Quarterly report pursuant to Section 13 or 15(d)

Debt (Details)

v3.21.1
Debt (Details) - USD ($)
$ in Thousands, shares in Millions
3 Months Ended
Dec. 18, 2020
Aug. 20, 2020
Aug. 12, 2020
Jul. 31, 2020
Mar. 31, 2021
Dec. 31, 2020
2.75% Exchangeable Senior Debentures due 2050            
Debt disclosures            
Carrying value         $ 588,064 $ 608,804
Interest rate (as a percent)         2.75% 2.75%
1.25% Exchangeable Senior Debentures due 2050            
Debt disclosures            
Carrying value         $ 811,536 $ 836,971
Interest rate (as a percent)         1.25% 1.25%
1.75% Exchangeable Senior Debentures due 2046            
Debt disclosures            
Carrying value         $ 24,741 $ 26,350
Interest rate (as a percent)         1.75% 1.75%
Exchange of debentures based on share price exceeds on par value           130.00%
Minimum number of days share price exceeds par value           20 days
Number of trading days           30 days
Exchange period           1 year
Senior Credit Facility            
Debt disclosures            
Carrying value         $ 523,000 $ 704,000
SPV | Margin Loan Facility            
Debt disclosures            
Maximum borrowing capacity including incremental facility     $ 2,300,000      
Borrowings $ 1,300,000 $ 100,000   $ 25,000    
Carrying value         2,000,000 $ 2,000,000
Remaining borrowing capacity         $ 300,000  
SPV | Margin Loan Facility | Charter            
Debt disclosures            
Number of common shares pledged as collateral         12.3  
Value of pledged collateral         $ 7,600,000  
SPV | Margin Loan Facility | Three-month LIBOR            
Debt disclosures            
Interest rate basis     three-month LIBOR      
Basis spread on variable rate 1.85%   1.50%