Stock-Based Compensation Stock Options (Details) - USD ($)	12 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2014
Additional Disclosures
Targeted annual dividend per share (in dollars per share)	$ 1.20	$ 1.20	$ 1.10
Stock options [Member]
Additional Disclosures
Exercise price, lower range limit (in dollars per share)	12.43
Exercise price, upper range limit (in dollars per share)	$ 33.94
Total intrinsic value relating to stock-based awards exercised during the period	$ 32,000	$ 2,279,000	$ 6,464,000
Vested stock-based awards net settled upon exercise (in shares)	19,200	333,338	618,970
Common stock issued for net settlement of stock-based awards (in shares)	706	49,086	79,890
Per share weighted average grant date fair value of stock based awards granted (in dollars per share)	$ 5.50	$ 6.12	$ 5.35
Fair Value Assumptions
Expected dividend yield	4.46%	3.55%	3.94%
Expected volatility	34.44%	28.19%	30.36%
Risk-free interest rate	1.52%	1.61%	1.47%
Expected life (years)	5 years 1 month 24 days	5 years 5 months 9 days	5 years 3 months 26 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 (in shares)	0	0	0
Exercised (in shares)	0	0	(7,000)
Stock Options (Including SARs) [Member]
Awards (In Shares)
Outstanding, Beginning Balance (in shares)	2,119,683	2,132,896	3,047,910
Granted (in shares)	552,806	416,525	458,110
Expired/canceled (in shares)	(396,610)	(46,400)	(492,060)
Exercised (in shares)	(19,200)	(383,338)	(881,064)
Outstanding, Ending Balance (in shares)	2,256,679	2,119,683	2,132,896
Exercisable, Ending Balance (in shares)	1,154,882
Vested and Expected to Vest, Ending Balance (in shares)	2,174,225
Weighted Average Exercise Price (Per Share)
Outstanding, Beginning Balance (in dollars per share)	$ 29.33	$ 28.17	$ 29.94
Granted (in dollars per share)	27.15	33.78	29.14
Expired/canceled (in dollars per share)	28.99	30.20	42.90
Exercised (in shares)	27.24	27.61	26.55
Outstanding, Ending Balance (in dollars per share)	28.87	$ 29.33	$ 28.17
Exercisable, Ending Balance (in dollars per share)	28.60
Vested and Expected to Vest, Ending Balance (in dollars per share)	$ 28.86
Weighted Average Remaining Contractual Term (Years)
Outstanding, Ending Balance	6 years 8 months 1 day
Exercisable, Ending Balance	5 years 4 months 30 days
Vested And Expected To Vest, Ending Balance	6 years 7 months 13 days
Aggregated Intrinsic Value
Outstanding, Ending Balance	$ 1,000
Exercisable, Ending Balance	0
Vested and Expected to Vest, Ending Balance	$ 1,000