Commodity And Other Derivative Contractual Assets And Liabilities (Derivative Assets and Liabilities From Balance Sheet to Net Amounts After Consideration Netting Arrangements with Counterparties and Financial Collateral) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
Derivatives, Fair Value [Line Items]
Derivative Assets (Liability), Fair Value, Amount Offset Against Collateral, Secured By First Lien Interest in Subsidiary	$ 1,200,000,000
Derivative assets: Amounts Presented in Balance Sheet	1,132,000,000		2,049,000,000
Derivative assets: Offsetting Financial Instruments	(614,000,000)	[1]	(1,265,000,000)	[1]
Derivative assets: Financial Collateral (Received) Pledged	(351,000,000)	[2]	(597,000,000)	[2]
Derivative assets: Net Amounts	167,000,000	[3]	187,000,000
Derivative liabilities: Amounts Presented in Balance Sheet	(1,376,000,000)		(2,450,000,000)
Derivative liabilities: Offsetting Financial Instruments	614,000,000	[1]	1,265,000,000	[1]
Derivative liabilities: Financial Collateral (Received) Pledged	11,000,000	[2]	29,000,000	[2]
Derivative liabilities: Net Amounts	(751,000,000)	[3]	(1,156,000,000)
Derivative, Fair Value, Net	(244,000,000)		(401,000,000)
Derivative Asset (Liabilit), Collateral, Obligation to Return Cash	0		0
Derivative (Assets) Liability, Fair Value of Collateral, Net	340,000,000	[2]	568,000,000	[2]
Derivative Assets (Liability), Fair Value, Amount Offset Against Collateral	(584,000,000)	[3]	(969,000,000)
Commodity contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative assets: Amounts Presented in Balance Sheet	1,131,000,000		2,047,000,000
Derivative assets: Offsetting Financial Instruments	(613,000,000)	[1]	(1,263,000,000)	[1]
Derivative assets: Financial Collateral (Received) Pledged	(351,000,000)	[2]	(597,000,000)	[2]
Derivative assets: Net Amounts	167,000,000	[3]	187,000,000
Derivative liabilities: Amounts Presented in Balance Sheet	(209,000,000)		(383,000,000)
Derivative liabilities: Offsetting Financial Instruments	180,000,000	[1]	319,000,000	[1]
Derivative liabilities: Financial Collateral (Received) Pledged	11,000,000	[2]	29,000,000	[2]
Derivative liabilities: Net Amounts	(18,000,000)	[3]	(35,000,000)
Interest rate swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative assets: Amounts Presented in Balance Sheet	1,000,000		2,000,000
Derivative assets: Offsetting Financial Instruments	(1,000,000)	[1]	(2,000,000)	[1]
Derivative assets: Financial Collateral (Received) Pledged	0	[2]	0	[2]
Derivative assets: Net Amounts	0	[3]	0
Derivative liabilities: Amounts Presented in Balance Sheet	(1,167,000,000)		(2,067,000,000)
Derivative liabilities: Offsetting Financial Instruments	434,000,000	[1]	946,000,000	[1]
Derivative liabilities: Financial Collateral (Received) Pledged	0	[2]	0	[2]
Derivative liabilities: Net Amounts	$ (733,000,000)	[3]	$ (1,121,000,000)

[1] xclude trade accounts receivable and payable related to settled financial instruments.

[2] Financial collateral consists entirely of cash margin deposits.

[3] Includes net liability positions totaling approximately $1.2 billion (before nonperformance risk adjustment) related to counterparties with positions that are secured by a first-lien interest in the same assets of TCEH (on a pari passu basis) with the TCEH Senior Secured Facilities and the TCEH Senior Secured Notes.