PRINCIPAL CLIENTS (Details) - USD ($) $ in Thousands			3 Months Ended		6 Months Ended
	Jun. 22, 2013	Jul. 02, 2011	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
T-Mobile USA, Inc.
Revenue, Major Customers [Line Items]
Revenue			$ 17,045	$ 17,033	$ 33,062	$ 35,123
Revenue concentration, percentage			23.10%	26.80%	21.80%	27.60%
Initial term of the master service agreement		5 years
Master services agreement, renewal term		1 year
Notice of termination option of the initial term		90 days
Sprint / United Management Co. [Member]
Revenue, Major Customers [Line Items]
Revenue			$ 11,257	$ 3,162	$ 22,129	$ 3,162
Revenue concentration, percentage			15.30%	5.00%	14.60%	2.50%
Initial term of the master service agreement		3 years
Master services agreement, renewal term		1 month
Notice of termination option of the initial term		30 days
AT&T Services, Inc. and AT&T Mobility, LLC
Revenue, Major Customers [Line Items]
Revenue			$ 9,734	$ 8,070	$ 20,221	$ 18,810
Revenue concentration, percentage			13.20%	12.70%	13.30%	14.80%
Comcast Cable Communications Management LLC
Revenue, Major Customers [Line Items]
Revenue			$ 7,025	$ 7,930	$ 14,241	$ 16,809
Revenue concentration, percentage			9.50%	12.50%	9.40%	13.20%
Initial term of the master service agreement	1 year
Master services agreement, renewal term	1 year
Notice of termination option of the initial term	90 days