Investment Securities - Cost basis and fair values of investment securities (Details) - USD ($)	Jun. 30, 2023	Mar. 31, 2023	Jan. 01, 2023	Dec. 31, 2022
Information concerning investments with unrealized gains and losses
Investment securities available for sale, Cost Basis	$ 192,935,000			$ 198,417,000
Investment securities available for sale, Gross Unrealized Gains	21,000			95,000
Investment securities available for sale, Gross Unrealized Losses	(21,603,000)			(19,004,000)
Investment securities available for sale, Allowance for credit losses	(926,000)
Available for Sale, Fair Value	170,427,000			179,508,000
Investment securities held to maturity, Cost Basis	61,832,000			61,878,000
Investment securities held to maturity, Gross Unrealized Gains	3,000			10,000
Investment securities held to maturity, Gross Unrealized Losses	(6,406,000)			(6,696,000)
Investment securities held to maturity, Allowance for credit losses	109,000	$ 83,000	$ 114,000
Investment securities held to maturity, Fair value	55,429,000			55,192,000
U.S. Agency
Information concerning investments with unrealized gains and losses
Investment securities available for sale, Cost Basis	11,655,000			11,797,000
Investment securities available for sale, Gross Unrealized Gains				1,000
Investment securities available for sale, Gross Unrealized Losses	(1,266,000)			(1,265,000)
Available for Sale, Fair Value	10,389,000			10,533,000
Investment securities held to maturity, Cost Basis	2,500,000			2,500,000
Investment securities held to maturity, Gross Unrealized Losses	(444,000)			(432,000)
Investment securities held to maturity, Allowance for credit losses	0
Investment securities held to maturity, Fair value	2,056,000			2,068,000
U.S. Agency mortgage-backed securities
Information concerning investments with unrealized gains and losses
Investment securities available for sale, Cost Basis	99,945,000			102,631,000
Investment securities available for sale, Gross Unrealized Gains	17,000			64,000
Investment securities available for sale, Gross Unrealized Losses	(13,126,000)			(12,710,000)
Available for Sale, Fair Value	86,836,000			89,985,000
Investment securities held to maturity, Cost Basis	19,957,000			18,877,000
Investment securities held to maturity, Gross Unrealized Gains	3,000			8,000
Investment securities held to maturity, Gross Unrealized Losses	(2,317,000)			(2,212,000)
Investment securities held to maturity, Allowance for credit losses	0
Investment securities held to maturity, Fair value	17,643,000			16,673,000
Municipal
Information concerning investments with unrealized gains and losses
Investment securities available for sale, Cost Basis	20,672,000			20,837,000
Investment securities available for sale, Gross Unrealized Losses	(1,678,000)			(1,799,000)
Available for Sale, Fair Value	18,994,000			19,038,000
Investment securities held to maturity, Cost Basis	33,975,000			33,993,000
Investment securities held to maturity, Gross Unrealized Gains				2,000
Investment securities held to maturity, Gross Unrealized Losses	(3,533,000)			(3,880,000)
Investment securities held to maturity, Allowance for credit losses	2,000	3,000	3,000
Investment securities held to maturity, Fair value	30,442,000			30,115,000
Corporate bonds.
Information concerning investments with unrealized gains and losses
Investment securities available for sale, Cost Basis	60,663,000			63,152,000
Investment securities available for sale, Gross Unrealized Gains	4,000			30,000
Investment securities available for sale, Gross Unrealized Losses	(5,533,000)			(3,230,000)
Investment securities available for sale, Allowance for credit losses	(926,000)
Available for Sale, Fair Value	54,208,000			59,952,000
Investment securities held to maturity, Allowance for credit losses			$ 111,000
Corporate bonds and other securities
Information concerning investments with unrealized gains and losses
Investment securities held to maturity, Cost Basis	5,400,000			6,508,000
Investment securities held to maturity, Gross Unrealized Losses	(112,000)			(172,000)
Investment securities held to maturity, Allowance for credit losses	107,000	$ 80,000
Investment securities held to maturity, Fair value	$ 5,288,000			$ 6,336,000

Available for sale of securities and held to maturity securities abstract.

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Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount excluding accrued interest, of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost excluding accrued interest, before allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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

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Amount of accumulated unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity).

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