XML 99 R76.htm IDEA: XBRL DOCUMENT v3.20.4
Lease obligations - Narrative (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2020
USD ($)
vessel
Dec. 31, 2019
USD ($)
Disclosure of leases [Abstract]    
Expense relating to variable lease payments not included in measurement of lease liabilities $ 91,800 $ 83,700
Expense relating to short-term leases for which recognition exemption has been used 300 500
Potential future lease payments not included in lease liabilities (undiscounted) 53,364 70,600
Lease not yet commenced, amount $ 550,800 $ 6,600
Lease not yet commenced, number of additions | vessel 8  
Lease not yet commenced, term 15 years