Post (POST) 10-K 17 Nov 22 2022 FY Annual report Financial data

Cover

Cover - USD ($)	12 Months Ended
	Sep. 30, 2022	Nov. 14, 2022	Mar. 31, 2022
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Sep. 30, 2022
Document Transition Report	false
Entity File Number	1-35305
Entity Registrant Name	POST HOLDINGS, INC.
Entity Incorporation, State or Country Code	MO
Entity Tax Identification Number	45-3355106
Entity Address, Address Line One	2503 S. Hanley Road
Entity Address, City or Town	St. Louis,
Entity Address, State or Province	MO
Entity Address, Postal Zip Code	63144
City Area Code	314
Local Phone Number	644-7600
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	POST
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 3,888,949,528
Entity Common Stock, Shares Outstanding (in shares)		58,603,600
Documents Incorporated by Reference	Certain portions of the registrant’s definitive proxy statement for its 2023 annual meeting of shareholders, to be filed with the Securities and Exchange Commission within 120 days after September 30, 2022, are incorporated by reference into Part III of this report.
Entity Central Index Key	0001530950
Current Fiscal Year End Date	--09-30
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false

Audit Information

Audit Information	12 Months Ended
	Sep. 30, 2022
Auditor [Abstract]
Auditor Firm ID	238
Auditor Name	PricewaterhouseCoopers LLP
Auditor Location	St. Louis, Missouri

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Net Sales	$ 5,851.2	$ 4,980.7	$ 4,711
Cost of goods sold	4,383.7	3,552.6	3,261.6
Gross Profit	1,467.5	1,428.1	1,449.4
Selling, general and administrative expenses	904.7	807	782.5
Amortization of intangible assets	146	143.2	138.1
Other operating expense (income), net	1.2	(9.8)	(7.7)
Operating Profit	415.6	487.7	536.5
Interest expense, net	317.8	332.6	333.9
(Gain) loss on extinguishment of debt, net	(72.6)	93.2	72.9
(Income) expense on swaps, net	(268)	(122.8)	187.1
Gain on investment in BellRing	(437.1)	0	0
Other income, net	(19.8)	(29.3)	(11.5)
Earnings (Loss) before Income Taxes and Equity Method Loss	895.3	214	(45.9)
Income tax expense (benefit)	85.7	58.2	(21.3)
Equity method loss, net of tax	67.1	43.9	30.9
Net Earnings (Loss) from Continuing Operations, Including Noncontrolling Interests	742.5	111.9	(55.5)
Less: Net earnings attributable to noncontrolling interests from continuing operations	7.5	7	1
Net Earnings (Loss) from Continuing Operations	735	104.9	(56.5)
Net earnings from discontinued operations, net of tax and noncontrolling interest	21.6	61.8	57.3
Net Earnings	$ 756.6	$ 166.7	$ 0.8
Earnings per Common share:
Earnings (Loss) from Continuing Operations, Per Basic Share	$ 12.07	$ 1.46	$ (0.82)
Earnings (Loss) from Continuing Operations, Per Diluted Share	11.75	1.44	(0.82)
Discontinued Operation, Earnings (Loss) from Discontinued Operation, Net of Tax, Per Basic Share	0.35	0.96	0.83
Discontinued Operation, Earnings (Loss) from Discontinued Operation, Net of Tax, Per Diluted Share	0.34	0.94	0.83
Basic earnings per common share (in usd per share)	12.42	2.42	0.01
Diluted earnings per common share (in usd per share)	$ 12.09	$ 2.38	$ 0.01
Weighted-Average Common Shares Outstanding:
Weighted-average shares for basic earnings per share	60.9	64.2	68.9
Weighted-average shares for diluted earnings per share	62.7	65.3	68.9

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net Earnings	$ 756.6	$ 166.7	$ 0.8
Net earnings attributable to noncontrolling interests from continuing operations	7.5	7	1
Net earnings attributable to noncontrolling interest from discontinued operations	11.8	33	27.2
Net Earnings Including Noncontrolling Interest	775.9	206.7	29
Pension and postretirement benefits adjustments:
Unrealized pension and postretirement benefit obligations	(24)	(8.1)	(36.8)
Reclassifications to net earnings	(1.9)	(0.6)	(2.2)
Hedging adjustments:
Net gain (loss) on derivatives	0	0	22.5
Reclassifications to net earnings	7.1	2.3	8.2
Foreign currency translation adjustments:
Unrealized foreign currency translation adjustments	(293.9)	77.4	72.3
Tax benefit (expense) on pension and postretirement benefits adjustments:
Unrealized pension and postretirement benefit obligations	6.7	1.9	7.5
Reclassifications to net earnings	0.4	0.2	0.6
Tax benefit (expense) on hedging adjustments:
Net gain on derivatives	0	0	(5.4)
Reclassifications to net earnings	(1.8)	(0.6)	(1.9)
Total Other Comprehensive (Loss) Income Including Noncontrolling Interests	(307.4)	72.5	64.8
Less: Comprehensive income attributable to noncontrolling interests	20	40.3	25.5
Total Comprehensive Income	$ 448.5	$ 238.9	$ 68.3

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2022	Sep. 30, 2021
Current Assets
Cash and cash equivalents	$ 586.5	$ 664.5
Restricted cash	3.6	7.1
Receivables, net	544.2	452.4
Inventories	549.1	476.6
Investment in BellRing	94.8	0
Current investments held in trust	346.8	0
Current assets of discontinued operations	0	385.7
Prepaid expenses and other current assets	98.4	99.8
Total Current Assets	2,223.4	2,086.1
Property, net	1,751.9	1,830.5
Goodwill	4,349.6	4,501.6
Other intangible assets, net	2,712.2	2,924.4
Equity method investments	4.1	70.7
Investments held in trust	0	345
Other assets of discontinued operations	0	308.4
Other assets	266.8	348
Total Assets	11,308	12,414.7
Current Liabilities
Current portion of long-term debt	1.1	1.1
Accounts payable	452.7	384.2
Current liabilities of discontinued operations	0	248.9
Other current liabilities	370	415
Total Current Liabilities	823.8	1,049.2
Long-term debt	5,956.6	6,441.6
Deferred income taxes	688.4	729.1
Other liabilities of discontinued operations	0	627.7
Other liabilities	266.9	507.9
Total Liabilities	7,735.7	9,355.5
Commitments and Contingencies
Redeemable noncontrolling interest	306.6	305
Shareholders’ Equity
Preferred stock, $0.01 par value, 50.0 shares authorized, zero shares issued and outstanding in each year	0	0
Common stock, $0.01 par value, 300.0 shares authorized, 58.7 and 63.1 shares outstanding, respectively	0.9	0.9
Additional paid-in capital	4,748.2	4,253.5
Retained earnings	1,109	347.3
Accumulated other comprehensive (loss) income	(262.9)	42.9
Treasury stock, at cost, 26.9 and 22.0 shares, respectively	(2,341.2)	(1,902.2)
Total Shareholders’ Equity Excluding Noncontrolling Interests	3,254	2,742.4
Noncontrolling interests	11.7	11.8
Total Shareholders’ Equity	3,265.7	2,754.2
Total Liabilities and Shareholders’ Equity	$ 11,308	$ 12,414.7

Consolidated Balance Sheets Con

Consolidated Balance Sheets Consolidated Balance Sheet (Parentheticals) - $ / shares shares in Millions	Sep. 30, 2022	Sep. 30, 2021
Preferred Stock
Par value of preferred stock	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	50	50
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Common Stock
Par value of common stock	$ 0.01	$ 0.01
Common Stock, Shares Authorized	300	300
Common Stock, Shares, Issued	58.7	63.1
Treasury Stock
Treasury Stock, Shares	26.9	22

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Cash Flows from Operating Activities:
Net earnings (loss) from continuing operations, including noncontrolling interests	$ 742.5	$ 111.9	$ (55.5)
Adjustments to reconcile net earnings including noncontrolling interest to net cash provided by operating activities:
Depreciation and amortization	380.2	366.5	345
(Gain) loss on extinguishment of debt, net	(72.6)	93.2	72.9
Unrealized (gain) loss on interest rate swaps, foreign exchange contracts and warrant liabilities, net	(296.2)	(170.5)	124.5
Gain on investment in BellRing	(437.1)	0	0
Non-cash stock-based compensation expense	65.8	48.7	43.3
Equity method loss, net of tax	67.1	43.9	30.9
Deferred income taxes	(9.7)	68.2	(44.1)
Other, net	0.9	(8.8)	(3.5)
Other changes in operating assets and liabilities, net of business acquisitions, divestitures and held for sale assets and liabilities:
(Increase) decrease in receivables	(102)	(117.1)	22.7
(Increase) decrease in inventories	(86.8)	22.1	6.9
Decrease (increase) in prepaid expenses and other current assets	0.3	(68.4)	(27.1)
Decrease in other assets	28.8	5.9	2.4
Increase (decrease) in accounts payable and other current liabilities	106.4	(48.7)	(10.8)
(Decrease) increase in non-current liabilities	(3.4)	15.2	20.8
Net Cash Provided by Operating Activities - continuing operations	384.2	362.1	528.4
Net Cash (Used In) Provided by Operating Activities - discontinued operations	(1.6)	226.1	97.2
Net Cash Provided by Operating Activities	382.6	588.2	625.6
Cash Flows from Investing Activities
Business acquisitions, net of cash acquired	(24.8)	(290.3)	(19.9)
Additions to property	(255.3)	(190.9)	(232.5)
Proceeds from sale of property and assets held for sale	18	19.4	2.5
Proceeds from sale of business	50.5	0	0
Purchases of equity securities	0	(5)	(29.2)
Sale of equity securities	0	34.2	0
Investments in partnerships	(9)	(22.1)	0
Investment of subsidiary initial public offering proceeds into trust account	0	(345)	0
Cross-currency swap cash settlements	0	0	52.7
Other, net	0.4	7.7	10
Net Cash Used in Investing Activities - continuing operations	(220.2)	(792)	(216.4)
Net Cash Used in Investing Activities - discontinued operations	(0.8)	(1.6)	(2.1)
Net Cash Used in Investing Activities	(221)	(793.6)	(218.5)
Cash Flows from Financing Activities
Proceeds from issuance of debt	2,365	1,800	3,377.2
Repayments of debt, net of discounts	(1,563.3)	(1,698.3)	(2,932.8)
Purchases of treasury stock	(443)	(397.1)	(589.1)
Proceeds from initial public offering	0	305	0
Premium from issuance of debt	17.5	0	22
Payments of debt issuance costs, deferred financing fees and tender fees	(26.4)	(16.8)	(35.7)
Refund of debt issuance costs	0	0	15.3
Payments of debt premiums	(24.1)	(74.3)	(49.8)
Cash received from share repurchase contracts	0	47.5	0
Cash paid for share repurchase contracts	0	0	46.4
Distributions (to) from BellRing Brands, Inc., net	(547.2)	24.6	32.1
Other, net	(15.7)	(37.2)	(12.2)
Net Cash Used in Financing Activities - continuing operations	(237.2)	(46.6)	(219.4)
Net Cash Used in Financing Activities - discontinued operations	(149.5)	(120.9)	(52.6)
Net Cash Used in Financing Activities	(386.7)	(167.5)	(272)
Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	(9)	3.7	3.8
Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash	(234.1)	(369.2)	138.9
Cash, Cash Equivalents and Restricted Cash, Beginning of Year	671.6	1,144.7	1,049
Cash, Cash Equivalents and Restricted Cash from discontinued operations, Beginning of Year	152.6	48.7	5.5
Cash, Cash Equivalents and Restricted Cash from discontinued operations, End of Year	0	152.6	48.7
Cash, Cash Equivalents and Restricted Cash, End of Year	$ 590.1	$ 671.6	$ 1,144.7

Consolidated Statement of Share

Consolidated Statement of Shareholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Preferred Stock	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Retirement Benefit Adjustments, net of tax	Hedging Adjustments, net of tax	Foreign Currency Translation Adjustments	Treasury Stock	Noncontrolling Interest	Stockholders Equity, excluding Mezzanine Equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred Stock, Shares			0
Common Stock, Shares		72.1
Balance at beginning of period at Sep. 30, 2019				$ 0	$ 0.8	$ 3,734.8	$ 207.8	$ 26.6	$ 44.5	$ (167.9)	$ (920.7)	$ 11.4	$ 2,937.3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Earnings							0.8						0.8
Activity under stock and deferred compensation plans						(8.3)						0.1	(8.2)
Activity under stock and deferred compensation plans (shares)		0.4	0
Non-cash stock-based compensation expense						47.2						2.5	49.7
Purchases of treasury stock (shares)		(6.1)
Purchases of treasury stock		$ (587.8)				0					(587.8)		(587.8)
Initial public offering						455.6						(65)	390.6
Net earnings attributable to noncontrolling interest	$ 1											28.2	28.2
Cash paid for share repurchase contracts						(46.4)							(46.4)
Net change in retirement benefits, net of tax								(30.9)					(30.9)
Net change in hedges, net of tax									25.8			(2.4)	23.4
Foreign currency translation adjustments										72.6		(0.3)	72.3
Balance at the end of period at Sep. 30, 2020				0	0.8	4,182.9	208.6	(4.3)	70.3	(95.3)	(1,508.5)	(25.5)	2,829
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred Stock, Shares			0
Common Stock, Shares		66.4
Net Earnings							166.7						166.7
Post Holdings Partnering Corporation deemed dividend							(28)						(28)
Activity under stock and deferred compensation plans					0.1	(28.1)						(0.8)	(28.8)
Activity under stock and deferred compensation plans (shares)		0.7	0
Non-cash stock-based compensation expense						51.2						4.6	55.8
Purchases of treasury stock (shares)		(4)
Purchases of treasury stock		$ (393.7)				0					(393.7)		(393.7)
Net earnings attributable to noncontrolling interest	7											34.2	34.2
Cash paid for share repurchase contracts						47.5							47.5
Distribution to noncontrolling interest							0					(1)	(1)
Net change in retirement benefits, net of tax								(6.6)					(6.6)
Net change in hedges, net of tax									1.1			0.6	1.7
Foreign currency translation adjustments										77.7		(0.3)	77.4
Balance at the end of period at Sep. 30, 2021	2,754.2			0	0.9	4,253.5	347.3	(10.9)	71.4	(17.6)	(1,902.2)	11.8	2,754.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred Stock, Shares			0
Common Stock, Shares		63.1
Net Earnings							756.6						756.6
Post Holdings Partnering Corporation deemed dividend							5.1						5.1
Activity under stock and deferred compensation plans		$ 0				(14.3)						(0.9)	(15.2)
Activity under stock and deferred compensation plans (shares)		0.5	0
Non-cash stock-based compensation expense						66.5						2.9	69.4
Purchases of treasury stock (shares)		(4.9)	0
Purchases of treasury stock		$ (439)									(439)	(18.1)	(457.1)
Net earnings attributable to noncontrolling interest	7.5											12.6	12.6
Net change in retirement benefits, net of tax								(18.8)					(18.8)
Net change in hedges, net of tax									3.4			1.9	5.3
Foreign currency translation adjustments										(292.7)		(1.2)	(293.9)
BellRing Spin-Off						442.5				2.3		2.7	447.5
Balance at the end of period at Sep. 30, 2022	$ 3,265.7			$ 0	$ 0.9	$ 4,748.2	$ 1,109	$ (29.7)	$ 74.8	$ (308)	$ (2,341.2)	$ 11.7	$ 3,265.7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred Stock, Shares			0
Common Stock, Shares		58.7

Background

Background	12 Months Ended
	Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Background	BACKGROUND Post is a consumer packaged goods holding company operating in the center-of-the-store, refrigerated, foodservice and food ingredient food categories. The Company’s products are sold through a variety of channels, including grocery, club and drug stores, mass merchandisers, foodservice, food ingredient and eCommerce. As of September 30, 2022, Post operates in four reportable segments: Post Consumer Brands, Weetabix, Foodservice and Refrigerated Retail. The Post Consumer Brands segment includes the North American ready-to-eat (“RTE”) cereal and Peter Pan nut butters businesses; the Weetabix segment includes primarily the United Kingdom (the “U.K.”) RTE cereal, muesli and protein-based ready-to-drink (“RTD”) shake businesses; the Foodservice segment includes primarily egg and potato products; and the Refrigerated Retail segment includes primarily side dish, egg, cheese and sausage products. Unless otherwise stated or the context otherwise indicates, all references in these financial statements and notes to “Post,” “the Company,” “us,” “our” or “we” mean Post Holdings, Inc. and its consolidated and non-consolidated subsidiaries. On March 10, 2022, the Company completed its previously announced distribution of 80.1% of its ownership interest in BellRing Brands, Inc. (formerly known as BellRing Distribution, LLC) (“BellRing”) to Post’s shareholders (the “BellRing Distribution”, and such transaction, as well as the BellRing Contribution, the BellRing Merger (as such terms are defined in Note 4), the Debt-for-Debt Exchange (as such term is defined in Note 16) and the related transactions described in Note 4, the “BellRing Spin-off”). The BellRing Spin-off represented a strategic shift that had a major effect on the Company’s operations and consolidated financial results. Accordingly, the historical results of BellRing Intermediate Holdings, Inc. (formerly known as BellRing Brands, Inc.) (“Old BellRing”) and BellRing Distribution, LLC prior to the BellRing Spin-off have been presented as discontinued operations in the Company’s Consolidated Statements of Operations, Consolidated Balance Sheets and Consolidated Statements of Cash Flows. The Notes to Consolidated Financial Statements reflect continuing operations only, unless otherwise indicated. See Note 4 for additional information regarding the BellRing Spin-off and discontinued operations. The Company completed its acquisitions of the Egg Beaters liquid egg brand (“Egg Beaters”) and the Peter Pan nut butter brand (“Peter Pan”) on May 27, 2021 and January 25, 2021, respectively. The year-end close date for both Egg Beaters and Peter Pan was September 26, 2021. As the amounts associated with the additional four days were immaterial, results of these entities were not adjusted to conform with Post’s fiscal calendar in fiscal 2021. Certain reclassifications have been made to previously reported financial information to conform to our current period presentation.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Summary of Signifcant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Principles of Consolidation — The consolidated financial statements include the operations of Post and its consolidated subsidiaries. All intercompany transactions have been eliminated. Use of Estimates and Allocations — The consolidated financial statements of the Company are prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”), which require certain elections as to accounting policy, estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent liabilities at the dates of the financial statements and the reported amount of net revenues and expenses during the reporting periods. Significant accounting policy elections, estimates and assumptions include, among others, allowance for trade promotions, business combinations, pension and benefit plan assumptions, valuation assumptions of goodwill and other intangible assets and income taxes. Actual results could differ from those estimates. Business Combinations — The Company uses the acquisition method of accounting for acquired businesses. Under the acquisition method, the Company’s financial statements reflect the operations of an acquired business starting from the completion of the acquisition. The assets acquired and liabilities assumed are recorded at their respective estimated fair values at the date of the acquisition. Any excess of the purchase price over the estimated fair values of the identifiable net assets acquired is recorded as goodwill. Any excess of the estimated fair values of the identifiable net assets acquired over the purchase price is recorded as a gain on bargain purchase. Cash Equivalents — Cash equivalents include all highly liquid investments with original maturities of less than three months. Restricted Cash — Restricted cash includes items such as cash deposits which serve as collateral for certain commodity hedging contracts as well as the Company’s high deductible workers’ compensation insurance program. Receivables — Receivables are reported net of appropriate allowances for credit losses, cash discounts and other amounts which the Company does not ultimately expect to collect. To calculate an allowance for credit losses, the Company estimates uncollectible amounts based on a review of past due balances, historical loss information and an evaluation of customer accounts for potential future losses. A receivable is considered past due if payments have not been received within the agreed upon invoice terms. Receivables are written off against the allowance when the customer files for bankruptcy protection or are otherwise deemed to be uncollectible based upon the Company’s evaluation of the customer’s solvency. As of September 30, 2022 and 2021, the Company did not have off-balance sheet credit exposure related to its customers. The Weetabix segment sells certain receivables to a third party institution without recourse. Receivables sold during the years ended September 30, 2022 and 2021 were $111.7 and $140.2, respectively. Inventories — Inventories, other than flocks, are generally valued at the lower of average cost (determined on a first-in, first-out basis) or net realizable value. Reported amounts have been reduced by an allowance for obsolete product and packaging materials based on a review of inventories on hand compared to estimated future usage and sales. Flock inventory represents the cost of purchasing and raising chicken flocks to egg laying maturity. The costs included in our flock inventory include the costs of the chicks, the feed fed to the birds and the labor and overhead costs incurred to operate the pullet facilities until the birds are transferred into the laying facilities, at which time their cost is amortized to operations, as cost of goods sold, over their expected useful lives of one to two years. Restructuring Expenses — Restructuring charges and related charges principally consist of one-time termination benefits, severance, contract termination benefits, accelerated stock compensation and other employee separation costs. The Company recognizes restructuring obligations and liabilities for exit and disposal activities at fair value in the period the liability is incurred. Employee severance costs are expensed when they become probable and reasonably estimable under established severance plans. Property — Property is recorded at cost, and depreciation expense is generally provided on a straight-line basis over the estimated useful lives of the properties. Estimated useful lives range from 1 to 29 years for machinery and equipment; 1 to 35 years for buildings, building improvements and leasehold improvements; and 1 to 7 years for software. Total depreciation expense was $232.9, $222.2 and $206.7 in fiscal 2022, 2021 and 2020, respectively. Any gains and losses incurred on the sale or disposal of assets are included in “Other operating expense (income), net” in the Consolidated Statements of Operations. Repair and maintenance costs incurred in connection with ongoing and planned major maintenance activities are accounted for under the direct expensing method. Property consisted of: September 30, 2022 2021 Land and land improvements $ 92.2 $ 106.2 Buildings and leasehold improvements 932.7 939.4 Machinery and equipment 1,951.1 1,949.6 Software 110.6 111.4 Construction in progress 182.7 111.3 3,269.3 3,217.9 Accumulated depreciation (1,517.4) (1,387.4) $ 1,751.9 $ 1,830.5 Goodwill — Goodwill represents the excess of the purchase price of acquired businesses over the fair market value of their identifiable net assets. The Company conducts a goodwill impairment assessment during the fourth quarter of each fiscal year following the annual forecasting process, or more frequently if facts and circumstances indicate that goodwill may be impaired. The goodwill impairment assessment performed may be either qualitative or quantitative; however, if adverse qualitative trends are identified that could negatively impact the fair value of the business, a quantitative goodwill impairment test is performed. In fiscal 2022, 2021 and 2020, the Company performed a quantitative impairment test for all reporting units. The estimated fair value is determined using a combined income and market approach with a greater weighting on the income approach. The income approach is based on discounted future cash flows and requires significant assumptions, including estimates regarding future revenue, profitability, capital requirements and discount rates. The market approach is based on a market multiple (revenue and EBITDA) and requires an estimate of appropriate multiples based on market data for comparable peers. See Note 8 for additional information on goodwill and the annual goodwill impairment assessments for the years ended September 30, 2022, 2021 and 2020. These fair value measurements fall within Level 3 of the fair value hierarchy as described in Note 14. Other Intangible Assets — Other intangible assets consist primarily of customer relationships, trademarks and brands acquired in business combinations and include both indefinite and definite-lived assets. Amortization expense related to definite-lived intangible assets, which is provided on a straight-line basis over the estimated useful lives of the assets, was $146.0, $143.2 and $138.1 in fiscal 2022, 2021 and 2020, respectively. For the definite-lived intangible assets recorded as of September 30, 2022, amortization expense of $145.0, $143.9, $142.6, $142.6 and $142.6 is expected for fiscal 2023, 2024, 2025, 2026 and 2027, respectively. Other intangible assets consisted of: September 30, 2022 September 30, 2021 Carrying Accum. Net Carrying Accum. Net Subject to amortization: Customer relationships $ 2,129.7 $ (816.4) $ 1,313.3 $ 2,163.1 $ (716.4) $ 1,446.7 Trademarks and brands 647.7 (260.4) 387.3 647.9 (228.5) 419.4 2,777.4 (1,076.8) 1,700.6 2,811.0 (944.9) 1,866.1 Not subject to amortization: Trademarks and brands 1,011.6 — 1,011.6 1,058.3 — 1,058.3 $ 3,789.0 $ (1,076.8) $ 2,712.2 $ 3,869.3 $ (944.9) $ 2,924.4 In December 2021, the Company sold the Willamette Egg Farms business (the “WEF Transaction”). As a result, the Company recorded a write-off of $8.8 and $1.7 relating to customer relationships, net and trademarks, net, respectively. For additional information on the WEF Transaction, see Note 7. Recoverability of Assets — The Company continually evaluates whether events or circumstances have occurred which might impair the recoverability of the carrying value of its assets, including property, identifiable intangibles and right-of-use (“ROU”) assets. Trademarks with indefinite lives are reviewed for impairment during the fourth quarter of each fiscal year following the annual forecasting process, or more frequently if facts and circumstances indicate the trademark may be impaired. The trademark impairment test performed may either be qualitative or quantitative; however, if adverse qualitative trends are identified that could negatively impact the fair value of the trademark, a quantitative impairment test is performed. In fiscal 2022, 2021 and 2020, the Company performed a quantitative impairment test. The quantitative trademark impairment tests require the Company to compare the calculated fair value of the trademark to its carrying value. If the carrying value of the intangible asset exceeds its fair value, an impairment loss is recognized in an amount equal to that excess. The fair value is determined using an income-based approach, which requires significant assumptions for each brand, including estimates regarding future revenue growth, discount rates and royalty rates. Assumptions are determined after consideration of several factors for each brand, including profit levels, research of external royalty rates by third party experts and the relative importance of each brand to the Company. Revenue growth assumptions are based on historical trends and management’s expectations for future growth by brand. The discount rate is based on a weighted-average cost of capital utilizing industry market data of similar companies. The Company conducted impairment reviews and concluded there were no impairments of any indefinite-lived assets during the years ended September 30, 2022, 2021 or 2020. These fair value measurements fall within Level 3 of the fair value hierarchy as described in Note 14. In addition, definite-lived assets (groups) are tested for recoverability when events or changes in circumstances indicate that the carrying value of an asset (group) may not be recoverable or the estimated useful life is no longer appropriate. The Company groups assets at the lowest level for which cash flows are separately identifiable. In general, an asset (group) is deemed impaired and written down to its fair value if the estimated related undiscounted future cash flows are less than its carrying amount. There were no indicators, including adverse trends in the business, that indicated that the carrying value of the Company’s definite-lived assets (groups) were not recoverable in fiscal 2022, 2021 or 2020. Deferred Compensation Investments — The Company funds a portion of its deferred compensation liability by investing in certain mutual funds in substantially the same amounts as selected by the participating employees. Because management’s intent is to invest in a manner that matches the deferral options chosen by the participants and those participants can elect to transfer amounts into or out of each of the designated deferral options at any time, these investments are stated at fair value in “Prepaid expenses and other current assets” and “Other assets” on the Consolidated Balance Sheets (see Note 14). Both realized and unrealized gains and losses on these assets are included in “Selling, general and administrative expenses” in the Consolidated Statements of Operations and offset the related change in the deferred compensation liability. Derivative Financial Instruments — In the ordinary course of business, the Company is exposed to commodity price risks relating to the purchases of raw materials and supplies, interest rate risks relating to variable rate debt and foreign currency exchange rate risks. The Company utilizes derivative financial instruments, including (but not limited to) futures contracts, option contracts, forward contracts and swaps, to manage certain of these exposures by hedging when it is practical to do so. The Company does not hold or issue financial instruments for speculative or trading purposes. The Company’s derivative programs may include strategies that qualify and strategies that do not qualify for hedge accounting treatment. To qualify for hedge accounting, the hedging relationship, both at inception of the hedge and on an ongoing basis, is expected to be highly effective in achieving offsetting changes in the fair value of the hedged risk during the period that the hedge is designated. All derivatives are recognized on the balance sheet at fair value. For derivatives that qualify for hedge accounting, the derivative is designated as a hedge on the date in which the derivative contract is entered. A derivative could be designated as a hedge of a forecasted transaction or of the variability of cash flows to be received or paid related to a recognized asset or liability (cash flow hedge) or a hedge of a net investment in a foreign operation. Some derivatives may also be considered natural hedging instruments, where changes in their fair value act as economic offsets to changes in fair value of the underlying hedged item and are not designated for hedge accounting. Gains and losses on derivatives designated as cash flow hedges are recorded in other comprehensive income or loss (“OCI”) and are reclassified to the Consolidated Statements of Operations in conjunction with the recognition of the underlying hedged item. If a derivative is designated as a hedge of a net investment in a foreign operation, its changes in fair value are recorded in OCI and subsequently recognized in earnings when the foreign operation is liquidated. Changes in the fair value of derivatives that are not designated for hedge accounting are recognized immediately in the Consolidated Statements of Operations. Cash flows associated with all derivatives are reported as cash flows from operating activities in the Consolidated Statements of Cash Flows, unless the derivative contains an other-than-insignificant financing element, in which case its cash flows are reported as cash flows from financing activities. Leases — The Company leases office space, certain warehouses and equipment primarily through operating lease agreements. The Company has no material finance lease agreements. The Company determines if an arrangement is a lease at its inception. When the arrangements include lease and non-lease components, the Company accounts for them as a single lease component. Leases with an initial term of less than 12 months are not reported on the balance sheet, but rather are recognized as lease expense on a straight-line basis over the lease term. Arrangements may include options to extend or terminate the lease arrangement. These options are included in the lease term used to establish ROU assets and lease liabilities when it is reasonably certain they will be exercised. The Company will reassess expected lease terms based on changes in circumstances that indicate options may be more or less likely to be exercised. The Company has certain lease arrangements that include variable rental payments. The future variability of these payments and adjustments are unknown and therefore are not included in minimum rental payments used to determine ROU assets and lease liabilities. The Company has lease arrangements where it makes separate payments to the lessor based on the lessor’s common area maintenance expenses, property and casualty insurance costs, property taxes assessed on the property and other variable expenses. As the Company has elected the practical expedient not to separate lease and non-lease components, these variable amounts are captured in operating lease expense in the period in which they are incurred. Variable rental payments are recognized in the period in which their associated obligation is incurred. For lease arrangements that do not provide an implicit interest rate, an incremental borrowing rate (“IBR”) is applied in determining the present value of future payments. The Company’s IBR is selected based upon information available at the lease commencement date. ROU assets are recorded as “Other assets” and lease liabilities are recorded as “Other current liabilities” and “Other liabilities” on the Consolidated Balance Sheets. Operating lease expense is recognized on a straight-line basis over the lease term and is included in either “Cost of goods sold” or “Selling, general and administrative expenses” in the Consolidated Statements of Operations. Costs associated with finance leases and lease income do not have a material impact on the Company’s financial statements. Revenue — The Company recognizes revenue when performance obligations have been satisfied by transferring control of the goods to customers. Control is generally transferred upon delivery of the goods to the customer. At the time of delivery, the customer is invoiced using previously agreed-upon credit terms. Shipping and/or handling costs that occur before the customer obtains control of the goods are deemed fulfillment activities and are accounted for as fulfillment costs. The Company’s contracts with customers generally contain one performance obligation. Many of the Company’s contracts with customers include some form of variable consideration. The most common forms of variable consideration are trade promotions, rebates and discounts. Variable consideration is treated as a reduction of revenue at the time product revenue is recognized. Depending on the nature of the variable consideration, the Company uses either the “expected value” or the “most likely amount” method to determine variable consideration. The Company does not believe that there will be significant changes to its estimates of variable consideration when any uncertainties are resolved with customers. The Company reviews and updates estimates of variable consideration quarterly. Uncertainties related to the estimates of variable consideration are resolved in a short time frame and do not require any additional constraint on variable consideration. The Company’s products are sold with no right of return, except in the case of goods which do not meet product specifications or are damaged. No services beyond this assurance-type warranty are provided to customers. Customer remedies include either a cash refund or an exchange of the product. As a result, the right of return and related refund liability is estimated and recorded as a reduction of revenue based on historical sales return experience. Cost of Goods Sold — Cost of goods sold includes, among other things, inbound and outbound freight costs (including the Company-owned fleet) and depreciation expense related to assets used in production, while storage and other warehousing costs are included in “Selling, general and administrative expenses” in the Consolidated Statements of Operations. Storage and other warehousing costs totaled $204.0, $167.7 and $160.4 in fiscal 2022, 2021 and 2020, respectively. Advertising — Advertising costs are expensed as incurred except for costs of producing media advertising, such as television commercials or magazine and online advertisements, which are deferred until the first time the advertising takes place and amortized to the statement of operations over the time the advertising takes place. The amounts reported as assets on the Consolidated Balance Sheets as “Prepaid expenses and other current assets” were $1.4 and $1.1 as of September 30, 2022 and 2021, respectively. Stock-based Compensation — The Company recognizes the cost of employee services received in exchange for awards of equity instruments based on the grant date fair value of the equity or liability award. For liability awards, the fair market value is remeasured at each quarterly reporting period. The cost for equity and liability awards is recognized ratably over the period during which an employee is required to provide service in exchange for the award — the requisite service period (usually the vesting period). Any forfeitures of stock-based awards are recorded as they occur. See Note 19 for disclosures related to stock-based compensation. Income Taxes — Income tax expense (benefit) is estimated based on income taxes in each jurisdiction and includes the effects of both current tax exposures and the temporary differences resulting from differing treatment of items for tax and financial reporting purposes. These temporary differences result in deferred tax assets and liabilities. A valuation allowance is established against the related deferred tax assets to the extent that it is more likely than not that the future benefits will not be realized. Reserves are recorded for estimated exposures associated with the Company’s tax filing positions, which are subject to periodic audits by governmental taxing authorities. Interest incurred due to an underpayment of income taxes is classified as income tax expense. The Company considers the undistributed earnings of its foreign subsidiaries to be permanently invested, so no United States (“U.S.”) taxes have been provided in relation to the Company’s investment in its foreign subsidiaries. See Note 9 for disclosures related to income taxes. Earnings (Loss) per Share — The Company presents basic and diluted earnings (loss) per share for both continuing and discontinued operations. Basic earnings (loss) per share is based on the average number of shares of common stock outstanding during the year. Diluted earnings (loss) per share is based on the average number of shares used for the basic earnings (loss) per share calculation, adjusted for the dilutive effect of stock options, stock appreciation rights and restricted stock units using the “treasury stock” method and convertible senior notes using the “if-converted” method. Remeasurements to the redemption value of the redeemable noncontrolling interest (“NCI”) (as discussed in Note 5) are recognized as a deemed dividend. The Company has made an election to treat the portion of the deemed dividend that exceeds fair value as an adjustment to income available to common shareholders for basic and diluted earnings (loss) from continuing operations per share. In addition, dilutive net earnings from continuing operations was adjusted for interest expense, net of tax, related to the Company’s convertible senior notes, and dilutive net earnings from discontinued operations was adjusted for the Company’s share of Old BellRing’s consolidated net earnings prior to the BellRing Spin-off, to the extent it was dilutive. Net earnings (loss) from continuing operations was utilized as the “control number” to determine whether potential shares of common stock were dilutive or anti-dilutive.

