2) Investments: Investments Classified by Contractual Maturity Date (Details)	Dec. 31, 2018 USD ($)
Held-to-Maturity Amortized Cost	$ 232,078,723
Held-to-Maturity Estimated Fair Value	234,750,858
Collateralized Mortgage Backed Securities
Held-to-Maturity Amortized Cost	15,358,746
Held-to-Maturity Estimated Fair Value	15,277,280
Redeemable Preferred Stock
Held-to-Maturity Amortized Cost	103,197
Held-to-Maturity Estimated Fair Value	99,975
Due in 2017
Held-to-Maturity Amortized Cost	17,363,658
Held-to-Maturity Estimated Fair Value	17,513,419
Due in 2018 Through 2021
Held-to-Maturity Amortized Cost	66,215,222
Held-to-Maturity Estimated Fair Value	66,479,844
Due in 2022 Through 2026
Held-to-Maturity Amortized Cost	66,450,299
Held-to-Maturity Estimated Fair Value	65,793,696
Due After 2026
Held-to-Maturity Amortized Cost	66,587,601
Held-to-Maturity Estimated Fair Value	$ 69,586,644