Annual report pursuant to Section 13 and 15(d)

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

v3.3.1.900
SENIOR AND CONVERTIBLE SENIOR NOTES - Schedule of Senior and Convertible Senior Notes (Details) - USD ($)
$ in Thousands
Dec. 31, 2015
Dec. 31, 2014
Debt Instrument [Line Items]    
Senior and convertible senior notes $ 1,103,918 $ 904,486
4.50% senior notes due 2018 [Member]    
Debt Instrument [Line Items]    
Senior and convertible senior notes 175,000 175,000
7.15% senior notes due 2020 [Member]    
Debt Instrument [Line Items]    
Senior and convertible senior notes 302,418 302,986
7.00% senior notes due 2022 [Member]    
Debt Instrument [Line Items]    
Senior and convertible senior notes 300,000 300,000
6.00% senior notes due 2025 [Member]    
Debt Instrument [Line Items]    
Senior and convertible senior notes 200,000 0
1.875% convertible senior notes due 2032 [Member]    
Debt Instrument [Line Items]    
Senior and convertible senior notes $ 126,500 $ 126,500