Segment Reporting (Summary Of Segment Detail) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2011
Segment Reporting Information [Line Items]
Net sales	$ 632,594	$ 619,371	$ 596,036	$ 588,947	$ 656,833	$ 647,237	$ 580,883	$ 608,295	$ 2,436,948	$ 2,493,248	$ 2,294,029
Depreciation and amortization									64,290	61,165	60,491
Equity earnings in unconsolidated affiliates									4,693	4,735	4,105
Earnings before income taxes									348,181	370,780	312,263
Assets	1,743,556				1,730,082				1,743,556	1,730,082	1,726,093
Equity investments in unconsolidated affiliates	18,840				20,126				18,840	20,126	19,177
Capital expenditures, net of acquired businesses									94,895	78,139	60,633
Engine Products [Member]
Segment Reporting Information [Line Items]
Net sales									1,504,188	1,570,140	1,440,495
Depreciation and amortization									35,815	36,646	36,338
Equity earnings in unconsolidated affiliates									4,000	3,966	3,302
Earnings before income taxes									220,892	227,941	211,255
Assets	826,151				845,176				826,151	845,176	888,080
Equity investments in unconsolidated affiliates	15,563				17,304				15,563	17,304	16,619
Capital expenditures, net of acquired businesses									52,864	46,816	36,423
Industrial Products [Member]
Segment Reporting Information [Line Items]
Net sales									932,760	923,108	853,534
Depreciation and amortization									22,447	18,852	19,396
Equity earnings in unconsolidated affiliates									693	769	803
Earnings before income taxes									139,108	149,249	123,871
Assets	527,416				520,739				527,416	520,739	519,730
Equity investments in unconsolidated affiliates	3,277				2,822				3,277	2,822	2,558
Capital expenditures, net of acquired businesses									33,134	24,083	19,442
Corporate & Unallocated [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization									6,028	5,667	4,757
Earnings before income taxes									(11,819)	(6,410)	(22,863)
Assets	389,989				364,167				389,989	364,167	318,283
Capital expenditures, net of acquired businesses									$ 8,897	$ 7,240	$ 4,768