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Investment securities (Details) - USD ($) $ in Thousands	6 Months Ended
Investment securities (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Jun. 30, 2025	Mar. 31, 2026	Dec. 31, 2025
Debt and Equity Securities, FV-NI [Line Items]
Held-to-maturity, allowance for credit losses	$ 0			$ 0
Allowance for credit loss on available-for-sale debt securities	0			0
Allowance for credit loss on held to maturity debt securities			$ 0	0
Debt securities, available-for-sale, sold		$ 0
Available-for-sale, Amortized Cost	488,750			541,707
Proceeds from sales of investment securities available for sale	32,400
Net gain on securities sold	510
Gross realized losses	0
Investment securities purchased	22,952	$ 28,229
Net loss on securities sold	0
Equity securities without readily determinable fair values	5,000			4,908
Impairment Related to Equity Securities	0
U.S. Treasury securities
Debt and Equity Securities, FV-NI [Line Items]
Available-for-sale, Amortized Cost	19,123			32,125
Mortgage-backed Securities, U.S. Government agencies
Debt and Equity Securities, FV-NI [Line Items]
Available-for-sale, Amortized Cost	20,476			42,801
Federal Home Loan Bank (FHLB)
Debt and Equity Securities, FV-NI [Line Items]
Equity securities without readily determinable fair values	14,300			12,400
State and municipals, Tax-exempt
Debt and Equity Securities, FV-NI [Line Items]
Available-for-sale, Amortized Cost	149,271			$ 132,586
Residential mortgage-backed securities
Debt and Equity Securities, FV-NI [Line Items]
Available-for-sale, Amortized Cost	$ 31,900