Derivatives And Risk Management (Schedule Of Derivative Instruments, Volumes Of Natural Gas Production) (Details) - 2015 Fixed Price Swaps [Member] ft³ in Billions	9 Months Ended
Sep. 30, 2015 $ / MMBTU ft³
Derivative [Line Items]
Volume of natural gas production	60
Weighted average swap price \| $ / MMBTU	4.40
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume of natural gas production	30
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Volume of natural gas production	30

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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