Retirement-Related Benefits - Contributions (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Retirement-Related Benefits
Total plan contributions	$ 245	$ 233
U.S. and Non-U.S. nonpension postretirement benefit plans
Retirement-Related Benefits
Total plan contributions	202	191
Non-U.S. DB plans and multi-employer plans
Retirement-Related Benefits
Total plan contributions	43	42
Pension Plans, Including Multi-employer Plans
Retirement-Related Benefits
Contributions by employer - Noncash	261	249
Nonpension Postretirement Plans | Non-U.S. DB plans
Retirement-Related Benefits
Contributions by employer - Noncash	$ 182	$ 235