Document and Entity Information - shares	3 Months Ended
	Feb. 29, 2020	Apr. 03, 2020
Document and Entity Information
Document Type	10-Q
Document Period End Date	Feb. 29, 2020
Entity Registrant Name	GRIFFIN INDUSTRIAL REALTY, INC.
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Interactive Data Current	Yes
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		5,128,413
Current Fiscal Year End Date	--11-30
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001037390
Amendment Flag	false