Income Taxes (Details) - USD ($)	12 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2013
Income Taxes
Consolidated effective tax rate (as a percent)	37.10%	36.90%	35.00%
Current
Federal	$ 24,602,000	$ 22,119,000	$ 18,122,000
State	3,920,000	3,710,000	3,010,000
International	1,165,000	735,000	351,000
Total	29,687,000	26,564,000	21,483,000
Deferred
Federal	(425,000)	(896,000)	(351,000)
State	(218,000)	(348,000)	223,000
International	(806,000)	26,000	(240,000)
Total	$ (1,449,000)	$ (1,218,000)	$ (368,000)