Significant Items Making up Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Components Of Deferred Tax Assets And Liabilities [Abstract]
Allowances not currently deductible for tax purposes	$ 902	$ 1,177
Net operating loss carryforwards	59,606	56,989
Interest carryforwards	828
Stock options	1,176	873
Accrued and other	1,568	1,104
Deferred Tax Assets, Gross, Total	64,080	60,143
Less valuation allowance	(60,824)	(58,248)
Deferred Tax Assets, Net of Valuation Allowance, Total	3,256	1,895
Depreciation and amortization	(1,945)	(1,085)
State income taxes	(1,311)	(810)
Deferred Tax Liabilities, Gross, Total	$ (3,256)	$ (1,895)