Derivative Contracts - Fair Value and Presentation in Consolidated Balance Sheets for Derivatives (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Foreign exchange contract
Derivative [Line Items]
Asset Derivatives	$ 168	$ 20
Liability Derivatives	7	627
Foreign exchange contract | Other current assets | Not Designated as Hedging Instrument
Derivative [Line Items]
Asset Derivatives	168	20
Foreign exchange contract | Accrued liabilities | Not Designated as Hedging Instrument
Derivative [Line Items]
Liability Derivatives	7	627
Interest swap contract
Derivative [Line Items]
Asset Derivatives	2,343	515
Liability Derivatives	0	246
Interest swap contract | Other assets, net | Not Designated as Hedging Instrument
Derivative [Line Items]
Asset Derivatives	2,343	515
Interest swap contract | Accrued liabilities | Not Designated as Hedging Instrument
Derivative [Line Items]
Liability Derivatives	$ 0	$ 246