Stock Compensation Plan (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended													12 Months Ended
	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2012 Stock Appreciation Rights (SARs) [Member]	Jul. 31, 2011 Stock Appreciation Rights (SARs) [Member]	Jul. 31, 2010 Stock Appreciation Rights (SARs) [Member]	Jul. 31, 2012 Restricted Stock Units (RSUs) [Member]	Jul. 31, 2011 Restricted Stock Units (RSUs) [Member]	Jul. 31, 2010 Restricted Stock Units (RSUs) [Member]	Jul. 31, 2012 Scenario, Forecast [Member]	Jul. 31, 2013 Expected to be Recognized in 2011 [Member] Scenario, Forecast [Member]	Jul. 31, 2014 Expected to be Recognized in 2012 [Member] Scenario, Forecast [Member]	Jul. 31, 2015 Expected to be Recognized in 2013 [Member] Scenario, Forecast [Member]	Jul. 31, 2012 Maximum [Member]	Jul. 31, 2012 Minimum [Member]
Shares issued for stock based compensation (in shares)	7,500,000
Stock based compensation award life	10 years
Stock based compensation award vesting period	3 years
Stock based compensation, shares available for grant (in shares)	2,800,000
Stock based compensation, estimated forfeiture rates														20.80%	15.50%
Weighted-average grant-date fair value (in dollars per share)				$ 12.71	$ 13.84	$ 13.70	$ 38.15	$ 37.03	$ 36.11
Intrinsic value of options and SARs exercised				$ 1.3	$ 2.0	$ 0.7
Options and SARs that vested during the period (in shares)				930,000	288,000	241,000
Total fair value of options vested during the period				10.7	0.7	0.6
Stock based compensation, restricted shares granted (in shares)							180,000	201,000	136,000
Stock based compensation, restricted shares vested (in shares)							234,000	143,000	135,000
Stock based compensation, total fair value of restricted shares							9.2	5.9	4.9
Total unrecognized compensation expense										14.6	8.7	5.2	0.8
Cash received from exercise of stock option	0.5	1.1	0.5
Tax benefit from exercise of stock options	$ 3.9	$ 2.5	$ 2.1