Commitments and Contingencies - Additional Information (Detail) (USD $)			1 Months Ended	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2011	Aug. 31, 2011 Redwood City California [Member] sqft	Mar. 31, 2014 Redwood City California [Member]	Mar. 31, 2014 Menlo Park [Member] sqft
Operating Leased Assets [Line Items]
Operating facility lease area			5,740		12,943
Operating facility lease term				30 months	39 months
Operating facility lease term commencement date				2011-10-16
Security deposit		$ 55,000
Future minimum commitments under non-cancelable operating leases	77,000
Total obligation under lease					$ 1,600,000