Marketable Securities (Schedule of investment income) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2016	Jan. 31, 2015
Marketable Securities: [Abstract]
Gain (loss) on sale of marketable securities	$ (38,538)		$ (38,538)	$ 386
Interest income	756	$ 662	1,665	1,287
Dividend income	37,702	25,691	44,015	30,871
Total	$ (80)	$ 26,353	$ 7,142	$ 32,544