Risk Management (Schedule of Commodity Contracts) (Details) $ in Millions	1 Months Ended
	Jan. 31, 2019 USD ($) MMBbls $ / MBbls	Apr. 30, 2018 USD ($)	Mar. 31, 2019 MMBTU $ / MMBTU	Dec. 31, 2018 Mcfe $ / MBbls $ / MMBTU MBbls
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Cash Received on Hedge | $		$ 1.6
Oil | Swaps - January 2019 to December 2019
Derivative Instruments Related to Oil and Gas Production [Line Items]
Hedged Volume (MBbls) | MBbls				1,022,000
Weighted Average Fixed Price				63.02
Oil | Swaps - January 2020 to December 2020
Derivative Instruments Related to Oil and Gas Production [Line Items]
Hedged Volume (MBbls) | MBbls				732,000
Weighted Average Fixed Price				60.51
Oil | Swaps - February 2019 to December 2019
Derivative Instruments Related to Oil and Gas Production [Line Items]
Weighted Average Fixed Price	62.12
Volume terminated | MMBbls	167
Derivative, Cash Received on Hedge | $	$ 1.5
Natural Gas [Member] | Swaps - January 2019 to December 2019
Derivative Instruments Related to Oil and Gas Production [Line Items]
Hedged Volume (MMBtus) | Mcfe				31,025,000
Weighted Average Fixed Price | $ / MMBTU				2.77
Natural Gas [Member] | Swaps - January 2020 to December 2020 | Subsequent Event [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Hedged Volume (MMBtus) | MMBTU			16,470
Weighted Average Fixed Price | $ / MMBTU			2.70
Natural Gas Liquids [Member] | Swaps - January 2019 to December 2019
Derivative Instruments Related to Oil and Gas Production [Line Items]
Hedged Volume (MBbls) | MBbls				1,095,000
Weighted Average Fixed Price				18.58
Natural Gas Liquids [Member] | Swaps - January 2020 to December 2020
Derivative Instruments Related to Oil and Gas Production [Line Items]
Hedged Volume (MBbls) | MBbls				768,600
Weighted Average Fixed Price				17.68