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Retirement Benefits - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended			6 Months Ended
	Feb. 28, 2025	Jun. 30, 2026	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2026	Jun. 30, 2025
Compensation and Retirement Disclosure [Line Items]
Portion of pension and OPEB obligation attributed to disclosed plans (as a percent)					98.00%
Defined contribution plan expenses		$ 42	$ 41		$ 83	$ 81
Defined Benefit Plan Purchase of Annuity Contract	$ 423
Pension Plan [Member]
Compensation and Retirement Disclosure [Line Items]
Settlements						82
Pension Plan [Member] \| United States [Member]
Compensation and Retirement Disclosure [Line Items]
Defined benefit pension plans, employer contributions					0
Defined benefit plan, estimated future employer additional contributions, remainder of fiscal year		0			0
Settlements		0	0	$ 82	0	82
Pension Plan [Member] \| United Kingdom [Member]
Compensation and Retirement Disclosure [Line Items]
Defined benefit plan, estimated future employer additional contributions, remainder of fiscal year		1			1
Settlements		0	0		0	3
Pension Plan [Member] \| United Kingdom [Member] \| Maximum [Member]
Compensation and Retirement Disclosure [Line Items]
Defined benefit pension plans, employer contributions					1
Pension Plan [Member] \| Other Foreign Plans [Member]
Compensation and Retirement Disclosure [Line Items]
Defined benefit plan, estimated future employer additional contributions, remainder of fiscal year		1			1
Settlements		$ 2	$ 0		5	$ 0
Pension Plan [Member] \| Other Foreign Plans [Member] \| Maximum [Member]
Compensation and Retirement Disclosure [Line Items]
Defined benefit pension plans, employer contributions					$ 1