Retirement Benefits (Defined Benefit Plan Net Periodic Benefit Cost Combined U.S. and Significant Non-U.S. Plans) (Details) - Pension Benefits - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 5	$ 7	$ 17	$ 18
Interest cost	146	151	434	449
Expected return on plan assets	(222)	(218)	(657)	(645)
Amortization of prior service cost			1	0
Recognized actuarial loss	8	5	23	16
Net benefit credit	(63)	(55)	(182)	(162)
Settlement loss	1	0	1	0
Net benefit credit	(62)	(55)	(181)	(162)
United States
Defined Benefit Plan Disclosure [Line Items]
Interest cost	62	65	187	195
Expected return on plan assets	(76)	(78)	(227)	(233)
Recognized actuarial loss	5	5	15	14
Net benefit credit	(9)	(8)	(25)	(24)
Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	5	7	17	18
Interest cost	84	86	247	254
Expected return on plan assets	(146)	(140)	(430)	(412)
Amortization of prior service cost			1	0
Recognized actuarial loss	3	0	8	2
Net benefit credit	(54)	(47)	(157)	(138)
Settlement loss	1	0	1	0
Net benefit credit	$ (53)	$ (47)	$ (156)	$ (138)