Stock-Based Compensation Performance Shares, RSUs, Restricted Stock and Share Unit Awards (Details) (USD $)			3 Months Ended
	Oct. 31, 2013	Jul. 31, 2013	Oct. 31, 2013 Performance Shares, RSUs, Restricted Stock and Share Units	Oct. 31, 2013 Performance Shares Granted prior to fiscal 2014	Oct. 31, 2013 Performance Shares Granted during the three months ended October 31, 2013	Oct. 31, 2013 Performance Shares Granted in fiscal 2012	Oct. 31, 2013 RSUs and restricted stock Non-Employee Director [Member]	Oct. 31, 2013 RSUs and restricted stock Employees [Member]	Oct. 31, 2013 Dividend Equivalents	Jul. 31, 2013 Dividend Equivalents
Awards (in Shares)
Outstanding, Beginning Balance			102,334
Granted			68,167			35,003
Converted to common stock			(4,509)
Outstanding, Ending Balance			165,992
Vested, Ending Balance			12,335
Vested and Expected to Vest, Ending Balance			158,953
Weighted Average Grant Date Fair Value
Outstanding, Beginning Balance			$ 25.80
Granted			$ 24.58
Converted to common stock			$ 26.25
Outstanding, Ending Balance			$ 25.28
Vested, Ending Balance			$ 26.84
Vested and Expected to Vest, Ending Balance			$ 25.29
Aggregate Intrinsic Value
Outstanding, Ending Balance			$ 4,983,000
Vested, Ending Balance			370,000
Vested and Expected to Vest, Ending Balance			4,772,000
Additional Disclosures
Vesting period (in years)				5 years 3 months 19 days	3 years		3 years	5 years
Performance period (in years)					3 years
Granted			68,167			35,003
Vested						6,996
Converted into common stock, net of reduction of shares for minimum tax withholding and deferral requirements						3,496
Reduction of shares retained to satisfy minimum tax withholding						1,013
Reduction of shares retained for deferral requirements						2,487
Accrued at period end	$ 281,908,000	$ 277,753,000							$ 32,000	$ 7,000