Consolidated Statements of Cash Flows (Unaudited) (USD $)	3 Months Ended
	Apr. 30, 2013	Apr. 30, 2012
Net earnings (loss)	$ (19,074,000)	$ 23,773,000
Depreciation and amortization	69,495,000	50,474,000
Amortization of mortgage procurement costs	2,688,000	2,756,000
Write-offs of abandoned development projects	81,000	447,000
Loss on extinguishment of debt	5,238,000	719,000
Impairment of real estate	0
Net gain on land held for divestiture activity	(452,000)	0
Deferred income tax expense (benefit)	(14,870,000)	9,572,000
Equity in earnings of unconsolidated entities	(5,850,000)	(3,773,000)
Net loss on land held for divestiture activity of unconsolidated entities	147,000	0
Stock-based compensation expense	3,434,000	2,528,000
Amortization and mark-to-market adjustments of derivative instruments	2,801,000	(3,133,000)
Non-cash interest expense related to Senior Notes	133,000	81,000
Cash distributions from operations of unconsolidated entities	11,407,000	16,014,000
Gain on disposition of rental properties	5,608,000	3,052,000
Cost of sales of land included in projects under construction and development and completed rental properties	4,974,000	2,825,000
Increase in land held for development and sale	(5,694,000)	(5,337,000)
Increase in land held for divestiture	(188,000)	0
(Increase) decrease in notes and accounts receivable	(15,482,000)	22,527,000
Decrease in other assets	6,968,000	4,098,000
Increase in accounts payable, accrued expenses and other liabilities	(12,606,000)	(42,338,000)
Net cash provided by operating activities	16,330,000	78,098,000
Cash Flows from Investing Activities
Capital expenditures	(120,390,000)	(196,354,000)
Payment of lease procurement costs	(2,350,000)	(2,049,000)
(Increase) decrease in other assets	(8,686,000)	4,662,000
(Increase) decrease in restricted cash and escrowed funds used for investing purposes	(2,105,000)	157,402,000
Proceeds from disposition of rental properties	22,399,000	8,642,000
Decrease (increase) in investments in and advances to unconsolidated entities	23,539,000	(21,645,000)
Net cash used in investing activities	(87,593,000)	(49,342,000)
Cash Flows from Financing Activities
Proceeds from nonrecourse mortgage debt and notes payable	70,450,000	210,957,000
Principal payments on nonrecourse mortgage debt and notes payable	(63,320,000)	(157,733,000)
Borrowings on bank revolving credit facility	88,450,000	75,000,000
Payments on bank revolving credit facility	(43,450,000)	(75,000,000)
Payment of inducements related to exchange of Senior Notes due 2014 for Class A common stock	(4,762,000)	0
Payment of transaction costs related to exchange of Senior Notes due 2014 for Class A common stock	(2,300,000)	0
Payment of Senior Notes due 2015	(53,253,000)	0
Payment of deferred financing costs	(5,541,000)	(4,132,000)
Purchase of treasury stock	(3,167,000)	(1,182,000)
Exercise of stock options	1,042,000	6,000
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
Dividends paid to preferred shareholders	(185,000)	(3,850,000)
Contributions from noncontrolling interests	21,000,000	64,000
Distributions to noncontrolling interests	(5,128,000)	(2,694,000)
Acquisitions of noncontrolling interests	(6,000,000)	0
Net cash (used in) provided by financing activities	(996,000)	41,436,000
Net (decrease) increase in cash and equivalents	(72,259,000)	70,192,000
Cash and equivalents at beginning of period	333,220,000	217,486,000
Cash and equivalents at end of period	260,961,000	287,678,000
Operating Activities
Increase in land held for development and sale	(2,671,000)	(1,350,000)
(Increase) decrease in notes and accounts receivable	(5,039,000)	2,535,000
Decrease in other assets	18,000	1,869,000
Increase in accounts payable, accrued expenses and other liabilities	6,013,000	7,533,000
Total effect on operating activities	(1,679,000)	10,587,000
Investing Activities
Decrease (increase) in projects under construction and development	1,846,000	(14,713,000)
Decrease in completed rental properties	9,450,000	26,995,000
Decrease in restricted cash and escrowed funds	0	49,000
Decrease (increase) in investments in and advances to affiliates	207,000	(809,000)
Total effect on investing activities	11,503,000	11,522,000
Financing Activities
Decrease in nonrecourse mortgage debt and notes payable	(9,645,000)	(22,871,000)
Decrease in senior and subordinated debt	(138,514,000)	0
Increase in treasury stock	(12,868,000)	0
Decrease in preferred stock	(5,489,000)	0
Increase in Class A common stock	3,304,000	0
Increase (decrease) in additional paid-in capital	122,178,000	(1,116,000)
Increase in redeemable noncontrolling interest	6,305,000	2,980,000
Increase (decrease) in noncontrolling interest	24,905,000	(1,102,000)
Total effect on financing activities	(9,824,000)	(22,109,000)
Segment, Discontinued Operations [Member]
Depreciation and amortization	118,000	2,359,000
Amortization of mortgage procurement costs	0	113,000
Loss on extinguishment of debt	40,000	0
Impairment of real estate	0	1,381,000
Deferred income tax expense (benefit)	4,904,000	1,891,000
Gain on disposition of rental properties	$ (21,882,000)	$ (8,879,000)