Summary Of Significant Accounting Policies (Summary Of Derivative Instruments Contracts) (Details)	Sep. 30, 2018 MMBTU $ / MMBTU $ / bbl bbl	Sep. 30, 2017 MMBTU $ / MMBTU $ / bbl bbl
Natural Gas Costless Collars [Member] | Derivative Contract Period One [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU	40,000	50,000
Natural Gas Costless Collars [Member] | Derivative Contract Period One [Member] | Minimum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU	2.75	2.80
Natural Gas Costless Collars [Member] | Derivative Contract Period One [Member] | Maximum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU	3.35	3.47
Natural Gas Costless Collars [Member] | Derivative Contract Period Two [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU	40,000	50,000
Natural Gas Costless Collars [Member] | Derivative Contract Period Two [Member] | Minimum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU	2.75	3.00
Natural Gas Costless Collars [Member] | Derivative Contract Period Two [Member] | Maximum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU	3.30	3.35
Natural Gas Costless Collars [Member] | Derivative Contract Period Three [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU	50,000	50,000
Natural Gas Costless Collars [Member] | Derivative Contract Period Three [Member] | Minimum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU	2.80	2.80
Natural Gas Costless Collars [Member] | Derivative Contract Period Three [Member] | Maximum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU	3.15	3.35
Natural Gas Costless Collars [Member] | Derivative Contract Period Four [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU		50,000
Natural Gas Costless Collars [Member] | Derivative Contract Period Four [Member] | Minimum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU		2.75
Natural Gas Costless Collars [Member] | Derivative Contract Period Four [Member] | Maximum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU		3.35
Natural Gas Costless Collars [Member] | Derivative Contract Period Five [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU		30,000
Natural Gas Costless Collars [Member] | Derivative Contract Period Five [Member] | Minimum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU		3.00
Natural Gas Costless Collars [Member] | Derivative Contract Period Five [Member] | Maximum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU		3.65
Natural Gas Costless Collars [Member] | Derivative Contract Period Six [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU		50,000
Natural Gas Costless Collars [Member] | Derivative Contract Period Six [Member] | Minimum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU		3.00
Natural Gas Costless Collars [Member] | Derivative Contract Period Six [Member] | Maximum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU		3.60
Natural Gas Costless Collars [Member] | Derivative Contract Period Seven [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU		50,000
Natural Gas Costless Collars [Member] | Derivative Contract Period Seven [Member] | Minimum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU		3.20
Natural Gas Costless Collars [Member] | Derivative Contract Period Seven [Member] | Maximum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU		3.65
Natural Gas Costless Collars [Member] | Derivative Contract Period Eight [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU		100,000
Natural Gas Costless Collars [Member] | Derivative Contract Period Eight [Member] | Minimum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU		3.50
Natural Gas Costless Collars [Member] | Derivative Contract Period Eight [Member] | Maximum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU		3.95
Natural Gas Costless Collars [Member] | Derivative Contract Period Ten [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU		40,000
Natural Gas Costless Collars [Member] | Derivative Contract Period Ten [Member] | Minimum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU		2.75
Natural Gas Costless Collars [Member] | Derivative Contract Period Ten [Member] | Maximum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU		3.35
Natural Gas Costless Collars [Member] | Derivative Contract Period Nine [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU		150,000
Natural Gas Costless Collars [Member] | Derivative Contract Period Nine [Member] | Minimum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU		3.40
Natural Gas Costless Collars [Member] | Derivative Contract Period Nine [Member] | Maximum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU		3.95
