CONVERTIBLE NOTES PAYABLE (Details) (USD $)	0 Months Ended		12 Months Ended			60 Months Ended	61 Months Ended
	Dec. 31, 2011	Dec. 20, 2011	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 20, 2011	Dec. 31, 2011	Jan. 31, 2007
Convertible Notes Payable [Abstract]
Redemption of convertible notes payable			$ (48,997,000)	$ (240,000)	$ (46,736,000)
Gains (Losses) on Extinguishment of Debt			1,268,000	0	7,057,000
Convertible Notes Payable	930,000		930,000	48,712,000			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				$ 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			1,500,000	1,900,000	2,500,000
Additional non-cash interest expense			800,000	1,000,000	1,300,000
Redemption of convertible notes payable		24,000,000	48,800,000				114,100,000
Purchase of Convertible Notes Payable, Average Discount Rate	11.00%		11.00%				11.00%
Gains (Losses) on Extinguishment of Debt			(400,000)		7,100,000
Long-term Debt, Gross	$ 900,000		$ 900,000	$ 49,800,000			$ 900,000