Quarterly report pursuant to Section 13 or 15(d)

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

v3.20.1
Fair Value Measurements - Summary of Marketable Securities by Security Type (Detail) - USD ($)
$ in Thousands
Apr. 30, 2020
Jan. 31, 2020
Schedule Of Available For Sale Securities [Line Items]    
Amortized Cost $ 3,367 $ 4,564
Gross Unrealized Gains 63 53
Fair Value 3,430 4,617
U.S. Treasury Notes and Bonds [Member]    
Schedule Of Available For Sale Securities [Line Items]    
Amortized Cost 3,114 3,310
Gross Unrealized Gains 59 50
Fair Value 3,173 3,360
Corporate Bonds [Member]    
Schedule Of Available For Sale Securities [Line Items]    
Amortized Cost 253 1,254
Gross Unrealized Gains 4 3
Fair Value $ 257 $ 1,257