Income Taxes (Deferred Tax Assets (Liabilities)) (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Income Taxes [Abstract]
Reserves on inventory and sales	$ 753	$ 745
Credit and loss carryforwards	2,546	1,269
Stock compensation	1,015	756
Accrued expenses and deferred costs	3,274	2,465
Inventory capitalization	120	307
Lease obligations	2,178	3,288
Valuation allowance	(1,436)
Total deferred tax assets	8,450	8,830
Right-of-use assets	(2,032)	(3,114)
Unrealized loss on investments	(24)	(10)
Prepaid expenses	(1,022)	(1,034)
Depreciation	(4,680)	(3,365)
Total deferred tax liabilities	(7,758)	(7,523)
Net deferred tax asset	$ 692	$ 1,307