Summary of Significant Accounting Policies (Details Textual) (USD $)	3 Months Ended		6 Months Ended									6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013	May 01, 2013	Jul. 15, 2014 Subsequent Event [Member] acre	Jun. 30, 2014 Senior Notes Due Two Thousand Seven Teen [Member]	Jun. 30, 2014 Senior Notes Due Two Thousand Twenty [Member]	Jun. 30, 2014 Senior Notes Due 2022 [Member]	Jun. 30, 2014 Line of Credit [Member]	Jun. 30, 2014 Minimum [Member]	Jun. 30, 2014 Maximum [Member]
Accounts Receivable (Textual) [Abstract]
Allowance for doubtful accounts receivable, current	$ 100,000		$ 100,000		$ 100,000
Trade Accounts Receivable, Gross	59,000,000		59,000,000		56,900,000
Accounts receivable related to joint interest owners	1,100,000		1,100,000		1,600,000
Severance Tax Receivable	7,700,000		7,700,000		11,600,000
Other Receivables	800,000		800,000		800,000
Summary of Significant Accounting Policies (Textual) [Abstract]
Acreage Sold in Oil and Gas Properties							8,300
Interest Sold in Oil and Gas Properties							36.00%
Significant Acquisitions and Disposals, Acquisition Costs or Sale Proceeds						5,800,000	175,000,000
Cash Paid at Closing of Oil and Gas Properties							125,000,000
Cash Carry of Field Development Costs							50,000,000
Total capitalized internal costs	6,900,000	7,500,000	14,100,000	16,000,000
Total capitalized interest cost on unproved properties	1,200,000	1,900,000	2,500,000	3,800,000
Property, Plant and Equipment, Useful Life												2 years	20 years
Discount rate for estimated future net revenues from proved properties			10.00%
Net gain (loss) on derivative activities	(2,700,000)	1,500,000
Unrealized Gain (Loss) on Derivatives	(1,200,000)
Derivative Asset, Fair Value, Gross Asset	200,000		200,000
Derivative Liability, Fair Value, Gross Liability	3,100,000		3,100,000
Derivative, Fair Value, Net	(2,900,000)		(2,900,000)
Receivables from settled derivatives	100,000		100,000
Liabilities, Fair Value Disclosure	1,300,000		1,300,000
Percentage of working interest in wells			100.00%
Total amount of supervision fees charged to wells	3,000,000	3,300,000	5,700,000	6,100,000
Inventories carried at cost	3,000,000		3,000,000		3,500,000
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation	200,000		1,900,000
Outstanding checks included in trade accounts payable	7,500,000		7,500,000		26,100,000
Restricted Cash and Cash Equivalents, Current	12,500,000		12,500,000
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	13,717,000		13,717,000		15,859,000
Debt Issuance Costs (Textual) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage								7.125%	8.875%	7.875%
Balance of issuance costs for credit facility								$ 1,500,000	$ 3,300,000	$ 6,200,000	$ 2,900,000