Stock Transactions (Summary Of Convertible Preferred Stock) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2009	Dec. 31, 2011	Dec. 31, 2010
Class of Stock [Line Items]
Preferred stock, Gross Proceeds	$ 102,000
Preferred stock, shares issued		0	0
Cumulative Dividends at December 31, 2009	51,177
Series D-1 Through D-3 Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, Date Of Issuance	June 29, 2005
Preferred stock, Gross Proceeds
Preferred stock, Net Proceeds
Preferred stock, shares issued	5,865,785
Cumulative Dividends at December 31, 2009	23,453
Series D-4 Preferred Stock Issued On June 29, 2005 [Member]
Class of Stock [Line Items]
Preferred stock, Date Of Issuance	June 29, 2005
Preferred stock, Gross Proceeds
Preferred stock, Net Proceeds
Preferred stock, shares issued	5,769,231
Cumulative Dividends at December 31, 2009	18,678
Series D-4 Preferred Stock Issued On September 7, 2006 [Member]
Class of Stock [Line Items]
Preferred stock, Date Of Issuance	September 7, 2006
Preferred stock, Gross Proceeds
Preferred stock, Net Proceeds
Preferred stock, shares issued	575,854
Cumulative Dividends at December 31, 2009	1,368
Series D-4 Preferred Stock Issued On December 19, 2006 [Member]
Class of Stock [Line Items]
Preferred stock, Date Of Issuance	December 19, 2006
Preferred stock, Gross Proceeds
Preferred stock, Net Proceeds
Preferred stock, shares issued	1,819,196
Cumulative Dividends at December 31, 2009	3,821
Series E Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, Date Of Issuance	April 1, 2009
Preferred stock, Gross Proceeds	102,000
Preferred stock, Net Proceeds	94,000
Preferred stock, shares issued	3,400,000
Cumulative Dividends at December 31, 2009	$ 3,857