Accumulated Other Comprehensive Income (Loss) (Details) (USD $)	3 Months Ended
	Oct. 31, 2013	Oct. 31, 2012
Components and changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	$ 10,977,000	$ 8,175,000
Other comprehensive income (loss) before reclassifications	(306,000)	104,000
Income tax effect on other comprehensive income (loss) before reclassifications	12,000	(24,000)
Reclassification adjustments to interest expense for losses on interest rate swaps included in net income during the period	48,000	55,000
Income tax effect on reclassification adjustments	(18,000)	(21,000)
Balance at the end of the period	10,713,000	8,289,000
Foreign Currency Translation Adjustments
Components and changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	11,080,000	8,385,000
Other comprehensive income (loss) before reclassifications	(273,000)	122,000
Income tax effect on other comprehensive income (loss) before reclassifications		(31,000)
Balance at the end of the period	10,807,000	8,476,000
Interest Rate Swap Agreements
Components and changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	(103,000)	(210,000)
Other comprehensive income (loss) before reclassifications	(33,000)	(18,000)
Income tax effect on other comprehensive income (loss) before reclassifications	12,000	7,000
Reclassification adjustments to interest expense for losses on interest rate swaps included in net income during the period	48,000	55,000
Income tax effect on reclassification adjustments	(18,000)	(21,000)
Balance at the end of the period	$ (94,000)	$ (187,000)