Derivatives (Disclosure Of Fair Value Of Derivatives) (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Derivative [Line Items]
Derivative Assets	$ 11,435	$ 6,104
Derivative Liabilities	(14,715)	(2,203)
Effect of counterparty netting in derivative assets		(1,890)
Effect of counterparty netting in derivative liabilities		1,890
Derivative Asset	11,435	4,214
Derivative Liability	(14,715)	(313)
Net derivatives as classified in the balance sheets	(3,280)	3,901
Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Assets	11,435	6,104
Derivative Liabilities	(14,715)	(2,203)
Coal Contract \| Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Assets		4,885
Derivative Liabilities	(14,715)	(2,203)
Heating oil - diesel purchases \| Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Assets	$ 11,435	1,219
Derivative Liabilities		$ 0

Fair value of liability associated with financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset.

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