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Retirement Benefits (Narrative) (Details) - USD ($) $ in Millions |  | 1 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Jan. 01, 2017 | Nov. 30, 2019 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 | Nov. 29, 2019
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Assumed health care cost trend rate for Medicare eligibles and non-Medicare eligibles |  |  | 4.91% |  |  |
Future assumed health care cost trend rate |  |  | 4.45% |  |  |
Automatic employer contribution of employee's eligible base pay (as a percent) | 4.00% |  |  |  |  |
401(k) Plan's assets invested in common stock |  |  | $ 677 | $ 742 |  |
U.S. |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Expected employer contributions, next fiscal year |  |  | 31 |  |  |
Cost of defined contribution plans |  |  | $ 161 | 150 | $ 145 |
U.S. | Equities and Equity Alternatives |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Target asset allocation percentage |  |  | 50.00% |  |  |
Actual asset allocation percentage |  |  | 61.00% |  |  |
U.S. | Equities and Equity Alternatives | Minimum |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Target asset allocation percentage |  |  | 46.00% |  |  |
U.S. | Equities and Equity Alternatives | Maximum |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Target asset allocation percentage |  |  | 54.00% |  |  |
U.S. | Fixed Income |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Target asset allocation percentage |  |  | 50.00% |  |  |
Actual asset allocation percentage |  |  | 39.00% |  |  |
U.S. | Fixed Income | Minimum |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Target asset allocation percentage |  |  | 46.00% |  |  |
U.S. | Fixed Income | Maximum |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Target asset allocation percentage |  |  | 54.00% |  |  |
Non-U.S. |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Accumulated benefit obligation for plans with accumulated benefit obligations in excess of plan assets |  |  | $ 935 | 1,600 |  |
Aggregate fair value of plan assets for plans with accumulated benefit obligations in excess of plan assets |  |  | 718 | 1,200 |  |
Projected benefit obligation for plans with projected benefit obligations in excess of plan assets |  |  | 1,000 | 1,700 |  |
Fair value of plan assets for plans with projected benefit obligations in excess of plan assets |  |  | 723 | 1,200 |  |
United Kingdom |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Cost of defined contribution plans |  |  | $ 140 | $ 141 | $ 121 |
United Kingdom | Pension Plan Funded Status Guarantee |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Annual deficit contributions (GBP) |  | $ 450 |  |  |  | $ 541
Annual deficit contributions, period |  | 7 years |  |  |  |
United Kingdom | United Kingdom Pension and Postretirement Benefit Plan, Defined Benefit | Geographic Concentration Risk |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Concentration risk (as a percent) |  |  | 79.00% |  |  |
United Kingdom | Equities and Equity Alternatives |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Target asset allocation percentage |  |  | 14.00% |  |  |
Actual asset allocation percentage |  |  | 16.00% |  |  |
United Kingdom | Equities and Equity Alternatives | Minimum |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Target asset allocation percentage |  |  | 11.00% |  |  |
United Kingdom | Equities and Equity Alternatives | Maximum |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Target asset allocation percentage |  |  | 17.00% |  |  |
United Kingdom | Fixed Income |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Target asset allocation percentage |  |  | 86.00% |  |  |
Actual asset allocation percentage |  |  | 84.00% |  |  |
United Kingdom | Fixed Income | Minimum |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Target asset allocation percentage |  |  | 83.00% |  |  |
United Kingdom | Fixed Income | Maximum |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Target asset allocation percentage |  |  | 89.00% |  |  |
Pension and Postretirement Benefits | U.S. |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Assumed health care cost trend rate for Medicare eligibles and non-Medicare eligibles |  |  | 6.40% |  |  |
Future assumed health care cost trend rate |  |  | 4.00% |  |  |
Cap on employer share of health care trend (as a percent) |  |  | 5.00% |  |  |
Post-retirement Benefits |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Rate of compensation increase (for expense)* |  |  | 0.00% | 0.00% |  |
Post-retirement Benefits | U.S. |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Number of shares held in defined benefit plan (in shares) |  |  | 2,000,000 |  |  |
Change in plan assets (as a percent) |  |  | 7.80% |  |  |
Employer contributions |  |  | $ 4 | $ 3 |  |
Post-retirement Benefits | Non-U.S. |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Rate of compensation increase (for expense)* |  |  | 0.00% | 0.00% |  |
Employer contributions |  |  | $ 2 | $ 3 |  |
Pension Benefits |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Rate of compensation increase (for expense)* |  |  | 3.34% | 1.85% |  |
Pension Benefits | U.S. |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Accumulated benefit obligation for plans with accumulated benefit obligations in excess of plan assets |  |  | $ 4,900 | $ 6,600 |  |
Aggregate fair value of plan assets for plans with accumulated benefit obligations in excess of plan assets |  |  | 4,300 | 5,500 |  |
Projected benefit obligation for plans with projected benefit obligations in excess of plan assets |  |  | 4,900 | 6,600 |  |
Fair value of plan assets for plans with projected benefit obligations in excess of plan assets |  |  | 4,300 | 5,500 |  |
Employer contributions |  |  | $ 30 | $ 35 |  |
Pension Benefits | Non-U.S. |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Rate of compensation increase (for expense)* |  |  | 3.34% | 2.84% |  |
Expected employer contributions, next fiscal year |  |  | $ 76 |  |  |
Employer contributions |  |  | 139 | $ 95 |  |
Pension Benefits | United Kingdom |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |
Expected employer contributions, next fiscal year |  |  | $ 39 |  |  |
Period between legally-prescribed negotiations between the Company and the plans' trustee |  |  | 3 years |  |  |
Employer contributions |  |  | $ 103 |  |  |

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