Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net (loss) income attributable to stockholders		$ (1,440)	$ 306	$ 472
Earnings attributable to participating securities			(1)	(2)
Net (loss) income attributable to stockholders, net of earnings allocated to participating securities		$ (1,440)	$ 305	$ 470
Denominator:
Weighted average shares outstanding – basic		236	212	203
Unvested restricted shares			1	1
Weighted average shares outstanding – diluted		236	213	204
(Loss) Earnings per share - Basic	[1]	$ (6.11)	$ 1.44	$ 2.32
(Loss) Earnings per share - Diluted	[1]	$ (6.11)	$ 1.44	$ 2.31

[1] Per share amounts are calculated based on unrounded numbers.