Borrowed Funds and Mandatorily Redeemable Securities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) note	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Borrowed funds and mandatorily redeemable securities
Total long-term debt and mandatorily redeemable securities	$ 71,251	$ 81,864
Annual maturities of long-term debt
2022	5,290
2023	2,510
2024	11,650
2025	610
2026	10,500
Thereafter	40,690
Mandatorily redeemable securities
Interest expense	1,790	2,140	$ 2,220
Securities subject to mandatory redemption
Borrowed funds and mandatorily redeemable securities
Mandatorily redeemable securities	20,598	20,358
Federal Home Loan Bank borrowings
Borrowed funds and mandatorily redeemable securities
Long-term debt	$ 44,150	55,183
Annual maturities of long-term debt
Number of Federal Home Loan Bank borrowings, fixed rate notes | note	16
Collateral security	$ 55,710
Other long-term debt
Borrowed funds and mandatorily redeemable securities
Long-term debt	$ 6,503	$ 6,323
Minimum | Federal Home Loan Bank borrowings
Borrowed funds and mandatorily redeemable securities
Interest rate on Federal Home Loan Bank borrowings (as a percent)	0.54%
Maximum | Federal Home Loan Bank borrowings
Borrowed funds and mandatorily redeemable securities
Interest rate on Federal Home Loan Bank borrowings (as a percent)	5.04%