Summary of Significant Accounting Policies (Details Textual) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Jul. 15, 2014 acre	Dec. 31, 2013
Summary of Significant Accounting Policies (Textual) [Abstract]
Total capitalized internal costs	$ 6,900,000	$ 7,900,000	$ 20,900,000	$ 23,900,000
Total capitalized interest cost on unproved properties	1,200,000	1,800,000	3,700,000	5,600,000
Discount rate for estimated future net revenues from proved properties			10.00%
Allowance for doubtful accounts receivable, current	400,000		400,000			100,000
Trade Accounts Receivable, Gross	51,900,000		51,900,000			56,900,000
Accounts receivable related to joint interest owners	1,900,000		1,900,000			1,600,000
Severance Tax Receivable	7,900,000		7,900,000			11,600,000
Other Receivables	1,700,000		1,700,000			800,000
Net gain (loss) on derivative activities	5,000,000	(2,000,000)	(2,700,000)	(800,000)
Non-Cash Fair Value Adjustment for Derivatives	1,200,000
Receivables from settled derivatives	1,000,000		1,000,000
Liabilities, Fair Value Disclosure	100,000		100,000
Derivative, Fair Value, Net	100,000		100,000			(100,000)
Percentage of working interest in wells			100.00%
Total amount of supervision fees charged to wells	3,500,000	2,800,000	9,200,000	8,900,000
Inventories carried at cost	3,100,000		3,100,000			3,500,000
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation	200,000		2,100,000
Outstanding checks included in trade accounts payable	9,600,000		9,600,000			26,100,000
Acreage Sold in Oil and Gas Properties					8,300
Interest Sold in Oil and Gas Properties					36.00%
Restricted Cash and Cash Equivalents, Current	34,500,000		34,500,000
Restricted Cash Attributable to Company	11,800,000		11,800,000
Increase in Restricted Cash in Operating Activities	29,800,000
Decrease in Restricted Cash in Operating Activities	7,100,000
Restricted cash and cash equivalents included in other long term assets	1,000,000		1,000,000			1,000,000
Asset Retirement Obligation - current portion	13,292,000		13,292,000			15,859,000
Other Current Assets [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Derivative Asset, Fair Value, Gross Asset	700,000		700,000
Other Current Liabilities [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Derivative Liability, Fair Value, Gross Liability	500,000		500,000
Other Noncurrent Liabilities [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Derivative Liability, Fair Value, Gross Liability	100,000		100,000
Senior Notes [Member] | Senior Notes Due 2017 [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	7.125%		7.125%
Balance of issuance costs for credit facility	1,400,000		1,400,000
Senior Notes [Member] | Senior Notes Due 2020 [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	8.875%		8.875%
Balance of issuance costs for credit facility	3,200,000		3,200,000
Senior Notes [Member] | Senior Notes Due 2022 [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	7.875%		7.875%
Balance of issuance costs for credit facility	6,100,000		6,100,000
Line of Credit [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Balance of issuance costs for credit facility	$ 2,500,000		$ 2,500,000
Minimum [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Property, Plant and Equipment, Useful Life			2 years
Maximum [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Property, Plant and Equipment, Useful Life			20 years