CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2021	Jul. 31, 2020	Jul. 31, 2021	Jul. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 118.4	$ 24.4	$ 303.3	$ 76.3
Other comprehensive income (loss), net of tax:
Foreign currency translation	(15.5)	59.6	18.7	4.2
Derivative financial instruments	(0.6)	2.0	10.8	(20.9)
Minimum pension liabilities	2.2	(2.4)	49.3	20.6
Other comprehensive income (loss), net of tax	(13.9)	59.2	78.8	3.9
Comprehensive income	104.5	83.6	382.1	80.2
Comprehensive income attributable to noncontrolling interests	5.6	0.9	17.9	3.5
Comprehensive income attributable to Greif, Inc.	$ 98.9	$ 82.7	$ 364.2	$ 76.7