DEBT (Components of Interest Expense) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
2016 Convertible Senior Notes
Debt Instrument [Line Items]
Amortization of the discount on the liability component	$ 5,993,000	[1]	$ 3,740,000	[1]	$ 0	[1]
Cash interest related to the contractual interest coupon	3,154,000	[2]	2,024,000	[2]	0	[2]
Total	9,147,000		5,764,000		0
Amortization of debt discount, capitalized interest	1,100,000
Cash interest related to contractual interest coupon, capitalized interest	600,000
2012 Senior Convertible Notes
Debt Instrument [Line Items]
Amortization of the discount on the liability component	2,527,000	[1]	6,850,000	[1]	6,401,000	[1]
Cash interest related to the contractual interest coupon	1,378,000	[2]	3,919,000	[2]	3,919,000	[2]
Total	3,905,000		10,769,000		10,320,000
Amortization of debt discount, capitalized interest	500,000
Cash interest related to contractual interest coupon, capitalized interest	300,000
2010 Senior Convertible Notes
Debt Instrument [Line Items]
Amortization of the discount on the liability component	0		0		1,190,000
Cash interest related to the contractual interest coupon	0		0		830,000
Total	$ 0		$ 0		$ 2,020,000

[1] In 2012, the amortization of the discount on the liability component of the 2016 and 2012 Notes are presented net of capitalized interest of $1.1 million and $0.5 million, respectively.

[2] In 2012, the cash interest related to the contractual interest coupon on the 2016 and 2012 Notes are presented net of capitalized interest of $0.6 million and $0.3 million.