Natural Gas Costless Collars [Member] | Derivative Contract Period Eleven [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU		40,000
Natural Gas Costless Collars [Member] | Derivative Contract Period Eleven [Member] | Minimum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU		2.75
Natural Gas Costless Collars [Member] | Derivative Contract Period Eleven [Member] | Maximum [Member]
Derivative [Line Items]
Contract price | $ / MMBTU		3.30
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Four [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU	50,000
Contract price | $ / MMBTU	3.080
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Five [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU	40,000
Contract price | $ / MMBTU	2.910
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Six [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU	100,000
Contract price | $ / MMBTU	2.835
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Seven [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU	100,000
Contract price | $ / MMBTU	2.925
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Eight [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU	50,000
Contract price | $ / MMBTU	2.988
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Ten [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU	100,000
Contract price | $ / MMBTU	2.867
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Nine [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU	50,000
Contract price | $ / MMBTU	3.065
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Thirteen [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU		50,000
Contract price | $ / MMBTU		3.070
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Twelve [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU		25,000
Contract price | $ / MMBTU		3.100
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Fourteen [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU		50,000
Contract price | $ / MMBTU		3.210
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Fifteen [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU		30,000
Contract price | $ / MMBTU		3.300
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Sixteen [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU		50,000
Contract price | $ / MMBTU		3.510
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Seventeen [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU		100,000
Contract price | $ / MMBTU		3.095
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Eighteen [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU		50,000
Contract price | $ / MMBTU		3.700
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Nineteen [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU		75,000
Contract price | $ / MMBTU		3.575
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Twenty [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU		100,000
Contract price | $ / MMBTU		3.520
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Twenty One [Member]
Derivative [Line Items]
Production volume covered per month - Natural Gas | MMBTU		50,000
Contract price | $ / MMBTU		3.080
Oil Costless Collars [Member] | Derivative Contract Period Thirteen [Member]
Derivative [Line Items]
Production volume covered per month - Oil | bbl	2,000
Oil Costless Collars [Member] | Derivative Contract Period Thirteen [Member] | Minimum [Member]
Derivative [Line Items]
Contract price	50.00
Oil Costless Collars [Member] | Derivative Contract Period Thirteen [Member] | Maximum [Member]
Derivative [Line Items]
Contract price	55.75
Oil Costless Collars [Member] | Derivative Contract Period Eleven [Member]
Derivative [Line Items]
Production volume covered per month - Oil | bbl	2,000
Oil Costless Collars [Member] | Derivative Contract Period Eleven [Member] | Minimum [Member]
Derivative [Line Items]
Contract price	47.50
Oil Costless Collars [Member] | Derivative Contract Period Eleven [Member] | Maximum [Member]
Derivative [Line Items]
Contract price	52.50
Oil Costless Collars [Member] | Derivative Contract Period Twenty Two [Member]
Derivative [Line Items]
Production volume covered per month - Oil | bbl		3,000
Oil Costless Collars [Member] | Derivative Contract Period Twenty Two [Member] | Minimum [Member]
Derivative [Line Items]
Contract price		50.00
Oil Costless Collars [Member] | Derivative Contract Period Twenty Two [Member] | Maximum [Member]
Derivative [Line Items]
Contract price		55.00
