Earnings Per Share - Reconciliation of the Earnings (Losses) and Number of Shares Used in Calculations of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Computation of Basic (Loss) Earnings Per Share
Net (loss) income	$ (11)	$ 31
Shares for basic (loss) earnings per share (in shares)	326.7	325.4
Basic (loss) earnings per share (in USD per share)	$ (0.03)	$ 0.10
Computation of Diluted (Loss) Earnings Per Share
Net (loss) income	$ (11)	$ 31
Shares for basic (loss) earnings per share (in shares)	326.7	325.4
Effect of dilutive securities
Stock-based compensation (in shares)	0.0	2.0
Shares for diluted (loss) earnings per share (in shares)	326.7	327.4
Diluted (loss) earnings per share (in USD per share)	$ (0.03)	$ 0.09
Antidilutive shares (in shares)	2.3