Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Additional Information (Detail)

v3.19.2
Fair Value Measurements - Additional Information (Detail)
Jul. 31, 2019
USD ($)
Fair Value Measurements Disclosure [Line Items]  
Marketable securities fair value, mature between one and three years $ 3,800,000
Fair Value, Inputs, Level 3 [Member]  
Fair Value Measurements Disclosure [Line Items]  
Fair value measurements of our financial assets $ 0