Fair Value Measurements - Financial Assets and (Liabilities) Carried at Fair Value (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
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
Contingent receivable asset	0	0
Contingent consideration liabilities	0	0
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate contracts	4,321	5,772
Foreign currency contract liabilities, current and long-term	1,431	1,578
Foreign currency contract liabilities, current and long-term	(2,057)	(1,608)
Contingent receivable asset	0	0
Contingent consideration liabilities	0	0
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
Contingent receivable asset	627	607
Contingent consideration liabilities	(82,457)	(82,236)
Estimate of Fair Value, Fair Value Disclosure
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate contracts	4,321	5,772
Foreign currency contract liabilities, current and long-term	1,431	1,578
Foreign currency contract liabilities, current and long-term	(2,057)	(1,608)
Contingent receivable asset	627	607
Contingent consideration liabilities	$ (82,457)	$ (82,236)