Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	Jul. 31, 2012 CreditFacility
Commitments and Contingencies (Textual) [Abstract]
Domestic bank group had issued irrevocable standby letters of credit	5
Outstanding letters of credit	$ 20.7
Obligations to third parties in various foreign currencies	$ 2.1

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

No definition available.

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