Subsequent Events (Details) - Subsequent Event [Member] $ in Thousands	Jan. 12, 2022 USD ($) Subsidiary Tranches	Jan. 04, 2022 USD ($)
$55.0 Million Deutsche Bank Facility [Member]
Debt Financings [Abstract]
Face amount	$ 55,000
Number of ship-owning subsidiaries entering into term loan facility \| Subsidiary	5
Term of loan	5 years
Trailing period to maintain EBITDA to net interest expense ratio	12 months
Number of tranches drawn \| Tranches	5
Magic Callisto [Member]
Vessel Acquisitions [Abstract]
Purchase price of acquired vessel		$ 23,550

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

No definition available.

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Balance Type:	na
Period Type:	duration

- Definition

Trailing period to maintain earnings before interest, taxes, depreciation, and amortization (EBITDA) to net interest expense ratio above a certain level in the debt agreement, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Namespace Prefix:	ctrm_
Data Type:	xbrli:durationItemType
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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+ Details

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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

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- References

No definition available.

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Period Type:	duration

- Definition

Amount of acquisition of long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

No definition available.

+ Details

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

- References

No definition available.

+ Details

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- Details

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- Details

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- Details

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