Investments In Unconsolidated Real Estate Entities (Schedule Of Operations - Apartment LLCs) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009	Dec. 31, 2008
Real Estate Properties [Line Items]
Real estate assets, net of accumulated depreciation of $32,780 and $26,987 at December 31, 2011 and 2010, respectively	$ 2,075,517		$ 2,042,375
Total assets	2,139,064		2,114,779
Total liabilities	1,084,701		1,141,292
Members' equity	1,047,523		967,295		1,016,053	995,850
Total liabilities and members' equity	2,139,064		2,114,779
Credit investments	15,945		15,384
Apartment LLCs [Member]
Real Estate Properties [Line Items]
Real estate assets, net of accumulated depreciation of $32,780 and $26,987 at December 31, 2011 and 2010, respectively	217,443		221,343
Assets held for sale, net	28,846		29,308
Cash and other	6,526		6,518
Total assets	252,815		257,169
Mortgage notes payable	206,495		206,495
Other liabilities	2,737		2,460
Total liabilities	209,232		208,955
Members' equity	43,583		48,214
Total liabilities and members' equity	252,815		257,169
Company's equity investment in Apartment LLCs	(8,601)	[1]	(7,713)	[1]
Credit investments	15,945		15,384
Net accumulated depreciation	$ 32,780		$ 26,987

[1] At December 31, 2011 and 2010, the Company's equity investment includes its credit investments of $15,945 and $15,384, respectively, discussed above.