Fair Value Measurement Fair Values and Carrying Amounts, Significant Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest bearing deposits in banks	$ 8,964	$ 6,565
Investment securities	88,994	88,083
Loans held for sale	32,803	7,442
Deposits
Noninterest bearing	204,555	136,434
Interest bearing	562,970	458,940
Time	142,554	148,653
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	64,477	51,134
Interest bearing deposits in banks	0	0
Investment securities	874	690
Loans held for sale	0	0
Accrued interest receivable	0	0
Deposits
Noninterest bearing	204,555	136,434
Interest bearing	562,970	458,940
Time	0	0
Borrowed funds
Short-term		40,000
Long-term	0	0
Accrued interest payable	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Residential real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Construction real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Commercial real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Consumer
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Municipal
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Interest bearing deposits in banks	9,174	6,671
Investment securities	88,120	87,393
Loans held for sale	34,326	7,587
Accrued interest receivable	440	435
Deposits
Noninterest bearing	0	0
Interest bearing	0	0
Time	143,724	148,542
Borrowed funds
Short-term		0
Long-term	9,962	7,416
Accrued interest payable	107	673
Significant Other Observable Inputs (Level 2) | Residential real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	0	0
Significant Other Observable Inputs (Level 2) | Construction real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	0	0
Significant Other Observable Inputs (Level 2) | Commercial real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	0	0
Significant Other Observable Inputs (Level 2) | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	0	0
Significant Other Observable Inputs (Level 2) | Consumer
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	0	0
Significant Other Observable Inputs (Level 2) | Municipal
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	0	0
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Interest bearing deposits in banks	0	0
Investment securities	0	0
Loans held for sale	0	0
Accrued interest receivable	3,207	2,267
Deposits
Noninterest bearing	0	0
Interest bearing	0	0
Time	0	0
Borrowed funds
Short-term		0
Long-term	0	0
Accrued interest payable	0	0
Significant Unobservable Inputs (Level 3) | Residential real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	186,566	192,955
Significant Unobservable Inputs (Level 3) | Construction real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	49,273	68,381
Significant Unobservable Inputs (Level 3) | Commercial real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	328,895	288,931
Significant Unobservable Inputs (Level 3) | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	111,188	45,872
Significant Unobservable Inputs (Level 3) | Consumer
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	2,788	3,483
Significant Unobservable Inputs (Level 3) | Municipal
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	97,711	67,103
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	64,477	51,134
Interest bearing deposits in banks	8,964	6,565
Investment securities	88,994	88,083
Loans held for sale	32,803	7,442
Accrued interest receivable	3,647	2,702
Nonmarketable equity securities	1,150	2,607
Deposits
Noninterest bearing	204,555	136,434
Interest bearing	562,970	458,940
Time	142,554	148,653
Borrowed funds
Short-term		40,000
Long-term	9,497	7,164
Accrued interest payable	107	673
Carrying Amount | Residential real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	181,207	191,032
Carrying Amount | Construction real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	48,964	68,951
Carrying Amount | Commercial real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	313,061	286,871
Carrying Amount | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	114,296	47,379
Carrying Amount | Consumer
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	2,814	3,545
Carrying Amount | Municipal
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	97,481	67,387
Estimated Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	64,477	51,134
Interest bearing deposits in banks	9,174	6,671
Investment securities	88,994	88,083
Loans held for sale	34,326	7,587
Accrued interest receivable	3,647	2,702
Deposits
Noninterest bearing	204,555	136,434
Interest bearing	562,970	458,940
Time	143,724	148,542
Borrowed funds
Short-term		40,000
Long-term	9,962	7,416
Accrued interest payable	107	673
Estimated Fair Value | Residential real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	186,566	192,955
Estimated Fair Value | Construction real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	49,273	68,381
Estimated Fair Value | Commercial real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	328,895	288,931
Estimated Fair Value | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	111,188	45,872
Estimated Fair Value | Consumer
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	2,788	3,483
Estimated Fair Value | Municipal
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, net	$ 97,711	$ 67,103