Significant Items Making up Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Components Of Deferred Tax Assets And Liabilities [Abstract]
Allowances not currently deductible for tax purposes	$ 433	$ 902
Net operating loss carryforwards	48,860	57,548
Operating lease liabilities	1,135
General carryforwards	13,366	2,886
Stock options	1,229	1,176
Accrued and other	1,900	1,568
Deferred Tax Assets, Gross, Total	66,923	64,080
Less valuation allowance	(62,492)	(60,824)
Deferred Tax Assets, Net of Valuation Allowance, Total	4,431	3,256
Depreciation and amortization	(1,556)	(1,945)
Operating lease right-of-use assets	(1,086)
State income taxes	(1,789)	(1,311)
Deferred Tax Liabilities, Gross, Total	$ (4,431)	$ (3,256)