Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenue:
Products	$ 83,835	$ 62,561	$ 162,350	$ 124,560
Services	1,342	1,518	2,781	3,330
Total revenue	85,177	64,079	165,131	127,890
Cost of revenue:
Products	57,052	41,692	107,741	80,936
Services	1,522	172	2,458	598
Depreciation	512	497	1,099	845
Total cost of revenue	$ 59,086	$ 42,361	$ 111,298	$ 82,379