Commitments and Contingencies - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) ft²	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Commitments And Contingencies Disclosure [Abstract]
Operating leases expiration period	2020-12
Square Feet of Office and Laboratory | ft²	49,000
Rent expenses	$ 4.2	$ 1.9	$ 1.7
Purchase commitments expiration year	2020
Capital lease expiration year	2020
Weighted average interest rates	6.03%
Base salaries expected in 2016	$ 2.4