SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Schedule of Cash, Cash Equivalents, and Short Term Investments) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Cash And Cash Equivalents [Line Items]
Cost	$ 36,536	$ 29,241
Gross unrealized gains	66	56
Gross unrealized losses	(26)	(50)
Estimated fair value	36,576	29,247
Corporate debt securities [Member]
Cash And Cash Equivalents [Line Items]
Cost	4,685	6,709
Gross unrealized gains	24	25
Gross unrealized losses	(26)	(42)
Estimated fair value	4,683	6,692
Government and agency securities [Member]
Cash And Cash Equivalents [Line Items]
Cost	6,970	9,912
Gross unrealized gains	42	31
Gross unrealized losses	0	(8)
Estimated fair value	7,012	9,935
Cash [Member]
Cash And Cash Equivalents [Line Items]
Cost	24,640	12,471
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Estimated fair value	24,640	12,471
Money market account [Member]
Cash And Cash Equivalents [Line Items]
Cost	241	149
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Estimated fair value	$ 241	$ 149