Consolidated Statements of Cash Flows (Unaudited) (USD $)	9 Months Ended
	Oct. 31, 2011		Oct. 31, 2010
Cash Flows from Operating Activities
Net earnings	$ 103,772,000		$ 82,408,000
Depreciation and amortization	166,660,000		177,733,000
Amortization of mortgage procurement costs	9,036,000		8,655,000
Impairment of real estate	15,777,000		6,803,000
Impairment of unconsolidated entities	41,289,000		36,745,000
Write-off of abandoned development projects	9,931,000		678,000
Gain on extinguishment of debt	(9,334,000)		(10,653,000)
Net gain on disposition of partial interests in rental properties and other investment	(15,410,000)		(257,990,000)
Deferred income tax expense (benefit)	(6,720,000)		87,586,000
Equity in earnings of unconsolidated entities	(23,652,000)		(19,293,000)
Stock-based compensation expense	6,070,000		6,279,000
Amortization and mark-to-market adjustments of derivative instruments	3,320,000		10,145,000
Non-cash interest expense related to Puttable Equity-Linked Senior Notes	1,655,000		1,419,000
Cash distributions from operations of unconsolidated entities	37,747,000		29,755,000
Cost of sales of land included in projects under construction and development and completed rental properties	3,868,000		17,359,000
Increase in land held for development or sale	(18,370,000)		(12,591,000)
Decrease in notes and accounts receivable	7,036,000		17,283,000
(Increase) decrease in other assets	(5,625,000)		7,069,000
Increase in restricted cash and escrowed funds used for operating purposes	(10,585,000)		(40,641,000)
Decrease in accounts payable, accrued expenses and other liabilities	(8,813,000)		(55,166,000)
Net cash provided by operating activities	203,470,000		149,462,000
Cash Flows from Investing Activities
Capital expenditures	(547,531,000)		(563,880,000)
Payment of lease procurement costs	(16,907,000)		(16,024,000)
Increase in other assets	(10,215,000)		(40,597,000)
Decrease (increase) in restricted cash and escrowed funds used for investing purposes	181,609,000		(301,856,000)
Proceeds from dispositions of full or partial interests in rental properties	319,461,000		189,788,000
(Increase) decrease in investments in and advances to affiliates	(90,210,000)		13,677,000
Net cash used in investing activities	(163,793,000)		(718,892,000)
Cash Flows from Financing Activities
Proceeds from nonrecourse mortgage debt and notes payable	265,836,000		599,495,000
Principal payments on nonrecourse mortgage debt and notes payable	(317,206,000)		(279,769,000)
Borrowings on bank revolving credit facility	464,575,000		661,352,000
Payments on bank revolving credit facility	(601,727,000)		(619,266,000)
Payment of Puttable Equity-Linked Senior Notes due 2011	(39,407,000)
Proceeds from issuance of Convertible Senior Notes due 2018, net of $10,625 of issuance costs	339,375,000
Payment of transaction costs related to exchanges of Convertible Senior Notes due 2016 for Class A common stock	(3,200,000)
Purchase of Senior Notes due 2011 and 2017	0		(16,569,000)
Payment of deferred financing costs	(12,414,000)		(25,155,000)
Change in restricted cash and escrowed funds and book overdrafts	(1,681,000)		(1,187,000)
Proceeds from issuance of Series A preferred stock, net of $5,544 of issuance costs	0		44,456,000
Payment for equity call hedge related to the issuance of Series A preferred stock	0		(17,556,000)
Dividends paid to preferred shareholders	(11,550,000)		(7,957,000)
Purchase of treasury stock	(1,670,000)		(711,000)
Exercise of stock options	177,000
Contributions from redeemable noncontrolling interest	0		181,909,000
Contributions from noncontrolling interests	3,087,000		2,526,000
Distributions to noncontrolling interests	(87,588,000)		(13,303,000)
Net cash (used in) provided by financing activities	(3,393,000)		508,265,000
Net increase (decrease) in cash and equivalents	36,284,000		(61,165,000)
Cash and equivalents at beginning of period	193,372,000		251,405,000
Cash and equivalents at end of period	229,656,000		190,240,000
Operating Activities
Increase in land held for development or sale	(11,155,000)	[1],[2],[3]	(16,631,000)	[1],[2]
Decrease in notes and accounts receivable	26,969,000	[4],[5]	18,234,000	[4],[6],[7],[8]
Decrease in other assets	150,699,000	[4],[5],[6],[9]	71,672,000	[4],[6],[7]
Decrease (increase) in restricted cash and escrowed funds	149,593,000	[4],[5]	(1,106,000)	[4],[7]
Decrease in accounts payable, accrued expenses and other liabilities	(4,235,000)	[2],[4],[5],[6]	(115,435,000)	[2],[4],[7]
Total effect on operating activities	311,871,000		(43,266,000)
Investing Activities
Decrease in projects under construction and development	442,332,000	[1],[10],[2],[5]	32,714,000	[1],[10],[2],[7]
Decrease in completed rental properties	1,212,542,000	[1],[4],[5],[6]	567,227,000	[1],[4],[6],[7]
(Increase) decrease in investments in and advances to unconsolidated entities	(275,880,000)	[4],[5]	108,974,000	[11],[4],[7]
Total effect on investing activities	1,378,994,000		708,915,000
Financing Activities
Decrease in nonrecourse mortgage debt and notes payable	(1,642,048,000)	[12],[3],[4],[5],[6]	(661,185,000)	[11],[4],[6],[7]
Decrease in senior and subordinated debt	(40,000,000)	[9]	(167,658,000)	[13]
Increase in preferred stock			170,000,000	[13]
Increase in Class A common stock	959,000	[9]
Increase (decrease) in additional paid-in capital	37,956,000	[10],[11],[12],[9]	(2,080,000)	[10],[11],[13]
Increase in redeemable noncontrolling interest	4,808,000	[11]	44,842,000	[11]
Decrease in noncontrolling interest	(52,540,000)	[12],[4],[5]	(49,568,000)	[4],[7],[8]
Total effect on financing activities	(1,690,865,000)		(665,649,000)
Segment Discontinued Operations [Member]
Cash Flows from Operating Activities
Depreciation and amortization	2,216,000		8,707,000
Amortization of mortgage procurement costs	739,000		1,531,000
Impairment of real estate	0		79,603,000
Deferred income tax expense (benefit)	14,558,000		(29,186,000)
Gain on disposition of rental properties	$ (121,695,000)		$ (4,776,000)

[1] Commercial Group and Residential Group outlots reclassified prior to sale from projects under construction and development or completed rental properties to land held for sale.

[2] Increase or decrease in construction payables included in accounts payable, accured expenses and other liabilities.

[3] Assumption of debt in exchange for a 75% equity interest in a land development project during the nine months ended October 31, 2011.

[4] Disposition of partial interests in Mall at Stonecrest, a regional mall, and 15 New York retail properties and change to equity method of accounting for remaining ownership interest during the nine months ended October 31, 2011 and disposition of partial interests in the Company's mixed-use University Park project and in The Grand, Lenox Club and Lenox Park apartment communities and change to equity method of accounting for the remaning ownership interest during the nine months ended October 31, 2010.

[5] Change to equity method of accounting from full consolidation for 8 Spruce Street and DKLB BKLN apartment buildings, due to recapitalization transactions during the nine months ended October 31, 2011.

[6] Disposition of Waterfront Station East 4th & West 4th Buildings, office buildings, and Charleston Marriott, a hotel, including assumption of nonrecourse mortgage debt by the buyers, during the nine months ended October 31, 2011 and disposition of Saddle Rock Village, a specialty retail center, and 101 San Fernando, an apartment community, during the nine months ended October 31, 2010.

[7] Change in consolidation method of accounting for various entities in the Residential and Commercial Groups during the nine months ended October 31, 2010, due to the adoption of accounting guidance for the consolidation of variable interest entities.

[8] Receipt of a note receivable as a contribution from a noncontrolling interest during the nine months ended October 31, 2010.

[9] Exchange of a portion of the Company's senior notes due 2016 for Class A common stock during the nine months ended October 31, 2011.

[10] Capitalization of stock-based compensation granted to employees directly involved with the acquisition, development and construction of real estate.

[11] Conversion of loans into investments in and advances to unconsolidated entities and redeemable noncontrolling interest in accordance with the amended operating agreement of Nets Sports and Entertainment, LLC, concurrent with the Company's closing on the purchase agreement with entities controlled by Mikhail Prokhorov during the nine months ended October 31, 2010 and adjustments to redemption value of redeemable noncontrolling interest during the nine months ended October 31, 2011.

[12] Difference between fair value of consideration transferred and the book value of noncontrolling interest in connection with the acquisition of certain partners' noncontrolling interests in Nets Sports and Entertaintment, LLC and development projects in the Commercial Group during the nine months ended October 31, 2011.

[13] Exchange of a portion of the Company's senior notes due 2011, 2015 and 2017 for a new issue of 7.0% Series A Cumulative Perpetual Convertible Preferred Stock during the nine months ended October 31, 2010.