Annual report pursuant to Section 13 and 15(d)

SENIOR NOTES, NET - Narrative (Details)

v3.20.4
SENIOR NOTES, NET - Narrative (Details) - USD ($)
1 Months Ended 3 Months Ended 12 Months Ended
Jun. 30, 2017
Dec. 31, 2020
Mar. 31, 2018
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Jun. 30, 2015
Dec. 31, 2013
Apr. 30, 2012
Dec. 31, 2011
Debt Instrument [Line Items]                    
Percentage of wholly owned subsidiary   100.00%   100.00%            
Loss on extinguishment of debt       $ 0 $ 5,635,000 $ 0        
Senior Notes [Member] | 7.15% senior notes due 2020 [Member]                    
Debt Instrument [Line Items]                    
Aggregate principal amount of offering                   $ 200,000,000.0
Debt instrument, stated rate                   7.15%
Add-on to existing 7.50% senior notes               $ 100,000,000.0    
Effective percentage of debt instrument                   7.50%
Loss on extinguishment of debt   $ 5,600,000                
Senior Notes [Member] | 7.00% senior notes due 2022 [Member]                    
Debt Instrument [Line Items]                    
Aggregate principal amount of offering                 $ 300,000,000.0  
Debt instrument, stated rate   7.00%   7.00% 7.00%       7.00%  
Senior Notes [Member] | 6.25% senior notes due 2015 [Member]                    
Debt Instrument [Line Items]                    
Debt instrument, stated rate                 6.25%  
Aggregate principal amount repurchased                 $ 285,000,000.0  
Senior Notes [Member] | 7.731% senior subordinated notes due 2017 [Member]                    
Debt Instrument [Line Items]                    
Debt instrument, stated rate                 7.731%  
Aggregate principal amount repurchased                 $ 26,100,000  
Senior Notes [Member] | 6.00% senior notes due 2025 [Member]                    
Debt Instrument [Line Items]                    
Aggregate principal amount of offering   $ 200,000,000.0   $ 200,000,000.0     $ 200,000,000.0      
Debt instrument, stated rate   6.00%   6.00% 6.00%   6.00%      
Senior Notes [Member] | Senior Notes Due 2025, Additional Notes [Member]                    
Debt Instrument [Line Items]                    
Aggregate principal amount of offering     $ 200,000,000.0              
Debt issuance price, percentage     103.00%              
Senior Notes [Member] | Senior Notes Due Two Thousand Twenty Five, Combined Amount [Member]                    
Debt Instrument [Line Items]                    
Aggregate principal amount of offering   $ 400,000,000.0   $ 400,000,000.0            
Debt instrument, stated rate   6.00%   6.00% 6.00%          
Senior Notes [Member] | 4.50% senior notes due 2018 [Member]                    
Debt Instrument [Line Items]                    
Debt instrument, stated rate     4.50%              
Repayments of debt     $ 175,000,000.0              
Senior Notes [Member] | 5.125% senior notes due 2027 [Member]                    
Debt Instrument [Line Items]                    
Aggregate principal amount of offering $ 300,000,000.0                  
Debt instrument, stated rate 5.125% 5.125%   5.125% 5.125%          
Senior Notes [Member] | 1.875% convertible senior notes due 2032 [Member]                    
Debt Instrument [Line Items]                    
Aggregate principal amount repurchased $ 126,500,000                  
Percentage of principal in the event of a repurchase 100.00%                  
Senior Notes [Member] | 1.875% convertible senior notes due 2032 [Member] | Privately negotiated transactions                    
Debt Instrument [Line Items]                    
Aggregate principal amount repurchased $ 51,900,000                  
Senior Notes [Member] | 1.875% convertible senior notes due 2032 [Member] | Remaining redemptions                    
Debt Instrument [Line Items]                    
Aggregate principal amount repurchased $ 74,600,000