Hedging - Derivative Instruments on the Consolidated Statements of Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Total derivative instrument expense	$ 881	$ 627	$ 627
Cost of sales
Derivatives, Fair Value [Line Items]
Total derivative instrument expense	281	187	178
Research and development
Derivatives, Fair Value [Line Items]
Total derivative instrument expense	436	305	295
Selling, general and administrative
Derivatives, Fair Value [Line Items]
Total derivative instrument expense	$ 164	$ 135	$ 154