Membership Interests (Schedule Of Changes To Membership Interests) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Balance			$ 12,588,000
Net income	$ 318,000	$ 258,000	741,000	$ 595,000
Capital contributions			318,000	188,000
Distributions			(318,000)	(739,000)
Net effects of cash flow hedges (net of tax)	1,000	1,000	2,000	2,000
Defined benefit pension plans	1,000	1,000	3,000	5,000
Balance	13,334,000		13,334,000
Capital Accounts [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Balance	13,142,000	12,353,000	12,719,000	12,083,000
Net income	318,000	258,000	741,000	595,000
Capital contributions	106,000	62,000	318,000	188,000
Distributions	(106,000)	(546,000)	(318,000)	(739,000)
Balance	13,460,000	12,127,000	13,460,000	12,127,000
Accumulated Other Comprehensive Income (Loss) [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Balance	(128,000)	(146,000)	(131,000)	(151,000)
Net effects of cash flow hedges (net of tax)	1,000	1,000	2,000	2,000
Defined benefit pension plans	1,000	1,000	3,000	5,000
Balance	(126,000)	(144,000)	(126,000)	(144,000)
Membership Interests [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Balance	13,014,000	12,207,000	12,588,000	11,932,000
Net income	318,000	258,000	741,000	595,000
Capital contributions	106,000	62,000	318,000	188,000
Distributions	(106,000)	(546,000)	(318,000)	(739,000)
Net effects of cash flow hedges (net of tax)	1,000	1,000	2,000	2,000
Defined benefit pension plans	1,000	1,000	3,000	5,000
Balance	$ 13,334,000	$ 11,983,000	$ 13,334,000	$ 11,983,000