Annual report pursuant to Section 13 and 15(d)

Significant Accounting Policies - Additional Information (Detail)

v3.19.1
Significant Accounting Policies - Additional Information (Detail)
 12 Months Ended
Dec. 31, 2018
USD ($)
Segment
Dec. 31, 2017
USD ($)
Jan. 01, 2019
USD ($)
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]      
Cash and cash equivalents with original maturity period Three months or less    
Number of business operating segment | Segment 1    
Impairment losses $ 0 $ 0  
Uncertain income tax position, unrecognized Less than a 50%    
Uninsured portion of cash balance $ 19,958,301 $ 5,916,143  
Minimum [Member]      
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]      
Estimated useful lives of assets 3 years    
Maximum [Member]      
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]      
Estimated useful lives of assets 7 years    
Leasehold Improvements [Member]      
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]      
Estimated useful lives of assets 3 years    
Subsequent Event [Member]      
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]      
Operating lease right-of-use assets     $ 176,000
Operating lease right-of-use liabilities     $ 176,000