Loans and allowance for loan losses - Effect of Loan Modification on Weighted-average Remaining Life (Detail) |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Commercial and industrial | ||||
| Financing Receivable, Modifications [Line Items] | ||||
| Weighted-average remaining term | 1 year 1 month 6 days | 7 months 6 days | 1 year 8 months 12 days | 9 months 18 days |
| Commercial real estate | ||||
| Financing Receivable, Modifications [Line Items] | ||||
| Weighted-average remaining term | 1 year 4 months 24 days | 9 months 18 days | 1 year 3 months 18 days | 9 months 18 days |
| Residential real estate | ||||
| Financing Receivable, Modifications [Line Items] | ||||
| Weighted-average remaining term | 10 years 7 months 6 days | 9 years 2 months 12 days | 10 years 9 months 18 days | 9 years 8 months 12 days |