Quarterly report pursuant to Section 13 or 15(d)

Document And Entity Information

v3.8.0.1
Document And Entity Information - shares
9 Months Ended
Sep. 30, 2017
Oct. 27, 2017
Document And Entity Information [Abstract]    
Entity Registrant Name SEACOR HOLDINGS INC /NEW/  
Entity Central Index Key 0000859598  
Current Fiscal Year End Date --12-31  
Entity Filer Category Accelerated Filer  
Document Type 10-Q  
Document Period End Date Sep. 30, 2017  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q3  
Amendment Flag false  
Entity Common Stock, Shares Outstanding   17,859,335
Entity Well-known Seasoned Issuer Yes  
Entity Voluntary Filers No  
Entity Current Reporting Status Yes