Derivatives (Summary Of Derivative Instruments Contracts) (Details)	Jun. 30, 2021 MMBTU $ / MMBTU $ / bbl bbl
Natural Gas Costless Collars [Member] | Remaining 2021 [Member]
Derivative [Line Items]
Contract total volume - Gas/Natural gas | MMBTU	1,462,000
Natural Gas Costless Collars [Member] | Remaining 2021 [Member] | Minimum [Member]
Derivative [Line Items]
Contract average price	2.37
Natural Gas Costless Collars [Member] | Remaining 2021 [Member] | Maximum [Member]
Derivative [Line Items]
Contract average price	3.06
Natural Gas Costless Collars [Member] | 2022 [Member]
Derivative [Line Items]
Contract total volume - Gas/Natural gas | MMBTU	2,540,500
Natural Gas Costless Collars [Member] | 2022 [Member] | Minimum [Member]
Derivative [Line Items]
Contract average price	2.42
Natural Gas Costless Collars [Member] | 2022 [Member] | Maximum [Member]
Derivative [Line Items]
Contract average price	3.17
Natural Gas Costless Collars [Member] | 2023 [Member]
Derivative [Line Items]
Contract total volume - Gas/Natural gas | MMBTU	166,000
Natural Gas Costless Collars [Member] | 2023 [Member] | Minimum [Member]
Derivative [Line Items]
Contract average price	2.37
Natural Gas Costless Collars [Member] | 2023 [Member] | Maximum [Member]
Derivative [Line Items]
Contract average price	3.26
Natural Gas Fixed Price Swaps [Member] | Remaining 2021 [Member]
Derivative [Line Items]
Contract total volume - Gas/Natural gas | MMBTU	742,000
Contract average price	2.81
Natural Gas Fixed Price Swaps [Member] | 2022 [Member]
Derivative [Line Items]
Contract total volume - Gas/Natural gas | MMBTU	547,500
Contract average price	2.73
Natural Gas Fixed Price Swaps [Member] | 2023 [Member]
Derivative [Line Items]
Contract total volume - Gas/Natural gas | MMBTU	84,000
Contract average price	2.56
Oil Costless Collars [Member] | Remaining 2021 [Member]
Derivative [Line Items]
Contract total volume - Oil | bbl	15,000
Oil Costless Collars [Member] | Remaining 2021 [Member] | Minimum [Member]
Derivative [Line Items]
Contract average price | $ / bbl	36.87
Oil Costless Collars [Member] | Remaining 2021 [Member] | Maximum [Member]
Derivative [Line Items]
Contract average price | $ / bbl	45.76
Oil Costless Collars [Member] | 2022 [Member]
Derivative [Line Items]
Contract total volume - Oil | bbl	68,500
Oil Costless Collars [Member] | 2022 [Member] | Minimum [Member]
Derivative [Line Items]
Contract average price | $ / bbl	40.25
Oil Costless Collars [Member] | 2022 [Member] | Maximum [Member]
Derivative [Line Items]
Contract average price | $ / bbl	50.35
Oil Fixed Price Swaps [Member] | Remaining 2021 [Member]
Derivative [Line Items]
Contract average price | $ / bbl	40.27
Contract total volume - Oil | bbl	63,000
Oil Fixed Price Swaps [Member] | 2022 [Member]
Derivative [Line Items]
Contract average price | $ / bbl	41.51
Contract total volume - Oil | bbl	59,000