Consolidated Statements of Equity (USD $)	Total	Additional Paid-In Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Loss (Income)	Noncontrolling Interest	Series A Preferred Stock	Common Stock Class A	Common Stock Class B	Previously reported	Previously reported Additional Paid-In Capital	Previously reported Retained Earnings	Previously reported Treasury Stock	Previously reported Accumulated Other Comprehensive Loss (Income)	Previously reported Noncontrolling Interest	Previously reported Common Stock Class A	Previously reported Common Stock Class B	Adjusted	Adjusted Additional Paid-In Capital	Adjusted Retained Earnings	Adjusted Treasury Stock	Adjusted Accumulated Other Comprehensive Loss (Income)	Adjusted Noncontrolling Interest	Adjusted Common Stock Class A	Adjusted Common Stock Class B
Balance at Jan. 31, 2009										$ 1,176,099,000	$ 267,796,000	$ 643,724,000	$ (21,000)	$ (107,521,000)	$ 337,828,000	$ 26,694,000	$ 7,599,000	$ 1,186,987,000	$ 267,796,000	$ 654,612,000	$ (21,000)	$ (107,521,000)	$ 337,828,000	$ 26,694,000	$ 7,599,000
Balance, Shares at Jan. 31, 2009													2,000			8,082,000	22,798,000				2,000			80,082,000	22,798,000
Allowance for projects under development revision	10,888,000		10,888,000
Net loss	(20,368,000)		(26,978,000)			6,610,000
Other comprehensive loss, net of tax	20,578,000				20,255,000	323,000
Issuance of Class A Common shares in equity offering	329,917,000	312,475,000						17,442,000
Issuance of Class A Common shares in equity offering, shares								52,325,000
Purchase of treasury stock	(133,000)			(133,000)
Purchase of treasury stock, Shares	26,188			26,000
Conversion of Class B to Class A shares								94,000	(94,000)
Conversion of Class B to Class A shares, Shares								282,000	(282,000)
Purchase of Convertible Senior Note hedge, net of tax	(9,734,000)	(9,734,000)
Restricted stock vested		(44,000)						44,000
Restricted stock vested, Shares								132,000
Exercise of stock options	128,000	123,000						5,000
Exercise of stock options, shares								15,000
Stock-based compensation	16,738,000	16,738,000
Excess income tax deficiency from stock-based compensation	(2,068,000)	(2,068,000)
Exchange of Puttable Equity-Linked Senior Notes due 2011	(17,490,000)	(17,490,000)
Acquisition of partners' noncontrolling interest in consolidated subsidiaries		3,393,000				(3,393,000)
Contributions from noncontrolling interests	21,831,000					21,831,000
Distributions to noncontrolling interests	(12,339,000)					(12,339,000)
Change to full consolidation method of accounting for a subsidiary	5,010,000					5,010,000
Other changes in noncontrolling interests	344,000					344,000
Balance at Jan. 31, 2010	1,519,401,000	571,189,000	627,634,000	(154,000)	(87,266,000)	356,214,000		44,279,000	7,505,000
Balance, Shares at Jan. 31, 2010				28,000				132,836,000	22,516,000
Net loss	85,398,000
Net earnings, net of $1,925 and $4,567 attributable to redeemable noncontrolling interest	87,323,000		58,048,000			29,275,000
Cumulative effect of adoption of new consolidation accounting guidance	(74,034,000)					(74,034,000)
Other comprehensive loss, net of tax	(7,226,000)				(7,163,000)	(63,000)
Purchase of treasury stock	(786,000)			(786,000)
Purchase of treasury stock, Shares	54,732			54,000
Conversion of Class B to Class A shares								432,000	(432,000)
Conversion of Class B to Class A shares, Shares								1,297,000	(1,297,000)
Issuance of Class A share in exchange for Convertible Senior Notes	136,444,000	133,186,000						3,258,000
Issuance of Class A share in exchange for Convertible Senior Notes, Shares								9,774,000
Proceeds received from partial termination of Convertible Senior Notes hedge	1,869,000	1,869,000
