Credit-related arrangements, repurchase agreements and commitments - Commitments (Details) |
Dec. 31, 2025
USD ($)
custodian
|
Dec. 31, 2024
USD ($)
|
|---|---|---|
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | ||
| Purchase obligation | $ 50,089,000 | $ 20,300,000 |
| Number of custodians | custodian | 1 | |
| Commitments to extend credit | $ 577,370,000 | 475,289,000 |
| Documentary and commercial letters of credit | 859,000 | 1,576,000 |
| Total unfunded commitments to extend credit | 578,229,000 | 476,865,000 |
| Allowance for credit losses | (131,000) | (90,000) |
| Custodian | ||
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | ||
| Commitments to extend credit | $ 200,000,000 | |
| Right to set-off against securities held, percent of utilized facility | 110.00% | |
| Custodian | Standby Letters of Credit | ||
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | ||
| Commitments to extend credit | $ 125,000,000.0 | $ 138,400,000 |