Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies (Details) - Additional information (Detail)

v3.19.3.a.u2
Summary of Significant Accounting Policies (Details) - Additional information (Detail) - USD ($)
May 31, 2019
Dec. 31, 2019
Dec. 18, 2019
Mar. 31, 2019
Number of securities called by warrants or rights 5,750,000 5,750,000    
Cash equivalents   $ 0   $ 0
IPO [Member]        
Number of securities called by warrants or rights   5,750,000    
Warrant [Member] | IPO [Member]        
Number of securities called by warrants or rights 5,750,000      
Initial public offering terms and conditions of unit one share of common stock and a warrant to purchase one half of one share of common stock      
Immunovant Sciences Ltd [Member]        
Shares exchange ratio     0.48907%  
Immunovant Sciences Ltd [Member] | Restatement Adjustment [Member]        
Shares exchange ratio     0.48907%