Stock-Based Compensation - Stock Options (Details) (USD $)	3 Months Ended				9 Months Ended
	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Apr. 30, 2014	Apr. 30, 2015	Apr. 30, 2014
Additional Disclosures
Targeted annual dividend per share (in dollars per share)	$ 1.20				$ 1.20
Stock Options
Awards (in Shares)
Outstanding, Beginning Balance (in shares)	2,234,733	2,229,033	2,132,896		2,132,896
Granted (in shares)	3,000	154,025	253,000
Expired/canceled (in shares)	(14,600)	(10,800)	(9,900)
Exercised (in shares)	(58,700)	(137,525)	(146,963)
Outstanding, Ending Balance (in shares)	2,164,433	2,234,733	2,229,033		2,164,433
Exercisable, Ending Balance (in shares)	671,335				671,335
Vested and Expected to Vest, Ending Balance (in shares)	2,021,995				2,021,995
Weighted Average Exercise Price
Outstanding, Beginning Balance (in dollars per share)	$ 29.32	$ 28.94	$ 28.17		$ 28.17
Granted (in dollars per share)	$ 29.31	$ 33.76	$ 33.94
Expired/canceled (in dollars per share)	$ 32.71	$ 29.20	$ 29.10
Exercised (in dollars per share)	$ 28.80	$ 28.06	$ 26.43
Outstanding, Ending Balance (in dollars per share)	$ 29.31	$ 29.32	$ 28.94		$ 29.31
Exercisable, Ending Balance (in dollars per share)	$ 28.20				$ 28.20
Vested and Expected to Vest, Ending Balance (in dollars per share)	$ 29.30				$ 29.30
Weighted Average Remaining Contractual Term (Years)
Outstanding, Ending Balance					7 years 1 month 17 days
Exercisable, Ending Balance					5 years 3 months 11 days
Vested And Expected To Vest, Ending Balance					7 years 1 month 2 days
Aggregate Intrinsic Value
Outstanding, Ending Balance	$ 1,763,000				$ 1,763,000
Exercisable, Ending Balance	537,000				537,000
Vested and Expected to Vest, Ending Balance	1,621,000				1,621,000
Additional Disclosures
Exercise price, lower range limit (in dollars per share)					$ 24.35
Exercise price, upper range limit (in dollars per share)					$ 33.94
Total intrinsic value of stock-based awards settled	$ 265,000			$ 533,000	$ 2,224,000	$ 965,000
Contractual term (in years)					10 years	10 years
Vesting period (in years)					5 years	5 years
Vested Stock Based Awards Net Settled Upon Exercise (in shares)					293,988	88,755
Stock Issued During The Period, Shares, Net Settlement Of Stock-Based Awards					47,532	5,488
Per share weighted average grant date fair value of stock based awards granted (in dollars per share)	$ 4.53			$ 5.91	$ 6.13	$ 5.51
Fair Value Assumptions
Expected dividend yield	4.09%			3.98%	3.55%	4.03%
Expected volatility	27.00%			32.00%	28.12%	32.83%
Risk-free interest rate	1.37%			1.49%	1.61%	1.39%
Expected life (years)	5 years 2 months 19 days			5 years 3 months 22 days	5 years 5 months 12 days	5 years 5 months 5 days
SARs
Awards (in Shares)
Granted (in shares)	0			0	0	0
Exercised (in shares)	0			0	0	0