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) $ in Thousands	Dec. 31, 2019 USD ($)
Operating Lease Liabilities, Payments Due [Abstract]
2020	$ 1,239
2021	1,264
2022	1,288
2023	1,164
Total future minimum lease payments, undiscounted	4,955
Less imputed interest	(636)
Operating lease liability	4,319
Operating lease liability reported as of December 31, 2019:
Operating lease liability - current	967
Operating lease liability - non-current	3,352
Total	$ 4,319