Derivative Instruments - Gain (Loss) Recognized in Other Comprehensive Income (Loss) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses) reclassified from accumulated other comprehensive income (loss) into net income	$ (398,000)	$ (201,000)	$ (46,000)
Accumulated other comprehensive income (loss), net of tax | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in shareholders' equity (effective portion)	37,000	206,000	32,000
Total gains (losses) reclassified from accumulated other comprehensive income (loss) into net income	(398,000)	(201,000)	(46)
Product Revenue | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) reclassified from accumulated other comprehensive income (loss) into net income (effective portion)	(438,000)	(387,000)	(14)
Research, development, and engineering expenses | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) reclassified from accumulated other comprehensive income (loss) into net income (effective portion)	13,000	14,000	(42)
Selling, general and administrative expenses | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) reclassified from accumulated other comprehensive income (loss) into net income (effective portion)	27,000	172,000	10
Foreign currency gain (loss) | Designated as Hedging Instrument [Member]
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Gains (losses) recognized in net income on derivatives (ineffective portion and discontinued derivatives)	0	0	0
Foreign currency gain (loss) | Not Designated as Hedging Instrument [Member]
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Gains (losses) recognized in net income	$ (515,000)	$ (13,000)	$ 247,000