Revision to prior period financial statements (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | |||||||
|---|---|---|---|---|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
Dec. 31, 2024 |
Dec. 31, 2023 |
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| Property, plant and equipment. | $ 1,426.2 | $ 1,426.2 | $ 1,322.2 | [1] | |||||
| Deferred tax liabilities | 94.3 | 94.3 | 88.6 | [1] | |||||
| Retained earnings | (6,875.5) | (6,875.5) | (6,944.0) | [1] | |||||
| Non-current deferred revenue | 94.3 | 94.3 | 45.4 | ||||||
| Current deferred revenue | 32.2 | 32.2 | 19.5 | ||||||
| Revenue | 433.3 | $ 435.4 | 872.9 | $ 853.1 | |||||
| Increase (decrease) in cash and cash equivalents before effect of exchange rate changes | (100.9) | 108.0 | (47.9) | 210.9 | |||||
| Nigeria | |||||||||
| Revenue | $ 260.4 | $ 269.6 | $ 531.7 | $ 497.3 | |||||
| Restatement amount | |||||||||
| Property, plant and equipment. | (30.5) | $ (30.5) | |||||||
| Deferred tax liabilities | (11.9) | (11.9) | |||||||
| Retained earnings | (18.6) | $ (18.6) | |||||||
| Restatement amount | Nigeria | |||||||||
| Non-current deferred revenue | 45.4 | ||||||||
| Current deferred revenue | $ (45.4) | ||||||||
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- Definition The amount of current deferred income including current contract liabilities. [Refer: Deferred income including contract liabilities] Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition The amounts of income taxes payable in future periods in respect of taxable temporary differences. [Refer: Temporary differences [member]] Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The increase (decrease) in cash and cash equivalents before the effect of exchange rate changes on cash and cash equivalents held in foreign currencies. [Refer: Cash and cash equivalents; Effect of exchange rate changes on cash and cash equivalents] Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The amount of non-current deferred income including non-current contract liabilities. [Refer: Deferred income including contract liabilities] Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition The amount of tangible assets that: (a) are held for use in the production or supply of goods or services, for rental to others, or for administrative purposes; and (b) are expected to be used during more than one period. Note that right-of-use assets are not included. [Contrast: Property, plant and equipment including right-of-use assets] Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition A component of equity representing the entity's cumulative undistributed earnings or deficit. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition The income arising in the course of an entity's ordinary activities. Income is increases in assets, or decreases in liabilities, that result in increases in equity, other than those relating to contributions from holders of equity claims. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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