Investment securities - Summary of Amortized Cost and Fair Value of Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Amortized Cost of Held-to-maturity Securities
Amortized Cost, After five but within ten years, Held to maturity	$ 8,884
Amortized Cost, After ten years, Held to maturity	2,353
Amortized Cost, Held to maturity	11,237
Amortized Cost, Mortgage-backed securities, Held to maturity	79,942
Held-to-maturity, Amortized Cost	91,179	$ 71,213
Fair Value of Held-to-maturity Securities
Fair Value, After five but within ten years, Held to maturity	8,227
Fair Value, After ten years, Held to maturity	2,170
Fair Value, Held to maturity	10,397
Fair Value, Mortgage-backed securities, Held to maturity	66,166
Held to maturity, Fair Value	$ 76,563	$ 70,446

Amount, before allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity).

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