CASH, CASH EQUIVALENTS AND SHORT TERM INVESTMENTS (Schedule of Cash, Cash Equivalents and Short Term Investments) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Cash And Cash Equivalents [Line Items]
Cost	$ 15,526	$ 29,241
Gross Unrealized Gains	24	56
Gross Unrealized Losses	(42)	(50)
Estimated fair value	15,508	29,247
Government and agency securities [Member]
Cash And Cash Equivalents [Line Items]
Cost	6,233	9,912
Gross Unrealized Gains	14	31
Gross Unrealized Losses	(30)	(8)
Estimated fair value	6,217	9,935
Corporate debt securities [Member]
Cash And Cash Equivalents [Line Items]
Cost	3,102	6,709
Gross Unrealized Gains	10	25
Gross Unrealized Losses	(12)	(42)
Estimated fair value	3,100	6,692
Cash [Member]
Cash And Cash Equivalents [Line Items]
Cost	5,890	12,471
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated fair value	5,890	12,471
Money market funds [Member]
Cash And Cash Equivalents [Line Items]
Cost	301	149
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated fair value	$ 301	$ 149