The number of periodic payment installments in which the debt is to be repaid.

No definition available.

Name:	ctrm_DebtInstrumentNumberOfPaymentInstallments
Namespace Prefix:	ctrm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
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-Topic 470
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-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-4

+ Details

Name:	us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 55
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482949/835-30-55-8

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Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482925/835-30-45-2

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of the required periodic payments including both interest and principal payments.

+ References

+ Details

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

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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

- References

No definition available.

+ Details

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

- Definition

The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-14

+ Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=ctrm_TermLoanFacilityOstfriesischeVolksbankeGMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=ctrm_RevolvingCredditFacilityOstfriesischeVolksbankeGMember
Namespace Prefix:
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Long-Term Debt, 5 Million Euro Term Loan Facility (Details)			1 Months Ended		6 Months Ended
	Dec. 09, 2024 USD ($)	Dec. 09, 2024 EUR (€)	Jan. 31, 2025 USD ($)	Jan. 31, 2025 EUR (€)	Jun. 30, 2025 USD ($) Installment	Jun. 30, 2025 EUR (€) Installment	Jun. 30, 2024 USD ($)	Jun. 30, 2025 EUR (€)	Dec. 31, 2024 USD ($)	Nov. 20, 2024 USD ($)	Nov. 20, 2024 EUR (€)	Nov. 17, 2023 USD ($)	Nov. 17, 2023 EUR (€)
Debt Instruments [Abstract]
Proceeds from debt					$ 1,577,002		$ 0
5 Million Euro Term Loan [Member]
Debt Instruments [Abstract]
Face amount								€ 5,000,000		$ 5,900,000	€ 5,000,000
Proceeds from debt	$ 4,100,565	€ 3,500,000	$ 1,757,385	€ 1,500,000
Term of loan					5 years	5 years
Number of payment installments \| Installment					20	20
Installment payment					$ 292,898	€ 250,000
Long-term debt					$ 5,272,155				$ 3,657,056
5 Million Euro Term Loan [Member] \| Maximum [Member]
Debt Instruments [Abstract]
Margin on variable rate					2.10%	2.10%
5 Million Euro Term Loan [Member] \| Minimum [Member]
Debt Instruments [Abstract]
Margin on variable rate					1.80%	1.80%
5 Million Euro Revolving Credit Facility [Member]
Debt Instruments [Abstract]
Face amount												$ 5,900,000	€ 5,000,000
Margin on variable rate					1.50%	1.50%