INTEREST EXPENSE Schedule of extinguishment of debt (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Extinguishment of Debt [Line Items]
(Gain) / loss on extinguishment	$ 0	$ 924	$ (448)	$ 25,904
2013 Convertible Notes [Member]
Extinguishment of Debt [Line Items]
(Gain) / loss on extinguishment	0	924	3,763	23,516
2014 Floating Rate Notes [Member]
Extinguishment of Debt [Line Items]
(Gain) / loss on extinguishment	0	0	(4,211)	0
2016 Fixed Rate Notes [Member]
Extinguishment of Debt [Line Items]
(Gain) / loss on extinguishment	$ 0	$ 0	$ 0	$ 2,388