Commitments and Contingencies - Additional Information (Detail) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2015 ft² Property	Dec. 31, 2015 USD ($) ft² Property	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Commitments And Contingencies [Line Items]
Additional property available under lease | Property	2	2
Property leased	41,400
Rent expenses | $		$ 0.9	$ 0.7	$ 0.7
Operating lease expiration period	5 years
Lease expiration date		Jan. 31, 2018
Research and Office Space [Member]
Commitments And Contingencies [Line Items]
Area of space leased	7,700	7,700