Fair Value of Financial Instruments - Summary (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Assets:
Cash and due from banks	$ 15,679	$ 23,687
Federal funds sold and overnight interest-bearing deposits	75,035	18,396
Certificates of deposit in other banks	12,741	12,247
Available for sale securities	218,539	218,205
Mortgage servicing rights	2,875	2,931
Accrued interest receivable	6,160	6,162
Deposits:
Non-interest bearing demand	264,218	262,857
Savings, interest checking and money market	625,522	614,040
Operating lease liabilities	2,347
Accrued interest payable	1,093	1,035
Carrying Amount
Assets:
Cash and due from banks	15,679	23,687
Federal funds sold and overnight interest-bearing deposits	75,035	18,396
Certificates of deposit in other banks	12,741	12,247
Available for sale securities	218,539	218,205
Other investment securities	5,735	5,675
Loans, net	1,142,807	1,134,975
Mortgage servicing rights	2,875	2,931
Cash surrender value - life insurance	2,562	2,542
Accrued interest receivable	6,160	6,162
Assets, Total	1,482,133	1,424,820
Deposits:
Non-interest bearing demand	264,218	262,857
Savings, interest checking and money market	625,522	614,040
Time deposits	360,832	321,571
Federal funds purchased and securities sold under agreements to repurchase	22,097	24,647
Federal Home Loan Bank advances and other borrowings	95,096	95,153
Subordinated notes	49,486	49,486
Accrued interest payable	1,093	1,035
Liabilities, Total	1,418,344	1,368,789
Total Fair Value
Assets:
Cash and due from banks	15,679	23,687
Federal funds sold and overnight interest-bearing deposits	75,035	18,396
Certificates of deposit in other banks	12,741	12,247
Available for sale securities	218,539	218,205
Other investment securities	5,735	5,675
Loans, net	1,117,708	1,115,003
Mortgage servicing rights	2,875	2,931
Cash surrender value - life insurance	2,562	2,542
Accrued interest receivable	6,160	6,162
Assets, Total	1,457,034	1,404,848
Deposits:
Non-interest bearing demand	264,218	262,857
Savings, interest checking and money market	625,522	614,040
Time deposits	359,231	318,949
Federal funds purchased and securities sold under agreements to repurchase	22,097	24,647
Federal Home Loan Bank advances and other borrowings	95,524	94,326
Subordinated notes	44,512	45,749
Accrued interest payable	1,093	1,035
Liabilities, Total	1,412,197	1,361,603
Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash and due from banks	15,679	23,687
Federal funds sold and overnight interest-bearing deposits	75,035	18,396
Certificates of deposit in other banks	12,741	12,247
Available for sale securities	2,655	1,952
Other investment securities	0	0
Loans, net	0	0
Mortgage servicing rights	0	0
Cash surrender value - life insurance	0	0
Accrued interest receivable	6,160	6,162
Assets, Total	112,270	62,444
Deposits:
Non-interest bearing demand	264,218	262,857
Savings, interest checking and money market	625,522	614,040
Time deposits	0	0
Federal funds purchased and securities sold under agreements to repurchase	22,097	24,647
Federal Home Loan Bank advances and other borrowings	0	0
Subordinated notes	0	0
Accrued interest payable	1,093	1,035
Liabilities, Total	912,930	902,579
Other Observable Inputs (Level 2)
Assets:
Cash and due from banks	0	0
Federal funds sold and overnight interest-bearing deposits	0	0
Certificates of deposit in other banks	0	0
Available for sale securities	215,884	216,253
Other investment securities	5,735	5,675
Loans, net	0	0
Mortgage servicing rights	0	0
Cash surrender value - life insurance	2,562	2,542
Accrued interest receivable	0	0
Assets, Total	224,181	224,470
Deposits:
Non-interest bearing demand	0	0
Savings, interest checking and money market	0	0
Time deposits	0	0
Federal funds purchased and securities sold under agreements to repurchase	0	0
Federal Home Loan Bank advances and other borrowings	95,524	94,326
Subordinated notes	44,512	45,749
Accrued interest payable	0	0
Liabilities, Total	140,036	140,075
Significant Unobservable Inputs (Level 3)
Assets:
Cash and due from banks	0	0
Federal funds sold and overnight interest-bearing deposits	0	0
Certificates of deposit in other banks	0	0
Available for sale securities	0	0
Other investment securities	0	0
Loans, net	1,117,708	1,115,003
Mortgage servicing rights	2,875	2,931
Cash surrender value - life insurance	0	0
Accrued interest receivable	0	0
Assets, Total	1,120,583	1,117,934
Deposits:
Non-interest bearing demand	0	0
Savings, interest checking and money market	0	0
Time deposits	359,231	318,949
Federal funds purchased and securities sold under agreements to repurchase	0	0
Federal Home Loan Bank advances and other borrowings	0	0
Subordinated notes	0	0
Accrued interest payable	0	0
Liabilities, Total	$ 359,231	$ 318,949