Stock-Based Compensation Stock Options (Details) - USD ($)	12 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2013
Additional Disclosures
Targeted annual dividend per share	$ 1.20	$ 1.20	$ 1.10
Stock options [Member]
Additional Disclosures
Exercise price, lower range limit	24.35
Exercise price, upper range limit	$ 33.94
Total intrinsic value relating to stock-based awards exercised during the period	$ 2,279,000	$ 6,464,000	$ 1,272,000
Vested stock-based awards net settled upon exercise (in shares)	333,338	618,970
Common stock issued for net settlement of stock-based awards (in shares)	49,086	79,890	0
Per share weighted average grant date fair value of stock based awards granted	$ 6.12	$ 5.35	$ 4.45
Fair Value Assumptions
Expected dividend yield	3.55%	3.94%	4.22%
Expected volatility	28.19%	30.36%	30.09%
Risk-free interest rate	1.61%	1.47%	1.02%
Expected life (years)	5 years 5 months 9 days	5 years 3 months 26 days	5 years 4 months 21 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
Stock appreciation rights (SARs) [Member]
Awards (In Shares)
Granted	0	0	0
Exercised	0	(7,000)	0
Stock Options (Including SARs) [Member]
Awards (In Shares)
Outstanding, Beginning Balance	2,132,896	3,047,910	3,458,403
Granted	416,525	458,110	296,525
Expired/canceled	(46,400)	(492,060)	(616,135)
Exercised	(383,338)	(881,064)	(90,883)
Outstanding, Ending Balance	2,119,683	2,132,896	3,047,910
Exercisable, Ending Balance	963,625
Vested and Expected to Vest, Ending Balance	1,901,782
Weighted Average Exercise Price (Per Share)
Outstanding, Beginning Balance	$ 28.17	$ 29.94	$ 31.61
Granted	33.78	29.14	26.07
Expired/canceled	30.20	42.90	39.96
Exercised	27.61	26.55	13.01
Outstanding, Ending Balance	29.33	$ 28.17	$ 29.94
Exercisable, Ending Balance	28.27
Vested and Expected to Vest, Ending Balance	$ 29.27
Weighted Average Remaining Contractual Term (Years)
Outstanding, Ending Balance	6 years 11 months 28 days
Exercisable, Ending Balance	5 years 7 months 15 days
Vested And Expected To Vest, Ending Balance	6 years 10 months 19 days
Aggregated Intrinsic Value
Outstanding, Ending Balance	$ 1,638,000
Exercisable, Ending Balance	744,000
Vested and Expected to Vest, Ending Balance	$ 1,436,000