CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities:
Net income	$ 233,784	$ 196,564
Depreciation and amortization of real estate, in-place lease and other intangibles:
Continuing operations	104,717	85,280
Discontinued operations		2,996
Amortization of above and below market lease intangibles, net	(78)	(697)
Amortization of deferred compensation	5,430	5,373
Amortization of deferred financing costs, net	4,644	4,529
Straight-line rents	(18,793)	(9,927)
Loan and direct financing lease interest accretion	(24,266)	(25,878)
Deferred rental revenues	1,257	1,839
Equity income from unconsolidated joint ventures	(14,801)	(13,675)
Distributions of earnings from unconsolidated joint ventures	803	913
Gain on sales of real estate		(2,856)
Marketable securities gains, net	(10,977)
Derivative (gains) losses, net	(105)	203
Changes in:
Accounts receivable, net	1,967	2,300
Other assets	(8,699)	(7,877)
Accounts payable and accrued liabilities	(60,533)	(52,619)
Net cash provided by operating activities	214,350	186,468
Cash flows from investing activities:
Acquisitions of real estate	(25,654)
Development of real estate	(38,749)	(22,340)
Leasing costs and tenant and capital improvements	(8,959)	(8,931)
Proceeds from sales of real estate, net		7,238
Distributions in excess of earnings from unconsolidated joint ventures	568	2,716
Proceeds from the sale of marketable securities	28,030
Principal repayments on loans receivable	2,188	4,015
Investments in loans receivable	(14,957)	(9,939)
(Increase) decrease in restricted cash	173	(3,905)
Net cash used in investing activities	(57,360)	(31,146)
Cash flows from financing activities:
Net borrowings (repayments) under bank line of credit	14,000	(454,000)
Issuance of senior unsecured notes		450,000
Repayment of senior unsecured notes	(150,000)
Repayments of mortgage debt	(12,135)	(10,057)
Deferred financing costs		(10,117)
Net proceeds from the issuance of common stock and exercise of options	32,253	397,569
Dividends paid on common and preferred stock	(238,467)	(211,067)
Issuance of noncontrolling interests	987	181
Distributions to noncontrolling interests	(3,754)	(3,912)
Net cash provided by (used in) financing activities	(357,116)	158,597
Net increase (decrease) in cash and cash equivalents	(200,126)	313,919
Cash and cash equivalents, beginning of period	247,673	33,506
Cash and cash equivalents, end of period	$ 47,547	$ 347,425