v3.20.4
Inventory - Additional Information (Detail) - USD ($)
1 Months Ended 3 Months Ended 9 Months Ended
Feb. 01, 2020
Oct. 31, 2020
Sep. 30, 2019
Oct. 31, 2020
Sep. 30, 2019
Inventory Disclosure [Abstract]          
Inventory net of write-downs $ 41,000 $ 159,000 $ 7,000 $ 260,000 $ 87,000