Annual report pursuant to Section 13 and 15(d)

Income Taxes - Income Tax (Benefit) Provision for Continuing Operations Computed Using Federal Statutory Income Tax Rate (Parenthetical) (Detail)

v3.19.1
Income Taxes - Income Tax (Benefit) Provision for Continuing Operations Computed Using Federal Statutory Income Tax Rate (Parenthetical) (Detail) - USD ($)
$ in Millions
12 Months Ended
Jan. 31, 2019
Jan. 31, 2018
Income Taxes Disclosure [Line Items]    
Income tax reconciliation other adjustments included in other non-deductible expenses $ 0.3  
Maximum [Member]    
Income Taxes Disclosure [Line Items]    
Income tax reconciliation other adjustments included in other non-deductible expenses   $ (0.1)