Restricted Cash (Schedule Of Restricted Cash) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash	$ 39,861	$ 28,580
Restricted Cash - Current Asset [Member] \| Securitization Escrow Accounts [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash	36,607	25,135
Restricted Cash - Current Asset [Member] \| Payment and Performance Bonds [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash	179	218
Other Assets - Noncurrent [Member] \| Surety Bonds and Workers Compensation [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash	$ 3,075	$ 3,227

The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. This element is for unclassified presentations; for classified presentations there is a separate and distinct element.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.1)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_RestrictedCashAndCashEquivalents
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant