Equity Capital Structure, Description of Series B Preferred Shares (Details) - Series B Preferred Shares [Member]	12 Months Ended
Dec. 31, 2021 Vote shares
Preferred Shares [Abstract]
Voting power of each preferred share in number of common shares (in shares) \| shares	100,000
Number of votes per share \| Vote	100,000

Number of votes each outstanding preferred share is entitled to vote per share owned on all matters submitted to a vote of shareholders.

No definition available.

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