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