Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Statement of Cash Flows [Abstract]
Net income	$ 56,904	$ (11,354)
Adjustments to reconcile net loss to net cash provided by operating activities:
Gain on sale of investment properties, including discontinued operations	57,272	143
Loss on extinguishment of debt	0	94
Impairment loss included in discontinued operations	0	12,233
Depreciation and amortization, including discontinued operations	12,299	14,256
Amortization of deferred financing costs	279	235
Amortization of stock options and restricted stock, net of forfeitures	361	583
Effect of certain non-cash adjustments to rental revenues	(1,806)	(1,482)
Income from unconsolidated joint ventures	(1,652)	(2,186)
Operating distributions from unconsolidated joint ventures	1,417	1,550
Land and multi-family cost of sales, net of closing costs paid	904	538
Changes in other operating assets and liabilities:
Change in other receivables and other assets, net	(1,581)	(306)
Change in operating liabilities	(8,083)	(3,796)
Net cash provided by operating activities	1,770	10,222
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from investment property sales	112,651	0
Property acquisition, development and tenant asset expenditures	(295,789)	(8,039)
Investment in unconsolidated joint ventures	(19)	(4,483)
Distributions from unconsolidated joint ventures	39,563	24,098
Collection of notes receivable	339	212
Change in notes receivable and other assets	(1,221)	(1,176)
Change in restricted cash	(764)	807
Net cash provided by (used in) investing activities	(145,240)	11,419
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from credit facility	102,000	239,500
Repayment of credit facility	(47,000)	(350,750)
Proceeds from other notes payable	1,166	102,191
Repayment of notes payable	(75,139)	(1,215)
Payment of loan issuance costs	0	(3,353)
Common dividends paid	(4,689)	(4,687)
Preferred dividends paid	(3,227)	(3,227)
Distributions to noncontrolling interests	(491)	(956)
Net cash used in financing activities	(27,380)	(22,497)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(170,850)	(856)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	176,892	4,858
CASH AND CASH EQUIVALENTS AT END OF PERIOD	6,042	4,002
INTEREST PAID, NET OF AMOUNTS CAPITALIZED	$ 5,470	$ 6,606