Derivatives - Forward Notional Contracts (Details) - Dec. 31, 2018 - Foreign currency forward contracts € 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	AUD ($)	CNY (¥)	DKK (kr)	MXN ($)	CHF (SFr)	KRW (₩)	CAD ($)	GBP (£)	JPY (¥)	SGD ($)	SEK (kr)	EUR (€)	HKD ($)	BRL (R$)
Not designated as hedging instrument
Derivative [Line Items]
Notional amount of derivative	$ 11,400	¥ 63,200	kr 3,237	$ 23,000	SFr 269	₩ 5,500,000	$ 2,300	£ 2,358	¥ 265,000	$ 8,500	kr 9,627	€ 5,927	$ 11,000	R$ 9,000
Derivatives designated as cash flow hedges | Designated as hedging instrument
Derivative [Line Items]
Notional amount of derivative	$ 3,000	¥ 160,000	kr 17,225	$ 230,000	SFr 2,145	₩ 3,050,000	$ 4,410	£ 5,280	¥ 1,145,000		kr 30,210	€ 20,310