Term Receivable and Trade Accounts Receivable Balances (Detail) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2014	Jan. 31, 2014
Accounts and Financing Receivable [Line Items]
Trade accounts receivable, net	$ 423,699	$ 454,483
Term receivables, long-term	236,743	270,365
Trade accounts receivable
Accounts and Financing Receivable [Line Items]
Trade accounts receivable, net	112,530	179,830
Term receivables, short-term
Accounts and Financing Receivable [Line Items]
Trade accounts receivable, net	$ 311,169	$ 274,653

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.3-4)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 3

-Subparagraph a(1)

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 4

-Article 5

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