Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2025	Mar. 31, 2024
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Stockholders' equity attributable to parent, beginning balance		$ 7,940
Stockholders' equity attributable to parent, ending balance		8,133
Foreign currency translation [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Stockholders' equity attributable to parent, beginning balance		(1,020)	$ (816)
Other comprehensive income/(loss) before reclassifications		109	(63)
Loss reclassified from accumulated other comprehensive loss (net of income tax)		0	0
Net current-period other comprehensive income/(loss)		109	(63)
Stockholders' equity attributable to parent, ending balance		(911)	(879)
Derivative instruments [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Stockholders' equity attributable to parent, beginning balance	[1]	7	11
Other comprehensive income/(loss) before reclassifications	[1]	3	0
Loss reclassified from accumulated other comprehensive loss (net of income tax)	[1]	0	0
Net current-period other comprehensive income/(loss)	[1]	3	0
Stockholders' equity attributable to parent, ending balance	[1]	10	11
Defined pension and post-retirement benefit costs [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Stockholders' equity attributable to parent, beginning balance		(2,145)	(2,051)
Other comprehensive income/(loss) before reclassifications		92	0
Loss reclassified from accumulated other comprehensive loss (net of income tax)		19	14
Net current-period other comprehensive income/(loss)		111	14
Stockholders' equity attributable to parent, ending balance		(2,034)	(2,037)
Total [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Stockholders' equity attributable to parent, beginning balance		(3,158)	(2,856)
Other comprehensive income/(loss) before reclassifications		204	(63)
Loss reclassified from accumulated other comprehensive loss (net of income tax)		19	14
Net current-period other comprehensive income/(loss)		223	(49)
Stockholders' equity attributable to parent, ending balance		$ (2,935)	$ (2,905)

[1] Reclassification adjustments from accumulated other comprehensive loss related to derivative instruments are included in Revenue and Salaries and benefits in the accompanying condensed consolidated statements of comprehensive income. See Note 9 — Derivative Financial Instruments for additional details regarding the reclassification adjustments for the derivative settlements.