Investments in Unconsolidated Entities (Details 3) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2011	Jul. 31, 2010
Gain (loss) on disposition of unconsolidated investments:
Gain (loss) on disposition of equity method investments	$ 0	$ (878)	$ 12,567	$ (830)
Metreon [Member]
Gain (loss) on disposition of unconsolidated investments:
Gain (loss) on disposition of equity method investments	0	(1,046)	0	(1,046)
Coachella Plaza [Member]
Gain (loss) on disposition of unconsolidated investments:
Gain (loss) on disposition of equity method investments	0	104	0	104
Southgate Mall [Member]
Gain (loss) on disposition of unconsolidated investments:
Gain (loss) on disposition of equity method investments	0	64	0	64
El Centro Mall [Member]
Gain (loss) on disposition of unconsolidated investments:
Gain (loss) on disposition of equity method investments	0		0	48
Metropolitan Lofts [Member]
Gain (loss) on disposition of unconsolidated investments:
Gain (loss) on disposition of equity method investments	0	0	9,964	0
Twin Lake Towers [Member]
Gain (loss) on disposition of unconsolidated investments:
Gain (loss) on disposition of equity method investments	$ 0	$ 0	$ 2,603	$ 0