Retirement Benefits (Components of the Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension  Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 38	$ 36	$ 31
Interest cost	341	421	487
Expected return on plan assets	(832)	(844)	(863)
Recognized actuarial loss (gain)	206	161	104
Net periodic benefit credit	(247)	(226)	(241)
Curtailment loss	2	0	0
Plan termination	0	1	0
Settlement loss	5	3	7
Total credit	(240)	(222)	(234)
Post-retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	0
Interest cost	2	3	3
Expected return on plan assets	0	0	0
Amortization of prior service	(2)	(2)	(2)
Recognized actuarial loss (gain)	1		(1)
Net periodic benefit credit	2	1
Curtailment loss	0	0	0
Plan termination	0	0	0
Settlement loss	0	0	0
Total credit	2	1	0
U.S. | Pension  Benefits
Defined Benefit Plan Disclosure [Line Items]
Interest cost	184	213	241
Expected return on plan assets	(327)	(345)	(343)
Recognized actuarial loss (gain)	90	72	44
Net periodic benefit credit	(53)	(60)	(58)
U.S. | Post-retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Interest cost	1	1	1
Expected return on plan assets	0	0	0
Recognized actuarial loss (gain)	(1)	0	(1)
Net periodic benefit credit	0	1	0
Non-U.S. | Pension  Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	38	36	31
Interest cost	157	208	246
Expected return on plan assets	(505)	(499)	(520)
Amortization of prior service	0	0	0
Recognized actuarial loss (gain)	116	89	60
Net periodic benefit credit	(194)	(166)	(183)
Curtailment loss	2	0	0
Plan termination	0	1	0
Settlement loss	5	3	7
Total credit	(187)	(162)	(176)
Non-U.S. | Post-retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	0
Interest cost	1	2	2
Expected return on plan assets	0	0	0
Amortization of prior service	(2)	(2)	(2)
Recognized actuarial loss (gain)	2	0	0
Net periodic benefit credit	2	0	0
Curtailment loss	0	0	0
Plan termination	0	0	0
Settlement loss	0	0	0
Total credit	$ 2	$ 0	$ 0