DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS - Location of Assets and Liabilities Within the Consolidated Balance Sheets (Details) - Not Designated as Hedging Instruments - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 25,207	$ 111,319
Liability Derivatives	256,135	132,978
Interest Rate Swap | Current derivative contracts
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	1,975
Interest Rate Swap | Short-term liabilities under derivative contracts
Derivatives, Fair Value [Line Items]
Liability Derivatives	469	70
Interest Rate Swap | Long-term liabilities under derivative contracts
Derivatives, Fair Value [Line Items]
Liability Derivatives	(160,871)	(132,908)
Prepaid forward contracts | Long-term derivative contracts
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	25,207	109,344
Prepaid forward contracts | Short-term liabilities under derivative contracts
Derivatives, Fair Value [Line Items]
Liability Derivatives	0	0
Prepaid forward contracts | Long-term liabilities under derivative contracts
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ (94,795)	$ 0