Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues:
Rental and related revenue	$ 875,194	$ 771,625	$ 686,242
General contractor and service fee revenue	206,596	275,071	521,796
Revenues, Total	1,081,790	1,046,696	1,208,038
Expenses:
Rental expenses	159,008	137,797	129,717
Real estate taxes	117,747	106,128	95,666
General contractor and other services expenses	183,833	254,870	480,480
Depreciation and amortization	393,450	349,015	305,070
Costs and expenses, total	854,038	847,810	1,010,933
Other Operating Activities
Equity in earnings of unconsolidated companies	54,116	4,674	4,565
Gain on Sale of Properties	59,179	344	68,549
Earnings from sales of land	9,547	0	0
Undeveloped land carrying costs	(8,614)	(8,829)	(8,934)
Impairment charges	(3,777)	0	(12,931)
Other Operating Income (Expense), Net	470	(633)	(1,237)
General and administrative expenses	(42,673)	(46,424)	(43,107)
Other operating transactions, total	68,248	(50,868)	6,905
Operating income (loss)	296,000	148,018	204,010
Other Nonoperating Income (Expense)
Interest and other income, net	1,887	514	658
Interest expense	(228,895)	(229,992)	(206,770)
Gains (Losses) on Extinguishment of Debt	(9,433)	0	0
Acquisition-related activity	(3,093)	(4,192)	(1,188)
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest	56,466	(85,652)	(3,290)
Income Tax Expense (Benefit)	5,080	103	194
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	61,546	(85,549)	(3,096)
Discontinued operations
Income (loss) before gain on sales	1,761	(3,786)	(1,477)
Gain on sale of depreciable properties	133,242	13,467	100,882
Income (loss) from discontinued operations	135,003	9,681	99,405
Net income (loss)	196,549	(75,868)	96,309
Dividends on preferred shares	(31,616)	(46,438)	(60,353)
Adjustments for redemption/repurchase of preferred shares	(5,932)	(5,730)	(3,796)
Net Income (Loss) Attributable to Noncontrolling Interest	(5,957)	1,891	(744)
Net income (loss) attributable to common shareholders	153,044	(126,145)	31,416
Earnings Per Share, Basic [Abstract]
Continuing operations attributable to common shareholders	$ 0.06	$ (0.52)	$ (0.27)
Discontinued operations attributable to common shareholders	$ 0.41	$ 0.04	$ 0.38
Total	$ 0.47	$ (0.48)	$ 0.11
Earnings Per Share, Diluted [Abstract]
Continuing operations attributable to common shareholders	$ 0.06	$ (0.52)	$ (0.27)
Discontinued operations attributable to common shareholders	$ 0.41	$ 0.04	$ 0.38
Total	$ 0.47	$ (0.48)	$ 0.11
Weighted Average Number of Shares Outstanding, Basic	322,133	267,900	252,694
Weighted Average Number of Shares Outstanding, Diluted	326,712	267,900	259,598
Comprehensive Income (Loss) [Abstract]
Net income (loss)	196,549	(75,868)	96,309
Amortization of interest contracts	451	1,829	1,829
Other	977	(125)	590
Total other comprehensive income	1,428	1,704	2,419
Comprehensive income (loss)	197,977	(74,164)	98,728
Subsidiary of Common Parent [Member]
Revenues:
Rental and related revenue	875,194	771,625	686,242
General contractor and service fee revenue	206,596	275,071	521,796
Revenues, Total	1,081,790	1,046,696	1,208,038
Expenses:
Rental expenses	159,008	137,797	129,717
Real estate taxes	117,747	106,128	95,666
General contractor and other services expenses	183,833	254,870	480,480
Depreciation and amortization	393,450	349,015	305,070
Costs and expenses, total	854,038	847,810	1,010,933
Other Operating Activities
Equity in earnings of unconsolidated companies	54,116	4,674	4,565
Gain on Sale of Properties	59,179	344	68,549
Earnings from sales of land	9,547	0	0
Undeveloped land carrying costs	(8,614)	(8,829)	(8,934)
Impairment charges	(3,777)	0	(12,931)
Other Operating Income (Expense), Net	470	(633)	(1,237)
General and administrative expenses	(42,673)	(46,424)	(43,107)
Other operating transactions, total	68,248	(50,868)	6,905
Operating income (loss)	296,000	148,018	204,010
Other Nonoperating Income (Expense)
Interest and other income, net	1,887	514	658
Interest expense	(228,895)	(229,992)	(206,770)
Gains (Losses) on Extinguishment of Debt	(9,433)	0	0
Acquisition-related activity	(3,093)	(4,192)	(1,188)
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest	56,466	(85,652)	(3,290)
Income Tax Expense (Benefit)	5,080	103	194
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	61,546	(85,549)	(3,096)
Discontinued operations
Income (loss) before gain on sales	1,761	(3,786)	(1,477)
Gain on sale of depreciable properties	133,242	13,467	100,882
Income (loss) from discontinued operations	135,003	9,681	99,405
Net income (loss)	196,549	(75,868)	96,309
Dividends on preferred shares	(31,616)	(46,438)	(60,353)
Adjustments for redemption/repurchase of preferred shares	(5,932)	(5,730)	(3,796)
Noncontrolling Interest in Net Income (Loss) Joint Venture Partners, Nonredeemable	(3,863)	(382)	115
Net income (loss) attributable to common shareholders	155,138	(128,418)	32,275
Earnings Per Share, Basic [Abstract]
Continuing operations attributable to common shareholders	$ 0.06	$ (0.52)	$ (0.27)
Discontinued operations attributable to common shareholders	$ 0.41	$ 0.04	$ 0.38
Total	$ 0.47	$ (0.48)	$ 0.11
Earnings Per Share, Diluted [Abstract]
Continuing operations attributable to common shareholders	$ 0.06	$ (0.52)	$ (0.27)
Discontinued operations attributable to common shareholders	$ 0.41	$ 0.04	$ 0.38
Total	$ 0.47	$ (0.48)	$ 0.11
Weighted Average Number of Shares Outstanding, Basic	326,525	272,729	259,598
Weighted Average Number of Shares Outstanding, Diluted	326,712	272,729	259,598
Comprehensive Income (Loss) [Abstract]
Net income (loss)	196,549	(75,868)	96,309
Amortization of interest contracts	451	1,829	1,829
Other	977	(125)	590
Total other comprehensive income	1,428	1,704	2,419
Comprehensive income (loss)	$ 197,977	$ (74,164)	$ 98,728