Acquisitions (Details Narrative) - USD ($)				1 Months Ended					3 Months Ended		6 Months Ended	9 Months Ended
	May 22, 2019	Nov. 02, 2018	Oct. 03, 2018	May 22, 2019	Apr. 30, 2019	Nov. 28, 2018	Nov. 27, 2018	Dec. 28, 2017	Apr. 30, 2019	Apr. 30, 2018	Jan. 18, 2017	Apr. 30, 2019	Apr. 30, 2018	Apr. 23, 2019	Apr. 08, 2019	Feb. 15, 2019	Feb. 04, 2019	Jan. 07, 2019	Dec. 01, 2018	Oct. 26, 2018	Jul. 31, 2018	Feb. 09, 2017
Acquisition of interest											51.00%
Acquisition of outstanding limited liability company units											4,950
Value of shares exchanged for outstanding limited liability units											$ 253,721
Common stock issued					60,362,163				60,362,163		1,117,011	60,362,163								4,830,000	22,430,121	2,179,989
Limited liability company units receied											300
Call Option											$ 13,431,706
Call option recorded as an asset																					$ 2,168,211
Changes in fair value of contingent purchase consideration										$ 4,573,493		15,147,591	$ 23,350,122
Warrant issued to acquire stock											15,000,000
Common stock, price per year											$ 2.50
Total consideration											$ 1,350,916
Intangible assets acquired											2,911,377
Aggregate purchase price											$ 1
Promissory Note								$ 320,000
Promissory Note, Due Date								Jun. 28, 2018
Promissory Note, interest rate								3.00%						10.00%	10.00%	10.00%	10.00%			27.50%
Goodwill impairment								$ 99,519
Business combination description		On November 1, 2018 we consummated the acquisition of the Second Closing Assets, consisting primarily of Veneto’s management services organization business and two additional ancillary services. The aggregate price for the First Closing Assets and the Second Closing Assets was $30,000,000. The Company issued a promissory note in the principal amount of $35,000,000 (the “New Note”) consisting of the $30,000,000 purchase price and a $5,000,000 original issue discount, as the sole consideration payable on the Second Closing Date. In addition, we agreed to assume approximately $3.8 million in outstanding institutional debt of Veneto subsidiaries, but will have use of Veneto cash which would otherwise have been applied to paying down the debt.
Payment of Promissory Note					$ 320,000							$ 320,000
Subsequent Event [Member]
Payment of Promissory Note	$ 4,361,500			$ 4,800,000
Berkman
Common stock, price per year																			$ 2.50
Shares exercisable																			15,000,000
Veneto Holdings, L.L.C.
Business combination description			The aggregate purchase price for the Assets, is $35,000,000 including the Promissory Note. At the Second Closing, the Company will pay the principal of the Promissory Note plus interest to Veneto, (i) $9,000,000 will be paid by the Company into a trust or other fiduciary account acceptable to Veneto to be used exclusively for satisfaction of certain contingent liabilities of Veneto and subsidiaries of Veneto not being acquired by the Company, (ii) $3,000,000 will be paid by the Company into an escrow account to secure potential obligations of Veneto in respect of the Second Closing date working capital and under the indemnification provisions of the Agreement and (iii) the balance will be payable directly to Veneto in cash.
Olaregen
Business combination description							The Company will purchase 3,282,632 newly issued shares of the Olaregen common stock representing 51% percent of the issued and outstanding capital stock of Olaregen (“Olaregen Shares”).
LOI description							On November 27, 2018, Generex Biotechnology Corporation (the “Company”) and Olaregen Therapeutix Inc. (“Olaregen”) entered into a binding letter of intent (“LOI”) contemplating the Company’s acquisition of 51% of the outstanding capital stock of Olaregen for a total consideration of twelve million dollars ($12,000,000). As of January 7, 2019, the Company completed a definitive Stock Purchase Agreement (“Purchase Agreement”) and related documents effecting the transactions contemplated by the LOI.
Deferred tax liability							$ 1,040,173
Regentys
Acquisition of interest						51.00%
Business combination description						Pursuant to a Stock Purchase Agreement between the Company and Regentys (the “Purchase Agreement”) the Company purchased 12,048,161 newly issued shares of the Regentys common stock representing 51% percent of the issued and outstanding capital stock of Regentys (“Regentys Shares”). In addition to $400,000 paid to Regentys upon signing of the LOI, the purchase price for the Regentys Shares will consist of the following cash payments, with the proceeds intended to be used for specific purposes, as noted: • $3,450,000 to initiate pre-clinical activities on or before January 15, 2018. • $2,000,000 to initiate patient recruitment activities on or before May 1, 2019. • $3,000,000 to initiate a first-in-human pilot study on or before September 1, 2019. • $5,000,000 to initiate a human pivotal study on or before February 1, 2020. The Company issued its Promissory Note in the amount of $14,600,000 (the “Note’) representing its obligation to pay the above amounts. The Note is secured by a pledge of the Regentys pursuant to a Pledge and Security Agreement. In the event that Generex does not make any of the first three payments listed above, at Regentys’ option either: • Generex will forfeit all of the Regentys shares issued with no refund of amounts paid; or • Generex will issue shares of its common stock to Regentys equivalent to 110% of the value of the missing payment, which shares will be registered for resale.
LOI description						On November 28, 2018, Generex Biotechnology Corporation (the “Company”) and Regentys Corporation. (“Regentys”) closed the acquisition of 51% of the outstanding capital stock of Regentys for a total consideration of fifteen million dollars ($15,000,000). On January 7, 2019 the Company completed a definitive Stock Purchase Agreement and related documents effecting the transactions contemplated by the LOI.
Deferred tax liability																		$ 889,782
Post Reverse Stock Split
Common stock issued											4,830,000
At Closing
Common stock issued											1,117,011
Net Purchase Price
Common stock issued											5,947,431
After Closing
Common stock issued											420