Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	0 Months Ended	12 Months Ended
	Nov. 30, 2013 Lawsuits	Dec. 31, 2014 Renewal_Options sqft	Dec. 31, 2013	Dec. 31, 2012
Commitments and Contingencies Disclosure [Abstract]
Area for leasing facility of manufacturing, research laboratory and office space		68,400
Expiry date of lease		Aug. 01, 2017
Number of additional renewals for lease beyond its expiration		3
Renewal period for lease for lease beyond its expiration		5 years
Base rent paid and the rent expensed recorded as deferred rent in balance sheet		$ 1.3
Rent expense		$ 2.8	$ 2.8	$ 2.9
Number of putative, securities class action complaints filed in U.S District Court	2