Equity And Other Investments (Schedule Of Investment Activity In Affiliates) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Schedule Of Equity And Other Investments [Line Items]
Beginning balance	$ 18,385,000	$ 16,938,000.000	$ 14,901,000
Equity in net income	7,255,000	7,092,000	7,637,000
Impairment of investment	(3,477,000)
Ending balance	14,913,000	18,385,000	16,938,000.000
Distributions	(7,250,000)	(7,425,000)	(9,000,000)
Cash investments		1,780,000	3,400,000
Scarborough [Member]
Schedule Of Equity And Other Investments [Line Items]
Equity in net income	7,255,000	7,092,000	7,637,000
Beginning balance	13,205,000	13,538,000.000	14,901,000
Distributions	(7,250,000)	(7,425,000)	(9,000,000)
Ending balance	13,210,000	13,205,000	13,538,000.000
Cash investments
TRA [Member]
Schedule Of Equity And Other Investments [Line Items]
Impairment of investment	(3,477,000)
Beginning balance	5,180,000	3,400,000.000
Cash investments		1,780,000	3,400,000
Ending balance	$ 1,703,000	$ 5,180,000	$ 3,400,000.000