Fair Value Measurement - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2013	Jan. 31, 2012
Disclosure Fair Value Measurement Additional Information [Abstract]
Fair value of contingent consideration included in accrued liabilities	$ 1,197	$ 510
Fair value of contingent consideration included in other long term liabilities	4,819	5,610
Current portion of notes payable	$ 0	$ 1,349

Sum of the carrying values as of the balance sheet date of the portions of all long-term notes and loans payable due within one year or the operating cycle if longer.

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 210.5-02.19,20)

-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 19, 20

-Article 5

Name:	us-gaap_NotesAndLoansPayableCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant