Revenue Recognition (Narrative) (Details) $ in Millions	Apr. 30, 2019 USD ($)
Revenue from Contract with Customer [Abstract]
Remaining performance obligation	$ 2,740.0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-05-01
Revenue from Contract with Customer [Abstract]
Remaining performance obligation	$ 2,000.0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation percentage	73.00%
Performance obligation, expected timing of satisfaction	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-05-01
Revenue from Contract with Customer [Abstract]
Remaining performance obligation	$ 744.5
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation percentage	27.00%
Performance obligation, expected timing of satisfaction