Annual report pursuant to Section 13 and 15(d)

Quarterly Financial Information (Details)

v3.8.0.1
Quarterly Financial Information (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Quarterly Financial Data [Abstract]                      
Operating Revenues $ 185,515 $ 158,171 $ 115,791 $ 118,414 $ 126,196 $ 109,570 $ 99,647 $ 105,052 $ 577,891 $ 440,465 $ 521,987
Operating Income (Loss) 22,983 15,090 8,993 3,417 (21,950) 5,609 1,802 4,839 50,483 (9,700) 43,289
Net Income (Loss) $ 79,521 $ 10,177 $ (456) $ 16,104 $ (33,877) $ (8,634) $ (23,764) $ (10,276) 81,709 (195,772) (59,850)
Net Income (Loss) attributable to SEACOR Holdings Inc.                 $ 61,643 $ (215,897) $ (68,782)
Basic Earnings (Loss) Per Common Share of SEACOR Holdings Inc.                 $ 3.55 $ (12.76) $ (3.94)
Diluted Earnings (Loss) Per Common Share of SEACOR Holdings Inc.                 $ 3.31 $ (12.76) $ (3.94)