Fair Value Of Acquired Identifiable Intangible Assets And Related Estimates Useful Lives (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Dec. 31, 2012
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible Assets, useful life	10 years 1 month 6 days
Onpath
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible Assets	10,970
Intangible Assets, useful life	7 years 6 months
Onpath | Developed Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible Assets	4,970
Intangible Assets, useful life	8 years
Onpath | Distributor Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible Assets	6,000
Intangible Assets, useful life	7 years
Accanto Systems Srl
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible Assets	5,280
Intangible Assets, useful life	7 years 3 months 18 days
Accanto Systems Srl | Developed Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible Assets	3,500
Intangible Assets, useful life	8 years
Accanto Systems Srl | Distributor Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible Assets	1,780
Intangible Assets, useful life	6 years