Investments: Narrative (Details)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Investments [Abstract]
Investments held-to-maturity, at amortized cost	$ 2,444,000	$ 2,432,000
Collateral pledged as percent of public deposits held	50.00%
Investments pledged as collateral for public deposits	$ 21,000,000	23,100,000
Investments pledged as collateral for FHLB advances	$ 0	$ 0
Number of positions in unrealized loss position	123	51