v3.25.4

Note 9 - Fair Value Disclosures (Details Textual) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2025 | Dec. 31, 2024 | Dec. 31, 2023
Other Investment Sold, Gain (Loss), Fair Value | $ (156,783) | $ (62,560) | $ (92,931)
Other Investment Sold, Not yet Purchased, Gain (Loss) | $ 1,118 | $ 29,658 | $ 107,816

X
- Definition Represents fair value of gain (loss) for other investment. + References No definition available. + Details
Name: | cohn_OtherInvestmentSoldGainLossFairValue
Namespace Prefix: | cohn_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Represents realized and unrealized gain (loss) for other investment sold not yet purchased. + References No definition available. + Details
Name: | cohn_OtherInvestmentSoldNotYetPurchasedGainLoss
Namespace Prefix: | cohn_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration