Impairment of Real Estate, Impairment of Unconsolidated Entities and Write-Off of Abandoned Development Projects (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2013
Indicative bids [Member]
Non-recurring Impairment of Real Estate Including Discontiued Operations
Fair value of impairment of real estate	$ 83,193
Fair value valuation technique	Indicative Bids
Fair value unobservable input	Indicative Bids
Fair value range of input values impairment of real estate	N/A	[1]
Discounted cash flow [Member]
Non-recurring Impairment of Real Estate Including Discontiued Operations
Fair value of impairment of real estate	$ 10,500
Fair value valuation technique	Discounted Cash Flow
Fair value unobservable input	Discount Rate
Percentage of input values impairment of real estate	10.00%

[1] These fair value measurements were derived from five bona fide purchase offers from third party prospective buyers, subject to the Company’s corroboration for reasonableness.