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Securities - Amortized cost and fair value (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) security	Dec. 31, 2019 USD ($) security
Securities available-for-sale:
Amortized Cost	$ 120,215	$ 58,874
Available-for-sale, Gross Unrealized Gains	3,504	366
Available-for-sale, Gross Unrealized Losses	(157)	(384)
Fair value	123,562	58,856
Securities held to maturity:
Held-to-maturity, Amortized Cost	6,510	8,780
Held-to-maturity, Gross Unrealized Gains	347	223
Fair Value	$ 6,857	$ 9,003
Number of securities in unrealized loss positions	14	31
Number of securities deemed other-than-temporarily impaired | security	0	0
Securities pledged as collateral fair value	$ 55,900	$ 19,500
U.S. asset backed securities
Securities available-for-sale:
Amortized Cost	25,303	11,967
Available-for-sale, Gross Unrealized Gains	364
Available-for-sale, Gross Unrealized Losses	(75)	(101)
Fair value	$ 25,592	$ 11,866
Securities held to maturity:
Number of securities in unrealized loss positions | security	8	9
U.S. government agency mortgage-backed securities
Securities available-for-sale:
Amortized Cost	$ 3,854	$ 5,457
Available-for-sale, Gross Unrealized Gains	192	66
Available-for-sale, Gross Unrealized Losses		(26)
Fair value	4,046	$ 5,497
Securities held to maturity:
Number of securities in unrealized loss positions | security		1
U.S. government agency collateralized mortgage obligations
Securities available-for-sale:
Amortized Cost	23,010	$ 35,096
Available-for-sale, Gross Unrealized Gains	916	300
Available-for-sale, Gross Unrealized Losses	(17)	(173)
Fair value	$ 23,909	$ 35,223
Securities held to maturity:
Number of securities in unrealized loss positions | security	1	15
State and municipal securities
Securities available-for-sale:
Amortized Cost	$ 63,848	$ 6,354
Available-for-sale, Gross Unrealized Gains	2,025
Available-for-sale, Gross Unrealized Losses	(63)	(84)
Fair value	65,810	6,270
Securities held to maturity:
Held-to-maturity, Amortized Cost	6,510	8,780
Held-to-maturity, Gross Unrealized Gains	347	223
Fair Value	$ 6,857	$ 9,003
Number of securities in unrealized loss positions | security	3	6
Corporate bonds
Securities available-for-sale:
Amortized Cost	$ 4,200
Available-for-sale, Gross Unrealized Gains	7
Available-for-sale, Gross Unrealized Losses	(2)
Fair value	$ 4,205
Securities held to maturity:
Number of securities in unrealized loss positions | security	2

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