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, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Regulatory Asset/Liability for Derivatives	$ (47,416)	$ (42,410)	$ (47,416)	$ (42,410)
Amount Of Gain (Loss) Reclassified from Regulatory Asset/Liability into Income	(16,037)	(16,334)	(46,371)	(59,612)
Natural Gas Future Contracts [Member] | Fuel [Member] | Operating Expense Fuel [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Regulatory Asset/Liability for Derivatives	(53,915)	(40,799)	(53,915)	(40,799)
Amount Of Gain (Loss) Reclassified from Regulatory Asset/Liability into Income	(11,851)	(8,550)	(34,335)	(42,137)
Financial Transmission Rights [Member] | Purchased Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Regulatory Asset/Liability for Derivatives	6,499	(1,611)	6,499	(1,611)
Amount Of Gain (Loss) Reclassified from Regulatory Asset/Liability into Income	$ (4,186)	$ (7,784)	$ (12,036)	$ (17,475)