Stock-Based Compensation Performance Shares, RSUs, Restricted Stock and Share Unit Awards (Details) (USD $)	12 Months Ended		12 Months Ended		0 Months Ended	12 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014 Performance Shares, RSUs, Restricted Stock and Share Units [Member]	Jul. 31, 2013 Performance Shares, RSUs, Restricted Stock and Share Units [Member]	Sep. 23, 2014 Performance Shares [Member] Subsequent Event [Member]	Jul. 31, 2014 Performance Shares [Member] Employees [Member] Granted prior to fiscal 2014 [Member]	Jul. 31, 2014 Performance Shares [Member] Employees [Member] Granted during the period [Member]	Jul. 31, 2014 RSUs and restricted stock [Member] Non-Employee Director [Member]	Jul. 31, 2014 RSUs and restricted stock [Member] Employees [Member]	Jul. 31, 2014 Dividend Equivalents [Member]	Jul. 31, 2013 Dividend Equivalents [Member]
Awards (In Shares)
Outstanding, Beginning Balance			102,334	48,081
Granted			95,326	54,253
Converted to common stock			(7,857)
Forfeited			(9,706)
Outstanding, Ending Balance			180,097	102,334
Vested, Ending Balance			18,662
Vested and Expected to Vest, Ending Balance			174,574
Weighted Average Grant Date Fair Value
Outstanding, Beginning Balance			$ 25.80	$ 26.28
Granted			$ 26.48	$ 25.37
Converted to common stock			$ 26.18
Forfeited			$ 24.83
Outstanding, Ending Balance			$ 26.20	$ 25.80
Vested, Ending Balance			$ 26.97
Vested and Expected to Vest, Ending Balance			$ 26.21
Aggregate Intrinsic Value
Outstanding, Ending Balance			$ 6,087,000
Vested, Ending Balance			631,000
Vested and Expected to Vest, Ending Balance			5,901,000
Additional Disclosures
Total intrinsic value relating to fully vested stock-based awards converted during the period			220,000
Vesting period (in years)						5 years 3 months 19 days		3 years	5 years
Performance period (in years)							3 years
Shares Vested and Issued In Subsequent Period
Vested (in shares)					5,568
Shares converted into common stock, after reduction of shares retained to satisfy deferral requirements (in shares)					4,149
Dividend Equivalents [Abstract]
Accrued during the period	113,000									113,000
Paid during the period										4,000	0
Carrying value at period end	$ 76,927,000	$ 277,753,000								$ 116,000	$ 7,000