Quarterly report pursuant to Section 13 or 15(d)

Document And Entity Information

v3.8.0.1
Document And Entity Information - shares
3 Months Ended
Mar. 31, 2018
Apr. 23, 2018
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 Mar. 31, 2018  
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus Q1  
Amendment Flag false  
Entity Common Stock, Shares Outstanding   18,174,556
Entity Well-known Seasoned Issuer Yes  
Entity Voluntary Filers No  
Entity Current Reporting Status Yes