Supplemental Disclosures (Details 1) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Supplemental disclosures of cash flow information
Cash paid for interest expense, net of amounts capitalized	$ 3,058	$ 1,817
Asset retirement obligations related to mineral properties	2,343	751
Asset retirement obligations related to support equipment and facilities	132	4
Increase (decrease) in liabilities for oil and natural gas properties capital expenditures	34,444	(6,859)
Increase (decrease) in liabilities for support equipment and facilities	293	(914)
Increase in liabilities for accrued cost to issue equity	86	0
Issuance of restricted stock units for Board and advisor services	197	87
Issuance of common stock for advisor services	10	17
Stock-based compensation expense recognized as liability	1,200	284
Transfer of inventory from oil and natural gas properties	$ 133	$ 191