Income Taxes - Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current income taxes:
Current income taxes: U.S. federal	$ (33,821)	$ 19,936	$ 22,700
Current income taxes: State and local	7,794	12,659	14,521
Current income taxes: Foreign	72,350	80,221	58,669
Total current income taxes	46,323	112,816	95,890
Deferred income taxes:
Deferred income taxes: U.S. federal	14,533	11,993	54,983
Deferred income taxes: State and local	112	15,371	19,076
Deferred income taxes: Foreign	7,679	(135,206)	14,397
Total deferred income taxes	22,324	(107,842)	88,456
Income tax expense (benefit)	$ 68,647	$ 4,974	$ 184,346