Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

Accounting Policies [Abstract]

Public Utilities General Disclosures [Table Text Block]

Houston Electric recorded the following:

	Year Ended December 31,
	2017		2016		2015
	(in millions)
Capitalized interest and AFUDC included in Interest and other finance charges	$	6	$	6	$	8
AFUDC equity included in Other Income	10		6		12

Restrictions on Cash and Cash Equivalents [Table Text Block]

In connection with the issuance of Securitization Bonds, Houston Electric was required to establish restricted cash accounts to collateralize the bonds that were issued in these financing transactions. These restricted cash accounts are not available for withdrawal until the maturity of the bonds and are not included in cash and cash equivalents. Restricted cash accounts as of December 31, 2017 and 2016 are reported below.

	December 31,
	2017		2016
	(in millions)
Restricted cash included in Other current assets	$	35	$	40
Restricted cash included in Other assets	1		—
Total restricted cash	$	36	$	40