2) Investments: Investments Classified by Contractual Maturity Date (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	$ 228,397,623	$ 184,979,644
HeldToMaturitySecuritiesEstimatedFairValue	241,498,409	191,850,749
Collateralized Mortgage Backed Securities
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	9,503,016	9,488,083
HeldToMaturitySecuritiesEstimatedFairValue	9,551,537	9,428,612
Redeemable Preferred Stock
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	623,635	623,635
HeldToMaturitySecuritiesEstimatedFairValue	673,192	$ 637,053
DueIn2017Member
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	20,125,883
HeldToMaturitySecuritiesEstimatedFairValue	20,299,016
DueIn2018Through2021Member
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	69,849,085
HeldToMaturitySecuritiesEstimatedFairValue	70,873,975
DueIn2022Through2026Member
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	49,842,819
HeldToMaturitySecuritiesEstimatedFairValue	52,444,399
DueAfter2026Member
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	78,453,185
HeldToMaturitySecuritiesEstimatedFairValue	$ 87,656,290