CONVERTIBLE NOTES PAYABLE (Details) (USD $)	0 Months Ended	12 Months Ended				60 Months Ended
	Dec. 20, 2011	Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 20, 2011	Jan. 31, 2007
Convertible Notes Payable [Abstract]
Redemption of convertible notes payable		$ 0		$ (48,997,000)	$ (240,000)
Gains (Losses) on Extinguishment of Debt		(198,000)		1,268,000	0
Convertible Notes Payable		930,000	930,000	930,000
Convertible Notes Payable [Member]
Convertible Notes Payable [Abstract]
Debt Instrument, Face Amount							115,000,000
Debt Instrument, Interest Rate, Stated Percentage							3.75%
Debt Instrument, Convertible, Effective Interest Rate		6.03%
Debt Instrument, Convertible, Conversion Price		$ 29.26	$ 29.26				$ 30.86
Common Shares Trading Price, Percentage of Conversion Price For Prior to Maturity Conversion		130.00%
Measurement Period, Conversion Prior to Maturity		20 days
Consecutive Trading Period		30 days
Redemption Price, Percentage of Principal Amount Plus Accrued and Unpaid Interest			100.00%
Required Repurchase Price, Percentage of Principal Amount Plus Accrued and Unpaid Interest	100.00%					100.00%
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt, Subsequent Adjustments						11,300,000
Debt Instrument, Convertible, Carrying Amount of Equity Component					1,100,000
Interest expense relating to contractual interest coupon		0		1,500,000	1,900,000
Additional non-cash interest expense				800,000	1,000,000
Redemption of convertible notes payable	24,000,000	114,100,000		48,800,000
Purchase of Convertible Notes Payable, Average Discount Rate		11.00%	11.00%
Gains (Losses) on Extinguishment of Debt				$ (400,000)