Property and Equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Property and Equipment
Total property and equipment	$ 70,520	$ 69,984
Less accumulated depreciation	(61,891)	(59,020)
Property and equipment, net	8,629	10,964
Lab equipment and machinery
Property and Equipment
Total property and equipment	58,802	58,289
Leasehold improvements
Property and Equipment
Total property and equipment	6,248	6,246
Computer equipment and software
Property and Equipment
Total property and equipment	4,870	4,640
Furniture and fixtures
Property and Equipment
Total property and equipment	221	219
Construction in progress
Property and Equipment
Total property and equipment	$ 379	$ 590