Loss On Disposal Of Subsidiaries (Details) (USD $)	3 Months Ended	12 Months Ended
	Jan. 31, 2012	Jan. 31, 2012	Jan. 31, 2011	Jan. 31, 2010
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on disposal of subsidiary	$ (28,300,000)	$ (28,294,000)	$ 0	$ 0
Brazil [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Foreign currency exchange loss, recorded in accumulated other comprehensive income	9,900,000
Write-off off of certain value-added tax receivables	15,300,000
Severance costs, fixed asset write-offs and lease termination penalties	$ 3,100,000