Supplemental Condensed Consolidating Financial Information - Condensed Consolidating Statements of Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Statement of Income Captions [Line Items]
Net income	$ (47)	$ 42	$ 33	$ 24	$ 30	$ 46	$ 39	$ 28	$ 52	$ 143	$ 62
Other comprehensive income (loss), net of tax									2	(3)	0
Comprehensive income									54	140	62
Eliminations
Condensed Statement of Income Captions [Line Items]
Net income									(119)	(190)	(89)
Other comprehensive income (loss), net of tax									(1)	3	0
Comprehensive income									(120)	(187)	(89)
Parent Guarantor
Condensed Statement of Income Captions [Line Items]
Net income									52	143	62
Other comprehensive income (loss), net of tax									2	(3)	0
Comprehensive income									54	140	62
Parent Guarantor | Reportable Legal Entities
Condensed Statement of Income Captions [Line Items]
Net income									52	143	62
Other comprehensive income (loss), net of tax									2	(3)	0
Comprehensive income									54	140	62
Other Guarantors | Reportable Legal Entities
Condensed Statement of Income Captions [Line Items]
Net income									4	18	14
Other comprehensive income (loss), net of tax									0	0	0
Comprehensive income									4	18	14
Non-Guarantors | Reportable Legal Entities
Condensed Statement of Income Captions [Line Items]
Net income									115	172	75
Other comprehensive income (loss), net of tax									1	(3)	0
Comprehensive income									$ 116	$ 169	$ 75