Commitments and Contingencies - Schedule of Future Minimum Lease Payments under Non-cancellable Operating Leases, Reconciliation of Undiscounted Cash Flows to the Operating Lease Liability (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Operating Lease Liabilities, Payments Due [Abstract]
2020 (Excluding the three months ended March 31, 2020)	$ 933
2021	1,264
2022	1,288
2023	1,164
Total future minimum lease payments, undiscounted	4,649
Less imputed interest	(562)
Operating lease liability	4,087
Operating lease liability reported as of December 31, 2019:
Operating lease liability - current	991	$ 967
Operating lease liability - non-current	3,096	$ 3,352
Total	$ 4,087