Revenue (Disaggregation of Revenue by Segment) (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2017
Disaggregation of Revenue [Line Items]
Net sales	$ 2,844.9	$ 2,734.2	$ 2,371.9
Engine Products
Disaggregation of Revenue [Line Items]
Net sales	1,926.0	1,849.0	1,553.3
Engine Products | Off-Road
Disaggregation of Revenue [Line Items]
Net sales	315.1	327.4	252.1
Engine Products | On-Road
Disaggregation of Revenue [Line Items]
Net sales	179.8	154.2	110.7
Engine Products | Aftermarket
Disaggregation of Revenue [Line Items]
Net sales	1,315.3	1,261.9	1,086.2
Engine Products | Aerospace and Defense
Disaggregation of Revenue [Line Items]
Net sales	115.8	105.5	104.3
Industrial Products
Disaggregation of Revenue [Line Items]
Net sales	918.9	885.2	818.6
Industrial Products | Industrial Filtration Solutions
Disaggregation of Revenue [Line Items]
Net sales	641.8	594.3	533.2
Industrial Products | Gas Turbine Systems
Disaggregation of Revenue [Line Items]
Net sales	106.3	115.5	122.9
Industrial Products | Special Applications
Disaggregation of Revenue [Line Items]
Net sales	$ 170.8	$ 175.4	$ 162.5