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Summary of Business and Significant Accounting Policies - Schedule of Certain Risks and Concentrations of Credit Risk (Detail) - Customer concentration risk - Accounts receivable
12 Months Ended
Jan. 31, 2020
Jan. 31, 2019
Customer 1    
Concentration Risk [Line Items]    
Concentration risk percentage 14.00% 17.00%
Customer 2    
Concentration Risk [Line Items]    
Concentration risk percentage   10.00%