Segment Reporting (Net Sales By Product Within Engine Products Segment And Industrial Products Segment) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Segment Reporting Information [Line Items]
Net sales	$ 660.1	$ 608.2	$ 550.6	$ 553.0	$ 593.8	$ 571.3	$ 517.2	$ 538.0	$ 2,371.9	$ 2,220.3	$ 2,371.2
Engine Products
Segment Reporting Information [Line Items]
Net sales									1,553.3	1,391.3	1,484.1
Engine Products | Off-Road
Segment Reporting Information [Line Items]
Net sales									252.1	216.6	261.1
Engine Products | On-Road
Segment Reporting Information [Line Items]
Net sales									110.7	127.2	138.4
Engine Products | Aftermarket
Segment Reporting Information [Line Items]
Net sales									1,086.2	951.5	980.7
Engine Products | Aerospace and Defense
Segment Reporting Information [Line Items]
Net sales									104.3	96.0	103.9
Industrial Products
Segment Reporting Information [Line Items]
Net sales									818.6	829.0	887.1
Industrial Products | Industrial Filtration Solutions
Segment Reporting Information [Line Items]
Net sales									533.2	517.9	529.0
Industrial Products | Gas Turbine Systems
Segment Reporting Information [Line Items]
Net sales									122.9	149.6	186.9
Industrial Products | Special Applications
Segment Reporting Information [Line Items]
Net sales									$ 162.5	$ 161.5	$ 171.2