Segment Information (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2011	Apr. 30, 2011	Jan. 31, 2011	Oct. 31, 2010	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2010
Net income reconciliation
Total profit from reportable segments									$ 293,004	$ 307,668	$ 280,590
Unallocated amounts:
Administrative costs									(118,120)	(120,546)	(121,689)
Restructuring charges	(8,670)	(3,440)			(2,202)	(1,211)	(2,134)	(3,641)	(12,110)	(9,188)	(15,314)
Impairment charge			(115,688)						(115,688)
Investment and other income - net									2,082	3,990	1,168
Interest expense									(19,090)	(22,124)	(21,222)
Income before income taxes									22,750	144,058	109,402
Income taxes									(40,661)	(35,406)	(27,446)
Net (loss) income	11,659	27,652	(89,954,000)	32,732	29,583	28,589	24,199	26,281	(17,911)	108,652	81,956
Corporate and Eliminations [Member]
Net income reconciliation
Corporate and eliminations									$ (7,328)	$ (15,742)	$ (14,131)