Information as to Reportable Segments and Foreign and Domestic Operations Information as to Reportable Segments and Foreign and Domestic Operations - Other (Details) - USD ($) $ in Thousands	12 Months Ended
Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Segment Reporting Information [Line Items]
Loss on sale of business	$ 0	$ 0	$ 2,206
Disposal by sale \| Specialty Packaging business \| Other
Segment Reporting Information [Line Items]
Loss on sale of business			$ 2,206

Gain (loss) from sale or disposal of an organization or integrated set of activities (for example, but not limited to, a partnership or corporation) engaged in providing a product or service in a commercial, industrial, or professional environment.

No definition available.

Name:	us-gaap_GainLossOnSaleOfBusiness
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration