Fair Value Measurements (Details 5) (USD $)	6 Months Ended	12 Months Ended
Jan. 31, 2014	Jul. 31, 2013
Fair Value Measurements
Impairment of long-lived assets, including goodwill and intangibles with indefinite lives	$ 0
Minimum
Disclosure of Fair Value of Financial Instruments
Interest rate base	One month LIBOR	One month LIBOR
Maximum
Disclosure of Fair Value of Financial Instruments
Interest rate base	Twelve month LIBOR	Twelve month LIBOR

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2420-110228

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration