Marketable Securities (Schedule of Investment Securities In Continuous Unrealized Loss Position) (Details) - Corporate Equity Securities [Member] - USD ($) |
Apr. 30, 2018 |
Jul. 31, 2017 |
|---|---|---|
| Debt Securities, Available-for-sale [Line Items] | ||
| Investment securities, continuous unrealized loss position, Fair Value | $ 120,188 | |
| Investment securities, continuous unrealized loss position, Less Than 12 Months | $ 13,792 |