Employee Benefit Plans - Amounts Recognized in Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Other assets (noncurrent)	$ 13,699	$ 15,189
Other liabilities (current)	0	0
Other liabilities (noncurrent)	0	0
Net amount recognized	13,699	15,189
U.S.
Defined Benefit Plan Disclosure [Line Items]
Other assets (noncurrent)	0	0
Other liabilities (current)	(1,062)	(2,312)
Other liabilities (noncurrent)	(44,152)	(43,623)
Net amount recognized	$ (45,214)	$ (45,935)