Derivatives And Hedging (Schedule Of Derivative Instruments On The Statement Of Revenues, Expenses, And Patronage Capital) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Regulatory Asset/Liability for Derivatives	$ 8,715	$ (47,416)	$ 8,715	$ (47,416)
Amount Of Gain (Loss) Reclassified from Regulatory Asset/Liability into Income	2,135	(16,037)	1,407	(46,371)
Natural Gas Future Contracts [Member] \| Fuel [Member] \| Derivative Instrument Fuel Regulatory Asset Liability [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Regulatory Asset/Liability for Derivatives	549	(53,915)	549	(53,915)
Natural Gas Future Contracts [Member] \| Fuel [Member] \| Derivative Instrument Fuel [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount Of Gain (Loss) Reclassified from Regulatory Asset/Liability into Income	7,313	(11,851)	1,428	(34,335)
Financial Transmission Rights [Member] \| Purchased Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount Of Gain (Loss) Reclassified from Regulatory Asset/Liability into Income	(5,178)	(4,186)	(21)	(12,036)
Financial Transmission Rights [Member] \| Purchased Power [Member] \| Derivative Instrument Purchased Power Regulatory Asset Liability [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Regulatory Asset/Liability for Derivatives	$ 8,166	$ 6,499	$ 8,166	$ 6,499