Segment Reporting (Net Sales By Product Within Engine Products Segment And Industrial Products Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2014		Jul. 31, 2013		Jul. 31, 2012
Segment Reporting Information [Line Items]
Net sales	$ 668,226	$ 624,234	$ 581,622	$ 599,384	$ 632,594	$ 619,371	$ 596,036	$ 588,947	$ 2,473,466		$ 2,436,948		$ 2,493,248
Engine Products [Member]
Segment Reporting Information [Line Items]
Net sales									1,584,027		1,504,188		1,570,140
Industrial Products [Member]
Segment Reporting Information [Line Items]
Net sales									889,439		932,760		923,108
Off-Road Products [Member] | Engine Products [Member]
Segment Reporting Information [Line Items]
Net sales									342,205		358,834		376,870
On-Road Products [Member] | Engine Products [Member]
Segment Reporting Information [Line Items]
Net sales									130,029		128,446		163,934
Aftermarket Products [Member] | Engine Products [Member]
Segment Reporting Information [Line Items]
Net sales									1,012,165	[1]	912,717	[1]	922,660	[1]
Aerospace and Defense Products [Member] | Engine Products [Member]
Segment Reporting Information [Line Items]
Net sales									99,628		104,191		106,676
Industrial Filtration Solutions Products [Member] | Industrial Products [Member]
Segment Reporting Information [Line Items]
Net sales									553,356		529,751		553,453
Gas Turbine Products [Member] | Industrial Products [Member]
Segment Reporting Information [Line Items]
Net sales									156,860		232,922		180,669
Special Applications Products [Member] | Industrial Products [Member]
Segment Reporting Information [Line Items]
Net sales									$ 179,223		$ 170,087		$ 188,986

[1] Includes replacement part sales to the Company’s OEM Customers.