Annual report pursuant to Section 13 and 15(d)

Long-Term Debt (Schedule of Company's Borrowings) (Details)

v3.20.4
Long-Term Debt (Schedule of Company's Borrowings) (Details) - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Debt Instrument [Line Items]    
Long-term debt, gross $ 296,994 $ 340,235
Portion due within one year, net of unamortized discount and issue costs (12,839) (58,854)
Debt discount included in long-term debt (15,460) (19,990)
Debt issuance costs included in long-term debt (4,490) (5,779)
Long-term debt, excluding current maturities 264,205 255,612
Convertible Debt | 3.0% Convertible Senior Notes    
Debt Instrument [Line Items]    
Long-term debt, gross 0 50,041
Debt discount included in long-term debt   (1,600)
Debt issuance costs included in long-term debt   (200)
Convertible Debt | 2.5% Convertible Senior Notes    
Debt Instrument [Line Items]    
Long-term debt, gross 51,585 64,455
Convertible Debt | 3.25% Convertible Senior Notes    
Debt Instrument [Line Items]    
Long-term debt, gross 117,782 117,782
Debt discount included in long-term debt (15,500) (18,400)
Debt issuance costs included in long-term debt (1,400) (1,600)
Line of Credit | SEA-Vista 2019 Credit Facility    
Debt Instrument [Line Items]    
Long-term debt, gross 90,000 100,000
Debt issuance costs included in long-term debt (1,600) (2,100)
Line of Credit | SEACOR Revolving Credit Facility | Revolving Credit Facility    
Debt Instrument [Line Items]    
Long-term debt, gross 20,000 0
Debt issuance costs included in long-term debt (1,400) (1,900)
Notes Payable, Other Payables    
Debt Instrument [Line Items]    
Long-term debt, gross 17,627 7,957
Debt issuance costs included in long-term debt $ (100) $ (100)