DERIVATIVE AND HEDGING ACTIVITIES (Details) (Derivatives not designated as hedging contracts, USD $)																			1 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Commodity contracts item	Dec. 31, 2012 Commodity contracts Current assets - receivables from derivative contracts	Dec. 31, 2011 Commodity contracts Current assets - receivables from derivative contracts	Dec. 31, 2012 Commodity contracts Current liabilities - liabilities from derivative contracts	Dec. 31, 2011 Commodity contracts Current liabilities - liabilities from derivative contracts	Dec. 31, 2012 Commodity contracts Other noncurrent liabilities - liabilities from derivative contracts	Dec. 31, 2011 Commodity contracts Other noncurrent liabilities - liabilities from derivative contracts	Dec. 31, 2012 Commodity contracts Other noncurrent assets - receivables from derivative contracts	Dec. 31, 2011 Commodity contracts Other noncurrent assets - receivables from derivative contracts	Dec. 31, 2012 Commodity contracts Collars Natural gas item	Dec. 31, 2012 Commodity contracts Collars Crude oil item	Dec. 31, 2012 Commodity contracts Swaps Crude oil item	Dec. 31, 2012 Commodity contracts Basis Swap Natural gas item	Dec. 31, 2012 Commodity contracts Three-way collars Crude oil item	Dec. 31, 2011 Interest rate swaps Current liabilities - liabilities from derivative contracts	Dec. 31, 2011 Interest rate swaps Other noncurrent liabilities - liabilities from derivative contracts	Feb. 28, 2012 Senior Credit Agreement Commodity contracts	Feb. 29, 2012 Senior Credit Agreement Interest rate swaps	Apr. 30, 2011 March 2011 Credit Facilities Commodity contracts
Derivative and hedging activities
Realized loss for novation fees																			$ 400,000		$ 500,000
Realized loss from termination of interest rate derivatives																				600,000
Realized loss on unwinding of excess derivative contracts																					900,000
Number of open commodity derivative contracts			47									2	28	4	1	10
Asset derivative contracts	7,799,000	3,900,000		7,428,000	1,850,000					371,000	2,050,000
Liability derivative contracts	$ (12,890,000)	$ (4,710,000)				$ (10,429,000)	$ (1,590,000)	$ (2,461,000)	$ (2,602,000)								$ (265,000)	$ (253,000)