98.4

Dividends declared (per share - $0.24, $0.465, $0.64 and $1.13)

465.1

^[3]

(295.4)

$ (244.8)

^[4]

(244.8)

Total Stockholders' equity at Jun. 30, 2020

(3.3)

2.5

^[1]

11,713.1

259.5

Beginning balance at Mar. 31, 2020

11,729.9

$ 2.6

10,857.6

2,240.3

(1,387.4)

16.8

^[1]

259.2

Beginning balance at Mar. 31, 2020

$ 2.6

10,784.4

2,114.4

(1,419.0)

15.6

^[1]

Issuance of common stock, net of stock received for tax withholdings

0.3

Issuance of common stock, net of stock received for tax withholdings

4.3

68.9

Dividends declared (per share - $0.24, $0.465, $0.64 and $1.13)

178.5

^[3]

(52.6)

31.6

Total Stockholders' equity at Jun. 30, 2020

(1.5)

1.2

^[1]

11,713.1

259.5

Beginning balance at Sep. 30, 2020

$ 11,729.9

$ 2.6

10,857.6

2,240.3

(1,387.4)

16.8

^[1]

260.4

Total Stockholders' equity at Sep. 30, 2020

$ 10,630.6

Beginning balance at Sep. 30, 2020

10,647.5

$ 2.6

10,916.3

1,031.6

(1,319.9)

16.9

^[1]

Adoption of accounting standards

^[2]

$ (3.8)

Issuance of common stock, net of stock received for tax withholdings

6.5

Issuance of common stock, net of stock received for tax withholdings

$ 0.1

128.9

(0.5)

74.3

Other

(1.1)

Dividends declared (per share - $0.24, $0.465, $0.64 and $1.13)

514.6

^[3]

(171.1)

279.1

^[4]

279.1

Distributions and adjustments to noncontrolling interests

(3.3)

1.4

^[1]

^[1]

1.1

Total Stockholders' equity at Jun. 30, 2021

$ 11,451.1

266.9

Beginning balance at Mar. 31, 2021

$ 11,470.5

$ 2.7

11,118.4

1,370.8

(1,040.8)

19.4

^[1]

265.9

Beginning balance at Mar. 31, 2021

$ 2.7

11,057.5

1,186.0

(1,194.3)

18.1

^[1]

Issuance of common stock, net of stock received for tax withholdings

1.0

Issuance of common stock, net of stock received for tax withholdings

38.6

(0.3)

23.4

Other

(1.1)

Dividends declared (per share - $0.24, $0.465, $0.64 and $1.13)

250.1

^[3]

(65.0)

153.5

Distributions and adjustments to noncontrolling interests

(0.9)

0.2

^[1]

^[1]

1.1

Total Stockholders' equity at Jun. 30, 2021

$ 11,451.1

266.9

Basis of Presentation and Significant Accounting Policies

$ 11,470.5

$ 2.7

$ 11,118.4

$ 1,370.8

$ (1,040.8)

$ 19.4

^[1]

[1]	Excludes amounts related to contingently redeemable noncontrolling interests, which are separately classified outside of permanent equity on the Condensed Consolidated Balance Sheets.
[2]	For fiscal 2021, the amount relates to the adoption of ASU 2016-13 (as hereinafter defined). For fiscal 2020, the amount relates primarily to the adoption of ASU 2018-02, “Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income”.
[3]	Includes cash dividends paid and dividend equivalent units on certain restricted stock awards.
[4]	All amounts are net of tax and noncontrolling interests.

CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement Of Stockholders Equity [Abstract]
Cash dividends paid per share	$ 0.24	$ 0.465	$ 0.64	$ 1.13

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Operating activities:
Consolidated net income	$ 517.9	$ 468.4
Adjustments to reconcile consolidated net income to net cash provided by operating activities:
Depreciation, depletion and amortization	1,094.9	1,121.4
Cost of real estate sold		16.1
Deferred income tax (benefit) expense	(53.6)	16.1
Share-based compensation expense	74.4	98.4
401(k) match and company contribution in common stock	112.8
Pension and other postretirement funding more than expense (income)	(82.6)	(60.7)
Gain on sale of sawmill	(16.5)
Gain on sale of investment	(16.0)
Multiemployer pension withdrawal income		(1.1)
Other impairment adjustments	22.6	2.2
Loss (gain) on disposal of plant and equipment and other, net	3.8	(5.5)
Other, net	(73.9)	(33.4)
Change in operating assets and liabilities, net of acquisitions and divestitures:
Accounts receivable	(333.4)	82.4
Inventories	(130.8)	(70.7)
Other assets	(149.7)	(98.3)
Accounts payable	197.2	(240.1)
Income taxes	70.0	15.7
Accrued liabilities and other	365.3	28.1
Net cash provided by operating activities	1,602.4	1,339.0
Investing activities:
Capital expenditures	(505.4)	(860.2)
Investment in unconsolidated entities	(0.1)	(1.0)
Proceeds from sale of sawmill	58.5
Proceeds from sale of investment	29.5
Proceeds from sale of property, plant and equipment	4.3	22.5
Proceeds from property, plant and equipment insurance settlement	1.7	2.4
Other, net	26.0	10.9
Net cash used for investing activities	(385.5)	(825.4)
Financing activities:
Proceeds from issuance of notes		598.6
Additions to revolving credit facilities	435.0	413.0
Repayments of revolving credit facilities	(355.0)	(478.2)
Additions to debt	258.1	683.1
Repayments of debt	(1,131.5)	(1,195.8)
Repayments of commercial paper, net		(9.3)
Other debt additions (repayments), net	16.3	(69.2)
Issuances of common stock, net of related tax withholdings	14.7	16.7
Cash dividends paid to stockholders	(169.8)	(292.6)
Cash distributions paid to noncontrolling interests	(1.4)	(1.4)
Other, net	(7.7)	(17.0)
Net cash used for financing activities	(941.3)	(352.1)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	23.1	(21.6)
Increase in cash, cash equivalents and restricted cash	298.7	139.9
Cash, cash equivalents and restricted cash at beginning of period	251.1	151.6
Cash, cash equivalents and restricted cash at end of period	549.8	291.5
Supplemental disclosure of cash flow information:
Income taxes, net of refunds	140.6	90.9
Interest, net of amounts capitalized	$ 212.8	$ 251.4

Basis of Presentation and Significant Accounting Policies

9 Months Ended

Jun. 30, 2021

Accounting Policies [Abstract]

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 condensed consolidated balance sheet at September 30, 2020 from the audited consolidated financial statements included in our Annual Report on Form 10-K for the fiscal year ended September 30, 2020 (the “Fiscal 2020 Form 10-K”). In the opinion of management, all normal recurring adjustments necessary for the fair presentation of the condensed consolidated financial statements have been included for the interim periods reported.

We have condensed or omitted 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 2020 Form 10-K. The results for the three and nine months ended June 30, 2021 are not necessarily indicative of results that may be expected for the full year.

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-19”) continues to evolve. The pandemic has affected our operational and financial performance and the extent of its effect on our operational and financial performance will continue to depend on future developments, which are highly uncertain and cannot be predicted with confidence, including the duration, scope and severity of the pandemic (including due to new variants such as Delta), the actions taken to contain or mitigate its impact (including the distribution and effectiveness of vaccines), and the direct and indirect economic effects of the pandemic and related containment measures and government responses, among others.

At June 30, 2021, we evaluated the then current economic environment, including our assessment of the impact of COVID-19, as well as the ransomware incident discussed below, and there were no indicators of impairment of our long-lived assets, including goodwill, that required a quantitative test to be performed. Our estimates involve numerous assumptions about the future growth and potential volatility in revenues and costs, capital expenditures, industry and global economic factors, interest rate environment and future business strategy. Accordingly, our accounting estimates may materially change from period to period due to changing market factors, including those driven by COVID-19. We will continue to monitor future events, changes in circumstances and the potential impact thereof, including performing our annual goodwill impairment assessment in the fourth quarter of fiscal 2021. If actual results are not consistent with our assumptions and estimates, we may be exposed to impairment losses that could be material. See “Note 1. Description of Business and Summary of Significant Accounting Policies — Goodwill and Long-Lived Assets” in the Fiscal 2020 Form 10-K for additional information regarding the results of, and our methods and assumptions applied to perform, our goodwill impairment testing in fiscal 2020.

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, including shutting down certain systems out of an abundance of caution, as well as taking steps to supplement existing security monitoring, scanning and protective measures. We notified law enforcement and contacted our customers to apprise them of the situation.

We undertook extensive efforts to identify, contain and recover from this incident quickly and securely. Our teams worked to maintain our business operations and minimize the impact on our customers and teammates. All systems are back in service. All of our mills and converting locations began producing and shipping paper and packaging at pre-ransomware levels in March 2021 or earlier. Our mill system production was approximately 115,000 tons lower than planned for the quarter ended March 31, 2021 as a result of this incident. While shipments from some of our facilities initially lagged behind production levels, this gap closed as systems were restored during the second quarter of fiscal 2021. In locations where technology issues were identified, we used alternative methods, in many cases manual methods, to process and ship orders. We systematically brought our information systems back online in a controlled, phased approach.

We estimate the segment income impact of the lost sales and operational disruption of this incident on our operations in the second quarter of fiscal 2021 was approximately $50 million, as well as approximately $20 million of ransomware recovery costs, primarily professional fees. In addition, we incurred approximately $9 million of ransomware recovery costs in the third quarter of fiscal 2021. We expect to recover substantially all of the ransomware losses from cyber and business interruption insurance in future periods. Disputes over the extent of insurance coverage for claims are not uncommon, and there will be a time lag between the initial incurrence of costs and the receipt of any insurance proceeds.

In response to the ransomware event, we accelerated information technology investments that we had previously planned to make in future periods in order to further strengthen our information security infrastructure. We engaged a leading cybersecurity defense firm that completed a forensics investigation of the ransomware incident and we are taking appropriate actions in response to the findings. For example, in the short-term, we reset all credentials Company-wide and strengthened security tooling across our servers and workstations. Longer term, in collaboration with our strategic partners, we established a roadmap to advance the maturity and effectiveness of our information security and resiliency capabilities. This roadmap includes initiatives to further strengthen our information security posture across the Company, and to enable us to potentially detect, respond to and recover from security and technical incidents in a faster and more effective manner. More specifically, we are progressing projects to bolster our security monitoring capabilities, strengthen our access controls, reduce risks associated with third-parties, and to enhance the information security of our mills and plants.

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 2020 Form 10-K for a summary of our significant accounting policies.

Recent Accounting Developments

New Accounting Standards — Recently Adopted

In November 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2018-18 “Collaborative Arrangements (Topic 808): Clarifying the Interaction Between Topic 808 and Topic 606”, which provides targeted amendments to Accounting Standards Codification (“ASC”) 808, “Collaborative arrangements” and ASC 606, “Revenues from Contracts with Customers” (“ASC 606”). The amendments in this ASU require transactions between participants in a collaborative arrangement to be accounted for under ASC 606 only when the counterparty is a customer. We adopted the provisions of ASU 2018-18 on October 1, 2020. The adoption did not have a material impact on our consolidated financial statements.

In October 2018, the FASB issued ASU 2018-17 “Consolidation: Targeted Improvements to Related Party Guidance for Variable Interest Entities”. This ASU changes how entities evaluate decision-making fees under the

variable interest entity guidance. To determine whether decision-making fees represent a variable interest, an entity considers indirect interests held through related parties under common control on a proportionate basis, rather than in their entirety, as currently required under generally accepted accounting principles in the U.S. (“GAAP”). We adopted the provisions of ASU 2018-17 on October 1, 2020. The adoption did not have a material impact on our consolidated financial statements.

In August 2018, the FASB issued ASU 2018-15 “Intangibles – Goodwill and Other – Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract”. The amendments in this ASU align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). The accounting for the service element of a hosting arrangement that is a service contract is not affected by these amendments. We adopted the provisions of ASU 2018-15 prospectively on October 1, 2020. The adoption did not have a material impact on our consolidated financial statements.

In August 2018, the FASB issued ASU 2018-14 “Compensation – Retirement Benefits – Defined Benefit Plans – General (Subtopic 715-20): Changes to the Disclosure Requirements for Defined Benefit Plans”. The amendments in this ASU modify the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans to remove disclosures that no longer are considered cost beneficial, clarify the specific requirements of disclosures and add disclosure requirements identified as relevant. We adopted the provisions of ASU 2018-14 retrospectively on October 1, 2020.

In June 2016, the FASB issued ASU 2016-13 “Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments (Topic 326)” (“ASU 2016-13”), which modifies the measurement of expected credit losses of certain financial instruments and replaces the incurred loss model with a model that reflects expected credit losses. In April 2019, the FASB issued ASU 2019-04 “Codification Improvements to Topic 326, Financial Instruments – Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments” (“ASU 2019-04”), which addresses issues related to accrued interest receivable balances, recoveries, variable interest rates and prepayments, among other things. In May 2019, the FASB issued ASU 2019-05 “Financial Instruments – Credit Losses (Topic 326): Targeted Transition Relief” (“ASU 2019-05”), which provides targeted transition relief allowing entities to make an irrevocable one-time election upon adoption of the new credit losses standard to measure financial assets previously measured at amortized cost (except held-to-maturity securities) using the fair value option. In November 2019, the FASB issued ASU 2019-11 “Codification Improvements to Topic 326, Financial Instruments – Credit Losses” (“ASU 2019-11”), which makes certain narrow-scope amendments to Topic 326, including allowing entities to exclude accrued interest amounts from various required disclosures under Topic 326. In February 2020, the FASB issued ASU 2020-02 “Financial Instruments – Credit Losses (Topic 326) and Leases (Topic 842)” (“ASU 2020-02”), which adds and amends paragraphs in the ASC to reflect the issuance of SEC Staff Accounting Bulletin No. 119 primarily related to the new credit losses standard. The provisions of ASU 2019-04, ASU 2019-05, ASU 2019-11 and ASU 2020-02 related to Topic 326 are effective concurrent with the adoption of ASU 2016-13. We adopted ASU 2016-13 and its subsequent revisions using the modified retrospective transition approach on October 1, 2020. The adoption of ASU 2016-13 and its subsequent revisions resulted in us recognizing a cumulative effect adjustment of $3.8 million (net of tax) decrease to opening balance of retained earnings related to our allowance for doubtful accounts primarily for our trade accounts receivable balance.

New Accounting Standards — Recently Issued

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 the London Interbank Offered Rate (“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 can be adopted after their respective issuance dates through December 31, 2022. We are evaluating the impact of these ASUs.

In December 2019, the FASB issued ASU 2019-12 “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes”. This ASU simplifies the accounting for income taxes by removing certain exceptions to the

general principles in Topic 740 under GAAP. This ASU also improves consistent application of and simplifies GAAP for other areas of Topic 740 by clarifying and amending existing guidance. This ASU is effective for fiscal years beginning after December 15, 2020 (fiscal 2022 for us) and interim periods within those fiscal years. Early adoption is permitted. While we are still finalizing our evaluation of the impact of this ASU, we do not expect the adoption of this ASU to have a material impact on our consolidated financial statements.

Revenue Recognition

9 Months Ended

Jun. 30, 2021

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. In fiscal 2020, we completed our real estate monetization; therefore, we will not have any Land and Development sales in fiscal 2021.

	Three Months Ended June 30, 2021
(In millions)	Corrugated Packaging		Consumer Packaging		Intersegment Sales			Total

Primary Geographical Markets
North America	$	3,020.9	$	1,353.9	$	(85.1	)	$	4,289.7
South America		127.2		17.7		—			144.9
Europe		1.5		285.6		(0.1	)		287.0
Asia Pacific		17.5		77.5		(0.3	)		94.7
Total	$	3,167.1	$	1,734.7	$	(85.5	)	$	4,816.3

	Nine Months Ended June 30, 2021
(In millions)	Corrugated Packaging		Consumer Packaging		Intersegment Sales			Total

Primary Geographical Markets
North America	$	8,588.2	$	3,839.6	$	(208.3	)	$	12,219.5
South America		304.7		63.0		—			367.7
Europe		3.5		800.8		(0.2	)		804.1
Asia Pacific		48.6		216.3		(0.6	)		264.3
Total	$	8,945.0	$	4,919.7	$	(209.1	)	$	13,655.6

	Three Months Ended June 30, 2020
(In millions)	Corrugated Packaging		Consumer Packaging		Land and Development		Intersegment Sales			Total

Primary Geographical Markets
North America	$	2,632.4	$	1,238.4	$	—	$	(44.8	)	$	3,826.0
South America		87.8		14.1		—		—			101.9
Europe		0.6		233.8		—		(0.2	)		234.2
Asia Pacific		8.0		66.3		—		(0.1	)		74.2
Total	$	2,728.8	$	1,552.6	$	—	$	(45.1	)	$	4,236.3

	Nine Months Ended June 30, 2020
(In millions)	Corrugated Packaging		Consumer Packaging		Land and Development		Intersegment Sales			Total

Primary Geographical Markets
North America	$	8,187.0	$	3,718.8	$	18.9	$	(137.7	)	$	11,787.0
South America		296.1		52.9		—		—			349.0
Europe		4.9		731.8		—		(0.2	)		736.5
Asia Pacific		32.8		202.3		—		(0.3	)		234.8
Total	$	8,520.8	$	4,705.8	$	18.9	$	(138.2	)	$	13,107.3

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 condensed consolidated balance sheet.

(In millions)	Contract Assets (Short-Term)		Contract Liabilities (Short-Term)

Beginning balance - October 1, 2020	$	185.8	$	12.0
Ending balance - June 30, 2021		193.9		22.7
Increase	$	8.1	$	10.7

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-URI http://asc.fasb.org/topic&trid=49130388

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130551-203045

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130556-203045

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (b)
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (a)
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 12
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130558-203045

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130554-203045

Restructuring And Other Costs [Abstract]

Restructuring and Other Costs

9 Months Ended

Jun. 30, 2021

Restructuring and Other Costs

Note 3.

Restructuring and Other Costs

Summary of Restructuring and Other Initiatives

We recorded pre-tax restructuring and other costs of $6.9 and $19.8 million for the three and nine months ended June 30, 2021 and $9.7 and $56.2 million for the three and nine months ended June 30, 2020. 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					Nine Months Ended
	June 30,					June 30,
	2021			2020		2021		2020
Restructuring	$	7.0		$	7.4	$	17.7	$	40.1
Other		(0.1	)		2.3		2.1		16.1
Restructuring and other costs	$	6.9		$	9.7	$	19.8	$	56.2

Restructuring

Our restructuring charges are primarily associated with restructuring portions of our operations (i.e. partial or complete plant closures), employee costs due to merger and acquisition-related workforce reductions and voluntary retirement programs in fiscal 2019 and 2020. A partial plant closure may consist of shutting down a machine and/or a workforce reduction.

When we close a facility, if necessary, we recognize a write-down to reduce the carrying value of related property, plant and equipment and lease right-of-use assets (“ROU”) to their fair value and record charges for severance and other employee-related costs. We reduce the carrying value of the assets classified as held for sale to their estimated fair value less cost to sell. Any subsequent change in fair value less cost to sell prior to disposition is recognized as it is identified; however, no gain is recognized in excess of the cumulative loss previously recorded unless the actual selling price exceeds the original carrying value. For plant closures, we also generally expect to record costs for equipment relocation, facility carrying costs and costs to terminate a lease or contract before the end of its term.

Although specific circumstances vary, our strategy has generally been to consolidate our sales and operations into large well-equipped plants that operate at high utilization rates and take advantage of available capacity created by operational excellence initiatives and/or further optimize our system following mergers and acquisitions or a changing business environment. Therefore, we generally transfer a substantial portion of each closed plant’s assets and production to our other plants. We believe these actions have allowed us to more effectively manage our business. In our former Land and Development segment, the restructuring charges primarily consisted of severance and other employee costs associated with the wind-down of operations and lease costs.

While restructuring costs are not charged to our segments and, therefore, do not reduce segment income, we highlight the segment to which the charges relate. The following table presents a summary of restructuring charges related to active restructuring initiatives that we incurred during the three and nine months ended June 30, 2021 and 2020, the cumulative recorded amount since we started the initiatives and our estimate of the total we expect to incur (in millions):

	Three Months Ended						Nine Months Ended
	June 30,						June 30,
	2021			2020			2021			2020		Cumulative		Total Expected
Corrugated Packaging

Net property, plant and equipment costs	$	—		$	(0.3	)	$	—		$	2.2	$	94.4	$	94.4
Severance and other employee costs		0.3			3.2			(0.8	)		6.8		51.6		51.6
Equipment and inventory relocation costs		0.7			0.2			0.7			1.5		9.4		9.4
Facility carrying costs		0.3			0.4			1.3			1.4		22.2		23.8
Other costs		(0.1	)		0.1			0.4			0.5		3.9		3.9
Restructuring total	$	1.2		$	3.6		$	1.6		$	12.4	$	181.5	$	183.1

Consumer Packaging

Net property, plant and equipment costs	$	—		$	—		$	0.2		$	0.5	$	35.4	$	35.4
Severance and other employee costs		4.2			1.9			10.1			15.0		47.5		47.5
Equipment and inventory relocation costs		0.4			—			0.6			0.1		4.2		4.2
Facility carrying costs		0.5			—			0.5			—		1.6		1.6
Other costs		0.3			1.2			1.9			1.8		20.6		20.6
Restructuring total	$	5.4		$	3.1		$	13.3		$	17.4	$	109.3	$	109.3

Land and Development

Net property, plant and equipment costs	$	—		$	—		$	—		$	—	$	1.8	$	1.8
Severance and other employee costs		—			—			—			—		13.8		13.8
Other costs		—			—			—			—		5.0		5.0
Restructuring total	$	—		$	—		$	—		$	—	$	20.6	$	20.6

Corporate

Severance and other employee costs	$	—			0.1			0.9			9.0	$	60.3	$	60.3
Other costs		0.4			0.6			1.9			1.3		10.6		10.6
Restructuring total	$	0.4		$	0.7		$	2.8		$	10.3	$	70.9	$	70.9

Total

Net property, plant and equipment costs	$	—		$	(0.3	)	$	0.2		$	2.7	$	131.6	$	131.6
Severance and other employee costs		4.5			5.2			10.2			30.8		173.2		173.2
Equipment and inventory relocation costs		1.1			0.2			1.3			1.6		13.6		13.6
Facility carrying costs		0.8			0.4			1.8			1.4		23.8		25.4
Other costs		0.6			1.9			4.2			3.6		40.1		40.1
Restructuring total	$	7.0		$	7.4		$	17.7		$	40.1	$	382.3	$	383.9

We have defined “Net property, plant and equipment costs” as used in this Note 3 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 and related parts and supplies on such assets, if any.

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 potential litigation costs associated with those activities. We incur integration costs pre- and post-acquisition that reflect work being performed to facilitate merger and acquisition integration, such as work associated with information systems and other projects, including spending to support future acquisitions, and 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						Nine Months Ended
	June 30,						June 30,
	2021			2020			2021		2020
Acquisition costs	$	(0.3	)	$	(0.2	)	$	0.4	$	0.2
Integration costs		(0.2	)		2.5			1.1		15.9
Divestiture costs		0.4			—			0.6		—
Other total	$	(0.1	)	$	2.3		$	2.1	$	16.1

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 condensed consolidated statements of income (in millions):

	Nine Months Ended
	June 30,
	2021			2020
Accrual at beginning of fiscal year	$	17.2		$	32.3
Additional accruals		12.1			31.7
Payments		(14.7	)		(35.3	)
Adjustment to accruals		(2.1	)		(1.1	)
Foreign currency rate changes and other		(1.8	)		—
Accrual at June 30	$	10.7		$	27.6

Reconciliation of accruals and charges to restructuring and other costs (in millions):

	Nine Months Ended
	June 30,
	2021		2020
Additional accruals and adjustments to accruals (see table above)	$	10.0	$	30.6
Acquisition costs		0.4		0.2
Integration costs		1.1		15.9
Divestiture costs		0.6		—
Net property, plant and equipment costs		0.2		2.7
Severance and other employee costs		0.4		(0.1	)
Equipment and inventory relocation costs		1.3		1.6
Facility carrying costs		1.8		1.4
Other costs		4.0		3.9
Total restructuring and other costs	$	19.8	$	56.2

Retirement Plans

9 Months Ended

Jun. 30, 2021

Retirement Plans [Abstract]

Retirement Plans

Note 4.

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 salaried and 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. 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” and “Note 5. Retirement Plans — Multiemployer Plans” of the Notes to Consolidated Financial Statements section in the Fiscal 2020 Form 10-K for more information regarding our involvement with retirement plans and involvement with MEPPs.

MEPPs

In the normal course of business, we evaluate our potential exposure to MEPPs, including with respect to potential withdrawal liabilities. During fiscal 2018, we submitted formal notification to withdraw from the Pace Industry Union-Management Pension Fund (“PIUMPF”) and the Central States, Southeast and Southwest Areas Pension Plan (“Central States”), and recorded estimated withdrawal liabilities for each. 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 (approximately $0.7 million per month for 20 years) for the PIUMPF withdrawal liabilities in fiscal 2020, excluding the accumulated funding deficiency demands. We dispute the PIUMPF accumulated funding deficiency demands. 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.

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. We believe we are adequately reserved for this matter.

At June 30, 2021 and September 30, 2020, we had recorded withdrawal liabilities of $250.7 million and $252.0 million, respectively, including liabilities associated with PIUMPF accumulated funding deficiency demands.

With respect to certain other MEPPs, in the event we withdraw from one or more of the MEPPs in the future, it is reasonably possible that we may incur withdrawal liabilities in connection with such withdrawals. Our estimate

of any such withdrawal liabilities, both individually and in the aggregate, are not material for the remaining plans in which we participate.

Pension and Postretirement Income / Expense

The following table presents a summary of the components of net pension income (in millions):

	Three Months Ended						Nine Months Ended
	June 30,						June 30,
	2021			2020			2021			2020
Service cost	$	11.2		$	11.9		$	38.3		$	39.2
Interest cost		47.3			49.7			140.4			149.1
Expected return on plan assets		(92.0	)		(90.1	)		(276.0	)		(271.7	)
Amortization of net actuarial loss		9.8			11.4			25.7			35.1
Amortization of prior service cost		2.3			1.9			6.3			5.4
Curtailment loss		—			—			—			0.4
Company defined benefit plan income		(21.4	)		(15.2	)		(65.3	)		(42.5	)
Multiemployer pension withdrawal income		—			(2.0	)		—			(1.1	)
Multiemployer and other plans		0.4			0.3			1.2			1.0
Net pension income	$	(21.0	)	$	(16.9	)	$	(64.1	)	$	(42.6	)

The non-service elements of our pension and postretirement costs set forth in this Note 4. Retirement Plans are reflected in the condensed consolidated statements of income line item “Pension and other postretirement non-service income”. The service cost components are reflected in “Cost of goods sold” and “Selling, general and administrative, 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						Nine Months Ended
	June 30,						June 30,
	2021			2020			2021			2020
Service cost	$	0.2		$	0.3		$	0.8		$	1.0
Interest cost		1.5			1.7			4.4			5.3
Amortization of net actuarial loss (gain)		0.2			0.5			(0.4	)		0.1
Amortization of prior service credit		(0.6	)		(0.7	)		(1.8	)		(2.1	)
Net postretirement cost	$	1.3		$	1.8		$	3.0		$	4.3

Employer Contributions

During the three and nine months ended June 30, 2021, we made contributions to our qualified and supplemental defined benefit pension plans of $4.8 million and $15.6 million, respectively, and for the three and nine months ended June 30, 2020, we made contributions of $4.6 million and $17.2 million, respectively.

During the three and nine months ended June 30, 2021, we funded an aggregate of $1.6 million and $4.7 million, respectively, and for the three and nine months ended June 30, 2020, we funded an aggregate of $1.6 million and $5.3 million, respectively, to our other postretirement benefit plans.

The entire disclosure for retirement benefits.

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Income Taxes

9 Months Ended

Jun. 30, 2021

Income Tax Disclosure [Abstract]

Income Taxes

Note 5.

Income Taxes

The effective tax rate for the three and nine months ended June 30, 2021 was 23.6% and 23.4%, respectively. The effective tax rate for both periods was impacted by (i) the inclusion of state taxes, (ii) tax expense related to stock-based compensation, (iii) the exclusion of tax benefits related to losses recorded by certain foreign operations, (iv) tax expense related to remeasurement of deferred taxes as a result of a tax law

change in the United Kingdom, partially offset by (v) tax benefit related to the annual domestic federal return-to-provision true-up and (vi) research and development tax credits. In addition, the nine months ended June 30, 2021 was also impacted by tax benefit related to remeasurement of deferred taxes as a result of a state law change.

The effective tax rate for the three and nine months ended June 30, 2020 was 9.6% and 20.9%, respectively. The effective tax rate for both periods was lower than the statutory federal rate primarily due to (i) the annual domestic federal return-to-provision adjustments, (ii) adjustments to certain uncertain tax positions and (iii) research and development tax credits, partially offset by the (iv) inclusion of state taxes, (v) income derived from certain foreign jurisdictions subject to higher tax rates, (vi) the exclusion of tax benefits related to losses recorded by certain foreign operations, and (vii) tax expense related to stock based compensation.

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References + Details

Segment Information

9 Months Ended

Jun. 30, 2021

Segment Reporting [Abstract]

Segment Information

Note 6.

