Leases - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Leases [Abstract]
Operating lease term	5 years
Rental expense for operating leases		$ 900
Right-of-use asset	$ 7,798
Operating lease liabilities	10,055
Cash paid for lease liabilities for operating leases	600
Right-of-use assets obtained in exchange for operating lease obligations	100
Operating lease obligations	$ 100
Weighted average remaining operating lease term	4 years 10 months 17 days
Weighted average discount rate	8.61%