XML 119 R103.htm IDEA: XBRL DOCUMENT v3.8.0.1
Income Taxes - Additional Information (Details) - USD ($)
 3 Months Ended 12 Months Ended
Dec. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Tax [Line Items]          
Corporate federal income tax rate     35.00% 35.00% 35.00%
Net income tax expense $ 7,200,000   $ 7,200,000    
Reversal of valuation allowance       $ 61,400,000  
Operating loss carryforwards, limitations on use     Pursuant to Sections 382 and 383 of the Internal Revenue Code, annual use of net operating loss and credit carryforwards may be limited in the event a cumulative change in ownership of more than 50 percent occurs within a three-year period.    
Cumulative change in ownership Percentage 50.00%   50.00%    
Period for cumulative change in ownership     3 years    
Estimated net operating losses available eah year $ 756,000   $ 756,000    
Scenario, Plan          
Income Tax [Line Items]          
Corporate federal income tax rate   21.00%