Hedging - Derivative Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Foreign currency forward contracts \| Cash flow hedging
Derivative [Line Items]
Total assets	$ 20,183	$ 20,537
Total liabilities	(378)	(448)
Designated as hedging instruments \| Foreign currency forward contracts \| Cash flow hedging
Derivative [Line Items]
Total assets	20,183	20,537
Total liabilities	(378)	(448)
Prepaid expenses and other current assets \| Designated as hedging instruments
Derivative [Line Items]
Fair Value - assets	19,210	19,023
Other current liabilities \| Designated as hedging instruments
Derivative [Line Items]
Fair Value - liabilities	(310)	(340)
Other assets \| Designated as hedging instruments
Derivative [Line Items]
Fair Value - assets	973	1,514
Other long-term liabilities \| Designated as hedging instruments
Derivative [Line Items]
Fair Value - liabilities	$ (68)	$ (108)

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Fair value as of the balance sheet date of all foreign currency derivative assets designated as cash flow hedging instruments.

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Fair value as of the balance sheet date of all foreign currency derivative liabilities designated as cash flow hedging instruments.

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