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Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Accounting Policies [Line Items]        
Provision for federal income taxes     $ 0  
Number of days in United States for tax purposes     183 days  
Sponsor [Member] | Professional Fees Liability [Member]        
Accounting Policies [Line Items]        
Legal fees and expenses assumed     $ 100,000  
Excess amount of assumed audit fees and legal expenses     100,000  
Non-recurring fees and expenses $ 0 $ 0 $ 0 $ 0