Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2017	Dec. 31, 2020
Tax Credit Carryforward [Line Items]
Unrecognized tax benefits	$ 0	$ 0
Interest or penalties related to uncertain tax positions	0	0
Deferred tax assets	300,000			$ 400,000
Deferred tax liability	$ 1,700,000			$ 1,700,000
Corporate income tax rate	21.00%		35.00%
Tax Year 2016 [Member]
Tax Credit Carryforward [Line Items]
Tax years open to examination	2017
Tax Year 2019 [Member]
Tax Credit Carryforward [Line Items]
Tax years open to examination	2020
General and Administrative Expense [Member]
Tax Credit Carryforward [Line Items]
Federal and state income tax expense (benefit)	$ 600,000	$ 800,000