Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt (Summary of Debt) (Details)

v3.10.0.1
Long-Term Debt (Summary of Debt) (Details) - USD ($)
$ in Thousands
Sep. 30, 2018
Dec. 31, 2017
Debt Instrument [Line Items]    
Outstanding Principal $ 2,975,662  
Deferred financing costs (2,719) $ 0
Total debt 3,052,506 0
Debt classified as current (included in other current liabilities) (2,959) 0
Total long-term debt 3,049,547 0
Margin Loan Facility    
Debt Instrument [Line Items]    
Outstanding Principal 1,000,000  
Carrying Value 1,000,000 $ 0
Exchangeable senior debentures    
Debt Instrument [Line Items]    
Outstanding Principal 477,250  
Carrying Value 527,361  
Senior notes    
Debt Instrument [Line Items]    
Outstanding Principal 775,000  
Carrying Value 804,450  
Senior credit facility    
Debt Instrument [Line Items]    
Outstanding Principal 715,739  
Carrying Value 715,739  
Wells Fargo note payable    
Debt Instrument [Line Items]    
Outstanding Principal 7,673  
Carrying Value $ 7,675