SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Supplemental Cash Flow Elements [Abstract]
Cash paid for interest (net of capitalized interest)	$ 156,654	$ 152,201	$ 115,006
Cash paid for income taxes	1,705	663	510
Capitalized interest	21,257	9,903	7,007
Non-cash financing activities:
Capital expenditures incurred but not yet paid	87,900	60,400	110,200
Class B Units
Non-cash financing activities:
Issuance of Class B Units in lieu of quarterly cash distribution	$ 0	$ 0	$ 25,687