Derivative Contracts Schedule Of Commodity Derivative Contracts (Details) MMBTU in Millions	6 Months Ended
	Jun. 30, 2016 USD ($) MMBTU $ / MMBTU
Gas Swaps [Member] | Production [Member] | Year 2016 [Member] | NYMEX HH [Member]
Derivative [Line Items]
Derivative Volumes	29.4
Average Swap Price per Unit | $	$ 2.78
Gas Swaps [Member] | Production [Member] | Year 2016 [Member] | IFNPCR [Member]
Derivative [Line Items]
Derivative Volumes	36.8
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	2.3
Average Swap Price per Unit | $	$ 2.57
Gas Swaps [Member] | Storage [Member] | Year 2017 [Member] | IFNPCR [Member]
Derivative [Line Items]
Derivative Volumes	2.4
Average Swap Price per Unit | $	$ 2.77
Oil Swaps [Member] | Production [Member] | Year 2016 [Member] | NYMEX WTI [Member]
Derivative [Line Items]
Derivative Volumes	6.1
Average Swap Price per Unit | $	$ 51.24
Oil Swaps [Member] | Production [Member] | Year 2017 [Member] | NYMEX WTI [Member]
Derivative [Line Items]
Derivative Volumes	9.1
Average Swap Price per Unit | $	$ 50.76
Oil Swaps [Member] | Production [Member] | Year 2018 [Member] | NYMEX WTI [Member]
Derivative [Line Items]
Derivative Volumes	1.1
Average Swap Price per Unit | $	$ 53.72
Gas Collars [Member] | Production [Member] | Year 2016 [Member] | NYMEX HH [Member]
Derivative [Line Items]
Derivative Volumes	3.7
Derivative Average Price Floor | $	$ 2.75
Derivative Average Price Ceiling | $	$ 3.89
Gas Collars [Member] | Production [Member] | Year 2017 [Member] | NYMEX HH [Member]
Derivative [Line Items]
Derivative Volumes	11.0
Derivative Average Price Floor | $	$ 2.50
Derivative Average Price Ceiling | $	$ 3.50
Gas Basis Swaps [Member] | Production [Member] | Year 2016 [Member] | NYMEX HH LESS IFNPCR [Member]
Derivative [Line Items]
Derivative Volumes	18.4
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 Basis Swaps [Member] | Production [Member] | Year 2018 [Member] | NYMEX HH LESS IFNPCR [Member]
Derivative [Line Items]
Derivative Volumes	7.3
Weighted-Average Differential | $ / MMBTU	(0.16)
Gas Purchase Swaps [Member] | Storage [Member] | Year 2016 [Member] | IFNPCR [Member]
Derivative [Line Items]
Derivative Volumes	1.8
Average Swap Price per Unit | $	$ 2.43