Note 3 - Fair Value Disclosures - Assets Measured at Fair Value on Recurring Basis (Details) - USD ($)	Dec. 31, 2023	Sep. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale	$ 110,955,697	$ 110,955,697	$ 93,388,971
Equity securities	15,087,917		23,211,512
Total marketable investments measured at fair value	126,043,614		116,600,483
Fair Value, Inputs, Level 1 [Member]
Debt Securities, Available-for-Sale	1,289,774		1,252,960
Equity securities	12,191,621		20,438,907
Total marketable investments measured at fair value	13,481,395		21,691,867
Fair Value, Inputs, Level 2 [Member]
Debt Securities, Available-for-Sale	109,665,923		92,136,011
Equity securities	2,896,296		2,772,605
Total marketable investments measured at fair value	112,562,219		94,908,616
US Treasury Securities [Member]
Debt Securities, Available-for-Sale	1,289,774	1,289,774	1,252,960
US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Debt Securities, Available-for-Sale	1,289,774		1,252,960
MBS,ABS,CMBS [Member]
Debt Securities, Available-for-Sale	47,020,328	47,020,328	38,803,341
MBS,ABS,CMBS [Member] | Fair Value, Inputs, Level 2 [Member]
Debt Securities, Available-for-Sale	47,020,328		38,803,341
Corporate Debt Securities [Member]
Debt Securities, Available-for-Sale	42,981,718	42,981,718	35,602,055
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Debt Securities, Available-for-Sale	42,981,718		35,602,055
US States and Political Subdivisions Debt Securities [Member]
Debt Securities, Available-for-Sale	19,493,317	19,493,317	17,541,694
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Debt Securities, Available-for-Sale	19,493,317		17,541,694
Redeemable Preferred Stock [Member]
Debt Securities, Available-for-Sale	170,560	$ 170,560	188,921
Redeemable Preferred Stock [Member] | Fair Value, Inputs, Level 2 [Member]
Debt Securities, Available-for-Sale	170,560		188,921
Common Stock [Member]
Equity securities	12,191,621		20,438,907
Common Stock [Member] | Fair Value, Inputs, Level 1 [Member]
Equity securities	12,191,621		20,438,907
Common Stock [Member] | Fair Value, Inputs, Level 2 [Member]
Equity securities	0
Preferred Stock [Member]
Equity securities	2,896,296		2,772,605
Preferred Stock [Member] | Fair Value, Inputs, Level 2 [Member]
Equity securities	$ 2,896,296		$ 2,772,605