CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:
Net income	$ 454,889	$ 361,775	$ 363,261
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization (including amounts in discontinued operations)	769,881	764,775	459,704
Amortization of deferred revenue and lease intangibles, net	(15,793)	(17,118)	(12,159)
Other non-cash amortization	(16,745)	(39,943)	(13,163)
Stock-based compensation	20,653	20,784	19,346
Straight-lining of rental income, net	(30,540)	(24,042)	(14,885)
Loss on extinguishment of debt, net	1,048	37,640	27,604
Gain on real estate dispositions, net (including amounts in discontinued operations)	(3,617)	(80,952)	0
Gain on real estate loan investments	(5,056)	(5,230)	(3,255)
Gain on sale of marketable securities	(856)	0	(733)
Income tax benefit (including amounts in discontinued operations)	(11,828)	(6,286)	(31,137)
Loss (income) from unconsolidated entities	1,748	(1,509)	52
Gain on re-measurement of equity interest upon acquisition, net	(1,241)	(16,645)	0
Other	8,407	10,414	7,405
Changes in operating assets and liabilities:
(Increase) decrease in other assets	(690)	3,756	424
Increase (decrease) in accrued interest	6,806	9,969	(9,150)
Decrease (increase) in accounts payable and other liabilities	17,689	(24,572)	(20,117)
Net cash provided by operating activities	1,194,755	992,816	773,197
Cash flows from investing activities:
Net investment in real estate property	(1,437,002)	(1,453,065)	(531,605)
Purchase of private investment funds	0	(276,419)	0
Purchase of noncontrolling interest	(14,331)	(3,934)	(3,319)
Investment in loans receivable and other	(37,963)	(452,558)	(628,133)
Proceeds from real estate disposals	35,591	149,045	20,618
Proceeds from loans receivable	325,518	43,219	220,179
Proceeds from sale or maturity of marketable securities	5,493	37,500	23,050
Funds held in escrow for future development expenditures	19,458	(28,050)	0
Development project expenditures	(95,741)	(114,002)	(47,591)
Capital expenditures	(81,614)	(69,430)	(50,473)
Other	(2,169)	(1,995)	(165)
Net cash used in investing activities	(1,282,760)	(2,169,689)	(997,439)
Cash flows from financing activities:
Net change in borrowings under credit facilities	(164,029)	84,938	537,452
Proceeds from debt	2,767,546	2,710,405	1,343,640
Repayment of debt	(1,792,492)	(1,193,023)	(1,388,962)
Payment of deferred financing costs	(31,277)	(23,770)	(20,040)
Issuance of common stock, net	141,343	342,469	299,847
Cash distribution to common stockholders	(802,123)	(728,546)	(521,046)
Cash distribution to redeemable OP unitholders	(5,040)	(4,446)	(2,359)
Purchases of redeemable OP units	(659)	(4,601)	(185)
Contributions from noncontrolling interest	2,395	38	2
Distributions to noncontrolling interest	(9,286)	(5,215)	(2,556)
Other	8,618	20,665	2,489
Net cash provided by financing activities	114,996	1,198,914	248,282
Net increase in cash and cash equivalents	26,991	22,041	24,040
Effect of foreign currency translation on cash and cash equivalents	(83)	60	(45)
Cash and cash equivalents at beginning of period	67,908	45,807	21,812
Cash and cash equivalents at end of period	94,816	67,908	45,807
Supplemental disclosure of cash flow information:
Interest paid including swap payments and receipts	338,311	329,655	257,175
Assets and liabilities assumed from acquisitions:
Real Estate Investments	223,955	582,694	10,973,093
Utilization of funds held for an Internal Revenue Code Section 1031 exchange	0	(134,003)	0
Other Assets Acquired	6,635	77,730	594,176
Debt assumed	183,848	412,825	3,651,089
Other Liabilities Assumed	29,868	70,391	952,279
Deferred income tax liability	5,181	4,299	43,889
Redeemable OP unitholder interests	0	0	100,888
Noncontrolling interests	11,693	34,580	81,192
Equity issued	0	4,326	6,737,932
Debt Transferred on the Sale of Assets	$ 0	$ 14,535	$ 0