Projected Benefit Obligation (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Current service cost	$ 1,077	$ 1,064	$ 982
Interest cost	576	523	392
Plan participant contributions	241	192
Benefit payments	(508)	(156)
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Balance at beginning period	12,546	8,965
Current service cost	1,077	1,064
Foreign currency exchange (gain) loss	(535)	692
Interest cost	575	523
Net actuarial loss	2,147	1,266
Plan participant contributions	241	192
Benefit payments	(508)	(156)
Balance at end period	$ 15,543	$ 12,546