Retirement-Related Benefits - Cost of Pension Plans (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2020 |
Jun. 30, 2019 |
Jun. 30, 2020 |
Jun. 30, 2019 |
|
| Cost/(Income) of Pension Plans | ||||
| Total defined benefit and contribution pension plans cost recognized in the Consolidated Income Statement | $ 596 | $ 441 | $ 1,179 | $ 878 |
| U.S. | Pension Plans | ||||
| Cost/(Income) of Pension Plans | ||||
| Interest cost | $ 375 | $ 469 | $ 750 | $ 941 |
| Interest cost - income statement location | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense |
| Expected return on plan assets | $ (542) | $ (650) | $ (1,084) | $ (1,300) |
| Expected return on plan assets - income statement location | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense |
| Amortization of prior service costs/(credits) | $ 4 | $ 4 | $ 8 | $ 8 |
| Amortization of prior service costs/(credits) - income statement location | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense |
| Recognized actuarial losses | $ 207 | $ 139 | $ 415 | $ 279 |
| Recognized actuarial losses - income statement location | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense |
| Curtailments and settlements - income statement location | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense |
| Other costs - income statement location | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense |
| Total net periodic pension / nonpension (income)/cost of defined benefit plans | $ 44 | $ (37) | $ 89 | $ (71) |
| Cost of defined contribution plans | 154 | 140 | 309 | 289 |
| Total defined benefit and contribution pension plans cost recognized in the Consolidated Income Statement | 198 | 103 | 398 | 218 |
| Non-U.S. | Pension Plans | ||||
| Cost/(Income) of Pension Plans | ||||
| Service cost | 95 | 93 | 190 | 185 |
| Interest cost | $ 137 | $ 206 | $ 266 | $ 413 |
| Interest cost - income statement location | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense |
| Expected return on plan assets | $ (311) | $ (396) | $ (620) | $ (795) |
| Expected return on plan assets - income statement location | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense |
| Amortization of prior service costs/(credits) | $ (5) | $ (7) | $ (9) | $ (13) |
| Amortization of prior service costs/(credits) - income statement location | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense |
| Recognized actuarial losses | $ 340 | $ 312 | $ 682 | $ 626 |
| Recognized actuarial losses - income statement location | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense |
| Curtailments and settlements | $ 13 | $ 3 | $ 21 | $ 4 |
| Curtailments and settlements - income statement location | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense |
| Multi-employer plans | $ 7 | $ 8 | $ 14 | $ 17 |
| Other costs/(credits) | $ 9 | $ 6 | $ 14 | $ 11 |
| Other costs - income statement location | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense | ibm:OtherIncomeAndExpense |
| Total net periodic pension / nonpension (income)/cost of defined benefit plans | $ 284 | $ 225 | $ 559 | $ 449 |
| Cost of defined contribution plans | 113 | 114 | 223 | 212 |
| Total defined benefit and contribution pension plans cost recognized in the Consolidated Income Statement | $ 397 | $ 339 | $ 782 | $ 661 |