Income Taxes - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Contingency [Line Items]
Income tax expense benefit	$ 272			$ 59
Transition tax				16
Deferred tax balance				43
Percentage of temporary tax differences that reverse within the carryforward period		15.00%
Percentage of deferred tax asset exclusive of reversing temporary differences		85.00%
Valuation allowances				46
Foreign tax credits			$ 88	8
Deduction of foreign taxes			113
Cumulative amount of valuation allowance		$ 216
Valuation allowance	$ 2,459	2,307	2,121	2,357
Increase (decrease) to valuation allowance		$ 136	$ 19	119
Valuation allowance, changes due to losses no longer supported by temporary differences				$ 20
Percentage of the effect of unrecognized tax benefit, if recorded		1.00%	36.00%	11.00%
Interest or penalties recognized		$ 2	$ 6	$ 22
Income related to accrued interest and penalties		25	0	1
Amount accrued for payment of interest and penalties		2	23	21
Domestic Tax Authority
Income Tax Contingency [Line Items]
Valuation allowance, amount released		20	11
Increase (decrease) to valuation allowance		58	5
Foreign Tax Authority
Income Tax Contingency [Line Items]
Increase (decrease) to valuation allowance				61
Tax Authority, Spain | Foreign Tax Authority
Income Tax Contingency [Line Items]
Increase (decrease) to valuation allowance		104		$ 92
Other Net State Deferred Tax Asset
Income Tax Contingency [Line Items]
Valuation allowance			609
Capital Loss Carryforward
Income Tax Contingency [Line Items]
Valuation allowance, amount released		$ 1	$ 9