LONG-TERM DEBT (Details) (USD $)	9 Months Ended			1 Months Ended		3 Months Ended	6 Months Ended	9 Months Ended		1 Months Ended	9 Months Ended		1 Months Ended		1 Months Ended	9 Months Ended					9 Months Ended	1 Months Ended			1 Months Ended		3 Months Ended				1 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Feb. 29, 2012 8% Note	Dec. 31, 2011 8% Note	Mar. 31, 2012 8% Note	Jun. 30, 2012 8% Note	Sep. 30, 2012 8% Note	Feb. 08, 2012 8% Note	Jul. 31, 2012 9.75% Senior Notes	Sep. 30, 2012 9.75% Senior Notes	Jul. 16, 2012 9.75% Senior Notes	Aug. 31, 2012 Amended revolving credit facility	Aug. 04, 2012 Amended revolving credit facility	Feb. 29, 2012 February 2012 Credit Facility	Sep. 30, 2012 February 2012 Credit Facility item multiple	Feb. 08, 2012 February 2012 Credit Facility	Sep. 30, 2012 February 2012 Credit Facility Minimum	Sep. 30, 2012 February 2012 Credit Facility Maximum	Aug. 04, 2012 February 2012 Credit Facility Maximum	Sep. 30, 2012 February 2012 Credit Facility Maximum First 24 months	Feb. 29, 2012 March 2011 Credit Facilities	Sep. 30, 2012 March 2011 Credit Facilities	Dec. 31, 2011 March 2011 Credit Facilities	Feb. 29, 2012 March 2011 revolving credit facility	Mar. 31, 2011 March 2011 revolving credit facility	Mar. 31, 2011 March 2011 revolving credit facility	Dec. 31, 2011 March 2011 revolving credit facility	Mar. 31, 2011 March 2011 revolving credit facility Minimum	Mar. 31, 2011 March 2011 revolving credit facility Maximum	Mar. 31, 2011 March 2011 term loan facility	Dec. 31, 2011 March 2011 term loan facility
Long-term debt
Long-term debt	$ 1,175,000,000		$ 202,000,000					$ 249,979,000			$ 740,021,000												$ 185,000,000	$ 127,000,000								$ 75,000,000
Interest rate (as a percent)				8.00%				8.00%	8.00%		9.75%	9.75%
Issue price as a percentage of par value										98.646%
Unamortized discount								39,700,000	43,600,000		10,000,000	10,200,000
Principal amount												750,000,000
Net proceeds from the offering				275,000,000						723,100,000
Principal amount of debt issued				275,000,000	275,000,000
Pay in-kind interest	14,669,000	362,000				3,200,000	5,700,000	5,800,000
Amount of principal and accrued interest that is convertible into one share of the entity's common stock (in dollars per share)								$ 4.50
Maximum borrowing capacity														1,500,000,000			500,000,000									250,000,000	250,000,000				75,000,000
Letters of credit outstanding																1,300,000
Credit facility term															5 years											5 years					5 years 6 months
Current borrowing capacity																338,700,000	225,000,000			525,000,000						150,000,000	150,000,000
Number of interim unscheduled redeterminations of borrowing base to which the company and lender each have the right																1
Number of consecutive semi-annual redeterminations between which the company and the lenders each have the right to one interim unscheduled redetermination of borrowing base																2
Multiple applied to stated principal amount of any future notes or other long-term debt securities that the company may issue to calculate reduction in borrowing base																0.25
Variable rate base																LIBOR										LIBOR					LIBOR
Applicable margin (as a percent)																		1.50%	2.50%										2.50%	3.25%	9.00%
Percentage of projected production for specified period of which commodity hedges on rolling basis are required to be maintained																					85.00%
Variable rate basis floor (as a percent)																															2.00%
Applicable margin, if a portion of interest is elected to be paid in kind (as a percent)																															10.00%
Variable rate basis floor, if a portion of interest is elected to be paid in kind (as a percent)																															2.00%
Portion of interest paid in cash (as a percent)																															7.00%
Portion of interest paid in kind (as a percent)																															3.00%
Amount outstanding																185,000,000												127,000,000				75,000,000
Interest expense related to an early termination penalty																						1,500,000
Costs associated with the issuance of debt capitalized								3,300,000			16,800,000					4,400,000
Debt issuance costs expensed															2,900,000										5,800,000		2,700,000
Unamortized debt issuance cost	$ 23,531,000		$ 5,966,000
Percentage of production for commodity hedging													85.00%
Period for which commodity hedges on rolling basis are required to be maintained													66 months