Leases - Elements of Lease Expense (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2019 USD ($)
Lease cost:
Operating lease cost	$ 2,405
Variable lease cost	323	[1]
Sublease income	(105)
Total Lease cost	2,623
Operating cash flows used for operating leases	2,322
Operating lease liabilities arising from obtaining right-of-use assets	$ 11,863
Weighted-average remaining lease term in years	3 years 9 months 18 days
Weighted-average discount rate	10.37%

[1] The variable lease costs for the nine months ended September 30, 2019 include common area maintenance charges.