Employee Benefits - Amounts Recognized in Accumulated Other Comprehensive Loss That Have Not Yet Been Recognized (Details) - Pension Plan - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
U.K.
Amounts recognized in Accumulated other comprehensive loss unrecognized as components of net periodic benefit cost
Net loss	$ 1,854	$ 1,870
Prior service cost (income)	43	39
Net amount recognized	1,897	1,909
Other
Amounts recognized in Accumulated other comprehensive loss unrecognized as components of net periodic benefit cost
Net loss	419	436
Prior service cost (income)	(5)	(5)
Net amount recognized	414	431
U.S.
Amounts recognized in Accumulated other comprehensive loss unrecognized as components of net periodic benefit cost
Net loss	1,276	1,319
Prior service cost (income)	0	0
Net amount recognized	$ 1,276	$ 1,319