Restructuring Provision - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jul. 31, 2020	Jul. 31, 2020
Restructuring Cost And Reserve [Line Items]
Restructuring charges	$ 8.0
Restructuring charges with non-cash use	$ 6.6
Write-off related to non-refundable deposits		$ 1.5
Severance and Employee Related | Minimum
Restructuring Cost And Reserve [Line Items]
Expected annual savings from restructuring plan		14.0
Severance and Employee Related | Maximum
Restructuring Cost And Reserve [Line Items]
Expected annual savings from restructuring plan		$ 16.0