Cover Page - shares	3 Months Ended
	Jan. 31, 2021	Feb. 22, 2021
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jan. 31, 2021
Document Transition Report	false
Entity File Number	001-00566
Entity Registrant Name	GREIF, INC
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	31-4388903
Entity Address, Address Line One	425 Winter Road
Entity Address, City or Town	Delaware
Entity Address, State or Province	OH
Entity Address, Postal Zip Code	43015
City Area Code	740
Local Phone Number	549-6000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Central Index Key	0000043920
Current Fiscal Year End Date	--10-31
Class A Common Stock
Document Information [Line Items]
Title of 12(b) Security	Class A Common Stock
Trading Symbol	GEF
Security Exchange Name	NYSE
Entity Common Stock, Shares Outstanding		26,525,238
Class B Common Stock
Document Information [Line Items]
Title of 12(b) Security	Class B Common Stock
Trading Symbol	GEF-B
Security Exchange Name	NYSE
Entity Common Stock, Shares Outstanding		22,007,725