Annual report pursuant to Section 13 and 15(d)

Long-term Debt - Summary of Components of Convertible Notes (Details)

v3.19.3.a.u2
Long-term Debt - Summary of Components of Convertible Notes (Details) - USD ($)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Sep. 30, 2019
Jul. 31, 2019
Debt Instrument [Line Items]          
Interest expense $ 64,241,000 $ 76,874,000 $ 65,472,000    
Senior Unsecured Notes          
Debt Instrument [Line Items]          
Principal       $ 150,000,000  
Senior Unsecured Notes | 2024 Notes          
Debt Instrument [Line Items]          
Principal 500,000,000       $ 350,000,000
Accrued interest 13,000,000        
Unamortized premium 7,000,000        
Less: Unamortized financing costs (8,000,000)        
Carrying value of convertible notes 512,000,000        
Interest expense 12,000,000        
Convertible Notes Payable | 4.125% Convertible Senior Notes Due September 1, 2022          
Debt Instrument [Line Items]          
Principal 150,000,000 150,000,000      
Accrued interest 2,000,000 2,000,000      
Less: Unamortized financing costs (3,000,000) (4,000,000)      
Carrying value of convertible notes 149,000,000 148,000,000      
Interest expense $ 7,000,000 $ 7,000,000