Summary of Significant Accounting Policies (Details Textual) (USD $)	2 Months Ended	3 Months Ended		9 Months Ended									2 Months Ended								9 Months Ended
	Nov. 30, 2012 MMBTU	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Jan. 01, 2007	Oct. 03, 2012 Additional Senior Notes Due 2022 [Member]	Sep. 30, 2012 Senior Notes Due Two Thousand Seven Teen [Member]	Sep. 30, 2012 Senior Notes Due Two Thousand Twenty [Member]	Sep. 30, 2012 Senior Notes Due 2022 [Member]	Sep. 30, 2012 Line of Credit [Member]	Nov. 30, 2012 Maximum [Member]	Nov. 30, 2012 Minimum [Member]	Sep. 30, 2012 Trade Accounts Receivable [Member]	Dec. 31, 2011 Trade Accounts Receivable [Member]	Sep. 30, 2012 Joint Interest Owners [Member]	Dec. 31, 2011 Joint Interest Owners [Member]	Sep. 30, 2012 Other Accounts Receivable [Member]	Dec. 31, 2011 Other Accounts Receivable [Member]	Sep. 30, 2012 Maximum [Member]	Sep. 30, 2012 Minimum [Member]	Dec. 31, 2011 Oil Floors [Member]
Accounts Receivable (Textual) [Abstract]
Allowance for doubtful accounts receivable, current		$ 100,000		$ 100,000		$ 100,000
Trade Accounts Receivable, Gross															39,500,000	54,700,000
Accounts receivable related to joint interest owners																	3,500,000	4,200,000
Other Receivables																			7,000,000	5,600,000
Summary of Significant Accounting Policies (Textual) [Abstract]
Total capitalized internal costs				23,900,000	21,900,000
Total capitalized interest cost on unproved properties		2,000,000	2,000,000	6,000,000	5,700,000
Property, Plant and Equipment, Useful Life																					20 years	2 years
Discount rate for estimated future net revenues from proved properties		10.00%
Net gain (loss) related to derivative activities, recognized		200,000	300,000	2,500,000	(800,000)
Other Comprehensive Income (Loss), Net of Tax		(113,000)		(113,000)		0
Fair value of derivative instruments																							100,000
Production from Price Floors	1,660,000
Price Floor Strike Price													2.97	2.92
Percentage of working interest in wells				100.00%
Total amount of supervision fees charged to wells				8,600,000	10,000,000
Inventories carried at cost		2,700,000		2,700,000		3,600,000
Inventory Write-down				100,000	1,600,000
Decrease in retained earnings for uncertain tax positions							1,000,000
Outstanding checks included in trade accounts payable		28,300,000		28,300,000		18,700,000
Maturity time period for cash and cash equivalents				3 months
Restricted cash and cash equivalents included in other long term assets		1,000,000		1,000,000		1,300,000
Asset Retirement Obligation - current portion		6,088,000		6,088,000		9,279,000
Debt Issuance Costs (Textual) [Abstract]
Senior notes, issued								150,000,000	250,000,000	225,000,000	250,000,000
Stated Rate of Senior notes								7.875%	7.125%	8.875%	7.875%
Balance of issuance costs for credit facility									2,300,000	4,100,000	4,500,000	2,900,000
Net accumulated amortization of debt issuance cost									$ 1,900,000	$ 1,000,000	$ 300,000	$ 4,600,000