Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Net loss	$ (57,038,000)	$ (87,514,000)
Depreciation and amortization	206,782,000	169,838,000
Amortization of mortgage procurement costs	5,756,000	5,967,000
Impairment of real estate	425,463,000	130,795,000
Impairment	1,384,000	0
Write-offs of abandoned development projects	674,000	283,000
Loss on extinguishment of debt	61,953,000	927,000
Net loss on disposition of partial interest in development project	0	19,590,000
Net (gain) loss on disposition of full or partial interest in rental properties	(1,746,000)	613,000
Net gain on change in control of interests	(487,684,000)	(2,759,000)
Deferred income tax benefit	(6,651,000)	(52,373,000)
Earnings from unconsolidated entities	(199,000)	(80,543,000)
Stock-based compensation expense	16,569,000	10,730,000
Amortization and mark-to-market adjustments of derivative instruments	(2,653,000)	4,984,000
Cash distributions from operations of unconsolidated entities	46,671,000	59,217,000
Non-cash operating expenses and deferred taxes included in discontinued operations	0	9,883,000
Gain on disposition of rental properties included in discontinued operations	0	(28,100,000)
Decrease in land inventory	5,062,000	9,203,000
Increase in notes and accounts receivable	(17,726,000)	(2,065,000)
(Increase) decrease in other assets	(15,341,000)	7,562,000
Decrease in accounts payable, accrued expenses and other liabilities	(22,726,000)	(15,009,000)
Net cash provided by operating activities	158,550,000	161,229,000
Cash Flows from Investing Activities
Capital expenditures	(338,490,000)	(295,182,000)
Acquisitions	(397,275,000)	(19,988,000)
Payment of lease procurement costs	(8,063,000)	(7,212,000)
(Increase) decrease in notes receivable	(10,934,000)	10,580,000
Decrease in restricted cash used for investing purposes	42,262,000	106,165,000
Proceeds from disposition of rental properties or development project	36,594,000	236,908,000
Contributions to investments in and advances to unconsolidated entities	(92,678,000)	(112,613,000)
Distributions from investments in and advances to unconsolidated entities	11,911,000	120,294,000
Net cash (used in) provided by investing activities	(756,673,000)	38,952,000
Cash Flows from Financing Activities
Proceeds from nonrecourse mortgage debt and notes payable	256,049,000	507,788,000
Principal payments on nonrecourse mortgage debt and notes payable	(441,822,000)	(733,937,000)
Borrowings on revolving credit facility	111,850,000	832,325,000
Payments on revolving credit facility	(111,850,000)	(832,325,000)
Payments to noteholders related to exchange of convertible senior notes	(61,110,000)	0
Transaction costs related to exchange of convertible senior notes	(6,950,000)	0
Proceeds received from termination of convertible senior note hedge	17,818,000	0
Proceeds from issuance of Class A common stock, net of $34,438 of transaction costs	806,500,000	0
Payments of deferred financing costs	(11,447,000)	(10,751,000)
Purchase of treasury stock	(5,412,000)	(3,800,000)
Exercise of stock options	955,000	583,000
Acquisitions of noncontrolling interests	(308,000)	(83,871,000)
Contributions from noncontrolling interests	77,369,000	34,249,000
Distributions to noncontrolling interests	(28,588,000)	(8,992,000)
Net cash provided by (used in) financing activities	603,054,000	(298,731,000)
Net increase (decrease) in cash and equivalents	4,931,000	(98,550,000)
Cash and equivalents at beginning of period	326,518,000	280,206,000
Cash and equivalents at end of period	$ 331,449,000	$ 181,656,000