Restricted Cash (Schedule Of Restricted Cash) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash	$ 58,453	$ 56,296
Restricted Cash - Current Asset [Member] | Securitization Escrow Accounts [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash	52,117	46,364
Restricted Cash - Current Asset [Member] | Payment and Performance Bonds [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash	402	941
Other Assets - Noncurrent [Member] | Surety Bonds and Workers Compensation [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash	$ 5,934	$ 8,991