Segment Reporting (Summary Of Segment Detail) (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
Depreciation and amortization									67,163	64,290	61,165
Equity earnings in unconsolidated affiliates									6,536	4,693	4,735
Earnings before income taxes									360,703	348,181	370,780
Assets	1,942,411				1,743,556				1,942,411	1,743,556	1,730,082
Equity investments in unconsolidated affiliates	21,398				18,840				21,398	18,840	20,126
Capital expenditures									97,210	94,895	78,139
Engine Products [Member]
Segment Reporting Information [Line Items]
Net sales									1,584,027	1,504,188	1,570,140
Depreciation and amortization									38,925	35,815	36,646
Equity earnings in unconsolidated affiliates									5,596	4,000	3,966
Earnings before income taxes									233,920	220,892	227,941
Assets	900,083				826,151				900,083	826,151	845,176
Equity investments in unconsolidated affiliates	17,439				15,563				17,439	15,563	17,304
Capital expenditures									56,340	52,864	46,816
Industrial Products [Member]
Segment Reporting Information [Line Items]
Net sales									889,439	932,760	923,108
Depreciation and amortization									23,942	22,447	18,852
Equity earnings in unconsolidated affiliates									940	693	769
Earnings before income taxes									133,978	139,108	149,249
Assets	572,000				527,416				572,000	527,416	520,739
Equity investments in unconsolidated affiliates	3,959				3,277				3,959	3,277	2,822
Capital expenditures									34,652	33,134	24,083
Corporate & Unallocated [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization									4,296	6,028	5,667
Earnings before income taxes									(7,195)	(11,819)	(6,410)
Assets	470,328				389,989				470,328	389,989	364,167
Capital expenditures									$ 6,218	$ 8,897	$ 7,240