Schedule of Change in Retained Earnings (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2014	Apr. 30, 2013
Retained Earnings Adjustments [Line Items]
Beginning Balance			$ 953,740
Net income	55,122	43,757	112,422	94,641
Dividends paid			(90,057)
Ending Balance	$ 976,105		$ 976,105