Segment Reporting (Summary Of Segment Detail) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Apr. 30, 2012	Apr. 30, 2011	Apr. 30, 2012	Apr. 30, 2011	Jul. 31, 2011
Segment Reporting Information [Line Items]
Net sales	$ 647,237	$ 594,565	$ 1,836,415	$ 1,668,579
Earnings before income taxes	99,990	81,816	268,426	221,780
Assets	1,754,273	1,741,807	1,754,273	1,741,807	1,726,093
Engine Products [Member]
Segment Reporting Information [Line Items]
Net sales	407,041	377,609	1,171,600	1,042,500
Earnings before income taxes	62,136	56,469	170,432	149,123
Assets	879,228	843,450	879,228	843,450
Industrial Products [Member]
Segment Reporting Information [Line Items]
Net sales	240,196	216,956	664,815	626,079
Earnings before income taxes	38,792	33,074	103,688	92,236
Assets	534,686	503,962	534,686	503,962
Corporate & Unallocated [Member]
Segment Reporting Information [Line Items]
Earnings before income taxes	(938)	(7,727)	(5,694)	(19,579)
Assets	$ 340,359	$ 394,395	$ 340,359	$ 394,395