Investments In Marketable Securities (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Dividend and Interest Income From Marketable Securities	$ 157,000	$ 317,000
Available-for-sale Securities, Gross Unrealized Gains	7,589,000		7,181,000
Marketable securities	11,772,000		11,364,000
Net realized gains and recoveries on sales of marketable securities	$ 0	$ 154,000