Oil Costless Collars [Member] | Derivative Contract Period Twelve [Member]
Derivative [Line Items]
Production volume covered per month - Oil | bbl	2,000
Oil Costless Collars [Member] | Derivative Contract Period Twelve [Member] | Minimum [Member]
Derivative [Line Items]
Contract price	48.00
Oil Costless Collars [Member] | Derivative Contract Period Twelve [Member] | Maximum [Member]
Derivative [Line Items]
Contract price	53.25
Oil Costless Collars [Member] | Derivative Contract Period Twenty Three [Member]
Derivative [Line Items]
Production volume covered per month - Oil | bbl		3,000
Oil Costless Collars [Member] | Derivative Contract Period Twenty Three [Member] | Minimum [Member]
Derivative [Line Items]
Contract price		52.00
Oil Costless Collars [Member] | Derivative Contract Period Twenty Three [Member] | Maximum [Member]
Derivative [Line Items]
Contract price		58.00
Oil Costless Collars [Member] | Derivative Contract Period Twenty Four [Member]
Derivative [Line Items]
Production volume covered per month - Oil | bbl		3,000
Oil Costless Collars [Member] | Derivative Contract Period Twenty Four [Member] | Minimum [Member]
Derivative [Line Items]
Contract price		53.00
Oil Costless Collars [Member] | Derivative Contract Period Twenty Four [Member] | Maximum [Member]
Derivative [Line Items]
Contract price		57.75
Oil Costless Collars [Member] | Derivative Contract Period Fourteen [Member]
Derivative [Line Items]
Production volume covered per month - Oil | bbl	3,000
Oil Costless Collars [Member] | Derivative Contract Period Fourteen [Member] | Minimum [Member]
Derivative [Line Items]
Contract price	50.00
Oil Costless Collars [Member] | Derivative Contract Period Fourteen [Member] | Maximum [Member]
Derivative [Line Items]
Contract price	58.00
Oil Costless Collars [Member] | Derivative Contract Period Twenty Five [Member]
Derivative [Line Items]
Production volume covered per month - Oil | bbl		2,000
Oil Costless Collars [Member] | Derivative Contract Period Twenty Five [Member] | Minimum [Member]
Derivative [Line Items]
Contract price		50.00
Oil Costless Collars [Member] | Derivative Contract Period Twenty Five [Member] | Maximum [Member]
Derivative [Line Items]
Contract price		57.50
Oil Costless Collars [Member] | Derivative Contract Period Fifteen [Member]
Derivative [Line Items]
Production volume covered per month - Oil | bbl	2,000
Oil Costless Collars [Member] | Derivative Contract Period Fifteen [Member] | Minimum [Member]
Derivative [Line Items]
Contract price	55.00
Oil Costless Collars [Member] | Derivative Contract Period Fifteen [Member] | Maximum [Member]
Derivative [Line Items]
Contract price	63.45
Oil Costless Collars [Member] | Derivative Contract Period Sixteen [Member]
Derivative [Line Items]
Production volume covered per month - Oil | bbl	1,000
Oil Costless Collars [Member] | Derivative Contract Period Sixteen [Member] | Minimum [Member]
Derivative [Line Items]
Contract price	50.00
Oil Costless Collars [Member] | Derivative Contract Period Sixteen [Member] | Maximum [Member]
Derivative [Line Items]
Contract price	60.00
Oil Costless Collars [Member] | Derivative Contract Period Seventeen [Member]
Derivative [Line Items]
Production volume covered per month - Oil | bbl	2,000
Oil Costless Collars [Member] | Derivative Contract Period Seventeen [Member] | Minimum [Member]
Derivative [Line Items]
Contract price	60.00
Oil Costless Collars [Member] | Derivative Contract Period Seventeen [Member] | Maximum [Member]
Derivative [Line Items]
Contract price	69.25
Oil Costless Collars [Member] | Derivative Contract Period Eighteen [Member]
Derivative [Line Items]
Production volume covered per month - Oil | bbl	3,000
Oil Costless Collars [Member] | Derivative Contract Period Eighteen [Member] | Minimum [Member]
Derivative [Line Items]
Contract price	60.00
Oil Costless Collars [Member] | Derivative Contract Period Eighteen [Member] | Maximum [Member]
Derivative [Line Items]
Contract price	70.75
Oil Costless Collars [Member] | Derivative Contract Period Nineteen [Member]
Derivative [Line Items]
Production volume covered per month - Oil | bbl	2,000
Oil Costless Collars [Member] | Derivative Contract Period Nineteen [Member] | Minimum [Member]
Derivative [Line Items]
Contract price	60.00
Oil Costless Collars [Member] | Derivative Contract Period Nineteen [Member] | Maximum [Member]
Derivative [Line Items]
Contract price	67.00
Oil Costless Collars [Member] | Derivative Contract Period Twenty Six [Member]
Derivative [Line Items]
Production volume covered per month - Oil | bbl		5,000
