Quarterly report pursuant to Section 13 or 15(d)

Severance and Other Restructuring Costs - Additional Information (Detail)

v3.8.0.1
Severance and Other Restructuring Costs - Additional Information (Detail)
$ in Millions
3 Months Ended 21 Months Ended
Apr. 30, 2018
USD ($)
Employee
Apr. 30, 2018
USD ($)
Restructuring Cost and Reserve [Line Items]    
Additional severance charges $ 0.1  
Number of employees terminated | Employee 4  
Restructuring Plan [Member]    
Restructuring Cost and Reserve [Line Items]    
Total restructuring charges incurred   $ 7.1