Derivative Contracts Schedule Of Commodity Derivative Contracts (Details) MMBTU in Millions	3 Months Ended
	Mar. 31, 2017 USD ($) MMBTU $ / MMBTU
Oil Basis Swaps [Member] | Production [Member] | Year 2017 [Member] | NYMEX WTI less Argus WTI Midland [Member]
Derivative [Line Items]
Derivative Volumes	3.2
Weighted-Average Differential | $ / MMBTU	(0.66)
Oil Basis Swaps [Member] | Production [Member] | Year 2018 [Member] | NYMEX WTI less Argus WTI Midland [Member]
Derivative [Line Items]
Derivative Volumes	3.7
Weighted-Average Differential | $ / MMBTU	(1.01)
Gas Swaps [Member] | Production [Member] | Year 2017 [Member] | NYMEX HH [Member]
Derivative [Line Items]
Derivative Volumes	74.3
Average Swap Price per Unit | $	$ 2.87
Gas Swaps [Member] | Production [Member] | Year 2017 [Member] | IFNPCR [Member]
Derivative [Line Items]
Derivative Volumes	24.8
Average Swap Price per Unit | $	$ 2.51
Gas Swaps [Member] | Production [Member] | Year 2018 [Member] | NYMEX HH [Member]
Derivative [Line Items]
Derivative Volumes	87.6
Average Swap Price per Unit | $	$ 2.98
Gas Swaps [Member] | Storage [Member] | Year 2017 [Member] | IFNPCR [Member]
Derivative [Line Items]
Derivative Volumes	2.2
Average Swap Price per Unit | $	$ 2.71
Oil Swaps [Member] | Production [Member] | Year 2017 [Member] | NYMEX WTI [Member]
Derivative [Line Items]
Derivative Volumes	10.2
Average Swap Price per Unit | $	$ 51.39
Oil Swaps [Member] | Production [Member] | Year 2018 [Member] | NYMEX WTI [Member]
Derivative [Line Items]
Derivative Volumes	9.1
Average Swap Price per Unit | $	$ 53.61
Gas Collars [Member] | Production [Member] | Year 2017 [Member] | NYMEX HH [Member]
Derivative [Line Items]
Derivative Volumes	8.3
Derivative Average Price Floor | $	$ 2.50
Derivative Average Price Ceiling | $	$ 3.50
Gas Basis Swaps [Member] | Production [Member] | Year 2017 [Member] | NYMEX HH LESS IFNPCR [Member]
Derivative [Line Items]
Derivative Volumes	38.5
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)