Revenue from Contracts with Customers - Remaining Performance Obligations (Details) $ in Millions	Apr. 30, 2020 USD ($)
Revenue from Contract with Customer [Abstract]
Revenue, remaining performance obligation, amount	$ 827.8
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-05-01
Revenue from Contract with Customer [Abstract]
Revenue, remaining performance obligation, amount	$ 554.7
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognition period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-02-01
Revenue from Contract with Customer [Abstract]
Revenue, remaining performance obligation, amount	$ 273.1
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognition period