Stock-Based Compensation (Performance Shares, RSUs, Restricted Stock and Share Unit Awards) (Details)		3 Months Ended		12 Months Ended
	Jul. 31, 2017	Oct. 31, 2020 USD ($) $ / shares shares	Oct. 31, 2019 USD ($)	Jul. 31, 2018	Jul. 31, 2020 USD ($)	Jul. 31, 2019
Dividend Equivalents [Abstract]
Accrued during the period		$ 142,000	$ 56,000
Carrying value at period end		458,359,000			$ 380,348,000
Income tax (expense) benefit from settlement of stock-based awards		$ (199,000)	612,000
Performance Shares, RSUs, Restricted Stock and Share Units
Awards (In Shares)
Outstanding, Beginning Balance (in shares) | shares		999,574
Granted (in shares) | shares		383,337
Settled (in shares) | shares		(176,051)
Forfeited (in shares) | shares		(65,215)
Outstanding, Ending Balance (in shares) | shares		1,141,645
Vested, Ending Balance (in shares) | shares		396,254
Vested and Expected to Vest, Ending Balance (in shares) | shares		1,098,098
Weighted Average Grant Date Fair Value
Outstanding, Beginning Balance (in dollars per share) | $ / shares		$ 21.15
Granted (in dollars per share) | $ / shares		16.67
Settled (in dollars per share) | $ / shares		20.47
Forfeited (in dollars per share) | $ / shares		16.16
Outstanding, Ending Balance (in dollars per share) | $ / shares		20.03
Vested, Ending Balance (in dollars per share) | $ / shares		16.61
Vested and Expected to Vest, Ending Balance (in dollars per share) | $ / shares		$ 20.00
Aggregate Intrinsic Value
Outstanding, Ending Balance		$ 16,439,684
Vested, Ending Balance		5,706,054
Vested and Expected to Vest, Ending Balance		15,812,607
Additional Disclosures
Total intrinsic value relating to fully vested stock-based awards converted during the period		$ 2,896,000	5,806,000
Performance shares | Employees | Granted since fiscal 2014
Additional Disclosures
Performance period (in years)		3 years
RSUs and restricted stock | Employees
Additional Disclosures
Vesting period (in years)		5 years
Common stock, conversion ratio (in shares)		1
RSUs and restricted stock | Non-Employee Director
Additional Disclosures
Vesting period (in years)		5 years		3 years
Common stock, conversion ratio (in shares)						1
Share units
Additional Disclosures
Common stock, conversion ratio (in shares)	1
Conversion period of vested share units	1 year
Number of units settled to date (in shares) | shares		672,085
Dividend equivalents
Dividend Equivalents [Abstract]
Accrued during the period		$ 142,000	56,000
Paid during the period		275,000	$ 285,000
Carrying value at period end		$ 650,000			$ 783,000