Condensed Consolidated Income Statements - USD ($)	3 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Income Statement [Abstract]
Net revenue	$ 23,577,000	$ 31,416,000
Cost of goods sold	16,822,000	22,748,000
Gross profit	6,755,000	8,668,000
Operating expenses:
Product engineering and development	758,000	677,000
Selling, general and administrative	2,896,000	3,367,000
Total operating expenses	3,654,000	4,044,000
Operating income	3,101,000	4,624,000
Other income, net:
Interest and dividend income, net of fees	1,177,000	989,000
Realized and unrealized gains (losses) on marketable securities, net	373,000	(455,000)
Total other income, net	1,550,000	534,000
Income before income tax expense	4,651,000	5,158,000
Income tax expense	1,209,000	1,341,000
Net income	$ 3,442,000	$ 3,817,000
Net income per common share - basic	$ 0.23	$ 0.26
Net income per common share - diluted	$ 0.23	$ 0.26