Recently Issued and Adopted Acc

Recently Issued and Adopted Accounting Standards	12 Months Ended
	Sep. 30, 2022
Accounting Standards Update and Change in Accounting Principle [Abstract]
New Accounting Pronouncements and Changes in Accounting Principles	RECENTLY ISSUED AND ADOPTED ACCOUNTING STANDARDS The Company has considered all new accounting pronouncements and has concluded there are no new pronouncements (other than the ones described below) that had or will have an impact on the Company’s results of operations, comprehensive income, financial condition, cash flows, shareholders’ equity or related disclosures based on current information. In October 2021, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2021-08, “Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers.” This ASU requires a company to recognize and measure contract assets and contract liabilities acquired in a business combination in accordance with ASU No. 2014-19, “Revenue from Contracts with Customers (Topic 606)” as if it had originated the contracts. The Company early adopted this ASU as of October 1, 2021 on a prospective basis, as permitted by the ASU. The adoption of this ASU had no impact on the Company’s consolidated financial statements and related disclosures. In August 2020, the FASB issued ASU No. 2020-06, “Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity,” which simplifies the accounting for convertible instruments by removing major separation models required under current GAAP. This ASU also removes certain settlement conditions that are required for equity-linked contracts to qualify for the derivative scope exception, and it simplifies the diluted earnings per share calculation in certain areas. The Company early adopted this ASU on October 1, 2021, using the modified retrospective approach. The adoption of this ASU did not have a material impact on the Company’s consolidated financial statements and related disclosures. In March 2020 and January 2021, the FASB issued ASU No. 2020-04, “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting” and ASU No. 2021-01, “Reference Rate Reform (Topic 848): Scope,” respectively (collectively, “Topic 848”). Topic 848 provides optional expedients and exceptions for applying GAAP to contracts, hedging relationships and other transactions that reference the London Interbank Offered Rate (“LIBOR”) or another reference rate expected to be discontinued because of reference rate reform. The expedients and exceptions provided by Topic 848 are effective for all entities as of March 12, 2020 through December 31, 2022. The Company adopted Topic 848 on October 1, 2021. The adoption of Topic 848 did not have and is not expected to have a material impact on the Company’s consolidated financial statements and related disclosures.

Discontinued Operations and Dis

Discontinued Operations and Disposal Groups	12 Months Ended
	Sep. 30, 2022
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations, Disclosure	BELLRING SPIN-OFF AND DISCONTINUED OPERATIONS BellRing Spin-off On October 21, 2019, Old BellRing (the Company’s subsidiary at the time) closed its initial public offering (the “BellRing IPO”) of 39.4 million shares of its Class A common stock, $0.01 par value per share (the “Old BellRing Class A Common Stock”). As a result of the BellRing IPO and certain other transactions completed in connection with the BellRing IPO, Old BellRing became a publicly-traded company, with the Old BellRing Class A Common Stock being traded on the New York Stock Exchange (the “NYSE”) under the ticker symbol “BRBR”, and the holding company of BellRing Brands, LLC, a Delaware limited liability company (“BellRing LLC”), owning 28.8% of its non-voting membership units (the “BellRing LLC units”) with Post owning 71.2% of the BellRing LLC units and one share of Old BellRing’s Class B common stock, $0.01 par value per share (the “Old BellRing Class B Common Stock”). The Company’s ownership of the BellRing LLC units and the share of Old BellRing Class B Common Stock resulted in the Company having a controlling interest in Old BellRing following the BellRing IPO. This controlling interest resulted in the full consolidation of Old BellRing and its subsidiaries into the Company’s financial statements prior to the BellRing Spin-off, while the remaining interest in Old BellRing’s consolidated net income and net assets not held by the Company were allocated to NCI prior to the BellRing Spin-off. On March 9, 2022, pursuant to the Transaction Agreement and Plan of Merger, dated as of October 26, 2021 (as amended by Amendment No.1 to the Transaction Agreement and Plan of Merger, dated as of February 28, 2022, the “Spin-off Agreement”), by and among Post, Old BellRing, BellRing and BellRing Merger Sub Corporation, a wholly-owned subsidiary of BellRing (“BellRing Merger Sub”), Post contributed its share of Old BellRing Class B Common Stock, all of its BellRing LLC units and $550.4 of cash to BellRing in exchange for certain limited liability company interests of BellRing and the right to receive $840.0 in aggregate principal amount of BellRing’s 7.00% senior notes maturing in 2030 (the “BellRing Notes” and such transactions, collectively, the “BellRing Contribution”). On March 10, 2022, BellRing converted into a Delaware corporation and changed its name to “BellRing Brands, Inc.”, and Post consummated the BellRing Distribution, distributing an aggregate of 78.1 million, or 80.1%, of its shares of BellRing common stock, $0.01 par value per share (“BellRing Common Stock”), to Post shareholders of record as of the close of business, Central Time, on February 25, 2022 (the “Record Date”) in a pro-rata distribution. Post shareholders received 1.267788 shares of BellRing Common Stock for every one share of Post common stock held as of the Record Date. No fractional shares of BellRing Common Stock were issued, and instead, cash in lieu of any fractional shares was paid to Post shareholders. Upon completion of the BellRing Distribution, BellRing Merger Sub merged with and into Old BellRing (the “BellRing Merger”), with Old BellRing continuing as the surviving corporation and becoming a wholly-owned subsidiary of BellRing. Pursuant to the BellRing Merger, each outstanding share of Old BellRing Class A Common Stock was converted into one share of BellRing Common Stock plus $2.97 in cash. Immediately following the BellRing Spin-off, Post owned approximately 14.2% of the BellRing Common Stock and Post shareholders owned approximately 57.3% of the BellRing Common Stock. The former Old BellRing stockholders owned approximately 28.5% of the BellRing Common Stock, maintaining the same effective percentage ownership interest in the Old BellRing business as prior to the BellRing Spin-off. As a result of the BellRing Spin-off, the dual class voting structure in the BellRing business was eliminated. The BellRing Distribution was structured in a manner intended to qualify as a tax-free distribution to Post shareholders for U.S. federal income tax purposes, except to the extent of any cash received in lieu of fractional shares of BellRing Common Stock. The Company incurred separation-related expenses related to the BellRing Spin-off and subsequent partial divestment of its Investment in BellRing (as defined below) (see Note 5) of $29.9 during the year ended September 30, 2022. The Company incurred separation-related expenses related to the BellRing Spin-off of $1.6 during the year ended September 30, 2021. These expenses were included in “Selling, general and administrative expenses” within continuing operations in the Consolidated Statements of Operations. Old BellRing incurred separation-related expenses prior to the BellRing Spin-off of $4.3 and $0.2 during the years ended September 30, 2022 and 2021, respectively, which were included in “Net earnings from discontinued operations, net of tax and noncontrolling interest” in the Consolidated Statements of Operations. These expenses generally included third party costs for advisory services, fees charged by other service providers and government filing fees. On March 17, 2022, the Company utilized proceeds received in connection with the BellRing Spin-off to redeem a portion of Post’s existing 5.75% senior notes (see Note 16). The following is a summary of BellRing’s assets and liabilities as of March 10, 2022. March 10, 2022 Assets Cash and cash equivalents (a) $ 50.6 Receivables, net 120.0 Inventories 146.1 Prepaid expenses and other current assets 17.0 Property, net 8.7 Goodwill 65.9 Other intangible assets, net 214.4 Other assets 10.3 Total Assets 633.0 Liabilities Current portion of long-term debt — Accounts payable 69.5 Other current liabilities 40.5 Long-term debt 938.8 Deferred income taxes (b) 6.3 Other liabilities 9.5 Total Liabilities 1,064.6 BellRing Net Assets $ (431.6) (a) Excludes $115.5 of merger consideration paid to former Old BellRing stockholders immediately following the completion of the BellRing Distribution. (b) Excludes $127.1 related to Post’s investment in BellRing Brands, LLC, which was contributed to BellRing and subsequently eliminated immediately following the completion of the BellRing Distribution. As a result of the BellRing Spin-off, the Company recorded a $442.5 adjustment to additional paid-in capital, which included BellRing net assets of $(431.6). The BellRing Spin-off also resulted in a reduction of accumulated OCI associated with BellRing’s foreign currency translation adjustments. The total adjustment to accumulated OCI was $2.3. The Company’s equity interest in BellRing subsequent to the BellRing Spin-off (its “Investment in BellRing”), which was 14.2% immediately following the BellRing Spin-off, did not represent a controlling interest in BellRing. As such, the Company’s remaining proportionate share of BellRing’s net assets were recorded at a zero carrying value on March 10, 2022, as the BellRing net assets were negative. See Note 5 for additional information regarding the subsequent sale of a portion of the Company’s Investment in BellRing. See Note 14 for additional information regarding the Company’s remeasurement of its Investment in BellRing to fair value at September 30, 2022. Discontinued Operations The BellRing Spin-off represented a strategic shift that had a major effect on the Company’s operations and consolidated financial results. Accordingly, the historical results of Old BellRing and BellRing Distribution, LLC prior to the BellRing Spin-off have been presented as discontinued operations in the Company’s Consolidated Statements of Operations, Consolidated Balance Sheets and Consolidated Statements of Cash Flows. The following table presents the components of net earnings from discontinued operations. The year ended September 30, 2022 represents the period ending March 10, 2022, the completion date of the BellRing Spin-off. Year Ended September 30, 2022 2021 2020 Net Sales $ 541.9 $ 1,246.0 $ 987.7 Cost of goods sold 390.3 859.8 649.7 Gross Profit 151.6 386.2 338.0 Selling, general and administrative expenses 68.5 167.1 151.8 Amortization of intangible assets 8.7 51.2 22.2 Other operating income, net — (0.1) — Operating Profit 74.4 168.0 164.0 Interest expense, net 13.1 43.2 54.7 Loss on extinguishment and refinancing of debt, net 17.6 1.6 — Earnings from Discontinued Operations before Income Taxes 43.7 123.2 109.3 Income tax expense 10.3 28.4 24.8 Net Earnings from Discontinued Operations, Including Noncontrolling Interest 33.4 94.8 84.5 Less: Net earnings attributable to noncontrolling interest from discontinued operations 11.8 33.0 27.2 Net Earnings from Discontinued Operations, net of tax and noncontrolling interest $ 21.6 $ 61.8 $ 57.3 The following table presents the carrying amounts of major classes of assets and liabilities that were included in discontinued operations at September 30, 2021. There were no assets or liabilities classified as discontinued operations at September 30, 2022. September 30, 2021 Cash and cash equivalents $ 152.6 Receivables, net 101.5 Inventories 117.9 Prepaid expenses and other current assets 13.7 Current assets of discontinued operations $ 385.7 Property, net $ 8.9 Goodwill 65.9 Other intangible assets, net 223.1 Other assets 10.5 Other assets of discontinued operations $ 308.4 Current portion of long-term debt $ 116.3 Accounts payable 89.5 Other current liabilities 43.1 Current liabilities of discontinued operations $ 248.9 Long-term debt $ 481.2 Deferred income taxes 134.8 Other liabilities 11.7 Other liabilities of discontinued operations $ 627.7

