Stock-Based Compensation (Performance Shares, RSUs, Restricted Stock and Share Unit Awards) (Details)		12 Months Ended
	Jul. 31, 2017 $ / shares shares	Jul. 31, 2019 USD ($) $ / shares shares	Jul. 31, 2018 USD ($) $ / shares shares	Jul. 31, 2017 USD ($) $ / shares shares
Dividend Equivalents [Abstract]
Accrued during the period | $		$ 327,000	$ 300,000	$ 273,000
Carrying value at period end | $		352,629,000	339,473,000
Income tax benefit from settlement of stock-based awards | $		$ 479,000	$ 1,193,000
Net reduction to additional paid in capital from income tax shortfalls | $				$ 670,000
Performance Shares, RSUs, Restricted Stock and Share Units
Awards (In Shares)
Outstanding, Beginning Balance (in shares) | shares		818,438	830,197	217,213
Granted (in shares) | shares		442,363	473,005	705,241
Settled (in shares) | shares		(275,619)	(354,822)	(61,462)
Forfeited (in shares) | shares		(30,506)	(129,942)	(30,795)
Outstanding, Ending Balance (in shares) | shares	830,197	954,676	818,438	830,197
Vested, Ending Balance (in shares) | shares		321,702
Vested and Expected to Vest, Ending Balance (in shares) | shares		914,082
Weighted Average Grant Date Fair Value
Outstanding, Beginning Balance (in dollars per share) | $ / shares		$ 19.78	$ 16.95	$ 28.32
Granted (in dollars per share) | $ / shares		29.76	22.45	14.31
Settled (in dollars per share) | $ / shares		26.05	17.66	26.63
Forfeited (in dollars per share) | $ / shares		25.52	17.26	17.13
Outstanding, Ending Balance (in dollars per share) | $ / shares	$ 16.95	22.40	$ 19.78	$ 16.95
Vested, Ending Balance (in dollars per share) | $ / shares		25.82
Vested and Expected to Vest, Ending Balance (in dollars per share) | $ / shares		$ 22.55
Aggregate Intrinsic Value
Outstanding, Ending Balance | $		$ 28,411,000
Vested, Ending Balance | $		9,574,000
Vested and Expected to Vest, Ending Balance | $		27,203,000
Additional Disclosures
Total intrinsic value relating to fully vested stock-based awards converted during the period | $		$ 8,772,000	$ 10,473,000	$ 1,039,000
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)		3 years
Common stock, conversion ratio (in shares)		1
Share units
Awards (In Shares)
Granted (in shares) | shares		257,608
Additional Disclosures
Common stock, conversion ratio (in shares)			1
Conversion period of vested share units	1 year
Granted units converted into common stock (in shares) | shares		146,410
Number of shares issued as result of conversion | shares		90,928
Number of units settled to date (in shares) | shares		421,966
Dividend Equivalents
Dividend Equivalents [Abstract]
Accrued during the period | $		$ 327,000	$ 300,000	273,000
Paid during the period | $		263,000	141,000	$ 176,000
Carrying value at period end | $		$ 777,000	$ 713,000