Stock-Based Compensation Performance Shares, RSUs, Restricted Stock and Stock Unit Awards (Details) (USD $)	12 Months Ended
	Jul. 31, 2013	Jul. 31, 2012
Performance Shares, RSUs, Restricted Stock and Stock Units [Member]
Awards (In Shares)
Outstanding, Beginning Balance	48,081	0
Granted	54,253	48,081
Converted to common stock	0	0
Forfeited	0	0
Outstanding, Ending Balance	102,334	48,081
Vested, Ending Balance	4,515
Vested and Expected to Vest, Ending Balance	98,174
Weighted Average Grant Date Fair Value
Outstanding, Beginning Balance	$ 26.28	$ 0.00
Granted	$ 25.37	$ 26.28
Converted to common stock	$ 0.00	$ 0.00
Forfeited	$ 0.00	$ 0.00
Outstanding, Ending Balance	$ 25.80	$ 26.28
Vested, Ending Balance	$ 26.71
Vested and Expected to Vest, Ending Balance	$ 25.80
Aggregate Intrinsic Value
Outstanding, Ending Balance	$ 2,771,000
Vested, Ending Balance	122,000
Vested and Expected to Vest, Ending Balance	$ 2,659,000
Shares Vested and Issued In Subsequent Period
Granted	54,253	48,081
Performance Shares [Member] | Subsequent Event [Member]
Awards (In Shares)
Granted		35,003
Shares Vested and Issued In Subsequent Period
Date that the Board of Directors determined the pre-established performance goal has been met	Oct. 02, 2013
Granted		35,003
Vested	6,996
Shares converted into common stock, net of minimum tax withholding and deferral requirements	3,496
Performance Shares [Member] | Employees [Member]
Additional Disclosures
Vesting period (in years)	5 years 3 months 19 days
RSUs and restricted stock [Member] | Non-Employee Director [Member]
Additional Disclosures
Vesting period (in years)	3 years
RSUs and restricted stock [Member] | Employees [Member]
Additional Disclosures
Vesting period (in years)	5 years