Derivative Contracts Schedule Of Commodity Derivative Contracts (Details) MMBTU in Millions	3 Months Ended
	Mar. 31, 2016 USD ($) MMBTU $ / MMBTU
Gas Swaps [Member] | Production [Member] | Year 2016 [Member] | NYMEX HH [Member]
Derivative [Line Items]
Derivative Volumes	42.2
Average Swap Price per Unit | $	$ 2.80
Gas Swaps [Member] | Production [Member] | Year 2016 [Member] | IFNPCR [Member]
Derivative [Line Items]
Derivative Volumes	55.0
Average Swap Price per Unit | $	$ 2.53
Gas Swaps [Member] | Production [Member] | Year 2017 [Member] | NYMEX HH [Member]
Derivative [Line Items]
Derivative Volumes	73.0
Average Swap Price per Unit | $	$ 2.75
Gas Swaps [Member] | Production [Member] | Year 2017 [Member] | IFNPCR [Member]
Derivative [Line Items]
Derivative Volumes	32.9
Average Swap Price per Unit | $	$ 2.51
Gas Swaps [Member] | Production [Member] | Year 2018 [Member] | NYMEX HH [Member]
Derivative [Line Items]
Derivative Volumes	7.3
Average Swap Price per Unit | $	$ 2.80
Gas Swaps [Member] | Storage [Member] | Year 2016 [Member] | IFNPCR [Member]
Derivative [Line Items]
Derivative Volumes	1.9
Average Swap Price per Unit | $	$ 2.57
Gas Swaps [Member] | Storage [Member] | Year 2017 [Member] | IFNPCR [Member]
Derivative [Line Items]
Derivative Volumes	0.2
Average Swap Price per Unit | $	$ 2.69
Oil Swaps [Member] | Production [Member] | Year 2016 (April through June) [Member] | NYMEX WTI [Member]
Derivative [Line Items]
Derivative Volumes	1.7
Average Swap Price per Unit | $	$ 57.09
Oil Swaps [Member] | Production [Member] | Year 2016 (July through December) [Member] | NYMEX WTI [Member]
Derivative [Line Items]
Derivative Volumes	4.8
Average Swap Price per Unit | $	$ 52.44
Oil Swaps [Member] | Production [Member] | Year 2017 [Member] | NYMEX WTI [Member]
Derivative [Line Items]
Derivative Volumes	3.7
Average Swap Price per Unit | $	$ 51.71
Gas Collars [Member] | Production [Member] | Year 2016 [Member] | NYMEX HH [Member]
Derivative [Line Items]
Derivative Volumes	5.5
Derivative Average Price Floor | $	$ 2.75
Derivative Average Price Ceiling | $	$ 3.89
Gas Basis Swaps [Member] | Production [Member] | Year 2016 [Member] | NYMEX HH LESS IFNPCR [Member]
Derivative [Line Items]
Derivative Volumes	27.5
Weighted-Average Differential | $ / MMBTU	(0.16)
Gas Basis Swaps [Member] | Production [Member] | Year 2017 [Member] | NYMEX HH LESS IFNPCR [Member]
Derivative [Line Items]
Derivative Volumes	51.1
Weighted-Average Differential | $ / MMBTU	(0.18)
Gas Purchase Swaps [Member] | Storage [Member] | Year 2016 [Member] | IFNPCR [Member]
Derivative [Line Items]
Derivative Volumes	0.7
Average Swap Price per Unit | $	$ 1.73