Summary of Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Other income	$ (141)	$ 564	$ (17)	$ 637
Third-party midstream services revenues	1,566	569	2,956	1,384
Production taxes and marketing	12,388	9,426	30,846	26,734
Plant and other midstream services operating	1,449	1,450	3,537	2,772
Lease operating expense	14,605	13,466	$ 41,300	40,140
Discount rate present value of future revenue from proved oil and gas reserves			10.00%
Full-cost ceiling impairment	0	285,721	$ 158,633	581,874
Capitalized general and administrative costs	4,300	1,400	10,300	4,900
Capitalized interest expense	$ 700	500	$ 2,900	2,900
Reclassification from Other Income to Third-Party Midstream Services Revenue [Member] | Restatement Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Other income		(400)		(1,200)
Third-party midstream services revenues		500		1,300
Reclassification from Production Taxes and Marketing Expenses to Third-Party Midstream Services Revenues [Member] | Restatement Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Third-party midstream services revenues		100		100
Production taxes and marketing		(100)		(100)
Reclassification from Lease Operating Expenses to Plant and Other Midstream Services Operating Expenses [Member] | Restatement Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Plant and other midstream services operating		1,500		2,800
Lease operating expense		$ (1,500)		$ (2,800)