Investment securities - Maturity Distribution of Debt Securities Classified as Available-for-Sale (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Investment securities
Within one year	$ 29,255
After one but within five years	205,194
After five but within ten years	83,195
After ten years	92,422
Available for sale securities	410,066
Mortgage-backed and other amortizing securities	103,845
Total	$ 513,911	$ 517,321

Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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