Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2011
Net earnings (loss)	$ 36,271	$ (568)	$ 85,398
Depreciation and amortization	229,661	208,801	225,082
Amortization of mortgage procurement costs	12,112	11,317	11,000
Impairment of real estate	30,660	235	4,763
Impairment of unconsolidated entities	390	40,284	72,459
Write-off of abandoned development projects	26,850	8,838	9,195
(Gain) loss on extinguishment of debt	(7,096)	(9,590)	21,035
Net (gain) loss on land held for divestiture activity	(6,480)	115,654	0
Net gain on disposition of partial interests in rental properties and other investment	0	(17,665)	(257,990)
Net gain on change in control of interests	(6,766)	0	0
Deferred income tax expense (benefit)	47,590	(53,770)	68,162
Equity in earnings of unconsolidated entities	(85,798)	(21,147)	(42,265)
Net loss on land held for divestiture activity of unconsolidated entities	40,777	41,902	0
Stock-based compensation expense	9,355	7,650	7,969
Amortization and mark-to-market adjustments of derivative instruments	(7,738)	2,279	3,606
Non-cash interest expense related to Senior Notes	489	1,737	1,858
Cash distributions from operations of unconsolidated entities	80,027	59,399	46,802
Cost of sales of land included in projects under construction and development and completed rental properties	5,428	10,820	18,490
Decrease (increase) in land held for development and sale	5,973	(11,860)	(14,973)
Decrease in land held for divestiture	55,650	0	0
(Increase) decrease in notes and accounts receivable	(2,228)	3,575	7,595
Decrease (increase) in other assets	4,888	(11,433)	15,415
Decrease (increase) in restricted cash and escrowed funds used for operating purposes	5,297	(4,354)	(31,701)
Increase (decrease) in accounts payable, accrued expenses and other liabilities	55,328	15,863	(26,899)
Net cash provided by operating activities	422,742	298,763	267,247
Cash Flows from Investing Activities
Capital expenditures	(803,865)	(760,381)	(723,158)
Payment of lease procurement costs	(11,992)	(22,907)	(20,387)
Increase in other assets	(37,583)	(14,489)	(57,226)
Decrease (increase) in restricted cash and escrowed funds used for investing purposes	111,265	90,157	(249,024)
Proceeds from disposition of full or partial interests in rental properties and other investments	113,842	353,243	191,345
Decrease (increase) in investments in and advances to unconsolidated entities	110,630	(85,820)	11,401
Net cash used in investing activities	(517,703)	(440,197)	(847,049)
Cash Flows from Financing Activities
Proceeds from nonrecourse mortgage debt and notes payable	907,608	695,449	658,833
Principal payments on nonrecourse mortgage debt and notes payable	(593,810)	(572,584)	(321,629)
Borrowings on bank revolving credit facility	458,700	464,575	876,052
Payments on bank revolving credit facility	(458,700)	(601,727)	(822,416)
Payment of Puttable Equity-Linked Senior Notes due 2011	0	(39,407)	0
Proceeds from issuance of Convertible Senior Notes due 2018, net of $10,625 of issuance costs	0	339,375	0
Payment of transaction costs related to exchange of Convertible Senior Notes due 2016 for Class A common stock	0	(3,200)	0
Purchase of Senior Notes due 2011 and 2017	0	0	(16,569)
Proceeds received from partial termination of Convertible Senior Notes hedge	0	0	1,869
Payment of deferred financing costs	(25,217)	(14,923)	(36,745)
Change in restricted cash and escrowed funds and book overdrafts	(7,080)	(1,578)	(1,322)
Purchase of treasury stock	(1,963)	(1,670)	(786)
Exercise of stock options	8,368	195	2,621
Payment of inducements related to conversion of preferred stock for Class A common stock	(19,069)	0	0
Payment of transaction costs related to conversion of preferred stock for Class A common stock	(3,301)	0	0
Proceeds from issuance of Series A preferred stock, net of $5,544 of issuance costs	0	0	44,456
Payment for equity call hedge related to the issuance of Series A preferred stock	0	0	(17,556)
Dividends paid to preferred shareholders	(13,060)	(15,400)	(11,807)
Contributions from redeemable noncontrolling interest	11,348	0	181,909
Contributions from noncontrolling interests	1,886	6,087	5,636
Distributions to noncontrolling interests	(27,680)	(89,644)	(20,777)
Acquisitions of noncontrolling interests	(27,335)	0	0
Net cash provided by financing activities	210,695	165,548	521,769
Net increase in cash and equivalents	115,734	24,114	(58,033)
Cash and equivalents at beginning of period	217,486	193,372	251,405
Cash and equivalents at end of period	333,220	217,486	193,372
Operating Activities
Increase in land held for development and sale	(5,906)	(1,399)	(31,599)
Increase in land held for divestiture	(2,944)	0	0
Decrease in notes and accounts receivable	7,937	16,785	22,560
Decrease in other assets	2,465	155,458	80,953
Decrease (increase) in restricted cash and escrowed funds	14,463	149,586	(1,953)
(Decrease) increase in accounts payable, accrued expenses and other liabilities	(34,991)	14,188	(111,940)
Total effect on operating activities	(18,976)	334,618	(41,979)
Investing Activities
Decrease in projects under construction and development	35,367	429,690	32,816
Decrease in completed rental properties	170,033	1,230,710	667,495
Decrease (increase) in investments in and advances to affiliates	21,826	(298,492)	111,644
Total effect on investing activities	227,226	1,361,908	811,955
Financing Activities
Decrease in nonrecourse mortgage debt and notes payable	(215,008)	(1,648,245)	(776,588)
Decrease in senior and subordinated debt	(6,049)	(40,000)	(277,658)
Decrease in restricted cash and escrowed funds	8,208	0	0
(Decrease) increase in preferred stock	(209,448)	0	170,000
Increase in Class A common stock	4,617	959	2,636
Increase in additional paid-in capital	200,448	36,904	102,939
Increase in redeemable noncontrolling interest	8,424	6,887	46,845
Increase (decrease) in noncontrolling interest	558	(53,031)	(38,150)
Total effect on financing activities	(208,250)	(1,696,526)	(769,976)
Segment, Discontinued Operations [Member]
Depreciation and amortization	6,159	14,139	22,935
Amortization of mortgage procurement costs	243	1,257	2,611
Impairment of real estate	4,254	13,692	81,643
(Gain) loss on extinguishment of debt	464	0	0
Deferred income tax expense (benefit)	(18,118)	5,262	(13,640)
Gain on disposition of rental properties	$ (100,900)	$ (133,554)	$ (51,303)