WestRock (WRK) 10-Q 5 May 23 2023 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Mar. 31, 2023	Apr. 21, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Trading Symbol	WRK
Entity Registrant Name	WestRock Company
Entity Central Index Key	0001732845
Current Fiscal Year End Date	--09-30
Entity Filer Category	Large Accelerated Filer
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		256,130,237
Entity Current Reporting Status	Yes
Title of 12(b) Security	Common Stock, par value $0.01 per share
Entity File Number	001-38736
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	37-1880617
Entity Interactive Data Current	Yes
Security Exchange Name	NYSE
Entity Address, Address Line One	1000 Abernathy Road NE
Entity Address, City or Town	Atlanta
Entity Address, State or Province	GA
Entity Address, Postal Zip Code	30328
City Area Code	770
Local Phone Number	448-2193
Document Quarterly Report	true
Document Transition Report	false

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Income Statement [Abstract]
Net sales	$ 5,277.6	$ 5,382.1	$ 10,200.7	$ 10,334.3
Cost of goods sold	4,357.3	4,378.4	8,515.2	8,534
Gross profit	920.3	1,003.7	1,685.5	1,800.3
Selling, general and administrative expense excluding intangible amortization	498.9	493.1	978	946
Selling, general and administrative intangible amortization expense	86.2	88.1	172.8	176.1
(Gain) loss on disposal of assets	(8.6)	2.5	(10.3)	(11.4)
Multiemployer pension withdrawal income				(3.3)
Restructuring and other costs	444.7	363.4	477.7	365.7
Goodwill impairment	1,893		1,893
Operating (loss) profit	(1,993.9)	56.6	(1,825.7)	327.2
Interest expense, net	(108.4)	(72.5)	(205.7)	(159.2)
Loss on extinguishment of debt		(8.2)		(8.2)
Pension and other postretirement non-service (cost) income	(6)	39.7	(11)	79.6
Other (expense) income, net	(17.8)	6.3	7.4	6.5
Equity in income (loss) of unconsolidated entities	4.5	20.6	(31.5)	39
(Loss) income before income taxes	(2,121.6)	42.5	(2,066.5)	284.9
Income tax benefit (expense)	116.8	(1.8)	108.5	(60.4)
Consolidated net (loss) income	(2,004.8)	40.7	(1,958)	224.5
Less: Net income attributable to noncontrolling interests	(1.3)	(0.8)	(2.8)	(2.3)
Net (loss) income attributable to common stockholders	$ (2,006.1)	$ 39.9	$ (1,960.8)	$ 222.2
Basic (loss) earnings per share attributable to common stockholders	$ (7.85)	$ 0.15	$ (7.68)	$ 0.84
Diluted (loss) earnings per share attributable to common stockholders	$ (7.85)	$ 0.15	$ (7.68)	$ 0.83
Basic weighted average shares outstanding	255.6	263.4	255.2	264
Diluted weighted average shares outstanding	255.6	265.3	255.2	266.1

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Consolidated net (loss) income	$ (2,004.8)	$ 40.7	$ (1,958)	$ 224.5
Foreign currency translation adjustments:
Foreign currency translation gain	182.8	129.7	300.3	113.4
Recognition of previously unrealized foreign currency losses on consolidation of equity investment			29
Derivatives:
Deferred loss on cash flow hedges	(23.5)		(45.3)
Reclassification adjustment of net loss on cash flow hedges included in earnings	20.1		30
Defined benefit pension and other postretirement benefit plans:
Net actuarial gain arising during period		0.1		0.1
Amortization and settlement recognition of net actuarial loss, included in pension cost	10.1	1.5	19.8	2.8
Amortization and settlement recognition of prior service cost, included in pension cost	1.4	1.5	2.8	2.9
Other comprehensive income, net of tax	190.9	132.8	336.6	119.2
Comprehensive (loss) income	(1,813.9)	173.5	(1,621.4)	343.7
Less: Comprehensive income attributable to noncontrolling interests	(1.8)	(1.1)	(3.6)	(2.6)
Comprehensive (loss) income attributable to common stockholders	$ (1,815.7)	$ 172.4	$ (1,625)	$ 341.1

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions		Mar. 31, 2023	Sep. 30, 2022
Current assets:
Cash and cash equivalents		$ 363.4	$ 260.2
Accounts receivable (net of allowances of $67.0 and $66.3)		2,814.9	2,683.9
Inventories		2,550.3	2,317.1
Other current assets		1,700.5	689.8
Assets held for sale		169.2	34.4
Total current assets		7,598.3	5,985.4
Property, plant and equipment, net		11,163	10,081.4
Goodwill		4,253	5,895.2
Intangibles, net		2,759.1	2,920.6
Prepaid pension asset		463.4	440.3
Other noncurrent assets		1,973.6	3,082.6
Total Assets		28,210.4	28,405.5
Current liabilities:
Current portion of debt		501.6	212.2
Accounts payable		2,176.8	2,252.1
Accrued compensation and benefits		433.6	627.9
Other current liabilities		1,789.7	810.6
Liabilities held for sale		65.8
Total current liabilities		4,967.5	3,902.8
Long-term debt due after one year		9,004	7,575
Pension liabilities, net of current portion		212.7	189.4
Postretirement benefit liabilities, net of current portion		107.4	105.4
Deferred income taxes		2,605.7	2,761.9
Other noncurrent liabilities		1,644.1	2,445.8
Commitments and contingencies (Note 17)
Redeemable noncontrolling interests		7.9	5.5
Equity:
Preferred stock, $0.01 par value; 30.0 million shares authorized; no shares outstanding		0	0
Common Stock, $0.01 par value; 600.0 million shares authorized; 256.1 million and 254.4 million shares outstanding at March 31,2023 and September 30, 2022, respectively		2.6	2.5
Capital in excess of par value		10,649.3	10,639.4
Retained earnings		110	2,214.4
Accumulated other comprehensive loss	[1]	(1,118.5)	(1,454.3)
Total stockholders’ equity		9,643.4	11,402
Noncontrolling interests		17.7	17.7
Total equity		9,661.1	11,419.7
Total Liabilities and Equity		$ 28,210.4	$ 28,405.5
[1] All amounts are net of tax and noncontrolling interests.

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2023	Sep. 30, 2022
Statement of Financial Position [Abstract]
Allowance for Doubtful Accounts Receivable, Current	$ 67	$ 66.3
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	30,000,000	30,000,000
Preferred Stock, Shares Outstanding	0	0
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	600,000,000	600,000,000
Common Stock, Shares, Outstanding	256,100,000	254,400,000

CONSOLIDATED STATEMENTS OF EQUI

CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Millions		Total		Common Stock [Member]	Capital in Excess of Par Value [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interests [Member]
Beginning balance at Sep. 30, 2021				265,000,000
Beginning balance at Sep. 30, 2021				$ 2.7	$ 11,058.8	$ 1,607.9	$ (999.1)	$ 19.7	[1]
Compensation expense under share-based plans					39.7
Issuance of common stock, net of stock received for tax withholdings				1,500,000
Issuance of common stock, net of stock received for tax withholdings					(4.5)	(2)
Purchases of common stock		(7,200,000)		(7,200,000)
Purchases of common stock		$ (332.1)		$ (0.1)	(300.1)	(31.9)
Net (loss) income attributable to common stockholders						222.2
Dividends declared (per share - $0.275, $0.25, $0.55 and $0.50)	[2]					(133.7)
Other					(0.4)
Other comprehensive income, net of tax		118.9	[3]				118.9
Net loss		2.3						(0.5)	[1]
Distributions and adjustments to noncontrolling interests	[1]							(0.5)
Total Stockholders' equity at Mar. 31, 2022		11,578.4
Ending balance at Mar. 31, 2022				259,300,000
Ending balance at Mar. 31, 2022		11,597.1		$ 2.6	10,793.5	1,662.5	(880.2)	18.7	[1]
Beginning balance at Dec. 31, 2021				263,200,000
Beginning balance at Dec. 31, 2021				$ 2.6	10,996.1	1,711.2	(1,012.7)	20.1	[1]
Compensation expense under share-based plans					24.5
Issuance of common stock, net of stock received for tax withholdings				1,200,000
Issuance of common stock, net of stock received for tax withholdings					(13.2)	(1.8)
Purchases of common stock				(5,100,000)
Purchases of common stock					(213.9)	(20.7)
Net (loss) income attributable to common stockholders						39.9
Dividends declared (per share - $0.275, $0.25, $0.55 and $0.50)	[2]					(66.1)
Other comprehensive income, net of tax							132.5
Net loss		0.8						(0.9)	[1]
Distributions and adjustments to noncontrolling interests	[1]							(0.5)
Total Stockholders' equity at Mar. 31, 2022		11,578.4
Ending balance at Mar. 31, 2022				259,300,000
Ending balance at Mar. 31, 2022		$ 11,597.1		$ 2.6	10,793.5	1,662.5	(880.2)	18.7	[1]
Beginning balance at Sep. 30, 2022		254,400,000		254,400,000
Beginning balance at Sep. 30, 2022		$ 11,419.7		$ 2.5	10,639.4	2,214.4	(1,454.3)	17.7	[1]
Compensation expense under share-based plans					23.1
Issuance of common stock, net of stock received for tax withholdings				1,700,000
Issuance of common stock, net of stock received for tax withholdings				$ 0.1	(13.2)
Purchases of common stock		0
Net (loss) income attributable to common stockholders						(1,960.8)
Dividends declared (per share - $0.275, $0.25, $0.55 and $0.50)	[2]					(143.6)
Other comprehensive income, net of tax		$ 335.8	[3]				335.8
Net loss		2.8
Total Stockholders' equity at Mar. 31, 2023		$ 9,643.4
Ending balance at Mar. 31, 2023		256,100,000		256,100,000
Ending balance at Mar. 31, 2023		$ 9,661.1		$ 2.6	10,649.3	110	(1,118.5)	17.7	[1]
Beginning balance at Dec. 31, 2022				254,600,000
Beginning balance at Dec. 31, 2022				$ 2.5	10,652.6	2,188.3	(1,308.9)	17.8	[1]
Compensation expense under share-based plans					13.5
Issuance of common stock, net of stock received for tax withholdings				1,500,000
Issuance of common stock, net of stock received for tax withholdings				$ 0.1	(16.8)
Net (loss) income attributable to common stockholders						(2,006.1)
Dividends declared (per share - $0.275, $0.25, $0.55 and $0.50)	[2]					(72.2)
Other comprehensive income, net of tax							190.4
Net loss		1.3						(0.1)	[1]
Total Stockholders' equity at Mar. 31, 2023		$ 9,643.4
Ending balance at Mar. 31, 2023		256,100,000		256,100,000
Ending balance at Mar. 31, 2023		$ 9,661.1		$ 2.6	$ 10,649.3	$ 110	$ (1,118.5)	$ 17.7	[1]
[1] Excludes amounts related to contingently redeemable noncontrolling interests, which are separately classified outside of permanent equity on the consolidated balance sheets. Includes cash dividends and dividend equivalent units on certain equity awards. All amounts are net of tax and noncontrolling interests.

CONSOLIDATED STATEMENTS OF EQ_2

CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Statement of Stockholders' Equity [Abstract]
Cash dividends paid per share	$ 0.275	$ 0.25	$ 0.55	$ 0.50

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating activities:
Consolidated net (loss) income	$ (1,958)	$ 224.5
Adjustments to reconcile consolidated net income to net cash provided by operating activities:
Depreciation, depletion and amortization	769	740.1
Deferred income tax benefit	(239.6)	(100)
Share-based compensation expense	23.1	39.7
401(k) match and company contribution in common stock		2.5
Pension and other postretirement funding more than cost (income)	8.2	(67.3)
Cash surrender value increase in excess of premiums paid	(25.4)	(15)
Equity in loss (income) of unconsolidated entities	31.5	(39)
Gain on sale of businesses	(11.1)
Goodwill impairment	1,893
Other impairment adjustments	387.7	322.1
Gain on disposal of plant and equipment and other, net	(9.6)	(11.5)
Other, net	(14.3)	5.3
Change in operating assets and liabilities, net of acquisitions and divestitures:
Accounts receivable	170.3	(229.1)
Inventories	(44.8)	(133.4)
Other assets	(49.7)	(152.4)
Accounts payable	(214.3)	64.3
Income taxes	46.7	103
Accrued liabilities and other	(212.7)	(111.1)
Net cash provided by operating activities	550	642.7
Investing activities:
Capital expenditures	(563.7)	(354.1)
Cash paid for purchase of businesses, net of cash received	(853.5)	(7)
Proceeds from corporate owned life insurance	6.7	27.7
Proceeds from sale of businesses	25.9
Proceeds from currency forward contracts	23.2
Proceeds from sale of property, plant and equipment	18.7	23
Proceeds from property, plant and equipment insurance settlement		1.7
Other, net	(0.8)	2.1
Net cash used for investing activities	(1,343.5)	(306.6)
Financing activities:
Additions to revolving credit facilities	42.3
Repayments of revolving credit facilities	(116.3)	(40)
Additions to debt	1,379.1	375.1
Repayments of debt	(516.7)	(416.2)
Changes in commercial paper, net	291.4	224.6
Other debt (repayments) additions, net	(16.1)	4.8
Issuances of common stock, net of related tax withholdings	(16.3)	(9.2)
Purchases of common stock		(310.2)
Cash dividends paid to stockholders	(140.3)	(132.1)
Other, net	0.5	15.4
Net cash provided by (used for) financing activities	907.6	(287.8)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(2)	21
Changes in cash, cash equivalents and restricted cash in assets held-for-sale	(8.9)
Increase in cash, cash equivalents and restricted cash	103.2	69.3
Cash, cash equivalents and restricted cash at beginning of period	260.2	290.9
Cash, cash equivalents and restricted cash at end of period	$ 363.4	$ 360.2

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	6 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	Note 1. Basis of Presentation and Significant Accounting Policies Basis of Presentation Our independent registered public accounting firm has not audited the accompanying interim financial statements. We derived the consolidated balance sheet at September 30, 2022 from the audited consolidated financial statements included in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022 (the “ Fiscal 2022 Form 10-K ”). In the opinion of management, all normal recurring adjustments necessary for the fair presentation of the consolidated financial statements have been included for the interim periods reported. The interim financial statements have been prepared in accordance with accounting principles generally accepted in the U.S. (“ GAAP ”) for interim financial information and with Article 10 of Regulation S-X of the Securities and Exchange Commission (“ SEC ”). Accordingly, they omit certain notes and other information from the interim financial statements presented in this report. Therefore, these interim financial statements should be read in conjunction with the Fiscal 2022 Form 10-K. The results for the three and six months ended March 31, 2023 are not necessarily indicative of results that may be expected for the full year. On December 1, 2022 , we completed our previously announced acquisition of the remaining 67.7 % interest in Gondi, S.A. de C.V. (“ Grupo Gondi ”) for $ 969.8 million in cash and the assumption of debt (“ Grupo Gondi Acquisition ”). We have accounted for this acquisition as a business combination resulting in the consolidation of Grupo Gondi. See “ Note 3. Acquisitions ” for additional information. On December 1, 2022, we sold our Eaton, IN, and Aurora, IL uncoated recycled paperboard mills for $ 50 million, subject to a working capital adjustment. We received proceeds of $ 25 million, a preliminary working capital settlement of $ 0.9 million and are financing the remaining $ 25 million. Pursuant to the terms of the sale agreement, we transferred the control of these mills to the buyer and recorded a pre-tax gain on sale of $ 11.1 million recorded in Other (expense) income, net in our consolidated statements of operations. In November 2022, we announced our entry into a definitive agreement to divest our interior partitions converting operations (our ownership interest in RTS Packaging, LLC) and to sell our Chattanooga, TN uncoated recycled paperboard mill to our joint venture partner for $ 330 million, subject to a working capital adjustment. The transaction is expected to close in fiscal 2023 , subject to the satisfaction of closing conditions, including the receipt of regulatory approval. Accordingly, the related assets and liabilities have been reported in the consolidated balance sheet as of March 31, 2023 as assets and liabilities held for sale. See “ Note 4. Held for Sale ” for additional information. Reclassifications and Adjustments Certain amounts in prior periods have been reclassified to conform with the current year presentation. COVID-19 Pandemic The global impact of the COVID-19 pandemic (" COVID ") has affected our operational and financial performance to varying degrees. The extent of the effects of future public health crises, including a resurgence of COVID, or related containment measures and government responses are highly uncertain and cannot be predicted. Ransomware Incident As previously disclosed, on January 23, 2021 we detected a ransomware incident impacting certain of our systems. Promptly upon our detection of this incident, we initiated response and containment protocols and our security teams, supplemented by leading cyber defense firms, worked to remediate this incident. These actions included taking preventative measures, such as shutting down certain systems out of an abundance of caution, as well as taking steps to supplement existing security monitoring, scanning and protective measures. In our Form 10-Q for the second quarter of fiscal 2021, we announced that all systems were back in service. In the first and second quarters of fiscal 2022, we received additional business interruption recoveries of $ 5 million and $ 5 million, respectively, related to the ransomware incident, which we recorded as a reduction of Cost of goods sold and presented in net cash provided by operating activities on our consolidated statements of cash flows. See “ Note 1. Description of Business and Summary of Significant Accounting Policies — Ransomware Incident ” of the Notes to Consolidated Financial Statements section in the Fiscal 2022 Form 10-K for additional information, including recoveries ($ 15 million in fiscal 2021 and $ 57.2 million in fiscal 2022) and resiliency efforts and objectives. Significant Accounting Policies See “ Note 1. Description of Business and Summary of Significant Accounting Policies ” of the Notes to Consolidated Financial Statements section in the Fiscal 2022 Form 10-K for a summary of our significant accounting policies. Recent Accounting Developments New Accounting Standards — Recently Adopted In November 2021, the Financial Accounting Standards Board (“ FASB ”) issued Accounting Standards Update (“ ASU ”) 2021-10, “ Government Assistance (Topic 832) – Disclosures by Business Entities about Government Assistance ”. This ASU aims to increase the transparency of government assistance through the annual disclosure of the types of assistance, an entity’s accounting for the assistance and the effect of the assistance on an entity’s financial statements. This ASU is effective for annual periods beginning after December 15, 2021 (fiscal 2023 for us), with early adoption permitted. We adopted the provisions of ASU 2021-10 beginning October 1, 2022 . The adoption of this ASU did no t have a material impact on our consolidated financial statements. In October 2021, the FASB issued ASU 2021-08, “ Business Combinations (Topic 805) – Accounting for Contract Assets and Contract Liabilities from Contracts with Customers” . This ASU requires an entity to recognize and measure contract assets and contract liabilities acquired in a business combination in accordance with ASC 606 “ Revenue from Contracts with Customers ” (“ ASC 606 ”). This ASU aims to reduce diversity in practice and increase comparability for both the recognition and measurement of acquired revenue contracts with customers at the date of and after a business combination. This ASU is effective for fiscal years beginning after December 15, 2022 (fiscal 2024 for us), including interim periods therein, with early adoption permitted. We early adopted the provisions of ASU 2021-08 beginning October 1, 2022 . The adoption of this ASU did not have a material impact on our consolidated financial statements. In March 2020, the FASB issued ASU 2020-04, “ Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting ”. This ASU provides temporary optional expedients and exceptions for applying GAAP guidance on contract modifications and hedge accounting to ease the financial reporting burdens of the expected market transition from LIBOR and other interbank offered rates to alternative reference rates, such as the Secured Overnight Financing Rate. In January 2021, the FASB issued ASU 2021-01, which adds implementation guidance to clarify certain optional expedients in Topic 848. The ASUs could be adopted after their respective issuance dates through December 31, 2022. In December 2022, the FASB issued ASU 2022-06, “ Reference Rate Reform (Topic 848): Deferral of the Sunset Date of Topic 848 ”, which extends the period of time entities can utilize the reference rate reform relief guidance under ASU 2020-04 from December 31, 2022 to December 31, 2024. We are in the process of reviewing and updating our contracts to a new reference rate. We have been addressing the LIBOR transition in our applicable debt facilities and have completed the transition on all of our significant facilities. See “ Note 13. Debt ” of the Notes to Consolidated Financial Statements section in the Fiscal 2022 Form 10-K for additional information on our recent credit facility changes. We adopted the provisions of this optional guidance beginning October 1, 2022 . The adoption of these ASUs did no t have a material impact on our consolidated financial statements. New Accounting Standards — Recently Issued In March 2023, the FASB issued ASU 2023-01, “ Leases (Topic 842): Common Control Arrangements ”. This ASU requires all lessees to amortize leasehold improvements associated with common control leases over their useful life to the common control group and account for them as a transfer of assets between entities under common control at the end of the lease. This update is effective for fiscal years beginning after December 15, 2023 (fiscal 2025 for us), including interim periods therein, with early adoption permitted in any annual or interim period as of the beginning of the related fiscal year. We are evaluating the impact of this ASU. In September 2022, the FASB issued ASU 2022-04, “ Liabilities-Supplier Finance Programs (Subtopic 405-50): Disclosure of Supplier Finance Program Obligations ”. This ASU requires that all entities that use supplier finance programs in connection with the purchase of goods and services disclose sufficient information about the program to allow a user of financial statements to understand the program’s nature, activity during the period, changes from period to period, and potential magnitude. This ASU is effective for fiscal years beginning after December 15, 2022 (fiscal 2024 for us), except for the amendment on roll forward information, which is effective for fiscal years beginning after December 15, 2023 (fiscal 2025 for us), each with early adoption permitted. We are evaluating the impact of this ASU. In June 2022, the FASB issued ASU 2022-03, “ Fair Value Measurement (Topic 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions ”. This ASU clarifies that contractual sale restrictions should not be considered in measuring the fair value of equity securities. This ASU is effective for fiscal years beginning after December 15, 2023 (fiscal 2025 for us), including interim periods therein, with early adoption permitted. We are evaluating the impact of this ASU. In March 2022, the FASB issued ASU 2022-01, “ Derivatives and Hedging (Topic 815): Fair Value Hedging – Portfolio Layer Method ”. This ASU expands and clarifies the portfolio layer method for fair value hedges of interest rate risk. This ASU is effective for fiscal years beginning after December 15, 2022 (fiscal 2024 for us), including interim periods therein, with early adoption permitted. We are evaluating the impact of this ASU.

