Derivatives - Narrative (Details) € in Thousands, ₩ in Thousands, ¥ in Thousands, ¥ in Thousands, £ in Thousands, kr in Thousands, kr in Thousands, SFr in Thousands, R$ in Thousands, $ in Thousands, $ in Thousands, $ in Thousands, $ in Thousands, $ in Thousands, $ in Thousands	6 Months Ended
	Jun. 30, 2018 USD ($) derivative_instrument	Jun. 30, 2018 CHF (SFr) derivative_instrument	Jun. 30, 2018 DKK (kr) derivative_instrument	Jun. 30, 2018 MXN ($) derivative_instrument	Jun. 30, 2018 CNY (¥) derivative_instrument	Jun. 30, 2018 KRW (₩) derivative_instrument	Jun. 30, 2018 GBP (£) derivative_instrument	Jun. 30, 2018 CAD ($) derivative_instrument	Jun. 30, 2018 JPY (¥) derivative_instrument	Jun. 30, 2018 SGD ($) derivative_instrument	Jun. 30, 2018 EUR (€) derivative_instrument	Jun. 30, 2018 HKD ($) derivative_instrument	Jun. 30, 2018 SEK (kr) derivative_instrument	Jun. 30, 2018 AUD ($) derivative_instrument	Jun. 30, 2018 BRL (R$) derivative_instrument	Dec. 31, 2017 USD ($)	Aug. 05, 2016 USD ($)
Derivative [Line Items]
Deferred taxes used to offset fair value of interest rate swap																$ (1,500)
Maturity of derivative contract (up to)	2 years
Revenue and cost of sales
Derivative [Line Items]
Amount expected to be reclassified from accumulated other comprehensive income to earnings in next twelve months, gross	$ 464
Amount expected to be reclassified from accumulated other comprehensive income to earnings in next twelve months, net of tax	345
Interest expense
Derivative [Line Items]
Amount expected to be reclassified from accumulated other comprehensive income to earnings in next twelve months, gross	2,200
Amount expected to be reclassified from accumulated other comprehensive income to earnings in next twelve months, net of tax	1,600
Interest rate swap
Derivative [Line Items]
Notional amount of derivative																	$ 175,000
Fixed rate																	1.12%
Deferred taxes used to offset fair value of interest rate swap	$ 2,100
Foreign currency forward contracts | Designated as hedging instrument
Derivative [Line Items]
Average number of contracts entered into per month | derivative_instrument	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100
Foreign currency forward contracts | Not designated as hedging instrument
Derivative [Line Items]
Notional amount of derivative		SFr 255	kr 2,885	$ 18,700	¥ 95,228	₩ 2,700,000	£ 1,584	$ 3,098	¥ 260,000	$ 6,900	€ 25,861	$ 11,000	kr 10,536	$ 8,400	R$ 8,500
Average number of contracts entered into per month | derivative_instrument	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20