Noncontrolling Interests, Equit

Noncontrolling Interests, Equity Interests and Related Party Transactions	12 Months Ended
	Sep. 30, 2022
Equity Method Investments and Joint Ventures [Abstract]
Noncontrolling Interests, Equity Interests and Related Party Transactions	NONCONTROLLING INTERESTS, EQUITY INTERESTS AND RELATED PARTY TRANSACTIONS Post Holdings Partnering Corporation In May and June of 2021, the Company and Post Holdings Partnering Corporation, a special purpose acquisition company (“PHPC”), consummated the initial public offering of 34.5 million units of PHPC (the “PHPC Units” and such transaction, the “PHPC IPO”), of which PHPC Sponsor, LLC, our wholly-owned subsidiary (“PHPC Sponsor”), purchased 4.0 million PHPC Units. Each PHPC Unit consists of one share of Series A common stock of PHPC, $0.0001 par value per share (“PHPC Series A Common Stock”), and one-third of one redeemable warrant of PHPC, each whole warrant entitling the holder thereof to purchase one share of PHPC Series A Common Stock at an exercise price of $11.50 per share (the “PHPC Warrants”). The PHPC Units were sold at a price of $10.00 per PHPC Unit, generating gross proceeds to PHPC of $345.0. The PHPC Units, PHPC Series A Common Stock and PHPC Warrants each trade on the NYSE under the ticker symbols “PSPC.U”, “PSPC” and “PSPC WS”, respectively. Under the terms of the PHPC IPO, PHPC is required to consummate a partnering transaction by May 28, 2023 (which may be extended to August 28, 2023 in certain circumstances). Substantially concurrently with the closing of the PHPC IPO, PHPC completed the private sale of 1.1 million units of PHPC (the “PHPC Private Placement Units”), at a purchase price of $10.00 per PHPC Private Placement Unit, to PHPC Sponsor, generating proceeds to PHPC of $10.9 (the “PHPC Private Placement”). The PHPC Private Placement Units sold in the PHPC Private Placement are identical to the PHPC Units sold in the PHPC IPO, except that, with respect to the warrants underlying the PHPC Private Placement Units (the “PHPC Private Placement Warrants”) that are held by PHPC Sponsor or its permitted transferees, such PHPC Private Placement Warrants (i) may be exercised for cash or on a cashless basis, (ii) are not subject to being called for redemption (except in certain circumstances when the PHPC Warrants are called for redemption and a certain price per share of PHPC Series A Common Stock threshold is met) and (iii) subject to certain limited exceptions, will be subject to transfer restrictions until 30 days following the consummation of PHPC’s partnering transaction. If the PHPC Private Placement Warrants are held by holders other than PHPC Sponsor or its permitted transferees, the PHPC Private Placement Warrants will be redeemable by PHPC in all redemption scenarios and exercisable by holders on the same basis as the PHPC Warrants. In addition, the Company, through PHPC Sponsor’s ownership of 8.6 million shares of Series F common stock of PHPC, $0.0001 par value per share, has certain governance rights in PHPC relating to the election of PHPC directors and voting rights on amendments to PHPC’s certificate of incorporation. In connection with the completion of the PHPC IPO, PHPC also entered into a forward purchase agreement with PHPC Sponsor (the “Forward Purchase Agreement”), providing for the purchase by PHPC Sponsor, at the election of PHPC, of up to 10.0 million units of PHPC (the “PHPC Forward Purchase Units”), subject to the terms and conditions of the Forward Purchase Agreement, with each PHPC Forward Purchase Unit consisting of one share of PHPC’s Series B common stock, $0.0001 par value per share, and one-third of one warrant to purchase one share of PHPC Series A Common Stock, for a purchase price of $10.00 per PHPC Forward Purchase Unit, in an aggregate amount of up to $100.0 in a private placement to occur concurrently with the closing of PHPC’s partnering transaction. In determining the accounting treatment of the Company’s equity interest in PHPC, management concluded that PHPC is a variable interest entity (“VIE”) as defined by Accounting Standards Codification (“ASC”) Topic 810, “Consolidation.” A VIE is an entity in which equity investors at risk lack the characteristics of a controlling financial interest. VIEs are consolidated by the primary beneficiary, the party who has both the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance, as well as the obligation to absorb losses of the entity or the right to receive benefits from the VIE that could potentially be significant to the VIE. PHPC Sponsor is the primary beneficiary of PHPC as it has, through its equity interest, the right to receive benefits or the obligation to absorb losses from PHPC, as well as the power to direct a majority of the activities that significantly impact PHPC’s economic performance, including target identification. As such, PHPC is fully consolidated into the Company’s financial statements. Pr oceeds of $345.0 were deposited in a trust account established for the benefit of PHPC’s public stockholders consisting of certain proceeds from the PHPC IPO and certain proceeds from the PHPC Private Placement, net of underwriters’ discounts and commissions and other costs and expenses. A minimum balance of $345.0, representing the number of PHPC Units sold at the offering price of $10.00 per PHPC Unit , is required by the underwriting agreement to be maintained in the trust account. These pr oceeds will be invested only in U.S. treasury securities. At September 30, 2022, there was $346.8 held in the trust account, which was included in “Current investments held in trust” on the Consolidated Balance Sheet as the period in which PHPC has to complete a partnering transaction was less than twelve months as of September 30, 2022. At September 30, 2021, there was $345.0 held in the trust account, which was included in “Investments held in trust” on the Consolidated Balance Sheet as the period in which PHPC had to complete a partnering transaction was greater than twelve months as of September 30, 2021. The public stockholders’ ownership of PHPC equity represents a NCI to the Company, which is classified outside of permanent shareholders’ equity as the PHPC Series A Common Stock is redeemable at the option of the public stockholders in certain circumstances. The carrying amount of the redeemable NCI is equal to the greater of (i) the initial carrying amount, increased or decreased for the redeemable NCI’s share of PHPC’s net earnings or loss, OCI and distributions or (ii) the redemption value. The public stockholders of PHPC Series A Common Stock will be entitled in certain circumstances to redeem their shares of PHPC Series A Common Stock for a pro rata portion of the amount in the trust account at $10.00 per share of PHPC Series A Common Stock held, plus any pro rata interest earned on the funds held in the trust account and not previously released to PHPC to pay taxes. As of September 30, 2022 and 2021, the carrying amount of the redeemable NCI was recorded at its redemption value of $306.6 and $305.0, respectively. Remeasurements to the redemption value of the redeemable NCI are recognized as a deemed dividend and are recorded to “Retained earnings” on the Consolidated Balance Sheets. In connection with the PHPC IPO, PHPC incurred offering costs of $17.9, of which $16.9 was recorded to the redeemable NCI and $1.0 was reported in “Selling, general and administrative expenses” in the Consolidated Statement of Operations for the year ended September 30, 2021. Of the $17.9 offering costs incurred, $10.7 were deferred underwriting commissions that will become payable to the underwriters solely in the event that PHPC completes a partnering transaction and were included in “Other current liabilities” and “Other liabilities” on the Consolidated Balance Sheets at September 30, 2022 and 2021, respectively. Additionally, the initial valuation of the PHPC Warrants of $16.9 was recorded to redeemable NCI for the year ended September 30, 2021. For additional information on the financial statement impacts of the PHPC Warrants, see Notes 13 and 14. As of both September 30, 2022 and 2021, the Company beneficially owned 31.0% of the equity of PHPC and the net earnings and net assets of PHPC were consolidated within the Company’s financial statements. The remaining 69.0% of the consolidated net earnings and net assets of PHPC, representing the percentage of economic interest in PHPC held by the public stockholders of PHPC through their ownership of PHPC equity, were allocated to redeemable NCI. All transactions between PHPC and PHPC Sponsor, as well as related financial statement impacts, eliminate in consolidation. The following table summarizes the effects of changes in the Company’s redeemable NCI on the Company’s equity. The period for the year ended September 30, 2021 represents the period beginning May 28, 2021, the effective date of the PHPC IPO, and ending September 30, 2021. Year Ended September 30, 2022 2021 PHPC IPO offering costs $ — $ (16.9) Initial valuation of PHPC Warrants — (16.9) Net earnings attributable to redeemable NCI 6.7 5.8 Redemption value adjustment (1.6) — PHPC deemed dividend $ 5.1 $ (28.0) The following table summarizes the changes to the Company’s redeemable NCI. The period as of and for the year ended September 30, 2021 represents the period beginning May 28, 2021, the effective date of the PHPC IPO, and ending September 30, 2021. As Of and For the Year Ended September 30, 2022 2021 Balance, beginning of year $ 305.0 $ — Impact of PHPC IPO (a) — 271.2 Net earnings attributable to redeemable NCI 6.7 5.8 PHPC deemed dividend (5.1) 28.0 Balance, end of year $ 306.6 $ 305.0 (a) For the year ended September 30, 2021, the impact of the PHPC IPO includes the value of PHPC Units owned by public stockholders of $305.0 less offering costs of $16.9 and the initial valuation of PHPC Warrants of $16.9. 8th Avenue The Company has a 60.5% common equity interest in 8th Avenue that is accounted for using the equity method. In determining the accounting treatment of the common equity interest, management concluded that 8th Avenue was not a VIE as defined by ASC Topic 810, and as such, 8th Avenue was evaluated under the voting interest model. Based on the terms of 8th Avenue’s governing documents, management determined that the Company does not have a controlling voting interest in 8th Avenue due to substantive participating rights held by third parties associated with the governance of 8th Avenue. However, the Company does retain significant influence, and therefore, the use of the equity method of accounting is required. The following table presents the calculation of the Company’s equity method loss attributable to 8th Avenue. For the year ended September 30, 2022, 8th Avenue’s equity method loss attributable to Post exceeded the Company’s remaining investment in 8th Avenue. In accordance with ASC Topic 323, “Investments—Equity Method and Joint Ventures”, the Company did not recognize equity method losses in excess of its remaining investment in 8th Avenue, which was $66.6 as of September 30, 2021. As of September 30, 2022, the Company’s investment in 8th Avenue was zero. Year Ended September 30, 2021 2020 Net loss attributable to 8th Avenue common shareholders $ (60.6) $ (38.9) 60.5 % 60.5 % Equity method loss attributable to Post $ (36.7) $ (23.5) Less: Amortization of basis difference, net of tax (a) 6.8 6.9 Equity method loss, net of tax $ (43.5) $ (30.4) (a) The Company adjusted the historical basis of 8th Avenue’s assets and liabilities to fair value and recognized a basis difference of $70.3 upon the initial recording of its equity method investment in 8th Avenue. The basis difference related to property, plant and equipment and other intangible assets was initially amortized over the weighted-average useful lives of the assets. During the year ended September 30, 2022, the carrying value of the Company’s investment in 8th Avenue was reduced to zero, resulting in the termination of basis difference amortization in accordance with ASC Topic 323. At September 30, 2021, the remaining basis difference to be amortized was $47.8 . Summarized financial information of 8th Avenue is presented in the following tables. Year Ended September 30, 2022 2021 2020 Net sales $ 1,089.0 $ 900.8 $ 924.2 Gross profit $ 159.9 $ 132.3 $ 160.0 Net loss $ (210.9) $ (24.3) $ (6.4) Less: Preferred stock dividend 40.4 36.3 32.5 Net loss attributable to 8th Avenue common shareholders $ (251.3) $ (60.6) $ (38.9) September 30, 2022 2021 Current assets $ 337.0 $ 282.8 Other assets 746.6 903.0 Total Assets $ 1,083.6 $ 1,185.8 Current portion of long-term debt $ 6.5 $ 6.5 Accounts payable and other current liabilities 166.3 131.7 Long-term debt 862.4 780.0 Other liabilities 54.1 63.0 Total Liabilities 1,089.3 981.2 Preferred stock 138.3 97.9 Other shareholders’ (deficit) equity (144.0) 106.7 Shareholders’ (Deficit) Equity (5.7) 204.6 Total Liabilities and Shareholders’ Equity $ 1,083.6 $ 1,185.8 The Company provides services to 8th Avenue under a master services agreement (the “MSA”), as well as certain advisory services for a fee. During the years ended September 30, 2022, 2021 and 2020, the Company recorded MSA and advisory income of $3.2, $3.5 and $3.9, respectively, which were recorded in “Selling, general and administrative expenses” in the Consolidated Statements of Operations. During the years ended September 30, 2022, 2021 and 2020, the Company had net sales to 8th Avenue of $8.1, $6.7 and $5.7, respectively, and purchases from and royalties paid to 8th Avenue of $102.9, $54.1 and $9.9 respectively. Sales and purchases between the Company and 8th Avenue were all made at arm’s-length. The investment in 8th Avenue was zero and $66.6 at September 30, 2022 and 2021, respectively, and was included in “Equity method investments” on the Consolidated Balance Sheets. The Company had current receivables, current payables and a long-term liability with 8th Avenue of $4.4, $26.1 and $0.7, respectively, at September 30, 2022, and current receivables, current payables and a long-term liability of $4.6, $1.2 and $0.7, respectively, at September 30, 2021. The current receivables, current payables and long-term liability were included in “Receivables, net,” “Accounts payable” and “Other liabilities,” respectively, on the Consolidated Balance Sheets and related to the separation of 8th Avenue from the Company, MSA fees, pass through charges owed by 8th Avenue to the Company and related party sales and purchases. Investment in BellRing During the period subsequent to the BellRing Spin-off, the Company’s Investment in BellRing did not represent a controlling interest in BellRing and was accounted for as an equity security. The Company’s Investment in BellRing represented 19.4 million shares of BellRing Common Stock, or 14.2% of the equity interest in BellRing, immediately following the BellRing Spin-off. On August 11, 2022, the Company transferred 14.8 million shares of its Investment in BellRing to repay certain outstanding debt obligations as part of a Debt-for-Equity Exchange (as defined in Note 16). See Note 16 for additional information regarding the Debt-for-Equity Exchange. The Company’s remaining Investment in BellRing as of September 30, 2022 represented 4.6 million shares of BellRing Common Stock, or 3.4% of the outstanding equity of BellRing. As of September 30, 2022, the Company’s Investment in BellRing was recorded at its fair value of $94.8, and was included in “Investment in BellRing” on the Consolidated Balance Sheet (see Note 14). The Company recognized a gain on its Investment in BellRing of $437.1 during the year ended September 30, 2022, which was recorded in “Gain on investment in BellRing” in the Consolidated Statement of Operations. No deferred income taxes have been recorded with respect to the non-cash mark-to-market adjustment on the Company’s Investment in BellRing as of September 30, 2022, as the Company expects to fully divest, and has already partially divested through a Debt-for-Equity Exchange, its remaining Investment in BellRing within 12 months of the BellRing Spin-off in a manner intended to qualify as tax-free for U.S. federal income tax purposes. Weetabix East Africa and Alpen The Company holds a controlling equity interest in Weetabix East Africa Limited (“Weetabix East Africa”). Weetabix East Africa is a Kenyan-based company that produces RTE cereal and muesli. The Company owns 50.1% of Weetabix East Africa and holds a controlling voting and financial interest through its appointment of management and representation on Weetabix East Africa’s board of directors. Accordingly, Weetabix East Africa is fully consolidated into the Company’s financial statements and its assets and results from operations are reported in the Weetabix segment (see Note 21). The remaining interest in the consolidated net earnings and net assets of Weetabix East Africa is allocated to NCI. The Company holds an equity interest in Alpen Food Company South Africa (Pty) Limited (“Alpen”). Alpen is a South African-based company that produces RTE cereal and muesli. The Company owns 50% of Alpen’s common stock with no other indicators of control and, accordingly, the Company accounts for its investment in Alpen using the equity method. The Company’s equity method loss, net of tax, attributable to Alpen was $0.5, $0.4 and $0.5 for the years ended September 30, 2022, 2021 and 2020, respectively, and was included in “Equity method loss, net of tax” in the Consolidated Statements of Operations. The investment in Alpen was $4.1 at both September 30, 2022 and 2021 and was included in “Equity method investments” on the Consolidated Balance Sheets. The Company had a note receivable balance with Alpen of $0.4 and $0.5 at September 30, 2022 and 2021, respectively, which was included in “Other assets” on the Consolidated Balance Sheets.

Business Combinations

Business Combinations	12 Months Ended
	Sep. 30, 2022
Business Combinations [Abstract]
Business Combinations	BUSINESS COMBINATIONS Fiscal 2022 On April 5, 2022, the Company completed its acquisition of Lacka Foods Limited (“Lacka Foods”), a U.K.-based distributor and marketer of ready-to-drink protein shakes and nutritional snacks, for £24.5 million (approximately $32.2), net of cash acquired. The acquisition included earnings-based contingent consideration of £3.5 million (approximately $4.6), representing its initial fair value estimate, which may be paid to the seller in annual installments over the next three years with a maximum cash payout of £3.5 million. The acquisition was completed using cash on hand. Lacka Foods is reported in the Weetabix segment (see Note 21). Based upon the purchase price allocation, the Company identified and recorded net assets of $32.9, including cash acquired of $0.7. The net assets acquired included customer relationships and trademarks of $11.8 and $8.9, respectively, which are each being amortized over a weighted-average period of 13 years. Fiscal 2021 On June 1, 2021, the Company completed its acquisition of the private label RTE cereal business from TreeHouse Foods, Inc. (the “PL RTE Cereal Business”) for $85.0, subject to inventory and other adjustments, resulting in a payment at closing of $88.0. The acquisition was completed using cash on hand. The PL RTE Cereal Business is reported in the Post Consumer Brands segment (see Note 21). Based on the purchase price allocation at September 30, 2021, the Company identified and recorded $99.5 of net assets, which exceeded the purchase price paid for the PL RTE Cereal Business. As a result, the Company recorded a gain of $ 11.5 On May 27, 2021, the Company completed its acquisition of Egg Beaters from Conagra Brands, Inc. for $50.0, subject to working capital and other adjustments, resulting in a payment at closing of $50.6. The acquisition was completed using cash on hand. Egg Beaters is a retail liquid egg brand and is reported in the Refrigerated Retail segment (see Note 21). On February 1, 2021, the Company completed its acquisition of the Almark Foods business and related assets (“Almark”) for $52.0, subject to working capital and other adjustments, resulting in a payment at closing of $51.3. The acquisition was completed using cash on hand. Almark is a provider of hard-cooked and deviled egg products, offering conventional, organic and cage-free products, and distributes its products to foodservice distributors, as well as across retail outlets, including in the perimeter-of-the-store and the deli counter. Almark is reported in the Foodservice and Refrigerated Retail segments (see Note 21). At September 30, 2021, the Company had recorded an estimated working capital receivable of $3.0, which was included in “Receivables, net” on the Consolidated Balance Sheet. During the year ended September 30, 2022, the Company recorded a final measurement period adjustment and a working capital adjustment of $0.3 and $1.3, respectively, and reached a final net working capital settlement, resulting in an amount received by the Company of $2.9. As a result of the final net working capital settlement, the Company recorded a gain of $1.2, which was included in “Other operating expense (income), net” in the Consolidated Statement of Operations for the year ended September 30, 2022. On January 25, 2021, the Company completed its acquisition of Peter Pan from Conagra Brands, Inc. for $102.0, subject to working capital and other adjustments, resulting in a payment at closing of $103.4. The acquisition was completed using cash on hand. Peter Pan is a nationally recognized brand with a diversified customer base across key channels and is reported in the Post Consumer Brands segment (see Note 21). All Peter Pan nut butter products are currently co-manufactured by 8th Avenue, in which the Company has a 60.5% common equity interest (see Note 5). In April 2021, the Company reached a final settlement of net working capital, resulting in an amount received by the Company of $2.0. Fiscal 2020 On July 1, 2020, the Company completed its acquisition of Henningsen Foods, Inc. (“Henningsen”) from a subsidiary of Kewpie Corporation for $20.0, subject to working capital and other adjustments, resulting in a payment at closing of $22.7. The acquisition was completed using cash on hand. Henningsen is a producer of egg and meat products and is reported in the Foodservice segment (see Note 21). Based upon the purchase price allocation at September 30, 2020, the Company identified and recorded $32.6 of net assets, including cash of $2.8, which exceeded the purchase price paid for Henningsen. As a result, the Company recorded a gain of $ 11.7 Acquisition-Related Expenses The Company incurs transaction-related expenses in conjunction with both completed and contemplated acquisitions. These expenses generally include third party costs for due diligence, advisory services and transaction success fees. During the years ended September 30, 2022, 2021 and 2020, the Company incurred transaction-related expenses of $3.2, $6.4 and $3.8, respectively, which were recorded in “Selling, general and administrative expenses” in the Consolidated Statements of Operations. Unaudited Pro Forma Information The following unaudited pro forma information presents a summary of the combined results of operations of the Company and the results of the fiscal 2021 acquisitions for the periods presented as if these acquisitions had occurred on October 1, 2019, along with certain pro forma adjustments. The results of operations for the fiscal 2022 and 2020 acquisitions were immaterial for presentation within the following unaudited pro forma information. These pro forma adjustments give effect to the amortization of certain definite-lived intangible assets, adjusted depreciation based upon fair value of assets acquired, inventory revaluation adjustments on acquired businesses, interest expense, transaction costs, gain on bargain purchase and related income taxes. The following unaudited pro forma information has been prepared for comparative purposes only and is not necessarily indicative of the results of operations as they would have been had the acquisition occurred on the assumed date, nor is it necessarily an indication of future operating results. Pro forma adjustments related to the fiscal 2021 acquisitions did not affect results of operations for the year ended September 30, 2022. Year Ended September 30, 2021 2020 Pro forma net sales $ 5,184.3 $ 5,182.0 Pro forma net earnings (loss) from continuing operations available to common shareholders $ 96.9 $ (42.2) Pro forma basic earnings (loss) from continuing operations per common share $ 1.51 $ (0.61) Pro forma diluted earnings (loss) from continuing operations per common share $ 1.48 $ (0.61)

Divestitures and Amounts Held F

Divestitures and Amounts Held For Sale	12 Months Ended
	Sep. 30, 2022
Assets and Liabilities Held for Sale [Abstract]
Divestitures and Amounts Held For Sale	DIVESTITURES AND AMOUNTS HELD FOR SALE Divestiture On December 1, 2021, the Company completed the WEF Transaction, which included the sale of $62.8 book value of assets, for total proceeds of $56.1. Of the $56.1, the Company had $6.0 in escrow, subject to certain contingencies, which was included in “Receivables, net” on the Consolidated Balance Sheet at September 30, 2022. As a result of the WEF Transaction, during the year ended September 30, 2022, the Company recorded a net loss on sale of business of $6.3, which included a favorable working capital adjustment of $0.4, and was reported as “Other operating expense (income), net” in the Consolidated Statement of Operations. Subsequent to the WEF Transaction, Willamette Egg Farms was no longer consolidated in the Company’s financial statements. Prior to the WEF Transaction, Willamette Egg Farms’ operating results were reported in the Refrigerated Retail segment (see Note 21). Amounts Held For Sale The Company had certain Foodservice production equipment in Klingerstown, Pennsylvania (the “Klingerstown Equipment”) and Jefferson City, Tennessee (the “Jefferson City Equipment”) classified as held for sale. The Company sold the Klingerstown Equipment in November 2021 and entered into an agreement to sell the Jefferson City Equipment in August 2022, which is expected to close in fiscal 2023. In the year ended September 30, 2022, a net gain on assets held for sale of $ 9.4 9.8 0.4 In the year ended September 30, 2021, a net gain on assets held for sale of $ 0.5 0.7 0.1 0.1 In the year ended September 30, 2020, a loss on assets held for sale of $ 2.7 2.6 0.1 The above held for sale gains and losses were included in “Other operating expense (income), net” in the Consolidated Statements of Operations for the years ended September 30, 2022, 2021 and 2020.

Goodwill

Goodwill	12 Months Ended
	Sep. 30, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	GOODWILL The changes in the carrying amount of goodwill by segment are noted in the following table. Post Consumer Brands Weetabix Foodservice Refrigerated Retail Total Balance, September 30, 2020 Goodwill (gross) $ 2,011.8 $ 889.5 $ 1,335.6 $ 793.6 $ 5,030.5 Accumulated impairment losses (609.1) — — (48.7) (657.8) Goodwill (net) $ 1,402.7 $ 889.5 $ 1,335.6 $ 744.9 $ 4,372.7 Goodwill acquired 55.1 — 19.4 14.3 88.8 Currency translation adjustment 0.2 39.9 — — 40.1 Balance, September 30, 2021 Goodwill (gross) $ 2,067.1 $ 929.4 $ 1,355.0 $ 807.9 $ 5,159.4 Accumulated impairment losses (609.1) — — (48.7) (657.8) Goodwill (net) $ 1,458.0 $ 929.4 $ 1,355.0 $ 759.2 $ 4,501.6 Goodwill acquired (a) — 13.9 0.3 — 14.2 Sale of business (b) — — — (4.2) (4.2) Currency translation adjustment (0.3) (161.7) — — (162.0) Balance, September 30, 2022 Goodwill (gross) $ 2,066.8 $ 781.6 $ 1,355.3 $ 803.7 $ 5,007.4 Accumulated impairment losses (609.1) — — (48.7) (657.8) Goodwill (net) $ 1,457.7 $ 781.6 $ 1,355.3 $ 755.0 $ 4,349.6 (a) In April 2022, the Company recorded $13.9 of goodwill related to its acquisition of Lacka Foods, and in January 2022, the Company recorded a final measurement period adjustment of $0.3 related to the Almark acquisition. For additional information on the Company’s acquisitions, see Note 6. (b) In December 2021, the Company completed the WEF Transaction. For additional information on the WEF Transaction, see Note 7. The Company did not record a goodwill impairment charge during the years ended September 30, 2022, 2021 or 2020, as all reporting units subjected to the quantitative test passed during each year. At September 30, 2022, the Cheese and Dairy reporting unit and the Refrigerated Retail reporting unit fair values exceeded their carrying values by approximately 6.5% and 8.5%, respectively. At September 30, 2022, the estimated fair values of all other reporting units exceeded their carrying values by at least 10%. At September 30, 2021, the estimated fair values of all such reporting units exceeded their carrying values by at least 11% (the lowest of which was Foodservice; all others exceeded their carrying values by at least 15%). At September 30, 2020, the estimated fair values of all such reporting units exceeded their carrying values by at least 4% (the lowest of which was Foodservice; all others exceeded their carrying values by at least 13%). The fair values of the Cheese and Dairy and Refrigerated Retail reporting units at September 30, 2022 were impacted by raw material cost inflation and supply constraints, which impacted near-term profitability. The Company expects these impacts to be transitory in nature; however, inherent risk to their respective cash flows remains. Variances between the actual performance of the businesses and the assumptions that were used in developing the estimates of fair value could result in impairment charges in future periods. Factors that could create variances in the estimated fair value of the reporting units include but are not limited to (i) fluctuations in forecasted sales volumes, which can be driven by external factors affecting demand such as changes in consumer preferences and consumer responses to marketing and pricing strategy, (ii) changes in product costs, including commodities, (iii) a significant change in profitability, (iv) interest rate fluctuations and (v) currency fluctuations.

Income Taxes

Income Taxes	12 Months Ended
	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Income taxes	INCOME TAXES The components of “Earnings (Loss) before Income Taxes and Equity Method Loss” on the Consolidated Statements of Operations and other summary information is presented in the following table. Year Ended September 30, 2022 2021 2020 Domestic $ 799.9 $ 105.9 $ (146.5) Foreign 95.4 108.1 100.6 Earnings (Loss) before Income Taxes and Equity Method Loss $ 895.3 $ 214.0 $ (45.9) Income tax expense (benefit) $ 85.7 $ 58.2 $ (21.3) Effective income tax rate 9.6 % 27.2 % (46.4) % Income tax expense (benefit) consisted of the following: Year Ended September 30, 2022 2021 2020 Current: Federal $ 71.1 $ (20.3) $ 9.2 State 11.1 (0.2) 4.6 Foreign 13.2 10.5 9.0 95.4 (10.0) 22.8 Deferred: Federal (9.7) 22.6 (45.9) State — 3.4 (14.6) Foreign — 42.2 16.4 (9.7) 68.2 (44.1) Income tax expense (benefit) $ 85.7 $ 58.2 $ (21.3) A reconciliation of income tax expense (benefit) with amounts computed at the statutory federal rate follows: Year Ended September 30, 2022 2021 2020 Computed tax (21%) $ 188.0 $ 44.9 $ (9.6) Enacted tax law and changes in deferred tax rates 0.9 40.0 10.2 Gain on investment in BellRing (a) (91.8) — — Non-deductible compensation 5.9 5.4 4.5 State income tax, net of effect on federal tax 10.3 1.7 (7.8) Valuation allowances 1.4 2.9 6.1 Net losses and basis difference attributable to equity method investment (14.1) (9.2) (6.5) Income tax credits (1.9) (1.5) (2.6) Rate differential on foreign income (10.2) (11.0) (10.7) Excess tax benefits for share-based payments (3.6) (6.1) (1.3) Gain on bargain purchase — (2.4) (2.5) Enhanced deduction for food donations (1.0) (0.8) (1.3) Return-to-provision and changes in prior year accruals (0.5) (2.8) (1.4) Other, net (none in excess of 5% of statutory tax) 2.3 (2.9) 1.6 Income tax expense (benefit) $ 85.7 $ 58.2 $ (21.3) (a) No deferred income taxes have been recorded with respect to the non-cash mark-to-market adjustment on the Company’s Investment in BellRing during the year ended September 30, 2022, as the Company expects to fully divest, and has already partially divested through the Debt-for-Equity Exchange, its remaining Investment in BellRing within 12 months of the BellRing Spin-off in a manner intended to qualify as tax-free for U.S. federal income tax purposes. See Note 4 for additional information on the BellRing Spin-off. Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Non-current deferred tax assets (liabilities) were as follows: September 30, 2022 September 30, 2021 Assets Liabilities Net Assets Liabilities Net Derivatives and mark-to-market adjustments $ 34.9 $ — $ 34.9 $ 100.0 $ — $ 100.0 Disallowed interest carryforwards 55.4 — 55.4 34.2 — 34.2 Lease liabilities 35.8 — 35.8 31.9 — 31.9 Net operating loss and credit carryforwards 24.1 — 24.1 29.1 — 29.1 Stock-based and deferred compensation 19.9 — 19.9 17.5 — 17.5 Accrued liabilities 7.0 — 7.0 9.4 — 9.4 Accrued vacation, incentive and severance 6.2 — 6.2 8.2 — 8.2 Inventory 8.8 — 8.8 4.1 — 4.1 Intangible assets — (611.4) (611.4) — (643.5) (643.5) Property — (197.6) (197.6) — (218.7) (218.7) ROU assets — (32.9) (32.9) — (30.0) (30.0) Pension and other postretirement benefits (11.4) (11.4) — (21.7) (21.7) Basis difference attributable to equity method investment 4.6 — 4.6 — (11.8) (11.8) Other items 5.5 (1.8) 3.7 5.6 (1.8) 3.8 Total gross deferred income taxes 202.2 (855.1) (652.9) 240.0 (927.5) (687.5) Valuation allowance (35.5) — (35.5) (41.6) — (41.6) Total deferred taxes $ 166.7 $ (855.1) $ (688.4) $ 198.4 $ (927.5) $ (729.1) As of September 30, 2022, the Company’s $24.1 deferred tax asset for net operating loss (“NOL”) and credit carryforwards is comprised of U.S. federal NOL carryforwards of $1.9, state NOLs of $13.5, foreign tax loss carryforwards of $5.3 and state credit carryforwards of $3.4. The expiration for the majority of these carryforwards are either greater than 10 years or are able to be carried forward indefinitely. The Company has offset approximately $13.4 of the state NOLs and all of the $5.3 of foreign tax loss carryforwards by a valuation allowance based on management’s judgment that it is more likely than not that the benefits of those deferred tax assets will not be realized in the future. In addition, as of September 30, 2022, the Company had a deferred tax asset for disallowed U.S. interest expense of $55.4 subject to Internal Revenue Code Section 163(j) limitations, which may be carried forward indefinitely. Based on management’s judgement, with the exception of a $4.8 valuation allowance recorded for state-related disallowed interest carryforwards, it is more likely than not that the Company will recognize the benefit of this deferred tax asset in the future. As of September 30, 2022 and 2021, the Company had a recognized valuation allowance of $35.5 and $41.6, respectively, based on management’s judgment that it is more likely than not that the benefits of its deferred tax assets will not be realized in the future. The changes in the valuation allowance during the years ended September 30, 2022, 2021 and 2020 were $(6.1), $0.5 and $8.5, respectively. These changes primarily relate to valuation allowances on state carryforwards. The Company generally repatriates a portion of current year earnings from select non-U.S. subsidiaries only if the economic cost of the repatriation is not considered material. No provision has been made for income taxes on undistributed earnings of consolidated foreign subsidiaries of $90.0 as of September 30, 2022, as it is the Company’s intention to indefinitely reinvest undistributed earnings of its foreign subsidiaries to, amongst other things, fund local operations, fund debt service payments, fund pension and other post-retirement obligations, fund capital projects and support foreign growth initiatives, including potential acquisitions. If the Company repatriated any of the earnings, it could be subject to withholding tax and the impact of foreign currency movements. It is not practicable to estimate the additional income taxes and applicable foreign withholding taxes that would be payable on the remittance of such undistributed earnings. Applicable income and withholding taxes will be provided on these earnings in the periods in which they are no longer considered reinvested. U.K. Tax Law Changes In fiscal 2021, the effective income tax rate was impacted by enacted tax law changes in the U.K., which included a provision to increase the U.K.’s corporate income tax rate from 19% to 25%, effective April 1, 2023. During the years ended September 30, 2022 and 2021, the Company remeasured its existing deferred tax assets and liabilities considering the 25% U.K. corporate income tax rate for future periods and recorded tax expense of $0.9 and $40.0. Other changes made to the U.K.’s tax laws did not have a material impact on the Company’s financial statements during the years ended September 30, 2022 and 2021. Additionally, in fiscal 2020, the effective income tax rate was impacted by enacted tax law changes in the U.K., which included a provision to increase the U.K.’s corporate income tax rate from 17% to 19%. During the year ended September 30, 2020, the Company remeasured its existing deferred tax assets and liabilities considering the 19% U.K. corporate income tax rate for future periods and recorded tax expense of $13.0. Unrecognized Tax Benefits The Company recognizes the tax benefit from uncertain tax positions only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities. The tax benefits recognized from such positions are measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. To the extent the Company’s assessment of such tax positions changes, the change in estimate will be recorded in the period in which the determination is made. Unrecognized tax benefits activity for the years ended September 30, 2022, 2021 and 2020 is presented in the following table. September 30, 2022 2021 2020 Balance, beginning of year $ 12.5 $ 8.3 $ 8.6 Additions for tax positions taken in current year and acquisitions 0.1 0.3 0.2 Additions for tax positions taken in prior years — 5.2 — Settlements with tax authorities/statute expirations (0.9) (1.3) (0.5) Balance, end of year $ 11.7 $ 12.5 $ 8.3 The amount of the net unrecognized tax benefits that, if recognized, would directly affect the effective income tax rate was $6.5 at September 30, 2022. The Company believes that, due to expiring statutes of limitations and settlements with tax authorities, it is reasonably possible that the total unrecognized tax benefits may decrease up to approximately $0.2 within twelve months of the reporting date. The Company computes tax-related interest and penalties as the difference between the tax position recognized for financial reporting purposes and the amount previously taken on the Company’s tax returns and classifies these amounts as components of income tax expense (benefit). The Company recorded income tax expense (benefit) of $0.1, $(0.5) and zero related to interest and penalties in the years ended September 30, 2022, 2021 and 2020, respectively. The Company had accrued interest and penalties of $0.6 and $0.5 at September 30, 2022 and 2021, respectively. The accrued interest and penalties are not included in the table above.

Earnings per Share

Earnings per Share	12 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Earnings per Share	EARNINGS PER SHARE The following table sets forth the computation of basic and diluted earnings (loss) per share for both continuing and discontinued operations. Year ended September 30, 2022 2021 2020 Net Earnings (Loss) from Continuing Operations Net earnings (loss) from continuing operations $ 735.0 $ 104.9 $ (56.5) Impact of redeemable NCI — (11.0) — Net earnings (loss) from continuing operations for basic earnings (loss) per share $ 735.0 $ 93.9 $ (56.5) Impact of interest expense, net of tax, related to convertible senior notes 1.5 — — Net earnings (loss) from continuing operations for diluted earnings (loss) per share $ 736.5 $ 93.9 $ (56.5) Net Earnings from Discontinued Operations Net earnings from discontinued operations for basic earnings per share $ 21.6 $ 61.8 $ 57.3 Dilutive impact of Old BellRing net earnings from discontinued operations — (0.1) — Net earnings from discontinued operations for diluted earnings per share $ 21.6 $ 61.7 $ 57.3 Net Earnings Net earnings for basic earnings per share $ 756.6 $ 155.7 $ 0.8 Net earnings for diluted earnings per share $ 758.1 $ 155.6 $ 0.8 shares in millions Weighted-average shares for basic earnings per share 60.9 64.2 68.9 Effect of dilutive securities: Stock options 0.3 0.6 — Stock appreciation rights 0.1 0.1 — Restricted stock units 0.5 0.3 — Market-based performance restricted stock units 0.1 0.1 — Earnings-based performance restricted stock units 0.1 — — Shares issuable upon conversion of convertible senior notes 0.7 — — Total dilutive securities 1.8 1.1 — Weighted-average shares for diluted earnings per share 62.7 65.3 68.9 Earnings (Loss) from Continuing Operations per Common Share: Basic $ 12.07 $ 1.46 $ (0.82) Diluted $ 11.75 $ 1.44 $ (0.82) Earnings from Discontinued Operations per Common Share: Basic $ 0.35 $ 0.96 $ 0.83 Diluted $ 0.34 $ 0.94 $ 0.83 Earnings per Common Share: Basic $ 12.42 $ 2.42 $ 0.01 Diluted $ 12.09 $ 2.38 $ 0.01 The following table details the securities that have been excluded from the calculation of weighted-average shares for diluted earnings (loss) per share for both continuing and discontinued operations as they were anti-dilutive. Year ended September 30, 2022 2021 2020 Stock options — — 1.6 Stock appreciation rights — — 0.1 Restricted stock units 0.3 — 0.5 Market-based performance restricted stock units 0.1 — 0.2

Supplemental Operations Stateme

Supplemental Operations Statement and Cash Flow Information	12 Months Ended
	Sep. 30, 2022
Supplemental Operations Statement and Cash Flow Information [Abstract]
Supplemental Operations Statement and Cash Flow Information	SUPPLEMENTAL OPERATIONS STATEMENT AND CASH FLOW INFORMATION Year Ended September 30, 2022 2021 2020 Advertising expenses $ 93.2 $ 112.3 $ 113.1 Research and development expenses 18.9 21.9 19.1 Interest income (4.4) (0.6) (6.2) Interest paid 320.0 348.2 300.0 Income taxes paid 45.8 45.6 44.4 Accrued additions to property 36.4 38.3 29.8

Supplemental Balance Sheet Info

Supplemental Balance Sheet Information	12 Months Ended
	Sep. 30, 2022
Supplemental Balance Sheet Information [Abstract]
Supplemental Balance Sheet Information	SUPPLEMENTAL BALANCE SHEET INFORMATION September 30, 2022 2021 Receivables, net Trade $ 499.4 $ 374.8 Income tax receivable 17.4 57.2 Related party 4.4 4.6 Other 25.3 18.0 546.5 454.6 Allowance for credit losses (2.3) (2.2) $ 544.2 $ 452.4 Inventories Raw materials and supplies $ 130.9 $ 99.6 Work in process 21.1 19.2 Finished products 361.9 318.7 Flocks 35.2 39.1 $ 549.1 $ 476.6 Other Assets Pension asset $ 93.9 $ 153.4 Operating ROU assets 122.9 115.5 Other investments 26.9 22.9 Derivative assets 3.0 29.1 Other 20.1 27.1 $ 266.8 $ 348.0 Accounts Payable Trade $ 362.1 $ 369.1 Book cash overdrafts 53.3 1.5 Related party 26.1 1.2 Other 11.2 12.4 $ 452.7 $ 384.2 Other Current Liabilities Advertising and promotion $ 47.2 $ 40.2 Accrued interest 69.5 68.1 Accrued compensation 63.4 41.7 Hedging liabilities 25.9 127.7 Operating lease liabilities 25.5 23.5 Accrued freight 25.1 24.0 Other accrued taxes 19.1 21.6 Other 94.3 68.2 $ 370.0 $ 415.0 Other Liabilities Pension and other postretirement benefit obligations $ 45.6 $ 64.2 Derivative liabilities 49.1 256.0 Accrued compensation 33.1 36.1 Operating lease liabilities 113.7 105.2 Other 25.4 46.4 $ 266.9 $ 507.9

Derivative Financial Instrument

Derivative Financial Instruments and Hedging	12 Months Ended
	Sep. 30, 2022
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments and Hedging	DERIVATIVE FINANCIAL INSTRUMENTS AND HEDGINGIn the ordinary course of business, the Company is exposed to commodity price risks relating to the purchases of raw materials and supplies, interest rate risks relating to floating rate debt and foreign currency exchange rate risks. The Company utilizes derivative financial instruments, including (but not limited to) futures contracts, option contracts, forward contracts and swaps, to manage certain of these exposures by hedging when it is practical to do so. The Company does not hold or issue financial instruments for speculative or trading purposes. At September 30, 2022, the Company’s derivative instruments, none of which were designated as hedging instruments under ASC Topic 815, “Derivatives and Hedging,” consisted of: • commodity and energy futures, swaps and option contracts which relate to inputs that generally will be utilized within the next two years; • foreign currency forward contracts maturing in the next year that have the effect of hedging currency fluctuations between the Euro and the Pound Sterling; • interest rate swaps that have the effect of hedging interest payments on debt expected to be issued but not yet priced, including: • a pay-fixed, receive-variable interest rate swap maturing in May 2024 that requires monthly settlements; • rate-lock interest rate swaps that require lump sum settlements with the first settlement occurring in July 2023 and the last in July 2026; and • interest rate swaps that mature in June 2023 and give the Company the option of pay-variable, receive-fixed lump sum settlements; and • the PHPC Warrants (see Note 5). Interest rate swaps In fiscal 2022, the Company terminated $700.0 notional value of its rate-lock interest rate swap contracts. In connection with this termination, the Company paid $17.0, which was recorded in “(Income) expense on swaps, net” in the Consolidated Statement of Operations for the year ended September 30, 2022. The Company also restructured two of its rate-lock interest rate swap contracts, which contain non-cash, off-market financing elements. There were no cash settlements paid or received in connection with these restructurings. In fiscal 2021, the Company restructured four of its rate-lock interest rate swap contracts, which contain non-cash, off-market financing elements. There were no cash settlements paid or received in connection with these restructurings. In fiscal 2020, contemporaneously with the repayment of its term loan, the Company changed the designation of one of its interest rate swap contracts from a cash flow hedge to a non-designated hedging instrument. In connection with the de-designation, the Company reclassified losses previously recorded in accumulated OCI of $7.2 to “Interest expense, net” in the Consolidated Statement of Operations for the year ended September 30, 2020. Cross-currency swaps The Company terminated $448.7 notional value of its cross-currency swap contracts that were designated as hedging instruments during fiscal 2020. In connection with this termination, the Company received cash proceeds of $50.3 during the year ended September 30, 2020, which was recorded to accumulated OCI. Reclassification of amounts recorded in accumulated OCI into earnings will only occur in the event U.K.-based operations are substantially liquidated. The following table shows the notional amounts of derivative instruments held. September 30, September 30, Commodity contracts $ 145.0 $ 56.4 Energy contracts 23.7 45.9 Foreign exchange contracts - Forward contracts 3.2 — Interest rate swap 200.0 200.0 Interest rate swaps - Rate-lock swaps 849.3 1,549.3 Interest rate swaps - Options 332.6 — PHPC Warrants 16.9 16.9 The following table presents the balance sheet location and fair value of the Company’s derivative instruments. The Company does not offset derivative assets and liabilities within the Consolidated Balance Sheets. Balance Sheet Location September 30, September 30, Asset Derivatives: Commodity contracts Prepaid expenses and other current assets $ 12.9 $ 16.3 Energy contracts Prepaid expenses and other current assets 13.6 20.1 Interest rate swaps Prepaid expenses and other current assets 3.4 — Commodity contracts Other assets 0.5 2.9 Energy contracts Other assets — 2.0 Interest rate swaps Other assets 2.5 24.2 $ 32.9 $ 65.5 Liability Derivatives: Commodity contracts Other current liabilities $ 1.5 $ 2.8 Energy contracts Other current liabilities 1.8 — Interest rate swaps Other current liabilities 22.5 124.9 Foreign exchange contracts Other current liabilities 0.1 — Interest rate swaps Other liabilities 48.1 246.8 PHPC Warrants Other liabilities 1.0 9.2 $ 75.0 $ 383.7 The following table presents the effects of the Company’s derivative instruments on the Company’s Consolidated Statements of Operations. Derivatives Not Designated as Hedging Instruments Statement of Operations Location (Gain) Loss Recognized in Statement of Operations 2022 2021 2020 Commodity contracts Cost of goods sold $ (32.2) $ (11.3) $ 3.8 Energy contracts Cost of goods sold (28.5) (43.1) 21.6 Foreign exchange contracts Selling, general and administrative expenses 0.1 0.1 (0.1) Interest rate swaps (Income) expense on swaps, net (268.0) (122.8) 187.1 PHPC Warrants Other income, net (8.2) (7.7) — The following table presents the effects of the Company’s derivative instruments on the Company’s Consolidated Statement of Comprehensive Income for the year ended September 30, 2020. The effects of the Company’s derivative instruments for the years ended September 30, 2022 and 2021 included in the Company’s Consolidated Statements of Comprehensive Income related to the Company’s discontinued operations and therefore were not included in the table below. Derivatives Designated as Hedging Instruments Gain Recognized in OCI Loss Reclassified from Accumulated OCI into Earnings (a) Statement of Operations Location Interest rate swaps $ (0.6) $ 7.2 Interest expense, net Cross-currency swaps (32.2) — (Income) expense on swaps, net (a) This amount includes the amortization of previously unrealized losses on interest rate swaps that were de-designated as hedging instruments in the first quarter of fiscal 2020. Accumulated OCI included a $99.5 net gain on hedging instruments before taxes ($74.9 after taxes) at both September 30, 2022 and September 30, 2021 related to settlements of and previously unrealized gains on cross-currency swaps. Reclassification of these amounts recorded in accumulated OCI into earnings will only occur in the event all U.K.-based operations are substantially liquidated. At September 30, 2022 and 2021, the Company had pledged collateral of $2.8 and $6.4, respectively, related to its commodity and energy contracts. These amounts were classified as “Restricted cash” on the Consolidated Balance Sheets.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The following table presents the assets and liabilities measured at fair value on a recurring basis and the basis for that measurement according to the levels in the fair value hierarchy in ASC Topic 820, “Fair Value Measurement.” September 30, 2022 September 30, 2021 Total Level 1 Level 2 Total Level 1 Level 2 Assets: Deferred compensation investment $ 12.0 $ 12.0 $ — $ 15.5 $ 15.5 $ — Derivative assets 32.9 — 32.9 65.5 — 65.5 Equity securities 32.1 32.1 — 28.9 28.9 — Investment in BellRing 94.8 94.8 — — — — $ 171.8 $ 138.9 $ 32.9 $ 109.9 $ 44.4 $ 65.5 Liabilities: Deferred compensation liabilities $ 33.7 $ — $ 33.7 $ 36.0 $ — $ 36.0 Derivative liabilities 75.0 1.0 74.0 383.7 9.2 374.5 $ 108.7 $ 1.0 $ 107.7 $ 419.7 $ 9.2 $ 410.5 Deferred Compensation The deferred compensation investments are primarily invested in mutual funds, and their fair value is measured using the market approach. These investments are in the same funds, or funds that employ a similar investment strategy, and are purchased in substantially the same amounts, as the participants’ selected investment options (excluding Post common stock equivalents), which represent the underlying liabilities to participants in the Company’s deferred compensation plans. Deferred compensation liabilities are recorded at amounts due to participants in cash, based on the fair value of participants’ selected investment options (excluding certain Post common stock equivalents to be distributed in shares) using the market approach. Derivatives The Company utilizes the income approach to measure fair value for its commodity and energy derivatives. The income approach uses pricing models that rely on market observable inputs such as yield curves and forward prices. Foreign exchange contracts are valued using the spot rate less the forward rate multiplied by the notional amount. The Company’s calculation of the fair value of interest rate swaps is derived from a discounted cash flow analysis based on the terms of the contract and the interest rate curve. Refer to Note 13 for the classification of changes in fair value of derivative assets and liabilities measured at fair value on a recurring basis within the Consolidated Statements of Operations. The PHPC Warrants were initially valued using the Monte Carlo Option Pricing Method. The initial fair value measurement was categorized as Level 3, as the fair values utilized significant unobservable inputs. However, as of September 30, 2022 an d 2021 , the PHPC Warrants were valued using the market approach based on quoted prices as the PHPC Warrants became actively traded on the NYSE during the fourth quarter of fiscal 2021 and are now categorized as Level 1. For additional information on the PHPC Warrants, see Notes 5 and 13. Equity Securities and Investment in BellRing The Company uses the market approach to measure the fair value of its equity securities. The Company’s Investment in BellRing represented its 3.4% equity interest in BellRing as of September 30, 2022, which was measured at its fair value of $94.8 based on the trading value of the BellRing Common Stock on September 30, 2022. For additional information on the Company’s Investment in BellRing, see Notes 4 and 5. Other Fair Value Measurements Investments held in trust are invested in a fund consisting entirely of U.S. treasury securities. The fund is valued at net asset (“NAV”) per share, and as such, in accordance with ASC Topic 820, the investments have not been classified in the fair value hierarchy. Investments held in trust are reported at fair value on the Consolidated Balance Sheets (see Note 5). The Company’s financial assets and liabilities also include cash and cash equivalents, receivables and accounts payable for which the carrying value approximates fair value due to their short maturities (less than 12 months). The Company does not record its current portion of long-term debt and long-term debt at fair value on the Consolidated Balance Sheets. The fair value of any outstanding borrowings under the municipal bond as of September 30, 2022 and 2021 approximated their carrying values. Based on current market rates, the fair value (Level 2) of the Company’s debt, excluding outstanding borrowings under the municipal bond (which are also categorized as Level 2), was $5,171.0 and $6,596.7 as of September 30, 2022 and 2021, respectively, which included $566.1 and zero related to the Company’s convertible senior notes, respectively. Certain assets and liabilities, including property, goodwill, other intangible assets and assets held for sale, are measured at fair value on a non-recurring basis. No impairment charges were recorded for property, goodwill, definite-lived or indefinite-lived intangibles or assets held for sale during the years ended September 30, 2022, 2021 or 2020. At September 30, 2020, the Company had land and buildings classified as assets held for sale related to the closures of the Clinton Plant, the Asheboro Facility and the Corby Facility. The Company sold the Asheboro Facility, the Corby Facility and the Clinton Plant in fiscal 2021. The Clinton Plant and the Asheboro Facility were both reported in the Post Consumer Brands segment, and the Corby Facility was reported in the Weetabix segment. The Company sold the Klingerstown Equipment and entered into an agreement to sell the Jefferson City Equipment in fiscal 2022. The Klingerstown Equipment and the Jefferson City Equipment were reported in the Foodservice segment. For additional information on assets held for sale, see Note 7. The fair value of assets held for sale was measured on a non-recurring basis based on the lower of the carrying amount or fair value less cost to sell. When applicable, the fair value is adjusted to reflect an offer to purchase the assets. The fair value measurement was categorized as Level 3, as the fair values utilize significant unobservable inputs. The following table summarizes the Level 3 activity. Balance, September 30, 2020 $ 7.3 Proceeds from the sale of assets held for sale (7.9) Currency translation adjustment 0.1 Net gain related to assets held for sale 0.5 Balance, September 30, 2021 $ — Transfers of assets into held for sale 1.0 Net gain related to assets held for sale 9.4 Proceeds from the sale of assets held for sale (10.3) Balance, September 30, 2022 $ 0.1

Leases

Leases	12 Months Ended
	Sep. 30, 2022
Leases [Abstract]
Lessee, Operating Leases	LEASES The Company leases office space, certain warehouses, manufacturing facilities and equipment primarily through operating lease agreements. The Company has no material finance lease agreements. Leases have remaining terms which range from 1 to 54 years and most leases provide the Company with the option to exercise one or more renewal terms. ROU assets are recorded as “Other assets” and lease liabilities are recorded as “Other current liabilities” and “Other liabilities” on the Consolidated Balance Sheets. Operating lease expense is recognized on a straight-line basis over the lease term and is included in either “Cost of goods sold” or “Selling, general and administrative expenses” in the Consolidated Statements of Operations. Costs associated with finance leases and lease income do not have a material impact on the Company’s financial statements. The following table presents the balance sheet location of the Company’s operating leases. September 30, 2022 September 30, 2021 ROU assets: Other assets $ 122.9 $ 115.5 Lease liabilities: Other current liabilities $ 25.5 $ 23.5 Other liabilities 113.7 105.2 Total lease liabilities $ 139.2 $ 128.7 The following table presents maturities of the Company’s operating lease liabilities. September 30, 2022 Fiscal 2023 $ 32.1 Fiscal 2024 26.3 Fiscal 2025 20.4 Fiscal 2026 18.9 Fiscal 2027 14.5 Thereafter 64.3 Total future minimum payments $ 176.5 Less: Implied interest 37.3 Total lease liabilities $ 139.2 The following table presents supplemental information related to the Company’s operating leases. Year Ended September 30, 2022 2021 2020 Operating lease expense $45.5 $40.1 $38.0 Variable lease expense 5.2 4.8 4.5 Short-term lease expense 9.4 7.5 7.4 Weighted-average remaining lease term 9 years 9 years 7 years Weighted-average IBR 5.26% 4.70% 4.46% Operating cash flows for amounts included in the measurement of the Company’s operating lease liabilities for the years ended September 30, 2022, 2021 and 2020 were $29.6, $28.4 and $26.0, respectively. ROU assets obtained in exchange for operating lease liabilities during the years ended September 30, 2022, 2021 and 2020 were $20.7, $33.8 and $5.3, respectively. Of the $33.8 ROU assets obtained in exchange for operating lease liabilities during the year ended September 30, 2021, $27.7 related to the acquisition of Almark (see Note 5).

