Segment Information (Details 1) (USD $) In Thousands	3 Months Ended								12 Months Ended
	Jul. 31, 2011	Apr. 30, 2011	Jan. 31, 2011	Oct. 31, 2010	Jul. 31, 2010	Apr. 30, 2010	Jan. 31, 2010	Oct. 31, 2009	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2009
Net income reconciliation:
Total profit for reportable segments									$ 307,668	$ 280,590	$ 256,854
Corporate and eliminations									291,926	266,459	248,902
Unallocated amounts:
Administrative costs									(120,546)	(121,689)	(102,680)
Restructuring costs	(2,202)	(1,211)	(2,134)	(3,641)	(5,717)	(2,347)	(3,649)	(3,601)	(9,188)	(15,314)	(25,849)
Investment and other income - net									3,990	1,168	1,800
Interest expense									(22,124)	(21,222)	(24,901)
Income before income taxes									144,058	109,402	97,272
Income taxes									(35,406)	(27,446)	(27,150)
Net income	29,583	28,589	24,199	26,281	21,592	23,695	15,001	21,668	108,652	81,956	70,122
Corporate and Eliminations [Member]
Net income reconciliation:
Corporate and eliminations									$ (15,742)	$ (14,131)	$ (7,952)