Inventories (Details) (USD $)	Jan. 31, 2012	Jul. 31, 2011
Inventories [Abstract]
Materials	$ 112,153,000	$ 110,466,000
Work in process	34,524,000	33,917,000
Finished products	123,535,000	127,093,000
Total inventories	270,212,000	271,476,000
Obsolete inventory reserves	$ 13,700,000	$ 14,500,000