Stock-Based Compensation Stock Options (Details) (USD $)	12 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2011
Additional Disclosures
Targeted annual dividend per share	$ 1.10	$ 1.10	$ 1.00
Stock options and SARs [Member]
Awards (In Shares)
Outstanding, Beginning Balance	3,458,403	3,580,168	3,520,667
Granted	296,525	423,528	680,750
Expired/canceled	(616,135)	(390,148)	(481,364)
Exercised	(90,883)	(155,145)	(139,885)
Outstanding, Ending Balance	3,047,910	3,458,403	3,580,168
Exercisable, Ending Balance	1,896,030
Vested and Expected to Vest, Ending Balance	2,945,608
Weighted Average Exercise Price (Per Share)
Outstanding, Beginning Balance	$ 31.61	$ 31.86	$ 32.75
Granted	$ 26.07	$ 29.24	$ 27.64
Expired/canceled	$ 39.96	$ 35.71	$ 35.79
Exercised	$ 13.01	$ 20.64	$ 20.29
Outstanding, Ending Balance	$ 29.94	$ 31.61	$ 31.86
Exercisable, Ending Balance	$ 31.18
Vested and Expected to Vest, Ending Balance	$ 30.00
Weighted Average Remaining Contractual Term (Years)
Outstanding, Ending Balance	4 years 9 months 26 days
Exercisable, Ending Balance	2 years 8 months 23 days
Vested And Expected To Vest, Ending Balance	4 years 8 months 12 days
Aggregated Intrinsic Value
Outstanding, Ending Balance	$ 2,198,000
Exercisable, Ending Balance	1,895,000
Vested and Expected to Vest, Ending Balance	2,182,000
Additional Disclosures
Exercise price, lower range limit	$ 11.67
Exercise price, upper range limit	$ 48.89
Total intrinsic value of stock-based awards exercised	$ 1,272,000	$ 1,654,000	$ 1,177,000
Stock Options [Member]
Additional Disclosures
Per share weighted average grant date fair value of stock based awards granted	$ 4.45	$ 6.53	$ 6.51
Fair Value Assumptions
Expected dividend yield	4.22%	3.76%	3.62%
Expected volatility	30.09%	36.63%	36.31%
Risk-free interest rate	1.02%	0.64%	1.58%
Expected life (in years)	5 years 4 months 21 days	5 years 3 months 15 days	5 years 1 month 6 days
Stock Options [Member] | Stock-based Awards with Five Year Contractual Term [Member]
Additional Disclosures
Contractual term (in years)	5 years	5 years	5 years
Vesting period (in years)	3 years	3 years	3 years
Stock Options [Member] | Stock-based Awards with Ten Year Contractual Term [Member]
Additional Disclosures
Contractual term (in years)	10 years	10 years	10 years
Vesting period (in years)	5 years	5 years	5 years