Stockholder's Investment (Details 3) (USD $)	12 Months Ended
	Jul. 31, 2011 Year	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2009	Jul. 31, 2008
Schedule of Stock Options Outstanding
Options Outstanding, Beginning Balance	5,108,736	5,726,017		3,980,606	3,985,205
Option Outstanding Weighted Average Remaining Contractual Life	6.4
Options Outstanding, Weighted Average Exercise Price	$ 29.24		$ 28.69	$ 27.96	$ 29.43
Options exercisable with weighted average, shares	3,316,815		3,100,955	2,831,311
Options Exercisable, Weighted Average Exercise Price	$ 29.83		$ 28.85	$ 27.46
Up to $14.99 [Member]
Schedule of Stock Options Outstanding
Option Price, Upper Range	$ 14.99
Options Outstanding, Beginning Balance		200,000
Option Outstanding Weighted Average Remaining Contractual Life	1.6
Options Outstanding, Weighted Average Exercise Price	$ 13.31
Options exercisable with weighted average, shares	200,000
Options Exercisable, Weighted Average Exercise Price	$ 13.31
$15.00 to $29.99 [Member]
Schedule of Stock Options Outstanding
Option Price, Lower Range	$ 15.00
Option Price, Upper Range	$ 29.99
Options Outstanding, Beginning Balance		3,900,515
Option Outstanding Weighted Average Remaining Contractual Life	7.2
Options Outstanding, Weighted Average Exercise Price	$ 26.68
Options exercisable with weighted average, shares	1,516,313
Options Exercisable, Weighted Average Exercise Price	$ 24.07
$30.00 and up [Member]
Schedule of Stock Options Outstanding
Option Price, Lower Range	$ 30.00
Options Outstanding, Beginning Balance		1,625,502
Option Outstanding Weighted Average Remaining Contractual Life	5.0
Options Outstanding, Weighted Average Exercise Price	$ 37.33
Options exercisable with weighted average, shares	1,600,502
Options Exercisable, Weighted Average Exercise Price	$ 37.34