Assets and Liabilities Carried at Fair Value Measured on Recurring Basis (Detail) (Fair Value, Measurements, Recurring, USD $) In Thousands, unless otherwise specified	Oct. 31, 2012		Jul. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 14,617		$ 14,590
Foreign currency forward contracts	12		72
Total assets	14,629		14,662
Foreign currency forward contracts	16		6
Contingent consideration	435	[1]	460	[1]
Total liabilities	451		466
Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency forward contracts	12		72
Total assets	12		72
Foreign currency forward contracts	16		6
Total liabilities	16		6
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	14,617		14,590
Total assets	14,617		14,590
Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	435	[1]	460	[1]
Total liabilities	$ 435		$ 460

[1] The amount of contingent consideration relates to the acquisition to acquire certain assets of an OEM ultrasound transducer and probe business in November 2010. We estimated the contingent consideration based on probability weighted expected future cash flows discounted at a rate of approximately 22.1%. The contingent consideration is marked to market at the end of each fiscal quarter and is expected to be paid in Fiscal Year 2013.