CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Cash Flows [Abstract]
Net cash provided by operating activities:	$ 59,221	$ 57,921
Cash flows from investing activities:
Acquisition of real estate, including intangible assets	(27,197)	(197,275)
Investment in real estate under construction	(20,812)	(30,778)
Capital expenditures	(1,325)	(1,717)
Net proceeds from sale of properties	57,898	4,433
Principal payments received on loans receivable	70	64
Investment in loans receivable	0	(83)
Investments in non-consolidated entities	(14,977)	(3,032)
Distributions from non-consolidated entities in excess of accumulated earnings	6,850	221
Increase in deferred leasing costs	(1,230)	(1,420)
Change in escrow deposits and restricted cash	(32,193)	(1,540)
Real estate deposits, net	(65)	(1,999)
Net cash used in investing activities	(32,981)	(233,126)
Cash flows from financing activities:
Dividends to common and preferred shareholders	(41,182)	(41,045)
Principal amortization payments	(7,120)	(13,867)
Principal payments on debt, excluding normal amortization	(8,130)	(83,320)
Change in revolving credit facility borrowings, net	(30,000)	93,000
Payment of developer liabilities	(3,851)	0
Change in deferred financing costs	99	(2,444)
Proceeds of mortgages and notes payable	57,500	80,843
Cash distributions to noncontrolling interests	(689)	(800)
Issuance of common shares, net	3,751	6,582
Repurchase of common shares	(8,973)	0
Net cash provided by (used in) financing activities	(38,595)	38,949
Change in cash and cash equivalents	(12,355)	(136,256)
Cash and cash equivalents, at beginning of period	93,249	191,077
Cash and cash equivalents, at end of period	$ 80,894	$ 54,821