Retirement Plans (Narrative) (Details) - USD ($) shares in Millions, $ in Millions		12 Months Ended
	Jan. 01, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Compensation And Retirement Disclosure Line Items
Defined contribution plan, cost recognized			$ 379	$ 333	$ 302
Common stock, shares held in employee trust (shares)			19
Percentage of defined contribution plans held from outstanding shares			7.00%	7.00%
Required employer contributions to defined benefit retirement plans during fiscal year			$ 480
Period in which the difference between the actual and expected return on plan assets for qualified plans are recognized in years			5 years
Expected decrease in long-term return on assets	1.00%
Percentage of pension plan assets held in a single trust for primary domestic government and commercial pension plans			90.00%
Redemption notice period			90 days
Forecast
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			$ 360
Benefit obligation weighed average discount rate			2.54%	3.19%	4.28%
Defined benefit plan, accumulated benefit obligation			$ 19,400	$ 17,800
Pension Benefits | Forecast
Compensation And Retirement Disclosure Line Items
Expected decrease in long-term return on assets		0.25%
Other  Post-retirement Benefits
Compensation And Retirement Disclosure Line Items
Benefit obligation weighed average discount rate			2.52%	3.18%
Defined benefit plan, accumulated benefit obligation			$ 1,100	$ 1,000
Other  Post-retirement Benefits | Forecast
Compensation And Retirement Disclosure Line Items
Expected decrease in long-term return on assets		0.25%