Income Taxes - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Impairment losses	$ 555	$ 1,400	$ 572
Tax regulations passed in 2020 related to GILTI - unfavorable (favorable)	(14)
Expense (benefit) related to release of valuation allowances	(20)
Tax reform impact on adjustments			92
Operating loss carrybacks, amount			$ 142
Net deferred tax liability	3,150	2,780
Deferred income tax liabilities, net	3,342	2,918
Deferred income tax assets, net	191	118
Valuation allowance	1,538	1,319
Valuation allowance, DTA, increase (decrease), amount	(219)
Unrecognized tax benefits that would impact effective tax rate	267	259
Interest on income taxes accrued	23	$ 15
Significant change in unrecorded benefit	3
Federal
Operating Loss Carryforwards [Line Items]
Operating loss carryforward	5,077
State
Operating Loss Carryforwards [Line Items]
Operating loss carryforward	17,000
Foreign
Operating Loss Carryforwards [Line Items]
Operating loss carryforward	$ 7,000