Marketable Securities (Schedule Of Marketable Securities Classified As Cash Equivalents) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Gain (Loss) on Investments [Line Items]
Cost	$ 886,000	$ 2,824,000
Unrealized Gains
Unrealized Losses
Recorded Basis	886,000	2,824,000
Corporate Debt Securities And Certificates Of Deposit [Member]
Gain (Loss) on Investments [Line Items]
Cost	886,000	2,824,000
Unrealized Gains
Unrealized Losses
Recorded Basis	$ 886,000	$ 2,824,000