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, 2016	Jul. 31, 2015	Jul. 31, 2014
Segment Reporting Information [Line Items]
Net sales	$ 593.8	$ 571.3	$ 517.2	$ 538.0	$ 610.6	$ 575.6	$ 588.5	$ 596.5	$ 2,220.3	$ 2,371.2	$ 2,473.5
Depreciation and amortization									74.9	74.3	67.2
Income (Loss) from Equity Method Investments									2.2	5.1	6.5
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest									257.4	288.6	360.7
Assets	1,788.6				1,809.5				1,788.6	1,809.5	1,942.4
Investments in and Advances to Affiliates, Amount of Equity	18.7				18.3				18.7	18.3	21.4
Payments to Acquire Property, Plant, and Equipment									72.9	93.8	97.2
Engine Products
Segment Reporting Information [Line Items]
Net sales									1,391.3	1,484.1	1,584.0
Depreciation and amortization									38.5	43.3	38.9
Income (Loss) from Equity Method Investments									1.0	4.1	5.6
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest									163.5	186.3	233.9
Assets	841.4				887.7				841.4	887.7	900.1
Investments in and Advances to Affiliates, Amount of Equity	14.3				15.1				14.3	15.1	17.4
Payments to Acquire Property, Plant, and Equipment									37.5	54.6	56.3
Industrial Products
Segment Reporting Information [Line Items]
Net sales									829.0	887.1	889.5
Depreciation and amortization									28.1	26.4	24.0
Income (Loss) from Equity Method Investments									1.2	1.0	0.9
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest									119.0	123.3	134.0
Assets	646.9				634.0				646.9	634.0	572.0
Investments in and Advances to Affiliates, Amount of Equity	4.4				3.2				4.4	3.2	4.0
Payments to Acquire Property, Plant, and Equipment									27.3	33.4	34.7
Corporate And Unallocated
Segment Reporting Information [Line Items]
Depreciation and amortization									8.3	4.6	4.3
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest									(25.1)	(21.0)	(7.2)
Assets	$ 300.3				$ 287.8				300.3	287.8	470.3
Payments to Acquire Property, Plant, and Equipment									8.1	5.8	6.2
Domestic Tax Authority
Segment Reporting Information [Line Items]
Net sales									937.3	1,007.3	1,019.9
Aerospace And Defense Products | Engine Products
Segment Reporting Information [Line Items]
Net sales									96.0	103.9	99.6
Aftermarket Products | Engine Products
Segment Reporting Information [Line Items]
Net sales									951.5	980.7	1,012.2
Off Road Products | Engine Products
Segment Reporting Information [Line Items]
Net sales									216.6	261.1	342.2
On Road Products | Engine Products
Segment Reporting Information [Line Items]
Net sales									127.2	138.4	130.0
Gas Turbine Products | Industrial Products
Segment Reporting Information [Line Items]
Net sales									149.6	186.9	156.9
Industrial Filtration Solutions Products | Industrial Products
Segment Reporting Information [Line Items]
Net sales									517.9	529.0	553.4
Special Applications Products | Industrial Products
Segment Reporting Information [Line Items]
Net sales									$ 161.5	$ 171.2	$ 179.2