Commitments and Contingencies Leases (Details) (USD $)	12 Months Ended
	Jan. 31, 2012	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2008
Sale Leaseback Transaction [Line Items]
Expense Due To Acceleration Of Useful Lives	$ 11,835,000
Deferred gains on sale-leasebacks		64,471,000	81,865,000	144,505,000
Actual Expense Incurred For Headquarters Relocation	42,719,000
Lease Exit Charge	$ 30,884,000
Minimum [Member]
Sale Leaseback Transaction [Line Items]
Amortization Period of Sale-Leaseback Deferred Gains		15 years
Maximum [Member]
Sale Leaseback Transaction [Line Items]
Amortization Period of Sale-Leaseback Deferred Gains		20 years