Employee Benefits - Amounts Recognized in the Consolidated Statements of Financial Position (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Prepaid benefit cost	$ 556	$ 618
Pension Plan | U.K.
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Prepaid benefit cost	505	570
Accrued benefit liability - current	(1)	(1)
Accrued benefit liability - non-current	(26)	(27)
Accumulated other comprehensive loss	1,897	1,909
Net amount recognized	2,375	2,451
Pension Plan | Other
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Prepaid benefit cost	0	1
Accrued benefit liability - current	(4)	(4)
Accrued benefit liability - non-current	(51)	(57)
Accumulated other comprehensive loss	414	431
Net amount recognized	359	371
Pension Plan | U.S.
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Prepaid benefit cost	0	0
Accrued benefit liability - current	(42)	(42)
Accrued benefit liability - non-current	(573)	(658)
Accumulated other comprehensive loss	1,276	1,319
Net amount recognized	$ 661	$ 619