Derivatives and Hedging - Gains (Losses) Associated with Fair Value and Cash Flow Hedges (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments, Gain (Loss)
Gain (loss) on foreign currency contracts, pre-tax		$ 5,000	$ (3,000)
After-tax amount of gain (loss) recognized in OCI	$ (5,207)	5,499	(5,943)
After-tax amount of gain (loss) reclassified from AOCI into earnings	(5,481)	808	(4,823)
Commodity contracts
Derivative Instruments, Gain (Loss)
After-tax amount of gain (loss) recognized in OCI	0	44	401
Commodity contracts | Total cost of revenue
Derivative Instruments, Gain (Loss)
After-tax amount of gain (loss) reclassified from AOCI into earnings	0	52	(550)
Foreign currency contracts
Derivative Instruments, Gain (Loss)
After-tax amount of gain (loss) recognized in OCI	(5,207)	5,455	(6,344)
Foreign currency contracts | Total cost of revenue
Derivative Instruments, Gain (Loss)
After-tax amount of gain (loss) reclassified from AOCI into earnings	(4,432)	1,805	(3,224)
Interest rate contracts | Interest expense
Derivative Instruments, Gain (Loss)
After-tax amount of gain (loss) reclassified from AOCI into earnings	$ (1,049)	$ (1,049)	$ (1,049)