Comprehensive Income (Accumulated Other Comprehensive Income, Net Of Tax) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024	Dec. 31, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning	$ 4,941	$ 5,279
Net current-period other comprehensive income (loss)	(5)	(5)
Balance at ending	4,877	5,259
OPEB [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Deferred tax items	21	27	$ 23	$ 29
Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning	77	96
Net current-period other comprehensive income (loss)	(5)	(5)
Balance at ending	72	91
Accumulated Other Comprehensive Income [Member] | OPEB [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning	77	96
Amounts reclassified from accumulated other comprehensive loss to net income (loss)	(5)	(5)
Net current-period other comprehensive income (loss)	(5)	(5)
Balance at ending	$ 72	$ 91