Significant Accounting Policies and Recent Accounting Pronouncements, Revenues Related to Voyage Charter Contracts (Details)	12 Months Ended
Dec. 31, 2021 PerformanceObligation
Revenues Related to Voyage Charter Contracts [Abstract]
Number of performance obligations	1

The number of performance obligations when accounting for revenue from voyage charters under the provisions of ASC 606.

No definition available.

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