Commitments And Contingencies (Narrative) (Details) (USD $)			3 Months Ended	12 Months Ended
	Jan. 31, 2012	Jan. 31, 2011	Jul. 31, 2009 Synthetic Lease Facility [Member]	Jan. 31, 2012 Synthetic Lease Facility [Member] days years	Jan. 31, 2012 Operating Leases [Member]	Jan. 31, 2011 Operating Leases [Member]	Jan. 31, 2010 Operating Leases [Member]
Loss Contingencies [Line Items]
Rental expense for operating leases					$ 56,500,000	$ 53,500,000	$ 55,500,000
Option to purchase leased properties, period in force, years				4
Option expiration, days until lease expiration, days				180
Residual value guarantee, aggregate amount				107,400,000
Future minimum payments	221,200,000			2,700,000
Expiration date			June 2013
CIDE tax	32,000,000
Aggregate amount of guarantees	65,400,000	62,100,000
Aggregate amount of guarantees, outstanding	$ 28,400,000	$ 43,000,000