Debtor-in-Possession Facility (Details) - USD ($) $ in Millions	1 Months Ended				8 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2015	Mar. 31, 2015	Jun. 30, 2014	Jan. 31, 2013	Dec. 31, 2014	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Line of Credit Facility [Line Items]
Debtor-in-Possession Financing, Borrowings Outstanding	$ 0				$ 5,400		$ 0	$ 5,400
Pre-Petition Interest Paid and Accrued On Pre-Petition Debt							57	128	$ 0
Debtor-In-Possession Financing, Borrowings Issued And Held As Cash	354				1,157		354	1,157	242	$ 424
Debtor Reorganization Items, Gain (Loss) On Exchange And Settlement Of Debt Instruments					$ 108		0	$ 108	$ 0
Energy Future Intermediate Holding Co LLC [Member]
Line of Credit Facility [Line Items]
Debtor-In-Possession Financing, Borrowings Issued And Held As Cash	354						354
Debtor-In-Possession Financing, Extension Fee							$ 14
First-Lien Debtor-in-Possession Facility [Member] \| Energy Future Intermediate Holding Co LLC [Member]
Line of Credit Facility [Line Items]
Debtor-In-Possession Financing, Extension Fee, Twenty-Fifth Through Thirtieth Month							0.25%
Debtor-In-Possession Financing, Incremental Junior Lien Debt Allowed, Maximum							$ 3,000
First-Lien Debtor-in-Possession Facility [Member] \| Senior Secured Super-Priority First Lien Term Loan [Member] \| Energy Future Intermediate Holding Co LLC [Member]
Line of Credit Facility [Line Items]
Debtor In Possession Financing, Liquidity Covenant, Unrestricted Cash Balance, Minimum	150						150
Debtor-in-Possession Financing, Borrowings Outstanding	$ 5,400						$ 5,400
Debtor-in-Possession Financing, Interest Rate on Borrowings Outstanding	4.25%						4.25%
Debtor-In-Possession Financing, Borrowings Used to Repay Pre-Petition Debt			$ 2,438
Debtor-in-Possession Financing, Amount Arranged	$ 5,400						$ 5,400
Debtor-In-Possession Financing, Borrowings Used In Exchange Transaction For Pre-Petition Debt			1,836
Debtor Reorganization Items, Gain (Loss) On Exchange And Settlement Of Debt Instruments							$ 108
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum							1.00%
Debt Instrument, Basis Spread on Variable Rate							3.25%
Secured Debt [Member] \| Energy Future Intermediate Holding Co LLC [Member]
Line of Credit Facility [Line Items]
Principal Amount Of Affiliate Debt Acquired In Exchange Transaction				$ 1,310
Secured Debt [Member] \| Fixed Senior Secured First Lien 6.875% Notes and Fixed Senior Secured First Lien 10% Notes [Member] \| Energy Future Intermediate Holding Co LLC [Member]
Line of Credit Facility [Line Items]
Principal Amount Of Affiliate Debt Repurchased			2,312
Principal Amount Of Affiliate Debt Acquired In Exchange Transaction			$ 1,673
Secured Debt [Member] \| Fixed Senior Secured Second Lien 11% Notes and Fixed Senior Secured Second Lien 11.75% Notes [Member] [Member] \| Energy Future Intermediate Holding Co LLC [Member]
Line of Credit Facility [Line Items]
Repayment of Debt And Pre-Petition And Post-Petition Interest		$ 750
Repayments of Debt		445
Pre-Petition Interest Paid and Accrued On Pre-Petition Debt	2	55
Pre and Post-Petition Interest Paid And Accrued On Pre-Petition Debt		$ 235				$ 235
Senior Notes [Member] \| Energy Future Intermediate Holding Co LLC [Member]
Line of Credit Facility [Line Items]
Principal Amount Of Affiliate Debt Acquired In Exchange Transaction				$ 95
Senior Notes [Member] \| 11.25%/12.25% Senior Toggle Notes due December 1, 2018 [Member] \| Energy Future Intermediate Holding Co LLC [Member]
Line of Credit Facility [Line Items]
Repayments of Debt	$ 36
RSA First Lien Note Parties And Qualifying Holders of EFIH First Lien Notes Tendered By Participation Date [Member] \| First-Lien Debtor-in-Possession Facility [Member] \| Debtor-in-Possession Financing, First Lien Debt Facility Agreement [Member] \| Energy Future Intermediate Holding Co LLC [Member]
Line of Credit Facility [Line Items]
Debtor-in-Possession Financing, Debt Settlement, Settlement Price, Percentage of Principal and Percentage of Accrued and Unpaid Interest, Percentage of Accrued and Unpaid Interest			101.00%
Debtor-in-Possession Financing, Debt Settlement, Settlement Price, Percentage of Principal and Percentage of Accrued and Unpaid Interest, Percentage of Principal			105.00%
RSA First Lien Note Parties And Qualifying Holders of EFIH First Lien Notes Tendered By Participation Date [Member] \| Secured Debt [Member] \| Fixed Senior Secured First Lien 6.875% Notes and Fixed Senior Secured First Lien 10% Notes [Member] \| Energy Future Intermediate Holding Co LLC [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Increase, Accrued Interest			$ 78
Non-Settling Holders Of EFIH First Lien Notes [Member] \| Secured Debt [Member] \| Fixed Senior Secured First Lien 6.875% Notes and Fixed Senior Secured First Lien 10% Notes [Member] \| Energy Future Intermediate Holding Co LLC [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Increase, Accrued Interest			$ 128

Energy Future Intermediate Holding CO LLC 10-K