Fair Value: Schedule of balances of assets and liabilities, measured at fair value on a non-recurring basis (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
OREO, Fair Value	$ 454,000	$ 483,000	$ 483,000
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans (included in loans receivable, net), recorded investment	19,939,000	10,087,000
OREO, Fair Value	454,000	483,000
Total, Fair Value	20,393,000	10,570,000
Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans (included in loans receivable, net), recorded investment	19,939,000	10,087,000
OREO, Fair Value	454,000	483,000
Total, Fair Value	20,393,000	10,570,000
Impaired loans (included in loans receivable, net), Fair Value	$ 31,000	$ 62,000