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, 2014	$ 396,925,000	$ 3,102,000	$ 421,240,000	$ 409,443,000	$ (436,860,000)
Common stock shares issued, beginning of period (in shares) at Jul. 31, 2014		31,016,469
Treasury stock shares outstanding, beginning of period (in shares) at Jul. 31, 2014					14,857,582
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity-classified stock award compensation	1,337,000		1,337,000
Proceeds from issuance of employee stock purchase plan shares	243,000	$ 1,000	242,000
Proceeds from issuance of employee stock purchase plan shares (in shares)		7,699
Common stock issued for net settlement of stock-based awards	(89,000)	$ 4,000	(93,000)
Common stock issued for net settlement of stock-based awards (in shares)		44,661
Cash dividends declared	(4,863,000)			(4,863,000)
(Accrual of dividend equivalents) reversal of dividend equivalents, net of accrual	(56,000)			(56,000)
Net income tax shortfall from settlement of stock-based awards	(76,000)		(76,000)
Reversal of deferred tax assets associated with expired and unexercised stock-based awards	(12,000)		(12,000)
Net income	5,225,000			5,225,000
Ending balance at Oct. 31, 2014	398,634,000	$ 3,107,000	422,638,000	409,749,000	$ (436,860,000)
Common stock shares issued, end of period (in shares) at Oct. 31, 2014		31,068,829
Treasury stock shares outstanding, end of period (in shares) at Oct. 31, 2014					14,857,582
Beginning balance at Jul. 31, 2015	$ 401,409,000	$ 3,117,000	427,083,000	413,058,000	$ (441,849,000)
Common stock shares issued, beginning of period (in shares) at Jul. 31, 2015	31,165,401	31,165,401
Treasury stock shares outstanding, beginning of period (in shares) at Jul. 31, 2015	15,033,317				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	(4,844,000)			(4,844,000)
(Accrual of dividend equivalents) 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 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 shares issued, end of period (in shares) at Oct. 31, 2015	31,180,605	31,180,605
Treasury stock shares outstanding, end of period (in shares) at Oct. 31, 2015	15,033,317				15,033,317