Loss On Disposal Of Subsidiaries (Details) (USD $)	3 Months Ended				12 Months Ended
	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2011	Apr. 30, 2011	Jan. 31, 2013	Jan. 31, 2012		Jan. 31, 2011
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on disposal of subsidiary	$ (28,294,000)	$ 0	$ 0	$ 0	$ 0	$ (28,294,000)	[1]	$ 0	[1]
Brazil and Colombia
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

[1] See Note 2 - Restatement of Consolidated Financial Statements.