Investments In Unconsolidated Real Estate Entities (Schedule Of Operation For Apartment LLCs) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Revenues
Rental	$ 81,069	$ 73,607	$ 233,805	$ 213,199
Other property revenues	5,096	4,762	14,368	13,682
Total revenues	86,374	78,612	248,810	227,567
Expenses
Property operating and maintenance	37,341	34,618	107,209	100,441
Interest	11,816	14,207	34,564	43,119
Total expenses	62,188	57,979	180,476	171,447
Net income (loss)	22,207	8,794	65,086	21,565
Company's share of net income in Apartment LLCs	475	235	7,416	790
Apartment LLCs [Member]
Revenues
Rental	6,226	5,932	18,421	17,543
Other property revenues	476	474	1,411	1,382
Total revenues	6,702	6,406	19,832	18,925
Expenses
Property operating and maintenance	2,651	2,586	7,733	7,380
Depreciation and amortization	1,368	1,488	4,400	4,441
Interest	2,278	2,583	6,903	7,664
Total expenses	6,297	6,657	19,036	19,485
Net loss from continuing operations	405	(251)	796	(560)
Gain (loss) from discontinued operations		(28)	21,607	(127)
Net income (loss)	405	(279)	22,403	(687)
Company's share of net income in Apartment LLCs	$ 475	$ 235	$ 7,416	$ 790