Face amount of financial liability at time of sale and leaseback agreement.

No definition available.

Name:	ctrm_FinancialLiabilityFaceAmount
Namespace Prefix:	ctrm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Purchase price of vessel under a sale leaseback agreement.

+ References

No definition available.

+ Details

Name:	ctrm_SaleLeasebackAgreementPurchasePriceOfVessel
Namespace Prefix:	ctrm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentsAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Weighted average remaining lease term for finance lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 53
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479589/842-20-55-53

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (g)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-4

+ Details

Name:	us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Lease term for sale and leaseback transaction, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 842
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479741/842-40-50-2

+ Details

Name:	us-gaap_SaleLeasebackTransactionLeaseTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=ctrm_MagicThunderMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=ctrm_MagicPerseusMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Long-Term Debt and Financial Liabilities, Sale and Leaseback Agreements (Details) - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 29, 2025	Jul. 11, 2025
M/V Magic Thunder [Member]
Long-Term Debt [Abstract]
Financing amount			$ 14,640,000
Term of charter contract	5 years
Purchase price of vessel	$ 6,295,180
Average remaining lease term	4 years 6 months
Weighted average interest rate	6.23%
M/V Magic Perseus [Member]
Long-Term Debt [Abstract]
Financing amount		$ 15,600,000
Term of charter contract	11 years
Purchase price of vessel	$ 0
Average remaining lease term	4 years 6 months
Weighted average interest rate	6.23%