclear trust fund investments
Estimated Fair Value	550,000,000				550,000,000				461,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	550,000,000				550,000,000				461,000,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	550,000,000				550,000,000				461,000,000
US Government Agencies Debt Securities [Member] | Level 3 [Member]
Nuclear trust fund investments
Estimated Fair Value	0				0				0
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	0				0				0
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]
Nuclear trust fund investments
Estimated Fair Value	0				0				0
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	0				0				0
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0				0				0
Corporate Debt [Member]
Nuclear trust fund investments
Estimated Fair Value	53,000,000				53,000,000				59,000,000
Gross Unrealized Gains	5,000,000				5,000,000				4,000,000
Other-Than-Temporary Impairments	(2,000,000)				(2,000,000)				(2,000,000)
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	53,000,000				53,000,000				59,000,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	53,000,000				53,000,000				59,000,000
Corporate Debt [Member] | Level 1 [Member]
Nuclear trust fund investments
Estimated Fair Value	0				0				0
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	0				0				0
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0				0				0
Corporate Debt [Member] | Level 2 [Member]
Nuclear trust fund investments
Estimated Fair Value	53,000,000				53,000,000				59,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	53,000,000				53,000,000				59,000,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	53,000,000				53,000,000				59,000,000
Corporate Debt [Member] | Level 3 [Member]
Nuclear trust fund investments
Estimated Fair Value	0				0				0
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	0				0				0
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0				0				0
Corporate Debt [Member] | Fair Value Inputs Other [Member]
Nuclear trust fund investments
Estimated Fair Value	0				0				0
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	0				0				0
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0				0				0
State and Local Jurisdiction [Member]
Nuclear trust fund investments
Estimated Fair Value	320,000,000				320,000,000				341,000,000
Gross Unrealized Gains	0				0				(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	320,000,000				320,000,000				341,000,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	320,000,000				320,000,000				341,000,000
State and Local Jurisdiction [Member] | Level 1 [Member]
Nuclear trust fund investments
Estimated Fair Value	0				0				0
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	0				0				0
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0				0				0
State and Local Jurisdiction [Member] | Level 2 [Member]
Nuclear trust fund investments
Estimated Fair Value	320,000,000				320,000,000				341,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	320,000,000				320,000,000				341,000,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	320,000,000				320,000,000				341,000,000
State and Local Jurisdiction [Member] | Level 3 [Member]
Nuclear trust fund investments
Estimated Fair Value	0				0				0
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	0				0				0
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]
Nuclear trust fund investments
Estimated Fair Value	0				0				0
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	0				0				0
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0				0				0
Dedesignated Risk Management Contracts [Member]
Risk Management Assets
Risk Management Assets	34,000,000	[15]			34,000,000	[15]			46,000,000	[15]
Dedesignated Risk Management Contracts [Member] | Level 1 [Member]
Risk Management Assets
Risk Management Assets	0	[15]			0	[15]			0	[15]
Dedesignated Risk Management Contracts [Member] | Level 2 [Member]
Risk Management Assets
Risk Management Assets	0	[15]			0	[15]			0	[15]
Dedesignated Risk Management Contracts [Member] | Level 3 [Member]
Risk Management Assets
Risk Management Assets	0	[15]			0	[15]			0	[15]
Dedesignated Risk Management Contracts [Member] | Fair Value Inputs Other [Member]
Risk Management Assets
Risk Management Assets	34,000,000	[15]			34,000,000	[15]			46,000,000	[15]
Other Temporary Investments [Member]
Other Temporary Investments
Cost	238,000,000				238,000,000				409,000,000
Gross Unrealized Gains	2,000,000				2,000,000				7,000,000
Gross Unrealized Losses	0				0				0
Level 1 [Member]
Nuclear trust fund investments
Estimated Fair Value	576,000,000				576,000,000				634,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	576,000,000				576,000,000				634,000,000
Assets:
Cash and Cash Equivalents	13,000,000	[1]			13,000,000	[1]			170,000,000	[1]
Total Other Temporary Investments	199,000,000				199,000,000				278,000,000
Risk Management Assets
Risk Management Assets	36,000,000				36,000,000				31,000,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	576,000,000				576,000,000				634,000,000
Total Assets	824,000,000				824,000,000				1,113,000,000
Liabilities:
Risk Management Liabilities	26,000,000				26,000,000				29,000,000
Level 2 [Member]
Nuclear trust fund investments
Estimated Fair Value	928,000,000				928,000,000				869,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	928,000,000				928,000,000				869,000,000
Assets:
Cash and Cash Equivalents	0	[1]			0	[1]			0	[1]
Total Other Temporary Investments	0				0				97,000,000
Risk Management Assets
Risk Management Assets	879,000,000				879,000,000				1,481,000,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	928,000,000				928,000,000				869,000,000
Total Assets	1,807,000,000				1,807,000,000				2,447,000,000
Liabilities:
Risk Management Liabilities	783,000,000				783,000,000				1,343,000,000
Level 3 [Member]
Nuclear trust fund investments
Estimated Fair Value	0				0				0
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	0				0				0
Assets:
Cash and Cash Equivalents	0	[1]			0	[1]			0	[1]
Total Other Temporary Investments	0				0				0
Risk Management Assets
Risk Management Assets	105,000,000				105,000,000				112,000,000
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	0				0				0
Total Assets	105,000,000				105,000,000				112,000,000
Liabilities:
Risk Management Liabilities	41,000,000				41,000,000				27,000,000
Fair Value Inputs Other [Member]
Nuclear trust fund investments
Estimated Fair Value	9,000,000				9,000,000				12,000,000
Contractual Maturities, Fair Value of Debt Securities
Contractual Maturities, Fair Value of Debt Securities	9,000,000				9,000,000				12,000,000
Assets:
Cash and Cash Equivalents	533,000,000	[1]			533,000,000	[1]			124,000,000	[1]
Total Other Temporary Investments	41,000,000				41,000,000				41,000,000
Risk Management Assets
Risk Management Assets	(540,000,000)				(540,000,000)				(982,000,000)
Spent Nuclear Fuel and Decommissioning Trusts
Spent Nuclear Fuel and Decommissioning Trusts	9,000,000				9,000,000				12,000,000
Total Assets	43,000,000				43,000,000				(805,000,000)
Liabilities:
Risk Management Liabilities	$ (604,000,000)				$ (604,000,000)				$ (1,129,000,000)