Long Term Debt

Long Term Debt	12 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Long-term Debt	LONG-TERM DEBT Long-term debt as of the dates indicated consists of the following: September 30, 2022 2021 2.50% convertible senior notes maturing August 2027 $ 575.0 $ — 4.50% senior notes maturing September 2031 1,270.5 1,800.0 4.625% senior notes maturing April 2030 1,482.2 1,650.0 5.50% senior notes maturing December 2029 1,235.0 750.0 5.625% senior notes maturing January 2028 940.9 940.9 5.75% senior notes maturing March 2027 459.3 1,299.3 Municipal bond 6.4 7.5 $ 5,969.3 $ 6,447.7 Less: Current portion of long-term debt 1.1 1.1 Debt issuance costs, net 50.1 47.2 Plus: Unamortized premium, net 38.5 42.2 Total long-term debt $ 5,956.6 $ 6,441.6 Debt Transactions in Connection with BellRing On March 8, 2022, the Company entered into a Joinder Agreement No. 1 (the “First Joinder Agreement”) by and among the Company, as borrower, certain of the Company’s subsidiaries, as guarantors, the institutions constituting the Funding Incremental Term Loan Lenders (as defined in the First Joinder Agreement, referred to herein as the “First Funding Incremental Term Loan Lenders”), Barclays Bank PLC, as administrative agent, and JPMorgan Chase Bank, N.A., as sub-agent to the administrative agent. The First Joinder Agreement provided for an incremental term loan (the “First Incremental Term Loan”) of $840.0 under the Company’s Credit Agreement (as defined below), which the Company borrowed in full on March 8, 2022. Interest on the First Incremental Term Loan accrued at the adjusted term secured overnight financing rate (“SOFR”) rate (as defined in the Credit Agreement) plus a margin of 1.50% per annum, and the maturity date for the First Incremental Term Loan was May 6, 2022. The First Joinder Agreement permitted the Company to repay the First Incremental Term Loan, in whole or in part, in cash or, with prior written consent of the First Funding Incremental Term Loan Lenders, in lieu of cash, to exchange its obligations under the First Incremental Term Loan with the First Funding Incremental Term Loan Lenders for the BellRing Notes. On March 10, 2022, the Company and the First Funding Incremental Term Loan Lenders entered into an exchange agreement (the “First Exchange Agreement”) pursuant to which the Company repaid the First Incremental Term Loan and all accrued and unpaid interest and expenses owed thereunder through a combination of (i) with respect to the principal amount owed under the First Incremental Term Loan, the assignment and transfer by the Company of all $840.0 of the BellRing Notes to the First Funding Incremental Term Loan Lenders and (ii) with respect to accrued and unpaid interest and fees and expenses owed under the First Incremental Term Loan, cash on hand (collectively, the “Debt-for-Debt Exchange”). As provided in the First Exchange Agreement, upon completion of the transfer of the BellRing Notes to the First Funding Incremental Term Loan Lenders and payment of interest, fees and expenses, the First Incremental Term Loan was deemed satisfied and paid in full. For additional information, see “Repayments of Debt” below. On March 17, 2022, the Company redeemed $840.0 in aggregate principal amount, or approximately 65%, of the outstanding 5.75% senior notes maturing in March 2027 using the proceeds from the First Incremental Term Loan. The 5.75% senior notes were redeemed at a redemption price of 102.875% of the aggregate principal amount of the 5.75% senior notes being redeemed, plus accrued and unpaid interest for each day from March 1, 2022 to, but excluding, March 17, 2022. For additional information, see “Repayments of Debt” below. On July 25, 2022, the Company entered into a Joinder Agreement No. 2 (the “Second Joinder Agreement”) by and among the Company, as borrower, certain of the Company’s subsidiaries, as guarantors, the institutions constituting the Funding Incremental Term Loan Lenders (as defined in the Second Joinder Agreement, referred to herein as the “Second Funding Incremental Term Loan Lenders”), Barclays Bank PLC, as administrative agent, and JPMorgan Chase Bank, N.A., as sub-agent to the administrative agent. The Second Joinder Agreement provided for an incremental term loan (the “Second Incremental Term Loan”) of $450.0 under the Company’s Credit Agreement, which the Company borrowed in full on July 25, 2022. Interest on the Second Incremental Term Loan accrued at the adjusted term SOFR rate plus a margin of 1.50% per annum, and the maturity date for the Second Incremental Term Loan was September 23, 2022. The Second Joinder Agreement permitted the Company to repay the Second Incremental Term Loan, in whole or in part, in cash or, with the prior written consent of the Second Funding Incremental Term Loan Lenders, with an alternative form of consideration in lieu of cash. On August 8, 2022, the Company and the Second Funding Incremental Term Loan Lenders entered into an exchange agreement (the “Second Exchange Agreement”) pursuant to which the Company transferred on August 11, 2022 14.8 million shares of its Investment in BellRing to the Second Funding Incremental Term Loan Lenders to repay $342.3 in aggregate principal amount of the Second Incremental Term Loan, excluding accrued interest, which was paid with cash (such exchange, the “Debt-for-Equity Exchange”). On September 14, 2022, the Company repaid the remaining principal balance of $107.7 of the Second Incremental Term Loan using cash on hand. For additional information, see “Repayments of Debt” below. Convertible Senior Notes On August 12, 2022, the Company issued $575.0 principal value of 2.50% convertible senior notes maturing in August 2027. The 2.50% convertible senior notes were issued at par, and the Company received $559.1 after incurring investment banking and other fees and expenses of $15.9, which were deferred and are being amortized to interest expense over the term of the 2.50% convertible senior notes. Interest payments on the 2.50% convertible senior notes are due semi-annually each February 15 and August 15, beginning on February 15, 2023. With a portion of the net proceeds received from the issuance, the Company repurchased 1.1 million shares of its common stock in privately negotiated transactions effected through one of the initial purchasers of the 2.50% convertible senior notes (or an affiliate thereof), as the Company’s agent, and paid the fees and expenses associated with the repurchase (see Note 20 ) . The Company intends to use the remainder of the net proceeds for general corporate purposes. The initial conversion rate of the 2.50% convertible senior notes is 9.4248 shares of the Company’s common stock per one thousand principal amount of notes, which represents an initial conversion price of approximately $106.10 per share of common stock. The conversion rate, and thus the conversion price, may be adjusted under certain circumstances as described in the indenture governing the 2.50% convertible senior notes (the “Indenture”). The Company may settle conversions by paying or delivering, as applicable, cash, shares of its common stock or a combination of cash and shares of its common stock, at the Company’s election. If a “make-whole fundamental change” (as defined in the Indenture) occurs, then the Company will in certain circumstances increase the conversion rate for a specified period of time. The 2.50% convertible senior notes may be converted at the holder’s option up to the second scheduled trading day immediately before the maturity date of August 15, 2027 under the following circumstances: • during any calendar quarter (and only during such calendar quarter) commencing after the calendar quarter ended September 30, 2022, if the last reported sale price per share of the Company’s common stock exceeds 130% of the conversion price for each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter; • during the five consecutive business days immediately after any 10 consecutive trading day period (such 10 consecutive trading day period, the “Measurement Period”) in which the trading price per one thousand principal amount of notes for each trading day of the Measurement Period was less than 98% of the product of the last reported sale price per share of the Company’s common stock on such trading day and the conversion rate on such trading day; • upon the occurrence of certain corporate events or distributions on the Company’s common stock described in the Indenture; • if the Company calls the notes for redemption; and • at any time from, and including, May 15, 2027 until the close of business on the second scheduled trading day immediately before the August 15, 2027 maturity date. If a “fundamental change” (as defined in the Indenture) occurs, then, except as described in the Indenture, holders of the 2.50% convertible senior notes may require the Company to repurchase their notes at a cash repurchase price equal to the principal amount of the 2.50% convertible senior notes to be repurchased, plus accrued and unpaid interest, if any, to, but excluding, the “fundamental change repurchase date” (as defined in the Indenture). The 2.50% convertible senior notes may be redeemed, in whole or in part (subject to the partial redemption limitation described in the Indenture), at the Company’s option at any time, and from time to time, on or after August 20, 2025 and on or before the 35th scheduled trading day immediately before August 15, 2027, at a cash redemption price equal to the principal amount of the notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date, only if the last reported sale price per share of the Company’s common stock exceeds 130% of the conversion price on (i) each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date the Company sends the related redemption notice, and (ii) the trading day immediately before the date the Company sends such notice. As of September 30, 2022 , none of the conditions permitting holders to convert their 2.50% convertible senior notes had been satisfied, and no shares of the Company’s common stock had been issued in connection with any conversions of the 2.50% convertible senior notes. The Company evaluated the terms of the 2.50% convertible senior notes and concluded there were no embedded features that required separate bifurcation under ASC Topic 815. As such, the 2.50% convertible senior notes were recorded at the principal amount, net of issuance costs, on the Company’s Consolidated Balance Sheet at the time of issuance. As of September 30, 2022, the net carrying value of the 2.50% convertible senior notes was $559.5, which included $15.5 of unamortized debt issuance costs. The Company’s 2.50% convertible senior notes are fully and unconditionally guaranteed, jointly and severally, on a senior, unsecured basis, by each of the Company’s existing domestic subsidiaries that have guaranteed its other senior notes, which excludes certain immaterial subsidiaries, certain excluded subsidiaries and subsidiaries the Company designated as unrestricted subsidiaries, which include 8th Avenue and its subsidiaries, PHPC and PHPC Sponsor. If, after the date the 2.50% convertible senior notes were issued, any domestic wholly-owned subsidiary of the Company guarantees any of the Company’s existing 2.50% convertible senior notes or any other debt securities the Company may issue in the form of senior unsecured notes or convertible or exchangeable notes, then the Company will cause such subsidiary to become a guarantor under the 2.50% convertible senior notes as well. Other Senior Notes On February 14, 2017, the Company issued $750.0 principal value of 5.75% senior notes maturing in March 2027. The 5.75% senior notes were issued at par, and the Company received $739.5 after incurring investment banking and other fees and expenses of $10.5, which were deferred and are being amortized to interest expense over the term of the 5.75% senior notes. On August 10, 2017, the Company issued an additional $750.0 principal value of 5.75% senior notes. The additional 5.75% senior notes were issued at a price of 105.5% of par value, and the Company received $784.0 after incurring investment banking and other fees and expenses of $7.2, which were deferred and are being amortized to interest expense over the term of the 5.75% senior notes. The premium related to the additional 5.75% senior notes was recorded as an unamortized premium and is being amortized as a reduction to interest expense over the term of the 5.75% senior notes. Interest payments on the 5.75% senior notes are due semi-annually each March 1 and September 1. On December 1, 2017, the Company issued $1,000.0 principal value of 5.625% senior notes maturing in January 2028. The 5.625% senior notes were issued at par, and the Company received $990.6 after incurring investment banking and other fees and expenses of $9.4, which were deferred and are being amortized to interest expense over the term of the 5.625% senior notes. Interest payments on the 5.625% senior notes are due semi-annually each January 15 and July 15. On July 3, 2019, the Company issued $750.0 principal value of 5.50% senior notes maturing in December 2029. The 5.50% senior notes were issued at par, and the Company received $743.0 after incurring investment banking and other fees and expenses of $7.0, which were deferred and are being amortized to interest expense over the term of the 5.50% senior notes. On December 22, 2021, the Company issued an additional $500.0 principal value of 5.50% senior notes. The additional 5.50% senior notes were issued at a price of 103.5% of the par value, and the Company received $514.0 after incurring investment banking and other fees and expenses of $3.5, which were deferred and are being amortized to interest expense over the term of the 5.50% senior notes. The premium related to the additional 5.50% senior notes was recorded as an unamortized premium and is being amortized as a reduction to interest expense over the term of the 5.50% senior notes. Interest payments on the 5.50% senior notes are due semi-annually each June 15 and December 15. On February 26, 2020, the Company issued $1,250.0 principal value of 4.625% senior notes maturing in April 2030. The 4.625% senior notes were issued at par, and the Company received $1,241.0 after incurring investment banking and other fees and expenses of $9.0, which were deferred and are being amortized to interest expense over the term of the 4.625% senior notes. On August 14, 2020, the Company issued an additional $400.0 principal value of 4.625% senior notes. The additional 4.625% senior notes were issued at a price of 105.5% of the par value, and the Company received $417.5 after incurring investment banking and other fees and expenses of $4.5 which were deferred and are being amortized to interest expense over the term of the 4.625% senior notes. The premium related to the additional 4.625% senior notes was recorded as an unamortized premium and is being amortized as a reduction of interest expense over the term of the 4.625% senior notes. Interest payments on the 4.625% senior notes are due semi-annually each April 15 and October 15. On March 10, 2021, th e Company issued $1,800.0 principal value of 4.50% senior notes maturing i n September 2 031. The 4.50% senior n otes were issued at par, and the Company receive d $1,783.2 after incurring investment banking and other fees and expenses of $16.8, which were d eferred and are being amortized to interest expense over the term of the 4.50% senior notes. Interest payments are du e semi-annually each March 15 and September 15. With the net proceeds received from the issuance, the Company redeemed the outstanding principal balance of the Company’s previously held 5.00% senior notes maturing in August 2026. For additional information, see “Repayments of Debt” below. All of the Company’s senior notes are fully and unconditionally guaranteed, jointly and severally, on a senior unsecured basis by each of the Company’s existing and future domestic subsidiaries, other than immaterial subsidiaries, receivables finance subsidiaries and subsidiaries the Company designated as unrestricted subsidiaries, which such unrestricted subsidiaries includes 8th Avenue and its subsidiaries, PHPC and PHPC Sponsor. These guarantees are subject to release in certain circumstances. Credit Agreement On March 18, 2020, the Company entered into a second amended and restated credit agreement (a s amended, including by the First Joinder Agreement and the Second Joinder Agreement, restated or amended and restated, the “Credit Agreement”). The Credit Agreement provides for a revolving credit facility in an aggregate principal amount of $750.0 (the “Revolving Credit Facility”), with the commitments thereunder to be made available to the Company in U.S. Dollars, Canadian Dollars, Euros and Pounds Sterling. Letters of credit are available under the Credit Agreement in an aggregate amount of up to $75.0 . The Company incurred $3.6 of issuance costs during the year ended September 30, 2020 in connection with entering into the Credit Agreement, which were deferred and are being amortized to interest expense over the term of the Credit Agreement. As of September 30, 2022 and 2021 , t he Revolving Credit Facility had outstanding letters of credit of $19.7 and $19.2 , respectively, which reduced the available borrowing capacity under the Revolving Credit Facility to $730.3 and $730.8, respectively . Any outstanding amounts under the Revolving Credit Facility must be repaid on or before March 18, 2025. The Credit Agreement provides for potential incremental revolving and term facilities at the request of the Company and at the discretion of the lenders or other persons providing such incremental facilities, in each case on terms to be determined, and also permits the Company to incur other secured or unsecured debt, in all cases subject to conditions and limitations on the amount as specified in the Credit Agreement. The Credit Agreement permits the Company to designate certain of its subsidiaries as unrestricted subsidiaries and once so designated, permits the disposition of (and authorizes the release of liens on) the assets of, and the equity interests in, such unrestricted subsidiaries and permits the release of such unrestricted subsidiaries as guarantors under the Credit Agreement. The Company’s obligations under the Credit Agreement are unconditionally guaranteed by its existing and subsequently acquired or organized domestic subsidiaries (other than immaterial subsidiaries, certain excluded subsidiaries and subsidiaries the Company designates as unrestricted subsidiaries, which include 8th Avenue and its subsidiaries, PHPC and PHPC Sponsor) and are secured by security interests in substantially all of the Company’s assets and the assets of its subsidiary guarantors, but excluding, in each case, real property. On September 3, 2021, the Company entered into an amendment to the Credit Agreement to change the reference interest rate applicable to revolving loan borrowings in Pounds Sterling from a Eurodollar rate-based rate to a rate based on the Sterling Overnight Index Average. On December 17, 2021, the Company entered into a second amendment to the Credit Agreement to, among other provisions, facilitate the BellRing Spin-off. For additional information regarding the BellRing Spin-off, see Note 4. The amendment also amended the Credit Agreement to change the reference interest rate applicable to revolving loan borrowings in U.S. Dollars from LIBOR to a rate based on the adjusted term SOFR rate. During the y ear ended September 30, 2022 , the Company paid $0.4 of deferred financing fees in connection with the amendment. Borrowings in U.S. Dollars under the Revolving Credit Facility bear interest, at the option of the Company, at an annual rate equal to either (a) the term SOFR rate or (b) the base rate determined by reference to the highest of (i) the prime rate, (ii) the federal funds rate plus 0.50% per annum and (iii) the one-month adjusted term SOFR rate plus 1.00% per annum, in each case plus an applicable margin, which is determined by reference to the secured net leverage ratio (as defined in the Credit Agreement), with the applicable margin for adjusted term SOFR rate loans and base rate loans being (i) 2.00% and 1.00%, respectively, if the secured net leverage ratio is greater than or equal to 3.00:1.00, (ii) 1.75% and 0.75%, respectively, if the secured net leverage ratio is less than 3.00:1.00 and greater than or equal to 1.50:1.00 or (iii) 1.50% and 0.50%, respectively, if the secured net leverage ratio is less than 1.50:1.00. Commitment fees on the daily unused amount of commitments under the Revolving Credit Facility accrue at a rate of 0.375% if the Company’s secured net leverage ratio is greater than 3.00:1.00, and accrue at a rate of 0.25% if the Company’s secured net leverage ratio is less than or equal to 3.00:1.00. The Credit Agreement provides for customary events of default, including material breach of representations and warranties, failure to make required payments, failure to comply with certain agreements or covenants, failure to pay or default under certain other indebtedness in excess of $100.0, certain events of bankruptcy and insolvency, inability to pay debts, the occurrence of one or more unstayed or undischarged judgments in excess of $100.0, attachments issued against all or any material part of the Company’s property, certain events under the Employee Retirement Income Security Act of 1974 (“ERISA”), a change of control (as defined in the Credit Agreement), the invalidity of any loan document and the failure of the collateral documents to create a valid and perfected first priority lien (subject to certain permitted liens). Upon the occurrence and during the continuance of an event of default, the maturity of the loans under the Credit Agreement may accelerate and the agent and lenders under the Credit Agreement may exercise other rights and remedies available at law or under the loan documents, including with respect to the collateral and guarantees of the Company’s obligations under the Credit Agreement. 2020 Bridge Loan On October 11, 2019, in connection with the initial public offering and formation of Old BellRing, the Company entered into a $1,225.0 bridge facility agreement (the “2020 Bridge Loan Facility”) and borrowed $1,225.0 under the 2020 Bridge Loan Facility (the “2020 Bridge Loan”). On October 21, 2019, BellRing LLC entered into a borrower assignment and assumption agreement with the Company and the administrative agent under the 2020 Bridge Loan Facility, under which BellRing LLC became the borrower under the 2020 Bridge Loan and assumed all interest of $2.2 thereunder, and the Company and its subsidiary guarantors (other than BellRing LLC and its domestic subsidiaries, who were subsidiaries of the Company at the time) were released from all material obligations thereunder. The Company retained the net cash proceeds of the 2020 Bridge Loan, and following the assumption by BellRing LLC of the 2020 Bridge Loan Facility, used the cash proceeds of the 2020 Bridge Loan to repay a portion of the $1,309.5 principal balance of its previously outstanding term loan. For additional information, see “Repayments of Debt” below. Municipal Bond In connection with the construction of a filtration system at the Company’s potato plant in Chaska, Minnesota, the Company incurred debt that guarantees the repayment of certain industrial revenue bonds used to finance the construction of the project. Principal payments are due annually on March 1, and interest payments are due semi-annually each March 1 and September 1. The debt matures on March 1, 2028. Repayments of Debt On June 27, 2022, the Company commenced a modified “Dutch Auction” tender offer to purchase up to $450.0 in aggregate cash consideration (excluding accrued interest) of its (i) 4.625% senior notes at a bid range of 81% to 88% of par and (ii) 4.50% senior notes at a bid range of 80% to 87% of par (collectively, the “Tender Offer”). The Tender Offer included a tender premium of 5% of par for holders who tendered their senior notes prior to 5:00 p.m., New York City time, on July 11, 2022 (the “Tender Premium”). On July 26, 2022, the Company settled the Tender Offer and purchased $139.8 in aggregate principal amount, or approximately 8%, of its outstanding 4.625% senior notes at 87% of par, including the Tender Premium, and $381.8 in aggregate principal amount, or approximately 22%, of its outstanding 4.50% senior notes at 86% of par, including the Tender Premium, for aggregate cash consideration of $450.0, excluding accrued interest and fees. The Company paid tender fees of $1.7 in connection with the Tender Offer, which were included in “(Gain) loss on extinguishment of debt, net” in the Consolidated Statement of Operations for the year ended September 30, 2022 . The following table presents the Company’s cash repayments of debt, net of discounts included in the Consolidated Statements of Cash Flows and associated gain or loss included in “(Gain) loss on extinguishment of debt, net” in the Consolidated Statements of Operations. Cash repayments of debt (Gain) Loss on Extinguishment of Debt, net Year Ended Issuance Principal Amount Repaid Debt Discounts (Received) / Premiums Paid Write-off of Debt Issuance Costs / Write-off of Unamortized Premium 4.50% senior notes $ 529.5 $ (74.7) $ 6.0 $ — 4.625% senior notes 167.8 (21.9) 1.1 (1.8) 5.50% senior notes maturing in 2029 15.0 (1.2) 0.1 (0.2) 5.75% senior notes 840.0 24.1 5.0 (13.3) Second Incremental Term Loan 107.7 — — — Municipal bond 1.1 — — — 2022 Total $ 1,661.1 $ (73.7) $ 12.2 $ (15.3) 5.00% senior notes $ 1,697.3 $ 74.3 $ 18.9 $ — Municipal bond 1.0 — — — 2021 Total $ 1,698.3 $ 74.3 $ 18.9 $ — Term Loan $ 1,309.5 $ — $ 9.1 $ — 5.50% senior notes maturing in 2025 1,000.0 41.3 8.7 — Revolving Credit Facility 500.0 — — — 8.00% senior notes 122.2 8.5 0.7 — Municipal bond 1.1 — — — Credit Agreement — — 0.8 — 2020 Total $ 2,932.8 $ 49.8 $ 19.3 $ — The following table presents the Company’s non-cash repayments of debt, which are not included in the Consolidated Statements of Cash Flows, and the associated gain or loss included in “(Gain) loss on extinguishment of debt, net” in the Consolidated Statements of Operations. There were no non-cash repayments of debt for the year ended September 30, 2021. Non-cash repayments of debt (Gain) Loss on Extinguishment of Debt, net Year Ended Issuance Principal Amount Repaid Debt Discounts (Received) / Premiums Paid Write-off of Debt Issuance Costs Write-off of Unamortized Premium First Incremental Term Loan $ 840.0 $ — $ 3.5 $ — Second Incremental Term Loan 342.3 — 0.7 — 2022 Total $ 1,182.3 $ — $ 4.2 $ — 2020 Bridge Loan $ 1,225.0 $ — $ 3.8 $ — 2020 Total $ 1,225.0 $ — $ 3.8 $ — As of September 30, 2022, expected principal payments on the Company’s debt for the next five fiscal years were: September 30, 2022 Fiscal 2023 $ 1.1 Fiscal 2024 1.1 Fiscal 2025 1.2 Fiscal 2026 1.2 Fiscal 2027 (a) 1,035.6 (a) Includes principal payments of $575.0 related to the Company’s 2.50% convertible senior notes. Estimated future interest payments on the Company’s debt through fiscal 2027 are expected to be $1,395.6 (with $284.1 expected in fiscal 2023) based on interest rates as of September 30, 2022. Debt Covenants Under the terms of the Credit Agreement, the Company is required to comply with a financial covenant consisting of a secured net leverage ratio (as defined in the Credit Agreement) not to exceed 4.25:1.00, measured as of the last day of any fiscal quarter, if, as of the last day of such fiscal quarter, the aggregate outstanding amount of all revolving credit loans, swing line loans and letter of credit obligations (subject to certain exceptions specified in the Credit Agreement) exceeds 30% of the Company’s revolving credit commitments. As of September 30, 2022, the Company was not required to comply with such financial covenant as the aggregate amount of the aforementioned obligations did not exceed 30% of the Company’s revolving credit commitments. The Credit Agreement provides for incremental revolving and term loan facilities, and also permits other secured or unsecured debt, if, among other conditions, certain financial ratios are met, as defined and specified in the Credit Agreement.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Legal Proceedings Antitrust Claims In late 2008 and early 2009, approximately 22 class action lawsuits were filed in various federal courts against Michael Foods, Inc. (“MFI”), a wholly-owned subsidiary of the Company, and approximately 20 other defendants (producers of shell eggs and egg products and egg industry organizations), alleging violations of federal and state antitrust laws in connection with the production and sale of shell eggs and egg products, and seeking unspecified damages. All cases were transferred to the Eastern District of Pennsylvania for coordinated and/or consolidated pretrial proceedings. The cases involved three plaintiff groups: (i) a nationwide class of direct purchasers of shell eggs (the “direct purchaser class”); (ii) individual companies (primarily large grocery chains and food companies that purchase considerable quantities of eggs) that opted out of various settlements and filed their own complaints related to their purchases of shell eggs and egg products (the “opt-out plaintiffs”); and (iii) indirect purchasers of shell eggs (the “indirect purchaser plaintiffs”). Resolution of claims prior to fiscal 2022: Prior to fiscal 2022, MFI resolved the following claims, including all class claims: (i) in December 2016, MFI settled all claims asserted against it by the direct purchaser class for a payment of $75.0, which was approved by the district court in December 2017; (ii) in January 2017, MFI settled all claims asserted against it by opt-out plaintiffs related to shell egg purchases on confidential terms; (iii) in June 2018, MFI settled all claims asserted against it by indirect purchaser plaintiffs on confidential terms; and (iv) between June 2019 and September 2019, MFI individually settled on confidential terms egg product opt-out claims asserted against it by four separate opt-out plaintiffs. Fiscal 2022: During September 2022, MFI settled the remaining pending claims for this matter on confidential terms, which had sought damages based on purchases of egg products by three opt-out plaintiffs. MFI has at all times denied liability in this matter, and no settlement contains any admission of liability by MFI. During the year ended September 30, 2022, the Company expensed $13.8 related to the September 2022 settlement, which was included in “Selling, general and administrative expenses” in the Consolidated Statement of Operations. No expense was recorded in the years ended September 30, 2021 or 2020 related to these matters. At September 30, 2021, the Company had accrued $3.5 for this matter, which was included in “Other current liabilities” on the Consolidated Balance Sheet. The Company had no accrual related to this matter as of September 30, 2022 as the settlement was paid prior to year end. Under current law, any settlement paid, including the settlements with the direct purchaser plaintiffs, the opt-out plaintiffs and the indirect purchaser plaintiffs, is deductible for federal income tax purposes. Other The Company is subject to various other legal proceedings and actions arising in the normal course of business. In the opinion of management, based upon the information presently known, the ultimate liability, if any, arising from such pending legal proceedings, as well as from asserted legal claims and known potential legal claims which are likely to be asserted, taking into account established accruals for estimated liabilities (if any), are not expected to be material individually or in the aggregate to the consolidated financial condition, results of operations or cash flows of the Company. In addition, although it is difficult to estimate the potential financial impact of actions regarding expenditures for compliance with regulatory matters, in the opinion of management, based upon the information currently available, the ultimate liability arising from such compliance matters is not expected to be material to the consolidated financial condition, results of operations or cash flows of the Company. Bob Evans Lease Guarantees Historically, Bob Evans Farms, Inc. (“Bob Evans”) guaranteed certain payment and performance obligations associated with the leases for 143 properties (the “Guarantees”) leased by the restaurant business formerly owned by Bob Evans (the “Bob Evans Restaurant Business”). The Guarantees remained in effect following the Company’s acquisition of Bob Evans in 2018, but have subsequently been adjusted to 130 properties. In the event the Bob Evans Restaurant Business fails to meet its payment and performance obligations under these leases, subject in certain cases to certain early termination allowances, the Company may be required to make rent and other payments to the landlord under the requirements of the Guarantees. Should the Company, as guarantor of the lease obligations, be required to make all lease payments due for the remaining term of the leases subsequent to September 30, 2022, the maximum amount the Company may be required to pay is equal to the annual rent amount for the remainder of the lease terms. The current annual rent on these leases is $12.9 and will increase up to 1.5% annually based on indexed inflation. The lease terms for the majority of the leases extend for approximately 15 years from September 30, 2022, and the Guarantees would remain in effect in the event the leases are extended for a renewal period. In the event the Company is obligated to make payments under any of the Guarantees, the Company believes its exposure is limited due to protections and recourse available in the leases associated with the leased properties, including a requirement of the landlord to mitigate damages by re-letting the properties in default. While the COVID-19 pandemic impacted the restaurants industry generally, including the Bob Evans Restaurant Business, the Bob Evans Restaurant Business was able to amend certain of its leases during fiscal 2020 in order to ensure that it continued to meet its obligations under these leases, and there is no indication that the obligations will not continue to be met. As such, the Company believes the fair value of the Guarantees is immaterial as of September 30, 2022.

