Goodwill and Intangible Assets, Net - Carrying Value of Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Schedule of Goodwill and Intangible Assets [Line Items]
Cost	$ 17,244		$ 17,244		$ 15,455
Accumulated Amortization	(2,679)		(2,679)		(3,094)
Net Book Value	14,565		14,565		12,361
Intangible assets not subject to amortization	40		40		40
Total intangible assets, net	14,605		14,605		12,401
Amortization of intangible assets	900	$ 100	1,500	$ 200
Goodwill	1,849		$ 1,849		1,549
Developed technology
Schedule of Goodwill and Intangible Assets [Line Items]
Weighted Average Life (Years)			5 years
Weighted Average Remaining Life (Years)			4 years 1 month 10 days	4 years 9 months 15 days
Cost	15,856		$ 15,856		14,067
Accumulated Amortization	(1,907)		(1,907)		(2,371)
Net Book Value	13,949		$ 13,949		11,696
Patent licenses
Schedule of Goodwill and Intangible Assets [Line Items]
Weighted Average Life (Years)			14 years
Weighted Average Remaining Life (Years)			6 years 1 month 13 days	6 years 7 months 29 days
Cost	1,388		$ 1,388		1,388
Accumulated Amortization	(772)		(772)		(723)
Net Book Value	$ 616		$ 616		$ 665