CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Statement of Cash Flows [Abstract]
Net cash provided by operating activities:	$ 181,475	$ 165,547
Cash flows from investing activities:
Acquisition of real estate, including intangible assets	(197,926)	(51,962)
Investment in real estate under construction	(94,287)	(106,502)
Capital expenditures	(18,744)	(9,434)
Net proceeds from sale of properties	156,475	85,115
Principal payments received on loans receivable	4,334	11,496
Investment in loans receivable	(10,267)	(40,248)
Investments in non-consolidated entities	(10,322)	0
Distributions from non-consolidated entities in excess of accumulated earnings	1,171	879
Increase in deferred leasing costs	(4,242)	(8,414)
Change in escrow deposits and restricted cash	3,596	(42,579)
Real estate deposits, net	(2,634)	1,332
Net cash used in investing activities	(172,846)	(160,317)
Cash flows from financing activities:
Dividends to common and preferred shareholders	(123,529)	(118,840)
Retirement of convertible notes	(529)	(62)
Principal amortization payments	(26,760)	(28,303)
Principal payments on debt, excluding normal amortization	(106,956)	(163,267)
Change in credit facility borrowings, net	73,000	(48,000)
Proceeds from senior notes	0	249,708
Proceeds from term loans	0	99,000
Increase in deferred financing costs	(7,339)	(3,402)
Proceeds of mortgages and notes payable	80,843	27,790
Change in restricted cash	(1,573)	0
Cash distributions to noncontrolling interests	(2,865)	(2,881)
Purchase of noncontrolling interest	(4,022)	(2,100)
Redemption of noncontrolling interests	0	(1,962)
Issuance of common shares, net	17,312	19,165
Repurchase of common shares	(11,019)	0
Net cash provided by (used in) financing activities	(113,437)	26,846
Change in cash and cash equivalents	(104,808)	32,076
Cash and cash equivalents, at beginning of period	191,077	77,261
Cash and cash equivalents, at end of period	$ 86,269	$ 109,337