Land Held for Divestiture (Details 2) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jul. 31, 2012
Fair value of land held for divestiture [Line Items]
Fair Value Valuation Technique Impairment of Real Estate	Indicative Bids
Fair Value Unobservable Input Impairment of Real Estate	Indicative Bids
Indicative bids [Member]
Fair value of land held for divestiture [Line Items]
Fair value of impairment of land held for divestiture	15,663
Fair Value Valuation Technique Impairment of Real Estate	Indicative bids
Fair Value Unobservable Input Impairment of Real Estate	Indicative bids
Undiscounted cash flows [Member]
Fair value of land held for divestiture [Line Items]
Fair value of impairment of land held for divestiture	926
Fair Value Valuation Technique Impairment of Real Estate	Undiscounted cash flows(2)