Segment Information

We report our financial results of operations in the following two reportable segments: Corrugated Packaging, which consists of our containerboard mills, corrugated packaging and distribution operations, as well as our merchandising displays and recycling procurement operations; and Consumer Packaging, which consists of our consumer mills and food and beverage and partition operations. Prior to the completion of our monetization program in fiscal 2020, we had a third reportable segment, Land and Development, which previously sold real estate, primarily in the Charleston, SC region. Certain income and expenses are not allocated to our segments and, thus, the information that management uses to make operating decisions and assess performance does not reflect such amounts. Items not allocated are reported as non-allocated expenses or in other line items in the table below after segment income.

The following tables show selected operating data for our segments (in millions):

	Three Months Ended						Nine Months Ended
	June 30,						June 30,
	2021			2020			2021			2020
Net sales (aggregate):
Corrugated Packaging	$	3,167.1		$	2,728.8		$	8,945.0		$	8,520.8
Consumer Packaging		1,734.7			1,552.6			4,919.7			4,705.8
Land and Development		—			—			—			18.9
Total	$	4,901.8		$	4,281.4		$	13,864.7		$	13,245.5
Less net sales (intersegment):
Corrugated Packaging	$	22.6		$	15.3		$	63.2		$	54.3
Consumer Packaging		62.9			29.8			145.9			83.9
Total	$	85.5		$	45.1		$	209.1		$	138.2
Net sales (unaffiliated customers):
Corrugated Packaging	$	3,144.5		$	2,713.5		$	8,881.8		$	8,466.5
Consumer Packaging		1,671.8			1,522.8			4,773.8			4,621.9
Land and Development		—			—			—			18.9
Total	$	4,816.3		$	4,236.3		$	13,655.6		$	13,107.3
Segment income:
Corrugated Packaging	$	321.7		$	227.9		$	742.0		$	755.8
Consumer Packaging		132.0			95.3			305.7			232.3
Land and Development		—			—			—			1.4
Segment income		453.7			323.2			1,047.7			989.5
Gain on sale of certain closed facilities		—			—			0.9			5.5
Multiemployer pension withdrawal income		—			2.0			—			1.1
Restructuring and other costs		(6.9	)		(9.7	)		(19.8	)		(56.2	)
Non-allocated expenses		(22.3	)		(18.3	)		(85.6	)		(54.1	)
Interest expense, net		(102.5	)		(92.4	)		(279.8	)		(283.2	)
Loss on extinguishment of debt		—			(0.6	)		(1.1	)		(1.1	)
Other income (expense), net		6.4			(5.0	)		13.8			(9.6	)
Income before income taxes	$	328.4		$	199.2		$	676.1		$	591.9

	Three Months Ended				Nine Months Ended
	June 30,				June 30,
	2021		2020		2021		2020
Depreciation and amortization:
Corrugated Packaging	$	232.8	$	233.1	$	695.0	$	717.0
Consumer Packaging		134.9		131.2		396.0		399.7
Corporate		1.3		1.4		3.9		4.7
Total	$	369.0	$	365.7	$	1,094.9	$	1,121.4

In October 2018, our containerboard and pulp mill located in Panama City, FL sustained extensive damage from Hurricane Michael. In fiscal 2019, we received the majority of our Hurricane Michael-related insurance proceeds. In the three months ended December 31, 2019, we received the remaining Hurricane Michael-related insurance proceeds of $32.3 million, of which $29.5 million was recorded as a reduction of cost of goods sold in our Corrugated Packaging segment. The remaining $2.8 million was deferred and recorded as a reduction of cost of goods sold in the three months ended March 31, 2020. The insurance proceeds consisted of $11.7 million of business interruption recoveries and $20.6 million for direct costs and property damage. Our condensed consolidated statement of cash flows for the nine months ended June 30, 2020 included $30.9 million in net cash provided by operating activities and $1.4 million of cash proceeds included in net cash used for investing activities related to Hurricane Michael and a $1.0 million receipt of proceeds recorded as a reduction of cost of goods sold in the third quarter of fiscal 2020 for an unrelated matter in the Consumer Packaging segment.

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

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Interest Income Expense Net [Abstract]

Interest Expense, Net

9 Months Ended

Jun. 30, 2021

Interest Expense, Net

Note 7.

Interest Expense, Net

The components of interest expense, net are as follows (in millions):

	Three Months Ended						Nine Months Ended
	June 30,						June 30,
	2021			2020			2021			2020
Interest expense	$	(114.0	)	$	(109.9	)	$	(314.4	)	$	(341.2	)
Interest income		11.5			17.5			34.6			58.0
Interest expense, net	$	(102.5	)	$	(92.4	)	$	(279.8	)	$	(283.2	)

Inventories

9 Months Ended

Jun. 30, 2021

Inventory Disclosure [Abstract]

Inventories

Note 8.

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):

	June 30, 2021			September 30, 2020
Finished goods and work in process	$	944.6		$	844.2
Raw materials		835.6			772.7
Spare parts and supplies		535.5			500.3
Inventories at FIFO cost		2,315.7			2,117.2
LIFO reserve		(170.1	)		(93.8	)
Net inventories	$	2,145.6		$	2,023.4

Property, Plant and Equipment

9 Months Ended

Jun. 30, 2021

Property Plant And Equipment [Abstract]

Property, Plant and Equipment

Note 9.

Property, Plant and Equipment

The components of property, plant and equipment were as follows (in millions):

	June 30, 2021			September 30, 2020
Property, plant and equipment at cost:
Land and buildings	$	2,600.2		$	2,524.7
Machinery and equipment		15,718.5			15,147.3
Forestlands and mineral rights		127.8			110.8
Transportation equipment		28.4			29.1
Leasehold improvements		106.2			103.6
		18,581.1			17,915.5
Less: accumulated depreciation, depletion and amortization		(7,949.8	)		(7,136.6	)
Property, plant and equipment, net	$	10,631.3		$	10,778.9

Fair Value

9 Months Ended

Jun. 30, 2021

Fair Value Disclosures [Abstract]

Fair Value

Note 10.

Fair Value

Assets and Liabilities Measured or Disclosed at Fair Value

We estimate fair values in accordance with ASC 820, “Fair Value Measurement”. See “Note 12. Fair Value” of the Notes to Consolidated Financial Statements section of the Fiscal 2020 Form 10-K for more information. We disclose the fair value of our long-term debt in “Note 11. Debt”. 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 of the Fiscal 2020 Form 10-K.

The nine months ended June 30, 2021, reflect a charge of $22.5 million associated with not exercising an option to purchase an additional equity interest in Grupo Gondi that was recorded in other income (expense), net in the second quarter of fiscal 2021.

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.

Fair Value of Nonfinancial Assets and Nonfinancial Liabilities

We measure certain nonfinancial assets and nonfinancial liabilities at fair value on a nonrecurring basis. These assets and liabilities include equity method investments 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, ROU assets related to operating leases, goodwill and other and intangible assets that are written down to fair value when they are held for sale or determined to be impaired. See “Note 3. Restructuring and Other Costs” for impairments associated with restructuring activities presented as “net property, plant and equipment costs”. During the three and nine months ended June 30, 2021 and 2020, we did not have any significant non-restructuring nonfinancial assets or liabilities 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 17, 2020, we amended the then existing agreement and increased the purchase limit to $700.0 million. The terms of the amended 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. Effective with the amended agreement, the facility is committed and has a term of 364 days. Transfers under the 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 facility that we entered into on December 4, 2020 that has a $88.5 million purchase limit, is uncommitted and has a term of one year. The customers from these facilities are not included in the Receivables Securitization Facility that is discussed in “Note 11. Debt”.

The following table presents a summary of these accounts receivable sales agreements for the nine months ended June 30, 2021 and June 30, 2020 (in millions):

	Nine Months Ended
	June 30,
	2021			2020
Receivable from financial institution at beginning of fiscal year	$	—		$	—
Receivables sold to the financial institution and derecognized		(2,011.9	)		(1,847.8	)
Receivables collected by financial institution		1,939.6			1,844.7
Cash proceeds from financial institution		72.3			3.1
Receivable from financial institution at June 30	$	—		$	—

Receivables sold under these accounts receivable sales agreements as of the respective balance sheet dates were approximately $661.7 million and $589.4 million as of June 30, 2021 and September 30, 2020, respectively.

Cash proceeds related to the receivables sold are included in cash from operating activities in the condensed consolidated statement 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 $2.8 million and $8.5 million for the three and nine months ended June 30, 2021, respectively, and $2.2 million and $10.6 million for the three and nine months ended June 30, 2020, respectively, and is recorded in “other income (expense), net” in the condensed consolidated statements of income. Although the sales are made without recourse, 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 quality of the customers underlying the receivables and the anticipated short collection period.

Commitments And Contingencies [Abstract]

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Debt

9 Months Ended

Jun. 30, 2021

Debt [Abstract]

Debt

Note 11.

Debt

See “Note 13. Debt” of the Notes to Consolidated Financial Statements section in the Fiscal 2020 Form 10-K for additional information on our debt and interest rates on that debt.

The following table shows the carrying value of the individual components of our debt (in millions):

	June 30, 2021		September 30, 2020
Public bonds due fiscal 2022	$	399.7	$	399.3
Public bonds due fiscal 2023 to 2028		3,777.1		3,773.6
Public bonds due fiscal 2029 to 2033		2,769.6		2,778.9
Public bonds due fiscal 2037 to 2047		178.3		178.6
Term loan facilities		598.9		1,547.6
Revolving credit and swing facilities		330.0		250.0
Finance lease obligations		266.7		274.8
Vendor financing and commercial card programs		106.6		89.8
International and other debt		245.7		138.0
Total debt		8,672.6		9,430.6
Less: current portion of debt		565.7		222.9
Long-term debt due after one year	$	8,106.9	$	9,207.7

A portion of the debt classified as long-term may be paid down earlier than scheduled at our discretion without penalty. Certain customary restrictive covenants govern our maximum availability under our credit facilities. We test and report our compliance with these covenants as required and were in compliance with all of our covenants at June 30, 2021.

The estimated fair value of our debt was approximately $9.6 billion as of June 30, 2021 and $10.4 billion at September 30, 2020. The fair value of our long-term debt is categorized as level 2 within the fair value hierarchy and is primarily either based on quoted prices for those or similar instruments, or approximate their carrying amount as the variable interest rates reprice frequently at observable current market rates.

On August 2, 2021, we issued a notice of redemption pursuant to the indenture governing $400 million of 4.9% bonds due March 2022 with a redemption date of September 10, 2021.

Revolving Credit Facility

On November 21, 2019, we amended our $2.0 billion unsecured revolving credit facility entered into on July 1, 2015 (the “Revolving Credit Facility”) to, among other things, increase the committed principal to $2.3 billion, increase the maximum permitted Debt to Capitalization Ratio (as defined in the credit agreement) to 0.65:1.00 and extend its maturity date to November 21, 2024. A portion of the Revolving Credit Facility may be used to fund borrowings in certain non-U.S. dollar currencies. At June 30, 2021 and September 30, 2020, there were no amounts outstanding under the facility.

Term Loans

At September 30, 2020, there was $648.9 million outstanding on the five-year unsecured term loan we entered into with Wells Fargo, as administrative agent, on March 7, 2018. During the first quarter of fiscal 2021, we paid off the term loan primarily using cash on hand.

On June 7, 2019, we entered into a $300.0 million credit agreement providing for a five-year unsecured term loan with Bank of America, N.A., as administrative agent. The facility was scheduled to mature on June 7, 2024. At September 30, 2020, the outstanding balance of this facility was $300.0 million. In December 2020 and May 2021, we repaid $50.0 million and $250.0 million, respectively, using cash and cash equivalents which resulted in the facility being terminated.

On September 27, 2019, one of our wholly-owned subsidiaries, WestRock Southeast, LLC, entered into a credit agreement (the “Farm Loan Credit Agreement”) with CoBank ACB, as administrative agent, that replaced our then-existing facility. The Farm Loan Credit Agreement provides for a seven-year senior unsecured term loan in an aggregate principal amount of $600.0 million (the “Farm Loan Credit Facility”). At any time, we may increase the principal amount by up to $300.0 million by written notice. The Farm Loan Credit Facility is guaranteed by the Company, WRKCo Inc. and WestRock RKT, LLC (“RKT”) and WestRock MWV, LLC (“MWV”, and together with RKT, the “Guarantor Subsidiaries”). The carrying value of this facility at June 30, 2021 and September 30, 2020 was $598.9 million and $598.7 million, respectively.

Receivables Securitization Facility

On March 12, 2021, we amended our existing $700.0 million receivables securitization agreement (the “Receivables Securitization Facility”), including extending its maturity to March 11, 2024, establishing the transition to the Secure Overnight Funding Rate at a future date from a blend of the market rate for asset-backed commercial paper and the one-month LIBOR rate plus a credit spread, and revising certain fees. At June 30, 2021 and September 30, 2020, 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 June 30, 2021 and September 30, 2020 were approximately $1,275.3 million and $1,128.3 million, respectively. We have continuing involvement with the underlying receivables as we provide credit and collections services pursuant to the Receivables Securitization Facility. At June 30, 2021 and September 30, 2020, there were no amounts outstanding under this facility.

European Revolving Credit Facility

On February 26, 2021, we replaced our existing revolving credit facility with Coöperatieve Rabobank U.A., New York Branch, as administrative agent. The amendments included, among other things, increasing the facility to €600.0 million while maintaining the incremental €100.0 million accordion feature. This facility provides for a three-year unsecured U.S. dollar, Euro and British Pound denominated borrowing of not more than €600.0 million

maturing on February 26, 2024. At June 30, 2021, we had borrowed $330.0 million under this facility and entered into foreign currency exchange contracts of $330.3 million as an economic hedge for the U.S. dollar denominated borrowing plus interest by a non-U.S. dollar functional currency entity. The net of gains or losses from these foreign currency exchange contracts and the changes in the remeasurement of the U.S. dollar denominated borrowing in our foreign subsidiaries have been immaterial to our condensed consolidated statements of income. At September 30, 2020, we had borrowed $250.0 million under the then-existing facility.

Commercial Paper Program

On December 7, 2018, we established an unsecured commercial paper program with WRKCo Inc. as the issuer. Under the program, we may issue 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 June 30, 2021 and September 30, 2020, there were no amounts outstanding.

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 will be repaid in equal, semiannual installments beginning on January 19, 2023 until the facility matures on January 19, 2026. The proceeds of the facility 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 will bear interest at a floating rate based on Brazil’s Certificate of Interbank Deposit rate plus a spread of 2.50%. At June 30, 2021, there was R$500.0 million ($101.1 million) outstanding.

Leases

9 Months Ended

Jun. 30, 2021

Leases [Abstract]

Leases

Note 12.

