FINANCIAL MEASUREMENTS AND FINANCIAL INSTRUMENTS - CARRYING VALUE AND FAIR VALUE OF FINANCIAL INSTRUMENTS (Details 3) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current maturities of long-term debt | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term debt, fair value	$ (40,000)	$ 0
Current maturities of long-term debt | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term debt, fair value	(39,850)	0
Long-term debt, net of current maturities | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term debt, fair value	(1,748,213)	(1,080,000)
Long-term debt, net of current maturities | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term debt, fair value	$ (1,761,601)	$ (1,099,813)