XML 89 R74.htm IDEA: XBRL DOCUMENT v3.20.4

Note 2 - Basis of Presentation (Details Textual)	12 Months Ended
	Dec. 31, 2018 USD ($)
Increase in Reverse Repurchase Agreement and Repurchase Agreement Amounts [Member]
Prior Period Reclassification Adjustment	$ 2,461,177

X

- Definition

The amount of a reclassification adjustment made to prior period financial statement amounts.

+ References

No definition available.

+ Details

Name:	us-gaap_PriorPeriodReclassificationAdjustment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Details

Name:	us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis=cohn_IncreaseInReverseRepurchaseAgreementAndRepurchaseAgreementAmountsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: