Derivatives (Schedule Of Open Forward Positions On Outstanding Put Agreements) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2012 bbl	Dec. 31, 2011 bbl
Derivative [Line Items]
Current Asset Fair Value	37	142
1st Qtr 2012 [Member]
Derivative [Line Items]
Current Asset Fair Value		2
2nd Qtr 2012 [Member]
Derivative [Line Items]
Current Asset Fair Value		23
3rd Qtr 2012 [Member]
Derivative [Line Items]
Current Asset Fair Value	5	48
4th Qtr 2012 [Member]
Derivative [Line Items]
Current Asset Fair Value	32	69
Scenario, Forecast [Member] | 1st Qtr 2012 [Member]
Derivative [Line Items]
Monthly Volume		10,000
Total Quarterly Volume		30,000
Floor NYMEX		65.00
Scenario, Forecast [Member] | 2nd Qtr 2012 [Member]
Derivative [Line Items]
Monthly Volume		10,000
Total Quarterly Volume		30,000
Floor NYMEX		65.00
Scenario, Forecast [Member] | 3rd Qtr 2012 [Member]
Derivative [Line Items]
Monthly Volume	10,000	10,000
Total Quarterly Volume	30,000	30,000
Floor NYMEX	65.00	65.00
Scenario, Forecast [Member] | 4th Qtr 2012 [Member]
Derivative [Line Items]
Monthly Volume	10,000	10,000
Total Quarterly Volume	30,000	30,000
Floor NYMEX	65.00	65.00