Allowance for Loan and Lease Losses - Allowance for Credit Losses - Reserves (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Financing Receivable Allowance For Credit Losses [Line Items]
Specific	$ 1,108	$ 827	$ 1,429
General	10,345	9,096	8,009
Ending balance	11,453	9,923	9,438	$ 9,750
Unallocated [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
General	12	132	82
Ending balance	12	132	82	30
Real Estate Sector [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Specific	490	493	915
General	6,825	5,142	5,179
Ending balance	7,315	5,635	6,094	5,831
Agricultural Sector [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Specific		1	1
General	235	192	218
Ending balance	235	193	219	256
Commercial and Industrial and Mortgage Warehouse Sector [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Specific	520	219	333
General	2,234	2,466	1,581
Ending balance	2,754	2,685	1,914	2,394
Consumer Loans Sector [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Specific	98	114	180
General	1,039	1,164	949
Ending balance	$ 1,137	$ 1,278	$ 1,129	$ 1,239