Commitments - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Lease commencement date	Jan. 01, 2017
Lease expiry date	Jan. 31, 2022
Operating lease ROU asset		$ 139,000	$ 136,000
Operating lease ROU liability		139,000	$ 136,000
Operating lease ROU	$ 141,705	138,538
Operating lease liability	$ 141,705	138,538
Operating lease incremental borrowing rate	10.00%
Rent expense	$ 151,000	$ 145,000
Future minimum facility lease payments due in 2021	137,000
Future minimum facility lease payments due in 2022	12,000
Accounting Standards Update 2016-02
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Operating lease ROU	142,000
Operating lease liability	$ 142,000