Assets and Liabilities Carried at Fair Value Measured on Recurring Basis (Parenthetical) (Detail) (Acquired Certain Assets of an OEM Ultrasound Transducer and Probe Business, USD $) In Thousands, unless otherwise specified	Jan. 31, 2013
Acquired Certain Assets of an OEM Ultrasound Transducer and Probe Business
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent Consideration Paid	$ 435