Note 7 - Fair Value Measurements - Schedule of Fair Value Reported on a Recurring Basis (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Equity Securities	$ 2,931,339	$ 2,536,482
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Equity Securities	2,931,339	2,536,482
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US Treasury Securities [Member]
Available-for-Sale Securities
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Domestic Equities [Member]
Equity Securities	1,814,951	1,506,514
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | International Equities [Member]
Equity Securities	570,493	630,494
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other [Member]
Equity Securities	545,895	399,474
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Equity Securities		1,515,234
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US Treasury Securities [Member]
Available-for-Sale Securities		1,515,234
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Domestic Equities [Member]
Equity Securities
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | International Equities [Member]
Equity Securities
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other [Member]
Equity Securities
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Equity Securities
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | US Treasury Securities [Member]
Available-for-Sale Securities
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Domestic Equities [Member]
Equity Securities
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | International Equities [Member]
Equity Securities
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other [Member]
Equity Securities