Commitments and Contingencies - Additional Information (Detail) $ in Millions		3 Months Ended		6 Months Ended
	Sep. 19, 2016 USD ($) Installment	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) $ / ft²	Jun. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Leases [Abstract]
Expiration of non-cancellable operating leases				Through 2022
Accrued lease commitments expense		$ 3.6		$ 3.6
Estimated sublease income		1.9		1.9
Rent expense under operating leases		0.6	$ 0.5	$ 1.0	$ 0.8
Incentives per square feet | $ / ft²				40.00
Incentives for improvements to space				$ 2.2
Lease agreement term				10 years
Funds to be repaid under the agreement	$ 0.3	$ 0.3		$ 0.3		$ 0.3
Amount received to start-up new facility	$ 1.0
Interest rate of funds under the agreement	0.00%
Number of equal quarterly installments | Installment	20