Consolidated Statements of Cash Flows (Unaudited) (USD $)	9 Months Ended
	Oct. 31, 2013	Oct. 31, 2012
Net earnings (loss)	$ 94,406,000	$ (15,758,000)
Depreciation and amortization	245,305,000	155,714,000
Amortization of mortgage procurement costs	7,572,000	8,674,000
Impairment of real estate	208,210,000	30,660,000
Impairment of unconsolidated entities	0	390,000
Write-offs of abandoned development projects	27,317,000	14,029,000
Gain on extinguishment of debt	(6,335,000)	(7,288,000)
Net loss on land held for divestiture activity	7,555,000	5,651,000
Net gain on disposition of partial interests in rental properties	(496,092,000)	0
Net gain on change in control of interests	(2,762,000)	(6,766,000)
Deferred income tax expense	60,841,000	30,189,000
Equity in earnings	(59,815,000)	(24,627,000)
Net (gain) loss on land held for divestiture activity of unconsolidated entities	(867,000)	42,170,000
Stock-based compensation expense	8,676,000	7,286,000
Amortization and mark-to-market adjustments of derivative instruments	8,773,000	(6,699,000)
Non-cash interest expense related to Senior Notes	290,000	338,000
Cash distributions from operations of unconsolidated entities	46,338,000	47,095,000
Non-cash operating expenses included in discontinued operations	15,054,000	3,610,000
Gain on disposition included in discontinued operations	(44,342,000)	(28,178,000)
Cost of sales of land included in projects under construction and development and completed rental properties	7,855,000	5,428,000
(Increase) decrease in land held for development and sale	(1,103,000)	3,863,000
Decrease in land held for divestiture	26,000	51,615,000
(Increase) decrease in notes and accounts receivable	(19,274,000)	6,974,000
Decrease in other assets	12,681,000	5,915,000
(Decrease) increase in accounts payable, accrued expenses and other liabilities	(50,340,000)	4,491,000
Net cash provided by operating activities	69,969,000	334,776,000
Cash Flows from Investing Activities
Capital expenditures	(354,458,000)	(686,151,000)
Payment of lease procurement costs	(6,006,000)	(9,986,000)
Increase in notes receivable	(26,922,000)	(26,053,000)
Decrease in restricted cash and escrowed funds used for investing purposes	13,957,000	118,477,000
Proceeds from disposition of rental properties	496,975,000	39,199,000
Decrease (increase) in investments in and advances to unconsolidated entities	42,706,000	(31,811,000)
Net cash provided by (used in) investing activities	166,252,000	(596,325,000)
Cash Flows from Financing Activities
Proceeds from nonrecourse mortgage debt and notes payable	488,207,000	669,927,000
Principal payments on nonrecourse mortgage debt and notes payable	(718,536,000)	(466,360,000)
Borrowings on bank revolving credit facility	772,344,000	356,000,000
Payments on bank revolving credit facility	(697,444,000)	(190,000,000)
Proceeds from issuance of Convertible Senior Notes due 2020, net of $8,750 of issuance costs	291,250,000	0
Redemption of Senior Notes due 2015	(53,253,000)	0
Redemption of Senior Notes due 2017	(132,144,000)	0
Redemption of Senior Notes due 2034	(218,951,000)	0
Make-whole premium and inducements related to exchange of Senior Notes due 2014 for Class A common stock	(5,490,000)	0
Transaction costs related to exchange of Senior Notes due 2014 for Class A common stock	(2,300,000)	0
Deferred financing costs	(9,217,000)	(18,014,000)
Increase in restricted cash and escrowed funds used for financing purposes	0	(8,208,000)
Purchase of treasury stock	(3,167,000)	(1,815,000)
Payment of inducements related to conversion of preferred stock for Class A common stock	0	(13,881,000)
Payment of transaction costs related to conversion of preferred stock for Class A common stock	0	(2,200,000)
Redemption of Series A preferred stock	(5,063,000)	0
Proceeds from equity call hedge related to the issuance of Series A preferred stock	10,231,000	0
Exercise of stock options	1,153,000	1,006,000
Dividends paid to preferred shareholders	(185,000)	(11,550,000)
Acquisitions of noncontrolling interests	(98,687,000)	(21,150,000)
Contribution from redeemable noncontrolling interest	0	11,348,000
Contributions from noncontrolling interests	58,970,000	240,000
Distributions to noncontrolling interests	(29,978,000)	(22,699,000)
Net cash (used in) provided by financing activities	(352,260,000)	282,644,000
Net (decrease) increase in cash and equivalents	(116,039,000)	21,095,000
Cash and equivalents at beginning of period	333,220,000	217,486,000
Cash and equivalents at end of period	217,181,000	238,581,000
Operating Activities
Increase in land held for development and sale	(6,686,000)	(5,534,000)
Decrease (increase) in land held for divestiture	1,661,000	(5,737,000)
Decrease in notes and accounts receivable	1,812,000	9,539,000
Decrease in other assets	75,531,000	2,120,000
Decrease in accounts payable, accrued expenses and other liabilities	(41,221,000)	(10,204,000)
Total effect on operating activities	31,097,000	(9,816,000)
Investing Activities
Decrease in projects under construction and development	45,232,000	10,140,000
Decrease in completed rental properties	836,166,000	90,110,000
Decrease in restricted cash and escrowed funds	4,326,000	16,474,000
(Increase) decrease in investments in and advances to affiliates	(34,671,000)	12,018,000
Total effect on investing activities	851,053,000	128,742,000
Financing Activities
Decrease in nonrecourse mortgage debt and notes payable	(871,068,000)	(124,609,000)
Decrease in senior and subordinated debt	(218,675,000)	(6,049,000)
Decrease in restricted cash and escrowed funds	0	8,208,000
Decrease in preferred stock	(5,489,000)	(133,724,000)
Increase in Class A common stock	4,680,000	2,948,000
Increase in additional paid-in capital	237,199,000	127,042,000
Increase in treasury stock	(12,868,000)	0
(Decrease) increase in redeemable noncontrolling interest	(47,538,000)	6,609,000
Increase in noncontrolling interest	31,609,000	649,000
Total effect on financing activities	$ (882,150,000)	$ (118,926,000)