Supplemental Disclosures (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Supplemental disclosures of cash flow information
Cash paid for interest expense, net of amounts capitalized	$ 1,359	$ 480
Asset retirement obligations related to mineral properties	626	125
Asset retirement obligations related to support equipment and facilities	30	28
(Decrease) Increase in liabilities for oil and natural gas properties capital expenditures	(15,590)	13,681
(Decrease) Increase in liabilities for support equipment and facilities	(1,065)	1,099
(Decrease) increase in liabilities for accrued cost to issue equity		(67)
Issuance of restricted stock units for Board and advisor services	47
Issuance of common stock for advisor services	8
Stock based compensation expense recognized as liability	30	(455)
Transfer of inventory to oil and natural gas properties	$ 211