Stock-Based Compensation - Stock Options (Details) - Stock Options - USD ($)		3 Months Ended			6 Months Ended		18 Months Ended
	Jan. 31, 2019	Jan. 31, 2019	Oct. 31, 2018	Jan. 31, 2018	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2019
Awards (in Shares)
Outstanding, Beginning Balance (in shares)		1,590,045	1,668,975		1,668,975
Exercised (in shares)			(78,930)
Expired/canceled (in shares)		(7,850)
Outstanding, Ending Balance (in shares)	1,582,195	1,582,195	1,590,045		1,582,195		1,582,195
Exercisable (in shares)	1,385,023	1,385,023			1,385,023		1,385,023
Vested and Expected to Vest, Ending Balance (in shares)	1,550,570	1,550,570			1,550,570		1,550,570
Weighted Average Exercise Price
Outstanding, Beginning Balance (in dollars per share)		$ 28.74	$ 28.72		$ 28.72
Exercised (in dollars per share)			28.37
Expired/canceled (in dollars per share)		29.30
Outstanding, Ending Balance (in dollars per share)	$ 28.74	28.74	$ 28.74		28.74		$ 28.74
Exercisable, Ending Balance (in dollars per share)	28.73	28.73			28.73		28.73
Vested and Expected to Vest, Ending Balance (in dollars per share)	$ 28.73	$ 28.73			$ 28.73		$ 28.73
Weighted Average Remaining Contractual Term (Years)
Outstanding, Ending Balance					4 years 5 days
Exercisable, Ending Balance					3 years 8 months 10 days
Vested And Expected To Vest, Ending Balance					3 years 11 months 19 days
Aggregate Intrinsic Value
Outstanding, Ending Balance	$ 91,000	$ 91,000			$ 91,000		$ 91,000
Exercisable, Ending Balance	33,000	33,000			33,000		33,000
Vested and Expected to Vest, Ending Balance	$ 79,000	79,000			79,000		$ 79,000
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		$ 0		$ 0	$ 561,000	$ 0
Granted (in shares)						0	0
Vested stock options net settled upon exercise (in shares)					72,830
Net settlement of stock-based awards (in shares)					9,345
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