Comprehensive Income (Accumulated Other Comprehensive Income, Net Of Tax) (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024	Dec. 31, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning	$ 4,877	$ 4,941	$ 5,259	$ 5,279	$ 4,941	$ 5,279
Net current-period other comprehensive income (loss)	(4)	(5)	(4)	(5)	(9)	(9)
Balance at ending	4,761	4,877	5,137	5,259	4,761	5,137
OPEB [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Deferred tax items	19		26		19	26	$ 23	$ 29
Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning	72	77	91	96	77	96
Net current-period other comprehensive income (loss)	(4)	(5)	(4)	(5)
Balance at ending	68	72	87	91	68	87
Accumulated Other Comprehensive Income [Member] | OPEB [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning		$ 77		$ 96	77	96
Other comprehensive income before reclassifications						1
Amounts reclassified from accumulated other comprehensive loss to net income (loss)					(9)	(10)
Net current-period other comprehensive income (loss)					(9)	(9)
Balance at ending	$ 68		$ 87		$ 68	$ 87