Revenue Recognition

Revenue Recognition	6 Months Ended
	Mar. 31, 2023
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Note 2. Revenue Recognition Disaggregated Revenue ASC 606 requires that we disaggregate revenue from contracts with customers into categories that depict how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors. The tables below disaggregate our revenue by geographical market and product type (segment). Net sales are attributed to geographical markets based on our selling location. See “ Note 8. Segment Information ” for additional information. The following tables summarize our disaggregated revenue by primary geographical markets (in millions): Three Months Ended March 31, 2023 Corrugated Packaging Consumer Packaging Global Paper Distribution Intersegment Total U.S. $ 2,001.6 $ 741.7 $ 1,056.3 $ 260.3 $ ( 84.6 ) $ 3,975.3 Canada 138.0 134.5 54.4 2.8 ( 1.8 ) 327.9 Latin America 485.0 12.5 35.1 44.2 ( 3.8 ) 573.0 EMEA (1) 2.8 304.5 11.4 — ( 0.2 ) 318.5 Asia Pacific — 71.9 11.0 — — 82.9 Total $ 2,627.4 $ 1,265.1 $ 1,168.2 $ 307.3 $ ( 90.4 ) $ 5,277.6 (1) Europe, Middle East and Africa ("EMEA") Six Months Ended March 31, 2023 Corrugated Packaging Consumer Packaging Global Paper Distribution Intersegment Sales Total U.S. $ 3,975.1 $ 1,444.7 $ 2,079.0 $ 537.0 $ ( 156.1 ) $ 7,879.7 Canada 275.1 258.2 99.9 6.2 ( 3.3 ) 636.1 Latin America 710.5 64.2 68.7 85.6 ( 5.1 ) 923.9 EMEA 4.1 564.4 22.5 — ( 0.3 ) 590.7 Asia Pacific — 148.6 21.7 — — 170.3 Total $ 4,964.8 $ 2,480.1 $ 2,291.8 $ 628.8 $ ( 164.8 ) $ 10,200.7 Three Months Ended March 31, 2022 Corrugated Packaging Consumer Packaging Global Paper Distribution Intersegment Total U.S. $ 2,068.1 $ 720.0 $ 1,376.3 $ 319.1 $ ( 85.8 ) $ 4,397.7 Canada 145.9 128.4 62.2 3.8 ( 2.0 ) 338.3 Latin America 104.7 48.3 65.0 39.4 ( 0.1 ) 257.3 EMEA 0.3 277.0 17.6 — — 294.9 Asia Pacific — 76.9 17.0 — — 93.9 Total $ 2,319.0 $ 1,250.6 $ 1,538.1 $ 362.3 $ ( 87.9 ) $ 5,382.1 Six Months Ended March 31, 2022 Corrugated Packaging Consumer Packaging Global Paper Distribution Intersegment Sales Total U.S. $ 4,037.1 $ 1,368.3 $ 2,589.4 $ 603.7 $ ( 168.2 ) $ 8,430.3 Canada 286.3 242.7 120.1 7.3 ( 3.3 ) 653.1 Latin America 212.3 93.8 113.3 76.1 ( 0.2 ) 495.3 EMEA 3.3 529.1 33.5 — ( 0.1 ) 565.8 Asia Pacific — 155.4 34.4 — — 189.8 Total $ 4,539.0 $ 2,389.3 $ 2,890.7 $ 687.1 $ ( 171.8 ) $ 10,334.3 Revenue Contract Balances Contract assets are rights to consideration in exchange for goods that we have transferred to a customer when that right is conditional on something other than the passage of time. Contract assets are reduced when the control of the goods passes to the customer. Contract liabilities represent obligations to transfer goods or services to a customer for which we have received consideration. Contract liabilities are reduced once control of the goods is transferred to the customer. The opening and closing balances of our contract assets and contract liabilities are as follows. Contract assets and contract liabilities are reported within Other current assets and Other current liabilities, respectively, on the consolidated balance sheets (in millions). Contract Assets Contract Liabilities Beginning balance - October 1, 2022 $ 244.0 $ 13.9 Increase (decrease) 13.9 ( 1.6 ) Ending balance - March 31, 2023 $ 257.9 $ 12.3

Acquisitions

Acquisitions	6 Months Ended
	Mar. 31, 2023
Business Combinations [Abstract]
Acquisitions	Note 3. Acquisitions When we obtain control of a business by acquiring its net assets, or some or all of its equity interest, we account for those acquisitions in accordance with ASC 805, “ Business Combinations ”. The estimated fair values of all assets acquired and liabilities assumed in acquisitions are provisional and may be revised as a result of additional information obtained during the measurement period of up to one year from the acquisition date. Grupo Gondi Acquisition On December 1, 2022 , we completed our previously announced acquisition of the remaining 67.7 % interest in Grupo Gondi. Grupo Gondi is a leading integrated producer of fiber-based sustainable packaging solutions that operates four paper mills, nine corrugated packaging plants and six high graphic plants throughout Mexico, producing sustainable packaging for a wide range of end markets in the region. This tuck-in acquisition is expected to provide us with further geographic and end market diversification as well as position us to continue to grow in the attractive Latin American market. See below for a summary of the purchase consideration transferred as defined under ASC 805 (in millions): Purchase Cash consideration transferred for 67.7 % interest $ 969.8 Fair value of the previously held interest 403.7 Settlement of preexisting relationships (net receivable 40.2 Purchase consideration transferred $ 1,413.7 In connection with the transaction, in the first quarter of fiscal 2023 we recognized a $ 46.8 million non-cash, pre-tax loss (or $ 24.6 million after release of a related deferred tax liability) on our original 32.3 % investment. The loss is reflected in the Equity in income (loss) of unconsolidated entities line item in our consolidated statements of operations and included the write-off of historical foreign currency translation adjustments previously recorded in Accumulated other comprehensive loss in our consolidated balance sheet , as well as the difference between the fair value of the consideration paid and the carrying value of our prior ownership interest. The fair value of our previously held interest in Grupo Gondi was estimated to be $ 403.7 million at the acquisition date based on the cash consideration exchanged for acquiring the 67.7 % of equity interest adjusted for the deemed payment of a control premium. This step-acquisition provided us with 100 % control of Grupo Gondi and we met the other requirements under ASC 805 to be accounted for using the acquisition method of accoun ting. We have included the financial results of the acquired operations in our Corrugated Packaging segment. Post acquisition, sales to Grupo Gondi are eliminated from Global Paper results. The following table summarizes the preliminary fair values of the assets acquired and liabilities assumed in the Grupo Gondi Acquisition by major class of assets and liabilities as of the acquisition date, as well as adjustments made during fiscal 2023 (referred to as “measurement period adjustments”) (in millions): Amounts Recognized as of the Acquisition Date Measurement Period Adjustments (1) Amounts Recognized as of Acquisition Date (as Adjusted) (2) Cash and cash equivalents $ 116.3 $ — $ 116.3 Current assets, excluding cash and cash equivalents 697.0 ( 1.6 ) 695.4 Property, plant and equipment 1,380.3 15.2 1,395.5 Goodwill 231.2 2.1 233.3 Other noncurrent assets 101.4 ( 0.1 ) 101.3 Total assets acquired 2,526.2 15.6 2,541.8 Current portion of debt (3) 13.2 0.5 13.7 Current liabilities, excluding debt 384.8 0.4 385.2 Long-term debt due after one year (3) 591.4 14.7 606.1 Pension liabilities, net of current portion 35.2 — 35.2 Deferred income taxes 69.8 — 69.8 Other noncurrent liabilities 18.1 — 18.1 Total liabilities assumed 1,112.5 15.6 1,128.1 Net assets acquired $ 1,413.7 $ — $ 1,413.7 (1) The measurement period adjustments recorded in fiscal 2023 did not have a significant impact on our consolidated statements of operations for the three and six months ended March 31, 2023. (2) The measurement period adjustments were primarily due to refinements to the carrying amounts of certain assets and liabilities. The net impact of the measurement period adjustments resulted in a net increase in goodwill. (3) Includes $ 494.8 million of Grupo Gondi debt that we assumed and repa id in connection with th e closing of the Grupo Gondi Acquisition. The remaining balance relates to current and long-term portions of finance leases. We continue to analyze the estimated values of all assets acquired and liabilities assumed including, among other things, finalizing third-party valuations; therefore, the allocation of the purchase price remains preliminary and subject to revision. Goodwill is calculated as the excess of the consideration transferred over the net assets recognized and represents the estimated future economic benefits arising from other assets acquired that could not be individually identified and separately recognized. The fair value assigned to goodwill is primarily attributable to buyer-specific synergies expected to arise after the acquisition (e.g., enhanced reach of the combined organization and other synergies), the assembled work force, as well as due to establishing deferred tax liabilities for the difference between book and tax basis of the assets and liabilities acquired. The goodwill is not amortizable for income tax purposes. Transaction costs to acquire Grupo Gondi are expensed as incurred and recorded within Restructuring and other costs. See “ Note 5. Restructuring and Other Costs ” for additional information.

Held For Sale

Held For Sale	6 Months Ended
	Mar. 31, 2023
Disposal Group, Including Discontinued Operation, Assets [Abstract]
Held For Sale	Note 4. Held For Sale In November 2022, we announced our entry into a definitive agreement to divest our interior partitions converting operations (our ownership interest in RTS Packaging, LLC) and to sell our Chattanooga, TN uncoated recycled paperboard mill to our joint venture partner for $ 330 million, subject to a working capital adjustment. The transaction is expected to close in fiscal 2023 , subject to the satisfaction of closing conditions, including the receipt of regulatory approval. Accordingly, the related assets and liabilities have been reported in the consolidated balance sheet as of March 31, 2023 as assets and liabilities held for sale. We discontinued recording depreciation and amortization while the assets are held for sale. We have also measured the disposal groups classified as held for sale at the lower of their carrying amount or fair value less cost to sale, noting no impairment. We determined that the disposal groups classified as held for sale do not meet the criteria for classification as discontinued operations. Net assets and liabilities held for sale at March 31, 2023 and September 30, 2022 were $ 103.4 million and $ 34.4 million, respectively. Net assets held for sale at March 31, 2023 , include $ 71.1 million for the divestiture outlined above and $ 32.3 million related to closed facilities. The net assets held for sale at March 31, 2023 associated with the divestiture consisted primarily of $ 42.0 million of property, plant and equipment, net and $ 24.9 million of goodwill. N et assets held for sale of $ 34.4 million at September 30, 2022 were related to closed facilities .

Restructuring and Other Costs

Restructuring and Other Costs	6 Months Ended
	Mar. 31, 2023
Restructuring And Other Costs [Abstract]
Restructuring and Other Costs	Note 5. Restructuri ng and Other Costs Summary of Restructuring and Other Initiatives We recorded pre-tax restructuring and other costs of $ 444.7 million and $ 477.7 million for the three and six months ended March 31, 2023, respectively, and $ 363.4 million and $ 365.7 million for the three and six months ended March 31, 2022 , respectively. Of these costs, $ 346.5 million and $ 322.1 million for the six months ended March 31, 2023 and 2022, respectively were non-cash. These amounts are not comparable since the timing and scope of the individual actions associated with each restructuring, acquisition, integration or divestiture can vary. We present our restructuring and other costs in more detail below. The following table summarizes our Restructuring and other costs (in millions): Three Months Ended Six Months Ended March 31, March 31, 2023 2022 2023 2022 Restructuring $ 441.2 $ 362.9 $ 457.5 $ 365.0 Other 3.5 0.5 20.2 0.7 Restructuring and other costs $ 444.7 $ 363.4 $ 477.7 $ 365.7 Restructuring Our restructuring charges are primarily associated with restructuring portions of our operations (i.e., partial or complete facility closures). A partial facility closure may consist of shutting down a machine and/or a workforce reduction. We have previously incurred reduction in workforce actions, facility closure activities, impairment costs and certain lease or other contract terminations. We are committed to improving our return on invested capital as well as maximizing the performance of our assets. In the second quarter of fiscal 2023, we recorded charges of $ 415.3 million associated with our decision to permanently cease operations at our North Charleston, SC containerboard mill. We expect to cease operations on August 31, 2023. These charges are included in the table below in the Global Paper segment. We expect to record future restructuring charges, primarily associated with carrying costs and contract terminations. The mill’s annual production capacity was 550,000 tons, approximately two-thirds of which was shipped to external customers of the Global Paper segment. The remaining one-third of the mill’s production was utilized internally at our converting plants in our Corrugated Packaging segment. The mill’s operations were expected to require significant capital investment to maintain and improve going forward. By closing this mill, significant capital that would have been required to keep the mill competitive in the future is expected to be deployed to improve key assets. The table below also includes various impairments and other charges, including $ 355.1 million associated with our second quarter of fiscal 2022 decision to permanently cease operations at our Panama City, FL mill. In addition, the table reflects the fourth quarter of fiscal 2022 decision to permanently close the corrugated medium manufacturing operations at the St. Paul, MN mill. In the second quarter of fiscal 2022, we cancelled our plans to shut down a bleached paperboard machine at our Evadale, TX mill and reversed certain employee and other accrued restructuring charges. See “ Note 4. Restructuring and Other Costs ” of the Notes to Consolidated Financial Statements section in the Fiscal 2022 Form 10-K for additional information. While restructuring costs are not charged to our segments and, therefore, do not reduce each segment's Adjusted EBITDA (as hereinafter defined), we highlight the segment to which the charges relate. Since we do not allocate restructuring costs to our segments, charges incurred in the Global Paper segment will represent all charges associated with our vertically integrated mills and recycling operations. These operations manufacture for the benefit of each reportable segment that ultimately sells the associated paper and packaging products to our external customers. The following table presents a summary of restructuring charges related to active restructuring initiatives that we incurred during the three and six months ended March 31, 2023 and 2022, the cumulative recorded amount since we started the initiatives and our estimate of the total we expect to incur, which is subject to a number of assumptions and actual results may differ (in millions): Three Months Ended Six Months Ended March 31, March 31, 2023 2022 2023 2022 Cumulative Total Corrugated Packaging PP&E and related costs $ 4.3 $ — $ 4.3 $ — $ 8.0 $ 8.0 Severance and other employee costs 3.6 4.4 5.3 4.0 15.0 15.0 Other restructuring costs 0.1 0.1 0.2 0.4 6.3 12.2 Restructuring total $ 8.0 $ 4.5 $ 9.8 $ 4.4 $ 29.3 $ 35.2 Consumer Packaging PP&E and related costs $ — $ — $ — $ — $ 2.2 $ 2.2 Severance and other employee costs 2.2 1.3 8.6 3.1 33.5 33.5 Other restructuring costs ( 0.2 ) 0.1 ( 0.5 ) 0.1 9.8 9.8 Restructuring total $ 2.0 $ 1.4 $ 8.1 $ 3.2 $ 45.5 $ 45.5 Global Paper PP&E and related costs $ 344.0 $ 344.4 $ 342.9 $ 344.4 $ 715.3 $ 715.3 Severance and other employee costs 19.3 10.7 19.1 10.7 30.5 39.8 Other restructuring costs 63.0 — 69.0 — 85.2 232.1 Restructuring total $ 426.3 $ 355.1 $ 431.0 $ 355.1 $ 831.0 $ 987.2 Distribution Severance and other employee costs $ 1.0 $ — $ 1.0 $ — $ 1.1 $ 1.1 Other restructuring costs 0.1 — 0.1 — 1.1 1.1 Restructuring total $ 1.1 $ — $ 1.1 $ — $ 2.2 $ 2.2 Corporate PP&E and related costs $ 0.2 $ 0.3 $ 0.6 $ 1.2 $ 11.4 $ 11.4 Severance and other employee costs 1.7 — 3.9 — 7.8 7.8 Other restructuring costs 1.9 1.6 3.0 1.1 7.5 7.5 Restructuring total $ 3.8 $ 1.9 $ 7.5 $ 2.3 $ 26.7 $ 26.7 Total PP&E and related costs $ 348.5 $ 344.7 $ 347.8 $ 345.6 $ 736.9 $ 736.9 Severance and other employee costs 27.8 16.4 37.9 17.8 87.9 97.2 Other restructuring costs 64.9 1.8 71.8 1.6 109.9 262.7 Restructuring total $ 441.2 $ 362.9 $ 457.5 $ 365.0 $ 934.7 $ 1,096.8 We define “ PP&E and related costs ” as used in this Note 5 primarily as property, plant and equipment write-downs, subsequent adjustments to fair value for assets classified as held for sale, subsequent (gains) or losses on sales of property, plant and equipment, related parts and supplies on such assets, and deferred major maintenance costs, if any. We define " Other restructuring costs " as facility carrying costs, equipment and inventory relocation costs, lease or other contract termination costs, and other items, including impaired intangibles attributable to our restructuring actions. Other Costs Our other costs consist of acquisition, integration and divestiture costs. We incur costs when we acquire or divest businesses. Acquisition costs include costs associated with transactions, whether consummated or not, such as advisory, legal, accounting, valuation and other professional or consulting fees, as well as litigation costs associated with those activities. We incur integration costs pre- and post-acquisition that reflect work performed to facilitate merger and acquisition integration, such as work associated with information systems and other projects including spending to support future acquisitions, and such costs primarily consist of professional services and labor. Divestiture costs consist primarily of similar professional fees. We consider acquisition, integration and divestiture costs to be corporate costs regardless of the segment or segments involved in the transaction. The following table presents our acquisition, integration and divestiture costs (in millions): Three Months Ended Six Months Ended March 31, March 31, 2023 2022 2023 2022 Acquisition costs $ 1.2 $ 0.2 $ 12.2 $ 0.4 Integration costs 1.8 0.2 6.1 0.2 Divestiture costs 0.5 0.1 1.9 0.1 Other total $ 3.5 $ 0.5 $ 20.2 $ 0.7 Acquisition costs in the table above include transaction costs related to the acquisition of the remaining interest in Grupo Gondi, as well as other matters. Accruals The following table summarizes the changes in the restructuring accrual, which is primarily composed of accrued severance and other employee costs, and a reconciliation of the restructuring accrual charges to the line item “ Restructuring and other costs ” on our consolidated statements of operations (in millions): Six Months Ended March 31, 2023 2022 Accrual at beginning of fiscal year $ 25.2 $ 13.4 Additional accruals 40.2 17.6 Payments ( 18.9 ) ( 4.0 ) Adjustment to accruals ( 2.5 ) ( 0.3 ) Accrual at March 31 $ 44.0 $ 26.7 Reconciliation of accruals and charges to restructuring and other costs (in millions): Six Months Ended March 31, 2023 2022 Additional accruals and adjustments to accruals $ 37.7 $ 17.3 PP&E and related costs 347.8 345.6 Severance and other employee costs 0.2 0.5 Acquisition costs 12.2 0.4 Integration costs 6.1 0.2 Divestiture costs 1.9 0.1 Other restructuring costs 71.8 1.6 Total restructuring and other costs $ 477.7 $ 365.7

Retirement Plans

Retirement Plans	6 Months Ended
	Mar. 31, 2023
Retirement Plans [Abstract]
Retirement Plans	Note 6. Retirement Plans We have defined benefit pension plans and other postretirement benefit plans for certain U.S. and non-U.S. employees. Certain plans were frozen for salaried and non-union hourly employees at various times in the past, and nearly all of our remaining U.S. salaried and U.S. non-union hourly employees accruing benefits ceased accruing benefits as of December 31, 2020. In addition, we participate in several multiemployer pension plans (“ MEPP ” or “ MEPPs ”) that provide retirement benefits to certain union employees in accordance with various collective bargaining agreements and have participated in other MEPPs in the past. We also have supplemental executive retirement plans and other non-qualified defined benefit pension plans that provide unfunded supplemental retirement benefits to certain of our current and former executives. See “ Note 5. Retirement Plans ” of the Notes to Consolidated Financial Statements section in the Fiscal 2022 Form 10-K for more information regarding our involvement with retirement plans. MEPPs In the normal course of business, we evaluate our potential exposure to MEPPs, including potential withdrawal liabilities. In fiscal 2018, we submitted formal notification to withdraw from the Pace Industry Union-Management Pension Fund (“ PIUMPF ”) and recorded a withdrawal liability and a liability for our proportionate share of PIUMPF’s accumulated funding deficiency. Subsequently, in fiscal 2019 and 2020, we received demand letters from PIUMPF, including a demand for withdrawal liabilities and for our proportionate share of PIUMPF's accumulated funding deficiency. In July 2021, PIUMPF filed suit against us in the U.S. District Court for the Northern District of Georgia claiming the right to recover our pro rata share of the pension fund’s accumulated funding deficiency along with interest, liquidated damages and attorney's fees. We believe we are adequately reserved for this matter. See “ Note 5. Retirement Plans — Multiemployer Plans ” of the Notes to Consolidated Financial Statements section in the Fiscal 2022 Form 10-K for additional information on our MEPPs and see “ Note 17. Commitments and Contingencies — Other Litigation ” for additional information on the litigation. At March 31, 2023 and September 30, 2022, we had recorded withdrawal liabilities of $ 213.1 million and $ 214.7 million, respectively, including liabilities associated with PIUMPF's accumulated funding deficiency demands. Pension and Postretirement Cost (Income) The following table presents a summary of the components of net pension cost (income) (in millions): Three Months Ended Six Months Ended March 31, March 31, 2023 2022 2023 2022 Service cost $ 7.9 $ 12.7 $ 15.4 $ 25.2 Interest cost 64.4 47.3 128.1 94.7 Expected return on plan assets ( 75.5 ) ( 92.5 ) ( 151.3 ) ( 185.0 ) Amortization of net actuarial loss 14.7 2.2 29.2 4.4 Amortization of prior service cost 1.9 2.1 4.0 4.2 Settlement loss — 0.2 — 0.2 Company defined benefit plan cost (income) 13.4 ( 28.0 ) 25.4 ( 56.3 ) Multiemployer and other plans 0.4 0.4 0.7 0.7 Net pension cost (income) $ 13.8 $ ( 27.6 ) $ 26.1 $ ( 55.6 ) The non-service elements of our pension and postretirement cost set forth in this Note 6 are reflected in the consolidated statements of operations line item “Pension and other postretirement non-service (cost) income”. The service cost components are reflected in “Cost of goods sold” and “Selling, general and administrative expense excluding intangible amortization” line items. We maintain other postretirement benefit plans that provide certain health care and life insurance benefits for certain salaried and hourly employees who meet specified age and service requirements as defined by the plans. The following table presents a summary of the components of the net postretirement cost (in millions): Three Months Ended Six Months Ended March 31, March 31, 2023 2022 2023 2022 Service cost $ 0.2 $ 0.2 $ 0.4 $ 0.5 Interest cost 1.8 1.6 3.6 3.1 Amortization of net actuarial gain ( 1.2 ) ( 0.4 ) ( 2.3 ) ( 0.8 ) Amortization of prior service credit ( 0.1 ) ( 0.2 ) ( 0.3 ) ( 0.4 ) Net postretirement cost $ 0.7 $ 1.2 $ 1.4 $ 2.4 Employer Contributions During the three and six months ended March 31, 2023 , we made contributions to our qualified and supplemental defined benefit pension plans of $ 7.4 million and $ 15.0 million , respectively, and for the three and six months ended March 31, 2022 we made contributions of $ 6.2 million and $ 10.3 million, respectively . During the three and six months ended March 31, 2023, we funded an aggregate of $ 2.1 million and $ 3.6 million, respectively, to our other postretirement benefit plans and for the three and six months ended March 31, 2022 we funded an aggregate of $ 1.9 million and $ 3.1 million, respectively.

Income Taxes

Income Taxes	6 Months Ended
	Mar. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Note 7. Income Taxes The effective tax rate for the three and six months ended March 31, 2023 was 5.5 % and 5.3 % , respectively. The effective tax rates were impacted by (i) the tax effects of the goodwill impairment, (ii) the tax effects related to the Grupo Gondi Acquisition (iii) research and development and other tax credits (iv) the inclusion of state taxes, (v) income derived from certain foreign jurisdictions subject to higher tax rates and (vi) the exclusion of tax benefits related to losses recorded by certain foreign operations. The effective tax rate for the three and six months ended March 31, 2022 was 4.2 % and 21.2 % , respectively. The effective tax rates were impacted by (i) research and development tax credits, partially offset by (ii) the inclusion of state taxes, (iii) income derived from certain foreign jurisdictions subject to higher tax rates and (iv) the exclusion of tax benefits related to losses recorded by certain foreign operations. The lower tax rate in the three months ended March 31, 2022 was primarily due to the disproportionate impact of research and development tax credits due to reduced pre-tax income as a result of restructuring and other costs in the period. During the six months ended March 31, 2023 and March 31, 2022, cash paid for income taxes, net of refunds, was $ 86.2 million and $ 55.8 million, respectively.

Segment Information

Segment Information	6 Months Ended
	Mar. 31, 2023
Segment Reporting [Abstract]
Segment Information	Note 8. Segment Information We report our financial results of operations in the following four reportable segments: • Corrugated Packaging , which substantially consists of our integrated corrugated converting operations and generates its revenues primarily from the sale of corrugated containers and other corrugated products, including the acquired Grupo Gondi operations; • Consumer Packaging , which consists of our integrated consumer converting operations and generates its revenues primarily from the sale of consumer packaging products such as folding cartons, interior partitions and other consumer products; • Global Paper , which consists of our commercial paper operations and generates its revenues primarily from the sale of containerboard and paperboard to external customers; and • Distribution , which consists of our distribution and display assembly operations and generates its revenues primarily from the distribution of packaging products and assembly of display products. Due to the timing of the Grupo Gondi Acquisition, it was not practicable to allocate the results of Grupo Gondi to our operating segments for the first quarter of fiscal 2023. As a result, we included the results for December 2022 in "Other unallocated". In the second quarter of fiscal 2023, we finalized our segment reporting assessment and included the results of the Grupo Gondi operations in our Corrugated Packaging segment, which is consistent with our internal operational structure and how the Company’s chief operating decision maker (" CODM ") allocates resources and assesses financial performance. See “ Note 3. Acquisitions ” for additional information. As part of this assessment, we also moved certain existing consumer converting operations in Latin America into our Corrugated Packaging segment in line with how we are managing the business effective January 1, 2023. We did not recast prior year results related to these operations as they were not material. Grupo Gondi results for the month of December have been recast and are reflected in the Corrugated Packaging segment. We determined our operating segments based on the products and services we offer. Our operating segments are consistent with our internal management structure, and we do not aggregate operating segments. We report the benefit of vertical integration with our mills in each reportable segment that ultimately sells the associated paper and packaging products to our external customers. We account for intersegment sales at prices that approximate market prices. Adjusted EBITDA is our measure of segment profitability in accordance with ASC 280, “ Segment Reporting ” because it is used by our CODM to make decisions regarding allocation of resources and to assess segment performance. Certain items are not allocated to our operating segments and, thus, the information that our CODM uses to make operating decisions and assess performance does not reflect such amounts. Adjusted EBITDA is defined as pre-tax earnings of a reportable segment before depreciation, depletion and amortization, and excludes the following items our CODM does not consider part of our segment performance: gain on sale of certain closed facilities, multiemployer pension withdrawal income, restructuring and other costs, goodwill impairment, non-allocated expenses, interest expense, net, loss on extinguishment of debt, other (expense) income, net, and other adjustments - each as outlined in the table below (" Adjusted EBITDA "). Management believes excluding these items is useful in the evaluation of operating performance from period to period because these items are not representative of our ongoing operations or are items our CODM does not consider part of our reportable segments. The tables in this Note 8 show selected financial data for our reportable segments (in millions): Three Months Ended Six Months Ended March 31, March 31, 2023 2022 2023 2022 Net sales (aggregate): Corrugated Packaging $ 2,627.4 $ 2,319.0 $ 4,964.8 $ 4,539.0 Consumer Packaging 1,265.1 1,250.6 2,480.1 2,389.3 Global Paper 1,168.2 1,538.1 2,291.8 2,890.7 Distribution 307.3 362.3 628.8 687.1 Total $ 5,368.0 $ 5,470.0 $ 10,365.5 $ 10,506.1 Less net sales (intersegment): Corrugated Packaging $ 81.6 $ 78.5 $ 150.0 $ 152.7 Consumer Packaging 7.5 6.9 12.2 12.9 Distribution 1.3 2.5 2.6 6.2 Total $ 90.4 $ 87.9 $ 164.8 $ 171.8 Net sales (unaffiliated customers): Corrugated Packaging $ 2,545.8 $ 2,240.5 $ 4,814.8 $ 4,386.3 Consumer Packaging 1,257.6 1,243.7 2,467.9 2,376.4 Global Paper 1,168.2 1,538.1 2,291.8 2,890.7 Distribution 306.0 359.8 626.2 680.9 Total $ 5,277.6 $ 5,382.1 $ 10,200.7 $ 10,334.3 Adjusted EBITDA: Corrugated Packaging $ 407.5 $ 328.7 $ 736.9 $ 617.6 Consumer Packaging 218.6 205.8 401.9 375.1 Global Paper 187.1 308.6 344.4 541.0 Distribution 9.3 28.0 20.1 34.5 Total 822.5 871.1 1,503.3 1,568.2 Depreciation, depletion and amortization ( 395.8 ) ( 373.6 ) ( 769.0 ) ( 740.1 ) Gain on sale of certain closed facilities 8.9 — 9.8 14.4 Multiemployer pension withdrawal income — — — 3.3 Restructuring and other costs ( 444.7 ) ( 363.4 ) ( 477.7 ) ( 365.7 ) Goodwill impairment ( 1,893.0 ) — ( 1,893.0 ) — Non-allocated expenses ( 33.9 ) ( 17.2 ) ( 62.6 ) ( 34.0 ) Interest expense, net ( 108.4 ) ( 72.5 ) ( 205.7 ) ( 159.2 ) Loss on extinguishment of debt — ( 8.2 ) — ( 8.2 ) Other (expense) income, net ( 17.8 ) 6.3 7.4 6.5 Other adjustments ( 59.4 ) — ( 179.0 ) ( 0.3 ) (Loss) income before income taxes $ ( 2,121.6 ) $ 42.5 $ ( 2,066.5 ) $ 284.9 Additional selected financial data (in millions): Three Months Ended Six Months Ended March 31, March 31, 2023 2022 2023 2022 Depreciation, depletion and amortization: Corrugated Packaging $ 211.2 $ 166.9 $ 403.4 $ 333.9 Consumer Packaging 85.5 90.1 169.6 176.4 Global Paper 91.2 109.8 180.3 216.0 Distribution 6.9 5.8 13.8 11.6 Corporate 1.0 1.0 1.9 2.2 Total $ 395.8 $ 373.6 $ 769.0 $ 740.1 Other adjustments: Corrugated Packaging $ 4.7 $ ( 6.4 ) $ 54.5 $ ( 6.4 ) Consumer Packaging 28.0 7.5 59.6 7.7 Global Paper 9.1 ( 1.1 ) 26.6 ( 1.0 ) Corporate 17.6 — 38.3 — Total $ 59.4 $ — $ 179.0 $ 0.3 Equity in income (loss) of unconsolidated entities: Corrugated Packaging $ 4.0 $ 20.6 $ ( 31.8 ) $ 35.6 Consumer Packaging — — — 3.4 Global Paper 0.5 — 0.3 — Total $ 4.5 $ 20.6 $ ( 31.5 ) $ 39.0 Other adjustments in the table above for the three months ended March 31, 2023 consist primarily of: • incremental work stoppage costs at our Mahrt mill of $ 27.2 million pre-tax in the Consumer Packaging segment and $ 9.0 million pre-tax in the Global Paper segment, • business systems transformation costs in Corporate of $ 17.5 million, and • acquisition accounting inventory-related adjustments of $ 4.6 million in Corrugated Packaging. Other adjustments in the table above for the six months ended March 31, 2023 consist primarily of: • a $ 46.8 mil lion non-cash, pre-tax loss in the Corrugated Packaging segment related to Grupo Gondi as discussed in “ Note 3. Acquisitions ”, • incremental work stoppage costs at our Mahrt mill of $ 58.5 million pre-tax in the Consumer Packaging segment and $ 19.3 million pre-tax in the Global Paper segment, • business systems transformation costs in Corporate of $ 37.7 million, and • acquisition accounting inventory-related adjustments of $ 7.6 million and $ 5.5 million in the Corrugated Packaging and Global Paper segments, respectively. See “ Note 5. Restructuring and Other Costs” for additional information on how the Restructuring and other costs relate to our reportable segments. We allocate the assets and capital expenditures of our mill system across our reportable segments because the benefits of vertical integration are reflected in the reportable segment that ultimately sells the associated paper and packaging products to external customers. The following tables reflect such allocation (in millions): March 31, September 30, Assets: Corrugated Packaging $ 13,066.0 $ 11,382.5 Consumer Packaging 6,647.0 6,704.5 Global Paper 5,151.1 7,039.2 Distribution 813.5 863.0 Assets held for sale 169.2 34.4 Corporate 2,363.6 2,381.9 Total $ 28,210.4 $ 28,405.5 Intangibles, net: Corrugated Packaging $ 608.2 $ 648.4 Consumer Packaging 1,460.9 1,523.5 Global Paper 563.8 612.6 Distribution 126.2 136.1 Total $ 2,759.1 $ 2,920.6 Equity method investments: Corrugated Packaging $ 78.6 $ 479.3 Consumer Packaging 0.6 0.5 Global Paper 1.2 0.5 Corporate 0.1 0.1 Total $ 80.5 $ 480.4 The decrease in equity method investments compared to September 30, 2022, was due to the Grupo Gondi Acquisition in December 2022. See “ Note 3. Acquisitions ” for additional information. Six Months Ended March 31, 2023 2022 Capital expenditures: Corrugated Packaging $ 241.7 $ 156.7 Consumer Packaging 125.5 67.9 Global Paper 144.1 108.8 Distribution 7.6 2.5 Corporate 44.8 18.2 Total $ 563.7 $ 354.1 The changes in the carrying amount of goodwill during the six months ended March 31, 2023 are as follows (in millions): Corrugated Consumer Global Paper Distribution Total Balance as of Sep. 30, 2022 $ 2,802.8 $ 1,588.4 $ 1,366.5 $ 137.5 $ 5,895.2 Goodwill impairment ( 514.3 ) — ( 1,378.7 ) — ( 1,893.0 ) Acquisitions 233.3 — — — 233.3 Divestitures — ( 7.4 ) ( 4.1 ) — ( 11.5 ) Transferred to assets held for sale — ( 24.9 ) — — ( 24.9 ) Translation and other adjustments 71.9 ( 35.4 ) 16.3 1.1 53.9 Balance as of Mar. 31, 2023 Goodwill $ 3,108.0 $ 1,520.7 $ 1,378.7 $ 138.6 $ 6,146.0 Accumulated impairment losses ( 514.3 ) — ( 1,378.7 ) — ( 1,893.0 ) $ 2,593.7 $ 1,520.7 $ - $ 138.6 $ 4,253.0 We review the carrying value of our goodwill annually at the beginning of the fourth quarter of each fiscal year, or more often if events or changes in circumstances indicate that the carrying amount may exceed fair value. Due to the sustained decrease in our market capitalization and the further deterioration of macroeconomic conditions, including the impact of soft demand, pricing pressure and elevated inflation, which negatively affected our long-term forecasts in certain segments, we concluded that impairment indicators existed for the second quarter of fiscal 2023. As a result, we completed an interim quantitative goodwill impairment test in conjunction with our normal quarterly reporting process. Consistent with past practice, the estimated fair value of our reporting units was determined using a combination of the present value of expected cash flows (“income approach”) and the guideline public company method (“market approach”). These fair value determinations require considerable judgment and are sensitive to changes in underlying assumptions, estimates, and market factors. We have not made any material changes to our impairment loss assessment methodology in the past three fiscal years. See “ Note 1. Description of Business and Summary of Significant Accounting Policies — Goodwill and Long-Lived Assets ” of the Notes to Consolidated Financial Statements section in the Fiscal 2022 Form 10-K for additional information regarding our goodwill policy and testing. As a result of this interim goodwill impairment analysis, we recorded a pre-tax, non-cash impairment charge of $ 1,893.0 million ($ 1,829.8 million after-tax) in the second quarter; $ 1,378.7 million in the Global Paper reportable segment and $ 514.3 million in the Corrugated Packaging reportable segment. As of March 31, 2023, after reflecting the impairment charges, the Corrugated Packaging, Consumer Packaging and Distribution reporting units had goodwill of $ 2,593.7 million, $ 1,520.7 million, and $ 138.6 million, respectively. Goodwill associated with the Global Paper reporting unit had been written off in its entirety as of March 31, 2023. Following the interim goodwill impairment analysis, our Consumer Packaging and Distribution reporting units had fair values that exceeded their carrying values by approximately 23 % and 15 %, respectively; and the fair value of our Corrugated Packaging reporting unit approximated its carrying value. Because the fair values of the Corrugated Packaging and Distribution reporting units are not substantially more than their carrying values, these reporting units have greater risk of future impairments should we experience adverse changes in our assumptions, estimates, or market factors. The discount rates used in the impairment analysis for our reporting units ranged from 9.5 % to 13.5 %. Our perpetual growth rates ranged from 0.0 % to 1.0 %. Had we concluded it was appropriate to increase the discount rate used to estimate the fair values of the Consumer Packaging and Distribution reporting units by 100 basis points, the fair values of each of these reporting units would have continued to exceed their carrying values. If the assumptions, estimates, and market factors underlying our fair value determinations change adversely, we may be exposed to additional impairment charges, particularly with respect to the Corrugated Packaging and Distribution reporting units, which could be material. Additionally, there are certain risks inherent to our operations as described in Item 1A. “Risk Factors” herein and in our Fiscal 2022 Form 10-K that could affect our estimates and assumptions in the future. Our long-lived assets, including intangible assets remain recoverable. See “ Note 5. Restructuring and Other Costs ” for additional information on long-lived asset write-offs included in restructuring charges recorded in conjunction with our decision to permanently cease operations at the North Charleston, SC containerboard mill.

Interest Expense, Net

Interest Expense, Net	6 Months Ended
	Mar. 31, 2023
Interest Income (Expense), Net [Abstract]
Interest Expense, Net	Note 9. Interest Expense, Net The components of interest expense, net are as follows (in millions): Three Months Ended Six Months Ended March 31, March 31, 2023 2022 2023 2022 Interest expense $ ( 134.3 ) $ ( 84.9 ) $ ( 253.2 ) $ ( 183.2 ) Interest income 25.9 12.4 47.5 24.0 Interest expense, net $ ( 108.4 ) $ ( 72.5 ) $ ( 205.7 ) $ ( 159.2 ) Cash paid for interest, net of amounts capitalized, of $ 213.5 million and $ 176.0 million were made during the six months ended March 31, 2023 and March 31, 2022 , respectively.

Inventories

Inventories	6 Months Ended
	Mar. 31, 2023
Inventory Disclosure [Abstract]
Inventories	Note 10. Inventories We value substantially all of our U.S. inventories at the lower of cost or market, with cost determined on a last-in first-out (“ LIFO ”) basis. We value all other inventories at the lower of cost and net realizable value, with cost determined using methods that approximate cost computed on a first-in first-out (“ FIFO ”) basis. These other inventories represent primarily foreign inventories, distribution business inventories, spare parts inventories and certain inventoried supplies. The components of inventories were as follows (in millions): March 31, September 30, Finished goods and work in process $ 1,187.4 $ 1,102.4 Raw materials 1,234.2 1,135.9 Spare parts and supplies 568.8 529.6 Inventories at FIFO cost 2,990.4 2,767.9 LIFO reserve ( 440.1 ) ( 450.8 ) Net inventories $ 2,550.3 $ 2,317.1

Property, Plant and Equipment

Property, Plant and Equipment	6 Months Ended
	Mar. 31, 2023
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Note 11. Property, Plant and Equipment The components of property, plant and equipment were as follows (in millions): March 31, September 30, Property, plant and equipment at cost: Land and buildings $ 3,101.4 $ 2,646.4 Machinery and equipment 17,970.4 16,592.5 Forestlands 100.8 95.7 Transportation equipment 23.3 24.2 Leasehold improvements 104.9 103.4 21,300.8 19,462.2 Less: accumulated depreciation, depletion and ( 10,137.8 ) ( 9,380.8 ) Property, plant and equipment, net $ 11,163.0 $ 10,081.4 Accrued additions to property, plant and equipment at March 31, 2023 and September 30, 2022 were $ 139.5 million and $ 223.2 million, respectively.

Fair Value

Fair Value	6 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value	Note 12. Fair Value Assets and Liabilities Measured or Disclosed at Fair Value We estimate fair values in accordance with ASC 820, “Fair Value Measurement ”. We have not changed the valuation techniques for measuring the fair value of any financial assets or liabilities during the fiscal year. See “ Note 12. Fair Value ” of the Notes to Consolidated Financial Statements section in the Fiscal 2022 Form 10-K for more information. We disclose the fair value of our long-term debt in “ Note 13. Debt ”. We disclose the fair value of our derivative instruments in “ Note 15. Derivatives ”. We disclose the fair value of our pension and postretirement assets and liabilities in “ Note 5. Retirement Plans ” of the Notes to Consolidated Financial Statements section in the Fiscal 2022 Form 10-K. Financial Instruments Not Recognized at Fair Value Financial instruments not recognized at fair value on a recurring or nonrecurring basis include cash and cash equivalents, accounts receivable, certain other current assets, short-term debt, accounts payable, certain other current liabilities and long-term debt. With the exception of long-term debt, the carrying amounts of these financial instruments approximate their fair values due to their short maturities. Nonrecurring Fair Value Measurements We measure certain assets and liabilities at fair value on a nonrecurring basis. These assets and liabilities include equity method investments when they become subject to fair value remeasurement upon obtaining control due to a step-up acquisition or when they are deemed to be other-than-temporarily impaired, investments for which the fair value measurement alternative is elected, assets acquired and liabilities assumed when they are deemed to be other-than-temporarily impaired, assets acquired and liabilities assumed in a merger or an acquisition or in a nonmonetary exchange, property, plant and equipment, right-of-use (“ ROU ”) assets related to operating or finance leases, and goodwill and other intangible assets that are written down to fair value when they are held for sale or determined to be impaired. In the second quarter of fiscal 2023, we recorded a $ 1.9 billion pre-tax, non-cash goodwill impairment charge. See “ Note 8. Segment Information ” for additional information. See “ Note 5. Restructuring and Other Costs ” for impairments associated with restructuring activities including the impairment of our North Charleston, SC containerboard mill in the second quarter of fiscal 2023 and our Panama City, FL mill in the second quarter of fiscal 2022 and other such similar items presented as “PP&E and related costs”. Fair value of the remaining land, building and improvements was determined based on a third-party appraisal. During the three and six months ended March 31, 2023 and 2022, we did not have any significant nonfinancial assets or liabilities, other than goodwill and restructuring, that were measured at fair value on a nonrecurring basis in periods subsequent to initial recognition. Accounts Receivable Sales Agreements We are a party to an accounts receivable sales agreement to sell to a third-party financial institution all of the short-term receivables generated from certain customer trade accounts. On September 16, 2022, we amended the then-existing $ 700.0 million facility to extend the maturity to September 15, 2023 (the “ A/R Sales Agreement ”) and addressed the transition from LIBOR to the Secure Overnight Funding Rate (" SOFR "). The terms of the A/R Sales Agreement limit the balance of receivables sold to the amount available to fund such receivables sold, thereby eliminating the receivable for proceeds from the financial institution at any transfer date. Transfers under the A/R Sales Agreement meet the requirements to be accounted for as sales in accordance with guidance in ASC 860, “Transfers and Servicing”. We also have a similar $ 110.0 million facility that was amended on December 2, 2021. The amendment included addressing the transition from LIBOR to SOFR. The facility was again amended on December 2, 2022 to extend the term through December 4, 2023 and included certain fee and other general revisions. The facility purchase limit was unchanged and the facility remains uncommitted. The customers from these facilities are not included in the Receivables Securitization Facility (as hereinafter defined) that is discussed in “ Note 13. Debt ”. The following table presents a summary of these accounts receivable sales agreements for the six months ended March 31, 2023 and March 31, 2022 (in millions): Six Months Ended March 31, 2023 2022 Receivable from financial institutions at beginning of fiscal year $ — $ — Receivables sold to the financial institutions and derecognized ( 1,426.9 ) ( 1,454.3 ) Receivables collected by financial institutions 1,432.0 1,410.9 Cash (payments to) proceeds from financial institutions ( 5.1 ) 43.4 Receivable from financial institutions at March 31 $ — $ — Receivables sold under these accounts receivable sales agreements as of the respective balance sheet dates were approximately $ 719.6 million and $ 724.7 million as of March 31, 2023 and September 30, 2022, respectively. Cash proceeds related to the receivables sold are included in Net cash provided by operating activities in the consolidated statements of cash flows in the accounts receivable line item. While the expense recorded in connection with the sale of receivables may vary based on current rates and levels of receivables sold, the expense recorded in connection with the sale of receivables was $ 13.3 million and $ 24.2 million for the three and six months ended March 31, 2023 , respectively, and $ 3.2 million and $ 5.4 million for the three and six months ended March 31, 2022, and is recorded in “Other (expense) income, net” in the consolidated statements of operations. Although the sales are made without r ecourse, we maintain continuing involvement with the sold receivables as we provide collections services related to the transferred assets. The associated servicing liability is not material given the high credit quality of the customers underlying the receivables and the anticipated short collection period.

Debt

Debt	6 Months Ended
	Mar. 31, 2023
Debt [Abstract]
Debt	Note 13. Debt The public bonds issued by WRKCo Inc. (" WRKCo "), WestRock RKT, LLC (“ RKT ”) and WestRock MWV, LLC (“ MWV ”) are guaranteed by WestRock and have cross-guarantees between the three companies. The public bonds are unsecured, unsubordinated obligations that rank equally in right of payment with all of our existing and future unsecured, unsubordinated obligations. The bonds are effectively subordinated to any of our existing and future secured debt to the extent of the value of the assets securing such debt and to the obligations of our non-debtor/guarantor subsidiaries. The industrial development bonds associated with the finance lease obligations of MWV are guaranteed by the Company and certain of its subsidiaries. At March 31, 2023, all of our debt was unsecured with the exception of our Receivables Securitization Facility (as defined below) and finance lease obligations. The following table shows the carrying value of the individual components of our debt (in millions): March 31, 2023 September 30, 2022 Public bonds due fiscal 2024 to 2028 $ 3,435.6 $ 3,433.4 Public bonds due fiscal 2029 to 2033 2,746.5 2,753.3 Public bonds due fiscal 2037 to 2047 177.5 177.8 Revolving credit and swing facilities 218.1 286.3 Term loan facilities 1,597.1 598.2 Receivables securitization 375.0 — Commercial paper 291.4 — International and other debt 125.0 127.6 Finance lease obligations 410.9 287.5 Vendor financing and commercial card 128.5 123.1 Total debt 9,505.6 7,787.2 Less: current portion of debt 501.6 212.2 Long-term debt due after one year $ 9,004.0 $ 7,575.0 A portion of the debt classified as long-term may be paid down earlier than scheduled at our discretion without penalty. Our credit facilities contain certain restrictive covenants, including a covenant to satisfy a debt to capitalization ratio. We test and report our compliance with these covenants as required by these facilities and were in compliance with them at March 31, 2023. The estimated fair value of our debt was approximately $ 9.2 billion as of March 31, 2023 and $ 7.3 billion at September 30, 2022. The fair value of our long-term debt is categorized as level 2 within the fair value hierarchy and either is primarily based on quoted prices for those or similar instruments, or approximates their carrying amount, as the variable interest rates reprice frequently at observable current market rates. See “ Note 13. Debt ” of the Notes to Consolidated Financial Statements section in the Fiscal 2022 Form 10-K for additional information on our debt, interest rates on that debt, as well as the status of the LIBOR transition in our applicable debt facilities. Revolving Credit Facilities Revolving Credit Facility On July 7, 2022, we entered into a credit agreement (the " Revolving Credit Agreement ") that included a five-year senior unsecured revolving credit facility in an aggregate amount of $ 2.3 billion, consisting of a $ 1.8 billion U.S. revolving facility and a $ 500 million multicurrency revolving facility (collectively, the “ Revolving Credit Facility ”) with Wells Fargo Bank, National Association, as administrative agent and multicurrency agent. The Revolving Credit Facility is guaranteed by WestRock Company and certain of its subsidiaries as set forth in the Revolving Credit Agreement. At March 31, 2023 and September 30, 2022, there were no amounts outstanding under the facility. European Revolving Credit Facilities On July 7, 2022, we entered into a credit agreement (the " European Revolving Credit Agreement ") with Coöperatieve Rabobank U.A., New York Branch, as administrative agent. The European Revolving Credit Agreement provides for a three-year senior unsecured revolving credit facility in an aggregate amount of € 700.0 million and includes an incremental € 100.0 million accordion feature (the “ European Revolving Credit Facility ”). The European Revolving Credit Facility is guaranteed by WestRock Company and certain of its subsidiaries as set forth in the European Revolving Credit Agreement. At March 31, 2023 and September 30, 2022, we had borrowed € 200.0 million ($ 218.1 million) and € 270.0 million ($ 265.0 million), respectively. Term Loan Facilities Farm Loan Credit Facility On July 7, 2022, we amended and restated the prior credit agreement (the “ Farm Credit Facility Agreement ”) with CoBank, ACB, as administrative agent. The Farm Credit Facility Agreement provides for a seven-year senior unsecured term loan facility in an aggregate principal amount of $ 600 million (the “ Farm Credit Facility ”). At any time, we have the ability to request an increase in th e principal amount by up to $ 400 million by written notice. The Farm Credit Facility is guaranteed by WestRock Company and certain of its subsidiaries as set forth in the Farm Credit Facility Agreement. The carrying value of this facility at March 31, 2023 and September 30, 2022 was $ 598.4 million and $ 598.2 million, respectively. Delayed Draw Term Facility On August 18, 2022, we amended the Revolving Credit Agreement (the “ Amended Credit Agreement ”) to add a three-year s enior unsecured delayed draw term loan facility with an aggregate principal amount of up to $ 1.0 billion (the “ Delayed Draw Term Facility ”) that could be drawn in a single draw through May 31, 2023. On November 28, 2022, in connection with the Grupo Gondi Acquisition, we drew upon the facility in full. The Delayed Draw Term Facility is g uaranteed by WestRock Company and certain of its subsidiaries as set forth in the Amended Credit Agreement. We have the option to extend the maturity date by one year with full lender consent. The one-year maturity extension would cost a fee of 20 basis points. T he carrying value of this facility at March 31, 2023 was $ 998.7 million. Receivables Securitization Facility On February 28, 2023, we amended our existing $ 700.0 million receivables securitization agreement (the “ Receivables Securitization Facility ”), primarily to extend the maturity to February 27, 2026 and to complete the transition from LIBOR to Term SOFR. Term SOFR loans will be subject to a credit spread adjustment equal to 0.10 % per annum. No other changes were made to the rates in the agreement. The used borrowing rate spread above base remains at 0.90 %, and the unused rate remains at 0.25 % or 0.35 %, dependent on whether the amount borrowed is above or below 50 % of the maximum borrowing limit , respectively. At March 31, 2023 and September 30, 2022, maximum available borrowings, excluding amounts outstanding under the Receivables Securitization Facility, were $ 700.0 million and $ 700.0 million, respectively. The carrying amount of accounts receivable collateralizing the maximum available borrowings at March 31, 2023 and September 30, 2022 were approximately $ 1,222.1 million and $ 1,390.5 million, respectively. We have continuing involvement with the underlying receivables as we provide credit and collections services pursuant to the Receivables Securitization Facility. At March 31, 2023 and September 30, 2022, there was $ 375.0 million and no a mount outstanding under this facility, respectively. Commercial Paper On December 7, 2018, we established an unsecured commercial paper program with WRKCo as the issuer. Under the program, we may issue senior short-term unsecured commercial paper notes in an aggregate principal amount at any time not to exceed $ 1.0 billion with up to 397 -day maturities. The program has no expiration date and can be terminated by either the agent or us with not less than 30 days’ notice. Our Revolving Credit Facility is intended to backstop the commercial paper program. Amounts available under the program may be borrowed, repaid and re-borrowed from time to time. At March 31, 2023 , we had issued $ 291.4 million in commercial paper. At September 30, 2022, there was no amount outstanding. International and Other Debt Brazil Export Credit Note On January 18, 2021, we entered into a credit agreement to provide for R$ 500.0 million of a senior unsecured term loan of WestRock Celulose, Papel E Embalagens Ltda. (a subsidiary of the Company), as borrower, and the Company, as guarantor. The outstanding amount of the principal is being repaid in equal, semiannual installments beginning on January 19, 2023 until the facility matures on January 19, 2026 . The proceeds borrowed are to be used to support the production of goods or acquisition of inputs that are essential or ancillary to export activities. Loans issued under the facility bear interest at a floating rate based on Brazil’s Certificate of Interbank Deposit rate plus a spread of 2.50 %. At March 31, 2023 and September 30, 2022, there was R$ 428.6 million ($ 83.6 million) outstanding and R$ 500.0 million ($ 92.7 million) outstanding, respectively.

