Fair Value Measurements - Financial Assets and (Liabilities) Carried at Fair Value (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate contracts	$ 1,201	$ 5,772
Foreign currency contract liabilities, current and long-term	2,858	1,578
Foreign currency contract liabilities, current and long-term	(2,100)	(1,608)
Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent receivable asset	506	607
Contingent consideration liabilities	(79,608)	(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	1,201	5,772
Foreign currency contract liabilities, current and long-term	2,858	1,578
Foreign currency contract liabilities, current and long-term	(2,100)	(1,608)
Contingent receivable asset	506	607
Contingent consideration liabilities	$ (79,608)	$ (82,236)