Pension And OPEB Plans (Schedule Of Pension And OPEB Plan Costs) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Net benefit costs	$ 17,000	$ 24,000
Less amounts deferred principally as property, regulatory asset or regulatory liability	1,000	(5,000)
Total recognized in net periodic pension and OPEB costs and as regulatory assets or other comprehensive income	18,000	19,000
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	8,000	9,000
Interest cost	22,000	21,000
Expected return on assets	(26,000)	(25,000)
Amortization of net loss	8,000	13,000
Net benefit costs	12,000	18,000
OPEB Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1,000	1,000
Interest cost	6,000	6,000
Expected return on assets	(2,000)	(1,000)
Amortization of prior service cost		(4,000)
Amortization of net loss		4,000
Net benefit costs	$ 5,000	$ 6,000