Fair Value Measurements - Financial Assets and (Liabilities) Carried at Fair Value (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate contracts	$ 0	$ 0
Foreign currency contract liabilities, current and long-term	0	0
Foreign currency contract liabilities, current and long-term	0	0
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate contracts	5,749	4,991
Foreign currency contract liabilities, current and long-term	621	354
Foreign currency contract liabilities, current and long-term	(1,391)	(464)
Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate contracts	0	0
Foreign currency contract liabilities, current and long-term	0	0
Foreign currency contract liabilities, current and long-term	0	0
Estimate of Fair Value, Fair Value Disclosure
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate contracts	5,749	4,991
Foreign currency contract liabilities, current and long-term	621	354
Foreign currency contract liabilities, current and long-term	$ (1,391)	$ (464)