CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Unaudited) - USD ($)	Common Stock	Additional Paid In Capital	Unrealized Gain on Marketable securities [Member]	Retained Earnings	Common Stock Held in Treasury	Total
Balance at Jul. 31, 2018	$ 2,178,297	$ 3,346,245	$ 487,136	$ 48,369,386	$ (1,287,852)	$ 53,093,212
Reclassification of unrealized gains on marketable securities to retained earnings (Note 1)			(487,136)	487,136
Net income (loss)				214,766		214,766
Balance at Jan. 31, 2019	2,178,297	3,346,245		49,071,288	(1,287,852)	53,307,978
Balance at Oct. 31, 2018	2,178,297	3,346,245		48,777,328	(1,287,852)	53,014,018
Net income (loss)				293,960		293,960
Balance at Jan. 31, 2019	2,178,297	3,346,245		49,071,288	(1,287,852)	53,307,978
Balance at Jul. 31, 2019	2,178,297	3,346,245		50,371,323	(1,287,852)	54,608,013
Net income (loss)				71,263		71,263
Balance at Jan. 31, 2020	2,178,297	3,346,245		50,442,586	(1,287,852)	54,679,276
Balance at Oct. 31, 2019	2,178,297	3,346,245		50,499,867	(1,287,852)	54,736,557
Net income (loss)				(57,281)		(57,281)
Balance at Jan. 31, 2020	$ 2,178,297	$ 3,346,245		$ 50,442,586	$ (1,287,852)	$ 54,679,276