Note 16 - Equity - Rollforward of Units Outstanding (Details) - Cohen & Company [Member]	3 Months Ended
Mar. 31, 2026 shares
Issuance of shares (in shares)	367,080
Issuance as equity-based compensation (in shares)	1,011,100
Balance, shares (in shares)	1,378,180

Number of common units of ownership outstanding of a limited liability company (LLC).

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 272
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483014/272-10-45-1

+ Details

Name:	us-gaap_CommonUnitOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Total units issued during the year due to the sale of units. All partners include general, limited and preferred partners.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 5
-Subparagraph (SAB Topic 4.F)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-5

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S45
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480100/505-10-S45-8

+ Details

Name:	us-gaap_PartnersCapitalAccountUnitsSaleOfUnits
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of units issued for unit-based payment arrangement issued by partnership. Partner includes, but is not limited to, general, limited and preferred partners.

+ References

+ Details

Name:	us-gaap_PartnersCapitalAccountUnitsUnitbasedCompensation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	dei_LegalEntityAxis=cohn_CohenCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: