Annual report pursuant to Section 13 and 15(d)

Note 3 - Equipment Acquisitions and Dispositions (Details Textual)

v3.19.1
Note 3 - Equipment Acquisitions and Dispositions (Details Textual)
$ in Millions
12 Months Ended
Sep. 13, 2018
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Payments to Acquire Property, Plant and Equipment and Fair Value Derivative Hedges   $ 52.0 $ 69.4 $ 101.3
Number of Equipment Acquired   8 [1] 11 17
Proceeds from Sale of Property, Plant, and Equipment, Including Deposits   $ 18.6 $ 11.2 $ 41.4
Proceeds from Sale of Property, Plant, and Equipment, Excluding Deposits for Future Vessel Sales   18.5    
Proceeds from Deposits   0.1    
Gain (Loss) on Disposition of Property Plant Equipment, Total   5.9 3.9 3.5
Increase (Decrease) in Contract with Customer, Liability   $ 4.4 $ 0.1 $ 0.5
Number of Equipment Removed from Service   16 [2] 4 9
SEACOR Marlin LLC [Member]        
Equity Method Investment, Ownership, Percent Sold 51.00% 51.00%    
Anchor Handling Towing Supply [Member] | SEACOR 88/888 [Member]        
Number of Equipment Acquired   2    
Crew Transfer Vessels [Member]        
Number of Equipment Acquired   2 [1] 2
Number of Equipment Sold   1    
Number of Equipment Removed from Service   1 [2]
Crew Transfer Vessels [Member] | Windcat Offshore Logistics [Member]        
Number of Equipment Acquired   1    
Supply Vessels [Member]        
Number of Equipment Sold   1    
Number of Equipment Removed from Service   1    
Offshore Support Vessels, Anchor Handling Towing Supply [Member]        
Number of Equipment Acquired   [1] 5 2
Number of Equipment Removed from Service   1 [2]
Tow-supply Vessel [Member]        
Number of Equipment Removed from Service   1    
[1] Excludes two AHTS vessels purchased from Managed Entity Seacor 88 and Seacor 888, and one crew transfer vessel purchased from the Company's joint venture FRS Windcat Offshore Logistics.
[2] Excludes the sale of (i) a 51% interest in one supply vessel held by the joint venture Seacor Marlin LLC, (ii) one crew transfer vessel to the joint venture FRS Windcat Offshore Logistics and (iii) three vessels that were previously removed from service (one FSV, one tow-supply vessel and one supply vessel).