Concentrations of risks - Customer Concentration Risk (Details) - Customer Concentration Risk	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Revenue from Contract with Customer Benchmark | Largest Customer
Concentration Risk [Line Items]
Concentration risk (as a percent)	17.90%	17.60%
Revenue from Contract with Customer Benchmark | Customer, Second Largest
Concentration Risk [Line Items]
Concentration risk (as a percent)	16.70%	16.40%
Revenue from Contract with Customer Benchmark | Customer, Third Largest
Concentration Risk [Line Items]
Concentration risk (as a percent)		10.40%
Accounts Receivable | Largest Customer
Concentration Risk [Line Items]
Concentration risk (as a percent)	29.40%	27.20%
Accounts Receivable | Customer, Second Largest
Concentration Risk [Line Items]
Concentration risk (as a percent)	11.40%	19.00%
Accounts Receivable | Customer, Third Largest
Concentration Risk [Line Items]
Concentration risk (as a percent)		12.00%
Accounts Receivable | Customer, Fourth Largest
Concentration Risk [Line Items]
Concentration risk (as a percent)		11.10%