Pension and Other Postretiremen

Pension and Other Postretirement Benefits	12 Months Ended
	Sep. 30, 2022
Pension and Other Postretirement Benefits Cost (Reversal of Cost) [Abstract]
Pension and Other Postretirement Benefits	PENSION AND OTHER POSTRETIREMENT BENEFITSThe Company maintains qualified defined benefit plans in the U.S., the U.K. and Canada for certain employees primarily within its Post Consumer Brands and Weetabix segments. Certain of the Company’s employees are eligible to participate in the Company’s postretirement benefit plans (partially subsidized retiree health and life insurance). The following disclosures reflect amounts related to the Company’s employees based on separate actuarial valuations, projections and certain allocations. Amounts for the Canadian plans are included in the North America disclosures and are not disclosed separately because they do not constitute a significant portion of the combined amounts. With respect to defined benefits for Canadian Post Consumer Brands employees, eligibility is frozen to new entrants and benefit accrual is frozen for salaried employees. With respect to defined benefits for U.S. Post Consumer Brands employees, eligibility is frozen to new employees and the benefit accrual is frozen for all administrative employees and certain production employees. The benefit accrual is frozen for salaried Weetabix North America employees in the U.S. With respect to Weetabix employees in the U.K. participating in the executive and group schemes of the defined benefit pension plans, the plans are closed to new entrants and the benefit accrual is frozen with respect to existing participants. Defined Benefit Pension Plans The following table provides a reconciliation of the changes in the pension plans’ benefit obligations and fair value of assets over the two year period ended September 30, 2022 and a statement of the funded status and amounts recognized on the Consolidated Balance Sheets as of September 30, 2022 and 2021. North America Other International Year Ended Year Ended 2022 2021 2022 2021 Change in benefit obligation Benefit obligation at beginning of year $ 133.3 $ 131.1 $ 821.3 $ 834.4 Service cost 4.3 3.9 — — Interest cost 3.5 3.2 15.7 15.2 Plan participants’ contributions 0.4 0.4 — — Prior service cost (a) — 0.5 — — Actuarial gain (38.9) (1.4) (251.6) (32.7) Business combinations — 0.5 — — Benefits paid (5.9) (5.8) (28.4) (34.7) Currency translation (1.2) 0.9 (135.9) 39.1 Benefit obligation at end of year $ 95.5 $ 133.3 $ 421.1 $ 821.3 Change in fair value of plan assets Fair value of plan assets at beginning of year $ 136.6 $ 121.5 $ 970.9 $ 993.2 Actual return on plan assets (27.1) 19.5 (273.0) (34.1) Employer contributions 0.4 0.2 — — Plan participants’ contributions 0.4 0.4 — — Benefits paid (5.9) (5.8) (28.4) (34.7) Currency translation (1.5) 0.8 (162.1) 46.7 Other — — (0.1) (0.2) Fair value of plan assets at end of year 102.9 136.6 507.3 970.9 Funded status $ 7.4 $ 3.3 $ 86.2 $ 149.6 Amounts recognized in assets or liabilities Other assets $ 7.7 $ 3.8 $ 86.2 $ 149.6 Other liabilities (0.3) (0.5) — — Net amount recognized $ 7.4 $ 3.3 $ 86.2 $ 149.6 Amounts recognized in accumulated OCI Net actuarial loss (gain) $ 5.0 $ 11.3 $ 40.2 $ (6.0) Prior service cost 0.6 0.7 10.7 11.1 Total $ 5.6 $ 12.0 $ 50.9 $ 5.1 Weighted-average assumptions used to determine benefit obligation Discount rate — U.S. plans 5.65 % 3.05 % n/a n/a Discount rate — Canadian plans 5.12 % 3.32 % n/a n/a Discount rate — Other international plans n/a n/a 5.15 % 2.05 % Rate of compensation increase — U.S. plans 3.00 % 3.00 % n/a n/a Rate of compensation increase — Canadian plans 2.75 % 2.75 % n/a n/a Rate of compensation increase — Other international plans n/a n/a 3.85 % 3.45 % (a) Amounts reported for the year ended September 30, 2021 represent the impact of fiscal 2020 union negotiations that were ratified subsequent to September 30, 2020. The fair value of plan assets for the North American and other international pension plans exceeded the accumulated benefit obligation at September 30, 2022 and 2021. The aggregate accumulated benefit obligation for the North American pension plans was $94.6 and $130.8 at September 30, 2022 and 2021, respectively. The aggregate accumulated benefit obligation for the other international pension plans was $418.9 and $817.8 at September 30, 2022 and 2021, respectively. The following tables provide the components of net periodic benefit cost for the pension plans including amounts recognized in OCI. For the years ended September 30, 2022, 2021 and 2020, service cost was reported in “Cost of goods sold” and “Selling, general and administrative expenses” and all other components of net periodic benefit cost were reported in “Other income, net” in the Consolidated Statements of Operations. North America Year Ended September 30, 2022 2021 2020 Components of net periodic benefit cost Service cost $ 4.3 $ 3.9 $ 4.3 Interest cost 3.5 3.2 3.7 Expected return on plan assets (7.0) (6.4) (6.4) Recognized net actuarial loss 1.6 2.4 1.8 Recognized prior service cost 0.1 0.1 0.1 Net periodic benefit cost $ 2.5 $ 3.2 $ 3.5 Weighted-average assumptions used to determine net benefit cost Discount rate — U.S. plans 3.05 % 3.01 % 3.32 % Discount rate — Canadian plans 3.32 % 2.71 % 2.84 % Rate of compensation increase — U.S. plans 3.00 % 3.00 % 3.00 % Rate of compensation increase — Canadian plans 2.75 % 2.75 % 2.75 % Expected return on plan assets — U.S. plans 5.75 % 5.40 % 5.53 % Expected return on plan assets — Canadian plans 5.25 % 5.25 % 5.75 % Changes in plan assets and benefit obligation recognized in total comprehensive income Net (gain) loss $ (4.7) $ (14.5) $ 6.6 Recognized loss (1.6) (2.4) (1.8) Prior service cost (a) — 0.5 — Recognized prior service cost (0.1) (0.1) (0.1) Total recognized in OCI (before tax effects) $ (6.4) $ (16.5) $ 4.7 (a) Amounts reported for the year ended September 30, 2021 represent the impact of fiscal 2020 union negotiations that were ratified subsequent to September 30, 2020. Other International Year Ended September 30, 2022 2021 2020 Components of net periodic benefit cost Interest cost $ 15.7 $ 15.2 $ 14.7 Expected return on plan assets (24.8) (24.9) (24.6) Recognized prior service cost 0.4 0.5 — Net periodic benefit income $ (8.7) $ (9.2) $ (9.9) Weighted-average assumptions used to determine net benefit cost Discount rate 2.05 % 1.73 % 1.84 % Rate of compensation increase 3.45 % 2.65 % 2.55 % Expected return on plan assets 2.73 % 2.38 % 2.53 % Changes in plan assets and benefit obligation recognized in total comprehensive income Net loss $ 46.2 $ 26.4 $ 14.2 Prior service cost (a) — — 11.4 Recognized prior service cost (0.4) (0.5) — Total recognized in OCI (before tax effects) $ 45.8 $ 25.9 $ 25.6 (a) During the year ended September 30, 2020, the Company recognized prior service cost as a result of an amendment to the benefit plan for Weetabix employees in the U.K. participating in the group scheme. The Company expects to make contributions of $0.3 and zero to its defined benefit North American and other international pension plans, respectively, during fiscal 2023. The expected return on North American pension plan assets was determined based on historical and expected future returns of the various asset classes, using the target allocation. The broad target allocations are 58.1% equity securities, 37.8% fixed income and bonds, 3.4% real assets and 0.7% cash and cash equivalents. At September 30, 2022, equity securities were 54.5%, fixed income and bonds were 33.9%, real assets were 2.9% and cash and cash equivalents were 8.7% of the fair value of total plan assets, 91.9% of which was invested in passive index funds. At September 30, 2021, equity securities were 61.4%, fixed income and bonds were 34.4%, real assets were 1.8% and cash and cash equivalents were 2.4% of the fair value of total plan assets, 97.8% of which was invested in passive index funds. The allocation guidelines were established based on management’s determination of the appropriate risk posture and long-term objectives. The expected return on other international pension plan assets was determined based on historical and expected future returns of the various asset classes, using the target allocation. The broad target allocations are 71.7% fixed income and bonds, 27.6% liability driven investments, 0.5% real assets and 0.2% cash and cash equivalents. At September 30, 2022, fixed income and bonds were 78.8%, liability driven investments were 18.7%, real assets were 0.4% and cash and cash equivalents were 2.1% of the fair value of total plan assets, 20.2% of which was invested in passive index funds. At September 30, 2021, fixed income and bonds were 72.6%, liability driven investments were 24.3%, real assets were 1.0% and cash and cash equivalents were 2.1% of the fair value of total plan assets, 31.3% of which was invested in passive index funds. The allocation guidelines were established by the trustees of the plan based on their determination of the appropriate risk posture and long-term objectives after consulting with management. The following tables present the North American and other international pension plans’ assets measured at fair value on a recurring basis and the basis for that measurement. The fair value of funds is based on quoted net asset values of the shares held by the plans at year end. North America September 30, 2022 September 30, 2021 Total Level 1 Level 2 Total Level 1 Level 2 Equities $ 11.0 $ — $ 11.0 $ 13.8 $ — $ 13.8 Fixed income and bonds 5.0 — 5.0 5.7 — 5.7 Cash and cash equivalents 8.9 8.9 — 3.4 3.4 — Fair value of plan assets in the fair value hierarchy 24.9 8.9 16.0 22.9 3.4 19.5 Equities 45.1 — — 70.1 — — Fixed income and bonds 29.9 — — 41.2 — — Real assets 3.0 — — 2.4 — — Investments measured at net asset value (a) 78.0 — — 113.7 — — Total plan assets $ 102.9 $ 8.9 $ 16.0 $ 136.6 $ 3.4 $ 19.5 Other International September 30, 2022 September 30, 2021 Total Level 1 Level 2 Total Level 1 Level 2 Fixed income and bonds $ 321.3 $ 321.3 $ — $ 649.3 $ 649.3 $ — Liability driven instruments 77.9 77.9 — 206.4 206.4 — Cash and cash equivalents 10.6 10.6 — 17.8 17.8 — Fair value of plan assets in the fair value hierarchy 409.8 409.8 — 873.5 873.5 — Fixed income and bonds 78.5 — — 56.1 — — Liability driven instruments 16.9 — — 29.3 — — Real assets 2.1 — — 9.5 — — Cash and cash equivalents — — — 2.5 — — Investments measured at net asset value (a) 97.5 — — 97.4 — — Total plan assets $ 507.3 $ 409.8 $ — $ 970.9 $ 873.5 $ — (a) In accordance with ASC Topic 820, certain investments were measured at NAV. In cases where the fair value was measured at NAV using the practical expedient provided for in ASC Topic 820, the investments have not been classified in the fair value hierarchy. The fair value amounts presented in these tables are intended to permit reconciliation of the fair value hierarchy to the tables above. Other Postretirement Benefits The following table provides a reconciliation of the changes in the North American other postretirement benefit obligations over the two year period ended September 30, 2022. Besides the North American plans, the Company does not maintain any other postretirement benefit plans. Year Ended 2022 2021 Change in benefit obligation Benefit obligation at beginning of year $ 66.5 $ 70.7 Service cost 0.5 0.5 Interest cost 1.5 1.5 Actuarial gain (17.4) (4.3) Benefits paid (2.3) (2.4) Currency translation (0.5) 0.5 Benefit obligation at end of year $ 48.3 $ 66.5 Change in fair value of plan assets Employer contributions 2.3 2.4 Benefits paid (2.3) (2.4) Fair value of plan assets at end of year — — Funded status $ (48.3) $ (66.5) Amounts recognized in assets or liabilities Other current liabilities (3.0) (2.8) Other liabilities (45.3) (63.7) Net amount recognized $ (48.3) $ (66.5) Amounts recognized in accumulated OCI Net actuarial loss $ (9.2) $ 8.9 Prior service credit (5.4) (10.0) Total $ (14.6) $ (1.1) Weighted-average assumptions used to determine benefit obligation Discount rate — U.S. plans 5.62 % 2.89 % Discount rate — Canadian plans 5.12 % 3.45 % Rate of compensation increase — Canadian plans 2.75 % 2.75 % The following table provides the components of net periodic benefit cost for the other postretirement benefit plans including amounts recognized in OCI. For the years ended September 30, 2022, 2021 and 2020, service cost was reported in “Cost of goods sold” and “Selling, general and administrative expenses” and all other components of net periodic benefit cost were reported in “Other income, net” in the Consolidated Statements of Operations. Year Ended September 30, 2022 2021 2020 Components of net periodic benefit cost Service cost $ 0.5 $ 0.5 $ 0.6 Interest cost 1.5 1.5 1.9 Recognized net actuarial loss 0.6 1.1 0.6 Recognized prior service credit (4.6) (4.7) (4.7) Net periodic benefit cost $ (2.0) $ (1.6) $ (1.6) Weighted-average assumptions used to determine net benefit cost Discount rate — U.S. plans 2.89 % 2.79 % 3.20 % Discount rate — Canadian plans 3.45 % 2.78 % 2.86 % Rate of compensation increase — Canadian plans 2.75 % 2.75 % 2.75 % Changes in benefit obligation recognized in total comprehensive income Net (gain) loss $ (17.5) $ (4.3) $ 4.6 Recognized net actuarial loss (0.6) (1.1) (0.6) Recognized prior service credit 4.6 4.7 4.7 Total recognized in OCI (before tax effects) $ (13.5) $ (0.7) $ 8.7 For September 30, 2022 measurement purposes, the assumed annual rate of increase in the future per capita cost of covered health care benefits related to domestic plans for 2023 was 6.3% for participants both under the age of 65 and over the age of 65, declining gradually to an ultimate rate of 5.0% for 2028 and beyond. For September 30, 2021 measurement purposes, the assumed annual rate of increase in the future per capita cost of covered health care benefits related to domestic plans for 2022 was 5.9% for participants both under the age of 65 and over the age of 65, declining gradually to an ultimate rate of 5.0% for 2026 and beyond. For both September 30, 2022 and 2021 measurement purposes, the assumed annual rate of increase in the future per capita cost of covered health care benefits related to Canadian plans for the following fiscal year was 4.5%, and will remain at this rate for 2023 and beyond. Additional Information As of September 30, 2022, expected future benefit payments and related federal subsidy receipts (Medicare Part D) in the next ten fiscal years were as follows: 2023 2024 2025 2026 2027 2028 - 2032 Pension benefits $ 24.3 $ 24.8 $ 25.9 $ 27.1 $ 28.2 $ 156.2 Other benefits 3.2 3.4 3.4 3.4 3.5 17.9 Subsidy receipts 0.1 0.1 0.1 0.2 0.2 1.1

Stock-Based Compensation Plans

Stock-Based Compensation Plans	12 Months Ended
	Sep. 30, 2022
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	STOCK-BASED COMPENSATION Long-Term Incentive Plans The Company’s employees participate in various Company long-term incentive plans (the “Long-Term Incentive Plans”). On January 27, 2022, the Company’s shareholders approved the 2021 Long-Term Incentive Plan (the “2021 Plan”), which permits the issuance of stock-based compensation awards of up to 2.4 million shares, plus shares remaining to be issued under the 2019 Long-Term Incentive Plan (including any shares assumed thereunder from the 2016 and 2012 Long-Term Incentive Plans) which were transferred to the 2021 Plan upon its effectiveness. Awards issued under the Long-Term Incentive Plans have a maximum term of 10 years. At September 30, 2022, there were 1.8 million shares remaining to be issued for stock-based compensation awards under the 2021 Plan. Total compensation cost for the Company’s cash and non-cash stock-based compensation awards recognized in the years ended September 30, 2022, 2021 and 2020 was $66.4, $49.7 and $43.2, respectively, and the related recognized deferred tax benefit for each of those periods was approximately $9.1, $5.8 and $6.0, respectively. As of September 30, 2022, the total compensation cost related to Post’s non-vested awards not yet recognized was $78.5, which is expected to be recognized over a weighted-average period of 1.3 years. BellRing Spin-off Impact In connection with the BellRing Spin-off, adjustments were made to the terms of outstanding equity-based awards (the “Equity Awards”) to preserve the intrinsic value of the Equity Awards and to participants’ accounts under the deferred compensation plans maintained by the Company with respect to notional investments in Post common stock (the “Deferred Compensation Accounts”). The adjustments to the Equity Awards and Deferred Compensation Accounts were based on the volume weighted average price of a share of Post common stock during the five trading day period prior to and including March 10, 2022 and the volume weighted average price of a share of Post common stock during the five trading day period immediately following March 10, 2022. In addition, certain market-based performance restricted stock units granted in fiscal 2020 to named executive officers of Post pursuant to the 2019 Long-Term Incentive Plan that were outstanding as of immediately prior to the BellRing Spin-off (the “Fiscal 2020 Market PRSUs”) were converted into a number of time-based restricted stock units based on achievement of Post’s total shareholder return ranking compared to such rankings of peer companies over a specified performance period ending on March 10, 2022. The vesting of the converted Fiscal 2020 Market PRSUs was subject to the requirement to remain employed through October 15, 2022, and otherwise remained subject to the terms and restrictions of the applicable award agreements. The adjustments to the Equity Awards had an immaterial impact on the Company’s Consolidated Statement of Operations for the year ended September 30, 2022. The disclosures regarding the Company’s equity arrangements below include certain awards issued to BellRing employees in Post common stock prior to the BellRing IPO and still outstanding at the beginning of fiscal 2022. Stock Appreciation Rights (“SARs”) in millions, except SARs or where otherwise indicated SARs Weighted- Weighted- Aggregate Outstanding at September 30, 2021 95,000 $ 46.59 Granted — Impact of BellRing Spin-off 41,038 33.62 Exercised (54,484) 31.22 Forfeited — Expired — Outstanding at September 30, 2022 81,554 33.42 1.64 $ 4.0 Vested and expected to vest as of September 30, 2022 81,554 33.42 1.64 4.0 Exercisable at September 30, 2022 81,554 33.42 1.64 4.0 (a) The weighted-average exercise price per share for activity subsequent to the BellRing Spin-off, including the outstanding balance as of September 30, 2022, reflects the adjustment to preserve the intrinsic value of the Equity Awards outstanding immediately prior to the BellRing Spin-off. Upon exercise of each SAR, the holder will receive the number of shares of Post common stock equal in value to the difference between the exercise price and the fair market value at the date of exercise, less all applicable taxes. The total intrinsic value of SARs exercised was $3.0, $3.2 and $0.1 during the years ended September 30, 2022, 2021 and 2020, respectively. There were no SARs granted during the years ended September 30, 2022, 2021 or 2020. Stock Options in millions, except stock options or where otherwise indicated Stock Options Weighted- Weighted- Aggregate Outstanding at September 30, 2021 889,096 $ 65.67 Granted — — Impact of BellRing Spin-off 353,559 48.89 Exercised (231,340) 39.28 Forfeited — — Expired — — Outstanding at September 30, 2022 1,011,315 48.75 4.34 $ 33.5 Vested and expected to vest as of September 30, 2022 1,011,315 48.75 4.34 33.5 Exercisable at September 30, 2022 996,235 48.40 4.30 33.4 (a) The weighted-average exercise price per share for activity subsequent to the BellRing Spin-off, including the outstanding balance as of September 30, 2022, reflects the adjustment to preserve the intrinsic value of the Equity Awards outstanding immediately prior to the BellRing Spin-off. The fair value of each stock option was estimated on the date of grant using the Black-Scholes Model. The Company used the simplified method for estimating a stock option term as it did not have sufficient historical stock option exercise experience upon which to estimate an expected term. The expected term was estimated based on the award’s vesting period and contractual term. Expected volatilities were based on historical volatility trends and other factors. The risk-free rate was the interpolated U.S. Treasury rate for a term equal to the expected term. The weighted-average assumptions and fair values for stock options granted during the year ended September 30, 2020 are summarized in the table below. There were no stock options granted during the years ended September 30, 2022 and 2021. Expected term (in years) 6.5 Expected stock price volatility 29.2% Risk-free interest rate 1.8% Expected dividends 0% Fair value (per stock option) $35.32 The total intrinsic value of stock options exercised was $14.1, $46.4 and $5.5 in the years ended September 30, 2022, 2021 and 2020, respectively. The Company received proceeds from the exercise of stock options of $4.9, $7.6 and $3.9 during the years ended September 30, 2021, 2021 and 2020, respectively. Restricted Stock Units (“RSUs”) RSUs Weighted- Nonvested at September 30, 2021 822,112 $ 97.23 Granted 432,538 102.58 Impact of BellRing Spin-off (b) 520,090 n/a Vested (361,026) 91.68 Forfeited (64,908) 81.63 Nonvested at September 30, 2022 1,348,806 68.38 (a) The weighted-average grant date fair value for the activity subsequent to the BellRing Spin-off, including the nonvested balance as of September 30, 2022, reflects the adjustment to preserve the intrinsic value of the Equity Awards outstanding immediately prior to the BellRing Spin-off. (b) The Impact of BellRing Spin-off includes the adjustments to preserve the intrinsic value of the Equity Awards outstanding immediately prior to the BellRing Spin-off and the incremental RSUs from conversion of the Fiscal 2020 Market PRSUs. The grant date fair value of each RSU award was determined based upon the closing price of the Company’s common stock on the date of grant. The weighted-average grant date fair value of nonvested RSUs was $68.38, $97.23 and $89.14 at September 30, 2022, 2021 and 2020, respectively. The total vest date fair value of RSUs that vested during fiscal 2022, 2021 and 2020 was $35.1, $49.8 and $42.1, respectively. Cash-Settled Restricted Stock Units (“Cash RSUs”) Cash RSUs Weighted- Nonvested at September 30, 2021 29,400 $ 51.43 Granted — — Impact of BellRing Spin-off 14,193 n/a Vested (14,530) 34.68 Forfeited — — Nonvested at September 30, 2022 29,063 34.68 (a) The weighted-average grant date fair value for the activity subsequent to the BellRing Spin-off, including the nonvested balance as of September 30, 2022, reflects the adjustment to preserve the intrinsic value of the Equity Awards outstanding immediately prior to the BellRing Spin-off. At September 30, 2022, the 29,063 nonvested Cash RSUs were valued at the greater of the closing stock price or the grant price adjusted for the BellRing Spin-off of $34.68. Cash used by the Company to settle Cash RSUs was $1.1, $1.1 and $0.9 for the years ended September 30, 2022, 2021 and 2020, respectively. Earnings-Based Performance Restricted Stock Units (“Earnings PRSUs”) Earnings PRSUs Weighted- Nonvested at September 30, 2021 7,526 $ 98.33 Granted 195,533 104.74 Impact of BellRing Spin-off 96,177 n/a Adjustment for performance achievement (b) (12,588) n/a Vested — — Forfeited (14,221) 78.27 Nonvested at September 30, 2022 272,427 70.46 (a) The weighted-average grant date fair value for the activity subsequent to the BellRing Spin-off, including the nonvested balance as of September 30, 2022, reflects the adjustment to preserve the intrinsic value of the Equity Awards outstanding immediately prior to the BellRing Spin-off. (b) Represents the adjustment to previously granted Earnings PRSUs for performance achievement. During the years ended September 30, 2022 and 2021, the Company granted Earnings PRSUs to certain employees. These awards will be earned based on reaching certain earnings-based targets over a period ranging from one to three years. The grant date fair value of each Earnings PRSU award was determined based upon the closing price of the Company’s common stock on the date of grant and the assumption that the Company would meet the full earnings-based targets. The Company reassesses the probability of achieving the earnings-based targets each quarterly reporting period and adjusts compensation cost accordingly. The weighted-average grant date fair value of nonvested Earnings PRSUs was $70.46 and $98.33 at September 30, 2022 and 2021, respectively. There were no Earnings PRSUs granted during the year ended September 30, 2020, and there were no Earnings PRSUs vested during the years ended September 30, 2022, 2021 or 2020. Market-Based Performance Restricted Stock Units (“Market PRSUs”) Market PRSUs Weighted- Nonvested at September 30, 2021 285,335 $ 142.61 Granted 108,922 163.63 Impact of BellRing Spin-off (b) 62,114 n/a Adjustment for performance achievement (c) (19,508) n/a Vested (61,940) 122.34 Forfeited (521) 110.35 Nonvested at September 30, 2022 374,402 106.10 (a) The weighted-average grant date fair value for the activity subsequent to the BellRing Spin-off, including the nonvested balance as of September 30, 2022, reflects the adjustment to preserve the intrinsic value of the Equity Awards outstanding immediately prior to the BellRing Spin-off. (b) The Impact of BellRing Spin-off includes adjustments to preserve the intrinsic value of the Equity Awards outstanding immediately prior to the BellRing Spin-off, offset by the conversion of the Fiscal 2020 Market PRSUs into RSUs. (c) Represents the adjustment to previously granted Market PRSUs for performance achievement. The total vest date fair value of Market PRSUs that vested during fiscal 2022 and 2021 was $6.6 and $3.9, respectively. There were no Market PRSUs vested during the year ended September 30, 2020. During the years ended September 30, 2022, 2021 and 2020, the Company granted Market PRSUs to certain employees. As described above, the Fiscal 2020 Market PRSUs were converted into a number of time-based RSUs in connection with the BellRing Spin-off. The fiscal 2022 and 2021 Market PRSUs will be earned by comparing Post’s total shareholder return (“TSR”) during a three year period to the respective TSRs of companies in a performance peer group. Based upon Post’s ranking in its performance peer group when comparing TSRs, a recipient of a Market PRSU grant may earn a total award ranging from 0% to 260% of the target award. The fair value of each Market PRSU was estimated on the grant date using a Monte Carlo simulation. The assumptions for Market PRSUs granted during the years ended September 30, 2022, 2021 and 2020 are summarized in the table below. 2022 2021 2020 Expected term (in years) 3.0 3.0 3.0 Expected stock price volatility 27.7% 28.3% 22.2% Risk-free interest rate 0.9% 0.2% 1.6% Fair value (per Market PRSU) $163.63 $152.58 $138.10 Deferred Compensation Post provides deferred compensation plans for directors and key employees through which eligible participants may elect to defer payment of all or a portion of their compensation, or with respect to key employee participants, all or a portion of their eligible annual bonus, until a later date based on the participant’s elections. Participant deferrals for employee participants may be notionally invested in Post common stock equivalents (the “Equity Option”) or into a number of funds operated by The Vanguard Group Inc. with a variety of investment strategies and objectives (the “Vanguard Funds”). In order to receive a 33.3% matching contribution, deferrals for director participants must be made into the Equity Option. Deferrals into the Equity Option are generally distributed in Post stock for employees and cash for directors, while deferrals into the Vanguard Funds are distributed in cash. There are no significant costs related to the administration of the deferred compensation plans. Post funds its deferred compensation liability (potential cash distributions) by investing in the Vanguard Funds in substantially the same amounts as selected by the participating employees. Both realized and unrealized gains and losses on these investments are included in “Selling, general and administrative expenses” in the Consolidated Statements of Operations and offset the related change in the deferred compensation liability. For additional information regarding deferred compensation, refer to Note 14.

