v3.26.1
Trade and other receivables (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Jan. 01, 2025
Mar. 31, 2026
Dec. 31, 2024
Dec. 31, 2025
Mar. 31, 2025
Trade and other non-current receivables [abstract]          
Accrued revenue and lease incentive   $ 1.7   $ 2.0  
Payment in advance for property, plant and equipment   23.3   22.2  
Deferred consideration   92.1   89.3  
Withholding tax receivables   21.1   22.3  
Trade and other non-current receivables   138.2   135.8  
Trade and other current receivables [abstract]          
Net trade receivables   110.1   107.5  
Other receivables   28.3   33.4  
Prepaid land rent   3.0   2.1  
Other prepaid expenses   7.8   9.2  
Advance payments   36.9   12.4  
Withholding tax receivables   8.2   10.1  
VAT receivables   8.0   6.7  
Trade and other current receivables   202.3   181.4  
Accrued revenue   $ 55.1     $ 45.2
Cash flow projection period for assessment of withholding tax asset recoverability   5 years      
Vendor loan notes issued on disposal of subsidiaries | Rwanda, Rwanda Francs          
Trade and other current receivables [abstract]          
Notional amount   $ 70.0      
Interest rate   12.00%      
Repayable term   2 years      
Vendor loan notes issued on disposal of subsidiaries | United States of America, Dollars          
Trade and other current receivables [abstract]          
Notional amount   $ 24.5      
Repayable term   3 years      
NIGERIA          
Trade and other current receivables [abstract]          
Withholding tax rate on colocation and telecommunication tower services 2.00%   10.00%    
Maximum          
Trade and other current receivables [abstract]          
Non-current receivable due term   20 years      
Cost          
Trade and other current receivables [abstract]          
Net trade receivables   $ 127.3   119.6  
Allowance for expected credit losses          
Trade and other current receivables [abstract]          
Net trade receivables   $ (17.2)   $ (12.1)