Income Taxes - Summary of Valuation Allowance (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Valuation Allowance [Line Items]
Valuation allowance	$ 2,986,684	$ 2,759,431
Foreign tax credits
Valuation Allowance [Line Items]
Valuation allowance	2,540,400	2,509,786
Disallowed interest expense carryforwards
Valuation Allowance [Line Items]
Valuation allowance	138,339	88,318
Intangible assets
Valuation Allowance [Line Items]
Valuation allowance	48,395	0
U.S. loss carryforwards
Valuation Allowance [Line Items]
Valuation allowance	45,015	0
Other U.S. deferred tax assets
Valuation Allowance [Line Items]
Valuation allowance	40,659	6,393
Foreign loss carryforwards
Valuation Allowance [Line Items]
Valuation allowance	106,737	96,657
Other foreign deferred tax assets
Valuation Allowance [Line Items]
Valuation allowance	$ 67,139	$ 58,277