Debtor-In-Possession Borrowing Facility and Long-Term Debt Not Subject to Compromise - TCEH Debtor-In-Possession Facility (Details)		9 Months Ended
		Sep. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)
Line of Credit Facility [Line Items]
Borrowings under debtor-in-possession credit facility (Note 8)		$ 0	$ 1,425,000,000
Consolidated Superpriority Secured Net Debt to Consolidated EBITDA Covenant Threshold		3.50
Texas Competitive Electric Holdings Company LLC | Debtor-In-Possession Facility [Member]
Line of Credit Facility [Line Items]
Debtor-In-Possession Financing, Extension Fee		$ 8,000,000
Facility Limit		3,375,000,000
Available Cash Borrowing Capacity		1,950,000,000
Available Letter of Credit Capacity		$ 436,000,000
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum		0.75%
Debt Instrument, Basis Spread on Variable Rate		3.00%
Debtor-in-Possession Financing, Interest Rate on Borrowings Outstanding		3.75%
Texas Competitive Electric Holdings Company LLC | Debtor-In-Possession Facility [Member] | Senior Secured Super-Priority Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Facility Limit	[1]	$ 1,950,000,000
Available Cash Borrowing Capacity	[1]	1,950,000,000
Available Letter of Credit Capacity	[1]	0
Borrowings under debtor-in-possession credit facility (Note 8)		0
Debtor-In-Possession Financing, Maximum Borrowings Allowed Without Consent Or Bankruptcy Court Order		1,650,000,000
Texas Competitive Electric Holdings Company LLC | Debtor-In-Possession Facility [Member] | Senior Secured Super-Priority Term Loan [Member]
Line of Credit Facility [Line Items]
Facility Limit	[2]	1,425,000,000
Available Cash Borrowing Capacity	[2]	0
Available Letter of Credit Capacity	[2]	436,000,000
Borrowings under debtor-in-possession credit facility (Note 8)		1,425,000,000	$ 1,425,000,000
Debtor-In-Possession Financing, Amount Arranged, Maximum Letter of Credit Capacity		800,000,000
Debtor-In-Possession Financing, Collateral Account, Total Amount Held To Support Letters Of Credit		800,000,000
Texas Competitive Electric Holdings Company LLC | Debtor-In-Possession Facility [Member] | Senior Secured Super-Priority Term Loan [Member] | Cash and Cash Equivalents [Member]
Line of Credit Facility [Line Items]
Debtor-In-Possession Financing, Collateral Account, Total Amount Held To Support Letters Of Credit		436,000,000
Texas Competitive Electric Holdings Company LLC | Debtor-In-Possession Facility [Member] | Senior Secured Super-Priority Term Loan [Member] | Restricted Cash [Member]
Line of Credit Facility [Line Items]
Debtor-In-Possession Financing, Collateral Account, Total Amount Held To Support Letters Of Credit		364,000,000
Railroad Commission of Texas [Member] | Texas Competitive Electric Holdings Company LLC
Line of Credit Facility [Line Items]
Collateral Bond, Securing Mining Land Reclamation Obligations, Secured By First Lien Interest In Assets		$ 1,100,000,000

[1] Facility used for general corporate purposes. No amounts were borrowed at September 30, 2015. Pursuant to an order of the Bankruptcy Court, the TCEH Debtors may not have more than $1.650 billion of TCEH DIP Revolving Credit Facility cash borrowings outstanding without written consent of the TCEH committee of unsecured creditors and the ad hoc group of TCEH unsecured noteholders or further order of the Bankruptcy Court.

[2] Facility used for general corporate purposes, including but not limited to, $800 million for issuing letters of credit.