Commitments and Contingencies (Details Textual) (USD $) In Millions, unless otherwise specified	0 Months Ended	12 Months Ended			0 Months Ended
	Apr. 06, 2005	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Feb. 17, 2012	May 03, 2012
Lessor Leasing Arrangements, Operating Leases, Term of Contract	8 years
Lessor Leasing Arrangements, Operating Leases, Renewal Term		5 years
Operating Leases, Rent Expense		$ 1.6	$ 1.5	$ 1.4
Amended Lease [Member]
Lessor Leasing Arrangements, Operating Leases, Term of Contract					10 years
Regents Of University Of California [Member]
Period for payment of initial license fees						30 days
Massachusetts Institute Of Technology [Member]
Agreement Termination Period						June 2015