Segment Reporting - Segment information (Details)
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2021
USD ($)
Jun. 30, 2020
USD ($)
Jun. 30, 2021
USD ($)
segment
Jun. 30, 2020
USD ($)
Dec. 31, 2020
USD ($)
Segment Reporting Information [Line Items]          
Number of Reportable Segments | segment     2    
Revenues          
Interest income $ 6,972,000 $ 6,193,000 $ 14,003,000 $ 11,877,000  
Gain on sale of loans 2,729,000 2,804,000 6,904,000 4,429,000  
Other revenues 926,000 788,000 1,787,000 1,661,000  
Total revenues 10,627,000 9,785,000 22,694,000 17,967,000  
Expenses          
Provision for (recovery of) loan losses (500,000) 300,000 (500,000) 700,000 $ 950,000
Recovery of provision for loan losses (500,000) 300,000 (500,000) 700,000  
Interest expense 580,000 1,249,000 1,235,000 2,506,000  
Salaries and benefits 3,512,000 2,612,000 6,933,000 5,635,000  
Commissions 890,000 777,000 1,668,000 1,215,000  
Other expenses 1,948,000 1,847,000 4,128,000 3,773,000  
Total operating expenses 6,430,000 6,785,000 13,464,000 13,829,000  
Income before income taxes 4,197,000 3,000,000 9,230,000 4,138,000  
Income tax expense 903,000 665,000 2,039,000 905,000  
Net income 3,294,000 2,335,000 7,191,000 3,233,000  
Total assets 717,932,000 722,646,000 717,932,000 722,646,000 $ 706,236,000
Eliminations [Member]          
Revenues          
Interest income 0 (30,000) (23,000) (45,000)  
Gain on sale of loans 0 0      
Other revenues (45,000) (60,000) (135,000) (116,000)  
Total revenues (45,000) (90,000) (158,000) (161,000)  
Expenses          
Provision for (recovery of) loan losses   0      
Recovery of provision for loan losses 0        
Interest expense 0 (30,000) (23,000) (45,000)  
Salaries and benefits 0 0      
Commissions 0 0      
Other expenses (45,000) (60,000) (135,000) (116,000)  
Total operating expenses (45,000) (90,000) (158,000) (161,000)  
Income before income taxes 0 0      
Income tax expense 0 0      
Net income 0 0      
Total assets (19,427,000) (13,872,000) (19,427,000) (13,872,000)  
Commercial Banking [Member]          
Revenues          
Interest income 6,870,000 6,087,000 13,789,000 11,677,000  
Gain on sale of loans 0 0      
Other revenues 733,000 571,000 1,456,000 1,304,000  
Total revenues 7,603,000 6,658,000 15,245,000 12,981,000  
Expenses          
Provision for (recovery of) loan losses   300,000   700,000  
Recovery of provision for loan losses (500,000)   (500,000)    
Interest expense 580,000 1,249,000 1,235,000 2,506,000  
Salaries and benefits 2,496,000 1,628,000 4,641,000 3,836,000  
Commissions 0 0      
Other expenses 1,791,000 1,605,000 3,635,000 3,313,000  
Total operating expenses 4,367,000 4,782,000 9,011,000 10,355,000  
Income before income taxes 3,236,000 1,876,000 6,234,000 2,626,000  
Income tax expense 701,000 429,000 1,410,000 588,000  
Net income 2,535,000 1,447,000 4,824,000 2,038,000  
Total assets 717,993,000 723,802,000 717,993,000 723,802,000  
Mortagage Banking [Member]          
Revenues          
Interest income 102,000 136,000 237,000 245,000  
Gain on sale of loans 2,729,000 2,804,000 6,904,000 4,429,000  
Other revenues 238,000 277,000 466,000 473,000  
Total revenues 3,069,000 3,217,000 7,607,000 5,147,000  
Expenses          
Provision for (recovery of) loan losses   0      
Recovery of provision for loan losses 0        
Interest expense 0 30,000 23,000 45,000  
Salaries and benefits 1,016,000 984,000 2,292,000 1,799,000  
Commissions 890,000 777,000 1,668,000 1,215,000  
Other expenses 202,000 302,000 628,000 576,000  
Total operating expenses 2,108,000 2,093,000 4,611,000 3,635,000  
Income before income taxes 961,000 1,124,000 2,996,000 1,512,000  
Income tax expense 202,000 236,000 629,000 317,000  
Net income 759,000 888,000 2,367,000 1,195,000  
Total assets $ 19,366,000 $ 12,716,000 $ 19,366,000 $ 12,716,000