Note 4 - Investments (Tables)

12 Months Ended

Dec. 31, 2023

Notes Tables

Investment [Table Text Block]

	December 31, 2023				December 31, 2022
			Cost/Amortized				Cost/Amortized
	Fair Value		Cost, Net		Fair Value		Cost, Net
U.S. government and agency securities, held-to-maturity (1)	$	3,086	$	3,122	$	4,242	$	4,314
Investment in limited partnership (2)		1,280		1,280		1,000		1,000
Total investments	$	4,366	$	4,402	$	5,242	$	5,314

	December 31, 2023
			Gross		Gross
	Amortized		Unrealized		Unrealized
	Costs		Gains		Losses			Fair Value
U.S. government and agency securities, held-to-maturity	$	3,122	$	-	$	(36	)	$	3,086

	December 31, 2022
			Gross		Gross
	Amortized		Unrealized		Unrealized
	Costs		Gains		Losses			Fair Value
U.S. government and agency securities, held-to-maturity	$	4,314	$	-	$	(72	)	$	4,242

Investments Classified by Contractual Maturity Date [Table Text Block]

	Amortized		Percent of					Percent
	Cost		Total			Fair Value		of Total
Due in one year or less	$	2,122		68.0	%	$	2,096		67.9	%
Due after one year through five years		1,000		32.0	%		990		32.1	%
Due after five years through ten years		-		-	%		-		-	%
Due after ten years		-		-	%		-		-	%
Total	$	3,122		100.0	%	$	3,086		100.0	%

Fair Value Measurements, Recurring and Nonrecurring [Table Text Block]

	December 31, 2023
							Total		Carrying
	Level 1		Level 2		Level 3		Fair Value		Value
U.S. government and agency securities, held-to-maturity	$	-	$	3,086	$	-	$	3,086	$	3,122

	December 31, 2022
							Total		Carrying
	Level 1		Level 2		Level 3		Fair Value		Value
U.S. government and agency securities, held-to-maturity	$	-	$	4,242	$	-	$	4,242	$	4,314

Investment Income [Table Text Block]

	For the Year Ended
	December 31, 2023		December 31, 2022
Interest on:
Cash equivalents	$	266	$	39
Fixed income securities		194		72
Dividends on investment in HC Series B Stock		1,025		1,025
Change in NAV of investment in limited partnership		280		-
Net investment income	$	1,765	$	1,136