Discontinued Operations and Gain on Disposition of Rental Properties (Details 4) (USD $)	3 Months Ended		9 Months Ended
	Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2013	Oct. 31, 2012
Gain Loss on Equity Method Investments [Line Items]
Gain (loss) on disposition of unconsolidated entities	$ 34,281,000	$ 0	$ 32,771,000	$ 16,107,000
Westin Convention Center (Hotel) [Member]
Gain Loss on Equity Method Investments [Line Items]
Gain (loss) on disposition of unconsolidated entities	32,741,000	0	32,741,000	0
LIberty Center (Office Buildings) [Member]
Gain Loss on Equity Method Investments [Line Items]
Gain (loss) on disposition of unconsolidated entities	1,540,000	0	1,540,000	0
Chagrin Plaza I & II (Office Buildings) [Member]
Gain Loss on Equity Method Investments [Line Items]
Gain (loss) on disposition of unconsolidated entities	0	0	0	1,628,000
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	$ 0	$ 0	$ 14,479,000