Leases

Leases	6 Months Ended
	Mar. 31, 2023
Leases [Abstract]
Leases	Note 14. Leases We lease various real estate, including certain operating facilities, warehouses, office space and land. We also lease material handling equipment, vehicles and certain other equipment. Our total lease cost, net was $ 99.3 million and $ 196.6 million during the three and six months ended March 31, 2023 , respectively. Our total lease cost, net was $ 87.1 million and $ 169.8 million during the three and six months ended March 31, 2022 , respectively. We obtained $ 69.8 million and $ 63.4 million of ROU assets in exchange for lease liabilities during the six months ended March 31, 2023 and 2022, respectively. Supplemental Balance Sheet Information Related to Leases The table below presents supplemental balance sheet information related to leases (in millions): Consolidated Balance March 31, September 30, Operating leases: Operating lease right-of-use asset Other noncurrent assets $ 657.3 $ 699.6 Current operating lease liabilities Other current liabilities $ 198.6 $ 191.9 Noncurrent operating lease liabilities Other noncurrent liabilities 505.7 551.1 Total operating lease liabilities $ 704.3 $ 743.0 Finance leases: Property, plant and equipment $ 314.8 $ 177.4 Accumulated depreciation ( 49.5 ) ( 37.3 ) Property, plant and equipment, net $ 265.3 $ 140.1 Current finance lease liabilities Current portion of debt $ 22.3 $ 14.5 Noncurrent finance lease liabilities Long-term debt due after one year 388.6 273.0 Total finance lease liabilities $ 410.9 $ 287.5 Our finance lease portfolio includes certain assets that are either fully depreciated or transferred for which the lease arrangement requires a one-time principal repayment on the maturity date of the lease obligation.

Derivatives

Derivatives	6 Months Ended
	Mar. 31, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities Disclosure [Text Block]	Note 15. Derivatives We are exposed to commodity price risk, foreign currency exchange risk and interest rate risk. To manage these risks, from time to time and to varying degrees, we may enter into a variety of financial derivative transactions and certain physical commodity transactions that are determined to be derivatives. We have designated certain natural gas commodity contracts as cash flow hedges for accounting purposes. Therefore, the entire change in fair value of the financial derivative instrument is reported as a component of other comprehensive loss and reclassified into earnings in the same line item associated with the forecasted transaction, and in the same period or periods during which the forecasted transaction affects earnings. Fair value measurements for our natural gas commodity derivatives are classified under level 2 because such measurements are estimated based on observable inputs such as commodity future prices. Approximately three-fourths of our natural gas purchases for our U.S. and Canadian mill operations are tied to NYMEX. Our natural gas hedging positions are entered in layers over multiple months and up to 12 months in advance to achieve a targeted hedging volume of up to 80% of our anticipated NYMEX-based natural gas purchases. However, we may modify our strategy based on our assessment of market conditions. For financial derivative instruments that are not designated as accounting hedges, the entire change in fair value of the financial instrument is reported immediately in current period earnings. The following table sets forth the outstanding notional amounts related to our derivative instruments (in millions): Metric March 31, September 30, Designated cash flow hedges: Natural gas commodity contracts MMBtu 21.3 18.3 Undesignated derivatives: Foreign currency contracts (1) Mexican pesos — 8,000.0 (1) At September 30, 2022, the outstanding foreign currency exchange contract was related to the purchase of 8.0 billion Mexican pesos ($ 389.9 million) for refinancing Grupo Gondi's external debt upon the Grupo Gondi Acquisition on December 1, 2022 . The following table sets forth the l ocation and fair values of our derivative instruments (in millions): Consolidated Balance March 31, September 30, Designated cash flow hedges: Natural gas commodity contracts Other current liabilities (1) $ 32.3 $ 12.0 Undesignated derivatives: Foreign currency contracts Other current assets $ — $ 3.4 (1) At September 30, 2022, liability positions by counterparty were partially offset by $ 2.3 million of asset positions where we had an enforceable right of netting. The following table sets forth gains (losses) recognized in accumulated other comprehensive loss, net of tax for cash flow hedges (in millions): Three Months Ended Six Months Ended March 31, March 31, 2023 2022 2023 2022 Natural gas commodity contracts $ ( 3.4 ) $ — $ ( 15.3 ) $ — The following table sets forth amounts of gains (losses) recognized in the consolidated statements of operations for cash flow hedges reclassified from accumulated other comprehensive loss (in millions): Three Months Ended Six Months Ended March 31, March 31, Consolidated Statement 2023 2022 2023 2022 Natural gas commodity contracts Cost of goods sold $ ( 26.8 ) $ — $ ( 40.0 ) $ — The following table sets forth amounts of gains (losses) recognized in the consolidated statements of operations for derivatives not designated as hedges (in millions): Three Months Ended Six Months Ended March 31, March 31, Consolidated Statement 2023 2022 2023 2022 Foreign currency contracts Other (expense) income, net $ — $ — $ 19.7 $ —

Special Purpose Entities

Special Purpose Entities	6 Months Ended
	Mar. 31, 2023
Special Purpose Entities [Abstract]
Special Purpose Entities	Note 16. Special Purpose Entities Pursuant to the sale of certain forestlands in 2007 and 2013, special purpose entities received and WestRock assumed upon the strategic combination of Rock-Tenn Company and MeadWestvaco Corporation's respective businesses, certain installment notes, and using these installment notes as collateral, the special purpose entities received proceeds under secured financing agreements. See “ Note 15. Special Purpose Entities ” of the Notes to Consolidated Financial Statements section in the Fiscal 2022 Form 10-K for additional information. The restricted assets and non-recourse liabilities held by special purpose entities are included in the consolidated balance sheets in the following (in millions): March 31, September 30, Other current assets $ 867.9 $ — Other noncurrent assets $ 381.1 $ 1,253.0 Other current liabilities $ 782.5 $ — Other noncurrent liabilities $ 330.2 $ 1,117.8 The decrease in Other noncurrent assets and Other noncurrent liabilities subsequent to September 30, 2022 reflects one of the installment notes becoming current in December 2022.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Mar. 31, 2023
Commitments And Contingencies [Abstract]
Commitments and Contingencies	Note 17. Commitments and Contingencies Health and Safety Our business involves the use of heavy equipment, machinery and chemicals and requires the performance of activities that create safety exposures. The health and safety of our team members is our most important responsibility, and our goal is to create a 100% safe work environment for our team members. Our safety strategy focuses on People, Process, Prevention and Performance. We have established safety policies, programs, procedures and training for our manufacturing operations. We seek to reduce exposures and eliminate life changing events through engagement, execution of targeted, results-driven activities, and implementation of systems that promote continuous improvement. We also are implementing Human Organizational Performance throughout the organization to create more resilient and safer workplaces. We are subject to a broad range of foreign, federal, state and local laws and regulations relating to occupational health and safety, and our safety program includes measures required for compliance. Failure to comply with health and safety laws and regulations, or any permits and authorizations required thereunder, could subject us to fines or other sanctions, corrective action requirements and litigation or reputational damage. We have incurred, and will continue to incur, capital expenditures to meet our health and safety compliance requirements, as well as to continually improve our safety systems. We believe that future compliance with occupational health and safety laws and regulations will not have a material adverse effect on our results of operations, financial condition or cash flows. The global impact of COVID has affected our operational and financial performance to varying degrees. The extent of the effects of future public health crises, including a resurgence of COVID, or related containment measures and government responses, are highly uncertain and cannot be predicted. Certain governmental authorities in locations where we do business have established asbestos standards for the workplace. Although we do not use asbestos in manufacturing our products, asbestos containing material (“ ACM ”) is present in some of the facilities we own or lease. For those facilities where ACM is present and ACM is subject to regulation, we have established procedures for properly managing it. Environmental We are subject to numerous international, federal, state, local and other environmental laws and regulations, including those governing discharges to air, soil and water; the management, treatment and disposal of hazardous substances, solid waste and hazardous wastes; the investigation and remediation of contamination resulting from historical site operations; and requirements relating to the use of chemicals in packaging. We are also subject to the requirements of environmental permits and similar authorizations issued by various governmental authorities. Complex and lengthy processes may be required to obtain and renew approvals, permits, and licenses for new, existing or modified facilities. Additionally, the use and handling of various chemicals or hazardous materials require release prevention plans and emergency response procedures. Our compliance initiatives related to these environmental laws and regulations could result in significant costs, which could negatively impact our results of operations, financial condition and cash flows. Failure to comply with environmental laws and regulations, or any permits and authorizations required thereunder, could subject us to fines or other sanctions, corrective action requirements and litigation or reputational damage. Environmental regulations in the U.S. and Canada will require our power boilers at certain WestRock mills to meet more stringent nitrogen oxide (“ NOx ”) emission standards beginning in 2026. In the U.S., the Environmental Protection Agency recently finalized a regulation, known as the “Good Neighbor” Plan, that is intended to reduce ozone-forming emissions of nitrogen oxides from industrial facilities in 20 states during the ozone season (May through September). In Canada, the government is implementing the Multi-Sector Air Pollutants Regulation, which establishes tighter NOx limits for boilers and heaters in several industries, including pulp and paper. Our preliminary analysis indicates that to meet these new requirements, we need to reduce NOx emissions from nine power boilers at four mills in the U.S. and one in Canada. Our environmental and engineering teams are working on strategies for meeting these new limits. Based on our initial assessment, we do not believe the costs of compliance will be material. We have been named as a potentially responsible party (“ PRP ”) in environmental remediation actions under various federal and state laws, including the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (“ CERCLA ”). Many of these proceedings involve the cleanup of hazardous substances at sites that received waste from many different parties. While joint and several liability is authorized under CERCLA and analogous state laws, liability for CERCLA cleanups is typically shared with other PRPs, and costs are commonly allocated according to relative amounts of waste deposited and other factors. We believe we have insurance and contractual indemnification rights that may allow us to recover certain defense and other costs at some CERCLA sites. Other remediation costs typically associated with the cleanup of hazardous substances at our current, closed or formerly-owned facilities, are recorded as liabilities in our consolidated balance sheets. Remediation costs are recorded in our financial statements when they become probable and reasonably estimable. See “ Note 17. Commitments and Contingencies ” of the Notes to Consolidated Financial Statements section in the Fiscal 2022 Form 10-K for information related to environmental matters. As of March 31, 2023 , we had $ 7.7 million reserved for environmental liabilities on an undiscounted basis, of which $ 1.4 million is included in Other noncurrent liabilities and $ 6.3 million is included in Other current liabilities, on the consolidated balance sheets, including amounts accrued in connection with environmental obligations relating to manufacturing facilities that we have closed. We believe the liability for these matters was adequately reserved at March 31, 2023. Climate Change Climate change presents risks and uncertainties for us, as well as certain potential opportunities. With respect to physical risks, our physical assets and infrastructure, including our manufacturing operations, have been, and may be in future periods impacted by severe weather-related events such as hurricanes and floods, potentially resulting in items such as physical damage to our facilities and lost production. Unpredictable weather patterns also may result in supply chain disruptions and increased material costs, such as through impacts to virgin fiber supplies and prices, which may fluctuate during prolonged periods of heavy rain or drought or during tree disease or insect epidemics that may be related to variations in climate conditions. On the other hand, changes in climate also could result in more accommodating weather patterns for greater periods of time in certain areas, which may create favorable fiber market conditions. We incorporate a review of meteorological forecast data into our fiber procurement decisions and strategies. To the extent that severe weather-related risks materialize, and we are unprepared for them, we may incur unexpected costs, which could have a material effect on our results of operations, cash flows and financial condition, and the trading price of our Common Stock may be adversely impacted. See “ Note 17. Commitments and Contingencies ” of the Notes to Consolidated Financial Statements section in the Fiscal 2022 Form 10-K for information related to climate change. Brazil Tax Liability We are challenging claims by the Brazil Federal Revenue Department that we underpaid tax, penalties and interest associated with a claim that a subsidiary of MeadWestvaco Corporation (the predecessor of WestRock MWV, LLC) had reduced its tax liability related to the goodwill generated by the 2002 merger of two of its Brazil subsidiaries. The matter has proceeded through the Brazil Administrative Council of Tax Appeals (“ CARF ”) principally in two proceedings, covering tax years 2003 to 2008 and 2009 to 2012. The tax and interest claim relating to tax years 2009 to 2012 was finalized and is now the subject of an annulment action we filed in the Brazil federal court. CARF notified us of its final decision regarding the tax, penalties and interest claims relating to tax years 2003 to 2008 on June 3, 2020. We have filed an annulment action in Brazil federal court with respect to that decision as well. The dispute related to fraud penalties for tax years 2009 to 2012 was resolved by CARF in favor of WestRock effective January 23, 2023. We assert that we have no liability in these matters. The total amount in dispute before CARF and in the annulment actions relating to the claimed tax deficiency wa s R$ 695 million ($ 136 million) as of March 31, 2023, including various penalties and interest. The U.S. dollar equivalent has fluctuated significantly due to changes in exchange rates. The amount of our uncertain tax position reserve for this matter, which excludes certain penalties, is included in the unrecognized tax benefits table in our Fiscal 2022 Form 10-K, see “ Note 6. Income Taxes ” of the Notes to Consolidated Financial Statements. Resolution of the uncertain tax positions could have a material adverse effect on our cash flows and results of operations or materially benefit our results of operations in future periods depending upon their ultimate resolution. Other Litigation During fiscal 2018, we submitted formal notification to withdraw from the PIUMPF and recorded a liability associated with the withdrawal. Subsequently, in fiscal 2019 and 2020, we received demand letters from PIUMPF, including a demand for withdrawal liabilities and for our proportionate share of PIUMPF's accumulated funding deficiency, and we refined our liability, the impact of which was not significant. We began making monthly payments for the PIUMPF withdrawal liabilities in fiscal 2020, excluding the accumulated funding deficiency demands, which we dispute. In February 2020, we received a demand letter from PIUMPF asserting that we owe $ 51.2 million for our pro-rata share of PIUMPF’s accumulated funding deficiency, including interest. Similarly, in April 2020, we received an updated demand letter related to a subsidiary of ours asserting that we owe $ 1.3 million of additional accumulated funding deficiency, including interest. In July 2021, the PIUMPF filed suit against us in the U.S. District Court for the Northern District of Georgia claiming the right to recover our pro-rata share of the pension fund’s accumulated funding deficiency, along with interest, liquidated damages and attorney's fees. We believe we are adequately reserved for this matter. See “ Note 5. Retirement Plans — Multiemployer Plans ” of the Notes to Consolidated Financial Statements section in the Fiscal 2022 Form 10-K for more information regarding our withdrawal liabilities. We have been named a defendant in asbestos-related personal injury litigation. To date, the costs resulting from the litigation, including settlement costs, have not been significant. As of March 31, 2023 , there were approximately 700 such lawsuits. We believe that we have substantial insurance coverage, subject to applicable deductibles and policy limits, with respect to asbestos claims. We also have valid defenses to these asbestos-related personal injury claims and intend to continue to defend them vigorously. Should the volume of litigation grow substantially, it is possible that we could incur significant costs resolving these cases. We do not expect the resolution of pending asbestos litigation and proceedings to have a material adverse effect on our results of operations, financial condition or cash flows. In any given period or periods, however, it is possible such proceedings or matters could have an adverse effect on our results of operations, financial condition or cash flows. At March 31, 2023 , we had $ 12.2 million reserved for these matters. We are a defendant in a number of other lawsuits and claims arising out of the conduct of our business. While the ultimate results of such suits or other proceedings against us cannot be predicted, we believe the resolution of these other matters will not have a material adverse effect on our results of operations, financial condition or cash flows. Indirect Tax Claim In March 2017, the Supreme Court of Brazil issued a decision concluding that certain state value added tax should not be included in the calculation of federal gross receipts taxes. Subsequently, in fiscal 2019 and 2020, the Supreme Court of Brazil rendered favorable decisions on eight of our cases granting us the right to recover certain state value added tax. In response, the tax authorities in Brazil filed a Motion of Clarification with the Supreme Court of Brazil. Based on our evaluation and the opinion of our tax and legal advisors, we believe the decision reduced our gross receipts tax in Brazil prospectively and retrospectively, and allowed us to recover tax amounts collected by the government. We recorded estimated recoveries across several periods beginning in the fourth quarter of fiscal 2019 as we reviewed the documents and the amount became estimable. In May 2021, the Supreme Court of Brazil judged the Motion of Clarification and concluded on the gross methodology, which was consistent with our evaluation and that of our tax and legal advisors. We are monitoring the statuses of our remaining cases, and subject to the resolution in the courts, we may record additional amounts in future periods. See “ Note 17. Commitments and Contingencies — Indirect Tax Claim ” of the Notes to Consolidated Financial Statements section in the Fiscal 2022 Form 10-K for information related to our previously recorded estimated recoveries. Guarantees We make certain guarantees in the normal course of conducting our operations, for compliance with certain laws and regulations, or in connection with certain business dispositions. The guarantees include items such as funding of net losses in proportion to our ownership share of certain joint ventures, debt guarantees related to certain unconsolidated entities acquired in acquisitions, indemnifications of lessors in certain facilities and equipment operating leases for items such as additional taxes being assessed due to a change in tax law and certain other agreements. We estimate our exposure to these matters to be less than $ 50 million. As of March 31, 2023 , we had recorded $ 0.8 million for the estimated fair value of these guarantees. We are unable to estimate our maximum exposure under operating leases because it is dependent on potential changes in tax laws; however, we believe our exposure related to guarantees would not have a material impact on our results of operations, financial condition or cash flows.

Equity and Other Comprehensive

Equity and Other Comprehensive Income (Loss)	6 Months Ended
	Mar. 31, 2023
Equity [Abstract]
Equity and Other Comprehensive Income (Loss)	Note 18. Equity and Other Comprehensive Income (Loss) Equity Stock Repurchase Program In July 2015, our board of directors authorized a repurchase program of up to 40.0 million shares of our outstanding common stock, par value $ 0.01 per share (“ Common Stock ”), representing approximately 15 % of our outstanding Common Stock as of July 1, 2015. On May 4, 2022, our board of directors authorized a new repurchase program of up to 25.0 million shares of our Common Stock, representing approximately 10 % of our outstanding Common Stock, plus any unutilized shares left from the July 2015 authorization. Shares of our Common Stock may be purchased from time to time in open market or privately negotiated transactions. The timing, manner, price and amount of repurchases will be determined by management at its discretion based on factors including the market price of our Common Stock, general economic and market conditions and applicable legal requirements. The repurchase program may be commenced, suspended or discontinued at any time. Pursuant to the programs, in the six months ended March 31, 2023, we had no share repurchases. In the six months ended March 31, 2022, we repurchased approximately 7.2 million shares of our Common Stock for an aggregate cost of $ 332.1 million. The amount reflected as purchased in the consolidated statements of cash flows varies due to the timing of share settlement. As of March 31, 2023, we had approximate ly 29.0 million shares of Common Stock available for repurchase under the program. Accumulated Other Comprehensive Loss The tables below summarize the changes in accumulated other comprehensive loss, net of tax, by component for the six months ended March 31, 2023 and March 31, 2022 (in millions): Deferred (Loss) Income on Cash Defined Benefit Foreign Total (1) Balance at September 30, 2022 $ ( 9.1 ) $ ( 741.6 ) $ ( 703.6 ) $ ( 1,454.3 ) Other comprehensive (loss) income before ( 45.3 ) — 299.7 254.4 Amounts reclassified from accumulated other 30.0 22.4 29.0 81.4 Net current period other comprehensive (loss) income ( 15.3 ) 22.4 328.7 335.8 Balance at March 31, 2023 $ ( 24.4 ) $ ( 719.2 ) $ ( 374.9 ) $ ( 1,118.5 ) (1) All amounts are net of tax and noncontrolling interests. Deferred (Loss) Income on Cash Defined Benefit Foreign Total (1) Balance at September 30, 2021 $ ( 0.2 ) $ ( 536.5 ) $ ( 462.4 ) $ ( 999.1 ) Other comprehensive income before — 0.1 113.4 113.5 Amounts reclassified from accumulated other — 5.4 — 5.4 Net current period other comprehensive income — 5.5 113.4 118.9 Balance at March 31, 2022 $ ( 0.2 ) $ ( 531.0 ) $ ( 349.0 ) $ ( 880.2 ) (1) All amounts are net of tax and noncontrolling interests. The net of tax amounts were determined using the jurisdictional statutory rates, and reflect effective tax rates averaging 26 % to 27 % for the six months ended March 31, 2023 and 25 % to 26 % for the six months ended March 31, 2022. Although we are impacted by the exchange rates of a number of currencies to varying degrees by period, our foreign currency translation adjustments recorded in accumulated other comprehensive loss for the six months ended March 31, 2023 were primarily due to gains in the Mexican Peso, British Pound, Brazilian Real and Czech Koruna, each against the U.S. dollar. Foreign currency translation adjustments recorded in accumulated other comprehensive loss for the six months ended March 31, 2022 were primarily due to gains in the Brazilian Real, Canadian dollar and Mexican Peso, partially offset by losses in the British Pound, each against the U.S. dollar. The following table summarizes the reclassifications out of accumulated other comprehensive loss by component (in millions): Three Months Ended Three Months Ended March 31, 2023 March 31, 2022 Pre-tax Tax Net of Tax Pre-tax Tax Net of Tax Amortization of defined benefit pension and (1) Actuarial losses (2) $ ( 13.2 ) $ 3.3 $ ( 9.9 ) $ ( 1.9 ) $ 0.5 $ ( 1.4 ) Prior service costs (2) ( 1.9 ) 0.5 ( 1.4 ) ( 1.9 ) 0.5 ( 1.4 ) Subtotal defined benefit plans ( 15.1 ) 3.8 ( 11.3 ) ( 3.8 ) 1.0 ( 2.8 ) Derivative Instruments: (1) Natural gas commodity hedge loss (3) ( 26.8 ) 6.7 ( 20.1 ) — — — Total reclassifications for the period $ ( 41.9 ) $ 10.5 $ ( 31.4 ) $ ( 3.8 ) $ 1.0 $ ( 2.8 ) (1) Amounts in parentheses indicate charges to earnings. Amounts pertaining to noncontrolling interests are excluded. (2) Included in the computation of net periodic pension cost. See “ Note 6. Retirement Plans ” for additional details. (3) These accumulated other comprehensive loss components are included in Cost of goods sold. Six Months Ended Six Months Ended March 31, 2023 March 31, 2022 Pre-tax Tax Net of Tax Pre-tax Tax Net of Tax Amortization of defined benefit pension and (1) Actuarial losses (2) $ ( 26.5 ) $ 6.9 $ ( 19.6 ) $ ( 3.5 ) $ 0.9 $ ( 2.6 ) Prior service costs (2) ( 3.8 ) 1.0 ( 2.8 ) ( 3.8 ) 1.0 ( 2.8 ) Subtotal defined benefit plans ( 30.3 ) 7.9 ( 22.4 ) ( 7.3 ) 1.9 ( 5.4 ) Foreign currency translation adjustments: (1) Recognition of previously unrealized (3) ( 29.0 ) — ( 29.0 ) — — — Derivative Instruments: (1) Natural gas commodity hedge loss (4) ( 40.0 ) 10.0 ( 30.0 ) — — — Total reclassifications for the period $ ( 99.3 ) $ 17.9 $ ( 81.4 ) $ ( 7.3 ) $ 1.9 $ ( 5.4 ) (1) Amounts in parentheses indicate charges to earnings. Amounts pertaining to noncontrolling interests are excluded. (2) Included in the computation of net periodic pension cost. See “ Note 6. Retirement Plans ” for additional details. (3) Amount reflected in Equity in income (loss) of unconsolidated entities in the consolidated statements of operations. (4) These accumulated other comprehensive loss components are included in Cost of goods sold.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Mar. 31, 2023
Earnings Per Share [Abstract]
Earnings Per Share	Note 19. Earnings Per Share The restricted stock grants to non-employee directors prior to fiscal 2022 were considered participating securities as they received non-forfeitable rights to dividends at the same rate as our Common Stock. As participating securities, we included these instruments in the earnings allocation in computing earnings per share under the two-class method described in ASC 260, “ Earnings per Share ”. Beginning in fiscal 2022, non-employee directors began receiving equity grants in the form of restricted stock units, which are not considered participating securities as the rights to dividends accrued during the vesting period are forfeitable. The following table sets forth the computation of basic and diluted earnings per share under the two-class method (in millions, except per share data): Three Months Ended Six Months Ended March 31, March 31, 2023 2022 2023 2022 Numerator: Net (loss) income attributable to common $ ( 2,006.1 ) $ 39.9 $ ( 1,960.8 ) $ 222.2 Less: Distributed and undistributed income — ( 0.1 ) — ( 0.1 ) Distributed and undistributed (loss) income $ ( 2,006.1 ) $ 39.8 $ ( 1,960.8 ) $ 222.1 Denominator: Basic weighted average shares outstanding 255.6 263.4 255.2 264.0 Effect of dilutive stock options and non- — 1.9 — 2.1 Diluted weighted average shares outstanding 255.6 265.3 255.2 266.1 Basic (loss) earnings per share attributable to $ ( 7.85 ) $ 0.15 $ ( 7.68 ) $ 0.84 Diluted (loss) earnings per share attributable to $ ( 7.85 ) $ 0.15 $ ( 7.68 ) $ 0.83 Approximately 2.5 million and 0.4 million shares underlying awards in the three months ended March 31, 2023 and 2022, respectively, were not included in computing diluted earnings per share because the effect would have been antidilutive. Approximately 2.8 million and 0.4 million shares underlying awards in the six months ended March 31, 2023 and 2022, respectively, were not included in computing diluted earnings per share because the effect would have been antidilutive.

