Note 2 - Summary of Significant Accounting Policies - Revenue From Asset Management Operations (Details) - USD ($)	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021
Asset Management [Member] \| Crossing Bridge Advisor LLC [Member]
Asset management operations revenue	$ 7,271,332	$ 4,287,085
Asset Management [Member] \| Crossing Bridge Advisor LLC [Member] \| CrossingBridge Family of Funds [Member]
Asset management operations revenue	4,283,984	1,557,732
Asset Management [Member] \| Crossing Bridge Advisor LLC [Member] \| Two 1940 Act Regulated Mutual Funds [Member]
Asset management operations revenue	2,740,605	2,729,353
Asset Management [Member] \| Willow Oak Asset Management LLC [Member]
Asset management operations revenue	61,499
Management Fee Revenue [Member] \| Willow Oak Asset Management LLC [Member]
Asset management operations revenue	22,176
Fund Management Services Revenue [Member] \| Crossing Bridge Advisor LLC [Member]
Asset management operations revenue	246,743	$ 0
Fund Management Services Revenue [Member] \| Willow Oak Asset Management LLC [Member]
Asset management operations revenue	38,740
Performance Fee Revenue [Member] \| Willow Oak Asset Management LLC [Member]
Asset management operations revenue	$ 583

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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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+ Details