Related Party Transactions Related Party Transactions - Additional Information (Details) - USD ($) $ in Thousands	Jul. 31, 2015	Jan. 31, 2015
Related Party Transaction [Line Items]
Accounts receivable due from related party	$ 16,237	$ 46,661

For an unclassified balance sheet, amounts due from related parties including affiliates, employees, joint ventures, officers and stockholders, immediate families thereof, and pension funds.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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Name:	us-gaap_DueFromRelatedParties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant