CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	11 Months Ended	12 Months Ended
	Sep. 30, 2025	Oct. 31, 2024	Oct. 31, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 863.1	$ 295.5	$ 379.1
Other comprehensive income (loss), net of tax:
Foreign currency translation	113.5	2.5	(1.1)
Derivative financial instruments	(25.8)	(37.8)	(1.1)
Minimum pension liabilities	17.1	(4.4)	(11.9)
Other comprehensive (loss) income, net of tax	104.8	(39.7)	(14.1)
Comprehensive income	967.9	255.8	365.0
Comprehensive income attributable to noncontrolling interests	23.6	25.6	20.0
Comprehensive income attributable to Greif, Inc.	$ 944.3	$ 230.2	$ 345.0