Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Statement of Cash Flows [Abstract]
Net income	$ 29,160	$ 122,763
Adjustments to reconcile net loss to net cash provided by operating activities:
Gain on sale of investment properties, including discontinued operations	20,941	69,911
Depreciation and amortization, including discontinued operations	102,481	45,950
Amortization of deferred financing costs	604	778
Net amortization of stock options and restricted stock	1,508	1,421
Effect of certain non-cash adjustments to rental revenues	(21,740)	(5,605)
Income Loss from Unconsolidated Joint Ventures	5,343	65,862
Operating distributions from unconsolidated joint ventures	5,195	65,563
Land and multi-family cost of sales, net of closing costs paid	302	904
Changes in other operating assets and liabilities:
Change in other receivables and other assets, net	(1,912)	(3,572)
Change in operating liabilities	5,282	6,247
Net cash provided by operating activities	94,596	98,676
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from investment property sales	53,827	171,779
Property acquisition, development, and tenant asset expenditures	(351,657)	(1,502,016)
Investment in unconsolidated joint ventures	(10,578)	(2,139)
Distributions from unconsolidated joint ventures	7,433	86,752
Collection of notes receivable	1,020	1,233
Change in notes receivable and other assets	(2,838)	(1,930)
Change in restricted cash	(1,834)	(101)
Net cash used in investing activities	(304,627)	(1,246,422)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from credit facility	395,175	343,725
Repayment of credit facility	(347,550)	(292,650)
Proceeds from other notes payable	68	304,268
Repayment of notes payable	(6,713)	(76,314)
Payments of Financing Costs	3,176	1,693
Proceeds from Issuance of Common Stock	321,912	826,529
Preferred Stock Redemption	(94,775)	(74,827)
Common dividends paid	(45,351)	(18,657)
Preferred dividends paid	(2,955)	(8,231)
Distributions to noncontrolling interests	(369)	(25,888)
Net cash provided by financing activities	216,266	976,262
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	6,235	(171,484)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	975	176,892
CASH AND CASH EQUIVALENTS AT END OF PERIOD	7,210	5,408
Interest paid, net of amounts capitalized	20,450	14,522
Accrued property acquisition, development, and tenant asset expenditures	3,055	14,764
Transfer from operating properties to operating properties and related assets held for sale	181,116	49,435
Transfer from projects under development to operating properties	0	25,629
Transfer from other assets to projects under development	$ 0	$ 3,062