Condensed Consolidated Statements of Stockholders' Equity - USD ($)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]
Beginning balance at Jul. 31, 2015	$ 401,409,000	$ 3,117,000	$ 427,083,000	$ 413,058,000	$ (441,849,000)
Common stock, beginning balance (in shares) at Jul. 31, 2015		31,165,401
Treasury stock, beginning balance (in shares) at Jul. 31, 2015					15,033,317
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity-classified stock award compensation	1,051,000		1,051,000
Proceeds from issuance of employee stock purchase plan shares	175,000	$ 1,000	174,000
Proceeds from issuance of employee stock purchase plan shares (in shares)		10,004
Common stock issued for net settlement of stock-based awards	(74,000)	$ 0	(74,000)
Common stock issued for net settlement of stock-based awards (in shares)		5,200
Cash dividends declared, net	(4,844,000)			(4,844,000)
Reversal of dividend equivalents, net of accrual	10,000			10,000
Net income tax shortfall from settlement of stock-based awards	(35,000)		(35,000)
Reversal of deferred tax assets associated with expired and unexercised stock-based awards	(21,000)		(21,000)
Net (loss) income	1,439,000			1,439,000
Ending balance at Oct. 31, 2015	399,110,000	$ 3,118,000	428,178,000	409,663,000	$ (441,849,000)
Common stock, ending balance (in shares) at Oct. 31, 2015		31,180,605
Treasury stock, ending balance (in shares) at Oct. 31, 2015					15,033,317
Beginning balance at Jul. 31, 2016	$ 470,401,000	$ 3,837,000	524,797,000	383,616,000	$ (441,849,000)
Common stock, beginning balance (in shares) at Jul. 31, 2016	38,367,997	38,367,997
Treasury stock, beginning balance (in shares) at Jul. 31, 2016	15,033,317				15,033,317
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity-classified stock award compensation	$ 970,000		970,000
Proceeds from issuance of employee stock purchase plan shares	183,000	$ 2,000	181,000
Proceeds from issuance of employee stock purchase plan shares (in shares)		16,812
Issuance of restricted stock	0	$ 14,000	(14,000)
Issuance of restricted stock (in shares)		144,899
Common stock issued for net settlement of stock-based awards	(163,000)	$ 3,000	(166,000)
Common stock issued for net settlement of stock-based awards (in shares)		25,697
Cash dividends declared, net	(7,008,000)			(7,008,000)
Accrual of dividend equivalents, net of reversal	(129,000)			(129,000)
Net income tax shortfall from settlement of stock-based awards	(161,000)		(161,000)
Reversal of deferred tax assets associated with expired and unexercised stock-based awards	(316,000)		(316,000)
Net (loss) income	(2,489,000)			(2,489,000)
Ending balance at Oct. 31, 2016	$ 461,288,000	$ 3,856,000	$ 525,291,000	$ 373,990,000	$ (441,849,000)
Common stock, ending balance (in shares) at Oct. 31, 2016	38,555,405	38,555,405
Treasury stock, ending balance (in shares) at Oct. 31, 2016	15,033,317				15,033,317