Quarterly report pursuant to Section 13 or 15(d)

DEBT - Schedule of Debt (Details)

v3.21.2
DEBT - Schedule of Debt (Details) - USD ($)
$ in Thousands
Sep. 30, 2021
Mar. 31, 2021
Feb. 28, 2021
Debt Instrument [Line Items]      
Long-term debt $ 531,815 $ 543,493  
Less short-term borrowings and current maturities of long-term debt (13,180) (15,965)  
Total long-term debt 518,635 527,528  
Senior Notes | 6.875% Senior Notes      
Debt Instrument [Line Items]      
Long-term debt $ 391,613 391,550  
Stated interest rate 6.875%   6.875%
Secured Debt | Lombard Debt      
Debt Instrument [Line Items]      
Long-term debt $ 139,968 146,006  
Secured Debt | Airnorth Debt      
Debt Instrument [Line Items]      
Long-term debt 0 5,631  
Secured Debt | Humberside Debt      
Debt Instrument [Line Items]      
Long-term debt $ 234 $ 306