Segment Information (Summary Of Operating Revenues And Expenses) (Narrative) (Details) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) segment	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Segment Reporting Information [Line Items]
Segment Reporting Information Operations And Support Expenses	$ 19,863	$ 19,517	$ 58,205	$ 59,467
Number of reportable segments | segment			2
Corporate, non-segment [Member] | Revision of Prior Period, Reclassification, Adjustment [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information Operations And Support Expenses					$ 2,400