Income Taxes - Components of Income Tax Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current tax expense:
U.S. federal	$ 2,817	$ 48,339	$ 58,616
State and local	6,969	434	11,292
Foreign	45,042	38,602	27,536
Total current	54,828	87,375	97,444
Deferred tax (benefit) expense:
U.S. federal	12,462	(176,046)	(61)
State and local	1,258	(14,363)	(349)
Foreign	(13,795)	(25,898)	(1,626)
Total deferred	(75)	(216,307)	(2,036)
Total current and deferred	54,753	(128,932)	95,408
Total tax expense (benefit)	58,665	(131,096)	94,849
Benefit (expense) relating to interest rate swaps used to increase (decrease) equity
Deferred tax (benefit) expense:
Other tax benefit (expense)	3,840	(2,477)	(1,113)
Benefit from stock transactions with employees used to increase equity
Deferred tax (benefit) expense:
Other tax benefit (expense)	58	46	52
Benefit relating to defined-benefit pension adjustments used to increase equity
Deferred tax (benefit) expense:
Other tax benefit (expense)	$ 14	$ 267	$ 502