CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Cash flows from operating activities:
Net income	$ 197.2	$ 73.1
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	117.5	133.9
Non-cash asset impairment charges	4.7	17.5
Non-cash pension settlement charges	1.6	0.0
Gain on disposals of properties, plants and equipment, net	(217.4)	(2.3)
Loss on disposals of businesses, net	3.1	1.3
Unrealized foreign exchange (gain) loss	0.4	0.0
Deferred income tax benefit	(50.8)	(86.1)
Debt extinguishment charges	0.7	0.0
Non-cash special charitable contribution	40.0	0.0
Non-cash lease expense	26.0	24.9
Other, net	0.6	0.8
Increase (decrease) in cash from changes in certain assets and liabilities, net of impacts from acquisitions:
Trade accounts receivable	(52.7)	(14.6)
Inventories	(2.6)	(7.5)
Accounts payable	89.0	(1.3)
Restructuring reserves	(4.5)	5.5
Operating leases	(26.9)	(24.2)
Pension and post-retirement benefit liabilities	(4.5)	(4.1)
Other, net	(29.2)	22.1
Net cash provided by operating activities	92.2	139.0
Cash flows from investing activities:
Purchases of business, net of cash acquired	(5.3)	(1.2)
Purchases of properties, plants and equipment	(89.8)	(81.3)
Payments for deferred purchase price of acquisitions	(0.6)	(1.2)
Proceeds from the sale of properties, plants, equipment and other assets	463.4	6.4
Payments for the sale of businesses	0.0	(0.9)
Proceeds from hedging derivatives	0.0	22.5
Other, net	(0.3)	(3.6)
Net cash provided by (used in) investing activities	367.4	(59.3)
Cash flows from financing activities:
Proceeds from issuance of long-term debt	1,667.4	1,110.0
Payments on long-term debt	(1,868.9)	(1,064.0)
Proceeds (payments) on short-term borrowings, net	0.2	(16.3)
Proceeds from trade accounts receivable credit facility	46.0	61.3
Payments on trade accounts receivable credit facility	(40.3)	(57.9)
Dividends paid to Greif, Inc. shareholders	(64.3)	(62.4)
Dividends paid to noncontrolling interests	(9.8)	(14.4)
Payments for debt extinguishment and issuance costs	(2.8)	0.0
Payments for share repurchases	(147.2)	0.0
Tax withholding payments for stock-based awards	(9.8)	(7.4)
Other, net	(0.8)	(3.6)
Net cash used in financing activities	(430.3)	(54.7)
Effects of exchange rates on cash	0.1	1.9
Net increase in cash and cash equivalents	29.4	26.9
Cash and cash equivalents at beginning of period	256.7	216.4
Cash and cash equivalents at end of period	$ 286.1	$ 243.3