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 $81.3 million and $241.4 million during the three and nine months ended June 30, 2021, respectively. Our total lease cost, net was $78.5 million and $238.6 million during the three and nine months ended June 30, 2020, respectively. We obtained $137.6 million and $88.4 million of ROU assets in exchange for lease liabilities during the nine months ended June 30, 2021 and 2020, respectively.

Supplemental Balance Sheet Information Related to Leases

The table below presents supplemental balance sheet information related to leases (in millions):

	Condensed Consolidated Balance Sheet Caption	June 30, 2021			September 30, 2020

Operating leases:
Operating lease right-of-use asset	Other assets	$	695.7		$	658.6

Current operating lease liabilities	Other current liabilities	$	185.0		$	172.7
Operating lease liabilities	Other long-term liabilities		568.9			545.8
Total operating lease liabilities		$	753.9		$	718.5

Finance leases:
Property, plant and equipment		$	143.0		$	143.2
Accumulated depreciation			(26.0	)		(19.1	)
Property, plant and equipment, net		$	117.0		$	124.1

Current finance lease liabilities	Current portion of debt	$	8.8		$	9.0
Noncurrent finance lease liabilities	Long-term debt due after one year		257.9			265.8
Total finance lease liabilities		$	266.7		$	274.8

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.

Commitments and Contingencies

9 Months Ended

Jun. 30, 2021

Commitments and Contingencies

Note 13.

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 teammates is our first priority, and we have established safety policies, programs, procedures and training for our manufacturing operations. 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. In addition, our program includes the ongoing identification and elimination of workplace exposures that can lead to injuries and sharing of health and safety best practices. Failure to comply with applicable health and safety laws and regulations could subject us to fines, corrective actions or other sanctions.

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 lease or own. For those facilities where ACM is present and ACM is subject to regulation, we have established procedures for properly managing it.

We do not believe that future compliance with occupational health and safety laws and regulations will have a material adverse effect on our results of operations, financial condition or cash flows.

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 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.

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 sources. 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. There are other remediation costs typically associated with the cleanup of hazardous substances at our current, closed or formerly-owned facilities, and recorded as liabilities in our balance sheet. Remediation costs are recorded in our financial statements when they become probable and reasonably estimable.

See “Note 18. Commitments and Contingencies” of the Notes to Consolidated Financial Statements section in the Fiscal 2020 Form 10-K for information related to environmental matters.

As of June 30, 2021, we had $4.6 million reserved for environmental liabilities on an undiscounted basis, of which $1.7 million is included in other long-term liabilities and $2.9 million is included in other current liabilities, 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 June 30, 2021.

Litigation

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. 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. We dispute the PIUMPF accumulated funding deficiency demands. 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. See “Note 4. Retirement Plans — MEPPs” of the Notes to Condensed Consolidated Financial Statements 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 June 30, 2021, there were approximately 1,500 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 beyond our expectations, 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 June 30, 2021, we had a $15.2 million estimated liability 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 with certainty, 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.

Brazil Tax Liability

We are challenging claims by the Brazil Federal Revenue Department that we are liable for underpayment of tax, penalties and interest in relation to 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 penalties for tax years 2009 to 2012 remains before CARF.

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 was R$698 million ($141 million) as of June 30, 2021, 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, that excludes certain penalties, is included in the unrecognized tax benefits table. See “Note 6. Income Taxes” of the Notes to Consolidated Financial Statements section in the Fiscal 2020 Form 10-K. 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.

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 June 30, 2021, we had recorded $5.6 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 the 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.

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. The tax authorities in Brazil have 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 will allow us to recover tax amounts collected by the government. Due to the volume of invoices being reviewed (January 2002 to September 2019), we have recorded the estimated recoveries across several periods beginning in the fourth quarter of fiscal 2019 as we have reviewed the documents and the amount has become 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.

In the three months ended June 30, 2020, we recorded a receivable for our expected recovery and interest that consisted primarily of a $4.2 million reduction of cost of goods sold and a $6.0 million reduction of interest expense, net. In the nine months ended June 30, 2021 and 2020, we recorded a receivable for our expected recovery and interest that consisted primarily of a $0.6 million and $27.7 million reduction of cost of goods sold and a $0.3 million and $17.6 million reduction of interest expense, net, respectively. We are monitoring the status of our remaining cases, and subject to the resolution in the courts, we may record additional amounts in future periods.

Equity and Other Comprehensive Income (Loss)

9 Months Ended

Jun. 30, 2021

Equity [Abstract]

Equity and Other Comprehensive Income (Loss)

Note 14.

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 Common Stock, representing approximately 15% of our outstanding common stock, par value $0.01 per share (“Common Stock”) as of July 1, 2015. The shares of Common Stock may be repurchased over an indefinite period of time at the discretion of management. Pursuant to the program, in the nine months ended June 30, 2021 and June 30, 2020, we repurchased no shares of Common Stock. As of June 30, 2021, we had approximately 19.1 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 nine months ended June 30, 2021 and June 30, 2020 (in millions):

	Cash Flow Hedges			Defined Benefit Pension and Postretirement Plans			Foreign Currency Items			Total ⁽¹⁾
Balance at September 30, 2020	$	(5.6	)	$	(727.7	)	$	(586.6	)	$	(1,319.9	)
Other comprehensive (loss) income before reclassifications		(0.1	)		—			253.0			252.9
Amounts reclassified from accumulated other comprehensive loss		4.4			21.8			—			26.2
Net current period other comprehensive income		4.3			21.8			253.0			279.1
Balance at June 30, 2021	$	(1.3	)	$	(705.9	)	$	(333.6	)	$	(1,040.8	)

⁽¹⁾ All amounts are net of tax and noncontrolling interests.

	Cash Flow Hedges			Defined Benefit Pension and Postretirement Plans			Foreign Currency Items			Total ⁽¹⁾
Balance at September 30, 2019	$	0.7		$	(698.0	)	$	(371.9	)	$	(1,069.2	)
Other comprehensive loss before reclassifications		(10.1	)		—			(265.2	)		(275.3	)
Amounts reclassified from accumulated other comprehensive loss		2.2			28.3			—			30.5
Net current period other comprehensive (loss) income		(7.9	)		28.3			(265.2	)		(244.8	)
Reclassification of stranded tax effects		—			(73.4	)		—			(73.4	)
Balance at June 30, 2020	$	(7.2	)	$	(743.1	)	$	(637.1	)	$	(1,387.4	)

⁽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 23% to 24% for the nine months ended June 30, 2021 and 25% to 26% for the nine months ended June 30, 2020. Although we are impacted by the exchange rates of a number of currencies, foreign currency translation adjustments recorded in accumulated other comprehensive loss for the nine months ended June 30, 2021 were primarily due to gains in the Brazilian Real, Canadian dollar, Mexican Peso and British Pound, each against the U.S. dollar. Foreign currency translation adjustments recorded in accumulated other comprehensive loss for the nine months ended June 30, 2020 were primarily due to losses in the Brazilian Real, Mexican Peso, Canadian dollar and Euro, 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
	June 30, 2021								June 30, 2020
	Pretax			Tax		Net of Tax			Pretax			Tax		Net of Tax
Amortization of defined benefit pension and postretirement items: ⁽¹⁾
Actuarial losses ⁽²⁾	$	(9.3	)	$	2.1	$	(7.2	)	$	(11.4	)	$	2.6	$	(8.8	)
Prior service costs ⁽²⁾		(1.6	)		0.3		(1.3	)		(1.3	)		0.3		(1.0	)
Subtotal defined benefit plans		(10.9	)		2.4		(8.5	)		(12.7	)		2.9		(9.8	)

Derivative Instruments: ⁽¹⁾
Interest rate swap hedge loss ⁽³⁾		(2.1	)		0.6		(1.5	)		(1.4	)		0.3		(1.1	)

Total reclassifications for the period	$	(13.0	)	$	3.0	$	(10.0	)	$	(14.1	)	$	3.2	$	(10.9	)

⁽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 4. Retirement Plans” for additional details.

⁽³⁾ These accumulated other comprehensive income components are included in Interest expense, net.

	Nine Months Ended								Nine Months Ended
	June 30, 2021								June 30, 2020
	Pretax			Tax		Net of Tax			Pretax			Tax		Net of Tax
Amortization of defined benefit pension and postretirement items: ⁽¹⁾
Actuarial losses ⁽²⁾	$	(24.1	)	$	5.7	$	(18.4	)	$	(34.5	)	$	8.7	$	(25.8	)
Prior service costs ⁽²⁾		(4.4	)		1.0		(3.4	)		(3.3	)		0.8		(2.5	)
Reclassification of stranded tax effects ⁽³⁾		—			—		—			—			73.4		73.4
Subtotal defined benefit plans		(28.5	)		6.7		(21.8	)		(37.8	)		82.9		45.1

Derivative Instruments: ⁽¹⁾
Interest rate swap hedge loss ⁽⁴⁾		(6.0	)		1.6		(4.4	)		(0.4	)		0.1		(0.3	)
Natural gas commodity hedge gain ⁽⁵⁾		—			—		—			(2.6	)		0.7		(1.9	)
Subtotal cash flow hedges		(6.0	)		1.6		(4.4	)		(3.0	)		0.8		(2.2	)

Total reclassifications for the period	$	(34.5	)	$	8.3	$	(26.2	)	$	(40.8	)	$	83.7	$	42.9

⁽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 4. Retirement Plans” for additional details.

⁽³⁾ Amount reclassified to retained earnings as a result of the adoption of ASU 2018-02.

⁽⁴⁾ These accumulated other comprehensive income components are included in Interest expense, net.

⁽⁵⁾ These accumulated other comprehensive income components are included in Cost of goods sold.

Earnings Per Share

9 Months Ended

Jun. 30, 2021

Earnings Per Share [Abstract]

Earnings Per Share

Note 15.

Earnings Per Share

The restricted stock awards that we grant to non-employee directors are considered participating securities as they receive non-forfeitable rights to dividends at the same rate as our Common Stock. As participating securities, we include these instruments in the earnings allocation in computing earnings per share under the two-class method described in ASC 260, “Earnings per Share”. 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				Nine Months Ended
	June 30,				June 30,
	2021		2020		2021			2020
Numerator:
Net income attributable to common stockholders	$	250.1	$	178.5	$	514.6		$	465.1
Less: Distributed and undistributed income available to participating securities		—		—		(0.1	)		(0.1	)
Distributed and undistributed income available to common stockholders	$	250.1	$	178.5	$	514.5		$	465.0

Denominator:
Basic weighted average shares outstanding		266.5		259.4		264.7			258.9
Effect of dilutive stock options and non- participating securities		2.5		1.0		2.3			1.3
Diluted weighted average shares outstanding		269.0		260.4		267.0			260.2

Basic earnings per share attributable to common stockholders	$	0.94	$	0.69	$	1.94		$	1.80
Diluted earnings per share attributable to common stockholders	$	0.93	$	0.69	$	1.93		$	1.79

Approximately 0.5 million and 4.0 million awards in the three months ended June 30, 2021 and June 30, 2020, respectively, were not included in computing diluted earnings per share because the effect would have been antidilutive. Approximately 0.6 million and 2.2 million awards in the nine months ended June 30, 2021 and June 30, 2020, respectively, were not included in computing diluted earnings per share because the effect would have been antidilutive.

