Commitments and Contingencies - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) office	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Other Commitments [Line Items]
Number of operating branches | office	19
Number of branches under operating leases | office	5
Number of offices | office	19
Rent expense	$ 410	$ 417
Purchases of premises and equipment	1,507	1,509	$ 9,595
Commitments to Extend Credit
Other Commitments [Line Items]
Other commitment	289,900	291,900
Commitments expire within one year	181,900	66,500
Standby Letters of Credit
Other Commitments [Line Items]
Other commitment	$ 5,700	$ 5,600
Director
Other Commitments [Line Items]
Operating leases, annual increase, percentage	3.00%
Owned Properties
Other Commitments [Line Items]
Number of offices | office	14