Oil Costless Collars [Member] | Derivative Contract Period Twenty Six [Member] | Minimum [Member]
Derivative [Line Items]
Contract price		45.00
Oil Costless Collars [Member] | Derivative Contract Period Twenty Six [Member] | Maximum [Member]
Derivative [Line Items]
Contract price		56.25
Oil Costless Collars [Member] | Derivative Contract Period Twenty Seven [Member]
Derivative [Line Items]
Production volume covered per month - Oil | bbl		2,000
Oil Costless Collars [Member] | Derivative Contract Period Twenty Seven [Member] | Minimum [Member]
Derivative [Line Items]
Contract price		47.50
Oil Costless Collars [Member] | Derivative Contract Period Twenty Seven [Member] | Maximum [Member]
Derivative [Line Items]
Contract price		52.75
Oil Costless Collars [Member] | Derivative Contract Period Twenty Eight [Member]
Derivative [Line Items]
Production volume covered per month - Oil | bbl		2,000
Oil Costless Collars [Member] | Derivative Contract Period Twenty Eight [Member] | Minimum [Member]
Derivative [Line Items]
Contract price		47.50
Oil Costless Collars [Member] | Derivative Contract Period Twenty Eight [Member] | Maximum [Member]
Derivative [Line Items]
Contract price		52.50
Oil Costless Collars [Member] | Derivative Contract Period Twenty Nine [Member]
Derivative [Line Items]
Production volume covered per month - Oil | bbl		2,000
Oil Costless Collars [Member] | Derivative Contract Period Twenty Nine [Member] | Minimum [Member]
Derivative [Line Items]
Contract price		48.00
Oil Costless Collars [Member] | Derivative Contract Period Twenty Nine [Member] | Maximum [Member]
Derivative [Line Items]
Contract price		53.25
Oil Fixed Price Swaps [Member] | Derivative Contract Period Twenty Two [Member]
Derivative [Line Items]
Contract price	54.14
Production volume covered per month - Oil | bbl	4,000
Oil Fixed Price Swaps [Member] | Derivative Contract Period Twenty Three [Member]
Derivative [Line Items]
Contract price	58.20
Production volume covered per month - Oil | bbl	2,000
Oil Fixed Price Swaps [Member] | Derivative Contract Period Twenty Four [Member]
Derivative [Line Items]
Contract price	59.69
Production volume covered per month - Oil | bbl	2,000
Oil Fixed Price Swaps [Member] | Derivative Contract Period Twenty Five [Member]
Derivative [Line Items]
Contract price	57.15
Production volume covered per month - Oil | bbl	2,000
Oil Fixed Price Swaps [Member] | Derivative Contract Period Twenty [Member]
Derivative [Line Items]
Contract price	50.72
Production volume covered per month - Oil | bbl	3,000
Oil Fixed Price Swaps [Member] | Derivative Contract Period Twenty One [Member]
Derivative [Line Items]
Contract price	52.02
Production volume covered per month - Oil | bbl	2,000
Oil Fixed Price Swaps [Member] | Derivative Contract Period Twenty Six [Member]
Derivative [Line Items]
Contract price	58.02
Production volume covered per month - Oil | bbl	3,000
Oil Fixed Price Swaps [Member] | Derivative Contract Period Twenty Seven [Member]
Derivative [Line Items]
Contract price	56.15
Production volume covered per month - Oil | bbl	1,000
Oil Fixed Price Swaps [Member] | Derivative Contract Period Twenty Eight [Member]
Derivative [Line Items]
Contract price	56.71
Production volume covered per month - Oil | bbl	2,000
Oil Fixed Price Swaps [Member] | Derivative Contract Period Twenty Nine [Member]
Derivative [Line Items]
Contract price	58.56
Production volume covered per month - Oil | bbl	1,000
Oil Fixed Price Swaps [Member] | Derivative Contract Period Thirty [Member]
Derivative [Line Items]
Contract price	56.85	53.89
Production volume covered per month - Oil | bbl	2,000	3,000
Oil Fixed Price Swaps [Member] | Derivative Contract Period Thirty One [Member]
Derivative [Line Items]
Contract price		54.20
Production volume covered per month - Oil | bbl		2,000
Oil Fixed Price Swaps [Member] | Derivative Contract Period Thirty Two [Member]
Derivative [Line Items]
Contract price		54.00
Production volume covered per month - Oil | bbl		4,000
Oil Fixed Price Swaps [Member] | Derivative Contract Period Thirty Three [Member]
Derivative [Line Items]
Contract price		51.25
Production volume covered per month - Oil | bbl		4,000
Oil Fixed Price Swaps [Member] | Derivative Contract Period Thirty Four []Member]
Derivative [Line Items]
Contract price		50.72
Production volume covered per month - Oil | bbl		3,000
Oil Fixed Price Swaps [Member] | Derivative Contract Period Thirty Five [Member]
Derivative [Line Items]
Contract price		52.02
Production volume covered per month - Oil | bbl		2,000