Basis of Presentation and Significant Accounting Policies (Policies)	9 Months Ended
	Jun. 30, 2021
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 condensed consolidated balance sheet at September 30, 2020 from the audited consolidated financial statements included in our Annual Report on Form 10-K for the fiscal year ended September 30, 2020 (the “Fiscal 2020 Form 10-K”). In the opinion of management, all normal recurring adjustments necessary for the fair presentation of the condensed consolidated financial statements have been included for the interim periods reported. We have condensed or omitted 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 2020 Form 10-K. The results for the three and nine months ended June 30, 2021 are not necessarily indicative of results that may be expected for the full year.
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-19”) continues to evolve. The pandemic has affected our operational and financial performance and the extent of its effect on our operational and financial performance will continue to depend on future developments, which are highly uncertain and cannot be predicted with confidence, including the duration, scope and severity of the pandemic (including due to new variants such as Delta), the actions taken to contain or mitigate its impact (including the distribution and effectiveness of vaccines), and the direct and indirect economic effects of the pandemic and related containment measures and government responses, among others. At June 30, 2021, we evaluated the then current economic environment, including our assessment of the impact of COVID-19, as well as the ransomware incident discussed below, and there were no indicators of impairment of our long-lived assets, including goodwill, that required a quantitative test to be performed. Our estimates involve numerous assumptions about the future growth and potential volatility in revenues and costs, capital expenditures, industry and global economic factors, interest rate environment and future business strategy. Accordingly, our accounting estimates may materially change from period to period due to changing market factors, including those driven by COVID-19. We will continue to monitor future events, changes in circumstances and the potential impact thereof, including performing our annual goodwill impairment assessment in the fourth quarter of fiscal 2021. If actual results are not consistent with our assumptions and estimates, we may be exposed to impairment losses that could be material. See “Note 1. Description of Business and Summary of Significant Accounting Policies — Goodwill and Long-Lived Assets” in the Fiscal 2020 Form 10-K for additional information regarding the results of, and our methods and assumptions applied to perform, our goodwill impairment testing in fiscal 2020.
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, including shutting down certain systems out of an abundance of caution, as well as taking steps to supplement existing security monitoring, scanning and protective measures. We notified law enforcement and contacted our customers to apprise them of the situation. We undertook extensive efforts to identify, contain and recover from this incident quickly and securely. Our teams worked to maintain our business operations and minimize the impact on our customers and teammates. All systems are back in service. All of our mills and converting locations began producing and shipping paper and packaging at pre-ransomware levels in March 2021 or earlier. Our mill system production was approximately 115,000 tons lower than planned for the quarter ended March 31, 2021 as a result of this incident. While shipments from some of our facilities initially lagged behind production levels, this gap closed as systems were restored during the second quarter of fiscal 2021. In locations where technology issues were identified, we used alternative methods, in many cases manual methods, to process and ship orders. We systematically brought our information systems back online in a controlled, phased approach. We estimate the segment income impact of the lost sales and operational disruption of this incident on our operations in the second quarter of fiscal 2021 was approximately $50 million, as well as approximately $20 million of ransomware recovery costs, primarily professional fees. In addition, we incurred approximately $9 million of ransomware recovery costs in the third quarter of fiscal 2021. We expect to recover substantially all of the ransomware losses from cyber and business interruption insurance in future periods. Disputes over the extent of insurance coverage for claims are not uncommon, and there will be a time lag between the initial incurrence of costs and the receipt of any insurance proceeds. In response to the ransomware event, we accelerated information technology investments that we had previously planned to make in future periods in order to further strengthen our information security infrastructure. We engaged a leading cybersecurity defense firm that completed a forensics investigation of the ransomware incident and we are taking appropriate actions in response to the findings. For example, in the short-term, we reset all credentials Company-wide and strengthened security tooling across our servers and workstations. Longer term, in collaboration with our strategic partners, we established a roadmap to advance the maturity and effectiveness of our information security and resiliency capabilities. This roadmap includes initiatives to further strengthen our information security posture across the Company, and to enable us to potentially detect, respond to and recover from security and technical incidents in a faster and more effective manner. More specifically, we are progressing projects to bolster our security monitoring capabilities, strengthen our access controls, reduce risks associated with third-parties, and to enhance the information security of our mills and plants.
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 2020 Form 10-K for a summary of our significant accounting policies.
New Accounting Standards - Recently Adopted	New Accounting Standards — Recently Adopted In November 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2018-18 “Collaborative Arrangements (Topic 808): Clarifying the Interaction Between Topic 808 and Topic 606”, which provides targeted amendments to Accounting Standards Codification (“ASC”) 808, “Collaborative arrangements” and ASC 606, “Revenues from Contracts with Customers” (“ASC 606”). The amendments in this ASU require transactions between participants in a collaborative arrangement to be accounted for under ASC 606 only when the counterparty is a customer. We adopted the provisions of ASU 2018-18 on October 1, 2020. The adoption did not have a material impact on our consolidated financial statements. In October 2018, the FASB issued ASU 2018-17 “Consolidation: Targeted Improvements to Related Party Guidance for Variable Interest Entities”. This ASU changes how entities evaluate decision-making fees under the variable interest entity guidance. To determine whether decision-making fees represent a variable interest, an entity considers indirect interests held through related parties under common control on a proportionate basis, rather than in their entirety, as currently required under generally accepted accounting principles in the U.S. (“GAAP”). We adopted the provisions of ASU 2018-17 on October 1, 2020. The adoption did not have a material impact on our consolidated financial statements. In August 2018, the FASB issued ASU 2018-15 “Intangibles – Goodwill and Other – Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract”. The amendments in this ASU align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). The accounting for the service element of a hosting arrangement that is a service contract is not affected by these amendments. We adopted the provisions of ASU 2018-15 prospectively on October 1, 2020. The adoption did not have a material impact on our consolidated financial statements. In August 2018, the FASB issued ASU 2018-14 “Compensation – Retirement Benefits – Defined Benefit Plans – General (Subtopic 715-20): Changes to the Disclosure Requirements for Defined Benefit Plans”. The amendments in this ASU modify the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans to remove disclosures that no longer are considered cost beneficial, clarify the specific requirements of disclosures and add disclosure requirements identified as relevant. We adopted the provisions of ASU 2018-14 retrospectively on October 1, 2020. In June 2016, the FASB issued ASU 2016-13 “Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments (Topic 326)” (“ASU 2016-13”), which modifies the measurement of expected credit losses of certain financial instruments and replaces the incurred loss model with a model that reflects expected credit losses. In April 2019, the FASB issued ASU 2019-04 “Codification Improvements to Topic 326, Financial Instruments – Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments” (“ASU 2019-04”), which addresses issues related to accrued interest receivable balances, recoveries, variable interest rates and prepayments, among other things. In May 2019, the FASB issued ASU 2019-05 “Financial Instruments – Credit Losses (Topic 326): Targeted Transition Relief” (“ASU 2019-05”), which provides targeted transition relief allowing entities to make an irrevocable one-time election upon adoption of the new credit losses standard to measure financial assets previously measured at amortized cost (except held-to-maturity securities) using the fair value option. In November 2019, the FASB issued ASU 2019-11 “Codification Improvements to Topic 326, Financial Instruments – Credit Losses” (“ASU 2019-11”), which makes certain narrow-scope amendments to Topic 326, including allowing entities to exclude accrued interest amounts from various required disclosures under Topic 326. In February 2020, the FASB issued ASU 2020-02 “Financial Instruments – Credit Losses (Topic 326) and Leases (Topic 842)” (“ASU 2020-02”), which adds and amends paragraphs in the ASC to reflect the issuance of SEC Staff Accounting Bulletin No. 119 primarily related to the new credit losses standard. The provisions of ASU 2019-04, ASU 2019-05, ASU 2019-11 and ASU 2020-02 related to Topic 326 are effective concurrent with the adoption of ASU 2016-13. We adopted ASU 2016-13 and its subsequent revisions using the modified retrospective transition approach on October 1, 2020. The adoption of ASU 2016-13 and its subsequent revisions resulted in us recognizing a cumulative effect adjustment of $3.8 million (net of tax) decrease to opening balance of retained earnings related to our allowance for doubtful accounts primarily for our trade accounts receivable balance.
New Accounting Standards - Recently Issued	New Accounting Standards — Recently Issued 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 the London Interbank Offered Rate (“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 can be adopted after their respective issuance dates through December 31, 2022. We are evaluating the impact of these ASUs. In December 2019, the FASB issued ASU 2019-12 “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes”. This ASU simplifies the accounting for income taxes by removing certain exceptions to the general principles in Topic 740 under GAAP. This ASU also improves consistent application of and simplifies GAAP for other areas of Topic 740 by clarifying and amending existing guidance. This ASU is effective for fiscal years beginning after December 15, 2020 (fiscal 2022 for us) and interim periods within those fiscal years. Early adoption is permitted. While we are still finalizing our evaluation of the impact of this ASU, we do not expect the adoption of this ASU to have a material impact on our consolidated financial statements.

Revenue Recognition (Tables)

9 Months Ended

Jun. 30, 2021

Revenue From Contract With Customer [Abstract]

Schedule of Disaggregates Revenue by Geographical Market and Product Type (Segment)

The tables below disaggregate our revenue by geographical market and product type (segment).

	Three Months Ended June 30, 2021
(In millions)	Corrugated Packaging		Consumer Packaging		Intersegment Sales			Total

Primary Geographical Markets
North America	$	3,020.9	$	1,353.9	$	(85.1	)	$	4,289.7
South America		127.2		17.7		—			144.9
Europe		1.5		285.6		(0.1	)		287.0
Asia Pacific		17.5		77.5		(0.3	)		94.7
Total	$	3,167.1	$	1,734.7	$	(85.5	)	$	4,816.3

	Nine Months Ended June 30, 2021
(In millions)	Corrugated Packaging		Consumer Packaging		Intersegment Sales			Total

Primary Geographical Markets
North America	$	8,588.2	$	3,839.6	$	(208.3	)	$	12,219.5
South America		304.7		63.0		—			367.7
Europe		3.5		800.8		(0.2	)		804.1
Asia Pacific		48.6		216.3		(0.6	)		264.3
Total	$	8,945.0	$	4,919.7	$	(209.1	)	$	13,655.6

	Three Months Ended June 30, 2020
(In millions)	Corrugated Packaging		Consumer Packaging		Land and Development		Intersegment Sales			Total

Primary Geographical Markets
North America	$	2,632.4	$	1,238.4	$	—	$	(44.8	)	$	3,826.0
South America		87.8		14.1		—		—			101.9
Europe		0.6		233.8		—		(0.2	)		234.2
Asia Pacific		8.0		66.3		—		(0.1	)		74.2
Total	$	2,728.8	$	1,552.6	$	—	$	(45.1	)	$	4,236.3

	Nine Months Ended June 30, 2020
(In millions)	Corrugated Packaging		Consumer Packaging		Land and Development		Intersegment Sales			Total

Primary Geographical Markets
North America	$	8,187.0	$	3,718.8	$	18.9	$	(137.7	)	$	11,787.0
South America		296.1		52.9		—		—			349.0
Europe		4.9		731.8		—		(0.2	)		736.5
Asia Pacific		32.8		202.3		—		(0.3	)		234.8
Total	$	8,520.8	$	4,705.8	$	18.9	$	(138.2	)	$	13,107.3

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 condensed consolidated balance sheet.

(In millions)	Contract Assets (Short-Term)		Contract Liabilities (Short-Term)

Beginning balance - October 1, 2020	$	185.8	$	12.0
Ending balance - June 30, 2021		193.9		22.7
Increase	$	8.1	$	10.7

Restructuring and Other Costs (Tables)

9 Months Ended

Jun. 30, 2021

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					Nine Months Ended
	June 30,					June 30,
	2021			2020		2021		2020
Restructuring	$	7.0		$	7.4	$	17.7	$	40.1
Other		(0.1	)		2.3		2.1		16.1
Restructuring and other costs	$	6.9		$	9.7	$	19.8	$	56.2

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 nine months ended June 30, 2021 and 2020, the cumulative recorded amount since we started the initiatives and our estimate of the total we expect to incur (in millions):

	Three Months Ended						Nine Months Ended
	June 30,						June 30,
	2021			2020			2021			2020		Cumulative		Total Expected
Corrugated Packaging

Net property, plant and equipment costs	$	—		$	(0.3	)	$	—		$	2.2	$	94.4	$	94.4
Severance and other employee costs		0.3			3.2			(0.8	)		6.8		51.6		51.6
Equipment and inventory relocation costs		0.7			0.2			0.7			1.5		9.4		9.4
Facility carrying costs		0.3			0.4			1.3			1.4		22.2		23.8
Other costs		(0.1	)		0.1			0.4			0.5		3.9		3.9
Restructuring total	$	1.2		$	3.6		$	1.6		$	12.4	$	181.5	$	183.1

Consumer Packaging

Net property, plant and equipment costs	$	—		$	—		$	0.2		$	0.5	$	35.4	$	35.4
Severance and other employee costs		4.2			1.9			10.1			15.0		47.5		47.5
Equipment and inventory relocation costs		0.4			—			0.6			0.1		4.2		4.2
Facility carrying costs		0.5			—			0.5			—		1.6		1.6
Other costs		0.3			1.2			1.9			1.8		20.6		20.6
Restructuring total	$	5.4		$	3.1		$	13.3		$	17.4	$	109.3	$	109.3

Land and Development

Net property, plant and equipment costs	$	—		$	—		$	—		$	—	$	1.8	$	1.8
Severance and other employee costs		—			—			—			—		13.8		13.8
Other costs		—			—			—			—		5.0		5.0
Restructuring total	$	—		$	—		$	—		$	—	$	20.6	$	20.6

Corporate

Severance and other employee costs	$	—			0.1			0.9			9.0	$	60.3	$	60.3
Other costs		0.4			0.6			1.9			1.3		10.6		10.6
Restructuring total	$	0.4		$	0.7		$	2.8		$	10.3	$	70.9	$	70.9

Total

Net property, plant and equipment costs	$	—		$	(0.3	)	$	0.2		$	2.7	$	131.6	$	131.6
Severance and other employee costs		4.5			5.2			10.2			30.8		173.2		173.2
Equipment and inventory relocation costs		1.1			0.2			1.3			1.6		13.6		13.6
Facility carrying costs		0.8			0.4			1.8			1.4		23.8		25.4
Other costs		0.6			1.9			4.2			3.6		40.1		40.1
Restructuring total	$	7.0		$	7.4		$	17.7		$	40.1	$	382.3	$	383.9

Schedule of Acquisition, Integration and Divestiture Costs

The following table presents our acquisition, integration and divestiture costs (in millions):

	Three Months Ended						Nine Months Ended
	June 30,						June 30,
	2021			2020			2021		2020
Acquisition costs	$	(0.3	)	$	(0.2	)	$	0.4	$	0.2
Integration costs		(0.2	)		2.5			1.1		15.9
Divestiture costs		0.4			—			0.6		—
Other total	$	(0.1	)	$	2.3		$	2.1	$	16.1

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 condensed consolidated statements of income (in millions):

	Nine Months Ended
	June 30,
	2021			2020
Accrual at beginning of fiscal year	$	17.2		$	32.3
Additional accruals		12.1			31.7
Payments		(14.7	)		(35.3	)
Adjustment to accruals		(2.1	)		(1.1	)
Foreign currency rate changes and other		(1.8	)		—
Accrual at June 30	$	10.7		$	27.6

Reconciliation of accruals and charges to restructuring and other costs (in millions):

	Nine Months Ended
	June 30,
	2021		2020
Additional accruals and adjustments to accruals (see table above)	$	10.0	$	30.6
Acquisition costs		0.4		0.2
Integration costs		1.1		15.9
Divestiture costs		0.6		—
Net property, plant and equipment costs		0.2		2.7
Severance and other employee costs		0.4		(0.1	)
Equipment and inventory relocation costs		1.3		1.6
Facility carrying costs		1.8		1.4
Other costs		4.0		3.9
Total restructuring and other costs	$	19.8	$	56.2

Retirement Plans (Tables)

9 Months Ended

Jun. 30, 2021

Retirement Plans [Abstract]

Summary of Components of Net Pension Income and Summary of Components of Postretirement Benefit Cost

Pension and Postretirement Income / Expense

The following table presents a summary of the components of net pension income (in millions):

	Three Months Ended						Nine Months Ended
	June 30,						June 30,
	2021			2020			2021			2020
Service cost	$	11.2		$	11.9		$	38.3		$	39.2
Interest cost		47.3			49.7			140.4			149.1
Expected return on plan assets		(92.0	)		(90.1	)		(276.0	)		(271.7	)
Amortization of net actuarial loss		9.8			11.4			25.7			35.1
Amortization of prior service cost		2.3			1.9			6.3			5.4
Curtailment loss		—			—			—			0.4
Company defined benefit plan income		(21.4	)		(15.2	)		(65.3	)		(42.5	)
Multiemployer pension withdrawal income		—			(2.0	)		—			(1.1	)
Multiemployer and other plans		0.4			0.3			1.2			1.0
Net pension income	$	(21.0	)	$	(16.9	)	$	(64.1	)	$	(42.6	)

The following table presents a summary of the components of the net postretirement cost (in millions):

	Three Months Ended						Nine Months Ended
	June 30,						June 30,
	2021			2020			2021			2020
Service cost	$	0.2		$	0.3		$	0.8		$	1.0
Interest cost		1.5			1.7			4.4			5.3
Amortization of net actuarial loss (gain)		0.2			0.5			(0.4	)		0.1
Amortization of prior service credit		(0.6	)		(0.7	)		(1.8	)		(2.1	)
Net postretirement cost	$	1.3		$	1.8		$	3.0		$	4.3

Segment Information (Tables)

9 Months Ended

Jun. 30, 2021

Segment Reporting [Abstract]

Certain Operating Data for Segments

The following tables show selected operating data for our segments (in millions):

