DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS, Location of Assets and Liabilities with the Consolidated Balance Sheets (Details) (Derivatives Not Designated as Hedging Instruments, USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Derivative Instruments, Fair Value [Abstract]
Asset Derivatives	$ 7,317	$ 3,385
Liability Derivatives	102,217	146,947
Prepaid forward contracts | Current derivative contracts
Derivative Instruments, Fair Value [Abstract]
Asset Derivatives	0	0
Liability Derivatives	93,010	99,577
Prepaid forward contracts | Long-term derivative contracts
Derivative Instruments, Fair Value [Abstract]
Asset Derivatives	7,317	3,385
Liability Derivatives	$ 9,207	$ 47,370