Retirement-Related Benefits - Contributions (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Retirement-Related Benefits
Total plan contributions	$ 163	$ 245
U.S. nonpension postretirement benefit plans
Retirement-Related Benefits
Total plan contributions	134	202
Non-U.S. DB plans and multi-employer plans
Retirement-Related Benefits
Total plan contributions	29	43
Pension Plans, Including Multi-employer Plans
Retirement-Related Benefits
Contributions by employer - Noncash	347	261
Other Postretirement Benefits Plan | U.S. nonpension postretirement benefit plans
Retirement-Related Benefits
Contributions by employer - Noncash	$ 134	$ 182