Summary of Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Summary of Significant Accounting Policies (Additional Textual) [Abstract]
Discount rate present value of future revenue from proved oil and gas reserves			10.00%
Full-cost ceiling impairment	$ 78,171	$ 229,026	$ 158,633	$ 296,153
Capitalized general and administrative costs	4,000	1,900	6,000	3,500
Capitalized interest expense	$ 1,700	$ 1,300	$ 2,200	$ 2,300
Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from earnings per share calculations because their effects would be anti-dilutive	2,900,000	2,500,000	2,900,000	2,500,000
Restricted Stock Units (RSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from earnings per share calculations because their effects would be anti-dilutive	100,000	100,000	100,000	100,000
Restricted Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from earnings per share calculations because their effects would be anti-dilutive	900,000	700,000	900,000	700,000
Preferred Shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from earnings per share calculations because their effects would be anti-dilutive		0		1,500,000