Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	May 13, 2011
Commitments and Contingencies Disclosure [Line Items]
Rent expense	$ 2,400	$ 3,000	$ 3,000
Future minimum lease payments under non-cancelable operating leases
2017	3,167
2018	3,120
2019	3,038
2020	3,031
2021	2,640
Thereafter	1,489
Total	$ 16,485
On the fifth anniversary of the lease commencement date
Commitments and Contingencies Disclosure [Line Items]
Irrevocable letter of credit delivered as a security for lease obligation				$ 1,200