Employee Benefit Plans Employee Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2014

Compensation and Retirement Disclosure [Abstract]

Schedule of Net Benefit Costs [Table Text Block]

CERC’s employees participate in CenterPoint Energy’s postretirement benefit plan. CERC’s net periodic cost includes the following components relating to postretirement benefits:

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2014		2013		2014		2013
	(in millions)
Interest cost on accumulated benefit obligation	$	2	$	1	3		2
Amortization of prior service cost	—		—		—		1
Amortization of loss	—		1		—		1
Net periodic cost	$	2	$	2	$	3	$	4