CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Net cash provided by operating activities:	$ 120,453	$ 118,842
Cash flows from investing activities:
Acquisition of real estate, including intangible assets	(23,000)	(13,533)
Investment in real estate under construction	(77,931)	(59,726)
Capital expenditures	(34,693)	(23,924)
Acquisition of remaining interest in NLS	(9,438)	0
Net proceeds from sale of properties	139,876	101,971
Principal payments received on loans receivable	3,206	27,003
Investment in loans receivable	(8,001)	(32,553)
Investments in non-consolidated entities	(1,963)	(19,940)
Distributions from non-consolidated entities in excess of accumulated earnings	351	140
Sale of interest in non-consolidated entity	7,000	0
Increase in deferred leasing costs	(8,754)	(10,999)
Change in escrow deposits and restricted cash	3,892	(4,508)
Real estate deposits	(49)	(410)
Net cash used in investing activities	(9,504)	(36,479)
Cash flows from financing activities:
Dividends to common and preferred shareholders	(75,399)	(70,512)
Repurchase of exchangeable notes	(62,150)	0
Principal amortization payments	(25,540)	(26,146)
Principal payments on debt, excluding normal amortization	(214,358)	(70,956)
Change in revolving credit facility borrowings, net	93,000	0
Proceeds from term loan	215,000	0
Increase in deferred financing costs	(4,683)	(4,214)
Proceeds of mortgages and notes payable	61,500	15,000
Cash distributions to noncontrolling interests	(34,418)	(3,906)
Contributions from noncontrolling interests	889	0
Repurchase of preferred shares	(70,000)	(1,431)
Receipts on forward equity commitment, net	0	1,285
Exercise of employee common share options	44	777
Issuance of common shares, net	5,772	96,595
Net cash used in financing activities	(110,343)	(63,508)
Cash acquired in acquisition of remaining interest in NLS	8,107	0
Change in cash and cash equivalents	8,713	18,855
Cash and cash equivalents, at beginning of period	63,711	52,644
Cash and cash equivalents, at end of period	$ 72,424	$ 71,499