Property And Equipment, Net (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Property And Equipment, Net [Abstract]
Depreciation expense	$ 5,300,000	$ 5,100,000	$ 4,400,000
Expected rental income, during 2012	640,000
Expected rental income, during 2013	404,000
Expected rental income, during 2014	235,000
Expected rental income, during 2015	78,000
Expected rental income, thereafter	0
Rental income associated with third party tenants	$ 1,200,000	$ 1,400,000	$ 1,300,000