Derivatives Statements of financial performance and financial position (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	$ 885	$ 575
Borrowing Derivative [Member]
Derivative [Line Items]
Derivative, Notional Amount	25,000	25,000
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	885	575
Loan Derivative [Member]
Derivative [Line Items]
Derivative, Notional Amount	33,310	35,503
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	0	0
Other Assets [Member] | Borrowing Derivative [Member]
Derivative [Line Items]
Derivative, Notional Amount	0	0
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	0	0
Other Assets [Member] | Loan Derivative [Member]
Derivative [Line Items]
Derivative, Notional Amount	33,310	24,421
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	(3,934)	(1,781)
Other Assets [Member] | Loan Derivative [Member] | Individually Immaterial Counterparties [Member]
Derivative [Line Items]
Derivative, Notional Amount	0	11,083
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	0	(89)
Other Assets [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Notional Amount	33,310	35,504
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	(3,934)	(1,870)
Other Liabilities [Member] | Borrowing Derivative [Member]
Derivative [Line Items]
Derivative, Notional Amount	25,000	25,000
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	885	575
Other Liabilities [Member] | Loan Derivative [Member]
Derivative [Line Items]
Derivative, Notional Amount	0	11,083
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	0	89
Other Liabilities [Member] | Loan Derivative [Member] | Individually Immaterial Counterparties [Member]
Derivative [Line Items]
Derivative, Notional Amount	33,310	24,421
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	3,934	1,781
Other Liabilities [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Notional Amount	58,310	60,504
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	$ 4,819	$ 2,445