	Three Months Ended						Nine Months Ended
	June 30,						June 30,
	2021			2020			2021			2020
Net sales (aggregate):
Corrugated Packaging	$	3,167.1		$	2,728.8		$	8,945.0		$	8,520.8
Consumer Packaging		1,734.7			1,552.6			4,919.7			4,705.8
Land and Development		—			—			—			18.9
Total	$	4,901.8		$	4,281.4		$	13,864.7		$	13,245.5
Less net sales (intersegment):
Corrugated Packaging	$	22.6		$	15.3		$	63.2		$	54.3
Consumer Packaging		62.9			29.8			145.9			83.9
Total	$	85.5		$	45.1		$	209.1		$	138.2
Net sales (unaffiliated customers):
Corrugated Packaging	$	3,144.5		$	2,713.5		$	8,881.8		$	8,466.5
Consumer Packaging		1,671.8			1,522.8			4,773.8			4,621.9
Land and Development		—			—			—			18.9
Total	$	4,816.3		$	4,236.3		$	13,655.6		$	13,107.3
Segment income:
Corrugated Packaging	$	321.7		$	227.9		$	742.0		$	755.8
Consumer Packaging		132.0			95.3			305.7			232.3
Land and Development		—			—			—			1.4
Segment income		453.7			323.2			1,047.7			989.5
Gain on sale of certain closed facilities		—			—			0.9			5.5
Multiemployer pension withdrawal income		—			2.0			—			1.1
Restructuring and other costs		(6.9	)		(9.7	)		(19.8	)		(56.2	)
Non-allocated expenses		(22.3	)		(18.3	)		(85.6	)		(54.1	)
Interest expense, net		(102.5	)		(92.4	)		(279.8	)		(283.2	)
Loss on extinguishment of debt		—			(0.6	)		(1.1	)		(1.1	)
Other income (expense), net		6.4			(5.0	)		13.8			(9.6	)
Income before income taxes	$	328.4		$	199.2		$	676.1		$	591.9

	Three Months Ended				Nine Months Ended
	June 30,				June 30,
	2021		2020		2021		2020
Depreciation and amortization:
Corrugated Packaging	$	232.8	$	233.1	$	695.0	$	717.0
Consumer Packaging		134.9		131.2		396.0		399.7
Corporate		1.3		1.4		3.9		4.7
Total	$	369.0	$	365.7	$	1,094.9	$	1,121.4

Interest Expense, Net (Tables)

9 Months Ended

Jun. 30, 2021

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						Nine Months Ended
	June 30,						June 30,
	2021			2020			2021			2020
Interest expense	$	(114.0	)	$	(109.9	)	$	(314.4	)	$	(341.2	)
Interest income		11.5			17.5			34.6			58.0
Interest expense, net	$	(102.5	)	$	(92.4	)	$	(279.8	)	$	(283.2	)

Inventories (Tables)

9 Months Ended

Jun. 30, 2021

Inventory Disclosure [Abstract]

Schedule of Inventories

The components of inventories were as follows (in millions):

	June 30, 2021			September 30, 2020
Finished goods and work in process	$	944.6		$	844.2
Raw materials		835.6			772.7
Spare parts and supplies		535.5			500.3
Inventories at FIFO cost		2,315.7			2,117.2
LIFO reserve		(170.1	)		(93.8	)
Net inventories	$	2,145.6		$	2,023.4

Property, Plant and Equipment (Tables)

9 Months Ended

Jun. 30, 2021

Property Plant And Equipment [Abstract]

Schedule of Property, Plant and Equipment

The components of property, plant and equipment were as follows (in millions):

	June 30, 2021			September 30, 2020
Property, plant and equipment at cost:
Land and buildings	$	2,600.2		$	2,524.7
Machinery and equipment		15,718.5			15,147.3
Forestlands and mineral rights		127.8			110.8
Transportation equipment		28.4			29.1
Leasehold improvements		106.2			103.6
		18,581.1			17,915.5
Less: accumulated depreciation, depletion and amortization		(7,949.8	)		(7,136.6	)
Property, plant and equipment, net	$	10,631.3		$	10,778.9

Fair Value (Tables)

9 Months Ended

Jun. 30, 2021

Fair Value Disclosures [Abstract]

Summary of Accounts Receivable Sales Agreement

The following table presents a summary of these accounts receivable sales agreements for the nine months ended June 30, 2021 and June 30, 2020 (in millions):

	Nine Months Ended
	June 30,
	2021			2020
Receivable from financial institution at beginning of fiscal year	$	—		$	—
Receivables sold to the financial institution and derecognized		(2,011.9	)		(1,847.8	)
Receivables collected by financial institution		1,939.6			1,844.7
Cash proceeds from financial institution		72.3			3.1
Receivable from financial institution at June 30	$	—		$	—

Debt (Tables)

9 Months Ended

Jun. 30, 2021

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):

	June 30, 2021		September 30, 2020
Public bonds due fiscal 2022	$	399.7	$	399.3
Public bonds due fiscal 2023 to 2028		3,777.1		3,773.6
Public bonds due fiscal 2029 to 2033		2,769.6		2,778.9
Public bonds due fiscal 2037 to 2047		178.3		178.6
Term loan facilities		598.9		1,547.6
Revolving credit and swing facilities		330.0		250.0
Finance lease obligations		266.7		274.8
Vendor financing and commercial card programs		106.6		89.8
International and other debt		245.7		138.0
Total debt		8,672.6		9,430.6
Less: current portion of debt		565.7		222.9
Long-term debt due after one year	$	8,106.9	$	9,207.7

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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Summary of Supplemental Balance Sheet Information Related to Leases

Leases (Tables)

9 Months Ended

Jun. 30, 2021

Leases [Abstract]

Supplemental Balance Sheet Information Related to Leases

The table below presents supplemental balance sheet information related to leases (in millions):

	Condensed Consolidated Balance Sheet Caption	June 30, 2021			September 30, 2020

Operating leases:
Operating lease right-of-use asset	Other assets	$	695.7		$	658.6

Current operating lease liabilities	Other current liabilities	$	185.0		$	172.7
Operating lease liabilities	Other long-term liabilities		568.9			545.8
Total operating lease liabilities		$	753.9		$	718.5

Finance leases:
Property, plant and equipment		$	143.0		$	143.2
Accumulated depreciation			(26.0	)		(19.1	)
Property, plant and equipment, net		$	117.0		$	124.1

Current finance lease liabilities	Current portion of debt	$	8.8		$	9.0
Noncurrent finance lease liabilities	Long-term debt due after one year		257.9			265.8
Total finance lease liabilities		$	266.7		$	274.8

Equity and Other Comprehensive Income (Loss) (Tables)

9 Months Ended

Jun. 30, 2021

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 nine months ended June 30, 2021 and June 30, 2020 (in millions):

	Cash Flow Hedges			Defined Benefit Pension and Postretirement Plans			Foreign Currency Items			Total ⁽¹⁾
Balance at September 30, 2020	$	(5.6	)	$	(727.7	)	$	(586.6	)	$	(1,319.9	)
Other comprehensive (loss) income before reclassifications		(0.1	)		—			253.0			252.9
Amounts reclassified from accumulated other comprehensive loss		4.4			21.8			—			26.2
Net current period other comprehensive income		4.3			21.8			253.0			279.1
Balance at June 30, 2021	$	(1.3	)	$	(705.9	)	$	(333.6	)	$	(1,040.8	)

⁽¹⁾ All amounts are net of tax and noncontrolling interests.

	Cash Flow Hedges			Defined Benefit Pension and Postretirement Plans			Foreign Currency Items			Total ⁽¹⁾
Balance at September 30, 2019	$	0.7		$	(698.0	)	$	(371.9	)	$	(1,069.2	)
Other comprehensive loss before reclassifications		(10.1	)		—			(265.2	)		(275.3	)
Amounts reclassified from accumulated other comprehensive loss		2.2			28.3			—			30.5
Net current period other comprehensive (loss) income		(7.9	)		28.3			(265.2	)		(244.8	)
Reclassification of stranded tax effects		—			(73.4	)		—			(73.4	)
Balance at June 30, 2020	$	(7.2	)	$	(743.1	)	$	(637.1	)	$	(1,387.4	)

⁽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
	June 30, 2021								June 30, 2020
	Pretax			Tax		Net of Tax			Pretax			Tax		Net of Tax
Amortization of defined benefit pension and postretirement items: ⁽¹⁾
Actuarial losses ⁽²⁾	$	(9.3	)	$	2.1	$	(7.2	)	$	(11.4	)	$	2.6	$	(8.8	)
Prior service costs ⁽²⁾		(1.6	)		0.3		(1.3	)		(1.3	)		0.3		(1.0	)
Subtotal defined benefit plans		(10.9	)		2.4		(8.5	)		(12.7	)		2.9		(9.8	)

Derivative Instruments: ⁽¹⁾
Interest rate swap hedge loss ⁽³⁾		(2.1	)		0.6		(1.5	)		(1.4	)		0.3		(1.1	)

Total reclassifications for the period	$	(13.0	)	$	3.0	$	(10.0	)	$	(14.1	)	$	3.2	$	(10.9	)

⁽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 4. Retirement Plans” for additional details.

⁽³⁾ These accumulated other comprehensive income components are included in Interest expense, net.

	Nine Months Ended								Nine Months Ended
	June 30, 2021								June 30, 2020
	Pretax			Tax		Net of Tax			Pretax			Tax		Net of Tax
Amortization of defined benefit pension and postretirement items: ⁽¹⁾
Actuarial losses ⁽²⁾	$	(24.1	)	$	5.7	$	(18.4	)	$	(34.5	)	$	8.7	$	(25.8	)
Prior service costs ⁽²⁾		(4.4	)		1.0		(3.4	)		(3.3	)		0.8		(2.5	)
Reclassification of stranded tax effects ⁽³⁾		—			—		—			—			73.4		73.4
Subtotal defined benefit plans		(28.5	)		6.7		(21.8	)		(37.8	)		82.9		45.1

Derivative Instruments: ⁽¹⁾
Interest rate swap hedge loss ⁽⁴⁾		(6.0	)		1.6		(4.4	)		(0.4	)		0.1		(0.3	)
Natural gas commodity hedge gain ⁽⁵⁾		—			—		—			(2.6	)		0.7		(1.9	)
Subtotal cash flow hedges		(6.0	)		1.6		(4.4	)		(3.0	)		0.8		(2.2	)

Total reclassifications for the period	$	(34.5	)	$	8.3	$	(26.2	)	$	(40.8	)	$	83.7	$	42.9

⁽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 4. Retirement Plans” for additional details.

⁽³⁾ Amount reclassified to retained earnings as a result of the adoption of ASU 2018-02.

⁽⁴⁾ These accumulated other comprehensive income components are included in Interest expense, net.

⁽⁵⁾ These accumulated other comprehensive income components are included in Cost of goods sold.

Earnings Per Share (Tables)

9 Months Ended

Jun. 30, 2021

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				Nine Months Ended
	June 30,				June 30,
	2021		2020		2021			2020
Numerator:
Net income attributable to common stockholders	$	250.1	$	178.5	$	514.6		$	465.1
Less: Distributed and undistributed income available to participating securities		—		—		(0.1	)		(0.1	)
Distributed and undistributed income available to common stockholders	$	250.1	$	178.5	$	514.5		$	465.0

Denominator:
Basic weighted average shares outstanding		266.5		259.4		264.7			258.9
Effect of dilutive stock options and non- participating securities		2.5		1.0		2.3			1.3
Diluted weighted average shares outstanding		269.0		260.4		267.0			260.2

Basic earnings per share attributable to common stockholders	$	0.94	$	0.69	$	1.94		$	1.80
Diluted earnings per share attributable to common stockholders	$	0.93	$	0.69	$	1.93		$	1.79

Basis of Presentation and Significant Accounting Policies - Additional Information (Details) $ in Millions		3 Months Ended
	Oct. 01, 2020 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($) T
Basis of Presentation and Significant Accounting Policies [Line Items]
Lost production from ransomware incident to date \| T			115,000
Impact of lost sales and operational disruption			$ 50.0
Ransomware recovery costs		$ 9.0	$ 20.0
ASU 2016-13 [Member]
Basis of Presentation and Significant Accounting Policies [Line Items]
Reclassification of adoption effect of credit loss standard to retained earnings	$ 3.8

Revenue Recognition - Additional Information (Details)	12 Months Ended
Revenue Recognition - Additional Information (Details)	Sep. 30, 2021 USD ($)
Scenario Forecast [Member]
Disaggregation Of Revenue [Line Items]
Land and development sales	$ 0

Revenue Recognition - Schedule of Disaggregates Revenue by Geographical Market and Product Type (Segment) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation Of Revenue [Line Items]
Net sales	$ 4,816.3	$ 4,236.3	$ 13,655.6	$ 13,107.3
Corrugated Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	3,167.1	2,728.8	8,945.0	8,520.8
Consumer Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	1,734.7	1,552.6	4,919.7	4,705.8
Land and Development [Member]
Disaggregation Of Revenue [Line Items]
Net sales				18.9
Intersegment Sales [Member]
Disaggregation Of Revenue [Line Items]
Net sales	(85.5)	(45.1)	(209.1)	(138.2)
Intersegment Sales [Member] \| Corrugated Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	(22.6)	(15.3)	(63.2)	(54.3)
Intersegment Sales [Member] \| Consumer Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	(62.9)	(29.8)	(145.9)	(83.9)
North America [Member]
Disaggregation Of Revenue [Line Items]
Net sales	4,289.7	3,826.0	12,219.5	11,787.0
North America [Member] \| Corrugated Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	3,020.9	2,632.4	8,588.2	8,187.0
North America [Member] \| Consumer Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	1,353.9	1,238.4	3,839.6	3,718.8
North America [Member] \| Land and Development [Member]
Disaggregation Of Revenue [Line Items]
Net sales				18.9
North America [Member] \| Intersegment Sales [Member]
Disaggregation Of Revenue [Line Items]
Net sales	(85.1)	(44.8)	(208.3)	(137.7)
South America [Member]
Disaggregation Of Revenue [Line Items]
Net sales	144.9	101.9	367.7	349.0
South America [Member] \| Corrugated Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	127.2	87.8	304.7	296.1
South America [Member] \| Consumer Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	17.7	14.1	63.0	52.9
Europe [Member]
Disaggregation Of Revenue [Line Items]
Net sales	287.0	234.2	804.1	736.5
Europe [Member] \| Corrugated Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	1.5	0.6	3.5	4.9
Europe [Member] \| Consumer Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	285.6	233.8	800.8	731.8
Europe [Member] \| Intersegment Sales [Member]
Disaggregation Of Revenue [Line Items]
Net sales	(0.1)	(0.2)	(0.2)	(0.2)
Asia Pacific [Member]
Disaggregation Of Revenue [Line Items]
Net sales	94.7	74.2	264.3	234.8
Asia Pacific [Member] \| Corrugated Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	17.5	8.0	48.6	32.8
Asia Pacific [Member] \| Consumer Packaging [Member]
Disaggregation Of Revenue [Line Items]
Net sales	77.5	66.3	216.3	202.3
Asia Pacific [Member] \| Intersegment Sales [Member]
Disaggregation Of Revenue [Line Items]
Net sales	$ (0.3)	$ (0.1)	$ (0.6)	$ (0.3)

Revenue Recognition - Summary of Opening and Closing Balances of Contract Assets and Contract Liabilities (Details) $ in Millions	9 Months Ended
	Jun. 30, 2021 USD ($)
Disaggregation Of Revenue [Abstract]
Short-Term Contract Assets, Beginning balance	$ 185.8
Increase in Short-Term Contract Assets	8.1
Short-Term Contract Assets, Ending balance	193.9
Short-Term Contract Liabilities, Beginning balance	12.0
Increase in Short-Term Contract Liabilities	10.7
Short-Term Contract Liabilities, Ending balance	$ 22.7

Restructuring and Other Costs - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Restructuring And Related Activities [Abstract]
Restructuring and other costs	$ 6.9	$ 9.7	$ 19.8	$ 56.2

Restructuring and Other Costs - Schedule of Restructuring and Other Costs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Restructuring And Related Activities [Abstract]
Restructuring	$ 7.0	$ 7.4	$ 17.7	$ 40.1
Other	(0.1)	2.3	2.1	16.1
Restructuring and other costs	$ 6.9	$ 9.7	$ 19.8	$ 56.2

Restructuring and Other Costs - Schedule of Restructuring Charges Related to Active Restructuring Initiatives (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	$ 7.0	$ 7.4	$ 17.7	$ 40.1
Restructuring and Related Cost, Cost Incurred to Date	382.3		382.3
Restructuring and Related Cost, Expected Cost	383.9		383.9
Net Property, Plant and Equipment [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost		(0.3)	0.2	2.7
Restructuring and Related Cost, Cost Incurred to Date	131.6		131.6
Restructuring and Related Cost, Expected Cost	131.6		131.6
Severance and Other Employee Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	4.5	5.2	10.2	30.8
Restructuring and Related Cost, Cost Incurred to Date	173.2		173.2
Restructuring and Related Cost, Expected Cost	173.2		173.2
Equipment and Inventory Relocation Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	1.1	0.2	1.3	1.6
Restructuring and Related Cost, Cost Incurred to Date	13.6		13.6
Restructuring and Related Cost, Expected Cost	13.6		13.6
Facility Carrying Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0.8	0.4	1.8	1.4
Restructuring and Related Cost, Cost Incurred to Date	23.8		23.8
Restructuring and Related Cost, Expected Cost	25.4		25.4
Other Costs Related to Restructuring and Other Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0.6	1.9	4.2	3.6
Restructuring and Related Cost, Cost Incurred to Date	40.1		40.1
Restructuring and Related Cost, Expected Cost	40.1		40.1
Corporate, Non-Segment [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0.4	0.7	2.8	10.3
Restructuring and Related Cost, Cost Incurred to Date	70.9		70.9
Restructuring and Related Cost, Expected Cost	70.9		70.9
Corporate, Non-Segment [Member] \| Severance and Other Employee Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost		0.1	0.9	9.0
Restructuring and Related Cost, Cost Incurred to Date	60.3		60.3
Restructuring and Related Cost, Expected Cost	60.3		60.3
Corporate, Non-Segment [Member] \| Other Costs Related to Restructuring and Other Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0.4	0.6	1.9	1.3
Restructuring and Related Cost, Cost Incurred to Date	10.6		10.6
Restructuring and Related Cost, Expected Cost	10.6		10.6
Corrugated Packaging [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	1.2	3.6	1.6	12.4
Restructuring and Related Cost, Cost Incurred to Date	181.5		181.5
Restructuring and Related Cost, Expected Cost	183.1		183.1
Corrugated Packaging [Member] \| Net Property, Plant and Equipment [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost		(0.3)		2.2
Restructuring and Related Cost, Cost Incurred to Date	94.4		94.4
Restructuring and Related Cost, Expected Cost	94.4		94.4
Corrugated Packaging [Member] \| Severance and Other Employee Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0.3	3.2	(0.8)	6.8
Restructuring and Related Cost, Cost Incurred to Date	51.6		51.6
Restructuring and Related Cost, Expected Cost	51.6		51.6
Corrugated Packaging [Member] \| Equipment and Inventory Relocation Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0.7	0.2	0.7	1.5
Restructuring and Related Cost, Cost Incurred to Date	9.4		9.4
Restructuring and Related Cost, Expected Cost	9.4		9.4
Corrugated Packaging [Member] \| Facility Carrying Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0.3	0.4	1.3	1.4
Restructuring and Related Cost, Cost Incurred to Date	22.2		22.2
Restructuring and Related Cost, Expected Cost	23.8		23.8
Corrugated Packaging [Member] \| Other Costs Related to Restructuring and Other Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	(0.1)	0.1	0.4	0.5
Restructuring and Related Cost, Cost Incurred to Date	3.9		3.9
Restructuring and Related Cost, Expected Cost	3.9		3.9
Consumer Packaging [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	5.4	3.1	13.3	17.4
Restructuring and Related Cost, Cost Incurred to Date	109.3		109.3
Restructuring and Related Cost, Expected Cost	109.3		109.3
Consumer Packaging [Member] \| Net Property, Plant and Equipment [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost			0.2	0.5
Restructuring and Related Cost, Cost Incurred to Date	35.4		35.4
Restructuring and Related Cost, Expected Cost	35.4		35.4
Consumer Packaging [Member] \| Severance and Other Employee Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	4.2	1.9	10.1	15.0
Restructuring and Related Cost, Cost Incurred to Date	47.5		47.5
Restructuring and Related Cost, Expected Cost	47.5		47.5
Consumer Packaging [Member] \| Equipment and Inventory Relocation Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0.4		0.6	0.1
Restructuring and Related Cost, Cost Incurred to Date	4.2		4.2
Restructuring and Related Cost, Expected Cost	4.2		4.2
Consumer Packaging [Member] \| Facility Carrying Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0.5		0.5
Restructuring and Related Cost, Cost Incurred to Date	1.6		1.6
Restructuring and Related Cost, Expected Cost	1.6		1.6
Consumer Packaging [Member] \| Other Costs Related to Restructuring and Other Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0.3	$ 1.2	1.9	$ 1.8
Restructuring and Related Cost, Cost Incurred to Date	20.6		20.6
Restructuring and Related Cost, Expected Cost	20.6		20.6
Land and Development [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	20.6		20.6
Restructuring and Related Cost, Expected Cost	20.6		20.6
Land and Development [Member] \| Net Property, Plant and Equipment [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	1.8		1.8
Restructuring and Related Cost, Expected Cost	1.8		1.8
Land and Development [Member] \| Severance and Other Employee Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	13.8		13.8
Restructuring and Related Cost, Expected Cost	13.8		13.8
Land and Development [Member] \| Other Costs Related to Restructuring and Other Costs [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	5.0		5.0
Restructuring and Related Cost, Expected Cost	$ 5.0		$ 5.0

Restructuring and Other Costs - Schedule of Acquisition,Integration and Divestiture Costs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Restructuring Cost And Reserve [Line Items]
Acquisition costs			$ 0.4	$ 0.2
Integration costs			1.1	15.9
Divestiture costs			0.6
Other total	$ (0.1)	$ 2.3	2.1	16.1
Other Segments [Member]
Restructuring Cost And Reserve [Line Items]
Acquisition costs	(0.3)	(0.2)	0.4	0.2
Integration costs	(0.2)	2.5	1.1	15.9
Divestiture costs	0.4		0.6
Other total	$ (0.1)	$ 2.3	$ 2.1	$ 16.1

Restructuring and Other Costs - Schedule of Changes in Restructuring Accrual Charges (Details) - USD ($) $ in Millions	9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Restructuring And Other Costs [Abstract]
Accrual at beginning of fiscal year	$ 17.2	$ 32.3
Additional accruals	12.1	31.7
Payments	(14.7)	(35.3)
Adjustment to accruals	(2.1)	(1.1)
Foreign currency rate changes and other	(1.8)
Accrual at June 30	$ 10.7	$ 27.6

Restructuring and Other Costs - Schedule of Reconciliation of Accruals and Charges (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Restructuring And Other Costs [Abstract]
Additional accruals and adjustments to accruals (see table above)			$ 10.0	$ 30.6
Acquisition costs			0.4	0.2
Integration costs			1.1	15.9
Divestiture costs			0.6
Net property, plant and equipment costs			0.2	2.7
Severance and other employee costs			0.4	(0.1)
Equipment and inventory relocation costs			1.3	1.6
Facility carrying costs			1.8	1.4
Other costs			4.0	3.9
Restructuring and other costs	$ 6.9	$ 9.7	$ 19.8	$ 56.2

Retirement Plans - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Sep. 30, 2020	Apr. 30, 2020	Feb. 29, 2020
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Multiemployer Plans, Withdrawal Obligation	$ 250.7		$ 250.7		$ 252.0
Pace Industry Union Management Pension Fund [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Withdrawal obligation, per month			$ 0.7
Periods of Payments Used to Calculate Withdrawal Liability in Connection with PIUMPF Withdrawal			20 years
Withdrawal obligation accumulated funding deficiency							$ 51.2
Pace Industry Union Management Pension Fund [Member] \| Subsidiary [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Withdrawal obligation accumulated funding deficiency						$ 1.3
Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions by employer to pension and supplemental retirement plans	4.8	$ 4.6	$ 15.6	$ 17.2
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	$ 1.6	$ 1.6	$ 4.7	$ 5.3

Retirement Plans - Summary of Components of Net Pension Income and Summary of Components of Postretirement Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Defined Benefit Plan Disclosure [Line Items]
Multiemployer pension withdrawal income		$ (2.0)		$ (1.1)
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 11.2	11.9	$ 38.3	39.2
Interest cost	47.3	49.7	140.4	149.1
Expected return on plan assets	(92.0)	(90.1)	(276.0)	(271.7)
Amortization of net actuarial loss (gain)	9.8	11.4	25.7	35.1
Amortization of prior service cost (credit)	2.3	1.9	6.3	5.4
Curtailment loss				0.4
Company defined benefit plan income	(21.4)	(15.2)	(65.3)	(42.5)
Multiemployer pension withdrawal income		(2.0)		(1.1)
Multiemployer and other plans	0.4	0.3	1.2	1.0
Net pension (income) cost	(21.0)	(16.9)	(64.1)	(42.6)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.2	0.3	0.8	1.0
Interest cost	1.5	1.7	4.4	5.3
Amortization of net actuarial loss (gain)	0.2	0.5	(0.4)	0.1
Amortization of prior service cost (credit)	(0.6)	(0.7)	(1.8)	(2.1)
Net pension (income) cost	$ 1.3	$ 1.8	$ 3.0	$ 4.3

Income Taxes - Additional Information (Details)	3 Months Ended		9 Months Ended
Income Taxes - Additional Information (Details)	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Tax Disclosure [Abstract]
Effective tax rates	23.60%	9.60%	23.40%	20.90%

Segment Information - Additional Information (Details) $ in Millions	3 Months Ended			9 Months Ended
	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jun. 30, 2021 USD ($) segment	Jun. 30, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments \| segment				2
Insurance proceeds received, net cash used for investing activities				$ 1.7	$ 2.4
Corrugated Packaging [Member] \| Hurricane Michael [Member]
Segment Reporting Information [Line Items]
Insurance proceeds received			$ 32.3
Deferred insurance proceeds			2.8
Deferred insurance proceeds recognized in cost of goods sold		$ 2.8
Insurance proceeds from business interruption recoveries			11.7
Insurance proceeds for direct costs and property damage			20.6
Insurance proceeds received, net cash provided by operating activities					30.9
Insurance proceeds received, net cash used for investing activities					$ 1.4
Corrugated Packaging [Member] \| Hurricane Michael [Member] \| Cost of Goods Sold [Member]
Segment Reporting Information [Line Items]
Reduction of cost of goods sold			$ 29.5
Consumer Packaging [Member] \| Cost of Goods Sold [Member]
Segment Reporting Information [Line Items]
Reduction of cost of goods sold	$ 1.0

Segment Information - Certain Operating Data for Segments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information [Line Items]
Net sales	$ 4,816.3	$ 4,236.3	$ 13,655.6	$ 13,107.3
Gain on sale of certain closed facilities			0.9	5.5
Multiemployer pension withdrawal income		2.0		1.1
Restructuring and other costs	(6.9)	(9.7)	(19.8)	(56.2)
Interest expense, net	(102.5)	(92.4)	(279.8)	(283.2)
Loss on extinguishment of debt		(0.6)	(1.1)	(1.1)
Other income (expense), net	6.4	(5.0)	13.8	(9.6)
Income before income taxes	328.4	199.2	676.1	591.9
Depreciation, depletion and amortization	369.0	365.7	1,094.9	1,121.4
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	4,901.8	4,281.4	13,864.7	13,245.5
Segment income	453.7	323.2	1,047.7	989.5
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	(85.5)	(45.1)	(209.1)	(138.2)
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Non-allocated expenses	(22.3)	(18.3)	(85.6)	(54.1)
Interest expense, net	(102.5)	(92.4)	(279.8)	(283.2)
Corrugated Packaging [Member]
Segment Reporting Information [Line Items]
Net sales	3,167.1	2,728.8	8,945.0	8,520.8
Depreciation, depletion and amortization	232.8	233.1	695.0	717.0
Corrugated Packaging [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	3,167.1	2,728.8	8,945.0	8,520.8
Segment income	321.7	227.9	742.0	755.8
Corrugated Packaging [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	(22.6)	(15.3)	(63.2)	(54.3)
Corrugated Packaging [Member] \| Unaffiliated Customers [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	3,144.5	2,713.5	8,881.8	8,466.5
Consumer Packaging [Member]
Segment Reporting Information [Line Items]
Net sales	1,734.7	1,552.6	4,919.7	4,705.8
Depreciation, depletion and amortization	134.9	131.2	396.0	399.7
Consumer Packaging [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	1,734.7	1,552.6	4,919.7	4,705.8
Segment income	132.0	95.3	305.7	232.3
Consumer Packaging [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	(62.9)	(29.8)	(145.9)	(83.9)
Consumer Packaging [Member] \| Unaffiliated Customers [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	1,671.8	1,522.8	4,773.8	4,621.9
Land and Development [Member]
Segment Reporting Information [Line Items]
Net sales				18.9
Land and Development [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales				18.9
Segment income				1.4
Land and Development [Member] \| Unaffiliated Customers [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales				18.9
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Depreciation, depletion and amortization	$ 1.3	$ 1.4	$ 3.9	$ 4.7

Interest Expense, Net - Summary of Components of Interest Expense, Net (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Interest Income Expense Net [Abstract]
Interest expense	$ (114.0)	$ (109.9)	$ (314.4)	$ (341.2)
Interest income	11.5	17.5	34.6	58.0
Interest expense, net	$ (102.5)	$ (92.4)	$ (279.8)	$ (283.2)

