Quarterly report pursuant to Section 13 or 15(d)

SENIOR AND CONVERTIBLE SENIOR NOTES, NET - Schedule of Senior and Convertible Senior Notes, Net (Details)

v3.7.0.1
SENIOR AND CONVERTIBLE SENIOR NOTES, NET - Schedule of Senior and Convertible Senior Notes, Net (Details) - Senior Notes [Member] - USD ($)
$ in Thousands
Mar. 31, 2017
Dec. 31, 2016
Debt Instrument [Line Items]    
Net debt issuance costs $ (7,601) $ (8,230)
Senior and convertible senior notes, net 1,095,606 1,095,119
4.50% senior notes due 2018 [Member]    
Debt Instrument [Line Items]    
Senior and convertible senior notes, gross $ 175,000 $ 175,000
Debt instrument, stated rate (percent) 4.50% 4.50%
7.15% senior notes due 2020 [Member]    
Debt Instrument [Line Items]    
Senior and convertible senior notes, gross $ 301,707 $ 301,849
Debt instrument, stated rate (percent) 7.15% 7.15%
Unamortized premium $ 1,707 $ 1,849
7.00% senior notes due 2022 [Member]    
Debt Instrument [Line Items]    
Senior and convertible senior notes, gross $ 300,000 $ 300,000
Debt instrument, stated rate (percent) 7.00% 7.00%
6.00% senior notes due 2025 [Member]    
Debt Instrument [Line Items]    
Senior and convertible senior notes, gross $ 200,000 $ 200,000
Debt instrument, stated rate (percent) 6.00% 6.00%
1.875% convertible senior notes due 2032 [Member]    
Debt Instrument [Line Items]    
Senior and convertible senior notes, gross $ 126,500 $ 126,500
Debt instrument, stated rate (percent) 1.875% 1.875%