Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2011

Schedule of Quarterly Financial Information [Table Text Block]

	First Quarter			Second Quarter		Third Quarter		Fourth Quarter
2011	3/31			6/30		9/30		12/31
Total revenues (1)	$	471,230		$	489,353	$	509,623	$	519,257
Operating income (1)	117,910			143,295		149,979		162,148
(Loss) income from continuing operations (1)	(7,569		)	18,185		34,416		38,966
Discontinued operations, net (1)	140,635			563,568		78,561		68,435
Net income *	133,066			581,753		112,977		107,401
Net income available to Common Shares	123,865			552,457		104,382		99,016
Earnings per share – basic:
Net income available to Common Shares	$	0.42		$	1.88	$	0.35	$	0.33
Weighted average Common Shares outstanding	292,895			294,663		295,831		295,990
Earnings per share – diluted:
Net income available to Common Shares	$	0.42		$	1.85	$	0.35	$	0.33
Weighted average Common Shares outstanding	292,895			312,199		312,844		312,731

(1) The amounts presented for the first three quarters of 2011 are not equal to the same amounts previously reported in the respective Form 10-Q’s filed with the SEC for each period as a result of changes in discontinued operations due to additional property sales which occurred throughout 2011. Below is a reconciliation to the amounts previously reported:

	First Quarter			Second Quarter			Third Quarter
2011	3/31			6/30			9/30
Total revenues previously reported in Form 10-Q	$	520,623		$	498,059		$	511,958
Total revenues subsequently reclassified to discontinued operations	(49,393		)	(8,706		)	(2,335		)
Total revenues disclosed in Form 10-K	$	471,230		$	489,353		$	509,623
Operating income previously reported in Form 10-Q	$	133,510		$	146,495		$	151,076
Operating income subsequently reclassified to discontinued operations	(15,600		)	(3,200		)	(1,097		)
Operating income disclosed in Form 10-K	$	117,910		$	143,295		$	149,979
Income from continuing operations previously reported in Form 10-Q	$	7,727		$	21,195		$	35,491
Income from continuing operations subsequently reclassified to discontinued    operations	(15,296		)	(3,010		)	(1,075		)
(Loss) income from continuing operations disclosed in Form 10-K	$	(7,569	)	$	18,185		$	34,416
Discontinued operations, net previously reported in Form 10-Q	$	125,339		$	560,558		$	77,486
Discontinued operations, net from properties sold subsequent to the respective    reporting period	15,296			3,010			1,075
Discontinued operations, net disclosed in Form 10-K	$	140,635		$	563,568		$	78,561

	First Quarter			Second Quarter			Third Quarter			Fourth Quarter
2010	3/31			6/30			9/30			12/31
Total revenues (2)	$	421,517		$	439,258		$	451,745		$	460,748
Operating income (2)	97,540			97,590			104,444			76,503
(Loss) from continuing operations (2)	(21,315		)	(12,607		)	(1,088		)	(48,416		)
Discontinued operations, net (2)	79,171			22,696			30,914			246,628
Net income *	57,856			10,089			29,826			198,212
Net income available to Common Shares	51,863			6,343			25,166			185,870
Earnings per share – basic:
Net income available to Common Shares	$	0.18		$	0.02		$	0.09		$	0.65
Weighted average Common Shares outstanding	280,645			282,217			282,717			285,916
Earnings per share – diluted:
Net income available to Common Shares	$	0.18		$	0.02		$	0.09		$	0.65
Weighted average Common Shares outstanding	280,645			282,217			282,717			285,916

(2) The amounts presented for the four quarters of 2010 are not equal to the same amounts previously reported in the Form 8-K filed with the SEC on November 10, 2011 for each period primarily as a result of changes in discontinued operations due to additional property sales which occurred throughout 2011. Below is a reconciliation to the amounts previously reported:

	First Quarter			Second Quarter			Third Quarter			Fourth Quarter
2010	3/31			6/30			9/30			12/31
Total revenues previously reported in November 2011 Form 8-K	$	423,596		$	441,417		$	453,960		$	462,960
Total revenues subsequently reclassified to discontinued operations	(2,079		)	(2,159		)	(2,215		)	(2,212		)
Total revenues disclosed in Form 10-K	$	421,517		$	439,258		$	451,745		$	460,748
Operating income previously reported in November 2011 Form 8-K	$	98,210		$	98,413		$	105,264		$	77,444
Operating income subsequently reclassified to discontinued    operations	(670		)	(823		)	(820		)	(941		)
Operating income disclosed in Form 10-K	$	97,540		$	97,590		$	104,444		$	76,503
(Loss) from continuing operations previously reported in    November 2011 Form 8-K	$	(20,676	)	$	(11,697	)	$	(295	)	$	(47,511	)
Income from continuing operations subsequently reclassified to     discontinued operations	(639		)	(910		)	(793		)	(905		)
(Loss) from continuing operations disclosed in Form 10-K	$	(21,315	)	$	(12,607	)	$	(1,088	)	$	(48,416	)
Discontinued operations, net previously reported in November 2011     Form 8-K	$	78,532		$	21,786		$	30,121		$	245,723
Discontinued operations, net from properties sold subsequent to the     respective reporting period	639			910			793			905
Discontinued operations, net disclosed in Form 10-K	$	79,171		$	22,696		$	30,914		$	246,628

* The Company did not have any extraordinary items or cumulative effect of change in accounting principle during the years ended December 31, 2011 and 2010. Therefore, income before extraordinary items and cumulative effect of change in accounting principle is not shown as it was equal to the net income amounts disclosed above.

