Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator:
Net (loss) income attributable to stockholders		$ (276)	$ 5	$ (1,223)	$ 183
Loss allocated to participating securities					(1)
Net (loss) income attributable to stockholders, net of earnings allocated to participating securities		$ (276)	$ 5	$ (1,223)	$ 182
Denominator:
Weighted average shares outstanding – basic		235	206	236	203
Unvested restricted shares			1		1
Weighted average shares outstanding – diluted		235	207	236	204
(Loss) Earnings per share - Basic	[1]	$ (1.17)	$ 0.02	$ (5.19)	$ 0.90
(Loss) Earnings per share - Diluted	[1]	$ (1.17)	$ 0.02	$ (5.19)	$ 0.90

[1] Per share amounts are calculated based on unrounded numbers and are calculated independently for each period presented.