Supplementary Information on Oil and Gas Producing Activities (Unaudited) (Details Textual)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Supplementary Information on Oil and Gas Producing Activities (Textual) [Abstract]
Discount Rate to determine future cash flows	10.00%	10.00%
Price for oil and gas		48.65
Oil [Member]
Supplementary Information on Oil and Gas Producing Activities (Textual) [Abstract]
Price for oil and gas	94.71	89.73
Gas [Member]
Supplementary Information on Oil and Gas Producing Activities (Textual) [Abstract]
Price for oil and gas	2.76	4.24
NGL [Member]
Supplementary Information on Oil and Gas Producing Activities (Textual) [Abstract]
Price for oil and gas	34.00