DOCUMENT AND ENTITY INFORMATION - shares	3 Months Ended
	Oct. 31, 2019	Dec. 05, 2019
Document And Entity Information [Abstract]
Entity Registrant Name	MAYS J W INC
Entity Central Index Key	0000054187
Document Type	10-Q
Document Period End Date	Oct. 31, 2019
Document Fiscal Period Focus	Q1
Amendment Flag	false
Current Fiscal Year End Date	--07-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Document Fiscal Year Focus	2020
Entity Common Stock, Shares Outstanding		2,015,780
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Incorporation State Country Code	NY
Entity File Number	11-1059070