INVESTMENTS - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Investment [Line Items]
Realized gain on investment	$ 0	$ 385
Available-for-sale debt security contractual maturity minimum years	10 years
Auction-rate securities
Investment [Line Items]
Adjusted Cost	$ 1,000