FAIR VALUE MEASUREMENTS (Details) (Fair Value, Measurements, Recurring [Member], USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Assets: [Abstract]
Derivative assets	$ 28,806	$ 53,447
Noncurrent investments	11,249	11,148
Deferred Compensation Plan	3,502	3,775
Supplemental retirement benefit trust life insurance policies	8,259	7,898
Total financial assets, fair value	51,816	76,268
Liabilities: [Abstract]
Derivative liabilities	83,352	196,233
Long-term debt	1,915,475	1,846,867
Total financial liabilities, fair value	1,998,827	2,043,100
Net fair value assets/(liabilities)	(1,947,011)	(1,966,832)
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets: [Abstract]
Derivative assets	0	0
Noncurrent investments	11,249	11,148
Deferred Compensation Plan	3,502	3,775
Supplemental retirement benefit trust life insurance policies	0	0
Total financial assets, fair value	14,751	14,923
Liabilities: [Abstract]
Derivative liabilities	0	0
Long-term debt	0	0
Total financial liabilities, fair value	0	0
Net fair value assets/(liabilities)	14,751	14,923
Significant Other Observable Inputs (Level 2) [Member]
Assets: [Abstract]
Derivative assets	0	0
Noncurrent investments	0	0
Deferred Compensation Plan	0	0
Supplemental retirement benefit trust life insurance policies	8,259	7,898
Total financial assets, fair value	8,259	7,898
Liabilities: [Abstract]
Derivative liabilities	0	0
Long-term debt	1,915,475	1,846,867
Total financial liabilities, fair value	1,915,475	1,846,867
Net fair value assets/(liabilities)	(1,907,216)	(1,838,969)
Significant Unobservable Inputs (Level 3) [Member]
Assets: [Abstract]
Derivative assets	28,806	53,447
Noncurrent investments	0	0
Deferred Compensation Plan	0	0
Supplemental retirement benefit trust life insurance policies	0	0
Total financial assets, fair value	28,806	53,447
Liabilities: [Abstract]
Derivative liabilities	83,352	196,233
Long-term debt	0	0
Total financial liabilities, fair value	83,352	196,233
Net fair value assets/(liabilities)	$ (54,546)	$ (142,786)