Securities Available-for-sale - Available-for-sale securities reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost	$ 125,053	$ 99,089
Unrealized gains	1,347	138
Unrealized losses	(343)	(2,022)
Securities available-for-sale, at fair value	126,057	97,205
U.S. agency securities
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost	8,986	16,052
Unrealized gains	95	32
Unrealized losses	(15)	(197)
Securities available-for-sale, at fair value	9,066	15,887
Corporate securities
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost	10,525	7,074
Unrealized gains	52
Unrealized losses	(7)	(209)
Securities available-for-sale, at fair value	10,570	6,865
Municipal bonds
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost	20,516	14,446
Unrealized gains	604	23
Unrealized losses		(275)
Securities available-for-sale, at fair value	21,120	14,194
Mortgage-backed securities
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost	62,745	45,827
Unrealized gains	405	83
Unrealized losses	(300)	(1,074)
Securities available-for-sale, at fair value	62,850	44,836
U.S. Small Business Administration securities
Debt and Equity Securities, FV-NI [Line Items]
Amortized cost	22,281	15,690
Unrealized gains	191	0
Unrealized losses	(21)	(267)
Securities available-for-sale, at fair value	$ 22,451	$ 15,423