v3.19.1
Loans Receivable - Allowance for Loan Losses (Details) - USD ($)
 3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Allowance for Loan and Lease Losses [Roll Forward]                    
Balance at beginning of year       $ 10,033,000       $ 8,597,000 $ 10,033,000 $ 8,597,000
Provision for loan losses $ 500,000 $ 495,000 $ 630,000 515,000 $ 785,000 $ 700,000 $ 620,000 550,000 2,140,000 2,655,000
Charge-Offs                 (1,096,000) (1,652,000)
Recoveries                 231,000 433,000
Balance at end of year 11,308,000       10,033,000       11,308,000 10,033,000
Allowance for Loan Losses Ending Balance Evaluated for Impairment - Individually 262,000       60,000       262,000 60,000
Allowance for Loan Losses Ending Balance Evaluated for Impairment - Collectively 11,046,000       9,973,000       11,046,000 9,973,000
Outstanding Loan Balances Evaluated for Impairment - Individually 4,355,000       8,230,000       4,355,000 8,230,000
Outstanding Loan Balances Evaluated for Impairment - Collectively 997,905,000       880,781,000       997,905,000 880,781,000
Consumer | Other consumer                    
Allowance for Loan and Lease Losses [Roll Forward]                    
Balance at beginning of year       8,000       9,000 8,000 9,000
Provision for loan losses                 1,000 (1,000)
Charge-Offs                 0 0
Recoveries                 0 0
Balance at end of year 9,000       8,000       9,000 8,000
Allowance for Loan Losses Ending Balance Evaluated for Impairment - Individually 0       0       0 0
Allowance for Loan Losses Ending Balance Evaluated for Impairment - Collectively 9,000       8,000       9,000 8,000
Outstanding Loan Balances Evaluated for Impairment - Individually 0       0       0 0
Outstanding Loan Balances Evaluated for Impairment - Collectively 1,202,000       1,053,000       1,202,000 1,053,000
Consumer | Credit card                    
Allowance for Loan and Lease Losses [Roll Forward]                    
Balance at beginning of year       885,000       477,000 885,000 477,000
Provision for loan losses                 963,000 1,217,000
Charge-Offs                 (806,000) (1,124,000)
Recoveries                 42,000 315,000
Balance at end of year 1,084,000       885,000       1,084,000 885,000
Allowance for Loan Losses Ending Balance Evaluated for Impairment - Individually 0       0       0 0
Allowance for Loan Losses Ending Balance Evaluated for Impairment - Collectively 1,084,000       885,000       1,084,000 885,000
Outstanding Loan Balances Evaluated for Impairment - Individually 0       0       0 0
Outstanding Loan Balances Evaluated for Impairment - Collectively 34,673,000       31,507,000       34,673,000 31,507,000
Construction | Real estate:                    
Allowance for Loan and Lease Losses [Roll Forward]                    
Balance at beginning of year       1,646,000       1,591,000 1,646,000 1,591,000
Provision for loan losses                 447,000 55,000
Charge-Offs                 0 0
Recoveries                 0 0
Balance at end of year 2,093,000       1,646,000       2,093,000 1,646,000
Allowance for Loan Losses Ending Balance Evaluated for Impairment - Individually 0       0       0 0
Allowance for Loan Losses Ending Balance Evaluated for Impairment - Collectively 2,093,000       1,646,000       2,093,000 1,646,000
Outstanding Loan Balances Evaluated for Impairment - Individually 0       627,000       0 627,000
Outstanding Loan Balances Evaluated for Impairment - Collectively 157,586,000       144,305,000       157,586,000 144,305,000
Commercial                    
Allowance for Loan and Lease Losses [Roll Forward]                    
Balance at beginning of year       1,497,000       1,174,000 1,497,000 1,174,000
Provision for loan losses                 194,000 345,000
Charge-Offs                 (147,000) (25,000)
Recoveries                 34,000 3,000
Balance at end of year 1,578,000       1,497,000       1,578,000 1,497,000
Allowance for Loan Losses Ending Balance Evaluated for Impairment - Individually 262,000       60,000       262,000 60,000
Allowance for Loan Losses Ending Balance Evaluated for Impairment - Collectively 1,316,000       1,437,000       1,316,000 1,437,000
Outstanding Loan Balances Evaluated for Impairment - Individually 749,000       1,544,000       749,000 1,544,000
Outstanding Loan Balances Evaluated for Impairment - Collectively 121,515,000       107,438,000       121,515,000 107,438,000
Commercial | Real estate:                    
Allowance for Loan and Lease Losses [Roll Forward]                    
Balance at beginning of year       2,860,000       2,682,000 2,860,000 2,682,000
Provision for loan losses                 13,000 375,000
Charge-Offs                 (22,000) (312,000)
Recoveries                 152,000 115,000
Balance at end of year 3,003,000       2,860,000       3,003,000 2,860,000
Allowance for Loan Losses Ending Balance Evaluated for Impairment - Individually 0       0       0 0
Allowance for Loan Losses Ending Balance Evaluated for Impairment - Collectively 3,003,000       2,860,000       3,003,000 2,860,000
Outstanding Loan Balances Evaluated for Impairment - Individually 1,486,000       4,293,000       1,486,000 4,293,000
Outstanding Loan Balances Evaluated for Impairment - Collectively 277,205,000       255,560,000       277,205,000 255,560,000
Residential | Real estate:                    
Allowance for Loan and Lease Losses [Roll Forward]                    
Balance at beginning of year       $ 3,137,000       $ 2,664,000 3,137,000 2,664,000
Provision for loan losses                 522,000 664,000
Charge-Offs                 (121,000) (191,000)
Recoveries                 3,000 0
Balance at end of year 3,541,000       3,137,000       3,541,000 3,137,000
Allowance for Loan Losses Ending Balance Evaluated for Impairment - Individually 0       0       0 0
Allowance for Loan Losses Ending Balance Evaluated for Impairment - Collectively 3,541,000       3,137,000       3,541,000 3,137,000
Outstanding Loan Balances Evaluated for Impairment - Individually 2,120,000       1,766,000       2,120,000 1,766,000
Outstanding Loan Balances Evaluated for Impairment - Collectively $ 405,724,000       $ 340,918,000       $ 405,724,000 $ 340,918,000