Selected Balance Sheet Components - Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property and equipment, net:
Depreciation	$ 1,300
Total property and equipment, gross	9,687	$ 7,289
Less: Accumulated amortization	(5,638)	(4,397)
Property and Equipment	4,049	2,892
Depreciation expense	1,592	752	$ 489
Machinery and equipment
Property and equipment, net:
Total property and equipment, gross	3,280	3,135
Furniture, fixtures and office equipment
Property and equipment, net:
Total property and equipment, gross	931	777
Computer equipment and software
Property and equipment, net:
Total property and equipment, gross	2,662	667
Leasehold improvements
Property and equipment, net:
Total property and equipment, gross	2,393	1,691
Construction in progress
Property and equipment, net:
Total property and equipment, gross	$ 421	$ 1,019