FAIR VALUE MEASUREMENTS - FAIR VALUE OF LONG TERM DEBT (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Current portion of long-term debt	$ 243	$ 499,923
Long-term portion	2,347,455	1,557,091
Long-term Debt	2,347,698	2,057,014
Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Current Maturities, Fair Value	243	509,580
Current portion of long-term debt	243	499,923
Long-term Debt, Excluding Current Maturities, Fair Value	2,379,054	1,668,379
Long-term portion	2,347,455	1,557,091
Long-term Debt, Fair Value	2,379,297	2,177,959
Long-term Debt	$ 2,347,698	$ 2,057,014