Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 124.3	$ 194.2	$ 229.5
Other comprehensive income (loss), net of tax:
Foreign currency translation	(9.8)	(4.5)	(45.5)
Derivative financial instruments	(12.0)	(26.1)	7.7
Minimum pension liabilities	15.1	(25.3)	16.3
Other comprehensive income (loss), net of tax	(6.7)	(55.9)	(21.5)
Comprehensive income	117.6	138.3	208.0
Comprehensive income attributable to noncontrolling interests	2.6	23.9	18.1
Comprehensive income attributable to Greif, Inc.	$ 115.0	$ 114.4	$ 189.9