Derivative Financial Instruments (Schedule Of Open Natural Gas Derivative Positions) (Details)	9 Months Ended
	Sep. 30, 2016 MMBTU $ / MMBTU
FERC Henry Hub Price Swaps Natural Gas Q4 2016 [Member]
Derivative [Line Items]
Volume Per Day (MMBtu/d) | MMBTU	155,000
Weighted Average Price Swap	2.83
FERC Henry Hub Price Swaps Natural Gas Q1-Q4 2017 [Member]
Derivative [Line Items]
Volume Per Day (MMBtu/d) | MMBTU	145,384
Weighted Average Price Swap	3.06
FERC Henry Hub Price Swaps Natural Gas Q1-Q4 2018 [Member]
Derivative [Line Items]
Volume Per Day (MMBtu/d) | MMBTU	8,630
Weighted Average Price Swap	3.30
FERC Henry Hub Price Collars Natural Gas Q4 2016 [Member]
Derivative [Line Items]
Volume Per Day (MMBtu/d) | MMBTU	385,000
Weighted Average Floor Price	2.74
Weighted Average Ceiling Price	2.97
FERC Henry Hub Price Collars Natural Gas Q1-Q4 2017 [Member]
Derivative [Line Items]
Volume Per Day (MMBtu/d) | MMBTU	230,904
Weighted Average Floor Price	2.91
Weighted Average Ceiling Price	3.31
FERC Henry Hub Price Collars Natural Gas Q1-Q4 2018 [Member]
Derivative [Line Items]
Volume Per Day (MMBtu/d) | MMBTU	8,630
Weighted Average Floor Price	3.18
Weighted Average Ceiling Price	3.48
FERC Henry Hub Call Options Sold Natural Gas Q4 2016 [Member]
Derivative [Line Items]
Volume Per Day (MMBtu/d) | MMBTU	400,000
Weighted Average Call Option Sold Price	2.80
PEPL Basis Swaps Natural Gas Q4 2016 [Member]
Derivative [Line Items]
Volume Per Day (MMBtu/d) | MMBTU	175,000
Weighted Average Differential To Henry Hub	(0.34)
PEPL Basis Swaps Natural Gas Q1-Q4 2017 [Member]
Derivative [Line Items]
Volume Per Day (MMBtu/d) | MMBTU	150,000
Weighted Average Differential To Henry Hub	(0.34)
El Paso Natural Gas Basis Swaps Q4 2016 [Member]
Derivative [Line Items]
Volume Per Day (MMBtu/d) | MMBTU	125,000
Weighted Average Differential To Henry Hub	(0.12)
El Paso Natural Gas Basis Swaps Q1-Q4 2017 [Member]
Derivative [Line Items]
Volume Per Day (MMBtu/d) | MMBTU	80,000
Weighted Average Differential To Henry Hub	(0.13)
Houston Ship Channel Natural Gas Basis Swaps Q4 2016 [Member]
Derivative [Line Items]
Volume Per Day (MMBtu/d) | MMBTU	30,000
Weighted Average Differential To Henry Hub	0.11
Houston Ship Channel Natural Gas Basis Swaps Q1-Q4 2017 [Member]
Derivative [Line Items]
Volume Per Day (MMBtu/d) | MMBTU	35,000
Weighted Average Differential To Henry Hub	0.06
Transco Zone 4 Natural Gas Basis Swaps Q4 2016 [Member]
Derivative [Line Items]
Volume Per Day (MMBtu/d) | MMBTU	70,000
Weighted Average Differential To Henry Hub	0.01
Transco Zone 4 Natural Gas Basis Swaps Q1-Q4 2017 [Member]
Derivative [Line Items]
Volume Per Day (MMBtu/d) | MMBTU	205,000
Weighted Average Differential To Henry Hub	0.03