Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans - Additional Information (Detail)

v3.8.0.1
Employee Benefit Plans - Additional Information (Detail) - USD ($)
12 Months Ended
Jan. 31, 2018
Jan. 31, 2017
Jan. 31, 2016
Pension Plans, Postretirement and Other Employee Benefits [Line Items]      
Pension benefit obligation balance $ 0 $ 530,000 $ 1,063,000
Retirement Savings Plan [Member]      
Pension Plans, Postretirement and Other Employee Benefits [Line Items]      
Defined contribution plan, cost recognized $ 1,100,000 $ 1,400,000 $ 1,500,000