Debt not Carried at Fair Value (Detail) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2015	Jul. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable	$ 76,696us-gaap_LongTermNotesPayable	$ 73,391us-gaap_LongTermNotesPayable
Notes payable, Fair Value	$ 90,813us-gaap_NotesPayableFairValueDisclosure	$ 93,750us-gaap_NotesPayableFairValueDisclosure

Carrying value as of the balance sheet date of notes payable (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion.

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 210.5-02.22)

-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 22

-Article 5

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