Consolidated Balance Sheets (Parenthetical) (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified			3 Months Ended
	Apr. 30, 2013 Variable interest entities	Apr. 30, 2012 Variable interest entities	Apr. 30, 2013 Series A Preferred Stock	Apr. 30, 2012 Series A Preferred Stock	Apr. 30, 2013 Other Preferred Stock	Apr. 30, 2012 Other Preferred Stock	Apr. 30, 2013 Common Stock Class A	Apr. 30, 2012 Common Stock Class A	Apr. 30, 2013 Common Stock Class B	Apr. 30, 2012 Common Stock Class B
Real Estate, net	$ 1,366,700	$ 1,416,900
Cash and equivalents	13,300	14,200
Restricted cash and escrowed funds	162,200	114,900
Other assets	86,600	92,500
Mortgage debt and notes payable, nonrecourse	594,100	624,100
Senior and subordinated debt	29,000	29,000
Accounts payable, accrued expenses and other liabilities	$ 83,100	$ 76,200
Preferred stock, dividend rate			7.00%	7.00%
Preferred Stock, without par value			$ 0	$ 0	$ 0	$ 0
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			0	211,038	0	0
Preferred stock, shares outstanding			0	211,038
Common stock, par value 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							174,323,829	163,729,240	20,216,683	20,235,273
Common stock, shares outstanding							173,373,837	163,722,658	20,216,683	20,235,273
Common stock, shares issuable									26,257,961	26,257,961
Treasury stock, Class A Shares							949,992	6,582