Retention Retention payable (Details) (USD $) In Millions, unless otherwise specified	Jan. 31, 2013	Jan. 31, 2012
Retention Payable, Fiscal Year Maturity [Abstract]
Retention payable	$ (0.5)	$ (0.4)

Amounts owed to vendors and subcontractors that have been withheld because of retainage provisions in a contract.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 910

-SubTopic 405

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6471548&loc=d3e50610-109371

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