Retirement Benefits (Summary of the U.S. and Non-U.S. Plan Investments Measured At Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 13,042	$ 19,394
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,535	3,899
Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,509	7,724
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	309	663	$ 774
NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,689	7,108
Total investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14,647	23,293
Total investments | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,535	3,899
Total investments | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,114	11,623
Total investments | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	309	663
Total investments | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,689	7,108
Common/collective trusts
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,038	5,697
Common/collective trusts | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	43	476
Common/collective trusts | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Common/collective trusts | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Common/collective trusts | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,995	5,221
Other investments | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	308	662	773
Corporate obligations
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,402	4,209
Corporate obligations | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,402	4,209
Corporate obligations | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Other investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	329	679
Other investments | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10	11
Other investments | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	11	6
Other investments | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	308	662
Corporate stocks
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	564	2,413
Corporate stocks | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	527	2,368
Corporate stocks | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	36	44
Corporate stocks | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	1	$ 1
Private equity/partnerships
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,433	1,531
Private equity/partnerships | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,433	1,531
Government securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,677	7,379
Government securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15	15
Government securities | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,662	7,364
Real estate
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	261	356
Real estate | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	261	356
Short-term investment funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	612	681
Short-term investment funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	609	681
Company common stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	331	348
Company common stock | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	331	348
Net derivative liabilities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	(1,605)	(3,899)
Net derivative liabilities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Net derivative liabilities | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	(1,605)	(3,899)
Net derivative liabilities | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0