Income Taxes - Summary of the Provision for Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income (loss) before income taxes	$ 825	$ (1,501)	$ (145)	$ 3,259
Income tax expense (benefit)	$ 472	$ (333)	$ 1,310	$ 584
Effective tax rate	57.20%	22.20%	(903.40%)	17.90%