Components of Total Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2012
Schedule of Unrecognized Tax Benefits [Line Items]
Unrecognized tax benefits	$ 13,156	$ 20,813	$ 32,733	$ 33,900
Reduction to unrecognized tax benefits for tax credit carry forward	(2,109)	(657)	(440)
Accrued interest and penalties	1,895	5,200	11,671
Total unrecognized tax benefits	12,942	25,356	43,964
Short-term, included in "Income and other taxes"	997	1,667	2,745
Long-term	11,945	23,689	41,219
Total unrecognized tax benefits	$ 12,942	$ 25,356	$ 43,964