Description of Business, Basis of Presentation and Significant Accounting Policies - Components of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Description of Business, Basis of Presentation and Significant Accounting Policies [Abstract]
Net (loss) income attributable to common stockholders	$ (74)	$ 13	$ (4)	$ (2)	$ 58	$ 49	$ 64	$ (46)	$ (67)	$ 125	$ (214)
Weighted average outstanding shares of common stock									125.8	129.7	139.6
Dilutive effect of employee stock options, restricted shares and other stock awards									0.0	1.8	0.0
Common stock and common stock equivalents									125.8	131.5	139.6
Net (loss) income per share:
Basic (in usd per share)	$ (0.61)	$ 0.11	$ (0.03)	$ (0.02)	$ 0.45	$ 0.38	$ 0.49	$ (0.36)	$ (0.53)	$ 0.96	$ (1.53)
Diluted (in usd per share)	$ (0.61)	$ 0.10	$ (0.03)	$ (0.02)	$ 0.44	$ 0.37	$ 0.49	$ (0.36)	$ (0.53)	$ 0.95	$ (1.53)