Name:	ctrm_RelatedPartyTransactionCommissionRate
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A commission charged by a related party in connection with each vessel sale and purchase transaction.

No definition available.

Name:	ctrm_RelatedPartyTransactionCommissionRateOnEachVesselSaleAndPurchaseTransaction
Namespace Prefix:	ctrm_
Data Type:	dtr-types:percentItemType
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Period Type:	duration

Commissions paid to a related party broker on time-charter and voyage-charter arrangements.

No definition available.

Name:	ctrm_RelatedPartyTransactionCommissions
Namespace Prefix:	ctrm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Fixed daily fee charged by a related party to provide a wide range of shipping services such as crew management, technical management, operational employment management, insurance arrangements, provisioning, bunkering, accounting services, general administration and audit support.

No definition available.

Name:	ctrm_RelatedPartyTransactionFixedDailyFee
Namespace Prefix:	ctrm_
Data Type:	srt-types:perUnitItemType
Balance Type:	na
Period Type:	duration

Fees paid to related parties for providing a wide range of shipping services such as crew management, technical management, operational employment management, insurance arrangements, provisioning, bunkering, accounting services, general administration and audit support.

No definition available.

Name:	ctrm_RelatedPartyTransactionManagementFees
Namespace Prefix:	ctrm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Fixed quarterly fee charged by a related party to provide a shipping related administrative services.

No definition available.

Name:	ctrm_RelatedPartyTransactionQuarterlyManagementFee
Namespace Prefix:	ctrm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of commission charged by related party for any sale or purchase of vessels for the Company.

No definition available.

Name:	ctrm_RelatedPartyTransactionSaleAndPurchaseCommission
Namespace Prefix:	ctrm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount for accounts payable to related parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(a))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(k)(1))
-URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

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

Amount of selling, general and administrative expenses resulting from transactions, excluding transactions that are eliminated in consolidated or combined financial statements, with related party.

No definition available.

Name:	us-gaap_RelatedPartyTransactionSellingGeneralAndAdministrativeExpensesFromTransactionsWithRelatedParty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

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Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_IncomeStatementLocationAxis=ctrm_VoyageExpensesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RelatedPartyTransactionAxis=ctrm_ManagementAgreementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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Namespace Prefix:
Data Type:	na
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