Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	$ 117,611	$ (13,465)	$ 301,598	$ (237,315)
Income (Loss) Attributable to Noncontrolling Interest	(8,740)	521	(16,216)	9,517
Net gain on sales of real estate properties	113,641	0	128,544	0
Allocation Of Net Income Loss To Noncontrolling Interests Partially Owned Properties	(708)	311	(1,800)	1,101
Dividends, Preferred Stock	(1,037)	(1,037)	(3,109)	(3,109)
Income (Loss) from Continuing Operations Attributable to Parent	220,767	(13,670)	409,017	(229,806)
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	(60)	389,825	1,443	1,946,334
Net Income Loss Available To Common Stockholder Basic	220,707	376,155	410,460	1,716,528
Income From Continuing Operations Available To Common Shares	229,507		425,233
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	(62)	405,182	1,500	2,026,798
Net Income (Loss) Available to Common Stockholders, Diluted	229,445	376,155	426,733	1,716,528
Weighted Average Number of Shares Outstanding, Basic	361,409	359,811	360,900	352,414
Dilutive Op Units	13,707		13,726
Dilutive Securities Options	2,838		2,602
Weighted Average Number of Shares Outstanding, Diluted	377,954	359,811	377,228	352,414
Earnings Per Share, Basic	$ 0.611	$ 1.045	$ 1.137	$ 4.871
Earnings Per Share, Diluted	$ 0.607	$ 1.045	$ 1.131	$ 4.871
Income (loss) from continuing operations available to Common Shares	$ 0.611	$ (0.038)	$ 1.133	$ (0.652)
Income (Loss) from Discontinued Operations, Net of Tax, Per Basic Share	$ 0.000	$ 1.083	$ 0.004	$ 5.523
Income (loss) from continuing operations available to Common Shares	$ 0.607	$ (0.038)	$ 1.127	$ (0.652)
Income (Loss) from Discontinued Operations, Net of Tax, Per Diluted Share	$ 0.000	$ 1.083	$ 0.004	$ 5.523
OPERATING PARTNERSHIP
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	117,611	(13,465)	301,598	(237,315)
Net gain on sales of real estate properties	113,641	0	128,544	0
Allocation Of Net Income Loss To Noncontrolling Interests Partially Owned Properties	(708)	311	(1,800)	1,101
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	(62)	405,182	1,500	2,026,798
Dilutive Securities Options	2,838		2,602
Earnings Per Share, Basic	$ 0.611	$ 1.045	$ 1.137	$ 4.871
Earnings Per Share, Diluted	$ 0.607	$ 1.045	$ 1.131	$ 4.871
Income (loss) from continuing operations available to Common Shares	$ 0.611	$ (0.038)	$ 1.133	$ (0.652)
Income (loss) from continuing operations available to Common Shares	$ 0.607	$ (0.038)	$ 1.127	$ (0.652)
Dividend preference units	(1,037)	(1,037)	(3,109)	(3,109)
Income (Loss) From Continuing Operations Available To Units	229,507	(14,191)	425,233	(239,323)
Net Income loss available to Op unitholders basic diluted numerator	$ 229,445	$ 390,991	$ 426,733	$ 1,787,475
Weighted Average Limited Partnership and General Partnership Units Outstanding, Basic	375,116	373,547	374,626	366,150
Weighted Average Number Of Limited Partnership And General Partnership Unit Outstanding Diluted	377,954	373,547	377,228	366,150
Income (Loss) from Discontinued Operations, Net of Tax, Per Outstanding Limited Partnership and General Partnership Unit, Basic	$ 0.000	$ 1.083	$ 0.004	$ 5.523
Income Loss From Discontinued Operations Net Of Tax Per Outstanding Limited Partnership And General Partnership Diluted	$ 0.000	$ 1.083	$ 0.004	$ 5.523