Commitments and Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Future minimum lease payments under non-cancelable operating leases
2014	$ 3,285,000
2015	3,195,000
2016	3,043,000
2017	2,998,000
2018	2,343,000
Thereafter	365,000
Total	15,229,000
Total rent expense	3,500,000	3,600,000	4,600,000
Future milestone payments under Assignment and License Agreements
2014	4,300,000
2015	1,450,000
2016	2,247,000
2017	6,668,000
2018	1,075,000
Thereafter	6,170,000
Total	$ 21,910,000