Liabilities and Restructuring Charges - Additional Information (Details) - USD ($)	3 Months Ended		12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Oct. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring	$ (35,000)	$ (282,000)
Employee Severance and Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring			$ 12,900,000
Cash payments	6,800,000
Employee related restructuring liabilities	$ 1,300,000.0		$ 8,100,000.0