Commitments and Contingencies (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 sqft	Dec. 31, 2013	Dec. 31, 2012	May 15, 2008
Long-term Purchase Commitment [Line Items]
Effective base rent per square foot per year	20.28
Rent expense, including fees for operating expenses and consumption of electricity	$ 0.9	$ 0.8	$ 0.6
Effective date of which company entered into agreement	Sep. 01, 2012
Natural gas processing and transportation agreement	5 years
Minimum delivery commitment to avoid paying gas deficiency fee	80.00%
Transportation and processing fees under the agreement	5.8	5.3
Payments for Construction in Process	2.1
Minimum outstanding commitments	21.0
Royalty owner undivided interest in mineral				16.70%
Lease agreements [Member]
Long-term Purchase Commitment [Line Items]
Office space of headquarters	40,071
Term Of Old Contract Drilling Rig [Member]
Long-term Purchase Commitment [Line Items]
Term of new contract drilling rig	one year
Drilling Rig Commitments [Member]
Long-term Purchase Commitment [Line Items]
Maximum termination outstanding obligations of contracts	50.4
Construction Contracts [Member]
Long-term Purchase Commitment [Line Items]
Maximum termination outstanding obligations of contracts	$ 17.0