Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Summary of Marketable Securities by Security Type (Detail)

v3.20.2
Fair Value Measurements - Summary of Marketable Securities by Security Type (Detail) - USD ($)
$ in Thousands
Jul. 31, 2020
Jan. 31, 2020
Schedule Of Available For Sale Securities [Line Items]    
Amortized Cost $ 2,092 $ 4,564
Gross Unrealized Gains 49 53
Fair Value 2,141 4,617
U.S. Treasury Notes and Bonds [Member]    
Schedule Of Available For Sale Securities [Line Items]    
Amortized Cost 1,841 3,310
Gross Unrealized Gains 46 50
Fair Value 1,887 3,360
Corporate Bonds [Member]    
Schedule Of Available For Sale Securities [Line Items]    
Amortized Cost 251 1,254
Gross Unrealized Gains 3 3
Fair Value $ 254 $ 1,257