AOCL (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	Dec. 31, 2022
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	$ (1,332)	$ (1,392)	$ (1,343)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(52)	(53)	(53)	$ (54)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	1	1
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(1,280)	(1,339)	$ (1,290)	$ (1,348)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	14	12
Reclassification from AOCI, Current Period, Tax	(4)	(3)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	$ 10	$ 9