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Debt - Senior Notes (Details) - USD ($)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Apr. 12, 2017
Oct. 18, 2016
May 24, 2016
Apr. 04, 2016
Sep. 24, 2015
2026 Senior Notes              
Debt Instrument [Line Items]              
Senior notes, noncurrent $ 600,000,000.0 $ 600,000,000.0     $ 600,000,000.0    
Stated percentage 5.50% 5.50%     5.50%    
Percentage of principal amount that may be redeemed 105.50%            
Minimum percentage of notes not eligible for early redemption 65.00%            
Senior notes, percent exchanged       100.00%      
2026 Senior Notes | Any time on or after June 15, 2021              
Debt Instrument [Line Items]              
Redemption price, percentage 102.75%            
2026 Senior Notes | Beginning on June 15, 2024              
Debt Instrument [Line Items]              
Redemption price, percentage 100.00%            
2026 Senior Notes | Any time prior to June 15, 2021 with a 'make-whole' premium and accrued and unpaid interest, if any              
Debt Instrument [Line Items]              
Percentage of redemption on notes 100.00%            
2026 Senior Notes | Any time prior to June 15, 2019 with the net cash proceeds from certain equity offerings plus accrued and unpaid interest, if any              
Debt Instrument [Line Items]              
Percentage of redemption on notes 35.00%            
Securitized debt              
Debt Instrument [Line Items]              
Senior notes, noncurrent $ 375,000,000.0 $ 375,000,000.0          
2023 Senior Notes              
Debt Instrument [Line Items]              
Senior notes, noncurrent $ 450,000,000.0 $ 450,000,000.0         $ 450,000,000.0
Stated percentage 5.625% 5.625%         5.625%
Senior notes, percent exchanged           100.00%  
2023 Senior Notes | Any time on or after October 15, 2018              
Debt Instrument [Line Items]              
Redemption price, percentage 104.219%            
2023 Senior Notes | Beginning on October 15, 2021              
Debt Instrument [Line Items]              
Redemption price, percentage 100.00%            
Revolver              
Debt Instrument [Line Items]              
Principal borrowing capacity, maximum     $ 120,000,000.0        
Significant Other Observable Inputs (Level 2) | 2026 Senior Notes              
Debt Instrument [Line Items]              
Notes, fair value $ 634,900,000 $ 549,300,000          
Significant Other Observable Inputs (Level 2) | 2023 Senior Notes              
Debt Instrument [Line Items]              
Notes, fair value $ 464,200,000 $ 435,600,000