Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Fair Value of Financial Assets Measured on Recurring Basis (Detail)

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Fair Value Measurements - Fair Value of Financial Assets Measured on Recurring Basis (Detail) - USD ($)
$ in Thousands
Apr. 30, 2021
Jan. 31, 2021
Marketable securities:    
Marketable securities   $ 252
U.S. Treasury Notes and Bonds [Member]    
Marketable securities:    
Marketable securities   252
Fair Value, Measurements, Recurring [Member]    
Assets:    
Cash equivalents $ 46 46
Total 46 298
Fair Value, Measurements, Recurring [Member] | U.S. Treasury Notes and Bonds [Member]    
Marketable securities:    
Marketable securities   252
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]    
Assets:    
Cash equivalents 46 46
Total $ 46 298
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Treasury Notes and Bonds [Member]    
Marketable securities:    
Marketable securities   $ 252