Leases - Supplemental Balance Sheet Related to Finance Leases (Detail) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Property and equipment, at cost	$ 239,000
Accumulated amortization	(52,000)
Property and equipment, net	187,000
Other current liabilities – finance lease current portion	$ 119,000
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesCurrent
Other long-term liabilities	$ 71,000
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesNoncurrent
Total finance lease liabilities	$ 190,000	$ 0