XML 42 R79.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Income Taxes - Additional Information (Details) - USD ($)
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Income Tax Disclosure [Line Items]    
Change in valuation allowance $ 62,000  
Deferred tax assets, federal net operating loss carryforwards 136,771,000  
Deferred tax assets, state net operating loss carryforwards $ 114,459,000  
Percentage of annual limitation of taxable income 80.00%  
State net operating loss carryforward, expiration year 2028  
Tax credit carryforward, expiration year 2039  
Liabilities for uncertain tax positions $ 0 $ 0
Accrued interest or penalties related to uncertain tax positions 0 $ 0
Federal    
Income Tax Disclosure [Line Items]    
Tax credit carryforwards 6,507,000  
State    
Income Tax Disclosure [Line Items]    
Tax credit carryforwards $ 5,018,000  
Internal Revenue Service (IRS)    
Income Tax Disclosure [Line Items]    
Tax credit carryforward limitations on use, cumulative ownership change, period 3 years  
Tax credit carryforward, limitations on use an ownership change, as defined by Section 382, results from transactions that increase the ownership of five percent stockholders in the stock of a corporation by more than 50% in the aggregate over a three-year period.  
Internal Revenue Service (IRS) | Minimum    
Income Tax Disclosure [Line Items]    
Tax credit carryforward limitations on use, cumulative ownership change percentage 5.00%  
Internal Revenue Service (IRS) | Maximum    
Income Tax Disclosure [Line Items]    
Tax credit carryforward limitations on use, cumulative ownership change percentage 50.00%  
Internal Revenue Service (IRS) | Federal    
Income Tax Disclosure [Line Items]    
Income tax examination year under examination 2017  
Closed tax year 2015  
Internal Revenue Service (IRS) | State    
Income Tax Disclosure [Line Items]    
Closed tax year 2015  
UK Revenue Agency | Foreign    
Income Tax Disclosure [Line Items]    
Open tax year 2016  
Canada Revenue Agency | Foreign    
Income Tax Disclosure [Line Items]    
Open tax year 2016  
Revenue Commissioners, Ireland | Foreign    
Income Tax Disclosure [Line Items]    
Open tax year 2016