v3.25.4

Note 26 - Earnings (Loss) Per Common Share (Details Textual) | 12 Months Ended
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Dec. 31, 2025
Redeemable Non-controlling Interest Membership Units Not Held Share Ratio | 10

X
- Definition Represents redeemable non-controlling interest membership units not held share ratio. + References No definition available. + Details
Name: | cohn_RedeemableNoncontrollingInterestMembershipUnitsNotHeldShareRatio
Namespace Prefix: | cohn_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration