LONG-TERM LIABILITIES (Details) (USD $)	0 Months Ended	3 Months Ended
	Dec. 15, 2011	Mar. 31, 2013	Dec. 31, 2012
LONG-TERM LIABILITIES
Line of Credit		$ 89,500,000	$ 99,500,000
Convertible debentures		1,636,000	1,636,000
Asset retirement obligations		25,065,000	25,236,000
Litigation allowance		3,100,000	3,100,000
Total long-term liabilities		119,301,000	129,472,000
Less current portion		1,790,000	1,790,000
Long-term portion		117,511,000	127,682,000
Long-term liabilities
Number of wholly-owned subsidiaries that guarantee Line of Credit Facility		2
Number of additional redetermination rights in each year		1
Amount of bond redemptions		0
Line of Credit
Long-term liabilities
Term of credit facility	5 years
Option one per the terms of the debt agreement used in the calculation of the maximum borrowing capacity	300,000,000
Initial borrowing base			140,000,000
Credit line interest accrued, approximate		100,000
Borrowing base increased		89,500,000
Weighted average interest rate (as a percent)		2.46%
Line of Credit | Base Rate
Long-term liabilities
Variable rate basis		Base Rate
Line of Credit | Prime rate
Long-term liabilities
Variable rate basis		Prime rate
Line of Credit | Federal Funds rate
Long-term liabilities
Variable rate basis		Federal Funds
Line of Credit | LIBOR
Long-term liabilities
Variable rate basis		LIBOR
Line of Credit | Minimum
Long-term liabilities
Current ratio		1.0
Annualized consolidated EBITDAX to net interest expense ratio		2.5
Line of Credit | Minimum | LIBOR
Long-term liabilities
Margin (as a percent)		1.75%
Additional margin (as a percent)		0.75%
Line of Credit | Maximum | LIBOR
Long-term liabilities
Margin (as a percent)		2.75%
Additional margin (as a percent)		1.75%
Prior line of credit facility
Long-term liabilities
Maximum borrowing capacity under prior agreement	$ 250,000,000
Convertible debentures
Long-term liabilities
Percentage of principal amount at which debentures may be converted from the date of issuance until maturity into common stock		100.00%
Conversion price (in dollars per share)		$ 50