MARKETABLE SECURITIES (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Current available-for-sale marketable securities
Amortized Cost	$ 34,278	$ 1,220
Gross Unrealized Gains	5,283	4,784
Gross Unrealized Losses	(18)	0
Marketable securities	39,543	6,004
Contractual maturities of debt securities classified as available-for-sale
Due in one year or less, amortized cost	6,081
Due after one year through five years, amortized cost	27,883
Total Amortized Cost	33,964
Due in one year or less, fair value	6,082
Due after one year through five years, fair value	27,879
Total, Estimated Fair Value	33,961
Total debt securities
Current available-for-sale marketable securities
Amortized Cost	33,964	1,004
Gross Unrealized Gains	15	4
Gross Unrealized Losses	(18)	0
Marketable securities	33,961	1,008
Corporate debt securities
Current available-for-sale marketable securities
Amortized Cost	33,964	1,004
Gross Unrealized Gains	15	4
Gross Unrealized Losses	(18)	0
Marketable securities	33,961	1,008
Equity securities
Current available-for-sale marketable securities
Amortized Cost	314	216
Gross Unrealized Gains	5,268	4,780
Gross Unrealized Losses	0	0
Marketable securities	$ 5,582	$ 4,996