Long-Term Debt Convertible Debt (Details) (USD $)	3 Months Ended							12 Months Ended				12 Months Ended			60 Months Ended		12 Months Ended
	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011 Convertible Subordinated Debt [Member]	Dec. 31, 2011 Convertible Subordinated Debt [Member] Convertible Senior Subordinated Debentures February 2027 [Member]	Dec. 31, 2010 Convertible Subordinated Debt [Member] Convertible Senior Subordinated Debentures February 2027 [Member]	Dec. 31, 2009 Convertible Subordinated Debt [Member] Convertible Senior Subordinated Debentures February 2027 [Member]	Dec. 31, 2011 Convertible Subordinated Debt [Member] Convertible Senior Subordinated Debentures February 2027 [Member]	Feb. 17, 2007 Convertible Subordinated Debt [Member] Convertible Senior Subordinated Debentures February 2027 [Member]	Dec. 31, 2011 Convertible Subordinated Debt [Member] Convertible Senior Subordinated Debentures February 2027 [Member] Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount												$ 4,053,000	$ 25,137,000		$ 4,053,000
Effective Interest Rate															11.50%
Principal Amount																135,000,000
Interest Rate												4.125%	4.125%	4.125%
Principal in Excess of If-converted Value												5,307,000			5,307,000
Extinguishment of Debt									100,000,000			63,351,000
Repurchased and Extinguished Principal												63,351,000	57,799,000
Principal amount of liability component												13,850,000	77,201,000		13,850,000
Gains (Losses) on Extinguishment of Debt	(7,462,000)	(11,855,000)	(4,881,000)	(18,019,000)	(3,711,000)	(14,048,000)	(4,386,000)	(24,200,000)	(40,164,000)	(2,878,000)		(24,200,000)
Write off of Deferred Debt Issuance Cost												1,554,000
Conversion Ratio												40.3323
Conversion Ratio Principal Amount												1,000			1,000
Initial Conversion Price											$ 24.79	$ 24.79			$ 24.79
Interest Expense												1,565,000	3,198,000	4,142,000
Interest Paid								$ 10,789,000	$ 28,341,000	$ 33,188,000		$ 1,670,000	$ 4,178,000	$ 5,569,000
Stated Interest Rate Percentage												4.25%			4.25%
Conversion Price												$ 32.23			$ 32.23
Conversion Price Premium												30.00%			30.00%
Trading Days Common Stock above Conversion Price																	20 days
Period of Consecutive Trading Days Preceding the Date on which the Notice of Conversion is Given												30 days
Number of equity instruments upon conversion of convertible debt												559,000