Accumulated Other Comprehensive Income (Loss) (Details) (USD $)	3 Months Ended		9 Months Ended
	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2013	Apr. 30, 2012
Components and changes in accumulated other comprehensive income (loss)
Beginning balance	$ 8,395,000	$ 8,322,000	$ 8,175,000	$ 9,283,000
Other comprehensive income (loss) before reclassifications	(303,000)	210,000	(106,000)	(988,000)
Income tax effect on other comprehensive income (loss)	73,000	(7,000)	22,000	230,000
Reclassification adjustments to interest expense for losses on interest rate swaps included in net income during the periods	53,000		168,000
Income tax effect on reclassification adjustments	(22,000)		(63,000)
Ending balance	8,196,000	8,525,000	8,196,000	8,525,000
Foreign Currency Translation Adjustments
Components and changes in accumulated other comprehensive income (loss)
Beginning balance	8,540,000	8,322,000	8,385,000	9,283,000
Other comprehensive income (loss) before reclassifications	(243,000)	371,000	(32,000)	(827,000)
Income tax effect on other comprehensive income (loss)	51,000	(67,000)	(5,000)	170,000
Ending balance	8,348,000	8,626,000	8,348,000	8,626,000
Interest Rate Swap Agreements
Components and changes in accumulated other comprehensive income (loss)
Beginning balance	(145,000)		(210,000)
Other comprehensive income (loss) before reclassifications	(60,000)	(161,000)	(74,000)	(161,000)
Income tax effect on other comprehensive income (loss)	22,000	60,000	27,000	60,000
Reclassification adjustments to interest expense for losses on interest rate swaps included in net income during the periods	53,000		168,000
Income tax effect on reclassification adjustments	(22,000)		(63,000)
Ending balance	$ (152,000)	$ (101,000)	$ (152,000)	$ (101,000)