Supplemental Disclosures (Details 1) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Supplemental disclosures of cash flow information
Cash paid for interest expense, net of amounts capitalized	$ 3,667	$ 2,110
Asset retirement obligations related to mineral properties	3,305	889
Asset retirement obligations related to support equipment and facilities	132	4
Increase (decrease) in liabilities for oil and natural gas properties capital expenditures	43,692	(6,288)
Increase (decrease) in liabilities for support equipment and facilities	2,488	(1,100)
Increase in liabilities for accrued cost to issue equity	0	456
Issuance of restricted stock units for Board and advisor services	313	186
Issuance of common stock for advisor services	13	25
Stock-based compensation expense recognized as liability	789	715
Transfer of inventory from oil and natural gas properties	$ 300	$ 201