Stock-Based Compensation - Stock Options (Details) - Stock Options - USD ($)	3 Months Ended
	Oct. 31, 2017	Oct. 31, 2016
Awards (in Shares)
Outstanding, Beginning Balance (in shares)	1,855,875
Expired/canceled (in shares)	(41,040)
Outstanding, Ending Balance (in shares)	1,814,835
Exercisable, Ending Balance (in shares)	1,368,086
Vested and Expected to Vest, Ending Balance (in shares)	1,768,467
Weighted Average Exercise Price
Outstanding, Beginning Balance (in dollars per share)	$ 28.60
Expired/canceled (in dollars per share)	28.97
Outstanding, Ending Balance (in dollars per share)	28.59
Exercisable, Ending Balance (in dollars per share)	28.62
Vested and Expected to Vest, Ending Balance (in dollars per share)	$ 28.57
Weighted Average Remaining Contractual Term (Years)
Outstanding, Ending Balance	5 years 3 months 24 days
Exercisable, Ending Balance	4 years 9 months 19 days
Vested And Expected To Vest, Ending Balance	5 years 3 months 8 days
Aggregate Intrinsic Value
Outstanding, Ending Balance	$ 6,000
Exercisable, Ending Balance	1,000
Vested and Expected to Vest, Ending Balance	$ 6,000
Additional Disclosures
Exercise price, lower range limit (in dollars per share)	$ 20.90
Exercise price, upper range limit (in dollars per share)	$ 33.94
Granted (in shares)	0	0
Exercised (in shares)	0	0
Vested stock based awards net settled upon exercise (in shares)	0	0
Minimum
Additional Disclosures
Contractual term (in years)	5 years
Vesting period (in years)	3 years
Maximum
Additional Disclosures
Contractual term (in years)	10 years
Vesting period (in years)	5 years