SIGNIFICANT ACCOUNTING POLICIES (Narrative) (Details) (USD $)	3 Months Ended							9 Months Ended	12 Months Ended			1 Months Ended	12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Jun. 30, 2013	Mar. 31, 2013	Sep. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Feb. 28, 2014	Dec. 31, 2010	Sep. 30, 2012	Feb. 18, 2014	Jun. 30, 2011	Jan. 01, 2011
Significant Accounting Policies [Line Items]
Deferred income taxes, net	$ 27,453,000				$ 20,790,000				$ 27,453,000	$ 20,790,000
Accumulated deficit	(181,525,000)				(198,589,000)				(181,525,000)	(198,589,000)
Deferred tax assets	(14,681,000)				(14,614,000)				(14,681,000)	(14,614,000)
Restricted cash	400,000				0				400,000	0
Unbilled revenue within accounts receivable	5,100,000				5,700,000				5,100,000	5,700,000
Billing period lag (in days)									30 days
Provision for doubtful accounts									456,000	514,000	1,089,000
Write-offs of doubtful accounts									700,000	600,000	900,000
Accounts receivable, allowance for doubtful accounts	600,000				800,000				600,000	800,000	800,000
Capitalized Computer Software, Additions									22,000,000	17,500,000	15,300,000
Capitalized software depreciation expense									14,600,000	13,700,000	12,100,000
Asset impairments									4,978,000	1,196,000	879,000
Investment accounted for under cost method investment	1,100,000				2,100,000				1,100,000	2,100,000
USF charges									24,900,000	27,300,000	32,000,000
Net revenue	139,162,000	140,383,000	144,287,000	143,239,000	134,625,000	132,178,000	129,492,000	130,570,000	567,071,000	526,865,000	505,281,000
Shares repurchased (in shares)									1,900,000	100,000
Repurchase and retirement of common stock, value									24,595,000	1,381,000	27,892,000
Average price per share paid for stock repurchase									$ 12.93	$ 10.54
Shares withheld in satisfaction of employee tax withholding obligations									209,721	215,387
Payments related to tax withholding for share-based compensation									2,500,000	2,700,000
Preferred stock, shares authorized	5,000,000.0								5,000,000.0
Preferred stock, par or stated value per share	$ 0.01								$ 0.01
Advertising and promotion costs									12,300,000	6,100,000	8,900,000
Available-for-sale securities	327,000				3,537,000				327,000	3,537,000
Investment In Cloud Solutions Provider
Significant Accounting Policies [Line Items]
Investment accounted for under cost method investment							1,000,000
Convertible Investment In Marketplace
Significant Accounting Policies [Line Items]
Investment accounted for under cost method investment														1,000,000
Interest earned on cost method investment (as a percent)									8.00%
Investment In Conferencing Company
Significant Accounting Policies [Line Items]
Investment accounted for under cost method investment																1,000,000
Available-for-sale securities	300,000				3,500,000				300,000	3,500,000
Percent of investment sold												50.00%			50.00%
Investment accounted for under cost method investment												1,000,000
Gain on sale of investment												500,000
Minimum
Significant Accounting Policies [Line Items]
Finite lived intangible assets useful life (in years)									1 year
Maximum
Significant Accounting Policies [Line Items]
Finite lived intangible assets useful life (in years)									20 years
Furniture and fixtures | Minimum
Significant Accounting Policies [Line Items]
Tangible assets estimated useful life (in years)									5 years
Furniture and fixtures | Maximum
Significant Accounting Policies [Line Items]
Tangible assets estimated useful life (in years)									7 years
Capitalized software | Minimum
Significant Accounting Policies [Line Items]
Finite lived intangible assets useful life (in years)									2 years
Capitalized software | Maximum
Significant Accounting Policies [Line Items]
Finite lived intangible assets useful life (in years)									5 years
Computer, communication and network equipment | Minimum
Significant Accounting Policies [Line Items]
Tangible assets estimated useful life (in years)									3 years
Computer, communication and network equipment | Maximum
Significant Accounting Policies [Line Items]
Tangible assets estimated useful life (in years)									5 years
Software Development | Maximum
Significant Accounting Policies [Line Items]
Finite lived intangible assets useful life (in years)									5 years
Adjustments
Significant Accounting Policies [Line Items]
Loss from discontinued operation													12,300,000
Deferred income taxes, net					1,909,000					1,909,000			1,900,000
Accumulated deficit					(1,909,000)					(1,909,000)							(1,900,000)
Deferred tax assets																	1,900,000
Resold services revenue
Significant Accounting Policies [Line Items]
Net revenue									61,021,000	65,096,000	69,655,000
Resold services revenue | ACT
Significant Accounting Policies [Line Items]
Net revenue									$ 3,900,000	$ 1,400,000