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The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.

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Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.

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The cash outflow to acquire asset without physical form usually arising from contractual or other legal rights, excluding goodwill.

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GOODWILL AND INTANGIBLE ASSETS - Narrative (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014 reporting_unit	Dec. 31, 2013	Mar. 31, 2014
Acquired Finite-Lived Intangible Assets [Line Items]
Number of reporting units			2us-gaap_NumberOfOperatingSegments
Goodwill	$ 200,271,000us-gaap_Goodwill		$ 200,271,000us-gaap_Goodwill		$ 203,446,000us-gaap_Goodwill
Carrying value of intangible assets	52,469,000		52,469,000		58,513,000
Payments to acquire software rights			131,000	713,000
Weighted average useful life of acquired intangible assets			10 years 1 month 6 days
Amortization expenses	821,000us-gaap_AmortizationOfIntangibleAssets	860,000us-gaap_AmortizationOfIntangibleAssets	2,539,000us-gaap_AmortizationOfIntangibleAssets	2,571,000us-gaap_AmortizationOfIntangibleAssets
Trade name
Acquired Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	18,600,000		18,600,000		18,600,000
Developed Technology, Accanto Systems
Acquired Finite-Lived Intangible Assets [Line Items]
Payments to acquire software rights					500,000
Weighted average useful life of acquired intangible assets					6 years 3 months 18 days
Developed technology
Acquired Finite-Lived Intangible Assets [Line Items]
Payments to acquire software rights					300,000
Weighted average useful life of acquired intangible assets					3 years
Acquired software and core technology \| Included as cost of product revenue
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization expenses	905,000	837,000	2,800,000	2,500,000
Other acquired intangible assets \| Included as operating expense
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization expenses	858,000	891,000	2,700,000	2,700,000
Developed and core technology
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful life of acquired intangible assets			6 years 8 months 12 days
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	197,900,000		197,900,000		201,000,000
Test Optimization
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 2,400,000		$ 2,400,000		$ 2,400,000