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Organization and Summary of Significant Accounting Policies - Additional Information (Detail) - shares
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Property, Plant and Equipment [Line Items]      
Short-term investment maturity period 3 months    
Weighted average number of common shares outstanding 10,538,114 9,346,213 8,583,795
Minimum [Member]      
Property, Plant and Equipment [Line Items]      
Property and Equipment, estimated useful life 3 years    
Maximum [Member]      
Property, Plant and Equipment [Line Items]      
Property and Equipment, estimated useful life 30 years