Condensed Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury stock, at cost
Beginning Balance (in shares) at Jul. 31, 2018		41,706,084
Beginning Balance at Jul. 31, 2018	$ 608,867	$ 4,624	$ 184,212	$ 491,540	$ (11,456)	$ (60,053)
Increase (Decrease) in Stockholders' Equity
Repurchases of shares (in shares)		(37,802)
Repurchases of shares	(4,288)					(4,288)
Stock-based compensation	2,576		2,576
Equity vests/option exercises (in shares)		53,320
Equity vests/option exercises	955	$ 7	948
Cancellations of restricted stock (in shares)		(286)
Cancellations of restricted stock	0
Net income (loss)	19,242			19,242
Other	(634)		(634)
Other comprehensive income (loss)	(5,223)				(5,223)
Ending Balance (in shares) at Oct. 31, 2018		41,721,316
Ending Balance at Oct. 31, 2018	622,360	$ 4,631	187,102	511,647	(16,679)	(64,341)
Beginning Balance (in shares) at Jul. 31, 2018		41,706,084
Beginning Balance at Jul. 31, 2018	608,867	$ 4,624	184,212	491,540	(11,456)	(60,053)
Increase (Decrease) in Stockholders' Equity
Net income (loss)	46,217
Other comprehensive income (loss)	(8,199)
Ending Balance (in shares) at Apr. 30, 2019		41,765,917
Ending Balance at Apr. 30, 2019	655,865	$ 4,636	201,116	534,449	(19,655)	(64,681)
Beginning Balance (in shares) at Oct. 31, 2018		41,721,316
Beginning Balance at Oct. 31, 2018	622,360	$ 4,631	187,102	511,647	(16,679)	(64,341)
Increase (Decrease) in Stockholders' Equity
Repurchases of shares (in shares)		(880)
Repurchases of shares	(67)					(67)
Stock-based compensation	3,587		3,587
Equity vests/option exercises (in shares)		1,857
Cancellations of restricted stock (in shares)		(1,107)
Cancellations of restricted stock	0
Dividends on common stock	(4,173)			(4,173)
Net income (loss)	18,800			18,800
Other	1,513		1,513
Other comprehensive income (loss)	(417)				(417)
Ending Balance (in shares) at Jan. 31, 2019		41,721,186
Ending Balance at Jan. 31, 2019	641,603	$ 4,631	192,202	526,274	(17,096)	(64,408)
Increase (Decrease) in Stockholders' Equity
Repurchases of shares (in shares)		(3,712)
Repurchases of shares	(273)					(273)
Stock-based compensation	5,722		5,722
Issuance of shares (in shares)		42,705
Issuance of shares	3,197	$ 4	3,193
Equity vests/option exercises (in shares)		5,875
Equity vests/option exercises	0	$ 1	(1)
Cancellations of restricted stock (in shares)		(137)
Cancellations of restricted stock	0
Net income (loss)	8,175			8,175
Other comprehensive income (loss)	(2,559)				(2,559)
Ending Balance (in shares) at Apr. 30, 2019		41,765,917
Ending Balance at Apr. 30, 2019	$ 655,865	$ 4,636	201,116	534,449	(19,655)	(64,681)
Beginning Balance (in shares) at Jul. 31, 2019	41,771,228	41,771,228
Beginning Balance at Jul. 31, 2019	$ 661,537	$ 4,636	204,795	539,097	(22,197)	(64,794)
Increase (Decrease) in Stockholders' Equity
Repurchases of shares (in shares)		(49,614)
Repurchases of shares	(3,613)					(3,613)
Stock-based compensation	2,404		2,404
Issuance of shares (in shares)		751,471
Issuance of shares	60,000	$ 75	59,925
Equity vests/option exercises (in shares)		104,686
Equity vests/option exercises	919	$ 11	908
Cancellations of restricted stock (in shares)		(946)
Cancellations of restricted stock	0
Net income (loss)	5,767			5,767
Other comprehensive income (loss)	5,177				5,177
Ending Balance (in shares) at Oct. 31, 2019		42,576,825
Ending Balance at Oct. 31, 2019	$ 732,191	$ 4,722	268,032	544,864	(17,020)	(68,407)
Beginning Balance (in shares) at Jul. 31, 2019	41,771,228	41,771,228
Beginning Balance at Jul. 31, 2019	$ 661,537	$ 4,636	204,795	539,097	(22,197)	(64,794)
Increase (Decrease) in Stockholders' Equity
Equity vests/option exercises (in shares)	25,000
Net income (loss)	$ 19,291
Other comprehensive income (loss)	$ (19,895)
Ending Balance (in shares) at Apr. 30, 2020	42,145,737	42,145,737
Ending Balance at Apr. 30, 2020	$ 688,469	$ 4,679	240,625	553,917	(42,092)	(68,660)
Beginning Balance (in shares) at Oct. 31, 2019		42,576,825
Beginning Balance at Oct. 31, 2019	732,191	$ 4,722	268,032	544,864	(17,020)	(68,407)
Increase (Decrease) in Stockholders' Equity
Repurchases of shares (in shares)		(1,218)
Repurchases of shares	(87)					(87)
Stock-based compensation	3,412		3,412
Issuance of shares	(5,608)		(5,608)
Equity vests/option exercises (in shares)		3,900
Equity vests/option exercises	1		1
Cancellations of restricted stock (in shares)		(232)
Cancellations of restricted stock	0
Dividends on common stock	(4,471)			(4,471)
Net income (loss)	(2,263)			(2,263)
Other comprehensive income (loss)	106				106
Ending Balance (in shares) at Jan. 31, 2020		42,579,275
Ending Balance at Jan. 31, 2020	723,281	$ 4,722	265,837	538,130	(16,914)	(68,494)
Increase (Decrease) in Stockholders' Equity
Repurchases of shares (in shares)		(441,153)
Repurchases of shares	(28,445)	$ (44)	(28,235)			(166)
Stock-based compensation	3,027		3,027
Equity vests/option exercises (in shares)		7,615
Equity vests/option exercises	(3)	$ 1	(4)
Net income (loss)	15,787			15,787
Other comprehensive income (loss)	$ (25,178)				(25,178)
Ending Balance (in shares) at Apr. 30, 2020	42,145,737	42,145,737
Ending Balance at Apr. 30, 2020	$ 688,469	$ 4,679	$ 240,625	$ 553,917	$ (42,092)	$ (68,660)