Restricted Cash (Schedule Of Restricted Cash) (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash	$ 36,221	$ 40,848
Securitization Escrow Accounts [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash	23,843	28,583
Payment And Performance Bonds [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash	884	873
Surety Bonds And Workers Compensation [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash	$ 11,494	$ 11,392