ACQUISITIONS - Fair Value Of Acquired Identifiable Intangible Assets and Related Estimated Useful Lives (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended	0 Months Ended
	Sep. 30, 2013	Oct. 31, 2012 Onpath	Oct. 31, 2012 Onpath Developed technology	Oct. 31, 2012 Onpath Distributor relationships	Jul. 20, 2012 Accanto Systems Srl	Jul. 20, 2012 Accanto Systems Srl Developed technology	Jul. 20, 2012 Accanto Systems Srl Distributor relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value of finite-lived intangible assets acquired		$ 10,970	$ 4,970	$ 6,000	$ 5,280	$ 3,500	$ 1,780
Estimated useful life of identifiable finite-lived intangible assets acquired	10 years 1 month 6 days	7 years 6 months	8 years	7 years	7 years 3 months 18 days	8 years	6 years