EARNINGS PER SHARE - Computation of Earnings Per Share Basic and Diluted (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2020	Jul. 31, 2019
Numerator for basic and diluted EPS
Net income attributable to Greif, Inc.	$ 20.7	$ 62.7	$ 64.4	$ 106.0
Cash dividends	(26.2)	(26.1)	(78.2)	(77.9)
Undistributed net income attributable to Greif, Inc.	$ (5.5)	$ 36.6	$ (13.8)	$ 28.1