v3.26.1
Derivative financial instruments - EDF energy contracts -narrative (Details)
 3 Months Ended
Dec. 31, 2025
USD ($)
item
EDF Energy Contracts [Member]  
Disclosure of information about amounts that affected statement of comprehensive income as result of hedge accounting [line items]  
Number Of Electricity SUpply Agreements | item 2
Hedging instrument, liabilities $ 38,341,000
EDF Energy Contracts [Member] | Minimum  
Disclosure of information about amounts that affected statement of comprehensive income as result of hedge accounting [line items]  
Percentage of Consumption Tolerance Band 80.00%
EDF Energy Contracts [Member] | Maximum  
Disclosure of information about amounts that affected statement of comprehensive income as result of hedge accounting [line items]  
Percentage of Consumption Tolerance Band 120.00%
EDF Energy Contracts [Member] | At fair value  
Disclosure of information about amounts that affected statement of comprehensive income as result of hedge accounting [line items]  
Valuation day-1 difference deferred. $ 898,000
Hedging instrument, liabilities $ 39,239,000
CPI COntract [Member]  
Disclosure of information about amounts that affected statement of comprehensive income as result of hedge accounting [line items]  
Percentage of Forecast Consumption Covered By Electricity Supply Agreement. 70.00%
Retail Contract [Member]  
Disclosure of information about amounts that affected statement of comprehensive income as result of hedge accounting [line items]  
Percentage of Forecast Consumption Covered By Electricity Supply Agreement. 100.00%