Hedging Program and Derivatives (Details) (USD $)													3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Commodity Price Derivatives [Member]	Dec. 31, 2012 Commodity Price Derivatives [Member]	Mar. 31, 2013 Commodity Price Derivatives [Member] Derivative Assets - Current [Member]	Dec. 31, 2012 Commodity Price Derivatives [Member] Derivative Assets - Current [Member]	Mar. 31, 2013 Commodity Price Derivatives [Member] Derivative Assets - Noncurrent [Member]	Dec. 31, 2012 Commodity Price Derivatives [Member] Derivative Assets - Noncurrent [Member]	Mar. 31, 2013 Commodity Price Derivatives [Member] Derivative Liabilities - Current [Member]	Dec. 31, 2012 Commodity Price Derivatives [Member] Derivative Liabilities - Current [Member]	Mar. 31, 2013 Commodity Price Derivatives [Member] Derivative Liabilities - Noncurrent [Member]	Dec. 31, 2012 Commodity Price Derivatives [Member] Derivative Liabilities - Noncurrent [Member]	Mar. 31, 2013 Oil - WTI [Member] 2013 [Member] bbl	Mar. 31, 2013 Oil - WTI [Member] 2014 [Member] bbl	Mar. 31, 2013 Oil - WTI [Member] 2015 [Member] bbl	Mar. 31, 2013 Oil - WTI [Member] 2016 [Member] bbl	Mar. 31, 2013 Oil - WTI [Member] 2017 [Member] bbl	Mar. 31, 2013 Oil - Brent [Member] 2013 [Member] bbl	Mar. 31, 2013 Oil - Brent [Member] 2014 [Member] bbl	Mar. 31, 2013 Oil - Brent [Member] 2015 [Member] bbl	Mar. 31, 2013 Oil - Brent [Member] 2016 [Member] bbl	Mar. 31, 2013 Oil - Brent [Member] 2017 [Member] bbl
Oil and Gas Delivery Commitments and Contracts [Line Items]
Daily Volume (Bbl)													1,007	687	560	963	500	510	505	500	0	0
Swap Price (per Bbl)													84.76	94.16	83.03	84.10	84.18	105.00	100.56	97.04	0	0
Derivatives, Fair Value [Line Items]
Fair value of commodity derivative contract	$ 7,000,000
Impact of derivative contracts on balance sheet [Abstract]
Derivative asset - current	92,000	41,000			92,000	41,000
Derivative asset - noncurrent	381,000	594,000					381,000	594,000
Derivative assets, Total			473,000	635,000
Derivative liability - current	4,216,000	3,462,000							4,216,000	3,462,000
Derivative liability - noncurrent	3,244,000	3,568,000									3,244,000	3,568,000
Derivative liabilities, Total			$ 7,460,000	$ 7,030,000