Long-term Debt (Tables)

12 Months Ended

Dec. 31, 2015

Debt Disclosure [Abstract]

Schedule of Debt [Table Text Block]

	December 31, 2015					December 31, 2014
	Long-Term			Current (1)		Long-Term			Current (1)
	(in millions)
Long-term debt:
Bank Loans	$	200		$	—	$	—		$	—
First mortgage bonds 9.15% due 2021	102			—		102			—
General mortgage bonds 2.25% to 6.95% due 2022 to 2044 (2)	1,912			—		1,912			—
System restoration bonds 3.46% to 4.243% due 2018 to 2022	365			50		415			48
Transition bonds 0.901% to 5.302% due 2017 to 2024	1,918			341		2,259			324
Other	(8		)	—		(8		)	—
Total long-term debt	$	4,489		$	391	$	4,680		$	372

(1) Includes amounts due or scheduled to be paid within one year of the date noted.

(2) Debt issued as collateral is excluded from the financial statements because of the contingent nature of the obligation.

Schedule of Line of Credit Facilities [Table Text Block]

Revolving Credit Facility. As of December 31, 2015 and 2014, CenterPoint Houston had the following revolving credit facility and utilization of such facility:

December 31, 2015							December 31, 2014
Size of Facility		Loans			Letters of Credit		Size of Facility		Loans		Letters of Credit
(in millions)
$	300	$	200	(1)	$	4	$	300	$	—	$	4