Note 2 - Investments - Amortized Cost and Fair Value of Available-for-sale and Held-to-maturity Investments (Details) - USD ($)	Mar. 31, 2025	Dec. 31, 2024
Cost or Amortized Cost	$ 82,556,371	$ 83,785,307
Debt securities, gross unrealized gains	958,834	856,381
Debt Securities, Gross Unrealized Losses	(4,636,516)	(5,063,509)
Debt securities, fair value	78,878,689	79,578,179
US Treasury Securities [Member]
Cost or Amortized Cost	801,639	799,543
Debt securities, gross unrealized gains	0	0
Debt Securities, Gross Unrealized Losses	(70,870)	(88,166)
Debt securities, fair value	730,769	711,377
Corporate Debt Securities [Member]
Cost or Amortized Cost	22,353,128	24,370,244
Debt securities, gross unrealized gains	148,954	111,868
Debt Securities, Gross Unrealized Losses	(2,781,649)	(2,990,292)
Debt securities, fair value	19,720,433	21,491,820
US States and Political Subdivisions Debt Securities [Member]
Cost or Amortized Cost	5,393,259	5,416,888
Debt securities, gross unrealized gains	11	0
Debt Securities, Gross Unrealized Losses	(587,431)	(675,739)
Debt securities, fair value	4,805,839	4,741,149
Redeemable Preferred Stock [Member]
Cost or Amortized Cost	2,563,173	2,562,893
Debt securities, gross unrealized gains	14	36
Debt Securities, Gross Unrealized Losses	(168,153)	(151,695)
Debt securities, fair value	2,395,034	2,411,234
Term Loans [Member]
Cost or Amortized Cost	12,148,679	12,971,452
Debt securities, gross unrealized gains	40,109	28,936
Debt Securities, Gross Unrealized Losses	(210,723)	(212,084)
Debt securities, fair value	11,978,065	12,788,304
Collateralized Mortgage-Backed Securities [Member]
Cost or Amortized Cost	39,296,493	37,664,287
Debt securities, gross unrealized gains	769,746	715,541
Debt Securities, Gross Unrealized Losses	(817,690)	(945,533)
Debt securities, fair value	$ 39,248,549	$ 37,434,295