v3.24.0.1
Introduction and overview of Group's risk management - Internal credit rating (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
USD ($)
customer
Dec. 31, 2022
USD ($)
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables and accrued revenue $ 212,323 $ 211,025
Number of customers 2  
Bottom of range    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Number of customers | customer 2  
Top of range    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Number of customers | customer 5  
Internal Credit Grades, First tier [Member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables and accrued revenue $ 188,621 190,520
Revenue percentage 80.00%  
Internal Credit Grades, Second tier [Member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables and accrued revenue $ 23,702 20,505
Revenue percentage 20.00%  
Gross carrying amount [member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Accrued Revenue $ 86,782 85,131
Trade receivables and accrued revenue 233,528 236,390
Gross carrying amount [member] | Internal Credit Grades, First tier [Member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Accrued Revenue 86,683 84,975
Trade receivables and accrued revenue 197,268 193,117
Gross carrying amount [member] | Internal Credit Grades, Second tier [Member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Accrued Revenue 99 156
Trade receivables and accrued revenue 36,260 43,273
Accumulated impairment [member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables and accrued revenue (21,205) (25,365)
Accumulated impairment [member] | Internal Credit Grades, First tier [Member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables and accrued revenue (8,647) (2,597)
Accumulated impairment [member] | Internal Credit Grades, Second tier [Member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables and accrued revenue (12,558) (22,768)
Not due | Gross carrying amount [member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables 61,571 61,297
Not due | Gross carrying amount [member] | Internal Credit Grades, First tier [Member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables 57,540 58,169
Not due | Gross carrying amount [member] | Internal Credit Grades, Second tier [Member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables 4,031 3,128
030 days | Gross carrying amount [member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables 19,872 24,848
030 days | Gross carrying amount [member] | Internal Credit Grades, First tier [Member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables 17,632 22,581
030 days | Gross carrying amount [member] | Internal Credit Grades, Second tier [Member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables 2,240 2,267
3160 days | Gross carrying amount [member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables 19,604 14,502
3160 days | Gross carrying amount [member] | Internal Credit Grades, First tier [Member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables 15,072 11,233
3160 days | Gross carrying amount [member] | Internal Credit Grades, Second tier [Member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables 4,532 3,269
6190 days | Gross carrying amount [member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables 5,341 8,313
6190 days | Gross carrying amount [member] | Internal Credit Grades, First tier [Member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables 1,128 4,411
6190 days | Gross carrying amount [member] | Internal Credit Grades, Second tier [Member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables 4,213 3,902
Over 90 days | Gross carrying amount [member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables 40,358 42,299
Over 90 days | Gross carrying amount [member] | Internal Credit Grades, First tier [Member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables 19,213 11,748
Over 90 days | Gross carrying amount [member] | Internal Credit Grades, Second tier [Member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Trade receivables $ 21,145 $ 30,551