Income Taxes - Components of Income Tax Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current tax expense:
U.S. federal	$ 14,480	$ 30,208	$ 2,817
State and local	16,360	11,630	6,969
Foreign	62,993	53,105	45,042
Total current	93,833	94,943	54,828
Deferred tax (benefit) expense:
U.S. federal	(7,206)	(16,389)	12,462
State and local	(13,121)	(6,897)	1,258
Foreign	(22,673)	(48,186)	(13,795)
Total deferred	(43,000)	(71,472)	(75)
Total current and deferred	50,833	23,471	54,753
Total tax expense	59,388	42,449	58,665
Benefit relating to interest rate swaps used to increase equity
Deferred tax (benefit) expense:
Other tax benefit (expense)	8,257	17,666	3,840
Benefit from stock transactions with employees used to increase equity
Deferred tax (benefit) expense:
Other tax benefit (expense)	56	54	58
Benefit relating to defined-benefit pension adjustments used to increase equity
Deferred tax (benefit) expense:
Other tax benefit (expense)	$ 242	$ 1,258	$ 14