Derivatives Notional Amounts - Not Designated as Hedges (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Derivative [Line Items]
Notional Amount	$ 62,869		$ 62,869		$ 79,973
Gain (Loss)			(59)		(1,458)
Forward exchange contracts—net
Derivative [Line Items]
Gain (Loss)	1,476	$ 201	(59)	$ (144)
AUD / USD
Derivative [Line Items]
Notional Amount	2,909		2,909		7,300
Gain (Loss)			(11)		117
CAD / USD
Derivative [Line Items]
Notional Amount	5,290		5,290		6,016
Gain (Loss)			(47)		(6)
CNY / USD
Derivative [Line Items]
Notional Amount	38,652		38,652		3,200
Gain (Loss)			64		(14)
EUR / USD
Derivative [Line Items]
Notional Amount	7,655		7,655		53,365
Gain (Loss)			(54)		(1,585)
CHF / AUD
Derivative [Line Items]
Notional Amount	16		16		0
Gain (Loss)			2		0
DKK / USD
Derivative [Line Items]
Notional Amount	3,786		3,786		0
Gain (Loss)			(50)		0
GBP / USD
Derivative [Line Items]
Notional Amount	1,974		1,974		5,592
Gain (Loss)			(9)		18
NOK / USD
Derivative [Line Items]
Notional Amount	1,396		1,396		0
Gain (Loss)			6		0
NZD / USD
Derivative [Line Items]
Notional Amount	336		336		4,500
Gain (Loss)			43		12
AUD / CAD
Derivative [Line Items]
Notional Amount	853		853		0
Gain (Loss)			(3)		0
EUR / NOK
Derivative [Line Items]
Notional Amount	$ 2		2		0
Gain (Loss)			$ 0		$ 0