OPERATING SEGMENTS Financial Information by Geographic Region (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2011	Apr. 30, 2011	Jan. 31, 2011	Oct. 31, 2010	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2010
Financial Information by Geographic Region
Sales to unaffiliated customers	$ 61,116	$ 59,780	$ 60,203	$ 59,582	$ 57,731	$ 55,538	$ 57,201	$ 56,285	$ 240,681	$ 226,755	$ 219,050
Income (Loss) Before Income Taxes									8,361	12,141	12,814
Net Income (Loss)	(108)	1,892	3,239	1,075	2,895	1,860	1,777	2,519	6,098	9,051	9,458
Identifiable Assets	174,267				173,393				174,267	173,393	153,982
Domestic
Financial Information by Geographic Region
Sales to unaffiliated customers									229,382	214,239	205,322
Sales or transfers between geographic areas									4,440	4,949	4,830
Income (Loss) Before Income Taxes									9,382	12,815	13,318
Net Income (Loss)									6,974	9,618	9,977
Identifiable Assets	165,565				163,696				165,565	163,696	144,558
Foreign Subsidiaries
Financial Information by Geographic Region
Sales to unaffiliated customers									11,299	12,516	13,728
Income (Loss) Before Income Taxes									(1,021)	(674)	(504)
Net Income (Loss)									(876)	(567)	(519)
Identifiable Assets	$ 8,702				$ 9,697				$ 8,702	$ 9,697	$ 9,424