Basis of Presentation and Sig_2

Basis of Presentation and Significant Accounting Policies (Policies)	6 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation Our independent registered public accounting firm has not audited the accompanying interim financial statements. We derived the consolidated balance sheet at September 30, 2022 from the audited consolidated financial statements included in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022 (the “ Fiscal 2022 Form 10-K ”). In the opinion of management, all normal recurring adjustments necessary for the fair presentation of the consolidated financial statements have been included for the interim periods reported. The interim financial statements have been prepared in accordance with accounting principles generally accepted in the U.S. (“ GAAP ”) for interim financial information and with Article 10 of Regulation S-X of the Securities and Exchange Commission (“ SEC ”). Accordingly, they omit certain notes and other information from the interim financial statements presented in this report. Therefore, these interim financial statements should be read in conjunction with the Fiscal 2022 Form 10-K. The results for the three and six months ended March 31, 2023 are not necessarily indicative of results that may be expected for the full year. On December 1, 2022 , we completed our previously announced acquisition of the remaining 67.7 % interest in Gondi, S.A. de C.V. (“ Grupo Gondi ”) for $ 969.8 million in cash and the assumption of debt (“ Grupo Gondi Acquisition ”). We have accounted for this acquisition as a business combination resulting in the consolidation of Grupo Gondi. See “ Note 3. Acquisitions ” for additional information. On December 1, 2022, we sold our Eaton, IN, and Aurora, IL uncoated recycled paperboard mills for $ 50 million, subject to a working capital adjustment. We received proceeds of $ 25 million, a preliminary working capital settlement of $ 0.9 million and are financing the remaining $ 25 million. Pursuant to the terms of the sale agreement, we transferred the control of these mills to the buyer and recorded a pre-tax gain on sale of $ 11.1 million recorded in Other (expense) income, net in our consolidated statements of operations. In November 2022, we announced our entry into a definitive agreement to divest our interior partitions converting operations (our ownership interest in RTS Packaging, LLC) and to sell our Chattanooga, TN uncoated recycled paperboard mill to our joint venture partner for $ 330 million, subject to a working capital adjustment. The transaction is expected to close in fiscal 2023 , subject to the satisfaction of closing conditions, including the receipt of regulatory approval. Accordingly, the related assets and liabilities have been reported in the consolidated balance sheet as of March 31, 2023 as assets and liabilities held for sale. See “ Note 4. Held for Sale ” for additional information.
Reclassifications and Adjustments	Reclassifications and Adjustments Certain amounts in prior periods have been reclassified to conform with the current year presentation.
COVID-19 Pandemic	COVID-19 Pandemic The global impact of the COVID-19 pandemic (" COVID ") has affected our operational and financial performance to varying degrees. The extent of the effects of future public health crises, including a resurgence of COVID, or related containment measures and government responses are highly uncertain and cannot be predicted.
Ransomware Incident	Ransomware Incident As previously disclosed, on January 23, 2021 we detected a ransomware incident impacting certain of our systems. Promptly upon our detection of this incident, we initiated response and containment protocols and our security teams, supplemented by leading cyber defense firms, worked to remediate this incident. These actions included taking preventative measures, such as shutting down certain systems out of an abundance of caution, as well as taking steps to supplement existing security monitoring, scanning and protective measures. In our Form 10-Q for the second quarter of fiscal 2021, we announced that all systems were back in service. In the first and second quarters of fiscal 2022, we received additional business interruption recoveries of $ 5 million and $ 5 million, respectively, related to the ransomware incident, which we recorded as a reduction of Cost of goods sold and presented in net cash provided by operating activities on our consolidated statements of cash flows. See “ Note 1. Description of Business and Summary of Significant Accounting Policies — Ransomware Incident ” of the Notes to Consolidated Financial Statements section in the Fiscal 2022 Form 10-K for additional information, including recoveries ($ 15 million in fiscal 2021 and $ 57.2 million in fiscal 2022) and resiliency efforts and objectives.
Significant Accounting Policies	Significant Accounting Policies See “ Note 1. Description of Business and Summary of Significant Accounting Policies ” of the Notes to Consolidated Financial Statements section in the Fiscal 2022 Form 10-K for a summary of our significant accounting policies.
New Accounting Standards - Recently Adopted	New Accounting Standards — Recently Adopted In November 2021, the Financial Accounting Standards Board (“ FASB ”) issued Accounting Standards Update (“ ASU ”) 2021-10, “ Government Assistance (Topic 832) – Disclosures by Business Entities about Government Assistance ”. This ASU aims to increase the transparency of government assistance through the annual disclosure of the types of assistance, an entity’s accounting for the assistance and the effect of the assistance on an entity’s financial statements. This ASU is effective for annual periods beginning after December 15, 2021 (fiscal 2023 for us), with early adoption permitted. We adopted the provisions of ASU 2021-10 beginning October 1, 2022 . The adoption of this ASU did no t have a material impact on our consolidated financial statements. In October 2021, the FASB issued ASU 2021-08, “ Business Combinations (Topic 805) – Accounting for Contract Assets and Contract Liabilities from Contracts with Customers” . This ASU requires an entity to recognize and measure contract assets and contract liabilities acquired in a business combination in accordance with ASC 606 “ Revenue from Contracts with Customers ” (“ ASC 606 ”). This ASU aims to reduce diversity in practice and increase comparability for both the recognition and measurement of acquired revenue contracts with customers at the date of and after a business combination. This ASU is effective for fiscal years beginning after December 15, 2022 (fiscal 2024 for us), including interim periods therein, with early adoption permitted. We early adopted the provisions of ASU 2021-08 beginning October 1, 2022 . The adoption of this ASU did not have a material impact on our consolidated financial statements. In March 2020, the FASB issued ASU 2020-04, “ Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting ”. This ASU provides temporary optional expedients and exceptions for applying GAAP guidance on contract modifications and hedge accounting to ease the financial reporting burdens of the expected market transition from LIBOR and other interbank offered rates to alternative reference rates, such as the Secured Overnight Financing Rate. In January 2021, the FASB issued ASU 2021-01, which adds implementation guidance to clarify certain optional expedients in Topic 848. The ASUs could be adopted after their respective issuance dates through December 31, 2022. In December 2022, the FASB issued ASU 2022-06, “ Reference Rate Reform (Topic 848): Deferral of the Sunset Date of Topic 848 ”, which extends the period of time entities can utilize the reference rate reform relief guidance under ASU 2020-04 from December 31, 2022 to December 31, 2024. We are in the process of reviewing and updating our contracts to a new reference rate. We have been addressing the LIBOR transition in our applicable debt facilities and have completed the transition on all of our significant facilities. See “ Note 13. Debt ” of the Notes to Consolidated Financial Statements section in the Fiscal 2022 Form 10-K for additional information on our recent credit facility changes. We adopted the provisions of this optional guidance beginning October 1, 2022 . The adoption of these ASUs did no t have a material impact on our consolidated financial statements.
New Accounting Standards - Recently Issued	New Accounting Standards — Recently Issued In March 2023, the FASB issued ASU 2023-01, “ Leases (Topic 842): Common Control Arrangements ”. This ASU requires all lessees to amortize leasehold improvements associated with common control leases over their useful life to the common control group and account for them as a transfer of assets between entities under common control at the end of the lease. This update is effective for fiscal years beginning after December 15, 2023 (fiscal 2025 for us), including interim periods therein, with early adoption permitted in any annual or interim period as of the beginning of the related fiscal year. We are evaluating the impact of this ASU. In September 2022, the FASB issued ASU 2022-04, “ Liabilities-Supplier Finance Programs (Subtopic 405-50): Disclosure of Supplier Finance Program Obligations ”. This ASU requires that all entities that use supplier finance programs in connection with the purchase of goods and services disclose sufficient information about the program to allow a user of financial statements to understand the program’s nature, activity during the period, changes from period to period, and potential magnitude. This ASU is effective for fiscal years beginning after December 15, 2022 (fiscal 2024 for us), except for the amendment on roll forward information, which is effective for fiscal years beginning after December 15, 2023 (fiscal 2025 for us), each with early adoption permitted. We are evaluating the impact of this ASU. In June 2022, the FASB issued ASU 2022-03, “ Fair Value Measurement (Topic 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions ”. This ASU clarifies that contractual sale restrictions should not be considered in measuring the fair value of equity securities. This ASU is effective for fiscal years beginning after December 15, 2023 (fiscal 2025 for us), including interim periods therein, with early adoption permitted. We are evaluating the impact of this ASU. In March 2022, the FASB issued ASU 2022-01, “ Derivatives and Hedging (Topic 815): Fair Value Hedging – Portfolio Layer Method ”. This ASU expands and clarifies the portfolio layer method for fair value hedges of interest rate risk. This ASU is effective for fiscal years beginning after December 15, 2022 (fiscal 2024 for us), including interim periods therein, with early adoption permitted. We are evaluating the impact of this ASU.

Revenue Recognition (Tables)

Revenue Recognition (Tables)	6 Months Ended
	Mar. 31, 2023
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregates Revenue by Primary Geographical Markets	The following tables summarize our disaggregated revenue by primary geographical markets (in millions): Three Months Ended March 31, 2023 Corrugated Packaging Consumer Packaging Global Paper Distribution Intersegment Total U.S. $ 2,001.6 $ 741.7 $ 1,056.3 $ 260.3 $ ( 84.6 ) $ 3,975.3 Canada 138.0 134.5 54.4 2.8 ( 1.8 ) 327.9 Latin America 485.0 12.5 35.1 44.2 ( 3.8 ) 573.0 EMEA (1) 2.8 304.5 11.4 — ( 0.2 ) 318.5 Asia Pacific — 71.9 11.0 — — 82.9 Total $ 2,627.4 $ 1,265.1 $ 1,168.2 $ 307.3 $ ( 90.4 ) $ 5,277.6 (1) Europe, Middle East and Africa ("EMEA") Six Months Ended March 31, 2023 Corrugated Packaging Consumer Packaging Global Paper Distribution Intersegment Sales Total U.S. $ 3,975.1 $ 1,444.7 $ 2,079.0 $ 537.0 $ ( 156.1 ) $ 7,879.7 Canada 275.1 258.2 99.9 6.2 ( 3.3 ) 636.1 Latin America 710.5 64.2 68.7 85.6 ( 5.1 ) 923.9 EMEA 4.1 564.4 22.5 — ( 0.3 ) 590.7 Asia Pacific — 148.6 21.7 — — 170.3 Total $ 4,964.8 $ 2,480.1 $ 2,291.8 $ 628.8 $ ( 164.8 ) $ 10,200.7 Three Months Ended March 31, 2022 Corrugated Packaging Consumer Packaging Global Paper Distribution Intersegment Total U.S. $ 2,068.1 $ 720.0 $ 1,376.3 $ 319.1 $ ( 85.8 ) $ 4,397.7 Canada 145.9 128.4 62.2 3.8 ( 2.0 ) 338.3 Latin America 104.7 48.3 65.0 39.4 ( 0.1 ) 257.3 EMEA 0.3 277.0 17.6 — — 294.9 Asia Pacific — 76.9 17.0 — — 93.9 Total $ 2,319.0 $ 1,250.6 $ 1,538.1 $ 362.3 $ ( 87.9 ) $ 5,382.1 Six Months Ended March 31, 2022 Corrugated Packaging Consumer Packaging Global Paper Distribution Intersegment Sales Total U.S. $ 4,037.1 $ 1,368.3 $ 2,589.4 $ 603.7 $ ( 168.2 ) $ 8,430.3 Canada 286.3 242.7 120.1 7.3 ( 3.3 ) 653.1 Latin America 212.3 93.8 113.3 76.1 ( 0.2 ) 495.3 EMEA 3.3 529.1 33.5 — ( 0.1 ) 565.8 Asia Pacific — 155.4 34.4 — — 189.8 Total $ 4,539.0 $ 2,389.3 $ 2,890.7 $ 687.1 $ ( 171.8 ) $ 10,334.3
Summary of Opening and Closing Balances of Contract Assets and Contract Liabilities	The opening and closing balances of our contract assets and contract liabilities are as follows. Contract assets and contract liabilities are reported within Other current assets and Other current liabilities, respectively, on the consolidated balance sheets (in millions). Contract Assets Contract Liabilities Beginning balance - October 1, 2022 $ 244.0 $ 13.9 Increase (decrease) 13.9 ( 1.6 ) Ending balance - March 31, 2023 $ 257.9 $ 12.3

Acquisitions (Tables)

Acquisitions (Tables)	6 Months Ended
	Mar. 31, 2023
Business Combinations [Abstract]
Schedule Of Purchase Consideration Transferred	See below for a summary of the purchase consideration transferred as defined under ASC 805 (in millions): Purchase Cash consideration transferred for 67.7 % interest $ 969.8 Fair value of the previously held interest 403.7 Settlement of preexisting relationships (net receivable 40.2 Purchase consideration transferred $ 1,413.7
Summary of Fair Values of Assets Acquired and Liabilities Assumed by Major Class of Assets and Liabilities and Measurement Period Adjustments	The following table summarizes the preliminary fair values of the assets acquired and liabilities assumed in the Grupo Gondi Acquisition by major class of assets and liabilities as of the acquisition date, as well as adjustments made during fiscal 2023 (referred to as “measurement period adjustments”) (in millions): Amounts Recognized as of the Acquisition Date Measurement Period Adjustments (1) Amounts Recognized as of Acquisition Date (as Adjusted) (2) Cash and cash equivalents $ 116.3 $ — $ 116.3 Current assets, excluding cash and cash equivalents 697.0 ( 1.6 ) 695.4 Property, plant and equipment 1,380.3 15.2 1,395.5 Goodwill 231.2 2.1 233.3 Other noncurrent assets 101.4 ( 0.1 ) 101.3 Total assets acquired 2,526.2 15.6 2,541.8 Current portion of debt (3) 13.2 0.5 13.7 Current liabilities, excluding debt 384.8 0.4 385.2 Long-term debt due after one year (3) 591.4 14.7 606.1 Pension liabilities, net of current portion 35.2 — 35.2 Deferred income taxes 69.8 — 69.8 Other noncurrent liabilities 18.1 — 18.1 Total liabilities assumed 1,112.5 15.6 1,128.1 Net assets acquired $ 1,413.7 $ — $ 1,413.7 (1) The measurement period adjustments recorded in fiscal 2023 did not have a significant impact on our consolidated statements of operations for the three and six months ended March 31, 2023. (2) The measurement period adjustments were primarily due to refinements to the carrying amounts of certain assets and liabilities. The net impact of the measurement period adjustments resulted in a net increase in goodwill. Includes $ 494.8 million of Grupo Gondi debt that we assumed and repa id in connection with th e closing of the Grupo Gondi Acquisition. The remaining balance relates to current and long-term portions of finance leases.

Restructuring and Other Costs (

Restructuring and Other Costs (Tables)	6 Months Ended
	Mar. 31, 2023
Restructuring And Other Costs [Abstract]
Schedule of Restructuring and Other Costs	The following table summarizes our Restructuring and other costs (in millions): Three Months Ended Six Months Ended March 31, March 31, 2023 2022 2023 2022 Restructuring $ 441.2 $ 362.9 $ 457.5 $ 365.0 Other 3.5 0.5 20.2 0.7 Restructuring and other costs $ 444.7 $ 363.4 $ 477.7 $ 365.7
Schedule of Restructuring Charges Related to Active Restructuring Initiatives	The following table presents a summary of restructuring charges related to active restructuring initiatives that we incurred during the three and six months ended March 31, 2023 and 2022, the cumulative recorded amount since we started the initiatives and our estimate of the total we expect to incur, which is subject to a number of assumptions and actual results may differ (in millions): Three Months Ended Six Months Ended March 31, March 31, 2023 2022 2023 2022 Cumulative Total Corrugated Packaging PP&E and related costs $ 4.3 $ — $ 4.3 $ — $ 8.0 $ 8.0 Severance and other employee costs 3.6 4.4 5.3 4.0 15.0 15.0 Other restructuring costs 0.1 0.1 0.2 0.4 6.3 12.2 Restructuring total $ 8.0 $ 4.5 $ 9.8 $ 4.4 $ 29.3 $ 35.2 Consumer Packaging PP&E and related costs $ — $ — $ — $ — $ 2.2 $ 2.2 Severance and other employee costs 2.2 1.3 8.6 3.1 33.5 33.5 Other restructuring costs ( 0.2 ) 0.1 ( 0.5 ) 0.1 9.8 9.8 Restructuring total $ 2.0 $ 1.4 $ 8.1 $ 3.2 $ 45.5 $ 45.5 Global Paper PP&E and related costs $ 344.0 $ 344.4 $ 342.9 $ 344.4 $ 715.3 $ 715.3 Severance and other employee costs 19.3 10.7 19.1 10.7 30.5 39.8 Other restructuring costs 63.0 — 69.0 — 85.2 232.1 Restructuring total $ 426.3 $ 355.1 $ 431.0 $ 355.1 $ 831.0 $ 987.2 Distribution Severance and other employee costs $ 1.0 $ — $ 1.0 $ — $ 1.1 $ 1.1 Other restructuring costs 0.1 — 0.1 — 1.1 1.1 Restructuring total $ 1.1 $ — $ 1.1 $ — $ 2.2 $ 2.2 Corporate PP&E and related costs $ 0.2 $ 0.3 $ 0.6 $ 1.2 $ 11.4 $ 11.4 Severance and other employee costs 1.7 — 3.9 — 7.8 7.8 Other restructuring costs 1.9 1.6 3.0 1.1 7.5 7.5 Restructuring total $ 3.8 $ 1.9 $ 7.5 $ 2.3 $ 26.7 $ 26.7 Total PP&E and related costs $ 348.5 $ 344.7 $ 347.8 $ 345.6 $ 736.9 $ 736.9 Severance and other employee costs 27.8 16.4 37.9 17.8 87.9 97.2 Other restructuring costs 64.9 1.8 71.8 1.6 109.9 262.7 Restructuring total $ 441.2 $ 362.9 $ 457.5 $ 365.0 $ 934.7 $ 1,096.8
Schedule of Acquisition, Integration and Divestiture Costs	The following table presents our acquisition, integration and divestiture costs (in millions): Three Months Ended Six Months Ended March 31, March 31, 2023 2022 2023 2022 Acquisition costs $ 1.2 $ 0.2 $ 12.2 $ 0.4 Integration costs 1.8 0.2 6.1 0.2 Divestiture costs 0.5 0.1 1.9 0.1 Other total $ 3.5 $ 0.5 $ 20.2 $ 0.7 Acquisition costs in the table above include transaction costs related to the acquisition of the remaining interest in Grupo Gondi, as well as other matters. Accruals
Schedule of Changes in Restructuring Accrual and Reconciliation of Accrual Charges	The following table summarizes the changes in the restructuring accrual, which is primarily composed of accrued severance and other employee costs, and a reconciliation of the restructuring accrual charges to the line item “ Restructuring and other costs ” on our consolidated statements of operations (in millions): Six Months Ended March 31, 2023 2022 Accrual at beginning of fiscal year $ 25.2 $ 13.4 Additional accruals 40.2 17.6 Payments ( 18.9 ) ( 4.0 ) Adjustment to accruals ( 2.5 ) ( 0.3 ) Accrual at March 31 $ 44.0 $ 26.7 Reconciliation of accruals and charges to restructuring and other costs (in millions): Six Months Ended March 31, 2023 2022 Additional accruals and adjustments to accruals $ 37.7 $ 17.3 PP&E and related costs 347.8 345.6 Severance and other employee costs 0.2 0.5 Acquisition costs 12.2 0.4 Integration costs 6.1 0.2 Divestiture costs 1.9 0.1 Other restructuring costs 71.8 1.6 Total restructuring and other costs $ 477.7 $ 365.7

Retirement Plans (Tables)

Retirement Plans (Tables)	6 Months Ended
	Mar. 31, 2023
Retirement Plans [Abstract]
Summary of Components of Net Pension Income and Summary of Components of Postretirement Benefit Cost	Pension and Postretirement Cost (Income) The following table presents a summary of the components of net pension cost (income) (in millions): Three Months Ended Six Months Ended March 31, March 31, 2023 2022 2023 2022 Service cost $ 7.9 $ 12.7 $ 15.4 $ 25.2 Interest cost 64.4 47.3 128.1 94.7 Expected return on plan assets ( 75.5 ) ( 92.5 ) ( 151.3 ) ( 185.0 ) Amortization of net actuarial loss 14.7 2.2 29.2 4.4 Amortization of prior service cost 1.9 2.1 4.0 4.2 Settlement loss — 0.2 — 0.2 Company defined benefit plan cost (income) 13.4 ( 28.0 ) 25.4 ( 56.3 ) Multiemployer and other plans 0.4 0.4 0.7 0.7 Net pension cost (income) $ 13.8 $ ( 27.6 ) $ 26.1 $ ( 55.6 ) The following table presents a summary of the components of the net postretirement cost (in millions): Three Months Ended Six Months Ended March 31, March 31, 2023 2022 2023 2022 Service cost $ 0.2 $ 0.2 $ 0.4 $ 0.5 Interest cost 1.8 1.6 3.6 3.1 Amortization of net actuarial gain ( 1.2 ) ( 0.4 ) ( 2.3 ) ( 0.8 ) Amortization of prior service credit ( 0.1 ) ( 0.2 ) ( 0.3 ) ( 0.4 ) Net postretirement cost $ 0.7 $ 1.2 $ 1.4 $ 2.4

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Mar. 31, 2023
Segment Reporting [Abstract]
Certain Operating Data for Segments	The tables in this Note 8 show selected financial data for our reportable segments (in millions): Three Months Ended Six Months Ended March 31, March 31, 2023 2022 2023 2022 Net sales (aggregate): Corrugated Packaging $ 2,627.4 $ 2,319.0 $ 4,964.8 $ 4,539.0 Consumer Packaging 1,265.1 1,250.6 2,480.1 2,389.3 Global Paper 1,168.2 1,538.1 2,291.8 2,890.7 Distribution 307.3 362.3 628.8 687.1 Total $ 5,368.0 $ 5,470.0 $ 10,365.5 $ 10,506.1 Less net sales (intersegment): Corrugated Packaging $ 81.6 $ 78.5 $ 150.0 $ 152.7 Consumer Packaging 7.5 6.9 12.2 12.9 Distribution 1.3 2.5 2.6 6.2 Total $ 90.4 $ 87.9 $ 164.8 $ 171.8 Net sales (unaffiliated customers): Corrugated Packaging $ 2,545.8 $ 2,240.5 $ 4,814.8 $ 4,386.3 Consumer Packaging 1,257.6 1,243.7 2,467.9 2,376.4 Global Paper 1,168.2 1,538.1 2,291.8 2,890.7 Distribution 306.0 359.8 626.2 680.9 Total $ 5,277.6 $ 5,382.1 $ 10,200.7 $ 10,334.3 Adjusted EBITDA: Corrugated Packaging $ 407.5 $ 328.7 $ 736.9 $ 617.6 Consumer Packaging 218.6 205.8 401.9 375.1 Global Paper 187.1 308.6 344.4 541.0 Distribution 9.3 28.0 20.1 34.5 Total 822.5 871.1 1,503.3 1,568.2 Depreciation, depletion and amortization ( 395.8 ) ( 373.6 ) ( 769.0 ) ( 740.1 ) Gain on sale of certain closed facilities 8.9 — 9.8 14.4 Multiemployer pension withdrawal income — — — 3.3 Restructuring and other costs ( 444.7 ) ( 363.4 ) ( 477.7 ) ( 365.7 ) Goodwill impairment ( 1,893.0 ) — ( 1,893.0 ) — Non-allocated expenses ( 33.9 ) ( 17.2 ) ( 62.6 ) ( 34.0 ) Interest expense, net ( 108.4 ) ( 72.5 ) ( 205.7 ) ( 159.2 ) Loss on extinguishment of debt — ( 8.2 ) — ( 8.2 ) Other (expense) income, net ( 17.8 ) 6.3 7.4 6.5 Other adjustments ( 59.4 ) — ( 179.0 ) ( 0.3 ) (Loss) income before income taxes $ ( 2,121.6 ) $ 42.5 $ ( 2,066.5 ) $ 284.9 Additional selected financial data (in millions): Three Months Ended Six Months Ended March 31, March 31, 2023 2022 2023 2022 Depreciation, depletion and amortization: Corrugated Packaging $ 211.2 $ 166.9 $ 403.4 $ 333.9 Consumer Packaging 85.5 90.1 169.6 176.4 Global Paper 91.2 109.8 180.3 216.0 Distribution 6.9 5.8 13.8 11.6 Corporate 1.0 1.0 1.9 2.2 Total $ 395.8 $ 373.6 $ 769.0 $ 740.1 Other adjustments: Corrugated Packaging $ 4.7 $ ( 6.4 ) $ 54.5 $ ( 6.4 ) Consumer Packaging 28.0 7.5 59.6 7.7 Global Paper 9.1 ( 1.1 ) 26.6 ( 1.0 ) Corporate 17.6 — 38.3 — Total $ 59.4 $ — $ 179.0 $ 0.3 Equity in income (loss) of unconsolidated entities: Corrugated Packaging $ 4.0 $ 20.6 $ ( 31.8 ) $ 35.6 Consumer Packaging — — — 3.4 Global Paper 0.5 — 0.3 — Total $ 4.5 $ 20.6 $ ( 31.5 ) $ 39.0 We allocate the assets and capital expenditures of our mill system across our reportable segments because the benefits of vertical integration are reflected in the reportable segment that ultimately sells the associated paper and packaging products to external customers. The following tables reflect such allocation (in millions): March 31, September 30, Assets: Corrugated Packaging $ 13,066.0 $ 11,382.5 Consumer Packaging 6,647.0 6,704.5 Global Paper 5,151.1 7,039.2 Distribution 813.5 863.0 Assets held for sale 169.2 34.4 Corporate 2,363.6 2,381.9 Total $ 28,210.4 $ 28,405.5 Intangibles, net: Corrugated Packaging $ 608.2 $ 648.4 Consumer Packaging 1,460.9 1,523.5 Global Paper 563.8 612.6 Distribution 126.2 136.1 Total $ 2,759.1 $ 2,920.6 Equity method investments: Corrugated Packaging $ 78.6 $ 479.3 Consumer Packaging 0.6 0.5 Global Paper 1.2 0.5 Corporate 0.1 0.1 Total $ 80.5 $ 480.4 Six Months Ended March 31, 2023 2022 Capital expenditures: Corrugated Packaging $ 241.7 $ 156.7 Consumer Packaging 125.5 67.9 Global Paper 144.1 108.8 Distribution 7.6 2.5 Corporate 44.8 18.2 Total $ 563.7 $ 354.1
Changes in Carrying Amount of Goodwill	The changes in the carrying amount of goodwill during the six months ended March 31, 2023 are as follows (in millions): Corrugated Consumer Global Paper Distribution Total Balance as of Sep. 30, 2022 $ 2,802.8 $ 1,588.4 $ 1,366.5 $ 137.5 $ 5,895.2 Goodwill impairment ( 514.3 ) — ( 1,378.7 ) — ( 1,893.0 ) Acquisitions 233.3 — — — 233.3 Divestitures — ( 7.4 ) ( 4.1 ) — ( 11.5 ) Transferred to assets held for sale — ( 24.9 ) — — ( 24.9 ) Translation and other adjustments 71.9 ( 35.4 ) 16.3 1.1 53.9 Balance as of Mar. 31, 2023 Goodwill $ 3,108.0 $ 1,520.7 $ 1,378.7 $ 138.6 $ 6,146.0 Accumulated impairment losses ( 514.3 ) — ( 1,378.7 ) — ( 1,893.0 ) $ 2,593.7 $ 1,520.7 $ - $ 138.6 $ 4,253.0

Interest Expense, Net (Tables)

Interest Expense, Net (Tables)	6 Months Ended
	Mar. 31, 2023
Interest Income (Expense), Net [Abstract]
Summary of Components of Interest Expense, Net	The components of interest expense, net are as follows (in millions): Three Months Ended Six Months Ended March 31, March 31, 2023 2022 2023 2022 Interest expense $ ( 134.3 ) $ ( 84.9 ) $ ( 253.2 ) $ ( 183.2 ) Interest income 25.9 12.4 47.5 24.0 Interest expense, net $ ( 108.4 ) $ ( 72.5 ) $ ( 205.7 ) $ ( 159.2 )

Inventories (Tables)

Inventories (Tables)	6 Months Ended
	Mar. 31, 2023
Inventory Disclosure [Abstract]
Schedule of Inventories	The components of inventories were as follows (in millions): March 31, September 30, Finished goods and work in process $ 1,187.4 $ 1,102.4 Raw materials 1,234.2 1,135.9 Spare parts and supplies 568.8 529.6 Inventories at FIFO cost 2,990.4 2,767.9 LIFO reserve ( 440.1 ) ( 450.8 ) Net inventories $ 2,550.3 $ 2,317.1

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	6 Months Ended
	Mar. 31, 2023
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	The components of property, plant and equipment were as follows (in millions): March 31, September 30, Property, plant and equipment at cost: Land and buildings $ 3,101.4 $ 2,646.4 Machinery and equipment 17,970.4 16,592.5 Forestlands 100.8 95.7 Transportation equipment 23.3 24.2 Leasehold improvements 104.9 103.4 21,300.8 19,462.2 Less: accumulated depreciation, depletion and ( 10,137.8 ) ( 9,380.8 ) Property, plant and equipment, net $ 11,163.0 $ 10,081.4

Fair Value (Tables)

Fair Value (Tables)	6 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Summary of Accounts Receivable Sales Agreement	The following table presents a summary of these accounts receivable sales agreements for the six months ended March 31, 2023 and March 31, 2022 (in millions): Six Months Ended March 31, 2023 2022 Receivable from financial institutions at beginning of fiscal year $ — $ — Receivables sold to the financial institutions and derecognized ( 1,426.9 ) ( 1,454.3 ) Receivables collected by financial institutions 1,432.0 1,410.9 Cash (payments to) proceeds from financial institutions ( 5.1 ) 43.4 Receivable from financial institutions at March 31 $ — $ —

Debt (Tables)

Debt (Tables)	6 Months Ended
	Mar. 31, 2023
Debt [Abstract]
Schedule of Carrying Value of Individual Components of Debt	The following table shows the carrying value of the individual components of our debt (in millions): March 31, 2023 September 30, 2022 Public bonds due fiscal 2024 to 2028 $ 3,435.6 $ 3,433.4 Public bonds due fiscal 2029 to 2033 2,746.5 2,753.3 Public bonds due fiscal 2037 to 2047 177.5 177.8 Revolving credit and swing facilities 218.1 286.3 Term loan facilities 1,597.1 598.2 Receivables securitization 375.0 — Commercial paper 291.4 — International and other debt 125.0 127.6 Finance lease obligations 410.9 287.5 Vendor financing and commercial card 128.5 123.1 Total debt 9,505.6 7,787.2 Less: current portion of debt 501.6 212.2 Long-term debt due after one year $ 9,004.0 $ 7,575.0

Leases (Tables)

Leases (Tables)	6 Months Ended
	Mar. 31, 2023
Leases [Abstract]
Summary of Supplemental Balance Sheet Information Related to Leases	Supplemental Balance Sheet Information Related to Leases The table below presents supplemental balance sheet information related to leases (in millions): Consolidated Balance March 31, September 30, Operating leases: Operating lease right-of-use asset Other noncurrent assets $ 657.3 $ 699.6 Current operating lease liabilities Other current liabilities $ 198.6 $ 191.9 Noncurrent operating lease liabilities Other noncurrent liabilities 505.7 551.1 Total operating lease liabilities $ 704.3 $ 743.0 Finance leases: Property, plant and equipment $ 314.8 $ 177.4 Accumulated depreciation ( 49.5 ) ( 37.3 ) Property, plant and equipment, net $ 265.3 $ 140.1 Current finance lease liabilities Current portion of debt $ 22.3 $ 14.5 Noncurrent finance lease liabilities Long-term debt due after one year 388.6 273.0 Total finance lease liabilities $ 410.9 $ 287.5

Derivatives (Tables)

Derivatives (Tables)	6 Months Ended
	Mar. 31, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary Of Outstanding Notional Amounts	The following table sets forth the outstanding notional amounts related to our derivative instruments (in millions): Metric March 31, September 30, Designated cash flow hedges: Natural gas commodity contracts MMBtu 21.3 18.3 Undesignated derivatives: Foreign currency contracts (1) Mexican pesos — 8,000.0 At September 30, 2022, the outstanding foreign currency exchange contract was related to the purchase of 8.0 billion Mexican pesos ($ 389.9 million) for refinancing Grupo Gondi's external debt upon the Grupo Gondi Acquisition on December 1, 2022 .
Summary of Location and Fair Values of Derivative Instruments	The following table sets forth the l ocation and fair values of our derivative instruments (in millions): Consolidated Balance March 31, September 30, Designated cash flow hedges: Natural gas commodity contracts Other current liabilities (1) $ 32.3 $ 12.0 Undesignated derivatives: Foreign currency contracts Other current assets $ — $ 3.4 (1) At September 30, 2022, liability positions by counterparty were partially offset by $ 2.3 million of asset positions where we had an enforceable right of netting.
Summary of Gains (Losses) Recognized in Accumulated Other Comprehensive Loss, Net of Tax for Cash Flow Hedges	The following table sets forth gains (losses) recognized in accumulated other comprehensive loss, net of tax for cash flow hedges (in millions): Three Months Ended Six Months Ended March 31, March 31, 2023 2022 2023 2022 Natural gas commodity contracts $ ( 3.4 ) $ — $ ( 15.3 ) $ —
Summary of Gains (Losses) Recognized in the Statements of Income	The following table sets forth amounts of gains (losses) recognized in the consolidated statements of operations for cash flow hedges reclassified from accumulated other comprehensive loss (in millions): Three Months Ended Six Months Ended March 31, March 31, Consolidated Statement 2023 2022 2023 2022 Natural gas commodity contracts Cost of goods sold $ ( 26.8 ) $ — $ ( 40.0 ) $ — The following table sets forth amounts of gains (losses) recognized in the consolidated statements of operations for derivatives not designated as hedges (in millions): Three Months Ended Six Months Ended March 31, March 31, Consolidated Statement 2023 2022 2023 2022 Foreign currency contracts Other (expense) income, net $ — $ — $ 19.7 $ —

Special Purpose Entities (Table

Special Purpose Entities (Tables)	6 Months Ended
	Mar. 31, 2023
Special Purpose Entities [Abstract]
Schedule of Restricted Assets and Non-recourse Liabilities Held by Special Purposes Entities	The restricted assets and non-recourse liabilities held by special purpose entities are included in the consolidated balance sheets in the following (in millions): March 31, September 30, Other current assets $ 867.9 $ — Other noncurrent assets $ 381.1 $ 1,253.0 Other current liabilities $ 782.5 $ — Other noncurrent liabilities $ 330.2 $ 1,117.8

Equity and Other Comprehensiv_2

Equity and Other Comprehensive Income (Loss) (Tables)	6 Months Ended
	Mar. 31, 2023
Equity [Abstract]
Schedule of Changes in Accumulated Other Comprehensive Loss, Net of Tax	The tables below summarize the changes in accumulated other comprehensive loss, net of tax, by component for the six months ended March 31, 2023 and March 31, 2022 (in millions): Deferred (Loss) Income on Cash Defined Benefit Foreign Total (1) Balance at September 30, 2022 $ ( 9.1 ) $ ( 741.6 ) $ ( 703.6 ) $ ( 1,454.3 ) Other comprehensive (loss) income before ( 45.3 ) — 299.7 254.4 Amounts reclassified from accumulated other 30.0 22.4 29.0 81.4 Net current period other comprehensive (loss) income ( 15.3 ) 22.4 328.7 335.8 Balance at March 31, 2023 $ ( 24.4 ) $ ( 719.2 ) $ ( 374.9 ) $ ( 1,118.5 ) (1) All amounts are net of tax and noncontrolling interests. Deferred (Loss) Income on Cash Defined Benefit Foreign Total (1) Balance at September 30, 2021 $ ( 0.2 ) $ ( 536.5 ) $ ( 462.4 ) $ ( 999.1 ) Other comprehensive income before — 0.1 113.4 113.5 Amounts reclassified from accumulated other — 5.4 — 5.4 Net current period other comprehensive income — 5.5 113.4 118.9 Balance at March 31, 2022 $ ( 0.2 ) $ ( 531.0 ) $ ( 349.0 ) $ ( 880.2 ) (1) All amounts are net of tax and noncontrolling interests.
Summary of Reclassification out of Accumulated Other Comprehensive Loss	The following table summarizes the reclassifications out of accumulated other comprehensive loss by component (in millions): Three Months Ended Three Months Ended March 31, 2023 March 31, 2022 Pre-tax Tax Net of Tax Pre-tax Tax Net of Tax Amortization of defined benefit pension and (1) Actuarial losses (2) $ ( 13.2 ) $ 3.3 $ ( 9.9 ) $ ( 1.9 ) $ 0.5 $ ( 1.4 ) Prior service costs (2) ( 1.9 ) 0.5 ( 1.4 ) ( 1.9 ) 0.5 ( 1.4 ) Subtotal defined benefit plans ( 15.1 ) 3.8 ( 11.3 ) ( 3.8 ) 1.0 ( 2.8 ) Derivative Instruments: (1) Natural gas commodity hedge loss (3) ( 26.8 ) 6.7 ( 20.1 ) — — — Total reclassifications for the period $ ( 41.9 ) $ 10.5 $ ( 31.4 ) $ ( 3.8 ) $ 1.0 $ ( 2.8 ) (1) Amounts in parentheses indicate charges to earnings. Amounts pertaining to noncontrolling interests are excluded. (2) Included in the computation of net periodic pension cost. See “ Note 6. Retirement Plans ” for additional details. (3) These accumulated other comprehensive loss components are included in Cost of goods sold. Six Months Ended Six Months Ended March 31, 2023 March 31, 2022 Pre-tax Tax Net of Tax Pre-tax Tax Net of Tax Amortization of defined benefit pension and (1) Actuarial losses (2) $ ( 26.5 ) $ 6.9 $ ( 19.6 ) $ ( 3.5 ) $ 0.9 $ ( 2.6 ) Prior service costs (2) ( 3.8 ) 1.0 ( 2.8 ) ( 3.8 ) 1.0 ( 2.8 ) Subtotal defined benefit plans ( 30.3 ) 7.9 ( 22.4 ) ( 7.3 ) 1.9 ( 5.4 ) Foreign currency translation adjustments: (1) Recognition of previously unrealized (3) ( 29.0 ) — ( 29.0 ) — — — Derivative Instruments: (1) Natural gas commodity hedge loss (4) ( 40.0 ) 10.0 ( 30.0 ) — — — Total reclassifications for the period $ ( 99.3 ) $ 17.9 $ ( 81.4 ) $ ( 7.3 ) $ 1.9 $ ( 5.4 ) (1) Amounts in parentheses indicate charges to earnings. Amounts pertaining to noncontrolling interests are excluded. (2) Included in the computation of net periodic pension cost. See “ Note 6. Retirement Plans ” for additional details. (3) Amount reflected in Equity in income (loss) of unconsolidated entities in the consolidated statements of operations. (4) These accumulated other comprehensive loss components are included in Cost of goods sold.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Mar. 31, 2023
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table sets forth the computation of basic and diluted earnings per share under the two-class method (in millions, except per share data): Three Months Ended Six Months Ended March 31, March 31, 2023 2022 2023 2022 Numerator: Net (loss) income attributable to common $ ( 2,006.1 ) $ 39.9 $ ( 1,960.8 ) $ 222.2 Less: Distributed and undistributed income — ( 0.1 ) — ( 0.1 ) Distributed and undistributed (loss) income $ ( 2,006.1 ) $ 39.8 $ ( 1,960.8 ) $ 222.1 Denominator: Basic weighted average shares outstanding 255.6 263.4 255.2 264.0 Effect of dilutive stock options and non- — 1.9 — 2.1 Diluted weighted average shares outstanding 255.6 265.3 255.2 266.1 Basic (loss) earnings per share attributable to $ ( 7.85 ) $ 0.15 $ ( 7.68 ) $ 0.84 Diluted (loss) earnings per share attributable to $ ( 7.85 ) $ 0.15 $ ( 7.68 ) $ 0.83

Basis of Presentation and Sig_3

Basis of Presentation and Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Millions		1 Months Ended	3 Months Ended		6 Months Ended	12 Months Ended
	Dec. 01, 2022	Nov. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2023	Sep. 30, 2022	Sep. 30, 2021
Basis of Presentation and Significant Accounting Policies [Line Items]
Gain on sale of businesses					$ 11.1
Business interruption recovery related to ransomware incident			$ 5	$ 5
Gain on Business Interruption Insurance Recovery, Statement of Income or Comprehensive Income [Extensible Enumeration]			Cost of Goods and Services Sold	Cost of Goods and Services Sold
Ransomware other recoveries						$ 57.2	$ 15
Eaton, IN, and Aurora, IL [Member]
Basis of Presentation and Significant Accounting Policies [Line Items]
Sale of uncoated recycled paperboard mills subject to working capital adjustment	$ 50
Sale proceeds received	25
Preliminary working capital settlement	0.9
Amount financed	25
Gain on sale of businesses	$ 11.1
Grupo Gondi [Member]
Basis of Presentation and Significant Accounting Policies [Line Items]
Date of acquisition	Dec. 01, 2022
Percentage of remaining interest acquired	67.70%
Cash payment to acquire businesses	$ 969.8
RTS Packaging, LLC [Member] | Chattanooga, TN [Member]
Basis of Presentation and Significant Accounting Policies [Line Items]
Planned sale of interior partitions converting operations and Chattanooga mill subject to working capital adjustment		$ 330
Transaction expected to close subject to satisfaction of closing conditions		2023
Accounting Standards Update 2021-10 [Member]
Basis of Presentation and Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted					true
Change in accounting principle, accounting standards update, adoption date					Oct. 01, 2022
Change in accounting principle, accounting standards update, immaterial effect					true
Accounting Standards Update 2021-08 [Member]
Basis of Presentation and Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted					true
Change in accounting principle, accounting standards update, adoption date					Oct. 01, 2022
Change in accounting principle, accounting standards update, immaterial effect					true
Accounting Standards Update 2020-04 [Member]
Basis of Presentation and Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted					true
Change in accounting principle, accounting standards update, adoption date					Oct. 01, 2022
Change in accounting principle, accounting standards update, immaterial effect					true

Revenue Recognition -Schedule o

Revenue Recognition -Schedule of Disaggregates Revenue by Primary Geographical Markets (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Mar. 31, 2023		Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Disaggregation Of Revenue [Line Items]
Net sales	$ 5,277.6		$ 5,382.1	$ 10,200.7	$ 10,334.3
Corrugated Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	2,627.4		2,319	4,964.8	4,539
Consumer Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	1,265.1		1,250.6	2,480.1	2,389.3
Global Paper [Member]
Disaggregation Of Revenue [Line Items]
Net sales	1,168.2		1,538.1	2,291.8	2,890.7
Distribution Segment [Member]
Disaggregation Of Revenue [Line Items]
Net sales	307.3		362.3	628.8	687.1
Intersegment Sales [Member]
Disaggregation Of Revenue [Line Items]
Net sales	(90.4)		(87.9)	(164.8)	(171.8)
Intersegment Sales [Member] | Corrugated Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	(81.6)		(78.5)	(150)	(152.7)
Intersegment Sales [Member] | Consumer Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	(7.5)		(6.9)	(12.2)	(12.9)
Intersegment Sales [Member] | Distribution Segment [Member]
Disaggregation Of Revenue [Line Items]
Net sales	(1.3)		(2.5)	(2.6)	(6.2)
U.S. [Member]
Disaggregation Of Revenue [Line Items]
Net sales	3,975.3		4,397.7	7,879.7	8,430.3
U.S. [Member] | Corrugated Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	2,001.6		2,068.1	3,975.1	4,037.1
U.S. [Member] | Consumer Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	741.7		720	1,444.7	1,368.3
U.S. [Member] | Global Paper [Member]
Disaggregation Of Revenue [Line Items]
Net sales	1,056.3		1,376.3	2,079	2,589.4
U.S. [Member] | Distribution Segment [Member]
Disaggregation Of Revenue [Line Items]
Net sales	260.3		319.1	537	603.7
U.S. [Member] | Intersegment Sales [Member]
Disaggregation Of Revenue [Line Items]
Net sales	(84.6)		(85.8)	(156.1)	(168.2)
Canada [Member]
Disaggregation Of Revenue [Line Items]
Net sales	327.9		338.3	636.1	653.1
Canada [Member] | Corrugated Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	138		145.9	275.1	286.3
Canada [Member] | Consumer Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	134.5		128.4	258.2	242.7
Canada [Member] | Global Paper [Member]
Disaggregation Of Revenue [Line Items]
Net sales	54.4		62.2	99.9	120.1
Canada [Member] | Distribution Segment [Member]
Disaggregation Of Revenue [Line Items]
Net sales	2.8		3.8	6.2	7.3
Canada [Member] | Intersegment Sales [Member]
Disaggregation Of Revenue [Line Items]
Net sales	(1.8)		(2)	(3.3)	(3.3)
Latin America [Member]
Disaggregation Of Revenue [Line Items]
Net sales	573		257.3	923.9	495.3
Latin America [Member] | Corrugated Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	485		104.7	710.5	212.3
Latin America [Member] | Consumer Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	12.5		48.3	64.2	93.8
Latin America [Member] | Global Paper [Member]
Disaggregation Of Revenue [Line Items]
Net sales	35.1		65	68.7	113.3
Latin America [Member] | Distribution Segment [Member]
Disaggregation Of Revenue [Line Items]
Net sales	44.2		39.4	85.6	76.1
Latin America [Member] | Intersegment Sales [Member]
Disaggregation Of Revenue [Line Items]
Net sales	(3.8)		(0.1)	(5.1)	(0.2)
EMEA [Member]
Disaggregation Of Revenue [Line Items]
Net sales	318.5	[1]	294.9	590.7	565.8
EMEA [Member] | Corrugated Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	2.8	[1]	0.3	4.1	3.3
EMEA [Member] | Consumer Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	304.5	[1]	277	564.4	529.1
EMEA [Member] | Global Paper [Member]
Disaggregation Of Revenue [Line Items]
Net sales	11.4	[1]	17.6	22.5	33.5
EMEA [Member] | Intersegment Sales [Member]
Disaggregation Of Revenue [Line Items]
Net sales	(0.2)	[1]		(0.3)	(0.1)
Asia Pacific [Member]
Disaggregation Of Revenue [Line Items]
Net sales	82.9		93.9	170.3	189.8
Asia Pacific [Member] | Consumer Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	71.9		76.9	148.6	155.4
Asia Pacific [Member] | Global Paper [Member]
Disaggregation Of Revenue [Line Items]
Net sales	$ 11		$ 17	$ 21.7	$ 34.4
[1] Europe, Middle East and Africa ("EMEA")

