Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Allowance for Doubtful Accounts
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 70,000	$ 25,000
SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense		49,361
Balance at End of Period	25,000	70,000
SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction	(45,000)	(4,361)
Deferred Tax Asset Valuation Allowance
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	2,208,843	35,041,300
SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense	3,427,540	1,535,093
Balance at End of Period	3,012,513	2,208,843
SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction	(2,623,870)	(34,367,550)
SalesReturnsReservesMember [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	689,000	1,101,658
Balance at End of Period	545,000	689,000
SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction	(144,000)	(412,658)
SEC Schedule, 12-09, Reserve, Warranty [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	75,300	129,837
Balance at End of Period	49,600	75,300
SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction	$ (25,700)	$ (54,537)