Stock-Based Compensation Performance Shares, RSUs, Restricted Stock and Share Unit Awards (Details) - USD ($)	12 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2013
Additional Disclosures
Cash payments to remit employee's minimum statutory withholding requirements related to the net settlement of stock-based awards	$ 473,000	$ 1,151,000	$ 0
Dividend Equivalents [Abstract]
Accrued during the period	224,000	113,000
Carrying value at period end	72,468,000	76,927,000
Amount included in other liabilities	$ 3,633,000	$ 4,364,000
Performance Shares, RSUs, Restricted Stock and Share Units [Member]
Awards (In Shares)
Outstanding, Beginning Balance	180,097	102,334	48,081
Granted	66,294	95,326	54,253
Converted to common stock	(18,422)	(7,857)
Forfeited	(3,804)	(9,706)
Outstanding, Ending Balance	224,165	180,097	102,334
Vested, Ending Balance	33,796
Vested and Expected to Vest, Ending Balance	172,305
Weighted Average Grant Date Fair Value
Outstanding, Beginning Balance	$ 26.20	$ 25.80	$ 26.28
Granted	33.96	26.48	25.37
Converted to common stock	27.79	26.18
Forfeited	32.47	24.83
Outstanding, Ending Balance	28.26	$ 26.20	$ 25.80
Vested, Ending Balance	27.13
Vested and Expected to Vest, Ending Balance	$ 28.27
Aggregate Intrinsic Value
Outstanding, Ending Balance	$ 6,458,000
Vested, Ending Balance	974,000
Vested and Expected to Vest, Ending Balance	4,964,000
Additional Disclosures
Total intrinsic value relating to fully vested stock-based awards converted during the period	$ 654,000
Performance Shares [Member]
Additional Disclosures
Vested (in shares)	5,568
Shares converted into common stock, after reduction of shares retained to satisfy deferral requirements (in shares)	4,149
Performance Shares [Member] | Employees [Member] | Granted prior to fiscal 2014 [Member]
Additional Disclosures
Vesting period (in years)	5 years 3 months 19 days
Performance Shares [Member] | Employees [Member] | Granted Since Fiscal 2014 [Member]
Additional Disclosures
Performance period (in years)	3 years
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
Dividend Equivalents [Member]
Dividend Equivalents [Abstract]
Accrued during the period	$ 224,000	$ 113,000
Paid during the period	15,000	4,000	$ 0
Carrying value at period end	325,000	116,000
Amount included in other liabilities	$ 306,000	$ 106,000