Retirement Plans (Narrative) (Details) retiree in Thousands, shares in Millions, $ in Millions	1 Months Ended	12 Months Ended
	Oct. 31, 2021 USD ($) retiree	Dec. 31, 2022	Dec. 31, 2021 USD ($) shares	Dec. 31, 2020 USD ($) shares	Dec. 31, 2019 USD ($)
Compensation And Retirement Disclosure Line Items
Defined contribution plan, cost recognized			$ 398	$ 379	$ 333
Common stock, shares held in employee trust (shares) | shares			17	19
Percentage of defined contribution plans held from outstanding shares			6.00%	7.00%
Required employer contributions to defined benefit retirement plans during fiscal year			$ 135
Period in which the difference between the actual and expected return on plan assets for qualified plans are recognized in years			5 years
Redemption notice period			90 days
Percentage of pension plan assets held in a single trust for primary domestic government and commercial pension plans			90.00%
U.S.
Compensation And Retirement Disclosure Line Items
Expected decrease in long-term return on assets			1.25%
Pension Benefits
Compensation And Retirement Disclosure Line Items
Expected contribution to defined benefit contribution plans in next fiscal year			$ 40
Buy-out contract annuity contract amount	$ 550
Non-cash settlement charge recognized in buy-out annuity contract	$ 75
Benefit obligation weighed average discount rate			2.84%	2.54%	3.19%
Defined benefit plan, accumulated benefit obligation			$ 17,500	$ 19,400
Net decrease in benefit obligation due to changes in assumptions and future expectations			$ 332
Pension Benefits | U.S.
Compensation And Retirement Disclosure Line Items
Number of retirees and beneficiaries | retiree	21
Expected decrease in long-term return on assets			0.25%
Pension Benefits | U.S. | Forecast | Minimum
Compensation And Retirement Disclosure Line Items
Expected decrease in long-term return on assets		0.00%
Pension Benefits | U.S. | Forecast | Maximum
Compensation And Retirement Disclosure Line Items
Expected decrease in long-term return on assets		3.00%
Other  Post-retirement Benefits
Compensation And Retirement Disclosure Line Items
Benefit obligation weighed average discount rate			2.89%	2.52%
Defined benefit plan, accumulated benefit obligation			$ 840	$ 1,100
Net decrease in benefit obligation due to changes in assumptions and future expectations			$ 85
Other  Post-retirement Benefits | U.S.
Compensation And Retirement Disclosure Line Items
Expected decrease in long-term return on assets			0.25%
Other  Post-retirement Benefits | U.S. | Forecast | Minimum
Compensation And Retirement Disclosure Line Items
Expected decrease in long-term return on assets		0.00%
Other  Post-retirement Benefits | U.S. | Forecast | Maximum
Compensation And Retirement Disclosure Line Items
Expected decrease in long-term return on assets		0.86%