Derivatives - Amount of Gain (Loss) Recognized in OCI and Income Statement (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) recognized in OCI	$ (5,456)	$ 64	$ 901
Derivatives designated as cash flow hedges | Interest rate swap
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) recognized in OCI	(2,830)	1,559	853
Derivatives designated as cash flow hedges | Interest rate swap | Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) reclassified from AOCI	2,040	1,537	95
Derivatives designated as cash flow hedges | Foreign currency forward contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) recognized in OCI	(587)	539	491
Derivatives designated as cash flow hedges | Foreign currency forward contracts | Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) reclassified from AOCI	577	136	(277)
Derivatives designated as cash flow hedges | Foreign currency forward contracts | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) reclassified from AOCI	$ (578)	$ 361	$ 625