Leases - Schedule of Components of Lease Expense (Detail) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2019 USD ($)
Leases [Abstract]
Fixed operating lease cost	$ 225	$ 610
Short-term lease costs	38	84
Total lease expense	263	694
Operating cash flows from operating leases	$ 268	737
Leased assets obtained in exchange for new operating lease liabilities		$ 484
Weighted-average remaining lease term-operating leases (in years)	3 years 3 months 18 days	3 years 3 months 18 days
Weighted-average discount rate-operating leases	9.00%	9.00%