Leases - Schedule of Minimum Lease Payments (Detail) $ in Thousands	Sep. 30, 2019 USD ($)
Leases [Abstract]
2019 (remaining 3 months)	$ 1,578
2020	6,302
2021	6,461
2022	6,390
2023	5,158
Total future minimum lease payments	25,889
Less: interest	(4,710)
Total operating lease liabilities	$ 21,179