MARKETABLE SECURITIES - UNREALIZED LOSS POSITION (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) item
Marketable securities
Fair Value, Less Than 12 Months	$ 72,383
Gross Unrealized Losses, Less than 12 months	(34)
Fair Value, Total	72,383
Gross Unrealized Losses, Total	(34)
Other than temporary impairments	$ 0
Corporate debt securities
Marketable securities
Number of securities in an unrealized loss position | item	39
Fair Value, Less Than 12 Months	$ 72,383
Gross Unrealized Losses, Less than 12 months	(34)
Fair Value, Total	72,383
Gross Unrealized Losses, Total	$ (34)