Components of Net Deferred Tax Assets (Detail) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2012	Jul. 31, 2011
Schedule of Deferred Tax Assets and Liabilities [Line Items]
Depreciation related	$ (5,299)	$ (4,523)
Goodwill and intangibles	1,110	2,168
Compensation	14,233	9,863
Accruals and reserves	4,987	4,149
Comprehensive income	1,219	2,849
Net operating loss and credit carryforwards	7,140	6,730
Other	1,705	538
Deferred Tax Assets, Gross	25,095	21,774
Valuation allowance	(5,537)	(5,167)
Total deferred taxes	$ 19,558	$ 16,607