Fair Value Measurements and Derivative Instruments (Held-to-Maturity Securities and Derivative Instruments) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Time deposits	$ 383,000
Total net derivative asset	1,854	$ 1,296
Total derivative assets
Derivative [Line Items]
Derivative asset	3,256	2,031
Total derivative liabilities
Derivative [Line Items]
Derivative liability	(1,402)	(735)
Foreign exchange contracts | Derivatives designated as hedging instruments | Other current assets and prepayments
Derivative [Line Items]
Derivative asset	207	61
Foreign exchange contracts | Derivatives designated as hedging instruments | Accounts payable and accrued liabilities
Derivative [Line Items]
Derivative liability	(56)	(104)
Foreign exchange contracts | Derivatives not designated as hedging instruments | Other current assets and prepayments
Derivative [Line Items]
Derivative asset	3,049	1,970
Foreign exchange contracts | Derivatives not designated as hedging instruments | Accounts payable and accrued liabilities
Derivative [Line Items]
Derivative liability	(1,346)	(631)
Cash Flow Hedging
Derivative [Line Items]
Total notional amount of outstanding contracts	7,000	$ 8,000
Cash Flow Hedging | Interest rate contract
Derivative [Line Items]
Total notional amount of outstanding contracts	$ 300,000