Quarterly report pursuant to Section 13 or 15(d)

Debt - Summary of Debt (Details)

v3.21.2
Debt - Summary of Debt (Details) - USD ($)
$ in Thousands
Sep. 30, 2021
Dec. 31, 2020
Debt Instrument [Line Items]    
Outstanding principal $ 3,946,470  
Deferred financing costs (1,437) $ (2,017)
Total 4,041,652 4,816,233
Debt classified as current (34,797) (31,026)
Total long-term debt 4,006,855 4,785,207
2.75% Exchangeable Senior Debentures due 2050    
Debt Instrument [Line Items]    
Outstanding principal 575,000  
Carrying value $ 607,976 $ 608,804
Interest rate (as a percent) 2.75% 2.75%
1.25% Exchangeable Senior Debentures due 2050    
Debt Instrument [Line Items]    
Outstanding principal $ 825,000  
Carrying value $ 840,378 $ 836,971
Interest rate (as a percent) 1.25% 1.25%
1.75% Exchangeable Senior Debentures due 2046    
Debt Instrument [Line Items]    
Outstanding principal $ 14,536  
Carrying value $ 30,105 $ 26,350
Interest rate (as a percent) 1.75% 1.75%
Senior notes    
Debt Instrument [Line Items]    
Outstanding principal $ 600,000  
Carrying value 632,696 $ 635,683
Line of credit    
Debt Instrument [Line Items]    
Outstanding principal 426,000  
Carrying value 426,000 704,000
Wells Fargo note payable    
Debt Instrument [Line Items]    
Outstanding principal 5,934  
Carrying value 5,934 6,442
SPV | Margin Loan Facility    
Debt Instrument [Line Items]    
Outstanding principal 1,500,000  
Carrying value $ 1,500,000 $ 2,000,000