Stock Option Plans (Narrative) (Details) (USD $)	12 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance	3 years
Performance award expense	$ (1,296,000)	$ (10,000)
Pretax compensation expense associated with stock options	8,300,000	7,800,000	6,500,000
Tax benefit associated with stock options	2,700,000	2,500,000	2,100,000
Weighted average fair value for options granted, per share	$ 8.18	$ 9.37	$ 8.63
Total intrinsic value of options exercised	33,700,000	29,500,000	34,200,000
Shares reserved	13,656,154
Aggregate intrinsic value of options outstanding	90,700,000
Aggregate intrinsic value of options exercisable	85,400,000
Total fair value of shares vested	29,800,000	19,500,000	10,500,000
Unrecognized compensation expense related to non-vested stock options granted	7,500,000
2010 Master Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance award expense	$ 100,000	$ 1,900,000	$ 1,800,000
Fiscal 2002 To Fiscal 2013 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period, years	3 years
After Fiscal 2010 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period, years	3 years
Fiscal 2004, 2006, And 2007 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period, years	3 years
Maximum [Member] | 2010 Master Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options exercisable from date of the grant, in years	10 years