Stockholder's Investments - Schedule of Capital Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Class of Stock [Line Items]
Noncumulative Cash Dividend	$ 0.01665
Common Stock, Value, Issued	$ 548	$ 548	$ 548	$ 548
Common Class A [Member]
Class of Stock [Line Items]
Common Stock, Shares Authorized	100,000,000	100,000,000
Common Stock, Shares, Issued	51,261,487	51,261,487
Common Stock, Value, Issued	$ 513	$ 513
Class B Voting Common Stock [Member]
Class of Stock [Line Items]
Common Stock, Shares Authorized	10,000,000	10,000,000
Common Stock, Shares, Issued	3,538,628	3,538,628
Common Stock, Value, Issued	$ 35	$ 35
Noncumulative Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	5,000,000	5,000,000
6% Cumulative [Member] | Cumulative Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	5,000	5,000
1972 Series [Member] | Cumulative Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	10,000	10,000
1979 Series [Member] | Cumulative Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	30,000	30,000