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Summary of Significant Accounting Policies - Additional Information (Details)
9 Months Ended
Sep. 22, 2017
Sep. 30, 2018
segment
item
$ / shares
shares
Dec. 31, 2017
$ / shares
shares
Mar. 31, 2013
$ / shares
Summary of Significant Accounting Policies        
Stock split 0.109051      
Common stock, authorized | shares   120,000,000 120,000,000  
Common stock, par value per share | $ / shares   $ 0.001 $ 0.001 $ 0.001
Off Balance Sheet Risk and Concentrations of Credit Risk        
Number of federally insured financial institutions | item   2    
Segment Information        
Number of operating segments | segment   1    
Investor Instrument        
Expected dividend yield (as a percent)   0.00%