Commitments and Contingencies - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended	6 Months Ended
	May 31, 2016	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Mar. 31, 2017	Dec. 31, 2016
Other Commitments [Line Items]
Deferred lease obligation			$ 1,563			$ 1,570
Lease minimum rental payment			$ 7,829
Stamford Operating Lease [Member]
Other Commitments [Line Items]
Operating Lease, description			The Stamford Lease requires monthly lease payments, including rent escalations and rent holidays, during the initial lease term. The Company began to make rental payments from the Commencement Date. The Company records monthly rent expense on a straight-line basis from March 2016, upon taking possession of the Premises, through October 2023. As of June 30, 2017 and December 31, 2016, the balance of deferred lease obligation, representing the difference between cash rent paid and straight-line rent expense, was $648 and $583, respectively. The Stamford Lease is renewable for one five-year term.
Operating Lease, renewable term			5 years
Operating lease, expiration date			Oct. 31, 2023
Deferred lease obligation			$ 648			583
Tenant improvement expenses			1,094
Lease minimum rental payment			7,557
Stamford Operating Lease [Member] | Leasehold Improvements [Member]
Other Commitments [Line Items]
Deferred lease obligation			$ 915			987
Stamford Operating Lease [Member] | Standby Letter of Credit [Member]
Other Commitments [Line Items]
Operating lease, renewable term description			Automatically renewed annually through November 2023.
Stamford Operating Lease [Member] | Maximum [Member] | Standby Letter of Credit [Member]
Other Commitments [Line Items]
Letter of credit, renewal date			Nov. 30, 2023
Shelton Operating Lease [Member]
Other Commitments [Line Items]
Operating lease, expiration date			Oct. 13, 2017
Accrued cease use date liability	$ 1,312
Lease minimum rental payment			$ 272
Restructuring liability		$ 1,232	276	$ 1,232	$ 515	756
Additional amortization expense		$ 359		$ 899
Additional loss per share		$ 0.01		$ 0.03
Shelton Operating Lease [Member] | Standby Letter of Credit [Member]
Other Commitments [Line Items]
Letter of credit, remaining amount			$ 700			$ 700
Letter of credit, expiration date			Oct. 31, 2017