Long-Term Debt, $40.75 million Term Loan Facility (Details) - $40.75 Million Term Loan Facility [Member]		12 Months Ended
Jul. 27, 2021 Tranche	Dec. 31, 2021 USD ($) Installment	Jul. 23, 2021 USD ($) Subsidiary
Long-Term Debt [Abstract]
Number of ship-owning subsidiaries entering into term loan facility \| Subsidiary			4
Face amount		$ 40,750,000	$ 40,750,000
Number of tranches drawn \| Tranche	4
Number of payment installments \| Installment		20
Frequency of periodic payment		quarterly
Installment payment		$ 1,154,000
Balloon installment payable at maturity		$ 17,700,000

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

No definition available.

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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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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

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

- Definition

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

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Balance Type:	na
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- 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

- References

No definition available.

+ Details

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