Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Schedule Of Income Tax [Line Items]
Total income tax expense (benefit)	$ (124,000)	$ 2,000
Increase (decrease) in net valuation allowance	$ 1,900,000	$ (25,900,000)
Operating loss carryforwards limitations on use	it has not forfeited the right to carryforward tax losses up to 20 years
Tax years subject to examination to extent of NOLs being carried forward	2001
Maximum [Member]
Schedule Of Income Tax [Line Items]
Right to carryforward tax losses, period	20 years
Tax year subject to examination by the tax authorities	2020
Minimum [Member]
Schedule Of Income Tax [Line Items]
Tax year subject to examination by the tax authorities	2001
Federal [Member]
Schedule Of Income Tax [Line Items]
Aggregate amount of net operating loss	$ 55,800,000
Operating loss carryforward generated	193,100,000
Operating loss carryforward unutilized	7,200,000
Operating loss carryforward expected to be unavailable	130,500,000
State [Member]
Schedule Of Income Tax [Line Items]
Aggregate amount of net operating loss	$ 57,200,000