Segment Reporting (Schedule Of Assets For The Reportable Segments) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Total assets	$ 3,019,631	$ 2,983,228
Owned And Managed [Member]
Segment Reporting Information [Line Items]
Total assets	2,711,926	2,698,509
Managed-Only [Member]
Segment Reporting Information [Line Items]
Total assets	125,637	127,960
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Total assets	180,220	154,598
Discontinued Operations [Member]
Segment Reporting Information [Line Items]
Total assets	$ 1,848	$ 2,161