Other Balance Sheet Details - Summary of Accounts Payable and Accrued Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Customer advance	$ 5,000	$ 0
Accrued research and development expenses	4,257	4,102
Operating lease liabilities – current	3,690	3,214
Accrued professional fees	1,532	1,118
Other accrued liabilities	4,133	2,451
Total other accrued liabilities	$ 18,612	$ 10,885
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccruedLiabilitiesCurrent	us-gaap:AccruedLiabilitiesCurrent