Stock-Based Compensation - Stock Options (Details) - USD ($)		3 Months Ended			6 Months Ended
	Jan. 31, 2020	Jan. 31, 2020	Oct. 31, 2019	Jan. 31, 2019	Jan. 31, 2020	Jan. 31, 2019
Additional Disclosures
Net settlement of stock-based awards (in shares)					27,902	9,345
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options grants (in shares)						0
Awards (in Shares)
Outstanding, Beginning Balance (in shares)		1,503,295	1,555,555		1,555,555
Exercised (in shares)		(233,330)	(51,460)
Expired/canceled (in shares)		(100)	(800)
Outstanding, Ending Balance (in shares)	1,269,865	1,269,865	1,503,295		1,269,865
Exercisable (in shares)	1,200,435	1,200,435			1,200,435
Vested and Expected to Vest, Ending Balance (in shares)	1,251,302	1,251,302			1,251,302
Weighted Average Exercise Price
Outstanding, Beginning Balance (in dollars per share)		$ 28.73	$ 28.72		$ 28.72
Exercised (in dollars per share)		28.90	28.45
Expired/canceled (in dollars per share)		28.35	27.35
Outstanding, Ending Balance (in dollars per share)	$ 28.70	28.70	$ 28.73		28.70
Exercisable, Ending Balance (in dollars per share)	28.81	28.81			28.81
Vested and Expected to Vest, Ending Balance (in dollars per share)	$ 28.73	$ 28.73			$ 28.73
Weighted Average Remaining Contractual Term (Years)
Outstanding, Ending Balance					3 years 3 months 29 days
Exercisable, Ending Balance					3 years 2 months 11 days
Vested And Expected To Vest, Ending Balance					3 years 3 months 16 days
Aggregate Intrinsic Value
Outstanding, Ending Balance	$ 1,418,000	$ 1,418,000			$ 1,418,000
Exercisable, Ending Balance	1,281,000	1,281,000			1,281,000
Vested and Expected to Vest, Ending Balance	$ 1,384,000	1,384,000			1,384,000
Additional Disclosures
Exercise price, lower range limit (in dollars per share)	$ 20.90
Exercise price, upper range limit (in dollars per share)	$ 33.94
Total intrinsic value of stock-based awards settled		$ 1,559,000		$ 0	$ 1,864,000	$ 561,000
Vested stock based awards net settled upon exercise (in shares)		268,090				72,830
Minimum | Stock Options
Additional Disclosures
Contractual term (in years)	5 years
Vesting period (in years)	3 years
Maximum | Stock Options
Additional Disclosures
Contractual term (in years)	10 years
Vesting period (in years)	5 years