Real Estate And Accumulated Depreciation (Changes In Total Real Estate Assets Including Real Estate Held For Sale) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Real Estate And Accumulated Depreciation [Abstract]
Balance at beginning of period	$ 990,635	[1]	$ 934,601	[1]	$ 943,700
Acquisitions	240,474		146,854		421
Additions	1,011		1,709		5,550
Dispositions	(40,460)		(92,529)		(15,070)
Other	(564)
Balance at end of period	1,191,096		990,635	[1]	934,601	[1]
Real estate held for sale			40,460		113,151
Intangible lease assets held-for-sale			$ 1,361		$ 25,848

[1] Includes real-estate cost included in real estate held for sale of $40,460 and $113,151 for 2010 and 2009, respectively. Excludes intangible lease assets that are included in real estate held for sale of $1,361 and $25,848 for 2010 and 2009, respectively.