amortized cost, fair value and tax equivalent yield of securities, by maturity (Details) $ in Thousands	9 Months Ended
Sep. 30, 2021 USD ($)
U S Treasury 1 [Member]
Summary of Investment Holdings [Line Items]
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost	$ 10,397
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value	$ 10,302
Receivable with Imputed Interest, Effective Yield (Interest Rate)	1.15%
U S Government Agency Notes 2 [Member]
Summary of Investment Holdings [Line Items]
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost	$ 15,902
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value	$ 15,848
Receivable with Imputed Interest, Effective Yield (Interest Rate)	1.23%
U S Government Agency Notes Total [Member]
Summary of Investment Holdings [Line Items]
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost	$ 26,299
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value	$ 26,150
Receivable with Imputed Interest, Effective Yield (Interest Rate)	1.20%
U S States And Political Subdivisions 2 [Member]
Summary of Investment Holdings [Line Items]
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost	$ 3,594
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value	$ 3,820
Receivable with Imputed Interest, Effective Yield (Interest Rate)	2.80%
U S States And Political Subdivisions 3 [Member]
Summary of Investment Holdings [Line Items]
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost	$ 34,931
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value	$ 35,785
Receivable with Imputed Interest, Effective Yield (Interest Rate)	2.61%
U S States And Political Subdivisions Total [Member]
Summary of Investment Holdings [Line Items]
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost	$ 38,525
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value	$ 39,605
Receivable with Imputed Interest, Effective Yield (Interest Rate)	2.63%
Corporate Debt Securities [Member]
Summary of Investment Holdings [Line Items]
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost	$ 11,000
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value	$ 11,197
Receivable with Imputed Interest, Effective Yield (Interest Rate)	4.61%
Available-for-sale Securities [Member]
Summary of Investment Holdings [Line Items]
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost	$ 173,918
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value	$ 175,568
Receivable with Imputed Interest, Effective Yield (Interest Rate)	2.04%

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.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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