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Right of Use Assets - Additional Information (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Disclosure of detailed information about Right-of-use assets [Line Items]    
Additions to the right of use assets $ 40 $ 473
Cash outflow for lease $ 682 $ 691
Bottom of range [Member]    
Disclosure of detailed information about Right-of-use assets [Line Items]    
Lease term of contract 1 year  
Top Of Range [Member]    
Disclosure of detailed information about Right-of-use assets [Line Items]    
Lease term of contract 37 years