Borrowings (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Debt Instrument [Line Items]
Long-term debt outstanding	$ 57,113,000	$ 57,113,000	$ 66,296,000	$ 72,068,000
FHLB Advances
Debt Instrument [Line Items]
Long-term debt outstanding	$ 41,716,000	$ 41,716,000	58,716,000
Weighted average rate percentage	2.31%	2.31%
Loan payable to local bank, 4.5% | Loan payable to local bank
Debt Instrument [Line Items]
Long-term debt outstanding	$ 1,457,000	$ 1,457,000	1,830,000
Interest rate percentage	4.50%	4.50%
Period of fixed interest rate		5 years
Loan payable to local bank, 5.25% | Loan payable to local bank
Debt Instrument [Line Items]
Long-term debt outstanding	$ 240,000	$ 240,000	750,000
Loan payable to local bank, 5.25% | Loan payable to local bank | Wall Street Journal Prime Rate
Debt Instrument [Line Items]
Basis spread on prime rate, percentage		0.25%
Effective rate, percentage	3.00%	3.00%
Loan payable variable rate, FCBI | Unsecured promissory note
Debt Instrument [Line Items]
Long-term debt outstanding	$ 2,700,000	$ 2,700,000	0
Effective rate, percentage	3.25%	3.25%
Trust preferred subordinated debt, NWSB | Trust preferred subordinated debt
Debt Instrument [Line Items]
Long-term debt outstanding	$ 5,000,000	$ 5,000,000	5,000,000
Interest rate percentage	6.39%	6.39%
Trust preferred subordinated debt issued	$ 5,000,000	$ 5,000,000
Trust preferred subordinated debt, FCBI | Trust preferred subordinated debt
Debt Instrument [Line Items]
Long-term debt outstanding	6,000,000	6,000,000	$ 0
Trust preferred subordinated debt issued	$ 6,000,000	$ 6,000,000
Trust preferred subordinated debt, FCBI | Trust preferred subordinated debt | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on prime rate, percentage	1.63%
Effective rate, percentage	1.94338%	1.94338%