Income Taxes - Schedule of Income Taxes (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
(Loss) income before income taxes	$ (52)	$ 455	$ (137)	$ 1,235
Estimated annualized effective tax rate			(686.20%)	43.60%
Income tax expense			$ 942	$ 538
(Favorable) unfavorable tax impact related to losses in jurisdictions with no tax benefit			(590)	5
Discrete tax charge			9	26
Provision for income taxes	$ 95	$ 260	$ 361	$ 569