Goodwill and Intangible Assets, Net - Components of Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets, Net [Abstract]
Gross	$ 63,898	$ 62,924
Accumulated Amortization	(41,852)	(38,554)
Net	22,046	24,370
Gross value of fully amortized intangible assets	7,200	7,100
Distribution rights
Finite-Lived Intangible Assets, Net [Abstract]
Gross	326	329
Accumulated Amortization	(199)	(188)
Net	127	141
Patents
Finite-Lived Intangible Assets, Net [Abstract]
Gross	15,254	14,560
Accumulated Amortization	(6,041)	(5,704)
Net	9,213	8,856
Trademarks and trade names
Finite-Lived Intangible Assets, Net [Abstract]
Gross	2,786	2,786
Accumulated Amortization	(2,053)	(1,900)
Net	733	886
Developed and core technology
Finite-Lived Intangible Assets, Net [Abstract]
Gross	12,560	12,560
Accumulated Amortization	(9,095)	(8,087)
Net	3,465	4,473
Capitalized software development costs
Finite-Lived Intangible Assets, Net [Abstract]
Gross	288	155
Accumulated Amortization	0	0
Net	288	155
Customer relationships
Finite-Lived Intangible Assets, Net [Abstract]
Gross	32,684	32,534
Accumulated Amortization	(24,464)	(22,675)
Net	$ 8,220	$ 9,859