Stock Option Plans (Narrative) (Details) (USD $)	12 Months Ended
	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2009
Performance award expense			$ (1,221,000)
Pretax compensation expense associated with stock options	6,500,000	6,900,000	4,100,000
Tax benefit from stock options	2,400,000	2,500,000	1,500,000
Weighted average fair value for options granted, per share	$ 17.26	$ 13.23	$ 8.56
Intrinsic value of options exercised	34,200,000	19,500,000	9,100,000
Shares reserved for outstanding options and future grants	8,307,431
Shares added to the shares reserve for outstanding options and future grants	4,600,000
Aggregate intrinsic value of shares outstanding	85,000,000
Aggregate intrinsic value of shares exercisable	81,900,000
Total fair value of shares vested	10,500,000	8,000,000	7,900,000
Unrecognized compensation cost related to non-vested stock options granted	6,100,000
2010 Master Stock Incentive Plan [Member]
Options exercisable from the date of grant, in years	10
Performance award expense	1,800,000	500,000	3,100,000
Long-Term Compensation Plan [Member]
Reversal of Long-Term Compensation Plan expense			$ 3,600,000
Fiscal 2001 To Fiscal 2011 [Member]
Vesting period, years	three
Fiscal 2004, 2006 and 2007 [Member]
Vesting period, years	three