Unaudited Quarterly Information (Tables)

12 Months Ended

Dec. 31, 2015

Unaudited Quarterly Information [Abstract]

Quarterly financial data

Summarized quarterly financial data is as follows:

	Year Ended December 31, 2015
	First Quarter		Second Quarter		Third Quarter (1)			Fourth Quarter (2)
	(in millions)
Revenues	$	1,817	$	824	$	799		$	1,087
Operating income	160		27		18			108
Net income (loss)	109		22		(508		)	(535		)

	Year Ended December 31, 2014
	First Quarter		Second Quarter		Third Quarter			Fourth Quarter
	(in millions)
Revenues	$	2,531	$	1,183	$	964		$	1,689
Operating income (loss)	188		39		(3		)	111
Net income	152		48		28			95

(1) CERC recognized $862 million ($537 million after tax) in impairment charges related to Enable during the three months ended September 30, 2015.

(2) CERC recognized $984 million ($620 million after tax) in impairment charges related to Enable during the three months ended December 31, 2015.