Components of Net Periodic Pension Cost (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 521	$ 644	$ 368
Interest costs	743	728	589
Expected return on plan assets	(577)	(538)	(473)
Amortization of net actuarial (gain) loss	62	38	(88)
Curtailment gain		(504)
Net periodic pension costs	$ 749	$ 368	$ 396