Investments In Unconsolidated Real Estate Entities (Schedule Of Operation For Apartment LLCs) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Real Estate Properties [Line Items]
Rental	$ 75,655	$ 69,093
Other property revenues	4,399	4,222
Other	222	216
Total revenues	80,276	73,531
Property operating and maintenance	34,637	32,617
Interest	11,645	14,475
Total expenses	59,049	56,457
Net income (loss)	21,800	3,025
Company's share of net income in Apartment LLCs	6,446	209
Apartment LLCs [Member]
Real Estate Properties [Line Items]
Rental	6,042	5,769
Other property revenues	436	425
Total revenues	6,478	6,194
Property operating and maintenance	2,527	2,463
Depreciation and amortization	1,606	1,473
Interest	2,367	2,526
Total expenses	6,500	6,462
Net loss from continuing operations	(22)	(268)
Gain (loss) from discontinued operations	21,607	(57)
Net income (loss)	21,585	(325)
Company's share of net income in Apartment LLCs	$ 6,446	$ 209