Discontinued Operations (Details) (USD $)	3 Months Ended							12 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
REVENUES
Disposal Group Including Discontinued Operation Rental Revenue								$ 121,942,000	$ 445,832,000	$ 560,399,000
Disposal Group, Including Discontinued Operation, Revenue								121,942,000	445,832,000	560,399,000
EXPENSES
Disposal Group Including Discontinued Operation Property And Maintenance								36,792,000	103,371,000	160,315,000
Disposal Group Including Discontinued Operation Real Estate Taxes And Insurance								11,903,000	41,208,000	50,173,000
Disposal Group Including Discontinued Operations Property Management								1,000	211,000	266,000
Disposal Group Including Discontinued Operation Depreciation								34,380,000	124,323,000	157,441,000
Disposal Group Including Discontinued Operation General And Administrative								85,000	92,000	55,000
Disposal Group, Including Discontinued Operation, Operating Expense								83,161,000	269,205,000	368,250,000
Disposal Group, Including Discontinued Operation, Operating Income (Loss)								38,781,000	176,627,000	192,149,000
Disposal Group Including Discontinued Operation Interest And Other Income								217,000	156,000	198,000
Disposal Group Including Discontinued Operation Other Expenses								(3,000)	(170,000)	(421,000)
Interest:
Expense incurred, net								(1,296,000)	(3,811,000)	(9,268,000)
Disposal Group Including Discontinued Operation Amortization Of Deferred Financing Costs								(228,000)	(140,000)	(1,230,000)
Discontinued Operation, Tax Effect of Discontinued Operation								(449,000)	(34,000)	221,000
Income Loss From Discontinued Operations								37,022,000	172,628,000	181,649,000
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax								2,036,505,000	548,278,000	826,489,000
Discontinued operations, net	405,182,000	395,243,000	1,226,373,000	283,636,000	145,054,000	114,655,000	177,561,000	2,073,527,000	720,906,000	1,008,138,000
Disposal Group, Including Discontinued Operation, Property, Plant, and Equipment, Net								2,000,000,000
Disposal Group Including Discontinued Operation Mortgage Notes Payable				$ 34,400,000					$ 34,400,000