Accounts receivable - Age Analysis of Accounts Receivable (Details) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Credit risk | ||
| Customer accounts receivable – billed, net of allowance for doubtful accounts | $ 276 | $ 222 |
| Accounts receivable – unbilled | 194 | 201 |
| Other receivables | 28 | 5 |
| Total | 498 | 428 |
| Less than 30 days past billing date | ||
| Credit risk | ||
| Customer accounts receivable – billed, net of allowance for doubtful accounts | 174 | 154 |
| 30-60 days past billing date | ||
| Credit risk | ||
| Customer accounts receivable – billed, net of allowance for doubtful accounts | 78 | 44 |
| 61-90 days past billing date | ||
| Credit risk | ||
| Customer accounts receivable – billed, net of allowance for doubtful accounts | 11 | 12 |
| More than 90 days past billing date | ||
| Credit risk | ||
| Customer accounts receivable – billed, net of allowance for doubtful accounts | $ 13 | $ 12 |