Derivative Instruments (Schedule Of Crude Oil Derivative Positions) (Details) - Jun. 30, 2015 - Collars [Member] - Crude Oil [Member]	bbl / d $ / bbls
2015 [Member]
Derivative [Line Items]
Volumes (in Bbls/d) | bbl / d	16,200
Weighted Average Floor Price ($/Bbls)	50.00
Weighted Average Ceiling Price ($/Bbls)	67.34
2016 [Member]
Derivative [Line Items]
Volumes (in Bbls/d) | bbl / d	5,490
Weighted Average Floor Price ($/Bbls)	50.96
Weighted Average Ceiling Price ($/Bbls)	74.73