Issuance of Series A preferred stock for cash	44,456,000	(5,544,000)					50,000,000
Issuance of Series A preferred stock for cash, Shares							1,000,000
Issuance of Series A preferred stock in exchange for Senior Notes	167,658,000	(2,342,000)					170,000,000
Issuance of Series A preferred stock in exchange for Senior Notes, Shares							3,400,000
Purchase of equity call hedge related to issuance of preferred stock	(17,556,000)	(17,556,000)
Preferred dividends	(11,807,000)		(11,807,000)				(11,807,000)
Purchase of Puttable Equity-Linked Senior Notes due 2011	7,000	7,000
Restricted stock vested		(74,000)						74,000
Restricted stock vested, Shares								222,000
Exercise of stock options	2,621,000	1,899,000		681,000				41,000
Exercise of stock options, shares				(61,000)				123,000
Stock-based compensation	14,931,000	14,931,000
Excess income tax deficiency from stock-based compensation	(2,216,000)	(2,216,000)
Redeemable noncontrolling interest adjustment	(6,845,000)	(6,845,000)
Acquisition of partners' noncontrolling interest in consolidated subsidiaries		500,000				(500,000)
Contributions from noncontrolling interests	18,136,000					18,136,000
Distributions to noncontrolling interests	(20,777,000)					(20,777,000)
Change to equity method of accounting due to disposition of partial interests in rental properties	23,493,000					23,493,000
Other changes in noncontrolling interests	(832,000)					(832,000)
Balance at Jan. 31, 2011	1,874,260,000	689,004,000	673,875,000	(259,000)	(94,429,000)	330,912,000	220,000,000	48,084,000	7,073,000
Balance, Shares at Jan. 31, 2011				21,000			4,400,000	144,252,000	21,219,000
Balance at Dec. 31, 2010
Issuance of Class A share in exchange for Convertible Senior Notes, Shares								9,774,039
Balance at Jan. 31, 2011	1,874,260,000	689,004,000	673,875,000	(259,000)	(94,429,000)	330,912,000	220,000,000	48,084,000	7,073,000
Balance, Shares at Jan. 31, 2011				21,000			4,400,000	144,252,000	21,219,000
Net loss	(568,000)
Net earnings, net of $1,925 and $4,567 attributable to redeemable noncontrolling interest	3,999,000		(86,486,000)			90,485,000
Other comprehensive loss, net of tax	(24,981,000)				(26,031,000)	1,050,000
Purchase of treasury stock	(1,670,000)			(1,670,000)
Purchase of treasury stock, Shares	90,104			90,000
Conversion of Class B to Class A shares								95,000	(95,000)
Conversion of Class B to Class A shares, Shares								284,000	(284,000)
Issuance of Class A share in exchange for Convertible Senior Notes	48,742,000	47,594,000						1,148,000
Issuance of Class A share in exchange for Convertible Senior Notes, Shares								3,444,000
Preferred dividends	(15,400,000)		(15,400,000)				(15,400,000)
Restricted stock vested		(114,000)						114,000
Restricted stock vested, Shares								343,000
Exercise of stock options	195,000	136,000		55,000				4,000
Exercise of stock options, shares				(3,000)				13,000
Stock-based compensation	12,585,000	12,585,000
Excess income tax deficiency from stock-based compensation	(812,000)	(812,000)
Redeemable noncontrolling interest adjustment	(6,887,000)	(6,887,000)
Acquisition of partners' noncontrolling interest in consolidated subsidiaries	(20,953,000)	(518,000)				(20,435,000)
Contributions from noncontrolling interests	6,087,000					6,087,000
Distributions to noncontrolling interests	(89,644,000)					(89,644,000)
Change to equity method of accounting for subsidiaries	(33,598,000)					(33,598,000)
Other changes in noncontrolling interests	(51,000)					(51,000)
Balance at Jan. 31, 2012	$ 1,751,872,000	$ 740,988,000	$ 571,989,000	$ (1,874,000)	$ (120,460,000)	$ 284,806,000	$ 220,000,000	$ 49,445,000	$ 6,978,000
Balance, Shares at Jan. 31, 2012				108,000			4,000,000	148,336,000	20,935,000