Acquisition Date Fair Value of Consideration (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013 Simena	Nov. 18, 2011 Simena
Business Acquisition, Contingent Consideration [Line Items]
Initial cash payment			$ 10,086
Estimated fair value of contingent consideration obligation	5,087	8,213	8,000
Total consideration			$ 18,086	$ 10,100