Securities - Available-for-sale Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Amortized Cost
Due within 1 year	$ 31
Due after 1 year through 5 years	15,662
Due after 5 years through 10 years	164,585
Due after 10 years	390,021
Amortized Cost	570,299	$ 456,514
Estimated Fair Value
Due within 1 year	31
Due after 1 year through 5 years	15,968
Due after 5 years through 10 years	165,720
Due after 10 years	390,782
Fair value	$ 572,501	$ 468,586

Amortized cost 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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Amortized cost 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 second through fifth 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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