Derivatives (Summary Of Derivative Instruments Contracts) (Details)	Mar. 31, 2020 MMBTU $ / MMBTU $ / bbl bbl
Natural Gas Costless Collars [Member] | Derivative Contract Period One [Member]
Derivative [Line Items]
Production volume covered per month - Gas/Natural gas | MMBTU	10,000
Natural Gas Costless Collars [Member] | Derivative Contract Period One [Member] | Minimum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU	2.20
Natural Gas Costless Collars [Member] | Derivative Contract Period One [Member] | Maximum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU	2.59
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Two [Member]
Derivative [Line Items]
Production volume covered per month - Gas/Natural gas | MMBTU	80,000
Contract price | $ / MMBTU	2.750
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Three [Member]
Derivative [Line Items]
Production volume covered per month - Gas/Natural gas | MMBTU	10,000
Contract price | $ / MMBTU	2.405
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Four [Member]
Derivative [Line Items]
Production volume covered per month - Gas/Natural gas | MMBTU	10,000
Contract price | $ / MMBTU	2.661
Oil Costless Collars [Member] | Derivative Contract Period Five [Member]
Derivative [Line Items]
Production volume covered per month - Oil | bbl	2,000
Oil Costless Collars [Member] | Derivative Contract Period Five [Member] | Minimum [Member]
Derivative [Line Items]
Contract price	65.00
Oil Costless Collars [Member] | Derivative Contract Period Five [Member] | Maximum [Member]
Derivative [Line Items]
Contract price	76.15
Oil Costless Collars [Member] | Derivative Contract Period Six [Member]
Derivative [Line Items]
Production volume covered per month - Oil | bbl	2,000
Oil Costless Collars [Member] | Derivative Contract Period Six [Member] | Minimum [Member]
Derivative [Line Items]
Contract price	60.00
Oil Costless Collars [Member] | Derivative Contract Period Six [Member] | Maximum [Member]
Derivative [Line Items]
Contract price	67.00
Oil Costless Collars [Member] | Derivative Contract Period Seven [Member]
Derivative [Line Items]
Production volume covered per month - Oil | bbl	2,000
Oil Costless Collars [Member] | Derivative Contract Period Seven [Member] | Minimum [Member]
Derivative [Line Items]
Contract price	55.00
Oil Costless Collars [Member] | Derivative Contract Period Seven [Member] | Maximum [Member]
Derivative [Line Items]
Contract price	62.00
Oil Fixed Price Swaps [Member] | Derivative Contract Period Eight [Member]
Derivative [Line Items]
Contract price	55.28
Production volume covered per month - Oil | bbl	2,000
Oil Fixed Price Swaps [Member] | Derivative Contract Period Nine [Member]
Derivative [Line Items]
Contract price	58.65
Production volume covered per month - Oil | bbl	2,000
Oil Fixed Price Swaps [Member] | Derivative Contract Period Ten [Member]
Derivative [Line Items]
Contract price	60.00
Production volume covered per month - Oil | bbl	2,000
Oil Fixed Price Swaps [Member] | Derivative Contract Period Eleven [Member]
Derivative [Line Items]
Contract price	58.05
Production volume covered per month - Oil | bbl	2,000
Oil Fixed Price Swaps [Member] | Derivative Contract Period Twelve [Member]
Derivative [Line Items]
Contract price	58.10
Production volume covered per month - Oil | bbl	2,000