Fair Value of Financial Instruments - Summary (Details) - USD ($)	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Assets:
Cash and due from banks	$ 18,406,000	$ 22,576,000
Federal funds sold and overnight interest-bearing deposits	116,255,000	55,545,000
Certificates of deposit in other banks	10,364,000	10,862,000
Available for sale securities	192,036,000	175,093,000
Loans held for sale	9,041,000	428,000	$ 121,000
Mortgage servicing rights	2,145,000	2,482,000	$ 2,657,000	$ 2,931,000
Accrued interest receivable	7,600,000	6,481,000
Deposits:
Non-interest bearing demand	367,828,000	261,166,000
Savings, interest checking and money market	652,429,000	614,331,000
Operating lease liabilities	2,099,000	2,224,000
Accrued interest payable	901,000	1,136,000
Carrying Amount
Assets:
Cash and due from banks	18,406,000	22,576,000
Federal funds sold and overnight interest-bearing deposits	116,255,000	55,545,000
Certificates of deposit in other banks	10,364,000	10,862,000
Available for sale securities	192,036,000	175,093,000
Other investment securities	6,976,000	5,808,000
Loans, net	1,263,993,000	1,156,320,000
Loans held for sale	9,041,000	428,000
Cash surrender value - life insurance	2,425,000	2,398,000
Accrued interest receivable	7,600,000	6,481,000
Assets, Total	1,627,096,000	1,435,511,000
Deposits:
Non-interest bearing demand	367,828,000	261,166,000
Savings, interest checking and money market	652,429,000	614,331,000
Time deposits	307,376,000	311,024,000
Federal funds purchased and securities sold under agreements to repurchase	42,197,000	27,272,000
Federal Home Loan Bank advances and other borrowings	125,802,000	96,919,000
Subordinated notes	49,486,000	49,486,000
Operating lease liabilities	2,099,000	2,224,000
Accrued interest payable	901,000	1,136,000
Liabilities, Total	1,548,118,000	1,363,558,000
Total Fair Value
Assets:
Cash and due from banks	18,406,000	22,576,000
Federal funds sold and overnight interest-bearing deposits	116,255,000	55,545,000
Certificates of deposit in other banks	10,364,000	10,862,000
Available for sale securities	192,036,000	175,093,000
Other investment securities	6,976,000	5,808,000
Loans, net	1,283,400,000	1,148,339,000
Loans held for sale	9,352,000	435,000
Cash surrender value - life insurance	2,425,000	2,398,000
Accrued interest receivable	7,600,000	6,481,000
Assets, Total	1,646,814,000	1,427,537,000
Deposits:
Non-interest bearing demand	367,828,000	261,166,000
Savings, interest checking and money market	652,429,000	614,331,000
Time deposits	310,395,000	311,489,000
Federal funds purchased and securities sold under agreements to repurchase	42,197,000	27,272,000
Federal Home Loan Bank advances and other borrowings	129,686,000	97,833,000
Subordinated notes	40,187,000	43,640,000
Operating lease liabilities	2,099,000	2,224,000
Accrued interest payable	901,000	1,136,000
Liabilities, Total	1,545,722,000	1,359,091,000
Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash and due from banks	18,406,000	22,576,000
Federal funds sold and overnight interest-bearing deposits	116,255,000	55,545,000
Certificates of deposit in other banks	10,364,000	10,862,000
Available for sale securities	776,000	995,000
Other investment securities	14,000	13,000
Loans, net	0	0
Loans held for sale	0	0
Cash surrender value - life insurance	0	0
Accrued interest receivable	7,600,000	6,481,000
Assets, Total	153,415,000	96,472,000
Deposits:
Non-interest bearing demand	367,828,000	261,166,000
Savings, interest checking and money market	652,429,000	614,331,000
Time deposits	0	0
Federal funds purchased and securities sold under agreements to repurchase	42,197,000	27,272,000
Federal Home Loan Bank advances and other borrowings	0	0
Subordinated notes	0	0
Operating lease liabilities		0
Accrued interest payable	901,000	1,136,000
Liabilities, Total	1,063,355,000	903,905,000
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	191,260,000	174,098,000
Other investment securities	6,962,000	5,795,000
Loans, net	0	0
Loans held for sale	0	0
Cash surrender value - life insurance	2,425,000	2,398,000
Accrued interest receivable	0	0
Assets, Total	200,647,000	182,291,000
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	129,686,000	97,833,000
Subordinated notes	40,187,000	43,640,000
Operating lease liabilities	2,099,000	2,224,000
Accrued interest payable	0	0
Liabilities, Total	171,972,000	143,697,000
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	1,283,400,000	1,148,339,000
Loans held for sale	9,352,000	435,000
Cash surrender value - life insurance	0	0
Accrued interest receivable	0	0
Assets, Total	1,292,752,000	1,148,774,000
Deposits:
Non-interest bearing demand	0	0
Savings, interest checking and money market	0	0
Time deposits	310,395,000	311,489,000
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
Operating lease liabilities		0
Accrued interest payable	0	0
Liabilities, Total	$ 310,395,000	$ 311,489,000