Restructuring Charges (Details) - USD ($)	12 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 0	$ 16,100,000	$ 16,900,000
Expense related to lump sum settlement			3,900,000
Restructuring liability		0
Operating expenses
Restructuring Cost and Reserve [Line Items]
Restructuring charges		10,400,000	8,500,000
Cost of sales
Restructuring Cost and Reserve [Line Items]
Restructuring charges		5,700,000	8,400,000
Engine Products
Restructuring Cost and Reserve [Line Items]
Restructuring charges		8,800,000	9,200,000
Industrial Products
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 7,300,000	$ 3,800,000