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Sep. 30, 2022
Stockholders' Equity Attributable to Parent [Abstract]
Shareholders' Equity	SHAREHOLDERS’ EQUITY The following table summarizes the Company’s repurchases of its common stock. September 30, 2022 2021 2020 Shares repurchased (in millions) 4.9 4.0 6.1 Average price per share including broker’s commissions (a) $ 90.04 $ 98.39 $ 97.67 Total cost including broker’s commissions (b) $ 439.0 $ 393.7 $ 587.8 (a) Average repurchase price per share including broker’s commissions during the year ended September 30, 2022 was $103.81 prior to the BellRing Spin-off and $81.54 subsequent to the BellRing Spin-off. (b) Of the $393.7 total cost recorded during the year ended September 30, 2021, $4.0 was not settled until October 2021 and was included in “Other current liabilities” on the Consolidated Balance Sheet at September 30, 2021. The Company may, from time to time, enter into common stock structured repurchase arrangements with financial institutions using general corporate funds. Under such arrangements, the Company pays a fixed sum of cash upon execution of each agreement in exchange for the right to receive either a predetermined amount of cash or Post common stock. Upon expiration of each agreement, if the closing market price of Post’s common stock is above the predetermined price, the Company will have the initial investment returned with a premium in cash. If the closing market price of Post’s common stock is at or below the predetermined price, the Company will receive the number of shares specified in the agreement. During the year ended September 30, 2020, the Company entered into a structured share repurchase arrangement which required cash payments totaling $46.4, which were recorded as “Cash paid for stock repurchase contracts” in the Consolidated Statement of Cash Flows for the year ended September 30, 2020. This arrangement settled during the year ended September 30, 2021, and the Company received cash payments of $47.5, which were recorded as “Additional paid-in-capital” on the Consolidated Balance Sheet at September 30, 2021 and as “Cash received from share repurchase contracts” in the Consolidated Statement of Cash Flows for the year ended September 30, 2021.

Segments

Segments	12 Months Ended
	Sep. 30, 2022
Segment Reporting [Abstract]
Segments	SEGMENTS At September 30, 2022, the Company managed and reported operating results through the following four reportable segments: • Post Consumer Brands: North American RTE cereal and Peter Pan nut butters; • Weetabix: primarily U.K. RTE cereal, muesli and protein-based RTD shakes; • Foodservice: primarily egg and potato products; and • Refrigerated Retail: primarily side dish, egg, cheese and sausage products. Due to the level of integration between the Foodservice and Refrigerated Retail segments, it is impracticable to present additions to property and intangibles and total assets separately for each segment. An allocation has been made between the two segments for depreciation based on inventory costing. Amounts reported for Corporate in the table below include any amounts attributable to PHPC. Management evaluates each segment’s performance based on its segment profit, which for all segments is its earnings/loss before income taxes and equity method earnings/loss before impairment of property, goodwill and other intangible assets, facility closure related costs, restructuring expenses, gain/loss on assets and liabilities held for sale, gain/loss on sale of businesses and facilities, gain on/adjustment to bargain purchase, interest expense and other unallocated corporate income and expenses. In fiscal 2022, 2021 and 2020, Post’s external revenues were primarily generated by sales within the U.S.; foreign sales were 12.5%, 14.3% and 14.5% of total net sales, respectively. The largest concentration of foreign sales was within the U.K., which accounted for 52.9%, 54.6% and 53.6% of total foreign sales in fiscal 2022, 2021 and 2020, respectively. Sales are attributed to individual countries based on the address to which the product is shipped. As of September 30, 2022 and 2021, the majority of Post’s tangible long-lived assets were located in the U.S.; the remainder were located primarily in the U.K. and Canada, which combined have a net carrying value of approximately $253.6 and $300.2, respectively. In the years ended September 30, 2022, 2021 and 2020, one customer, including its affiliates, accounted for 14.4%, 15.9% and 18.7%, respectively, of Post’s total net sales. All segments, except Foodservice, sold products to this major customer or its affiliates. The following tables present information about the Company’s reportable segments. In addition, the tables present net sales by product. Note that additions to property and intangibles exclude additions through business acquisitions (see Note 6). Year Ended September 30, 2022 2021 2020 Net Sales Post Consumer Brands $ 2,242.7 $ 1,915.3 $ 1,949.1 Weetabix 477.3 477.5 440.4 Foodservice 2,095.0 1,615.6 1,361.8 Refrigerated Retail 1,036.6 974.5 961.2 Eliminations and Corporate (0.4) (2.2) (1.5) Total $ 5,851.2 $ 4,980.7 $ 4,711.0 Segment Profit Post Consumer Brands $ 314.6 $ 316.6 $ 393.5 Weetabix 109.5 115.4 112.3 Foodservice 151.0 61.7 25.6 Refrigerated Retail 57.1 75.9 125.6 Total segment profit 632.2 569.6 657.0 General corporate expenses and other 196.8 52.6 109.0 Interest expense, net 317.8 332.6 333.9 (Gain) loss on extinguishment of debt, net (72.6) 93.2 72.9 (Income) expense on swaps, net (268.0) (122.8) 187.1 Gain on investment in BellRing (437.1) — — Earnings (loss) before income taxes and equity method loss $ 895.3 $ 214.0 $ (45.9) Net sales by product Cereal $ 2,595.0 $ 2,333.3 $ 2,388.7 Nut butters 111.7 58.7 — Eggs and egg products 2,026.1 1,556.1 1,307.8 Side dishes (including potato products) 652.4 575.0 536.6 Cheese and dairy 214.3 223.0 253.2 Sausage 171.2 165.9 168.1 Protein-based products 12.9 — — Other 68.5 70.9 58.1 Eliminations and Corporate (0.9) (2.2) (1.5) Total $ 5,851.2 $ 4,980.7 $ 4,711.0 Additions to property and intangibles Post Consumer Brands $ 91.2 $ 81.2 $ 67.4 Weetabix 26.7 19.6 24.6 Foodservice and Refrigerated Retail 136.1 89.7 139.5 Corporate (a) 20.8 0.4 1.0 Total $ 274.8 $ 190.9 $ 232.5 Depreciation and amortization Post Consumer Brands $ 133.1 $ 122.0 $ 112.4 Weetabix 37.5 39.0 35.9 Foodservice 127.5 126.0 119.6 Refrigerated Retail 78.4 75.5 73.1 Total segment depreciation and amortization 376.5 362.5 341.0 Corporate 3.7 4.0 4.0 Total $ 380.2 $ 366.5 $ 345.0 September 30, 2022 2021 Assets, end of year Post Consumer Brands $ 3,529.1 $ 3,467.8 Weetabix 1,591.3 1,930.4 Foodservice and Refrigerated Retail 5,022.7 5,074.2 Corporate 1,164.9 1,248.2 Total assets of continuing operations 11,308.0 11,720.6 Total assets of discontinued operations — 694.1 Total assets $ 11,308.0 $ 12,414.7 (a) During the year ended September 30, 2022, the Company had non-cash exchanges of fixed assets of $19.5, which were included in the Corporate additions to property and intangibles.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation — The consolidated financial statements include the operations of Post and its consolidated subsidiaries. All intercompany transactions have been eliminated.
Use of Estimates and Allocations	Use of Estimates and Allocations — The consolidated financial statements of the Company are prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”), which require certain elections as to accounting policy, estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent liabilities at the dates of the financial statements and the reported amount of net revenues and expenses during the reporting periods. Significant accounting policy elections, estimates and assumptions include, among others, allowance for trade promotions, business combinations, pension and benefit plan assumptions, valuation assumptions of goodwill and other intangible assets and income taxes. Actual results could differ from those estimates.
Business Combinations	Business Combinations — The Company uses the acquisition method of accounting for acquired businesses. Under the acquisition method, the Company’s financial statements reflect the operations of an acquired business starting from the completion of the acquisition. The assets acquired and liabilities assumed are recorded at their respective estimated fair values at the date of the acquisition. Any excess of the purchase price over the estimated fair values of the identifiable net assets acquired is recorded as goodwill. Any excess of the estimated fair values of the identifiable net assets acquired over the purchase price is recorded as a gain on bargain purchase.
Cash Equivalents	Cash Equivalents — Cash equivalents include all highly liquid investments with original maturities of less than three months.
Restricted Cash	Restricted Cash — Restricted cash includes items such as cash deposits which serve as collateral for certain commodity hedging contracts as well as the Company’s high deductible workers’ compensation insurance program.
Receivables	Receivables — Receivables are reported net of appropriate allowances for credit losses, cash discounts and other amounts which the Company does not ultimately expect to collect. To calculate an allowance for credit losses, the Company estimates uncollectible amounts based on a review of past due balances, historical loss information and an evaluation of customer accounts for potential future losses. A receivable is considered past due if payments have not been received within the agreed upon invoice terms. Receivables are written off against the allowance when the customer files for bankruptcy protection or are otherwise deemed to be uncollectible based upon the Company’s evaluation of the customer’s solvency. As of September 30, 2022 and 2021, the Company did not have off-balance sheet credit exposure related to its customers.
Inventories	Inventories — Inventories, other than flocks, are generally valued at the lower of average cost (determined on a first-in, first-out basis) or net realizable value. Reported amounts have been reduced by an allowance for obsolete product and packaging materials based on a review of inventories on hand compared to estimated future usage and sales. Flock inventory represents the cost of purchasing and raising chicken flocks to egg laying maturity. The costs included in our flock inventory include the costs of the chicks, the feed fed to the birds and the labor and overhead costs incurred to operate the pullet facilities until the birds are transferred into the laying facilities, at which time their cost is amortized to operations, as cost of goods sold, over their expected useful lives of one to two years.
Restructuring Expenses	Restructuring Expenses — Restructuring charges and related charges principally consist of one-time termination benefits, severance, contract termination benefits, accelerated stock compensation and other employee separation costs. The Company recognizes restructuring obligations and liabilities for exit and disposal activities at fair value in the period the liability is incurred. Employee severance costs are expensed when they become probable and reasonably estimable under established severance plans.
Property	Property — Property is recorded at cost, and depreciation expense is generally provided on a straight-line basis over the estimated useful lives of the properties. Estimated useful lives range from 1 to 29 years for machinery and equipment; 1 to 35 years for buildings, building improvements and leasehold improvements; and 1 to 7 years for software. Total depreciation expense was $232.9, $222.2 and $206.7 in fiscal 2022, 2021 and 2020, respectively. Any gains and losses incurred on the sale or disposal of assets are included in “Other operating expense (income), net” in the Consolidated Statements of Operations. Repair and maintenance costs incurred in connection with ongoing and planned major maintenance activities are accounted for under the direct expensing method.
Goodwill	Goodwill represents the excess of the purchase price of acquired businesses over the fair market value of their identifiable net assets. The Company conducts a goodwill impairment assessment during the fourth quarter of each fiscal year following the annual forecasting process, or more frequently if facts and circumstances indicate that goodwill may be impaired. The goodwill impairment assessment performed may be either qualitative or quantitative; however, if adverse qualitative trends are identified that could negatively impact the fair value of the business, a quantitative goodwill impairment test is performed. In fiscal 2022, 2021 and 2020, the Company performed a quantitative impairment test for all reporting units. The estimated fair value is determined using a combined income and market approach with a greater weighting on the income approach. The income approach is based on discounted future cash flows and requires significant assumptions, including estimates regarding future revenue, profitability, capital requirements and discount rates. The market approach is based on a market multiple (revenue and EBITDA) and requires an estimate of appropriate multiples based on market data for comparable peers.
Other Intangible Assets	Other Intangible Assets — Other intangible assets consist primarily of customer relationships, trademarks and brands acquired in business combinations and include both indefinite and definite-lived assets.
Recoverability of Assets	Recoverability of Assets — The Company continually evaluates whether events or circumstances have occurred which might impair the recoverability of the carrying value of its assets, including property, identifiable intangibles and right-of-use (“ROU”) assets. Trademarks with indefinite lives are reviewed for impairment during the fourth quarter of each fiscal year following the annual forecasting process, or more frequently if facts and circumstances indicate the trademark may be impaired. The trademark impairment test performed may either be qualitative or quantitative; however, if adverse qualitative trends are identified that could negatively impact the fair value of the trademark, a quantitative impairment test is performed. In fiscal 2022, 2021 and 2020, the Company performed a quantitative impairment test. The quantitative trademark impairment tests require the Company to compare the calculated fair value of the trademark to its carrying value. If the carrying value of the intangible asset exceeds its fair value, an impairment loss is recognized in an amount equal to that excess. The fair value is determined using an income-based approach, which requires significant assumptions for each brand, including estimates regarding future revenue growth, discount rates and royalty rates. Assumptions are determined after consideration of several factors for each brand, including profit levels, research of external royalty rates by third party experts and the relative importance of each brand to the Company. Revenue growth assumptions are based on historical trends and management’s expectations for future growth by brand. The discount rate is based on a weighted-average cost of capital utilizing industry market data of similar companies. The Company conducted impairment reviews and concluded there were no impairments of any indefinite-lived assets during the years ended September 30, 2022, 2021 or 2020. These fair value measurements fall within Level 3 of the fair value hierarchy as described in Note 14. In addition, definite-lived assets (groups) are tested for recoverability when events or changes in circumstances indicate that the carrying value of an asset (group) may not be recoverable or the estimated useful life is no longer appropriate. The Company groups assets at the lowest level for which cash flows are separately identifiable. In general, an asset (group) is deemed impaired and written down to its fair value if the estimated related undiscounted future cash flows are less than its carrying amount. There were no indicators, including adverse trends in the business, that indicated that the carrying value of the Company’s definite-lived assets (groups) were not recoverable in fiscal 2022, 2021 or 2020.
Deferred Compensation Investments	Deferred Compensation Investments — The Company funds a portion of its deferred compensation liability by investing in certain mutual funds in substantially the same amounts as selected by the participating employees. Because management’s intent is to invest in a manner that matches the deferral options chosen by the participants and those participants can elect to transfer amounts into or out of each of the designated deferral options at any time, these investments are stated at fair value in “Prepaid expenses and other current assets” and “Other assets” on the Consolidated Balance Sheets (see Note 14). Both realized and unrealized gains and losses on these assets are included in “Selling, general and administrative expenses” in the Consolidated Statements of Operations and offset the related change in the deferred compensation liability.
Derivatives	Derivative Financial Instruments — In the ordinary course of business, the Company is exposed to commodity price risks relating to the purchases of raw materials and supplies, interest rate risks relating to variable rate debt and foreign currency exchange rate risks. The Company utilizes derivative financial instruments, including (but not limited to) futures contracts, option contracts, forward contracts and swaps, to manage certain of these exposures by hedging when it is practical to do so. The Company does not hold or issue financial instruments for speculative or trading purposes. The Company’s derivative programs may include strategies that qualify and strategies that do not qualify for hedge accounting treatment. To qualify for hedge accounting, the hedging relationship, both at inception of the hedge and on an ongoing basis, is expected to be highly effective in achieving offsetting changes in the fair value of the hedged risk during the period that the hedge is designated. All derivatives are recognized on the balance sheet at fair value. For derivatives that qualify for hedge accounting, the derivative is designated as a hedge on the date in which the derivative contract is entered. A derivative could be designated as a hedge of a forecasted transaction or of the variability of cash flows to be received or paid related to a recognized asset or liability (cash flow hedge) or a hedge of a net investment in a foreign operation. Some derivatives may also be considered natural hedging instruments, where changes in their fair value act as economic offsets to changes in fair value of the underlying hedged item and are not designated for hedge accounting.
Leases	Leases — The Company leases office space, certain warehouses and equipment primarily through operating lease agreements. The Company has no material finance lease agreements. The Company determines if an arrangement is a lease at its inception. When the arrangements include lease and non-lease components, the Company accounts for them as a single lease component. Leases with an initial term of less than 12 months are not reported on the balance sheet, but rather are recognized as lease expense on a straight-line basis over the lease term. Arrangements may include options to extend or terminate the lease arrangement. These options are included in the lease term used to establish ROU assets and lease liabilities when it is reasonably certain they will be exercised. The Company will reassess expected lease terms based on changes in circumstances that indicate options may be more or less likely to be exercised. The Company has certain lease arrangements that include variable rental payments. The future variability of these payments and adjustments are unknown and therefore are not included in minimum rental payments used to determine ROU assets and lease liabilities. The Company has lease arrangements where it makes separate payments to the lessor based on the lessor’s common area maintenance expenses, property and casualty insurance costs, property taxes assessed on the property and other variable expenses. As the Company has elected the practical expedient not to separate lease and non-lease components, these variable amounts are captured in operating lease expense in the period in which they are incurred. Variable rental payments are recognized in the period in which their associated obligation is incurred. For lease arrangements that do not provide an implicit interest rate, an incremental borrowing rate (“IBR”) is applied in determining the present value of future payments. The Company’s IBR is selected based upon information available at the lease commencement date. ROU assets are recorded as “Other assets” and lease liabilities are recorded as “Other current liabilities” and “Other liabilities” on the Consolidated Balance Sheets. Operating lease expense is recognized on a straight-line basis over the lease term and is included in either “Cost of goods sold” or “Selling, general and administrative expenses” in the Consolidated Statements of Operations. Costs associated with finance leases and lease income do not have a material impact on the Company’s financial statements.
Revenue	Revenue — The Company recognizes revenue when performance obligations have been satisfied by transferring control of the goods to customers. Control is generally transferred upon delivery of the goods to the customer. At the time of delivery, the customer is invoiced using previously agreed-upon credit terms. Shipping and/or handling costs that occur before the customer obtains control of the goods are deemed fulfillment activities and are accounted for as fulfillment costs. The Company’s contracts with customers generally contain one performance obligation. Many of the Company’s contracts with customers include some form of variable consideration. The most common forms of variable consideration are trade promotions, rebates and discounts. Variable consideration is treated as a reduction of revenue at the time product revenue is recognized. Depending on the nature of the variable consideration, the Company uses either the “expected value” or the “most likely amount” method to determine variable consideration. The Company does not believe that there will be significant changes to its estimates of variable consideration when any uncertainties are resolved with customers.
Cost of Good Sold	Cost of Goods Sold —
Advertising	Advertising —
Stock-Based Compensation	Stock-based Compensation — The Company recognizes the cost of employee services received in exchange for awards of equity instruments based on the grant date fair value of the equity or liability award. For liability awards, the fair market value is remeasured at each quarterly reporting period. The cost for equity and liability awards is recognized ratably over the period during which an employee is required to provide service in exchange for the award — the requisite service period (usually the vesting period). Any forfeitures of stock-based awards are recorded as they occur. See Note 19 for disclosures related to stock-based compensation.
Income Tax (Benefit) Expense	Income Taxes — Income tax expense (benefit) is estimated based on income taxes in each jurisdiction and includes the effects of both current tax exposures and the temporary differences resulting from differing treatment of items for tax and financial reporting purposes. These temporary differences result in deferred tax assets and liabilities. A valuation allowance is established against the related deferred tax assets to the extent that it is more likely than not that the future benefits will not be realized. Reserves are recorded for estimated exposures associated with the Company’s tax filing positions, which are subject to periodic audits by governmental taxing authorities. Interest incurred due to an underpayment of income taxes is classified as income tax expense. The Company considers the undistributed earnings of its foreign subsidiaries to be permanently invested, so no United States (“U.S.”) taxes have been provided in relation to the Company’s investment in its foreign subsidiaries. See Note 9 for disclosures related to income taxes.
Earnings Per Share	Earnings (Loss) per Share — The Company presents basic and diluted earnings (loss) per share for both continuing and discontinued operations. Basic earnings (loss) per share is based on the average number of shares of common stock outstanding during the year. Diluted earnings (loss) per share is based on the average number of shares used for the basic earnings (loss) per share calculation, adjusted for the dilutive effect of stock options, stock appreciation rights and restricted stock units using the “treasury stock” method and convertible senior notes using the “if-converted” method. Remeasurements to the redemption value of the redeemable noncontrolling interest (“NCI”) (as discussed in Note 5) are recognized as a deemed dividend. The Company has made an election to treat the portion of the deemed dividend that exceeds fair value as an adjustment to income available to common shareholders for basic and diluted earnings (loss) from continuing operations per share. In addition, dilutive net earnings from continuing operations was adjusted for interest expense, net of tax, related to the Company’s convertible senior notes, and dilutive net earnings from discontinued operations was adjusted for the Company’s share of Old BellRing’s consolidated net earnings prior to the BellRing Spin-off, to the extent it was dilutive. Net earnings (loss) from continuing operations was utilized as the “control number” to determine whether potential shares of common stock were dilutive or anti-dilutive.

Debt (Policies)

Debt (Policies)	12 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Debt, Policy	The initial conversion rate of the 2.50% convertible senior notes is 9.4248 shares of the Company’s common stock per one thousand principal amount of notes, which represents an initial conversion price of approximately $106.10 per share of common stock. The conversion rate, and thus the conversion price, may be adjusted under certain circumstances as described in the indenture governing the 2.50% convertible senior notes (the “Indenture”). The Company may settle conversions by paying or delivering, as applicable, cash, shares of its common stock or a combination of cash and shares of its common stock, at the Company’s election. If a “make-whole fundamental change” (as defined in the Indenture) occurs, then the Company will in certain circumstances increase the conversion rate for a specified period of time. The 2.50% convertible senior notes may be converted at the holder’s option up to the second scheduled trading day immediately before the maturity date of August 15, 2027 under the following circumstances: • during any calendar quarter (and only during such calendar quarter) commencing after the calendar quarter ended September 30, 2022, if the last reported sale price per share of the Company’s common stock exceeds 130% of the conversion price for each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter; • during the five consecutive business days immediately after any 10 consecutive trading day period (such 10 consecutive trading day period, the “Measurement Period”) in which the trading price per one thousand principal amount of notes for each trading day of the Measurement Period was less than 98% of the product of the last reported sale price per share of the Company’s common stock on such trading day and the conversion rate on such trading day; • upon the occurrence of certain corporate events or distributions on the Company’s common stock described in the Indenture; • if the Company calls the notes for redemption; and • at any time from, and including, May 15, 2027 until the close of business on the second scheduled trading day immediately before the August 15, 2027 maturity date. If a “fundamental change” (as defined in the Indenture) occurs, then, except as described in the Indenture, holders of the 2.50% convertible senior notes may require the Company to repurchase their notes at a cash repurchase price equal to the principal amount of the 2.50% convertible senior notes to be repurchased, plus accrued and unpaid interest, if any, to, but excluding, the “fundamental change repurchase date” (as defined in the Indenture). The 2.50% convertible senior notes may be redeemed, in whole or in part (subject to the partial redemption limitation described in the Indenture), at the Company’s option at any time, and from time to time, on or after August 20, 2025 and on or before the 35th scheduled trading day immediately before August 15, 2027, at a cash redemption price equal to the principal amount of the notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date, only if the last reported sale price per share of the Company’s common stock exceeds 130% of the conversion price on (i) each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date the Company sends the related redemption notice, and (ii) the trading day immediately before the date the Company sends such notice.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Property	September 30, 2022 2021 Land and land improvements $ 92.2 $ 106.2 Buildings and leasehold improvements 932.7 939.4 Machinery and equipment 1,951.1 1,949.6 Software 110.6 111.4 Construction in progress 182.7 111.3 3,269.3 3,217.9 Accumulated depreciation (1,517.4) (1,387.4) $ 1,751.9 $ 1,830.5
Other intangible assets	September 30, 2022 September 30, 2021 Carrying Accum. Net Carrying Accum. Net Subject to amortization: Customer relationships $ 2,129.7 $ (816.4) $ 1,313.3 $ 2,163.1 $ (716.4) $ 1,446.7 Trademarks and brands 647.7 (260.4) 387.3 647.9 (228.5) 419.4 2,777.4 (1,076.8) 1,700.6 2,811.0 (944.9) 1,866.1 Not subject to amortization: Trademarks and brands 1,011.6 — 1,011.6 1,058.3 — 1,058.3 $ 3,789.0 $ (1,076.8) $ 2,712.2 $ 3,869.3 $ (944.9) $ 2,924.4

Discontinued Operations and D_2

Discontinued Operations and Disposal Groups (Tables)	12 Months Ended
	Sep. 30, 2022
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations, Net Assets	The following is a summary of BellRing’s assets and liabilities as of March 10, 2022. March 10, 2022 Assets Cash and cash equivalents (a) $ 50.6 Receivables, net 120.0 Inventories 146.1 Prepaid expenses and other current assets 17.0 Property, net 8.7 Goodwill 65.9 Other intangible assets, net 214.4 Other assets 10.3 Total Assets 633.0 Liabilities Current portion of long-term debt — Accounts payable 69.5 Other current liabilities 40.5 Long-term debt 938.8 Deferred income taxes (b) 6.3 Other liabilities 9.5 Total Liabilities 1,064.6 BellRing Net Assets $ (431.6)
Net Earnings from Discontinued Operations	The following table presents the components of net earnings from discontinued operations. The year ended September 30, 2022 represents the period ending March 10, 2022, the completion date of the BellRing Spin-off. Year Ended September 30, 2022 2021 2020 Net Sales $ 541.9 $ 1,246.0 $ 987.7 Cost of goods sold 390.3 859.8 649.7 Gross Profit 151.6 386.2 338.0 Selling, general and administrative expenses 68.5 167.1 151.8 Amortization of intangible assets 8.7 51.2 22.2 Other operating income, net — (0.1) — Operating Profit 74.4 168.0 164.0 Interest expense, net 13.1 43.2 54.7 Loss on extinguishment and refinancing of debt, net 17.6 1.6 — Earnings from Discontinued Operations before Income Taxes 43.7 123.2 109.3 Income tax expense 10.3 28.4 24.8 Net Earnings from Discontinued Operations, Including Noncontrolling Interest 33.4 94.8 84.5 Less: Net earnings attributable to noncontrolling interest from discontinued operations 11.8 33.0 27.2 Net Earnings from Discontinued Operations, net of tax and noncontrolling interest $ 21.6 $ 61.8 $ 57.3
Discontinued Operations, Carrying Value of Assets	The following table presents the carrying amounts of major classes of assets and liabilities that were included in discontinued operations at September 30, 2021. There were no assets or liabilities classified as discontinued operations at September 30, 2022. September 30, 2021 Cash and cash equivalents $ 152.6 Receivables, net 101.5 Inventories 117.9 Prepaid expenses and other current assets 13.7 Current assets of discontinued operations $ 385.7 Property, net $ 8.9 Goodwill 65.9 Other intangible assets, net 223.1 Other assets 10.5 Other assets of discontinued operations $ 308.4 Current portion of long-term debt $ 116.3 Accounts payable 89.5 Other current liabilities 43.1 Current liabilities of discontinued operations $ 248.9 Long-term debt $ 481.2 Deferred income taxes 134.8 Other liabilities 11.7 Other liabilities of discontinued operations $ 627.7

