Summary of Significant Accounting Policies (Details Textual) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	May 01, 2013	Dec. 31, 2012
Accounts Receivable (Textual) [Abstract]
Allowance for doubtful accounts receivable, current	$ 100,000		$ 100,000			$ 100,000
Trade Accounts Receivable, Gross	52,100,000		52,100,000			53,900,000
Accounts receivable related to joint interest owners	3,100,000		3,100,000			3,600,000
Severance Tax Receivable	11,800,000		11,800,000			5,800,000
Other Receivables	1,800,000		1,800,000			4,000,000
Summary of Significant Accounting Policies (Textual) [Abstract]
Total capitalized internal costs	7,900,000	7,800,000	23,900,000	23,900,000
Total capitalized interest cost on unproved properties	1,800,000	2,000,000	5,600,000	6,000,000
Discount rate for estimated future net revenues from proved properties			10.00%
Net gain (loss) on derivative activities	(2,000,000)	200,000	(800,000)	2,500,000
Unrealized Gain (Loss) on Derivatives	(700,000)		100,000
Price Risk Cash Flow Hedge Asset, at Fair Value	1,400,000		1,400,000
Price Risk Cash Flow Hedge Liability, at Fair Value	(600,000)		(600,000)
Price Risk Cash Flow Hedge Derivative, at Fair Value, Net	800,000		800,000
Receivables from settled derivatives	400,000		400,000
Payables for settled derivatives	400,000		400,000
Percentage of working interest in wells			100.00%
Total amount of supervision fees charged to wells	2,800,000	2,900,000	8,900,000	8,600,000
Inventories carried at cost	2,900,000		2,900,000			5,600,000
Outstanding checks included in trade accounts payable	11,400,000		11,400,000			13,300,000
Maturity Period of Cash and cash Equivalents			3 months
Restricted cash and cash equivalents included in other long term assets	1,000,000		1,000,000			1,000,000
Reduction of asset retirement obligation due to sale of properties					11,300,000
Asset Retirement Obligation - current portion	8,119,000		8,119,000			7,134,000
Senior Notes Due Two Thousand Seven Teen [Member]
Debt Issuance Costs (Textual) [Abstract]
Balance of issuance costs for credit facility	1,900,000		1,900,000
Debt Instrument, Interest Rate, Stated Percentage	7.125%		7.125%
Senior Notes Due Two Thousand Twenty [Member]
Debt Issuance Costs (Textual) [Abstract]
Balance of issuance costs for credit facility	3,700,000		3,700,000
Debt Instrument, Interest Rate, Stated Percentage	8.875%		8.875%
Senior Notes Due 2022 [Member]
Debt Issuance Costs (Textual) [Abstract]
Balance of issuance costs for credit facility	6,700,000		6,700,000
Debt Instrument, Interest Rate, Stated Percentage	7.875%		7.875%
Line of Credit [Member]
Debt Issuance Costs (Textual) [Abstract]
Balance of issuance costs for credit facility	3,600,000		3,600,000
Maximum [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Property, Plant and Equipment, Useful Life			20 years
Minimum [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Property, Plant and Equipment, Useful Life			2 years
Natural Gas [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Price Risk Cash Flow Hedge Asset, at Fair Value	700,000		700,000
Natural Gas [Member] | Derivative, Collar [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Future Gas Production Hedged in MMBTU (Energy Item Type)	1,180,000		1,180,000
Derivative, Floor Strike Price	3.75		3.75
Derivative, Call Strike Price	5.08		5.08
Natural Gas [Member] | Derivative, Participating Collar [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Future Gas Production Hedged in MMBTU (Energy Item Type)	1,200,000		1,200,000
Derivative, Floor Strike Price	4.00		4.00
Derivative, Call Strike Price	5.00		5.00
Derivative, particpating collar (cap price)	6.00		6.00
Oil [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Price Risk Cash Flow Hedge Asset, at Fair Value	700,000		700,000
Price Risk Cash Flow Hedge Liability, at Fair Value	$ (600,000)		$ (600,000)
Oil [Member] | Derivative, Floor [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Future Production Hedged (Oil)	252,000		252,000
Derivative, Floor Strike Price	97.00		97.00
Oil [Member] | Derivative, Call [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Future Production Hedged (Oil)	282,000		282,000
Oil [Member] | Derivative, Call [Member] | Maximum [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Derivative, Call Strike Price	116.60		116.60
Oil [Member] | Derivative, Call [Member] | Minimum [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Derivative, Call Strike Price	110.70		110.70
Oil [Member] | Derivative, Collar [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Future Production Hedged (Oil)	477,000		477,000
Derivative, Floor Strike Price	90.00		90.00
Derivative, Call Strike Price	107.35		107.35