Derivatives and Hedging - Gains (Losses) Associated with Fair Value and Cash Flow Hedges (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivative Instruments, Gain (Loss)
After-Tax Amount of Gain (Loss) Reclassified from AOCI into Earnings	$ (550)	$ (1,784)	$ (1,920)	$ (3,091)
Foreign currency contracts | Total cost of revenue
Derivative Instruments, Gain (Loss)
After-Tax Amount of Gain (Loss) Reclassified from AOCI into Earnings	(288)	(1,522)	(1,134)	(2,305)
Interest rate contracts | Interest expense
Derivative Instruments, Gain (Loss)
After-Tax Amount of Gain (Loss) Reclassified from AOCI into Earnings	$ (262)	$ (262)	$ (786)	$ (786)