Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities:
Net income	$ 192,539	$ 209,281
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	259,566	297,979
Amortization of above and below market leases, net	(359)	(2,234)
Amortization of debt premiums, discounts and financing costs	10,118	11,475
Straight-line rental income	(3,115)	(7,073)
Provision for asset impairment	80,281	229,486
Gain (loss) on sale of property, net	171,148	414,923
(Gain) loss on extinguishment of debt	(1,930)	18,984
Equity in earnings of unconsolidated entities	(334)	(11,044)
Distributions from unconsolidated entities	6,206	4,363
(Gain), loss and impairment of investment in unconsolidated entities, net	(4,509)	6,039
Realized gain on sale of marketable securities	(42,998)	(31,866)
Changes in assets and liabilities:
Accounts and rents receivable	(11,357)	(10,157)
Deferred costs and other assets	(2,375)	12,272
Accounts payable and accrued expenses	25,712	21,622
Other liabilities	(11,960)	(8,549)
Net cash flows provided by operating activities	324,337	325,655
Cash flows from investing activities:
Purchase of investment properties	(194,900)	(783,594)
Acquired in-place and market lease intangibles, net	(14,797)	(11,609)
Payments to acquire goodwill	0	(10,918)
Capital expenditures and tenant improvements	(41,124)	(48,691)
Investment in development projects	(73,470)	(35,823)
Proceeds from sale of investment properties, net	774,634	1,884,538
Purchase of marketable securities	0	(3,686)
Proceeds from sale of marketable securities	117,170	95,741
Consolidation of equity method investment	(2,944)	0
Payments to Acquire Equity Method Investments	(38,909)	(5,275)
Distributions from unconsolidated entities	26,569	15,315
Proceeds and Return of Capital From The Sale Of Unconsolidated Entities	20,047	29,622
Payment of leasing fees	(3,055)	(3,970)
Proceeds from Collection of Notes Receivable	4	1,632
Increase (Decrease) in Restricted Cash	(21,650)	(10,792)
Payments for (Proceeds from) Productive Assets	12,565	(19,948)
Net cash flows provided by investing activities	560,140	1,092,542
Cash flows from financing activities:
Proceeds from Issuance of Common Stock, Dividend Reinvestment Plan	95,832	136,619
Shares repurchased	(403,911)	(28,010)
Distributions paid	(331,147)	(335,993)
Proceeds from debt and notes payable	297,515	656,805
Payoffs of debt	(367,479)	(1,561,408)
Principal payments of mortgage debt	(31,266)	(38,168)
Payoff of margin securities debt, net	(59,681)	(65,354)
Payments for Repurchase of Other Equity	(47,762)	0
Payment of loan fees and deposits	(636)	(9,649)
Proceeds from Noncontrolling Interests	1,518	0
Payments of Ordinary Dividends, Noncontrolling Interest	(16)	(16)
Payments for contingent consideration	(7,891)	(10,000)
Net cash flows used in financing activities	(854,924)	(1,255,174)
Net increase in cash and cash equivalents	29,553	163,023
Cash and cash equivalents, at beginning of period	319,237	220,779
Cash and cash equivalents, at end of period	348,790	383,802
Supplemental disclosure of cash flow information:
Noncash or Part Noncash Acquisition, Investments Acquired	(194,900)	(819,837)
Tenant and real estate tax liabilities assumed at acquisition, net	0	(552)
Assumption of mortgage debt at acquisition	0	(35,963)
Non-cash discount of mortgage debt assumed	0	702
Noncash or Part Noncash Acquisition, Restricted Cash Acquired	0	(974)
Supplemental cash flow, total	(194,900)	(783,594)
Cash paid for interest, net capitalized interest of $3,022 and $5,924	159,193	209,235
Supplemental schedule of non-cash investing and financing activities:
Property surrendered in extinguishment of debt	11,000	5,289
Mortgages Assumed by Buyer Upon Disposition of Property	657,339	7,683
Real Estate Owned, Properties Contributed to an Unconsolidated Entity, Net of Related Payables	0	99,092
Consolidation of assets from equity method investment	21,833	0
Noncash or Part Noncash Acquisition, Debt Assumed at Consolidation of Joint Venture	11,967	0
Noncash or part noncash acquisition, consolidation of ciabilities assumed from equity method investment	$ 446	$ 0