RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES Part 3 (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Total unrealized gain (loss) recognized in other comprehensive income (loss) on derivatives (effective portion)			$ (20,717,000)
Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Net	0	0	4,600,000	0
Gain (Loss) on Discontinuation of Interest Rate Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Tax	0	0	3,100,000	0
Total gain (loss) reclassified from accumulated other comprehensive income (loss) into net income on derivatives (effective portion)	(3,880,000)	(3,335,000)	(50,333,000)	(6,668,000)
Total unrealized gain (loss) recognized in other comprehensive income (loss) on derivatives (effective portion)	7,378,000	(3,596,000)	(81,592,000)	38,786,000
Commodity Contract [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total unrealized gain (loss) recognized in other comprehensive income (loss) on derivatives (effective portion)	17,133,000	(10,317,000)	(24,743,000)	3,060,000
Commodity cash flow hedge gain to be reclassified	1,500,000		1,500,000
Commodity cash flow hedge gain to be reclassified within 12 months	1,300,000		1,300,000
Commodity Cash Flow Hedge Gain To Be Reclassified After Next 12 Months Net	200,000		200,000
Commodity Contract [Member] | Revenues [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) reclassified from accumulated other comprehensive income (loss) into net income on derivatives (effective portion)	(355,000)	361,000	(31,961,000)	4,172,000
Interest Rate Contract [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total unrealized gain (loss) recognized in other comprehensive income (loss) on derivatives (effective portion)	(9,755,000)	6,721,000	(56,849,000)	35,726,000
Amount of accumulated other comprehensive income (loss) attributable primarily to settled interest-rate swaps.	(38,600,000)		(38,600,000)
Amount of loss to be recognized in the next 12 months	(4,800,000)		(4,800,000)
Interest Rate Contract [Member] | Interest Expense [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) reclassified from accumulated other comprehensive income (loss) into net income on derivatives (effective portion)	$ (3,525,000)	$ (3,696,000)	$ (18,372,000)	$ (10,840,000)