Commitments and contingencies - Lease Balances (Details) - USD ($) $ in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Commitments and Contingencies Disclosure [Abstract] | ||
| Operating lease right-of-use assets | $ 22.3 | $ 20.7 |
| Operating lease liabilities | $ 25.4 | $ 24.6 |
| Weighted average lease term (years) | 4 years 4 months 24 days | 4 years 7 months 6 days |
| Weighted average discount rate | 2.90% | 3.20% |
| Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] | Other assets | Other assets |
| Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration] | Other Liabilities | Other Liabilities |
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Present value of lessee's discounted obligation for lease payments from operating lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Indicates line item in statement of financial position that includes operating lease liability. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of lessee's right to use underlying asset under operating lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Indicates line item in statement of financial position that includes operating lease right-of-use asset. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Weighted average discount rate for operating lease calculated at point in time. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|