Segment reporting - Summarized financial information (Details) $ in Millions |
3 Months Ended | 6 Months Ended | ||||||
|---|---|---|---|---|---|---|---|---|
|
Jun. 30, 2026
USD ($)
|
Jun. 30, 2025
USD ($)
|
Jun. 30, 2026
USD ($)
segment
|
Jun. 30, 2025
USD ($)
|
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| Disclosure of operating segments [line items] | ||||||||
| Number of operating segments | segment | 3 | |||||||
| Revenues from external customers | $ 428.6 | $ 388.2 | [1] | $ 844.0 | $ 780.3 | [1] | ||
| Nigeria | ||||||||
| Disclosure of operating segments [line items] | ||||||||
| Revenues from external customers | 298.3 | 260.4 | 583.2 | 531.7 | ||||
| SSA | ||||||||
| Disclosure of operating segments [line items] | ||||||||
| Revenues from external customers | $ 130.3 | $ 127.8 | $ 260.8 | $ 248.6 | ||||
| ||||||||