Income Taxes - Income Tax Provision and Effective Income Tax Rate (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Tax Disclosure [Abstract]
Income tax (provision) benefit	$ (228)	$ 27	$ (246)	$ (52)
Effective income tax rate	48.50%	337.50%	31.10%	11.50%