Leases - Summary of Balance Sheet Classification of Lease Liabilities (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Operating lease liabilities
Current portion of lease liabilities	$ 3,434,000
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccruedLiabilitiesCurrent
Operating lease liabilities	$ 6,361,000
Total operating lease liabilities	$ 9,795,000	$ 0