GOODWILL AND INTANGIBLE ASSETS - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Mar. 31, 2013
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 202,863,000		$ 202,863,000		$ 202,453,000
Carrying value of intangible assets	60,896,000		60,896,000		63,827,000
Amortization expenses	857,000	645,000	1,711,000	1,231,000
Weighted average useful life of acquired intangible assets			10 years 1 month 6 days
Trade name
Acquired Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	18,600,000		18,600,000		18,600,000
Acquired software and core technology
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful life of acquired intangible assets			6 years 8 months 12 days
Acquired software and core technology | Included as cost of product revenue
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization expenses	824,000	1,500,000	1,600,000	2,900,000
Other acquired intangible assets | Included as operating expense
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization expenses	884,000	674,000	1,800,000	1,300,000
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful life of acquired intangible assets			13 years 3 months 18 days
Unified Service Delivery
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	200,500,000		200,500,000		199,500,000
Test Automation
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 2,400,000		$ 2,400,000		$ 3,000,000