Commitments and Contingent Liabilities - Unused and Available Credit Balances of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Loss Contingencies [Line Items]
Total Commitments	$ 247,463	$ 240,104
Standby Letters of Credit
Loss Contingencies [Line Items]
Total Commitments	80,369	42,041
Performance Letters of Credit
Loss Contingencies [Line Items]
Total Commitments	2,329	2,521
Construction Mortgages
Loss Contingencies [Line Items]
Total Commitments	62,167	59,689
Personal Lines of Credit
Loss Contingencies [Line Items]
Total Commitments	6,897	6,456
Overdraft Protection Lines
Loss Contingencies [Line Items]
Total Commitments	6,407	6,415
Home Equity Lines of Credit
Loss Contingencies [Line Items]
Total Commitments	20,609	20,560
Commercial Lines of Credit
Loss Contingencies [Line Items]
Total Commitments	$ 68,685	$ 102,422