Auditor's remuneration - Summary of Auditor's Remuneration (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Analysis of income and expense [abstract] | |||
| Fees in respect of the audit of the Consolidated and Parent Company Financial Statements, including audit of consolidation returns | $ 42 | $ 45 | $ 39 |
| Other audit fees, principally in respect of audits of accounts of subsidiaries | 19 | 18 | 18 |
| Total audit fees | 61 | 63 | 57 |
| Audit-related fees | 3 | 3 | 3 |
| Fees in respect of other non-audit services | 2 | 3 | 3 |
| Total | $ 66 | $ 69 | $ 63 |