Credit Risk Assessment for Long-term Receivables (Detail) (USD $) In Thousands, unless otherwise specified	Oct. 31, 2013	Jan. 31, 2013
Accounts and Financing Receivable [Line Items]
Term receivables, long-term	$ 241,122	$ 250,497
S&P credit rating, AAA+ through BBB-
Accounts and Financing Receivable [Line Items]
Term receivables, long-term	145,516	133,773
S&P credit rating, BB+ and lower
Accounts and Financing Receivable [Line Items]
Term receivables, long-term	34,716	45,298
S&P credit rating
Accounts and Financing Receivable [Line Items]
Term receivables, long-term	180,232	179,071
Internal Credit Rating
Accounts and Financing Receivable [Line Items]
Term receivables, long-term	$ 60,890	$ 71,426

Amount due from customers or clients, more than one year from the balance sheet date, for goods or services 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 210.5-02.17)

-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

-Article 5

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