Note 11 - Other Comprehensive Income (Loss) - Schedule of Other Comprehensive Income and Loss (Details) - USD ($)	3 Months Ended	6 Months Ended
Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2024	Mar. 31, 2023
Unrealized gains (losses)	$ 802,399		$ (260,544)		$ (33,672)	$ (216,597)
Unrealized gains (losses)	(206,537)		67,065		8,668	55,754
Unrealized gains (losses)	595,862		(193,479)		(25,004)	(160,843)
Transfer of realized gains to interest expense	(533,706)		(419,712)		(1,078,889)	(710,491)
Transfer of realized gains to interest expense	137,376		108,034		277,705	182,879
Transfer of realized gains to interest expense	(396,330)		(311,678)		(801,184)	(527,612)
Net interest rate swaps	268,693		(680,256)		(1,112,561)	(927,088)
Net interest rate swaps	(69,161)		175,099		286,373	238,633
Net interest rate swaps	199,532		(505,157)		(826,188)	(688,455)
Amortization of net actuarial losses	16,015		19,703		32,030	39,406
Amortization of net actuarial losses	(4,122)		(5,072)		(8,244)	(10,144)
Amortization of net actuarial losses	11,893		14,631		23,786	29,262
Other comprehensive income	284,708		(660,553)		(1,080,531)	(887,682)
Other comprehensive income	(73,283)		170,027		278,129	228,489
Other comprehensive income	$ 211,425	$ (1,013,827)	$ (490,526)	$ (168,667)	$ (802,402)	$ (659,193)

Amount before tax of other comprehensive income (loss) attributable to parent entity.

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