Note 1 - Operations and Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($)	3 Months Ended
Mar. 31, 2025	Mar. 31, 2024
Revenue	$ 11,703,000	$ 10,446,000
UNITED STATES
Revenue	8,243,000	7,786,000
Non-US [Member]
Revenue	$ 3,460,000	$ 2,660,000

Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

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+ Details