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

[2] Included in revenues on our 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 our condensed statements of income. These net gains (losses) are recorded as regulatory liabilities/assets

[9] 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.''

[10] The September 30, 2011 maturity of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), is as follows: Level 1 matures $0 in 2011, $6 million in periods 2012-2014 and ($6) million in periods 2015-2016; Level 2 matures $3 million in 2011, $80 million in periods 2012-2014, $22 million in periods 2015-2016 and $16 million in periods 2017-2028; Level 3 matures $5 million in 2011, $17 million in periods 2012-2014, $13 million in periods 2015-2016 and $29 million in periods 2017-2028. Risk management commodity contracts are substantially comprised of power contracts.

[11] The December 31, 2010 maturity of the net fair value of risk management contracts prior to cash collateral, assets/(liabilities), is as follows: Level 1 matures ($2) million in 2011, $2 million in periods 2012-2014 and ($5) million in periods 2015-2018; Level 2 matures $13 million in 2011, $66 million in periods 2012-2014, $12 million in periods 2015-2016 and $16 million in periods 2017-2028; Level 3 matures $18 million in 2011, $24 million in periods 2012-2014, $16 million in periods 2015-2016 and $27 million in periods 2017-2028. Risk management commodity contracts are substantially comprised of power contracts.

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

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

[14] Amounts in ''Other'' column primarily represent accrued interest receivables from financial institutions. Level 2 amounts primarily represent investments in money market funds.

[15] Represents contracts that were originally MTM but were subsequently elected as normal under the accounting guidance for ''Derivatives and Hedging.'' At the time of the normal election, the MTM value was frozen and no longer fair valued. This MTM value will be amortized into revenues over the remaining life of the contracts.