Name:	cmre_ContractualObligationOnJvNewbuilds
Namespace Prefix:	cmre_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

This item represents the number of newbuild vessels for which Costamare Ventures has or will contribute 49% of the construction costs and has a contractual commitment as at the period end.

No definition available.

Name:	cmre_NumberOfJvNewbuildVesselsOwnedFourtyNinePercent
Namespace Prefix:	cmre_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

This item represents the assumption used in the calculation of the contracted revenue regarding the redelivery dates used (i.e the earliest possible, the latest possible etc.) in order to be consistent with the previous periods.

No definition available.

Name:	cmre_RedeliveryDates
Namespace Prefix:	cmre_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The number of assumed revenue days used in the calculation of the contracted revenue.

No definition available.

Name:	cmre_RevenueDaysPerAnnum
Namespace Prefix:	cmre_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The remaining terms period (in total months) of the contracted time charter agreements, including the contracted time charter agreements of vessels under construction, from the end of the reporting period.

No definition available.