ACQUISITIONS (Narrative) (Details) (USD $)	3 Months Ended		0 Months Ended	12 Months Ended	0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Oct. 16, 2014	Dec. 31, 2014	Sep. 19, 2014	Feb. 05, 2015
Business Acquisition [Line Items]
Acquisition-related costs	$ 573,000	$ 1,905,000
Central Desktop
Business Acquisition [Line Items]
Acquisition-related costs				400,000
Contingent consideration liability			2,900,000
Negotiated sales price			25,000,000
Central Desktop | Developed technology
Business Acquisition [Line Items]
Finite-lived intangible assets, preliminary valuation			6,000,000
Amortization period (in years)			7 years
Central Desktop | Customer Relationships
Business Acquisition [Line Items]
Finite-lived intangible assets, preliminary valuation			1,100,000
Amortization period (in years)			10 years
Central Desktop | Non-compete agreements
Business Acquisition [Line Items]
Finite-lived intangible assets, preliminary valuation			1,800,000
Amortization period (in years)			5 years
Central Desktop | Trade Names
Business Acquisition [Line Items]
Finite-lived intangible assets, preliminary valuation			300,000
Amortization period (in years)			2 years
TalkPoint
Business Acquisition [Line Items]
Acquisition-related costs				400,000
Contingent consideration liability					6,400,000
Indemnification asset					1,100,000
Uncertain tax position					1,100,000
Negotiated sales price					56,500,000
TalkPoint | Developed technology
Business Acquisition [Line Items]
Finite-lived intangible assets, preliminary valuation					16,000,000
Amortization period (in years)					7 years
TalkPoint | Customer Relationships
Business Acquisition [Line Items]
Finite-lived intangible assets, preliminary valuation					9,500,000
Amortization period (in years)					10 years
TalkPoint | Non-compete agreements
Business Acquisition [Line Items]
Finite-lived intangible assets, preliminary valuation					2,200,000
Amortization period (in years)					5 years
TalkPoint | Trade Names
Business Acquisition [Line Items]
Finite-lived intangible assets, preliminary valuation					700,000
Amortization period (in years)					2 years
Modality
Business Acquisition [Line Items]
Acquisition-related costs	300,000
Contingent consideration liability						23,100,000
Negotiated sales price						17,500,000
Modality | Customer Relationships
Business Acquisition [Line Items]
Finite-lived intangible assets, preliminary valuation						3,600,000
Modality | Other intangibles
Business Acquisition [Line Items]
Finite-lived intangible assets, preliminary valuation						$ 2,800,000