Retirement benefits - Summary of Retirement Benefit Expense (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Defined benefit plans: | |||
| Interest income on plan assets | $ (3,417) | $ (1,732) | $ (1,160) |
| Other | 262 | 246 | (343) |
| Total | 850 | 1,375 | 1,293 |
| Defined contribution plans | 474 | 420 | 403 |
| Total retirement benefit expense | 1,324 | 1,795 | 1,696 |
| Pensions | |||
| Defined benefit plans: | |||
| Current service cost, defined benefit plans | 731 | 1,100 | 1,385 |
| Interest expense, defined benefit plans | 3,072 | 1,584 | 1,223 |
| OPEB | |||
| Defined benefit plans: | |||
| Current service cost, defined benefit plans | 36 | 57 | 60 |
| Interest expense, defined benefit plans | $ 166 | $ 120 | $ 128 |
| X | ||||||||||
- Definition The expense of employee service in the current period arising from defined benefit plans. [Refer: Post-employment benefit expense in profit or loss, defined benefit plans] [Contrast: Increase in net defined benefit liability (asset) resulting from current service cost] Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition The amount of interest expense arising from defined benefit plans. [Refer: Interest expense; Post-employment benefit expense in profit or loss, defined benefit plans] [Contrast: Increase (decrease) in net defined benefit liability (asset) resulting from interest expense (income)] Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition The amount of interest income arising from defined benefit plans. [Refer: Interest income; Post-employment benefit expense in profit or loss, defined benefit plans] [Contrast: Increase (decrease) in net defined benefit liability (asset) resulting from interest expense (income)] Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition The amount of post-employment benefit expense included in profit or loss relating to defined benefit plans. [Refer: Profit (loss); Defined benefit plans [domain]] [Contrast: Increase (decrease) in net defined benefit liability (asset) resulting from expense (income) in profit or loss] Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition The amount of post-employment benefit expense relating to defined contribution plans. Defined contribution plans are post-employment benefit plans under which an entity pays fixed contributions into a separate entity (a fund) and will have no legal or constructive obligation to pay further contributions if the fund does not hold sufficient assets to pay all employee benefits relating to employee service in the current and prior periods. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition The amount of post-employment benefit expense included in profit or loss Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Defined Benefit Plans [Abstract] No definition available.
|
| X | ||||||||||
- Definition Other Employee Expense, Net No definition available.
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|