Property, plant, and equipment (Tables)
|12 Months Ended|
Jul. 31, 2017
|Property, Plant and Equipment [Abstract]|
|Property, Plant and Equipment [Table Text Block]||At July 31, 2017 and 2016 property, plant, and equipment consist of:
Tabular disclosure of physical assets used in the normal conduct of business and not intended for resale. Includes, but is not limited to, balances by class of assets, depreciation and depletion expense and method used, including composite depreciation, and accumulated deprecation.
Reference 1: http://www.xbrl.org/2003/role/presentationRef