Discontinued Operations and Gain on Disposition of Rental Properties (Details 4) (USD $)	3 Months Ended		6 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2013	Jul. 31, 2012
Gain Loss on Equity Method Investments [Line Items]
Gain (loss) on disposition of unconsolidated entities	$ 0	$ 16,107,000	$ (1,510,000)	$ 16,107,000
Plaza at Robinson Town Center (Specialty Retail Center) [Member]
Gain Loss on Equity Method Investments [Line Items]
Gain (loss) on disposition of unconsolidated entities	0	0	(1,510,000)	0
Village at Gulfstream Park (Specialty Retail Center) [Member]
Gain Loss on Equity Method Investments [Line Items]
Gain (loss) on disposition of unconsolidated entities	0	14,479,000	0	14,479,000
Chagrin Plaza I & II (Office Buildings) [Member]
Gain Loss on Equity Method Investments [Line Items]
Gain (loss) on disposition of unconsolidated entities	$ 0	$ 1,628,000	$ 0	$ 1,628,000