Supplementary Financial Information (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended				1 Months Ended															1 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Jan. 31, 2013 Secured Debt [Member]	Jan. 31, 2013 Secured Debt [Member] Energy Future Holdings Corp. [Member]	Jun. 30, 2014 Senior Secured Super-Priority First Lien Term Loan [Member] First-Lien Debtor-in-Possession Facility [Member] Energy Future Intermediate Holding CO LLC [Member]	Jun. 30, 2014 Fixed Senior Secured First Lien 6.875% Notes and Fixed Senior Secured First Lien 10% Notes [Member] Secured Debt [Member] Energy Future Intermediate Holding CO LLC [Member]	Jan. 31, 2013 10% Fixed Senior Secured First Lien Notes due December 1, 2020 [Member] Secured Debt [Member]	Sep. 30, 2014 Energy Future Holdings Corp. [Member] Push Down Debt [Member]	Sep. 30, 2013 Energy Future Holdings Corp. [Member] Push Down Debt [Member]	Sep. 30, 2014 Reported Value Measurement [Member] Debtor-In-Possession Facility [Member]	Dec. 31, 2013 Reported Value Measurement [Member] Debtor-In-Possession Facility [Member]	Sep. 30, 2014 Reported Value Measurement [Member] Pre-Petition Notes, Loans And Other Debt (Excluding Capital Leases) [Member]	Dec. 31, 2013 Reported Value Measurement [Member] Pre-Petition Notes, Loans And Other Debt (Excluding Capital Leases) [Member]	Sep. 30, 2014 Fair Value, Inputs, Level 2 [Member] Estimate of Fair Value Measurement [Member] Debtor-In-Possession Facility [Member]	Dec. 31, 2013 Fair Value, Inputs, Level 2 [Member] Estimate of Fair Value Measurement [Member] Debtor-In-Possession Facility [Member]	Sep. 30, 2014 Fair Value, Inputs, Level 2 [Member] Estimate of Fair Value Measurement [Member] Pre-Petition Notes, Loans And Other Debt (Excluding Capital Leases) [Member]	Dec. 31, 2013 Fair Value, Inputs, Level 2 [Member] Estimate of Fair Value Measurement [Member] Pre-Petition Notes, Loans And Other Debt (Excluding Capital Leases) [Member]	Jun. 30, 2014 RSA First Lien Note Parties And Qualifying Holders of EFIH First Lien Notes Tendered By Participation Date [Member] Fixed Senior Secured First Lien 6.875% Notes and Fixed Senior Secured First Lien 10% Notes [Member] Secured Debt [Member] Energy Future Intermediate Holding CO LLC [Member]
Schedule of Held-to-maturity Securities And Available For Sale Securities [Line Items]
Debt Instrument, Fair Value Disclosure												$ 5,400	$ 0	$ 3,876	$ 7,877	$ 5,380	$ 0	$ 4,387	$ 7,849
Cash payments related to:
Interest on EFIH debt	316		423
Income taxes	0		3
Reorganization Payments For Legal And Other Consulting Services	19	[1]	0
Noncash investing and financing activities:
Principal amount of toggle notes issued in lieu of cash interest	0		83
Parent's payment of interest on pushed-down debt accounted for as a contribution of capital (Note 7)	0		21
Reduction of debt pushed down from EFH Corp. (b)	0		(420)	[2]
Debt exchange transactions (c)	(85)	[3]	14	[3]
Distribution to EFH Corp. of debt held as investment	0		(5,778)
Principal Amount Of Affiliate Debt Given In Exchange Transaction			838
Percentage of principal plus unamortized premium of related party Merger-related debt guaranteed by parent company (as a percent)										50.00%	50.00%
Debtor-In-Possession Financing, Borrowings Used In Exchange Transaction For Pre-Petition Debt							1,836
Long Term Debt And Capital Leases Issued, Principal Amount					89				1,302
Principal Amount Of Affiliate Debt Acquired In Exchange Transaction					1,310	95		1,673
Debt Instrument, Increase, Accrued Interest																				78
Deferred Tax On Interest Received On Holdings Of Long Term Debt Of Affiliates	$ 0		$ 73

[1] Represents cash payments for legal and other consulting services.

[2] For the nine months ended September 30, 2013, represents $838 million principal amount of EFH Corp. debt exchanged (at 50%) for EFIH debt.

[3] or the nine months ended September 30, 2014, represents $1.836 billion principal amount of loans issued under the EFIH DIP Facility in excess of $1.673 billion principal amount of EFIH First Lien Notes exchanged and $78 million of related accrued interest (see Note 5). For the nine months ended September 30, 2013 represents $1.302 billion principal amount of EFIH debt issued in exchange for $1.310 billion principal amount of EFH Corp. and EFIH debt and $89 million principal amount of EFIH debt issued in exchange for $95 million principal amount of EFH Corp. debt.