Segment Reporting (Summary Of Segment Detail) (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 6 Months Ended
Jan. 31, 2015
Jan. 31, 2014
Jan. 31, 2015
Jan. 31, 2014
Jul. 31, 2014
Segment Reporting Information [Line Items]          
Net sales $ 596,944 $ 581,622 $ 1,193,454 $ 1,181,006  
Earnings before income taxes 67,811 74,882 145,094 165,669  
Assets 1,850,250 1,773,543 1,850,250 1,773,543 1,942,411
Engine Products [Member]          
Segment Reporting Information [Line Items]          
Net sales 357,109 369,675 747,829 758,791  
Earnings before income taxes 41,436 47,294 94,596 109,367  
Assets 873,310 836,585 873,310 836,585  
Industrial Products [Member]          
Segment Reporting Information [Line Items]          
Net sales 239,835 211,947 445,625 422,215  
Earnings before income taxes 37,446 28,032 65,089 59,175  
Assets 639,890 522,062 639,890 522,062  
Corporate & Unallocated [Member]          
Segment Reporting Information [Line Items]          
Earnings before income taxes (11,071) (444) (14,591) (2,873)  
Assets $ 337,050 $ 414,896 $ 337,050 $ 414,896