Annual report pursuant to Section 13 and 15(d)

Fair Value of Financial Instruments (Details)

v3.10.0.1
Fair Value of Financial Instruments (Details) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Debt Instrument [Line Items]    
Deferred finance costs $ 30,733 $ 34,781
Senior notes | 6.625% Senior Notes Due 2023    
Debt Instrument [Line Items]    
Deferred finance costs 4,400  
Senior notes | 6.000% Senior Notes Due 2024    
Debt Instrument [Line Items]    
Deferred finance costs 8,700  
Senior notes | 6.375% Senior Notes Due 2025    
Debt Instrument [Line Items]    
Deferred finance costs 12,500  
Senior notes | 6.375% Senior Notes Due 2026    
Debt Instrument [Line Items]    
Deferred finance costs 5,000  
Carrying value | Senior notes    
Debt Instrument [Line Items]    
Fair value of notes 2,000,000  
Fair value | Senior notes    
Debt Instrument [Line Items]    
Fair value of notes $ 1,800,000