Operating Partnership [Member]

Schedule of Quarterly Financial Information [Table Text Block]

	First Quarter			Second Quarter		Third Quarter		Fourth Quarter
2011	3/31			6/30		9/30		12/31
Total revenues (1)	$	471,230		$	489,353	$	509,623	$	519,257
Operating income (1)	117,910			143,295		149,979		162,148
(Loss) income from continuing operations (1)	(7,569		)	18,185		34,416		38,966
Discontinued operations, net (1)	140,635			563,568		78,561		68,435
Net income *	133,066			581,753		112,977		107,401
Net income available to Units	129,640			578,215		109,124		103,521
Earnings per Unit – basic:
Net income available to Units	$	0.42		$	1.88	$	0.35	$	0.33
Weighted average Units outstanding	306,248			307,954		308,884		309,120
Earnings per Unit – diluted:
Net income available to Units	$	0.42		$	1.85	$	0.35	$	0.33
Weighted average Units outstanding	306,248			312,199		312,844		312,731

(1) The amounts presented for the first three quarters of 2011 are not equal to the same amounts previously reported in the respective Form 10-Q’s filed with the SEC for each period as a result of changes in discontinued operations due to additional property sales which occurred throughout 2011. Below is a reconciliation to the amounts previously reported:

	First Quarter			Second Quarter			Third Quarter
2011	3/31			6/30			9/30
Total revenues previously reported in Form 10-Q	$	520,623		$	498,059		$	511,958
Total revenues subsequently reclassified to discontinued operations	(49,393		)	(8,706		)	(2,335		)
Total revenues disclosed in Form 10-K	$	471,230		$	489,353		$	509,623
Operating income previously reported in Form 10-Q	$	133,510		$	146,495		$	151,076
Operating income subsequently reclassified to discontinued operations	(15,600		)	(3,200		)	(1,097		)
Operating income disclosed in Form 10-K	$	117,910		$	143,295		$	149,979
Income from continuing operations previously reported in Form 10-Q	$	7,727		$	21,195		$	35,491
Income from continuing operations subsequently reclassified to discontinued    operations	(15,296		)	(3,010		)	(1,075		)
(Loss) income from continuing operations disclosed in Form 10-K	$	(7,569	)	$	18,185		$	34,416
Discontinued operations, net previously reported in Form 10-Q	$	125,339		$	560,558		$	77,486
Discontinued operations, net from properties sold subsequent to the respective    reporting period	15,296			3,010			1,075
Discontinued operations, net disclosed in Form 10-K	$	140,635		$	563,568		$	78,561

	First Quarter			Second Quarter			Third Quarter			Fourth Quarter
2010	3/31			6/30			9/30			12/31
Total revenues (2)	$	421,517		$	439,258		$	451,745		$	460,748
Operating income (2)	97,540			97,590			104,444			76,503
(Loss) from continuing operations (2)	(21,315		)	(12,607		)	(1,088		)	(48,416		)
Discontinued operations, net (2)	79,171			22,696			30,914			246,628
Net income *	57,856			10,089			29,826			198,212
Net income available to Units	54,486			6,656			26,397			194,802
Earnings per Unit – basic:
Net income available to Units	$	0.18		$	0.02		$	0.09		$	0.65
Weighted average Units outstanding	294,450			295,898			296,348			299,363
Earnings per Unit – diluted:
Net income available to Units	$	0.18		$	0.02		$	0.09		$	0.65
Weighted average Units outstanding	294,450			295,898			296,348			299,363

(2) The amounts presented for the four quarters of 2010 are not equal to the same amounts previously reported in the Form 10-K filed with the SEC on February 24, 2011 for each period primarily as a result of changes in discontinued operations due to additional property sales which occurred throughout 2011. Below is a reconciliation to the amounts previously reported:

	First Quarter			Second Quarter			Third Quarter			Fourth Quarter
2010	3/31			6/30			9/30			12/31
Total revenues previously reported in 2010 Form 10-K	$	472,082		$	494,541		$	511,772		$	517,124
Total revenues subsequently reclassified to discontinued operations	(50,565		)	(55,283		)	(60,027		)	(56,376		)
Total revenues disclosed in Form 10-K	$	421,517		$	439,258		$	451,745		$	460,748
Operating income previously reported in 2010 Form 10-K	$	112,382		$	115,247		$	121,047		$	93,325
Operating income subsequently reclassified to discontinued    operations	(14,842		)	(17,657		)	(16,603		)	(16,822		)
Operating income disclosed in Form 10-K	$	97,540		$	97,590		$	104,444		$	76,503
(Loss) income from continuing operations previously reported in     2010 Form 10-K	$	(7,267	)	$	4,714		$	14,930		$	(32,221	)
Income from continuing operations subsequently reclassified to     discontinued operations	(14,048		)	(17,321		)	(16,018		)	(16,195		)
(Loss) from continuing operations disclosed in Form 10-K	$	(21,315	)	$	(12,607	)	$	(1,088	)	$	(48,416	)
Discontinued operations, net previously reported in 2010 Form 10-K	$	65,123		$	5,375		$	14,896		$	230,433
Discontinued operations, net from properties sold subsequent to the     respective reporting period	14,048			17,321			16,018			16,195
Discontinued operations, net disclosed in Form 10-K	$	79,171		$	22,696		$	30,914		$	246,628

* The Operating Partnership did not have any extraordinary items or cumulative effect of change in accounting principle during the years ended December 31, 2011 and 2010. Therefore, income before extraordinary items and cumulative effect of change in accounting principle is not shown as it was equal to the net income amounts disclosed above.