Basis of Presentation (Details)	Jul. 31, 2011
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Company's interest in the joint venture - NSN	60.00%

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

No definition available.

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant