Investment in debt securities, Held to Maturity Investment in Debt Securities (Details) - USD ($)	Dec. 31, 2025	Dec. 31, 2024
Investment in Debt Securities [Abstract]
Investment in debt securities	$ 1,304,924	$ 0
Carrying Amount [Abstract]
Due within 1 year	0
Due in 1-5 years	750,000
Due in 5-10 years	0
Carrying amount	750,000
Fair Value [Abstract]
Due within 1 year	0
Due in 1-5 years	760,658
Due in 5-10 years	0
Fair value	760,658
Unrealized Gains [Abstract]
Due within 1 year	0
Due in 1-5 years	10,658
Due in 5-10 years	0
Unrealized gains	10,658
Allowance for credit losses	$ 0

No definition available.

Name:	ctrm_DebtSecuritiesHeldToMaturityUnrealizedGainsAbstract
Namespace Prefix:	ctrm_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Unrealized gains of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

No definition available.