Consolidated Statements of Equity (Unaudited) (USD $)	Total	Common Class A [Member]	Common Class B [Member]	Series A Preferred Stock [Member]	Additional Paid-In Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Loss	Noncontrolling Interest
Beginning Balance at Jan. 31, 2010	$ 1,504,840,000	$ 44,279,000	$ 7,505,000	$ 0	$ 571,189,000	$ 613,073,000	$ (154,000)	$ (87,266,000)	$ 356,214,000
Beginning Balance, Shares at Jan. 31, 2010		132,836,000	22,516,000	0			28,000
Cumulative effect of adoption of new consolidation accounting guidance	(74,034,000)								(74,034,000)
Net earnings, net of $262 and $1,879 attributable to redeemable noncontrolling interest	129,251,000					107,284,000			21,967,000
Other comprehensive loss, net of tax	(23,615,000)							(23,587,000)	(28,000)
Purchase of treasury stock	(711,000)						(711,000)
Purchase of treasury stock, Shares							50,000
Conversion of Class B to Class A shares		376,000	(376,000)
Conversion of Class B to Class A shares, Shares		1,129,000	(1,129,000)
Issuance of Series A preferred stock for cash (Note R)	44,456,000			50,000,000	(5,544,000)
Issuance of Series A preferred stock for cash (Note R), Shares				1,000,000
Issuance of Series A preferred stock in exchange for Senior Notes (Note R)	167,658,000			170,000,000	(2,342,000)
Issuance of Series A preferred stock in exchange for Senior Notes (Note R), Shares				3,400,000
Purchase of equity call hedge related to issuance of preferred stock (Note R)	(17,556,000)				(17,556,000)
Preferred stock dividends (Note R)	(4,107,000)					(4,107,000)
Purchase of Puttable Equity-Linked Senior Notes due 2011 (Note E)	7,000				7,000
Restricted stock vested		70,000			(70,000)
Restricted stock vested, Shares		210,000
Stock-based compensation	9,046,000				9,046,000
Excess income tax deficiency from stock-based compensation	(2,142,000)				(2,142,000)
Acquisition of partner's noncontrolling interest in consolidated subsidiary					500,000				(500,000)
Contributions from noncontrolling interests	3,581,000								3,581,000
Distributions to noncontrolling interests	(10,526,000)								(10,526,000)
Change in equity method of accounting related to disposition of partial interests in rental properties	23,493,000								23,493,000
Other changes in noncontrolling interests	(216,000)								(216,000)
Ending Balance at Jul. 31, 2010	1,749,425,000	44,725,000	7,129,000	220,000,000	553,088,000	716,250,000	(865,000)	(110,853,000)	319,951,000
Ending Balance, Shares at Jul. 31, 2010		134,175,000	21,387,000	4,400,000			78,000
Beginning Balance at Jan. 31, 2011	1,860,311,000	48,084,000	7,073,000	220,000,000	689,004,000	659,926,000	(259,000)	(94,429,000)	330,912,000
Beginning Balance, Shares at Jan. 31, 2011		144,252,000	21,219,000	4,400,000			21,000
Net earnings, net of $262 and $1,879 attributable to redeemable noncontrolling interest	140,933,000					55,701,000			85,232,000
Other comprehensive loss, net of tax	(10,690,000)							(11,730,000)	1,040,000
Purchase of treasury stock	(1,630,000)						(1,630,000)
Purchase of treasury stock, Shares							(87,000)
Conversion of Class B to Class A shares		77,000	(77,000)
Conversion of Class B to Class A shares, Shares		232,000	(232,000)
Issuance of Class A share in exchange for Convertible Senior Notes due 2016 (note E)	48,742,000	1,148,000			47,594,000
Issuance of Class A share in exchange for Convertible Senior Notes due 2016 (note E), Shares		3,444,000
Preferred stock dividends (Note R)	(7,700,000)					(7,700,000)
Restricted stock vested		110,000			(110,000)
Restricted stock vested, Shares		329,000
Exercise of stock options	177,000	4,000			158,000		15,000
Exercise of stock option, Shares		13,000					(1,000)
Stock-based compensation	6,325,000				6,325,000
Excess income tax deficiency from stock-based compensation	(785,000)				(785,000)
Redeemable noncontrolling interest adjustment	(1,986,000)				(1,986,000)
Acquisition of partner's noncontrolling interest in consolidated subsidiary	(19,101,000)				3,773,000				(22,874,000)
Contributions from noncontrolling interests	2,909,000								2,909,000
Distributions to noncontrolling interests	(82,367,000)								(82,367,000)
Change in equity method of accounting related to disposition of partial interests in rental properties	(33,598,000)								(33,598,000)
Other changes in noncontrolling interests	39,000								39,000
Ending Balance at Jul. 31, 2011	$ 1,901,579,000	$ 49,423,000	$ 6,996,000	$ 220,000,000	$ 743,973,000	$ 707,927,000	$ (1,874,000)	$ (106,159,000)	$ 281,293,000
Ending Balance, Shares at Jul. 31, 2011		148,270,000	20,987,000	4,400,000			107,000