Supplementary Balance Sheet Information Composition of Property, Plant and Equipment under Capital Lease (Details) - Canyons [Member] - USD ($) $ in Thousands	Jul. 31, 2018	Jul. 31, 2017
Property, Plant and Equipment [Line Items]
Capital Leased Assets, Land	$ 31,818	$ 31,818
Capital Leased Assets, Land Improvements	49,228	49,228
Capital Leased Assets, Buildings and Building Improvements	42,660	42,910
Capital Leased Assets, Machinery and Equipment	60,384	61,156
Capital Leased Assets, Gross	184,090	185,112
Capital Leased Assets, Accumulated Depreciation	(46,502)	(37,000)
Capital Leased Assets, Net	$ 137,588	$ 148,112