Summary Of Significant Accounting Policies (Narrative) (Details) (USD $)	9 Months Ended
	Sep. 30, 2012 segment	Dec. 31, 2011
Summary Of Significant Accounting Policies [Line Items]
Restricted cash and cash equivalents	$ 167,706,000	$ 104,679,000
Write-off period for no forecasted future cash flows	10 years
Unamortized debt issuance expense	18,800,000	18,100,000
Uninsured cash and cash equivalents	3,500,000	4,100,000
Number of Reportable Segments	1
Restricted Cash And Cash Equivalents [Member]
Summary Of Significant Accounting Policies [Line Items]
Uninsured cash and cash equivalents	$ 146,700,000	$ 97,500,000
Senior Notes [Member]
Summary Of Significant Accounting Policies [Line Items]
Senior notes stated interest rate	9.125%