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

The number of tranches in which the debt instrument was drawn down.

+ References

No definition available.

+ Details

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

- Definition

Number of the Company's ship-owning subsidiaries that entered into a senior secured term loan facility.

+ References

No definition available.

+ Details

Name:	ctrm_NumberOfShipOwningSubsidiariesEnteringIntoTermLoanFacility
Namespace Prefix:	ctrm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

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

+ References

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+ Details

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

- Definition

Description of the frequency of periodic payments (monthly, quarterly, annual).

+ References

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+ Details

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

- Definition

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

+ References

+ Details

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

- Definition

Amount of payment greater than the preceding installment payments to be paid at final maturity date of debt.

+ References

No definition available.

+ Details

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

- 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

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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Long-Term Debt, $23.15 million Term Loan Facility (Details)		12 Months Ended
	Nov. 24, 2021 USD ($) Tranche	Dec. 31, 2021 USD ($) Installment	Nov. 22, 2021 USD ($) Subsidiary
$23.15 Million Term Loan Facility [Member]
Long-Term Debt [Abstract]
Number of ship-owning subsidiaries entering into term loan facility \| Subsidiary			2
Face amount		$ 23,150,000	$ 23,150,000
Number of tranches drawn \| Tranche	2
Term of loan		5 years
Number of payment installments \| Installment		60
Frequency of periodic payment		monthly
Balloon installment payable at maturity		$ 8,200,000
$23.15 Million Term Loan Facility [Member] \| Monthly Installments 1 to 18 [Member]
Long-Term Debt [Abstract]
Installment payment		411,500
$23.15 Million Term Loan Facility [Member] \| Monthly Installments 19 to 59 [Member]
Long-Term Debt [Abstract]
Installment payment		$ 183,700
First Tranche [Member]
Long-Term Debt [Abstract]
Face amount	$ 10,150,000
Second Tranche [Member]
Long-Term Debt [Abstract]
Face amount	$ 13,000,000.0