Annual report pursuant to Section 13 and 15(d)

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

v3.6.0.2
SENIOR AND CONVERTIBLE SENIOR NOTES - Schedule of Senior and Convertible Senior Notes (Details) - Senior Notes [Member] - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Debt Instrument [Line Items]    
Net debt issuance costs $ (8,230) $ (10,745)
Senior and convertible senior notes, net 1,095,119 1,093,173
4.50% senior notes due 2018 [Member]    
Debt Instrument [Line Items]    
Senior and convertible senior notes, gross 175,000 175,000
7.15% senior notes due 2020 [Member]    
Debt Instrument [Line Items]    
Senior and convertible senior notes, gross 301,849 302,418
7.00% senior notes due 2022 [Member]    
Debt Instrument [Line Items]    
Senior and convertible senior notes, gross 300,000 300,000
6.00% senior notes due 2025 [Member]    
Debt Instrument [Line Items]    
Senior and convertible senior notes, gross 200,000 200,000
1.875% convertible senior notes due 2032 [Member]    
Debt Instrument [Line Items]    
Senior and convertible senior notes, gross $ 126,500 $ 126,500