Sales and Major Customers - Additional Information (Detail) - person	12 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018
Segment Reporting [Abstract]
Number of customers with revenue exceeding 10% of total Company revenue	0	0	2
Percentage change in total revenues by one customer (as a percent)	10.00%	10.00%	10.00%