FAIR VALUE MEASUREMENTS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 1 [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 1 [Member]	Sep. 30, 2014 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member]	Sep. 30, 2014 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 3 [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 3 [Member]	Sep. 30, 2014 Reported Value Measurement [Member]	Dec. 31, 2013 Reported Value Measurement [Member]	Sep. 30, 2014 Convertible notes [Member]	Jun. 30, 2014 Convertible notes [Member]	Dec. 31, 2013 Convertible notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure			$ 22,887	$ 7,600	$ 0	$ 0	$ 0	$ 0	$ 22,887	$ 7,600
Short Term Investments Fair Value Disclosure			230,968	202,024	0	0	0	0	230,968	202,024
Long Term Investments Fair Value Disclosure			2,606	3,117	0	0	0	4,300	2,606	7,417
Rollforward of changes in fair value of investments in convertible notes
Fair value of notes, beginning of period											0	0	4,300
Repayment of notes	0	(4,300)
Fair value of notes, end of period											$ 0	$ 0	$ 4,300