Annual report pursuant to Section 13 and 15(d)

Income Taxes - Additional Information (Detail)

v3.8.0.1
Income Taxes - Additional Information (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Tax Disclosure [Line Items]        
Valuation allowance   $ 40,866 $ 54,310  
Net operating loss carryforwards federal   147,000    
Net operating loss carryforwards state   $ 87,000    
Corporate tax rate   34.00% 34.00% 34.00%
Reduction in net deferred tax assets, before valuation allowance due to change in corporate tax rate   $ 21,700    
Net impact of change in federal corporate rate on deferred tax liability   $ 300    
Percentage of limitation on utilization of net operating losses of taxable income   80.00%    
Deferred tax liability   $ 500    
Reduction in deferred tax liability   100    
Recognized deferred tax benefit   400    
Unremitted earnings of foreign subsidiaries   $ 600    
Scenario Forecast        
Income Tax Disclosure [Line Items]        
Corporate tax rate 21.00%      
Minimum        
Income Tax Disclosure [Line Items]        
Operating loss carryforwards, expiration period   2018    
Maximum        
Income Tax Disclosure [Line Items]        
Operating loss carryforwards, expiration period   2037    
Federal        
Income Tax Disclosure [Line Items]        
Research and development tax credit carryforwards   $ 1,400    
Federal | Minimum        
Income Tax Disclosure [Line Items]        
Research and development tax credit carryforwards, expiration period   2018    
Federal | Maximum        
Income Tax Disclosure [Line Items]        
Research and development tax credit carryforwards, expiration period   2037    
State | Indefinite Life        
Income Tax Disclosure [Line Items]        
Research and development tax credit carryforwards   $ 1,800