Note 2 - Investments - Mortgage Loans by Loan-to-value Ratio (Details) - USD ($)	Jun. 30, 2022	Dec. 31, 2021
Total commercial mortgages	$ 4,063,276	$ 3,653,142
Debt-to-Value Ratio, 60 to 70 Percent [Member]
Total commercial mortgages	2,547,202	1,960,547
Debt-to-Value Ratio, 40 to 50 Percent [Member]
Total commercial mortgages	336,573	339,335
Debt-to-Value Ratio, 30 to 40 Percent [Member]
Total commercial mortgages	0	195,310
Debt-to-Value Ration, 10 to 30 Percent [Member]
Total commercial mortgages	$ 1,179,501	$ 1,157,950