FAIR VALUE OF CERTAIN FINANCIAL ASSETS AND LIABILITIES - Level 3 Rollforward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Auction rate securities
Fair value of level 3 financial assets, roll forward
Balance at the beginning of the period	$ 3,910	$ 16,184
Total gains (losses) for the period: Included in earnings	250	801
Settlements	(4,160)	(13,075)
Balance at the end of the period		3,910
Put options
Fair value of level 3 financial assets, roll forward
Balance at the beginning of the period	250	1,092
Total gains (losses) for the period: Included in earnings	$ (250)	(842)
Balance at the end of the period		$ 250