Class A Common Units (Details) (USD $)	Jul. 31, 2011	Jan. 31, 2011
Class Common Units (Textuals)
Number of retail, office and residential operating properties, and certain service companies	30
Common Class A [Member]
Class of Stock [Line Items]
Carrying value of Class A Common Units	$ 186,021,000	$ 186,021,000
Class A Common Units, Outstanding Units	3,646,755	3,646,755