Annual report pursuant to Section 13 and 15(d)

Income Taxes - Additional Information (Detail)

v3.10.0.1
Income Taxes - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Income Taxes [Line Items]      
Tax computed at federal rate, percentage 21.00% 35.00% 35.00%
Tax Cuts and Jobs Act of 2017, completed accounting, income tax expense $ 0 $ 11,644,000 $ 0
State and Canadian net operating losses (NOLs) $ 9,400,000 7,800,000  
State and Canadian net operating losses (NOLs), expiration year 2033    
Valuation allowance, deferred tax assets $ 2,600,000 1,900,000  
Change in valuation allowance, deferred tax assets 677,000 $ 170,000 $ 412,000
Decrease in unrecognized tax benefits that is reasonably possible 434,000    
Unrecognized tax benefits related to penalties $ 167,000    
Income Tax Examination, Description The Company is not currently under income tax examination by any taxing authority.    
Undistributed earnings of foreign subsidiary $ 0    
Minimum [Member]      
Income Taxes [Line Items]      
Open tax years subject to tax examinations 2014    
Maximum [Member]      
Income Taxes [Line Items]      
Open tax years subject to tax examinations 2018