Investment In Real Estate Joint Ventures And Partnerships (Schedule Of Combined Condensed Statements Of Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Investment In Real Estate Joint Ventures And Partnerships [Line Items]
Revenues, net	$ 131,918	[1]	$ 129,434	[1]	$ 123,163	[1]	$ 119,023	[1]	$ 119,729	[1]	$ 122,851	[1]	$ 120,964	[1]	$ 114,813	[1]	$ 503,538	$ 478,357	$ 471,284
Expenses:
Depreciation and amortization																	140,983	131,350	125,302
Interest, net																	115,812	139,717	145,391
Operating																	98,426	89,998	90,881
Real estate taxes, net																	58,077	55,522	53,173
General and administrative																	28,554	25,477	24,944
Provision for income taxes																	79	146	(82)
Impairment loss																	9,982	55,574	33,317
Total																	336,022	357,921	327,617
Operating (loss) income																	72,187	(6,531)	20,935
Unconsolidated Real Estate Joint Ventures [Member]
Investment In Real Estate Joint Ventures And Partnerships [Line Items]
Revenues, net																	195,109	205,596	193,649
Expenses:
Depreciation and amortization																	59,330	67,459	61,726
Interest, net																	35,491	37,612	36,270
Operating																	34,989	36,253	34,026
Real estate taxes, net																	23,899	24,333	24,288
General and administrative																	1,106	2,969	3,927
Provision for income taxes																	316	343	237
Impairment loss																	96,781	28,776	231
Total																	251,912	197,745	160,705
Operating (loss) income																	$ (56,803)	$ 7,851	$ 32,944

[1] Revenues from the sale of operating properties have been reclassified and reported in discontinued operations for all periods presented.