Annual report pursuant to Section 13 and 15(d)

Income Taxes - Additional Information (Detail)

v3.10.0.1
Income Taxes - Additional Information (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Income Tax Disclosure [Line Items]      
Valuation allowance $ 46,967 $ 40,866  
Net operating loss carryforwards federal 164,600    
Net operating loss carryforwards state $ 98,600    
Corporate tax rate 21.00% 34.00% 34.00%
Reduction in net deferred tax assets, before valuation allowance due to change in corporate tax rate   $ 21,700  
Percentage of limitation on utilization of net operating losses of taxable income   80.00%  
Interest expense dedution of adjusted taxable income percentage 30.00%    
Deferred tax assets available to offset naked credit balance $ 500    
Naked credit balance 629 $ 608  
Net deferred tax liability 77 $ 104  
Unremitted earnings of foreign subsidiaries 600    
Current income related to the GILTI $ 100    
Minimum      
Income Tax Disclosure [Line Items]      
Operating loss carryforwards, expiration period 2019    
Maximum      
Income Tax Disclosure [Line Items]      
Operating loss carryforwards, expiration period 2038    
Deferred tax asset related to net operating loss percentage 80.00%    
Deferred tax assets of excess interest carryforward percentage 30.00%    
Federal      
Income Tax Disclosure [Line Items]      
Research and development tax credit carryforwards $ 2,100    
Federal | Minimum      
Income Tax Disclosure [Line Items]      
Research and development tax credit carryforwards, expiration period 2019    
Federal | Maximum      
Income Tax Disclosure [Line Items]      
Research and development tax credit carryforwards, expiration period 2038    
State | Indefinite Life      
Income Tax Disclosure [Line Items]      
Research and development tax credit carryforwards $ 2,000