Revenue Recognition - Summary o

Revenue Recognition - Summary of Opening and Closing Balances of Contract Assets and Contract Liabilities (Details) $ in Millions	6 Months Ended
	Mar. 31, 2023 USD ($)
Disaggregation of Revenue [Abstract]
Short-Term Contract Assets, Beginning balance	$ 244
Increase in Short-Term Contract Assets	13.9
Short-Term Contract Assets, Ending balance	257.9
Short-Term Contract Liabilities, Beginning balance	13.9
Increase (Decrease) in Short-Term Contract Liabilities	(1.6)
Short-Term Contract Liabilities, Ending balance	$ 12.3

Acquisitions - Additional Infor

Acquisitions - Additional Information (Details) - Grupo Gondi [Member] $ in Millions	Dec. 01, 2022 USD ($) GraphicPlants PaperMills CorrugatedPackagingPlants
Business Acquisition [Line Items]
Date of acquisition	Dec. 01, 2022
Percentage of remaining interest acquired	67.70%
Acquisition date fair value	$ 403.7
Percentage of ownership interest previously held	32.30%
Non-cash pre-tax loss	$ 46.8
Loss after release of related deferred tax liability	$ 24.6
Step acquisition percentage of control	100%
Mexico [Member]
Business Acquisition [Line Items]
Number of paper mills | PaperMills	4
Number of corrugated packaging plants | CorrugatedPackagingPlants	9
Number of high graphic plants | GraphicPlants	6

Acquisitions - Summary of Purch

Acquisitions - Summary of Purchase Consideration Transferred (Details) - Grupo Gondi [Member] $ in Millions	Dec. 01, 2022 USD ($)
Business Acquisition [Line Items]
Cash consideration transferred for 67.7% interest	$ 969.8
Fair value of the previously held interest	403.7
Settlement of preexisting relationships (net receivable from Grupo Gondi)	40.2
Purchase consideration transferred	$ 1,413.7

Acquisitions - Summary of Pur_2

Acquisitions - Summary of Purchase Consideration Transferred (Parenthetical) (Details)	Dec. 01, 2022
Grupo Gondi [Member]
Business Acquisition [Line Items]
Percentage of remaining interest acquired	67.70%

Acquisitions - Summary of Preli

Acquisitions - Summary of Preliminary Fair Value of Assets and Liabilities Assumed in Acquisition (Details) - USD ($) $ in Millions		Mar. 31, 2023	Dec. 01, 2022	Sep. 30, 2022
Business Acquisition [Line Items]
Goodwill		$ 4,253		$ 5,895.2
Grupo Gondi [Member]
Business Acquisition [Line Items]
Cash and cash equivalents			$ 116.3
Current assets, excluding cash and cash equivalents			697
Property, plant and equipment			1,380.3
Goodwill			231.2
Other noncurrent assets			101.4
Total assets acquired			2,526.2
Current portion of debt	[1]		13.2
Current liabilities, excluding debt			384.8
Long-term debt due after one year	[1]		591.4
Pension liabilities, net of current portion			35.2
Deferred Income Taxes			69.8
Other noncurrent liabilities			18.1
Total liabilities assumed			1,112.5
Net assets acquired			1,413.7
Measurement Period Adjustments [Member] | Grupo Gondi [Member]
Business Acquisition [Line Items]
Current assets, excluding cash and cash equivalents	[2]		(1.6)
Property, plant and equipment	[2]		15.2
Goodwill	[2]		2.1
Other noncurrent assets	[2]		(0.1)
Total assets acquired	[2]		15.6
Current portion of debt	[1],[2]		0.5
Current liabilities, excluding debt	[2]		0.4
Long-term debt due after one year	[1],[2]		14.7
Total liabilities assumed	[2]		15.6
As Adjusted [Member] | Grupo Gondi [Member]
Business Acquisition [Line Items]
Cash and cash equivalents	[3]		116.3
Current assets, excluding cash and cash equivalents	[3]		695.4
Property, plant and equipment	[3]		1,395.5
Goodwill	[3]		233.3
Other noncurrent assets	[3]		101.3
Total assets acquired	[3]		2,541.8
Current portion of debt	[1],[3]		13.7
Current liabilities, excluding debt	[3]		385.2
Long-term debt due after one year	[1],[3]		606.1
Pension liabilities, net of current portion	[3]		35.2
Deferred Income Taxes	[3]		69.8
Other noncurrent liabilities	[3]		18.1
Total liabilities assumed	[3]		1,128.1
Net assets acquired	[3]		$ 1,413.7
[1] Includes $ 494.8 million of Grupo Gondi debt that we assumed and repa id in connection with th e closing of the Grupo Gondi Acquisition. The remaining balance relates to current and long-term portions of finance leases. The measurement period adjustments recorded in fiscal 2023 did not have a significant impact on our consolidated statements of operations for the three and six months ended March 31, 2023. The measurement period adjustments were primarily due to refinements to the carrying amounts of certain assets and liabilities. The net impact of the measurement period adjustments resulted in a net increase in goodwill.

Acquisitions - Summary of Pre_2

Acquisitions - Summary of Preliminary Fair Preliminary Value of Assets and Liabilities Assumed in Acquisition (Parenthetical) (Details) - USD ($) $ in Millions		6 Months Ended
	Dec. 01, 2022	Mar. 31, 2023	Mar. 31, 2022
Business Acquisition [Line Items]
Debt assumed and repaid		$ 516.7	$ 416.2
Grupo Gondi [Member]
Business Acquisition [Line Items]
Debt assumed and repaid	$ 494.8

Held For Sale - Additional Info

Held For Sale - Additional Information (Details) - USD ($) $ in Millions	1 Months Ended
	Nov. 30, 2022	Mar. 31, 2023	Sep. 30, 2022
Long-Lived Assets Held-for-sale [Line Items]
Net assets and liabilities held for sale		$ 103.4	$ 34.4
Net assets held for sale related to closed facilities		32.3	$ 34.4
Chattanooga, TN [Member] | R T S Packaging, L L C [Member]
Long-Lived Assets Held-for-sale [Line Items]
Planned sale of interior partitions converting operations and Chattanooga mill subject to working capital adjustment	$ 330
Transaction expected to close subject to satisfaction of closing conditions	2023
Net assets held for sale for divesture		71.1
Goodwill held for sale		24.9
Property, plant and equipment, net held for sale		$ 42

Restructuring and Other Costs -

Restructuring and Other Costs - Additional Information (Details) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Mar. 31, 2023 USD ($) T	Mar. 31, 2022 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring and other costs	$ 444.7	$ 363.4	$ 477.7	$ 365.7
Restructuring and other costs, noncash			346.5	322.1
Restructuring costs	441.2	362.9	$ 457.5	$ 365
Panama City Mill [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs		$ 355.1
North Charleston [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 415.3
Annual capacity of production | T			550,000

Restructuring and Other Costs_2

Restructuring and Other Costs - Schedule of Restructuring and Other Costs (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Restructuring and Related Activities [Abstract]
Restructuring	$ 441.2	$ 362.9	$ 457.5	$ 365
Other	3.5	0.5	20.2	0.7
Restructuring and other costs	$ 444.7	$ 363.4	$ 477.7	$ 365.7

Restructuring and Other Costs_3

Restructuring and Other Costs - Schedule of Restructuring Charges Related to Active Restructuring Initiatives (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	$ 441.2	$ 362.9	$ 457.5	$ 365
Restructuring and Related Cost, Cost Incurred to Date	934.7		934.7
Restructuring and Related Cost, Expected Cost	1,096.8		1,096.8
PP&E and Related Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	348.5	344.7	347.8	345.6
Restructuring and Related Cost, Cost Incurred to Date	736.9		736.9
Restructuring and Related Cost, Expected Cost	736.9		736.9
Severance and Other Employee Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	27.8	16.4	37.9	17.8
Restructuring and Related Cost, Cost Incurred to Date	87.9		87.9
Restructuring and Related Cost, Expected Cost	97.2		97.2
Other Restructuring Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	64.9	1.8	71.8	1.6
Restructuring and Related Cost, Cost Incurred to Date	109.9		109.9
Restructuring and Related Cost, Expected Cost	262.7		262.7
Corrugated Packaging [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	8	4.5	9.8	4.4
Restructuring and Related Cost, Cost Incurred to Date	29.3		29.3
Restructuring and Related Cost, Expected Cost	35.2		35.2
Corrugated Packaging [Member] | PP&E and Related Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	4.3		4.3
Restructuring and Related Cost, Cost Incurred to Date	8		8
Restructuring and Related Cost, Expected Cost	8		8
Corrugated Packaging [Member] | Severance and Other Employee Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	3.6	4.4	5.3	4
Restructuring and Related Cost, Cost Incurred to Date	15		15
Restructuring and Related Cost, Expected Cost	15		15
Corrugated Packaging [Member] | Other Restructuring Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0.1	0.1	0.2	0.4
Restructuring and Related Cost, Cost Incurred to Date	6.3		6.3
Restructuring and Related Cost, Expected Cost	12.2		12.2
Consumer Packaging [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	2	1.4	8.1	3.2
Restructuring and Related Cost, Cost Incurred to Date	45.5		45.5
Restructuring and Related Cost, Expected Cost	45.5		45.5
Consumer Packaging [Member] | PP&E and Related Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	2.2		2.2
Restructuring and Related Cost, Expected Cost	2.2		2.2
Consumer Packaging [Member] | Severance and Other Employee Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	2.2	1.3	8.6	3.1
Restructuring and Related Cost, Cost Incurred to Date	33.5		33.5
Restructuring and Related Cost, Expected Cost	33.5		33.5
Consumer Packaging [Member] | Other Restructuring Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	(0.2)	0.1	(0.5)	0.1
Restructuring and Related Cost, Cost Incurred to Date	9.8		9.8
Restructuring and Related Cost, Expected Cost	9.8		9.8
Global Paper [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	426.3	355.1	431	355.1
Restructuring and Related Cost, Cost Incurred to Date	831		831
Restructuring and Related Cost, Expected Cost	987.2		987.2
Global Paper [Member] | PP&E and Related Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	344	344.4	342.9	344.4
Restructuring and Related Cost, Cost Incurred to Date	715.3		715.3
Restructuring and Related Cost, Expected Cost	715.3		715.3
Global Paper [Member] | Severance and Other Employee Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	19.3	10.7	19.1	10.7
Restructuring and Related Cost, Cost Incurred to Date	30.5		30.5
Restructuring and Related Cost, Expected Cost	39.8		39.8
Global Paper [Member] | Other Restructuring Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	63		69
Restructuring and Related Cost, Cost Incurred to Date	85.2		85.2
Restructuring and Related Cost, Expected Cost	232.1		232.1
Distribution [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	1.1		1.1
Restructuring and Related Cost, Cost Incurred to Date	2.2		2.2
Restructuring and Related Cost, Expected Cost	2.2		2.2
Distribution [Member] | Severance and Other Employee Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	1		1
Restructuring and Related Cost, Cost Incurred to Date	1.1		1.1
Restructuring and Related Cost, Expected Cost	1.1		1.1
Distribution [Member] | Other Restructuring Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0.1		0.1
Restructuring and Related Cost, Cost Incurred to Date	1.1		1.1
Restructuring and Related Cost, Expected Cost	1.1		1.1
Corporate, Non-Segment [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	3.8	1.9	7.5	2.3
Restructuring and Related Cost, Cost Incurred to Date	26.7		26.7
Restructuring and Related Cost, Expected Cost	26.7		26.7
Corporate, Non-Segment [Member] | PP&E and Related Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0.2	0.3	0.6	1.2
Restructuring and Related Cost, Cost Incurred to Date	11.4		11.4
Restructuring and Related Cost, Expected Cost	11.4		11.4
Corporate, Non-Segment [Member] | Severance and Other Employee Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	1.7		3.9
Restructuring and Related Cost, Cost Incurred to Date	7.8		7.8
Restructuring and Related Cost, Expected Cost	7.8		7.8
Corporate, Non-Segment [Member] | Other Restructuring Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	1.9	$ 1.6	3	$ 1.1
Restructuring and Related Cost, Cost Incurred to Date	7.5		7.5
Restructuring and Related Cost, Expected Cost	$ 7.5		$ 7.5

Restructuring and Other Costs_4

Restructuring and Other Costs - Schedule of Acquisition, Integration and Divestiture Costs (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Restructuring Cost And Reserve [Line Items]
Acquisition costs	$ 1.2	$ 0.2	$ 12.2	$ 0.4
Integration costs	1.8	0.2	6.1	0.2
Divestiture costs	0.5	0.1	1.9	0.1
Other total	$ 3.5	$ 0.5	$ 20.2	$ 0.7

Restructuring and Other Costs_5

Restructuring and Other Costs - Schedule of Changes in Restructuring Accrual Charges (Details) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Restructuring And Other Costs [Abstract]
Accrual at beginning of fiscal year	$ 25.2	$ 13.4
Additional accruals	40.2	17.6
Payments	(18.9)	(4)
Adjustment to accruals	(2.5)	(0.3)
Accrual at March 31	$ 44	$ 26.7

Restructuring and Other Costs_6

Restructuring and Other Costs - Schedule of Reconciliation of Accruals and Charges (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Restructuring And Other Costs [Abstract]
Additional accruals and adjustments to accruals (see table above)			$ 37.7	$ 17.3
PP&E and related costs			347.8	345.6
Severance and other employee costs			0.2	0.5
Acquisition costs	$ 1.2	$ 0.2	12.2	0.4
Integration costs	1.8	0.2	6.1	0.2
Divestiture costs	0.5	0.1	1.9	0.1
Other restructuring costs			71.8	1.6
Restructuring and other costs	$ 444.7	$ 363.4	$ 477.7	$ 365.7

Retirement Plans - Additional I

Retirement Plans - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022	Sep. 30, 2022
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Multiemployer Plans, Withdrawal Obligation	$ 213.1		$ 213.1		$ 214.7
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions by employer to pension and supplemental retirement plans	7.4	$ 6.2	15	$ 10.3
Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions by employer to pension and supplemental retirement plans	$ 2.1	$ 1.9	$ 3.6	$ 3.1

Retirement Plans - Summary of C

Retirement Plans - Summary of Components of Net Pension Income and Summary of Components of Postretirement Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 7.9	$ 12.7	$ 15.4	$ 25.2
Interest cost	64.4	47.3	128.1	94.7
Expected return on plan assets	$ (75.5)	$ (92.5)	$ (151.3)	$ (185)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component
Amortization of net actuarial loss (gain)	$ 14.7	$ 2.2	$ 29.2	$ 4.4
Amortization of prior service cost (credit)	$ 1.9	2.1	$ 4	4.2
Settlement loss		$ 0.2		$ 0.2
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Amortization of Prior Service Cost (Credit), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Settlement Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component
Company defined benefit plan cost (income)	$ 13.4	$ (28)	$ 25.4	$ (56.3)
Multiemployer and other plans	0.4	0.4	0.7	0.7
Net pension cost (income)	13.8	(27.6)	26.1	(55.6)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.2	0.2	0.4	0.5
Interest cost	1.8	1.6	3.6	3.1
Amortization of net actuarial loss (gain)	(1.2)	(0.4)	(2.3)	(0.8)
Amortization of prior service cost (credit)	$ (0.1)	$ (0.2)	$ (0.3)	$ (0.4)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Amortization of Prior Service Cost (Credit), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component
Net pension cost (income)	$ 0.7	$ 1.2	$ 1.4	$ 2.4

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Effective tax rates	5.50%	4.20%	5.30%	21.20%
Income taxes, cash paid net			$ 86.2	$ 55.8

Segment Information - Additiona

Segment Information - Additional Information (Details) $ in Millions		3 Months Ended	6 Months Ended
	Dec. 01, 2022 USD ($)	Mar. 31, 2023 USD ($)	Mar. 31, 2023 USD ($) Segment	Sep. 30, 2022 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | Segment			4
Goodwill impairment loss		$ 1,893	$ 1,893
Goodwill impairment loss after tax		1,829.8
Goodwill		$ 4,253	4,253	$ 5,895.2
Minimum [Member]
Segment Reporting Information [Line Items]
Reporting unit, discount rate		9.50%
Reporting unit, growth rate		0%
Maximum [Member]
Segment Reporting Information [Line Items]
Reporting unit, discount rate		13.50%
Reporting unit, growth rate		1%
Grupo Gondi [Member]
Segment Reporting Information [Line Items]
Non-cash pre-tax loss	$ 46.8
Loss after release of related deferred tax liability	24.6
Goodwill	$ 231.2
Corrugated Packaging [Member]
Segment Reporting Information [Line Items]
Acquisition accounting inventory-related adjustments		$ 4.6	7.6
Goodwill impairment loss		514.3
Goodwill		2,593.7	2,593.7
Corrugated Packaging [Member] | Grupo Gondi [Member]
Segment Reporting Information [Line Items]
Non-cash pre-tax loss			46.8
Consumer Packaging [Member]
Segment Reporting Information [Line Items]
Incremental work stoppage costs at Mahrt Mill		$ 27.2	58.5
Reporting unit percentage of fair value in excess of approximate carrying value		23%
Increase in discount rate to estimate fair values of reporting unit		1%
Goodwill		$ 1,520.7	1,520.7
Distribution [Member]
Segment Reporting Information [Line Items]
Reporting unit percentage of fair value in excess of approximate carrying value		15%
Increase in discount rate to estimate fair values of reporting unit		1%
Goodwill		$ 138.6	138.6
Global Paper [Member]
Segment Reporting Information [Line Items]
Incremental work stoppage costs at Mahrt Mill		9	19.3
Acquisition accounting inventory-related adjustments			5.5
Goodwill impairment loss		1,378.7
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Business systems transformation costs		$ 17.5	$ 37.7

Segment Information - Certain O

Segment Information - Certain Operating Data for Segments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022	Sep. 30, 2022
Segment Reporting Information [Line Items]
Net sales	$ 5,277.6	$ 5,382.1	$ 10,200.7	$ 10,334.3
Adjusted EBITDA	822.5	871.1	1,503.3	1,568.2
Depreciation, depletion and amortization	(395.8)	(373.6)	(769)	(740.1)
Gain on sale of certain closed facilities	8.9		9.8	14.4
Multiemployer pension withdrawal income				3.3
Restructuring and other costs	(444.7)	(363.4)	(477.7)	(365.7)
Goodwill impairment	(1,893)		(1,893)
Non-allocated expenses	(33.9)	(17.2)	(62.6)	(34)
Interest expense, net	(108.4)	(72.5)	(205.7)	(159.2)
Loss on extinguishment of debt		(8.2)		(8.2)
Other (expense) income, net	(17.8)	6.3	7.4	6.5
Other adjustments	(59.4)		(179)	(0.3)
(Loss) income before income taxes	(2,121.6)	42.5	(2,066.5)	284.9
Depreciation, depletion and amortization	395.8	373.6	769	740.1
Other adjustments	59.4		179	0.3
Equity in income (loss) of unconsolidated entities	4.5	20.6	(31.5)	39
Assets	28,210.4		28,210.4		$ 28,405.5
Intangibles, net	2,759.1		2,759.1		2,920.6
Equity method investments	80.5		80.5		480.4
Capital expenditures			563.7	354.1
Assets Held for Sale [Member]
Segment Reporting Information [Line Items]
Assets	169.2		169.2		34.4
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	5,368	5,470	10,365.5	10,506.1
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	(90.4)	(87.9)	(164.8)	(171.8)
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Interest expense, net	(108.4)	(72.5)	(205.7)	(159.2)
Corrugated Packaging [Member]
Segment Reporting Information [Line Items]
Net sales	2,627.4	2,319	4,964.8	4,539
Goodwill impairment	(514.3)
Depreciation, depletion and amortization	211.2	166.9	403.4	333.9
Other adjustments	4.7	(6.4)	54.5	(6.4)
Equity in income (loss) of unconsolidated entities	4	20.6	(31.8)	35.6
Assets	13,066		13,066		11,382.5
Intangibles, net	608.2		608.2		648.4
Equity method investments	78.6		78.6		479.3
Capital expenditures			241.7	156.7
Corrugated Packaging [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	2,627.4	2,319	4,964.8	4,539
Adjusted EBITDA	407.5	328.7	736.9	617.6
Corrugated Packaging [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	(81.6)	(78.5)	(150)	(152.7)
Corrugated Packaging [Member] | Unaffiliated Customers [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	2,545.8	2,240.5	4,814.8	4,386.3
Consumer Packaging [Member]
Segment Reporting Information [Line Items]
Net sales	1,265.1	1,250.6	2,480.1	2,389.3
Depreciation, depletion and amortization	85.5	90.1	169.6	176.4
Other adjustments	28	7.5	59.6	7.7
Equity in income (loss) of unconsolidated entities				3.4
Assets	6,647		6,647		6,704.5
Intangibles, net	1,460.9		1,460.9		1,523.5
Equity method investments	0.6		0.6		0.5
Capital expenditures			125.5	67.9
Consumer Packaging [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	1,265.1	1,250.6	2,480.1	2,389.3
Adjusted EBITDA	218.6	205.8	401.9	375.1
Consumer Packaging [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	(7.5)	(6.9)	(12.2)	(12.9)
Consumer Packaging [Member] | Unaffiliated Customers [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	1,257.6	1,243.7	2,467.9	2,376.4
Global Paper [Member]
Segment Reporting Information [Line Items]
Net sales	1,168.2	1,538.1	2,291.8	2,890.7
Goodwill impairment	(1,378.7)
Depreciation, depletion and amortization	91.2	109.8	180.3	216
Other adjustments	9.1	(1.1)	26.6	(1)
Equity in income (loss) of unconsolidated entities	0.5		0.3
Assets	5,151.1		5,151.1		7,039.2
Intangibles, net	563.8		563.8		612.6
Equity method investments	1.2		1.2		0.5
Capital expenditures			144.1	108.8
Global Paper [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	1,168.2	1,538.1	2,291.8	2,890.7
Adjusted EBITDA	187.1	308.6	344.4	541
Global Paper [Member] | Unaffiliated Customers [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	1,168.2	1,538.1	2,291.8	2,890.7
Distribution [Member]
Segment Reporting Information [Line Items]
Net sales	307.3	362.3	628.8	687.1
Depreciation, depletion and amortization	6.9	5.8	13.8	11.6
Assets	813.5		813.5		863
Intangibles, net	126.2		126.2		136.1
Capital expenditures			7.6	2.5
Distribution [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	307.3	362.3	628.8	687.1
Adjusted EBITDA	9.3	28	20.1	34.5
Distribution [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	(1.3)	(2.5)	(2.6)	(6.2)
Distribution [Member] | Unaffiliated Customers [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	306	359.8	626.2	680.9
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Depreciation, depletion and amortization	1	$ 1	1.9	2.2
Other adjustments	17.6		38.3
Assets	2,363.6		2,363.6		2,381.9
Equity method investments	$ 0.1		0.1		$ 0.1
Capital expenditures			$ 44.8	$ 18.2

Segment Information - Changes i

Segment Information - Changes in Carrying Amount of Goodwill (Details) $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2023 USD ($)	Mar. 31, 2023 USD ($)
Goodwill [Line Items]
Balance at beginning of period		$ 5,895.2
Goodwill impairment	$ (1,893)	(1,893)
Acquisitions		233.3
Divestitures		(11.5)
Transferred to assets held for sale		(24.9)
Translation and other adjustments		53.9
Goodwill	6,146	6,146
Accumulated impairment losses	(1,893)	(1,893)
Balance at end of period	4,253	4,253
Corrugated Packaging
Goodwill [Line Items]
Balance at beginning of period		2,802.8
Goodwill impairment		(514.3)
Acquisitions		233.3
Translation and other adjustments		71.9
Goodwill	3,108	3,108
Accumulated impairment losses	(514.3)	(514.3)
Balance at end of period	2,593.7	2,593.7
Consumer Packaging
Goodwill [Line Items]
Balance at beginning of period		1,588.4
Divestitures		(7.4)
Transferred to assets held for sale		(24.9)
Translation and other adjustments		(35.4)
Goodwill	1,520.7	1,520.7
Balance at end of period	1,520.7	1,520.7
Global Paper
Goodwill [Line Items]
Balance at beginning of period		1,366.5
Goodwill impairment		(1,378.7)
Divestitures		(4.1)
Translation and other adjustments		16.3
Goodwill	1,378.7	1,378.7
Accumulated impairment losses	(1,378.7)	(1,378.7)
Distribution
Goodwill [Line Items]
Balance at beginning of period		137.5
Translation and other adjustments		1.1
Goodwill	138.6	138.6
Balance at end of period	$ 138.6	$ 138.6

