Consolidated Balance Sheets (Parenthetical) (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified			6 Months Ended	12 Months Ended
	Jul. 31, 2012 Variable interest entities	Jan. 31, 2012 Variable interest entities	Jul. 31, 2012 Series A Preferred Stock	Jan. 31, 2012 Series A Preferred Stock	Jul. 31, 2012 Other Preferred Stock	Jan. 31, 2012 Other Preferred Stock	Jul. 31, 2012 Common Stock Class A	Jan. 31, 2012 Common Stock Class A	Jul. 31, 2012 Common Stock Class B	Jan. 31, 2012 Common Stock Class B
Real Estate, net	$ 2,318,200	$ 2,103,800
Cash and equivalents	32,900	17,800
Restricted cash and escrowed funds	172,800	348,100
Other assets	130,200	130,800
Mortgage debt and notes payable, nonrecourse	1,224,300	1,122,000
Senior and Subordinated debt	29,000	29,000
Accounts payable, accrued expenses and other liabilities	$ 217,600	$ 171,000
Preferred stock, liquidation preference			$ 50	$ 50
Preferred stock, shares authorized			6,400,000	6,400,000	13,600,000	13,600,000
Preferred stock, shares issued			4,399,998	4,399,998	0	0
Preferred stock, shares outstanding			4,399,998	4,399,998
Preferred Stock, without par value					$ 0	$ 0
Preferred stock dividend rate			7.00%	7.00%
Price per share							$ 0.333	$ 0.333	$ 0.333	$ 0.333
Common stock, shares authorized							371,000,000	371,000,000	56,000,000	56,000,000
Common stock, shares issued							148,855,516	148,336,178	20,858,777	20,934,335
Common stock, shares outstanding							148,642,140	148,227,849	20,858,777	20,934,335
Common stock, shares issuable									26,257,961	26,257,961
Treasury stock, Class A Shares							213,376	108,329