DEBT (Components of Interest Expense) (Details) - 2016 Convertible Senior Notes - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Amortization of the discount on the liability component	$ 8,073	$ 7,917	$ 7,104
Cash interest related to the contractual interest coupon	3,407	3,430	3,342
Total	11,480	11,347	10,446
Amortization of debt discount, capitalized interest	300	600	900
Cash interest related to contractual interest coupon, capitalized interest	$ 100	$ 300	$ 400