Property and Equipment (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property and Equipment
Total property and equipment	$ 67,860,000	$ 64,122,000
Less accumulated depreciation	(52,125,000)	(45,016,000)
Property and equipment, net	15,735,000	19,106,000
Impairment expenses	0	0	$ 0
Depreciation expense	7,314,000	10,220,000	$ 8,781,000
Lab equipment and machinery
Property and Equipment
Total property and equipment	55,649,000	53,412,000
Leasehold improvements
Property and Equipment
Total property and equipment	6,116,000	5,892,000
Computer equipment and software
Property and Equipment
Total property and equipment	4,263,000	3,774,000
Furniture and fixtures
Property and Equipment
Total property and equipment	207,000	197,000
Construction in progress
Property and Equipment
Total property and equipment	$ 1,625,000	$ 847,000