Inventories - Schedule of Inventories (Details) - USD ($) $ in Millions	Jun. 30, 2021	Sep. 30, 2020
Inventories [Abstract]
Finished goods and work in process	$ 944.6	$ 844.2
Raw materials	835.6	772.7
Spare parts and supplies	535.5	500.3
Inventories at FIFO cost	2,315.7	2,117.2
LIFO reserve	(170.1)	(93.8)
Net inventories	$ 2,145.6	$ 2,023.4

Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Millions	Jun. 30, 2021	Sep. 30, 2020
Property, plant and equipment at cost:
Property, plant and equipment, at cost	$ 18,581.1	$ 17,915.5
Less: accumulated depreciation, depletion and amortization	(7,949.8)	(7,136.6)
Property, plant and equipment, net	10,631.3	10,778.9
Land and Buildings [Member]
Property, plant and equipment at cost:
Property, plant and equipment, at cost	2,600.2	2,524.7
Machinery and Equipment [Member]
Property, plant and equipment at cost:
Property, plant and equipment, at cost	15,718.5	15,147.3
Forestlands and Mineral Rights [Member]
Property, plant and equipment at cost:
Property, plant and equipment, at cost	127.8	110.8
Transportation Equipment [Member]
Property, plant and equipment at cost:
Property, plant and equipment, at cost	28.4	29.1
Leasehold Improvements [Member]
Property, plant and equipment at cost:
Property, plant and equipment, at cost	$ 106.2	$ 103.6

Fair Value - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 04, 2020	Sep. 30, 2020	Sep. 17, 2020
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Maximum eligible receivables that may be sold					$ 88.5		$ 700.0
Receivables sold under accounts receivable sales agreement	$ 661.7		$ 661.7			$ 589.4
Estimated loss on sale of accounts receivable by quarter	$ 2.8	$ 2.2	8.5	$ 10.6
Grupo Gondi [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Charge on not exercising option to purchase additional equity interest in joint venture			$ 22.5

Fair Value - Summary of Accounts Receivable Sales Agreement (Details) - USD ($) $ in Millions	9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Receivables sold to the financial institution and derecognized	$ (2,011.9)	$ (1,847.8)
Receivables collected by financial institution	1,939.6	1,844.7
Cash proceeds from financial institution	$ 72.3	$ 3.1

Debt - Schedule of Carrying Value of Individual Components of Debt (Details) - USD ($) $ in Millions	Jun. 30, 2021	Sep. 30, 2020
Debt Instrument [Line Items]
Total debt	$ 8,672.6	$ 9,430.6
Less: current portion of debt	565.7	222.9
Long-term debt due after one year	8,106.9	9,207.7
Notes Due Fiscal 2022 [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Total debt	399.7	399.3
Notes Due Fiscal 2023 to 2028 [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Total debt	3,777.1	3,773.6
Notes Due Fiscal 2029 to 2033 [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Total debt	2,769.6	2,778.9
Notes Due Fiscal 2037 to 2047 [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Total debt	178.3	178.6
Term Loan Facilities [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Total debt	598.9	1,547.6
Revolving Credit and Swing Facilities [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Total debt	330.0	250.0
Finance Lease Obligations [Member] \| Secured Debt [Member]
Debt Instrument [Line Items]
Total debt	266.7	274.8
Vendor Financing and Commercial Card Programs [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Total debt	106.6	89.8
International and Other Debt [Member]
Debt Instrument [Line Items]
Total debt	$ 245.7	$ 138.0

Debt - Additional Information (Details)									1 Months Ended		12 Months Ended
Debt - Additional Information (Details)	Aug. 02, 2021 USD ($)	Mar. 12, 2021 USD ($)	Feb. 26, 2021 EUR (€)	Jan. 18, 2021 BRL (R$)	Nov. 21, 2019 USD ($)	Sep. 27, 2019 USD ($)	Jun. 07, 2019 USD ($)	Dec. 07, 2018 USD ($)	May 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2021 BRL (R$)	Jul. 01, 2015 USD ($)
Debt Instrument [Line Items]
Fair value of debt											$ 10,400,000,000	$ 9,600,000,000
Revolving Credit Facility [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Credit Facility, maximum borrowing capacity					$ 2,300,000,000									$ 2,000,000,000.0
Credit facility, maturity date					Nov. 21, 2024
Long-term debt											0	0
4.9% Bonds Due March 2022 [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Indenture governing amount	$ 400,000,000
Debt instrument, interest rate	4.90%
Redemption date	Sep. 10, 2021
Wells Fargo Bank NA Credit Facility [Member] \| Terminated Unsecured Term Loan Facility [Member]
Debt Instrument [Line Items]
Long-term debt											$ 648,900,000
Debt instrument, maturity period											5 years
Bank of America Five Year Term Loan [Member] \| Terminated Unsecured Term Loan Facility [Member]
Debt Instrument [Line Items]
Repayments of debt									$ 250,000,000.0	$ 50,000,000.0
Bank of America Five Year Term Loan [Member] \| Unsecured [Member] \| Terminated Unsecured Term Loan Facility [Member]
Debt Instrument [Line Items]
Credit Facility, maximum borrowing capacity							$ 300,000,000.0
Credit facility, maturity date							Jun. 07, 2024
Long-term debt											$ 300,000,000.0
Debt instrument, maturity period							5 years
Farm Credit Facility [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Credit Facility, maximum borrowing capacity						$ 600,000,000.0
Long-term debt											598,700,000	598,900,000
Debt Instrument, Term, in Years						7 years
Receivables Securitization Facility [Member] \| Secured Debt [Member]
Debt Instrument [Line Items]
Long-term debt											0	0
Receivables backed financing, maximum borrowing amount		$ 700,000,000.0
Debt instrument, amended maturity date		Mar. 11, 2024
Debt instrument, maximum borrowing capacity, amount											700,000,000.0	700,000,000.0
Loans and Leases Receivable, Collateral for Secured Borrowings											1,128,300,000	1,275,300,000
Receivables Securitization Facility [Member] \| Secured Debt [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Variable rate basis		a blend of the market rate for asset-backed commercial paper and the one-month LIBOR rate plus a credit spread
Cooperatieve Rabobank U.A., New York Branch European Revolving Credit Facility [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Credit Facility, maximum borrowing capacity \| €			€ 600,000,000.0
Credit facility, maturity date			Feb. 26, 2024
Long-term debt											250,000,000.0	330,000,000.0
Debt instrument, maturity period			3 years
Incremental line of credit \| €			€ 100,000,000.0
Line of credit facility, maximum Euro denominated borrowing capacity \| €			€ 600,000,000.0
Cooperatieve Rabobank U.A., New York Branch European Revolving Credit Facility [Member] \| Unsecured Debt [Member] \| Foreign Exchange Contract [Member]
Debt Instrument [Line Items]
Amount of foreign exchange contracts												330,300,000
Commercial Paper [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Long-term debt											$ 0	0
Aggregate Principal Amount of Short-term Unsecured Commercial Paper Program, Maximum								$ 1,000,000,000.0
Debt Instrument, notice period for termination								30 days
Brazil Export Credit Note [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Credit Facility, maximum borrowing capacity \| R$				R$ 500,000,000.0
Credit facility, maturity date				Jan. 19, 2026
Long-term debt												$ 101,100,000	R$ 500,000,000.0
Credit facility semiannual installments repayment beginning date				Jan. 19, 2023
Credit facility basis spread on floating rate				2.50%
Maximum [Member] \| Revolving Credit Facility [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Credit facility, maximum permitted debt to capitalization ratio					0.65
Maximum [Member] \| Farm Credit Facility [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Credit facility, amount of potential increase to the principal amount						$ 300,000,000.0
Maximum [Member] \| Commercial Paper [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt instrument, maturity period								397 days

Leases - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Leases [Abstract]
Total lease cost, net	$ 81.3	$ 78.5	$ 241.4	$ 238.6
ROU asset obtained in exchange for operating lease liability			$ 137.6	$ 88.4

Leases - Summary of Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Millions	Jun. 30, 2021	Sep. 30, 2020
Supplementary Information Balance Sheets [Abstract]
Operating lease right-of-use asset	$ 695.7	$ 658.6
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Operating lease right-of-use asset	Operating lease right-of-use asset
Current operating lease liabilities	$ 185.0	$ 172.7
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Current operating lease liabilities	Current operating lease liabilities
Operating lease liabilities	$ 568.9	$ 545.8
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Operating lease liabilities	Operating lease liabilities
Total operating lease liabilities	$ 753.9	$ 718.5
Property, plant and equipment	143.0	143.2
Accumulated depreciation	(26.0)	(19.1)
Property, plant and equipment, net	117.0	124.1
Current finance lease liabilities	$ 8.8	$ 9.0
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Current finance lease liabilities	Current finance lease liabilities
Noncurrent finance lease liabilities	$ 257.9	$ 265.8
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Noncurrent finance lease liabilities	Noncurrent finance lease liabilities
Total finance lease liabilities	$ 266.7	$ 274.8

Commitments and Contingencies - Additional Information (Details) R$ in Millions	3 Months Ended	9 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) lawsuit Subsidiary	Jun. 30, 2021 BRL (R$) Subsidiary	Jun. 30, 2020 USD ($)	Apr. 30, 2020 USD ($)	Feb. 29, 2020 USD ($)
Commitments and Contingencies [Line Items]
Accrual for Environmental Loss Contingencies		$ 4,600,000
Guarantor Obligations, Current Carrying Value		5,600,000
Indirect tax claim - reduction of cost of goods sold	$ 4,200,000	600,000		$ 27,700,000
Indirect tax claim - reduction of interest expense, net	$ 6,000,000.0	300,000		$ 17,600,000
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]
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense		$ 141,000,000	R$ 698
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		2003 to 2008	2003 to 2008
Tax claim and conversion, tax penalties relating to tax years description		2009 to 2012	2009 to 2012
Tax claim and conversion proceedings covering tax years description		2003 to 2008 and 2009 to 2012	2003 to 2008 and 2009 to 2012
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		1,500
Estimated liability for litigation		$ 15,200,000
Other Long Term Liabilities [Member]
Commitments and Contingencies [Line Items]
Accrual for Environmental Loss Contingencies		1,700,000
Other Current Liabilities [Member]
Commitments and Contingencies [Line Items]
Accrual for Environmental Loss Contingencies		$ 2,900,000

Equity and Other Comprehensive Income (Loss) - Additional Information (Details) - $ / shares shares in Millions	9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Sep. 30, 2020	Jul. 01, 2015
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Stock repurchase program, number of shares authorized to be repurchased				40.0
Common Stock, Par or Stated Value Per Share	$ 0.01		$ 0.01	$ 0.01
Authorized share repurchase as a percentage of common stock outstanding				15.00%
Stock repurchase program, remaining number of shares authorized to be repurchased	19.1
Treasury stock, shares, acquired	0.0	0.0
Minimum [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Effective Tax Rate, Net of Tax Components of Other Comprehensive Income	23.00%	25.00%
Maximum [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Effective Tax Rate, Net of Tax Components of Other Comprehensive Income	24.00%	26.00%

Equity and Other Comprehensive Income (Loss) - Schedule of Changes in Accumulated Other Comprehensive Loss, Net of Tax (Details) - USD ($)
$ in Millions

9 Months Ended

Jun. 30, 2021

Jun. 30, 2020

Accumulated Other Comprehensive Income (Loss) [Line Items]

Other comprehensive (loss) income before reclassifications

^[1]

$ (1,319.9)

$ (1,069.2)

^[1]

252.9

(275.3)

Amounts reclassified from accumulated other comprehensive loss

^[1]

26.2

30.5

Net current period other comprehensive (loss) income

^[1]

279.1

(244.8)

^[1]

(73.4)

Accumulated Net Gain (Loss) from Designated or Quality Cash Flow Hedges [Member]

^[1]

(1,040.8)

(1,387.4)

Accumulated Other Comprehensive Income (Loss) [Line Items]

Other comprehensive (loss) income before reclassifications

(5.6)

0.7

(0.1)

(10.1)

Amounts reclassified from accumulated other comprehensive loss

4.4

2.2

Net current period other comprehensive (loss) income

4.3

(7.9)

Accumulated Defined Benefit Plans Adjustment [Member]

(1.3)

(7.2)

Accumulated Other Comprehensive Income (Loss) [Line Items]

Amounts reclassified from accumulated other comprehensive loss

(727.7)

(698.0)

21.8

28.3

Net current period other comprehensive (loss) income

21.8

28.3

(73.4)

Accumulated Translation Adjustment [Member]

(705.9)

(743.1)

Accumulated Other Comprehensive Income (Loss) [Line Items]

Other comprehensive (loss) income before reclassifications

(586.6)

(371.9)

253.0

(265.2)

Net current period other comprehensive (loss) income

253.0

(265.2)

$ (333.6)

$ (637.1)

[1]	All amounts are net of tax and noncontrolling interests.

Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

+ References + Details

Equity and Other Comprehensive Income (Loss) - Summary of Reclassification out of Accumulated Other Comprehensive Loss (Details) - USD ($)
$ in Millions

3 Months Ended

9 Months Ended

Jun. 30, 2021

Jun. 30, 2020

Jun. 30, 2021

Jun. 30, 2020

Amortization and settlement recognition of net actuarial loss, included in pension cost

$ 7.4

$ 9.0

$ 18.8

$ 26.2

Amortization of prior service costs, Net of Tax

1.3

1.0

3.4

2.5

Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax

1.5

1.0

4.4

2.2

Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]

^[1]

73.4

Parent [Member]

Amortization of net actuarial loss, Pre-Tax Amount

^[2],[3]

(9.3)

(11.4)

(24.1)

(34.5)

Amortization of net actuarial loss, Tax

^[2],[3]

2.1

2.6

5.7

8.7

Amortization and settlement recognition of net actuarial loss, included in pension cost

^[2],[3]

(7.2)

(8.8)

(18.4)

(25.8)

Amortization of prior service costs, Pre-Tax Amount

^[2],[3]

(1.6)

(1.3)

(4.4)

(3.3)

Amortization of prior service costs, Tax

^[2],[3]

0.3

1.0

0.8

Amortization of prior service costs, Net of Tax

^[2],[3]

(1.3)

(1.0)

(3.4)

(2.5)

Defined Benefit Plans, before Tax

^[2]

(10.9)

(12.7)

(28.5)

(37.8)

Defined Benefit Plans, Tax

^[2]

2.4

2.9

6.7

82.9

Defined Benefit Plans, Net of Tax

^[2]

(8.5)

(9.8)

(21.8)

45.1

Total Reclassifications From Other Comprehensive Income Before Tax

^[2]

(13.0)

(14.1)

(34.5)

(40.8)

Total Reclassifications From Other Comprehensive Income Tax Portion

^[2]

3.0

3.2

8.3

83.7

Total Reclassifications From Other Comprehensive Income Net of Tax

^[2]

(10.0)

(10.9)

(26.2)

42.9

Parent [Member] | ASU 2018-02 [Member]

Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]