Cash Equivalents And Restricted Cash And Securities (Summary Of Cash Equivalents And Marketable Securities) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 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
Unrealized Holding Gains (Losses)
Estimated Market Value	5,000	5,000
Money Market Funds [Member] | Cash Equivalents [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Cost Basis	892	5,349
Unrealized Holding Gains (Losses)
Estimated Market Value	892	5,349
Money Market Funds [Member] | Restricted Cash And Securities [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Cost Basis	973	350
Unrealized Holding Gains (Losses)
Estimated Market Value	973	350
Certificates Of Deposit [Member] | Cash Equivalents [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Cost Basis		749
Unrealized Holding Gains (Losses)
Estimated Market Value		749
U.S. Treasury Debt Securities [Member] | Cash Equivalents [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Cost Basis	22,000
Unrealized Holding Gains (Losses)
Estimated Market Value	$ 22,000