Cash Equivalents And Restricted Cash And Securities (Summary Of Cash Equivalents And Marketable Securities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Cash [Member] | Restricted Cash And Securities [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Cost Basis	$ 5,000	$ 5,000
Estimated Market Value	5,000	5,000
Money Market Funds [Member] | Cash Equivalents [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Cost Basis	18,213	5,349
Estimated Market Value	18,213	5,349
Money Market Funds [Member] | Restricted Cash And Securities [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Cost Basis	884	350
Estimated Market Value	884	350
Certificates Of Deposit [Member] | Cash Equivalents [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Cost Basis		749
Estimated Market Value		$ 749