EARNINGS PER SHARE - Computation of Earnings Per Share Basic and Diluted (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2019	Apr. 30, 2018
Numerator for basic and diluted EPS
Net income attributable to Greif, Inc.	$ 13.6	$ 45.1	$ 43.3	$ 101.6
Cash dividends	(26.1)	(24.8)	(51.8)	(49.3)
Undistributed net income (loss) attributable to Greif, Inc.	$ (12.5)	$ 20.3	$ (8.5)	$ 52.3