SEGMENT REPORTING (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Net revenue:	$ 144,304	$ 144,287	$ 286,626	$ 287,526
Operating income (loss):	8,101	10,852	12,909	21,219
Conferencing services revenue
Segment Reporting Information [Line Items]
Net revenue:	111,340	116,935	221,880	233,323
UC&C SaaS revenue
Segment Reporting Information [Line Items]
Net revenue:	20,469	11,996	39,215	22,729
Resold services revenue
Segment Reporting Information [Line Items]
Net revenue:	12,495	15,356	25,531	31,474
North America
Segment Reporting Information [Line Items]
Net revenue:	91,651	89,392	182,396	179,522
Operating income (loss):	(542)	1,078	(2,057)	2,950
Europe
Segment Reporting Information [Line Items]
Net revenue:	37,299	38,289	74,559	75,417
Operating income (loss):	7,712	9,065	16,000	17,098
Asia Pacific
Segment Reporting Information [Line Items]
Net revenue:	15,354	16,606	29,671	32,587
Operating income (loss):	$ 931	$ 709	$ (1,034)	$ 1,171