Interest Expense, Net - Summary

Interest Expense, Net - Summary of Components of Interest Expense, Net (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Interest Income (Expense), Net [Abstract]
Interest expense	$ (134.3)	$ (84.9)	$ (253.2)	$ (183.2)
Interest income	25.9	12.4	47.5	24
Interest expense, net	$ (108.4)	$ (72.5)	$ (205.7)	$ (159.2)

Interest Expense, Net - Additio

Interest Expense, Net - Additional Information (Details) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Interest Income (Expense), Net [Abstract]
Interest, net of amounts capitalized	$ 213.5	$ 176

Inventories - Schedule of Inven

Inventories - Schedule of Inventories (Details) - USD ($) $ in Millions	Mar. 31, 2023	Sep. 30, 2022
Inventories [Abstract]
Finished goods and work in process	$ 1,187.4	$ 1,102.4
Raw materials	1,234.2	1,135.9
Spare parts and supplies	568.8	529.6
Inventories at FIFO cost	2,990.4	2,767.9
LIFO reserve	(440.1)	(450.8)
Net inventories	$ 2,550.3	$ 2,317.1

Property, Plant and Equipment -

Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Millions	Mar. 31, 2023	Sep. 30, 2022
Property, plant and equipment at cost:
Property, plant and equipment, at cost	$ 21,300.8	$ 19,462.2
Less: accumulated depreciation, depletion and amortization	(10,137.8)	(9,380.8)
Property, plant and equipment, net	11,163	10,081.4
Land and Buildings [Member]
Property, plant and equipment at cost:
Property, plant and equipment, at cost	3,101.4	2,646.4
Machinery and Equipment [Member]
Property, plant and equipment at cost:
Property, plant and equipment, at cost	17,970.4	16,592.5
Forestlands [Member]
Property, plant and equipment at cost:
Property, plant and equipment, at cost	100.8	95.7
Transportation Equipment [Member]
Property, plant and equipment at cost:
Property, plant and equipment, at cost	23.3	24.2
Leasehold Improvements [Member]
Property, plant and equipment at cost:
Property, plant and equipment, at cost	$ 104.9	$ 103.4

Property, Plant and Equipment_2

Property, Plant and Equipment - Additional Information (Details) - USD ($) $ in Millions	Mar. 31, 2023	Sep. 30, 2022
Property, Plant and Equipment [Abstract]
Non-cash additions to property, plant and equipment (in accounts payable)	$ 139.5	$ 223.2

Fair Value - Additional Informa

Fair Value - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022	Sep. 30, 2022	Sep. 16, 2022	Dec. 02, 2021
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Goodwill impairment loss	$ 1,893		$ 1,893
Maximum eligible receivables that may be sold						$ 700	$ 110
Receivables sold under accounts receivable sales agreement	719.6		719.6		$ 724.7
Estimated loss on sale of accounts receivable by quarter	$ 13.3	$ 3.2	$ 24.2	$ 5.4

Fair Value - Summary of Account

Fair Value - Summary of Accounts Receivable Sales Agreement (Details) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Receivables sold to the financial institutions and derecognized	$ (1,426.9)	$ (1,454.3)
Receivables collected by financial institutions	1,432	1,410.9
Cash (payments to) proceeds from financial institutions	$ (5.1)	$ 43.4

Debt - Schedule of Carrying Val

Debt - Schedule of Carrying Value of Individual Components of Debt (Details) - USD ($) $ in Millions	Mar. 31, 2023	Sep. 30, 2022
Debt Instrument [Line Items]
Total debt	$ 9,505.6	$ 7,787.2
Less: current portion of debt	501.6	212.2
Long-term debt due after one year	9,004	7,575
Commercial Paper [Member]
Debt Instrument [Line Items]
Total debt	291.4
Notes Due Fiscal 2024 To 2028 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Total debt	3,435.6	3,433.4
Notes Due Fiscal 2029 to 2033 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Total debt	2,746.5	2,753.3
Notes Due Fiscal 2037 to 2047 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Total debt	177.5	177.8
Term Loan Facilities [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Total debt	1,597.1	598.2
Revolving Credit and Swing Facilities [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Total debt	218.1	286.3
Receivables Securitization [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Total debt	375
Finance Lease Obligations [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Total debt	410.9	287.5
Vendor Financing and Commercial Card Programs [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Total debt	128.5	123.1
International and Other Debt [Member]
Debt Instrument [Line Items]
Total debt	$ 125	$ 127.6

Debt - Additional Information (

Debt - Additional Information (Details) € in Millions

Feb. 28, 2023 USD ($)

Aug. 18, 2022 USD ($)

Jul. 07, 2022 USD ($)

Jan. 18, 2021 BRL (R$)

Dec. 07, 2018 USD ($)

Mar. 31, 2023 USD ($)

Mar. 31, 2023 EUR (€)

Mar. 31, 2023 BRL (R$)

Sep. 30, 2022 USD ($)

Sep. 30, 2022 EUR (€)

Sep. 30, 2022 BRL (R$)

Jul. 07, 2022 EUR (€)

Debt Instrument [Line Items]

Fair value of debt

$ 9,200,000,000

$ 7,300,000,000

Revolving Credit Facility [Member] | Senior Unsecured Debt [Member]

Debt Instrument [Line Items]

Credit Facility, maximum borrowing capacity

$ 2,300,000,000

Long-term debt

0

0

Debt instrument, term, in years

5 years

European Revolving Credit Facility [Member] | Senior Unsecured Debt [Member]

Debt Instrument [Line Items]

Credit Facility, maximum borrowing capacity | €

€ 700

Long-term debt

218,100,000

€ 200

265,000,000

€ 270

Debt instrument, term, in years

3 years

Incremental line of credit | €

€ 100

Farm Credit Facility [Member] | Senior Unsecured Debt [Member]

Debt Instrument [Line Items]

Credit Facility, maximum borrowing capacity

$ 600,000,000

Long-term debt

598,400,000

598,200,000

Debt instrument, term, in years

7 years

Credit facility, amount of potential increase to the principal amount

$ 400,000,000

Delayed Draw Term Facility [Member] | Senior Unsecured Debt [Member]

Debt Instrument [Line Items]

Credit Facility, maximum borrowing capacity

$ 1,000,000,000

Credit facility option to extend maturity date, year

1 year

Credit facility maturity extension cost fee

0.20%

Long-term debt

998,700,000

Debt instrument, term, in years

3 years

Receivables Securitization Facility [Member] | Secured Debt [Member]

Debt Instrument [Line Items]

Long-term debt

375,000,000

0

Receivables backed financing, maximum borrowing amount

$ 700,000,000

Debt instrument, amended maturity date

Feb. 27, 2026

Debt instrument, maximum borrowing capacity, amount

700,000,000

700,000,000

Receivables Securitization Facility [Member] | Secured Debt [Member] | Collateralizing [Member]

Debt Instrument [Line Items]

Carrying amount of accounts receivable collateralizing maximum available borrowings

1,222,100,000

1,390,500,000

Receivables Securitization Facility [Member] | Secured Debt [Member] | SOFR Loans [Member]

Debt Instrument [Line Items]

Variable rate basis

On February 28, 2023, we amended our existing $700.0 million receivables securitization agreement (the “Receivables Securitization Facility”), primarily to extend the maturity to February 27, 2026 and to complete the transition from LIBOR to Term SOFR. Term SOFR loans will be subject to a credit spread adjustment equal to 0.10% per annum. No other changes were made to the rates in the agreement. The used borrowing rate spread above base remains at 0.90%, and the unused rate remains at 0.25% or 0.35%, dependent on whether the amount borrowed is above or below 50% of the maximum borrowing limit

Credit spread adjustment

0.10%

Applicable margin

0.90%

Receivables Securitization Facility [Member] | Secured Debt [Member] | SOFR Loans [Member] | Maximum [Member]

Debt Instrument [Line Items]

Borrowing limit percentage

50%

Brazil Export Credit Note [Member] | Senior Unsecured Debt [Member]

Debt Instrument [Line Items]

Credit Facility, maximum borrowing capacity | R$

R$ 500000000.0

Long-term debt

83,600,000

R$ 428600000

92,700,000

R$ 500000000.0

Credit facility semiannual installments repayment beginning date

Jan. 19, 2023

Credit facility, maturity date

Jan. 19, 2026

Credit facility basis spread on floating rate

2.50%

Commercial Paper [Member] | Senior Unsecured Short Term Debt [Member]

Debt Instrument [Line Items]

Aggregate Principal Amount of Short-term Unsecured Commercial Paper Program, Maximum

$ 1,000,000,000

Debt Instrument, notice period for termination

30 days

Debt instrument, issued amount

$ 291,400,000

Borrowings outstanding

$ 0

Commercial Paper [Member] | Senior Unsecured Short Term Debt [Member] | Maximum [Member]

Debt Instrument [Line Items]

Debt instrument, maturity period

397 days

U.S. Revolving Facility [Member] | Senior Unsecured Debt [Member]

Debt Instrument [Line Items]

Credit Facility, maximum borrowing capacity

1,800,000,000

Multicurrency Revolving Facility [Member] | Senior Unsecured Debt [Member]

Debt Instrument [Line Items]

Credit Facility, maximum borrowing capacity

$ 500,000,000

Above borrowing limit [Member] | Receivables Securitization Facility [Member] | Secured Debt [Member] | SOFR Loans [Member]

Debt Instrument [Line Items]

Unused borrowing rate

0.25%

Below borrowing limit [Member] | Receivables Securitization Facility [Member] | Secured Debt [Member] | SOFR Loans [Member]

Debt Instrument [Line Items]

Unused borrowing rate

0.35%

Leases - Additional Information

Leases - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Leases [Abstract]
Total lease cost, net	$ 99.3	$ 87.1	$ 196.6	$ 169.8
ROU asset obtained in exchange for operating lease liability			$ 69.8	$ 63.4

Leases - Summary of Supplementa

Leases - Summary of Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Millions	Mar. 31, 2023	Sep. 30, 2022
Supplementary Information Balance Sheets [Abstract]
Operating lease right-of-use asset	$ 657.3	$ 699.6
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Other noncurrent assets	Other noncurrent assets
Current operating lease liabilities	$ 198.6	$ 191.9
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other current liabilities	Other current liabilities
Noncurrent operating lease liabilities	$ 505.7	$ 551.1
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other noncurrent liabilities	Other noncurrent liabilities
Total operating lease liabilities	$ 704.3	$ 743
Property, plant and equipment	314.8	177.4
Accumulated depreciation	(49.5)	(37.3)
Property, plant and equipment, net	265.3	140.1
Current finance lease liabilities	$ 22.3	$ 14.5
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Current portion of debt	Current portion of debt
Noncurrent finance lease liabilities	$ 388.6	$ 273
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Long-term debt due after one year	Long-term debt due after one year
Total finance lease liabilities	$ 410.9	$ 287.5

Derivatives - Additional Inform

Derivatives - Additional Information (Details)	6 Months Ended
	Mar. 31, 2023
Natural Gas Commodity Hedge [Member] | Maximum [Member]
Derivative [Line Items]
Derivative hedging volume period	12 months

Derivatives - Summary Of Outsta

Derivatives - Summary Of Outstanding Notional Amounts (Details) BTU in Millions, $ in Millions		6 Months Ended	12 Months Ended
		Mar. 31, 2023 BTU	Sep. 30, 2022 MXN ($) BTU
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Natural Gas Commodity Hedge [Member]
Derivative [Line Items]
Notional amount of natural gas derivatives | BTU		21.3	18.3
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivative [Line Items]
Outstanding notional amounts | $	[1]		8,000
[1] At September 30, 2022, the outstanding foreign currency exchange contract was related to the purchase of 8.0 billion Mexican pesos ($ 389.9 million) for refinancing Grupo Gondi's external debt upon the Grupo Gondi Acquisition on December 1, 2022 .

Derivatives - Summary Of Outs_2

Derivatives - Summary Of Outstanding Notional Amounts (Parenthetical) (Details) $ in Millions, $ in Billions	Dec. 01, 2022	Sep. 30, 2022 MXN ($)	Sep. 30, 2022 USD ($)
Grupo Gondi [Member]
Derivative [Line Items]
Date of acquisition	Dec. 01, 2022
Foreign Exchange Contract [Member]
Derivative [Line Items]
Derivative notional amount		$ 8	$ 389.9

Derivatives - Summary of Locati

Derivatives - Summary of Location and Fair Values of Derivative Instruments (Details) - USD ($) $ in Millions		Mar. 31, 2023	Sep. 30, 2022
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Natural Gas Commodity Hedge [Member]
Derivative [Line Items]
Derivative Liability	[1]	$ 32.3	$ 12
Derivative Liability, Statement of Financial Position [Extensible Enumeration]		Other Liabilities, Current	Other Liabilities, Current
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivative [Line Items]
Derivative Asset			$ 3.4
Derivative Asset, Statement of Financial Position [Extensible Enumeration]			Other Assets, Current
[1] At September 30, 2022, liability positions by counterparty were partially offset by $ 2.3 million of asset positions where we had an enforceable right of netting.

Derivatives - Summary of Loca_2

Derivatives - Summary of Location and Fair Values of Derivative Instruments (Parenthetical) (Details) $ in Millions	Sep. 30, 2022 USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Asset positions offset with liability positions	$ 2.3

Derivatives - Summary of Gains

Derivatives - Summary of Gains (Losses) Recognized in Accumulated Other Comprehensive Loss, Net of Tax for Cash Flow Hedges (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2023	Mar. 31, 2023
Derivative [Line Items]
Gains (losses) recognized in accumulated other comprehensive loss, net of tax for cash flow hedges	$ (20.1)	$ (30)
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Natural Gas Commodity Hedge [Member]
Derivative [Line Items]
Gains (losses) recognized in accumulated other comprehensive loss, net of tax for cash flow hedges	$ (3.4)	$ (15.3)

Derivatives - Summary of Gain_2

Derivatives - Summary of Gains (Losses) Recognized in the Statements of Income (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2023	Mar. 31, 2023
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Natural Gas Commodity Hedge [Member]
Derivative [Line Items]
Gains (losses) recognized in the statements of income for cash flow hedges reclassified from accumulated other comprehensive loss	$ (26.8)	$ (40)
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Cost of Goods and Services Sold	Cost of Goods and Services Sold
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Other (expense) income, net
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		$ 19.7

Special Purpose Entities - Sche

Special Purpose Entities - Schedule of Restricted Assets and Non-recourse Liabilities Held by Special Purposes Entities (Details) - Rock-Tenn Company and MeadWestvaco Corporation's [Member] - Installment Note [Member] - USD ($) $ in Millions	Mar. 31, 2023	Sep. 30, 2022
Debt Instrument [Line Items]
Other current assets	$ 867.9
Other noncurrent assets	381.1	$ 1,253
Other current liabilities	782.5
Other noncurrent liabilities	$ 330.2	$ 1,117.8

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) R$ in Millions	6 Months Ended
	Mar. 31, 2023 USD ($) Lawsuit Subsidiary	Mar. 31, 2023 BRL (R$) Subsidiary	Apr. 30, 2020 USD ($)	Feb. 29, 2020 USD ($)
Commitments and Contingencies [Line Items]
Accrual for Environmental Loss Contingencies	$ 7,700,000
Guarantor Obligations, Current Carrying Value	800,000
Maximum [Member]
Commitments and Contingencies [Line Items]
Guarantor Obligations, Estimated Exposure, Undiscounted	$ 50,000,000
Brazil Administrative Council of Tax Appeals [Member]
Commitments and Contingencies [Line Items]
Tax claim and conversion description	The matter has proceeded through the Brazil Administrative Council of Tax Appeals (“CARF”) principally in two proceedings, covering tax years 2003 to 2008 and 2009 to 2012.	The matter has proceeded through the Brazil Administrative Council of Tax Appeals (“CARF”) principally in two proceedings, covering tax years 2003 to 2008 and 2009 to 2012.
Income tax settlement claim liability	$ 0
Tax claim and conversion, tax dispute related to tax years description	2009 to 2012	2009 to 2012
Claimed tax deficiency including penalties and interest	$ 136,000,000	R$ 695
Brazil [Member]
Commitments and Contingencies [Line Items]
Number of subsidiaries | Subsidiary	2	2
Pace Industry Union Management Pension Fund [Member]
Commitments and Contingencies [Line Items]
Withdrawal obligation accumulated funding deficiency				$ 51,200,000
Pace Industry Union Management Pension Fund [Member] | Subsidiary [Member]
Commitments and Contingencies [Line Items]
Withdrawal obligation accumulated funding deficiency			$ 1,300,000
Asbestos Litigation [Member]
Commitments and Contingencies [Line Items]
Number of Lawsuits the Company Has Been Named a Defendant in Asbestos-related Personal Injury Litigation | Lawsuit	700
Amount reserved for litigation	$ 12,200,000
Other Noncurrent Liabilities [Member]
Commitments and Contingencies [Line Items]
Accrual for Environmental Loss Contingencies	1,400,000
Other Current Liabilities [Member]
Commitments and Contingencies [Line Items]
Accrual for Environmental Loss Contingencies	$ 6,300,000

Equity and Other Comprehensiv_3

Equity and Other Comprehensive Income (Loss) - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Sep. 30, 2022	May 04, 2022	Jul. 31, 2015
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Stock repurchase program, number of shares authorized to be repurchased				25,000,000	40,000,000
Common Stock, Par or Stated Value Per Share	$ 0.01		$ 0.01		$ 0.01
Authorized share repurchase as a percentage of common stock outstanding				10%	15%
Stock repurchase program, remaining number of shares authorized to be repurchased	29,000,000
Treasury stock, shares, acquired	0	7,200,000
Purchases of common stock		$ 332.1
Minimum [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Effective Tax Rate, Net of Tax Components of Other Comprehensive Income	26%	25%
Maximum [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Effective Tax Rate, Net of Tax Components of Other Comprehensive Income	27%	26%

Equity and Other Comprehensiv_4

Equity and Other Comprehensive Income (Loss) - Schedule of Changes in Accumulated Other Comprehensive Loss, Net of Tax (Details) - USD ($) $ in Millions		6 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	[1]	$ (1,454.3)	$ (999.1)
Other comprehensive (loss) income before reclassifications	[1]	254.4	113.5
Amounts reclassified from accumulated other comprehensive loss	[1]	81.4	5.4
Net current period other comprehensive (loss) income	[1]	335.8	118.9
Balance at end of period	[1]	(1,118.5)	(880.2)
Accumulated Net Gain (Loss) from Designated or Quality Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period		(9.1)	(0.2)
Other comprehensive (loss) income before reclassifications		(45.3)
Amounts reclassified from accumulated other comprehensive loss		30
Net current period other comprehensive (loss) income		(15.3)
Balance at end of period		(24.4)	(0.2)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period		(741.6)	(536.5)
Other comprehensive (loss) income before reclassifications			0.1
Amounts reclassified from accumulated other comprehensive loss		22.4	5.4
Net current period other comprehensive (loss) income		22.4	5.5
Balance at end of period		(719.2)	(531)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period		(703.6)	(462.4)
Other comprehensive (loss) income before reclassifications		299.7	113.4
Amounts reclassified from accumulated other comprehensive loss		29
Net current period other comprehensive (loss) income		328.7	113.4
Balance at end of period		$ (374.9)	$ (349)
[1] All amounts are net of tax and noncontrolling interests.

Equity and Other Comprehensiv_5

Equity and Other Comprehensive Income (Loss) - Summary of Reclassification out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions		3 Months Ended				6 Months Ended
		Mar. 31, 2023		Mar. 31, 2022		Mar. 31, 2023		Mar. 31, 2022
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Amortization of actuarial losses, Net of Tax		$ 10.1		$ 1.5		$ 19.8		$ 2.8
Amortization of prior service costs, Net of Tax		1.4		1.5		2.8		2.9
Recognition of previously unrealized foreign currency losses on consolidation of equity investment, Net of Tax						29
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax		20.1				30
Parent [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Amortization of actuarial losses, Pre-tax		(13.2)	[1],[2]	(1.9)	[1],[2]	(26.5)	[3],[4]	(3.5)	[3],[4]
Amortization of actuarial losses, Tax		3.3	[1],[2]	0.5	[1],[2]	6.9	[3],[4]	0.9	[3],[4]
Amortization of actuarial losses, Net of Tax		(9.9)	[1],[2]	(1.4)	[1],[2]	(19.6)	[3],[4]	(2.6)	[3],[4]
Amortization of prior service costs, Pre-Tax Amount		(1.9)	[1],[2]	(1.9)	[1],[2]	(3.8)	[3],[4]	(3.8)	[3],[4]
Amortization of prior service costs, Tax		0.5	[1],[2]	0.5	[1],[2]	1	[3],[4]	1	[3],[4]
Amortization of prior service costs, Net of Tax		(1.4)	[1],[2]	(1.4)	[1],[2]	(2.8)	[3],[4]	(2.8)	[3],[4]
Defined Benefit Plans, before Tax		(15.1)	[1]	(3.8)	[1]	(30.3)	[3]	(7.3)	[3]
Defined Benefit Plans, Tax		3.8	[1]	1	[1]	7.9	[3]	1.9	[3]
Defined Benefit Plans, Net of Tax		(11.3)	[1]	(2.8)	[1]	(22.4)	[3]	(5.4)	[3]
Recognition of previously unrealized foreign currency losses on consolidation of equity investment, Pre-tax	[3],[5]					(29)
Recognition of previously unrealized foreign currency losses on consolidation of equity investment, Net of Tax	[3],[5]					(29)
Total Reclassifications From Other Comprehensive Income Before Tax		(41.9)	[1]	(3.8)	[1]	(99.3)	[3]	(7.3)	[3]
Total Reclassifications From Other Comprehensive Income Tax Portion		10.5	[1]	1	[1]	17.9	[3]	1.9	[3]
Total Reclassifications From Other Comprehensive Income Net of Tax		(31.4)	[1]	$ (2.8)	[1]	(81.4)	[3]	$ (5.4)	[3]
Parent [Member] | Natural Gas Commodity Hedge [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax		(26.8)	[1],[6]			(40)	[3],[7]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax		6.7	[1],[6]			10	[3],[7]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax		$ (20.1)	[1],[6]			$ (30)	[3],[7]
[1] Amounts in parentheses indicate charges to earnings. Amounts pertaining to noncontrolling interests are excluded. Included in the computation of net periodic pension cost. See “ Note 6. Retirement Plans ” for additional details. Amounts in parentheses indicate charges to earnings. Amounts pertaining to noncontrolling interests are excluded. Included in the computation of net periodic pension cost. See “ Note 6. Retirement Plans ” for additional details. Amount reflected in Equity in income (loss) of unconsolidated entities in the consolidated statements of operations. These accumulated other comprehensive loss components are included in Cost of goods sold. These accumulated other comprehensive loss components are included in Cost of goods sold.

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Earnings Per Share [Abstract]
Net (loss) income attributable to common stockholders	$ (2,006.1)	$ 39.9	$ (1,960.8)	$ 222.2
Less: Distributed and undistributed income available to participating securities, Basic		(0.1)		(0.1)
Distributed and undistributed (loss) income available to common stockholders, Basic	(2,006.1)	39.8	(1,960.8)	222.1
Less: Distributed and undistributed income available to participating securities, Diluted		(0.1)		(0.1)
Distributed and undistributed (loss) income available to common stockholders, Diluted	$ (2,006.1)	$ 39.8	$ (1,960.8)	$ 222.1
Basic weighted average shares outstanding	255.6	263.4	255.2	264
Effect of dilutive stock options and non- participating securities		1.9		2.1
Diluted weighted average shares outstanding	255.6	265.3	255.2	266.1
Basic (loss) earnings per share attributable to common stockholders	$ (7.85)	$ 0.15	$ (7.68)	$ 0.84
Diluted (loss) earnings per share attributable to common stockholders	$ (7.85)	$ 0.15	$ (7.68)	$ 0.83

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Details) - shares shares in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Earnings Per Share [Abstract]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	2.5	0.4	2.8	0.4