Securities - Schedule of Investments' Gross Unrealized Losses and Fair Value, aggregated by investment category and length of time (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Gain (Loss) on Investments [Line Items]
Less than 12 Months, Fair Value	$ 998
Less than 12 Months, Unrealized Losses	(2)
12 Months or More, Fair Value	0	$ 1,000
12 Months or More, Unrealized Losses	0	(1)
Total, Fair Value	998	1,000
Total, Unrealized Losses	(2)	(1)
U.S. government agencies
Gain (Loss) on Investments [Line Items]
Less than 12 Months, Fair Value	0	0
Less than 12 Months, Unrealized Losses	0	0
12 Months or More, Fair Value	0	0
12 Months or More, Unrealized Losses	0	0
Total, Fair Value	0	0
Total, Unrealized Losses	0	0
Subordinated notes
Gain (Loss) on Investments [Line Items]
Less than 12 Months, Fair Value	998
Less than 12 Months, Unrealized Losses	(2)
12 Months or More, Fair Value	0	1,000
12 Months or More, Unrealized Losses	0	(1)
Total, Fair Value	998	1,000
Total, Unrealized Losses	(2)	(1)
State and municipal obligations
Gain (Loss) on Investments [Line Items]
Less than 12 Months, Fair Value	0	0
Less than 12 Months, Unrealized Losses	0	0
12 Months or More, Fair Value	0	0
12 Months or More, Unrealized Losses	0	0
Total, Fair Value	0	0
Total, Unrealized Losses	$ 0	$ 0