Loans (Details Textual)	3 Months Ended								12 Months Ended
	Dec. 31, 2020 USD ($) Customer	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2020 USD ($) Loans Customer	Dec. 31, 2019 USD ($) Loans	Dec. 31, 2018 USD ($) Loans
Financing Receivable Modifications [Line Items]
Total troubled debt restructurings	$ 4,100,000				$ 4,600,000				$ 4,100,000	$ 4,600,000
Specific reserves to customers	436,000				61,000				436,000	61,000
Commitments to lend additional amounts to borrowers classified as troubled debt restructurings	0				0				0	0
Allowance adjustment charge offs									65,000	126,000	$ 66,000
Increase in the allowance for loan losses as a result of the allowance									65,000	126,000	66,000
Provision for loan losses	3,000,000	$ 2,600,000	$ 2,400,000	$ 1,100,000	600,000	$ 550,000	$ 750,000	$ 550,000	9,100,000	2,450,000	3,000,000
Maximum commercial loan and commercial real estate relationships	750,000								750,000
Small Business Administration (SBA), CARES Act, Paycheck Protection Program
Financing Receivable Modifications [Line Items]
Total troubled debt restructurings	$ 199,800,000								$ 199,800,000
Number of business customers facilitated assistance | Customer	1,714								1,714
Payments received from forgiveness of loans									$ 67,600,000
Percentage of payments received from forgiveness of loans									33.80%
Commercial real estate
Financing Receivable Modifications [Line Items]
Specific reserves to customers	$ 0				0				$ 0	0
Provision for loan losses									4,745,000	848,000	650,000
Commercial
Financing Receivable Modifications [Line Items]
Specific reserves to customers	357,000				2,000				357,000	2,000
Provision for loan losses									$ 2,998,000	417,000	112,000
Payment Deferral
Financing Receivable Modifications [Line Items]
Number of months offered, deferrals									3 months
Second Three Month Deferral Payments | Commercial real estate
Financing Receivable Modifications [Line Items]
Total troubled debt restructurings	28,500,000								$ 28,500,000
Second Three Month Deferral Payments | Commercial
Financing Receivable Modifications [Line Items]
Total troubled debt restructurings	4,900,000								4,900,000
Residential real estate loan
Financing Receivable Modifications [Line Items]
Total troubled debt restructurings	12,000				19,000				$ 12,000	$ 19,000	$ 146,000
Troubled debt restructured loans with subsequent payment defaults | Loans | Loans									1	1	2
Provision for loan losses									$ 0	$ 0	$ 0
Loans default payment past due period									30 days
Troubled debt restructurings
Financing Receivable Modifications [Line Items]
Specific reserves to customers	$ 81,000				$ 61,000				$ 81,000	$ 61,000
Contractual Interest Rate Reduction | Minimum
Financing Receivable Modifications [Line Items]
Reduction of the notes stated interest rate									0.24%
Contractual Interest Rate Reduction | Maximum
Financing Receivable Modifications [Line Items]
Reduction of the notes stated interest rate									2.74%
Extended Maturity | Minimum
Financing Receivable Modifications [Line Items]
Maturity period loans									2 months
Extended Maturity | Maximum
Financing Receivable Modifications [Line Items]
Maturity period loans									183 months