Noncontrolling Interests, Equ_2

Noncontrolling Interests, Equity Interests and Related Party Transactions (Tables)	12 Months Ended
	Sep. 30, 2022
Schedule of Equity Method Investments [Line Items]
Effects of changes in ownership of PHPC on Post equity	Year Ended September 30, 2022 2021 PHPC IPO offering costs $ — $ (16.9) Initial valuation of PHPC Warrants — (16.9) Net earnings attributable to redeemable NCI 6.7 5.8 Redemption value adjustment (1.6) — PHPC deemed dividend $ 5.1 $ (28.0)
Redeemable Noncontrolling Interest	As Of and For the Year Ended September 30, 2022 2021 Balance, beginning of year $ 305.0 $ — Impact of PHPC IPO (a) — 271.2 Net earnings attributable to redeemable NCI 6.7 5.8 PHPC deemed dividend (5.1) 28.0 Balance, end of year $ 306.6 $ 305.0 (a) For the year ended September 30, 2021, the impact of the PHPC IPO includes the value of PHPC Units owned by public stockholders of $305.0 less offering costs of $16.9 and the initial valuation of PHPC Warrants of $16.9.
Equity Method Loss Attributable to 8th Avenue	Year Ended September 30, 2021 2020 Net loss attributable to 8th Avenue common shareholders $ (60.6) $ (38.9) 60.5 % 60.5 % Equity method loss attributable to Post $ (36.7) $ (23.5) Less: Amortization of basis difference, net of tax (a) 6.8 6.9 Equity method loss, net of tax $ (43.5) $ (30.4) (a) The Company adjusted the historical basis of 8th Avenue’s assets and liabilities to fair value and recognized a basis difference of $70.3 upon the initial recording of its equity method investment in 8th Avenue. The basis difference related to property, plant and equipment and other intangible assets was initially amortized over the weighted-average useful lives of the assets. During the year ended September 30, 2022, the carrying value of the Company’s investment in 8th Avenue was reduced to zero, resulting in the termination of basis difference amortization in accordance with ASC Topic 323. At September 30, 2021, the remaining basis difference to be amortized was $47.8
8th Avenue Summarized Financial Information	Year Ended September 30, 2022 2021 2020 Net sales $ 1,089.0 $ 900.8 $ 924.2 Gross profit $ 159.9 $ 132.3 $ 160.0 Net loss $ (210.9) $ (24.3) $ (6.4) Less: Preferred stock dividend 40.4 36.3 32.5 Net loss attributable to 8th Avenue common shareholders $ (251.3) $ (60.6) $ (38.9) September 30, 2022 2021 Current assets $ 337.0 $ 282.8 Other assets 746.6 903.0 Total Assets $ 1,083.6 $ 1,185.8 Current portion of long-term debt $ 6.5 $ 6.5 Accounts payable and other current liabilities 166.3 131.7 Long-term debt 862.4 780.0 Other liabilities 54.1 63.0 Total Liabilities 1,089.3 981.2 Preferred stock 138.3 97.9 Other shareholders’ (deficit) equity (144.0) 106.7 Shareholders’ (Deficit) Equity (5.7) 204.6 Total Liabilities and Shareholders’ Equity $ 1,083.6 $ 1,185.8

Business Combinations (Tables)

Business Combinations (Tables)	12 Months Ended
	Sep. 30, 2022
Business Acquisition
Pro Forma Information	Year Ended September 30, 2021 2020 Pro forma net sales $ 5,184.3 $ 5,182.0 Pro forma net earnings (loss) from continuing operations available to common shareholders $ 96.9 $ (42.2) Pro forma basic earnings (loss) from continuing operations per common share $ 1.51 $ (0.61) Pro forma diluted earnings (loss) from continuing operations per common share $ 1.48 $ (0.61)

Goodwill (Tables)

Goodwill (Tables)	12 Months Ended
	Sep. 30, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Carrying Amount of Goodwill	Post Consumer Brands Weetabix Foodservice Refrigerated Retail Total Balance, September 30, 2020 Goodwill (gross) $ 2,011.8 $ 889.5 $ 1,335.6 $ 793.6 $ 5,030.5 Accumulated impairment losses (609.1) — — (48.7) (657.8) Goodwill (net) $ 1,402.7 $ 889.5 $ 1,335.6 $ 744.9 $ 4,372.7 Goodwill acquired 55.1 — 19.4 14.3 88.8 Currency translation adjustment 0.2 39.9 — — 40.1 Balance, September 30, 2021 Goodwill (gross) $ 2,067.1 $ 929.4 $ 1,355.0 $ 807.9 $ 5,159.4 Accumulated impairment losses (609.1) — — (48.7) (657.8) Goodwill (net) $ 1,458.0 $ 929.4 $ 1,355.0 $ 759.2 $ 4,501.6 Goodwill acquired (a) — 13.9 0.3 — 14.2 Sale of business (b) — — — (4.2) (4.2) Currency translation adjustment (0.3) (161.7) — — (162.0) Balance, September 30, 2022 Goodwill (gross) $ 2,066.8 $ 781.6 $ 1,355.3 $ 803.7 $ 5,007.4 Accumulated impairment losses (609.1) — — (48.7) (657.8) Goodwill (net) $ 1,457.7 $ 781.6 $ 1,355.3 $ 755.0 $ 4,349.6 (a) In April 2022, the Company recorded $13.9 of goodwill related to its acquisition of Lacka Foods, and in January 2022, the Company recorded a final measurement period adjustment of $0.3 related to the Almark acquisition. For additional information on the Company’s acquisitions, see Note 6. (b) In December 2021, the Company completed the WEF Transaction. For additional information on the WEF Transaction, see Note 7.

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Components of Earnings (Loss) before Income Taxes and Equity Method Loss	Year Ended September 30, 2022 2021 2020 Domestic $ 799.9 $ 105.9 $ (146.5) Foreign 95.4 108.1 100.6 Earnings (Loss) before Income Taxes and Equity Method Loss $ 895.3 $ 214.0 $ (45.9) Income tax expense (benefit) $ 85.7 $ 58.2 $ (21.3) Effective income tax rate 9.6 % 27.2 % (46.4) %
Reconciliation of expense (benefit) for Income Taxes	Year Ended September 30, 2022 2021 2020 Current: Federal $ 71.1 $ (20.3) $ 9.2 State 11.1 (0.2) 4.6 Foreign 13.2 10.5 9.0 95.4 (10.0) 22.8 Deferred: Federal (9.7) 22.6 (45.9) State — 3.4 (14.6) Foreign — 42.2 16.4 (9.7) 68.2 (44.1) Income tax expense (benefit) $ 85.7 $ 58.2 $ (21.3)
Reconciliation of Income Tax expense (benefit)	Year Ended September 30, 2022 2021 2020 Computed tax (21%) $ 188.0 $ 44.9 $ (9.6) Enacted tax law and changes in deferred tax rates 0.9 40.0 10.2 Gain on investment in BellRing (a) (91.8) — — Non-deductible compensation 5.9 5.4 4.5 State income tax, net of effect on federal tax 10.3 1.7 (7.8) Valuation allowances 1.4 2.9 6.1 Net losses and basis difference attributable to equity method investment (14.1) (9.2) (6.5) Income tax credits (1.9) (1.5) (2.6) Rate differential on foreign income (10.2) (11.0) (10.7) Excess tax benefits for share-based payments (3.6) (6.1) (1.3) Gain on bargain purchase — (2.4) (2.5) Enhanced deduction for food donations (1.0) (0.8) (1.3) Return-to-provision and changes in prior year accruals (0.5) (2.8) (1.4) Other, net (none in excess of 5% of statutory tax) 2.3 (2.9) 1.6 Income tax expense (benefit) $ 85.7 $ 58.2 $ (21.3) (a) No deferred income taxes have been recorded with respect to the non-cash mark-to-market adjustment on the Company’s Investment in BellRing during the year ended September 30, 2022, as the Company expects to fully divest, and has already partially divested through the Debt-for-Equity Exchange, its remaining Investment in BellRing within 12 months of the BellRing Spin-off in a manner intended to qualify as tax-free for U.S. federal income tax purposes. See Note 4 for additional information on the BellRing Spin-off.
Deferred tax assets (liabilities)	September 30, 2022 September 30, 2021 Assets Liabilities Net Assets Liabilities Net Derivatives and mark-to-market adjustments $ 34.9 $ — $ 34.9 $ 100.0 $ — $ 100.0 Disallowed interest carryforwards 55.4 — 55.4 34.2 — 34.2 Lease liabilities 35.8 — 35.8 31.9 — 31.9 Net operating loss and credit carryforwards 24.1 — 24.1 29.1 — 29.1 Stock-based and deferred compensation 19.9 — 19.9 17.5 — 17.5 Accrued liabilities 7.0 — 7.0 9.4 — 9.4 Accrued vacation, incentive and severance 6.2 — 6.2 8.2 — 8.2 Inventory 8.8 — 8.8 4.1 — 4.1 Intangible assets — (611.4) (611.4) — (643.5) (643.5) Property — (197.6) (197.6) — (218.7) (218.7) ROU assets — (32.9) (32.9) — (30.0) (30.0) Pension and other postretirement benefits (11.4) (11.4) — (21.7) (21.7) Basis difference attributable to equity method investment 4.6 — 4.6 — (11.8) (11.8) Other items 5.5 (1.8) 3.7 5.6 (1.8) 3.8 Total gross deferred income taxes 202.2 (855.1) (652.9) 240.0 (927.5) (687.5) Valuation allowance (35.5) — (35.5) (41.6) — (41.6) Total deferred taxes $ 166.7 $ (855.1) $ (688.4) $ 198.4 $ (927.5) $ (729.1)
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits	September 30, 2022 2021 2020 Balance, beginning of year $ 12.5 $ 8.3 $ 8.6 Additions for tax positions taken in current year and acquisitions 0.1 0.3 0.2 Additions for tax positions taken in prior years — 5.2 — Settlements with tax authorities/statute expirations (0.9) (1.3) (0.5) Balance, end of year $ 11.7 $ 12.5 $ 8.3

Earnings per Share (Tables)

Earnings per Share (Tables)	12 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	Year ended September 30, 2022 2021 2020 Net Earnings (Loss) from Continuing Operations Net earnings (loss) from continuing operations $ 735.0 $ 104.9 $ (56.5) Impact of redeemable NCI — (11.0) — Net earnings (loss) from continuing operations for basic earnings (loss) per share $ 735.0 $ 93.9 $ (56.5) Impact of interest expense, net of tax, related to convertible senior notes 1.5 — — Net earnings (loss) from continuing operations for diluted earnings (loss) per share $ 736.5 $ 93.9 $ (56.5) Net Earnings from Discontinued Operations Net earnings from discontinued operations for basic earnings per share $ 21.6 $ 61.8 $ 57.3 Dilutive impact of Old BellRing net earnings from discontinued operations — (0.1) — Net earnings from discontinued operations for diluted earnings per share $ 21.6 $ 61.7 $ 57.3 Net Earnings Net earnings for basic earnings per share $ 756.6 $ 155.7 $ 0.8 Net earnings for diluted earnings per share $ 758.1 $ 155.6 $ 0.8 shares in millions Weighted-average shares for basic earnings per share 60.9 64.2 68.9 Effect of dilutive securities: Stock options 0.3 0.6 — Stock appreciation rights 0.1 0.1 — Restricted stock units 0.5 0.3 — Market-based performance restricted stock units 0.1 0.1 — Earnings-based performance restricted stock units 0.1 — — Shares issuable upon conversion of convertible senior notes 0.7 — — Total dilutive securities 1.8 1.1 — Weighted-average shares for diluted earnings per share 62.7 65.3 68.9 Earnings (Loss) from Continuing Operations per Common Share: Basic $ 12.07 $ 1.46 $ (0.82) Diluted $ 11.75 $ 1.44 $ (0.82) Earnings from Discontinued Operations per Common Share: Basic $ 0.35 $ 0.96 $ 0.83 Diluted $ 0.34 $ 0.94 $ 0.83 Earnings per Common Share: Basic $ 12.42 $ 2.42 $ 0.01 Diluted $ 12.09 $ 2.38 $ 0.01
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	Year ended September 30, 2022 2021 2020 Stock options — — 1.6 Stock appreciation rights — — 0.1 Restricted stock units 0.3 — 0.5 Market-based performance restricted stock units 0.1 — 0.2

Supplemental Operations State_2

Supplemental Operations Statement and Cash Flow Information (Tables)	12 Months Ended
	Sep. 30, 2022
Supplemental Operations Statement and Cash Flow Information [Abstract]
Supplemental Operations Statement and Cash Flow Information	Year Ended September 30, 2022 2021 2020 Advertising expenses $ 93.2 $ 112.3 $ 113.1 Research and development expenses 18.9 21.9 19.1 Interest income (4.4) (0.6) (6.2) Interest paid 320.0 348.2 300.0 Income taxes paid 45.8 45.6 44.4 Accrued additions to property 36.4 38.3 29.8

Supplemental Balance Sheet In_2

Supplemental Balance Sheet Information (Tables)	12 Months Ended
	Sep. 30, 2022
Supplemental Balance Sheet Information [Abstract]
Supplemental Balance Sheet Information	September 30, 2022 2021 Receivables, net Trade $ 499.4 $ 374.8 Income tax receivable 17.4 57.2 Related party 4.4 4.6 Other 25.3 18.0 546.5 454.6 Allowance for credit losses (2.3) (2.2) $ 544.2 $ 452.4 Inventories Raw materials and supplies $ 130.9 $ 99.6 Work in process 21.1 19.2 Finished products 361.9 318.7 Flocks 35.2 39.1 $ 549.1 $ 476.6 Other Assets Pension asset $ 93.9 $ 153.4 Operating ROU assets 122.9 115.5 Other investments 26.9 22.9 Derivative assets 3.0 29.1 Other 20.1 27.1 $ 266.8 $ 348.0 Accounts Payable Trade $ 362.1 $ 369.1 Book cash overdrafts 53.3 1.5 Related party 26.1 1.2 Other 11.2 12.4 $ 452.7 $ 384.2 Other Current Liabilities Advertising and promotion $ 47.2 $ 40.2 Accrued interest 69.5 68.1 Accrued compensation 63.4 41.7 Hedging liabilities 25.9 127.7 Operating lease liabilities 25.5 23.5 Accrued freight 25.1 24.0 Other accrued taxes 19.1 21.6 Other 94.3 68.2 $ 370.0 $ 415.0 Other Liabilities Pension and other postretirement benefit obligations $ 45.6 $ 64.2 Derivative liabilities 49.1 256.0 Accrued compensation 33.1 36.1 Operating lease liabilities 113.7 105.2 Other 25.4 46.4 $ 266.9 $ 507.9

Derivative Financial Instrume_2

Derivative Financial Instruments and Hedging (Tables)	12 Months Ended
	Sep. 30, 2022
Derivative [Line Items]
Schedule of Notional Amounts of Outstanding Derivative Positions	September 30, September 30, Commodity contracts $ 145.0 $ 56.4 Energy contracts 23.7 45.9 Foreign exchange contracts - Forward contracts 3.2 — Interest rate swap 200.0 200.0 Interest rate swaps - Rate-lock swaps 849.3 1,549.3 Interest rate swaps - Options 332.6 — PHPC Warrants 16.9 16.9
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	Balance Sheet Location September 30, September 30, Asset Derivatives: Commodity contracts Prepaid expenses and other current assets $ 12.9 $ 16.3 Energy contracts Prepaid expenses and other current assets 13.6 20.1 Interest rate swaps Prepaid expenses and other current assets 3.4 — Commodity contracts Other assets 0.5 2.9 Energy contracts Other assets — 2.0 Interest rate swaps Other assets 2.5 24.2 $ 32.9 $ 65.5 Liability Derivatives: Commodity contracts Other current liabilities $ 1.5 $ 2.8 Energy contracts Other current liabilities 1.8 — Interest rate swaps Other current liabilities 22.5 124.9 Foreign exchange contracts Other current liabilities 0.1 — Interest rate swaps Other liabilities 48.1 246.8 PHPC Warrants Other liabilities 1.0 9.2 $ 75.0 $ 383.7
Schedule of Derivative Instruments, Loss (Gain) in Statement of Financial Performance	Derivatives Not Designated as Hedging Instruments Statement of Operations Location (Gain) Loss Recognized in Statement of Operations 2022 2021 2020 Commodity contracts Cost of goods sold $ (32.2) $ (11.3) $ 3.8 Energy contracts Cost of goods sold (28.5) (43.1) 21.6 Foreign exchange contracts Selling, general and administrative expenses 0.1 0.1 (0.1) Interest rate swaps (Income) expense on swaps, net (268.0) (122.8) 187.1 PHPC Warrants Other income, net (8.2) (7.7) — The following table presents the effects of the Company’s derivative instruments on the Company’s Consolidated Statement of Comprehensive Income for the year ended September 30, 2020. The effects of the Company’s derivative instruments for the years ended September 30, 2022 and 2021 included in the Company’s Consolidated Statements of Comprehensive Income related to the Company’s discontinued operations and therefore were not included in the table below. Derivatives Designated as Hedging Instruments Gain Recognized in OCI Loss Reclassified from Accumulated OCI into Earnings (a) Statement of Operations Location Interest rate swaps $ (0.6) $ 7.2 Interest expense, net Cross-currency swaps (32.2) — (Income) expense on swaps, net (a) This amount includes the amortization of previously unrealized losses on interest rate swaps that were de-designated as hedging instruments in the first quarter of fiscal 2020.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Assets and liabilities measured at fair value on a recurring basis	September 30, 2022 September 30, 2021 Total Level 1 Level 2 Total Level 1 Level 2 Assets: Deferred compensation investment $ 12.0 $ 12.0 $ — $ 15.5 $ 15.5 $ — Derivative assets 32.9 — 32.9 65.5 — 65.5 Equity securities 32.1 32.1 — 28.9 28.9 — Investment in BellRing 94.8 94.8 — — — — $ 171.8 $ 138.9 $ 32.9 $ 109.9 $ 44.4 $ 65.5 Liabilities: Deferred compensation liabilities $ 33.7 $ — $ 33.7 $ 36.0 $ — $ 36.0 Derivative liabilities 75.0 1.0 74.0 383.7 9.2 374.5 $ 108.7 $ 1.0 $ 107.7 $ 419.7 $ 9.2 $ 410.5
Fair Value Measurements, Nonrecurring	Balance, September 30, 2020 $ 7.3 Proceeds from the sale of assets held for sale (7.9) Currency translation adjustment 0.1 Net gain related to assets held for sale 0.5 Balance, September 30, 2021 $ — Transfers of assets into held for sale 1.0 Net gain related to assets held for sale 9.4 Proceeds from the sale of assets held for sale (10.3) Balance, September 30, 2022 $ 0.1

Leases (Tables)

Leases (Tables)	12 Months Ended
	Sep. 30, 2022
Leases [Abstract]
Summary of ROU Assets and Lease Liabilities	September 30, 2022 September 30, 2021 ROU assets: Other assets $ 122.9 $ 115.5 Lease liabilities: Other current liabilities $ 25.5 $ 23.5 Other liabilities 113.7 105.2 Total lease liabilities $ 139.2 $ 128.7
Maturities of Lease Liabilities, under ASC Topic 842	September 30, 2022 Fiscal 2023 $ 32.1 Fiscal 2024 26.3 Fiscal 2025 20.4 Fiscal 2026 18.9 Fiscal 2027 14.5 Thereafter 64.3 Total future minimum payments $ 176.5 Less: Implied interest 37.3 Total lease liabilities $ 139.2
Lease, Cost	Year Ended September 30, 2022 2021 2020 Operating lease expense $45.5 $40.1 $38.0 Variable lease expense 5.2 4.8 4.5 Short-term lease expense 9.4 7.5 7.4 Weighted-average remaining lease term 9 years 9 years 7 years Weighted-average IBR 5.26% 4.70% 4.46%

Long Term Debt (Tables)

Long Term Debt (Tables)	12 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	September 30, 2022 2021 2.50% convertible senior notes maturing August 2027 $ 575.0 $ — 4.50% senior notes maturing September 2031 1,270.5 1,800.0 4.625% senior notes maturing April 2030 1,482.2 1,650.0 5.50% senior notes maturing December 2029 1,235.0 750.0 5.625% senior notes maturing January 2028 940.9 940.9 5.75% senior notes maturing March 2027 459.3 1,299.3 Municipal bond 6.4 7.5 $ 5,969.3 $ 6,447.7 Less: Current portion of long-term debt 1.1 1.1 Debt issuance costs, net 50.1 47.2 Plus: Unamortized premium, net 38.5 42.2 Total long-term debt $ 5,956.6 $ 6,441.6
Schedule of Maturities of Long-term Debt	September 30, 2022 Fiscal 2023 $ 1.1 Fiscal 2024 1.1 Fiscal 2025 1.2 Fiscal 2026 1.2 Fiscal 2027 (a) 1,035.6 (a) Includes principal payments of $575.0 related to the Company’s 2.50% convertible senior notes.
Repayments of Long-Term Debt	The following table presents the Company’s cash repayments of debt, net of discounts included in the Consolidated Statements of Cash Flows and associated gain or loss included in “(Gain) loss on extinguishment of debt, net” in the Consolidated Statements of Operations. Cash repayments of debt (Gain) Loss on Extinguishment of Debt, net Year Ended Issuance Principal Amount Repaid Debt Discounts (Received) / Premiums Paid Write-off of Debt Issuance Costs / Write-off of Unamortized Premium 4.50% senior notes $ 529.5 $ (74.7) $ 6.0 $ — 4.625% senior notes 167.8 (21.9) 1.1 (1.8) 5.50% senior notes maturing in 2029 15.0 (1.2) 0.1 (0.2) 5.75% senior notes 840.0 24.1 5.0 (13.3) Second Incremental Term Loan 107.7 — — — Municipal bond 1.1 — — — 2022 Total $ 1,661.1 $ (73.7) $ 12.2 $ (15.3) 5.00% senior notes $ 1,697.3 $ 74.3 $ 18.9 $ — Municipal bond 1.0 — — — 2021 Total $ 1,698.3 $ 74.3 $ 18.9 $ — Term Loan $ 1,309.5 $ — $ 9.1 $ — 5.50% senior notes maturing in 2025 1,000.0 41.3 8.7 — Revolving Credit Facility 500.0 — — — 8.00% senior notes 122.2 8.5 0.7 — Municipal bond 1.1 — — — Credit Agreement — — 0.8 — 2020 Total $ 2,932.8 $ 49.8 $ 19.3 $ — The following table presents the Company’s non-cash repayments of debt, which are not included in the Consolidated Statements of Cash Flows, and the associated gain or loss included in “(Gain) loss on extinguishment of debt, net” in the Consolidated Statements of Operations. There were no non-cash repayments of debt for the year ended September 30, 2021. Non-cash repayments of debt (Gain) Loss on Extinguishment of Debt, net Year Ended Issuance Principal Amount Repaid Debt Discounts (Received) / Premiums Paid Write-off of Debt Issuance Costs Write-off of Unamortized Premium First Incremental Term Loan $ 840.0 $ — $ 3.5 $ — Second Incremental Term Loan 342.3 — 0.7 — 2022 Total $ 1,182.3 $ — $ 4.2 $ — 2020 Bridge Loan $ 1,225.0 $ — $ 3.8 $ — 2020 Total $ 1,225.0 $ — $ 3.8 $ —

Pension and Other Postretirem_2

Pension and Other Postretirement Benefits (Tables)	12 Months Ended
	Sep. 30, 2022
Defined Benefit Plan Disclosure
Schedule of change in projected benefit obligation, change in fair value of plan assets, and net funded status	The following table provides a reconciliation of the changes in the pension plans’ benefit obligations and fair value of assets over the two year period ended September 30, 2022 and a statement of the funded status and amounts recognized on the Consolidated Balance Sheets as of September 30, 2022 and 2021. North America Other International Year Ended Year Ended 2022 2021 2022 2021 Change in benefit obligation Benefit obligation at beginning of year $ 133.3 $ 131.1 $ 821.3 $ 834.4 Service cost 4.3 3.9 — — Interest cost 3.5 3.2 15.7 15.2 Plan participants’ contributions 0.4 0.4 — — Prior service cost (a) — 0.5 — — Actuarial gain (38.9) (1.4) (251.6) (32.7) Business combinations — 0.5 — — Benefits paid (5.9) (5.8) (28.4) (34.7) Currency translation (1.2) 0.9 (135.9) 39.1 Benefit obligation at end of year $ 95.5 $ 133.3 $ 421.1 $ 821.3 Change in fair value of plan assets Fair value of plan assets at beginning of year $ 136.6 $ 121.5 $ 970.9 $ 993.2 Actual return on plan assets (27.1) 19.5 (273.0) (34.1) Employer contributions 0.4 0.2 — — Plan participants’ contributions 0.4 0.4 — — Benefits paid (5.9) (5.8) (28.4) (34.7) Currency translation (1.5) 0.8 (162.1) 46.7 Other — — (0.1) (0.2) Fair value of plan assets at end of year 102.9 136.6 507.3 970.9 Funded status $ 7.4 $ 3.3 $ 86.2 $ 149.6 Amounts recognized in assets or liabilities Other assets $ 7.7 $ 3.8 $ 86.2 $ 149.6 Other liabilities (0.3) (0.5) — — Net amount recognized $ 7.4 $ 3.3 $ 86.2 $ 149.6 Amounts recognized in accumulated OCI Net actuarial loss (gain) $ 5.0 $ 11.3 $ 40.2 $ (6.0) Prior service cost 0.6 0.7 10.7 11.1 Total $ 5.6 $ 12.0 $ 50.9 $ 5.1 Weighted-average assumptions used to determine benefit obligation Discount rate — U.S. plans 5.65 % 3.05 % n/a n/a Discount rate — Canadian plans 5.12 % 3.32 % n/a n/a Discount rate — Other international plans n/a n/a 5.15 % 2.05 % Rate of compensation increase — U.S. plans 3.00 % 3.00 % n/a n/a Rate of compensation increase — Canadian plans 2.75 % 2.75 % n/a n/a Rate of compensation increase — Other international plans n/a n/a 3.85 % 3.45 % (a) Amounts reported for the year ended September 30, 2021 represent the impact of fiscal 2020 union negotiations that were ratified subsequent to September 30, 2020. The following table provides a reconciliation of the changes in the North American other postretirement benefit obligations over the two year period ended September 30, 2022. Besides the North American plans, the Company does not maintain any other postretirement benefit plans. Year Ended 2022 2021 Change in benefit obligation Benefit obligation at beginning of year $ 66.5 $ 70.7 Service cost 0.5 0.5 Interest cost 1.5 1.5 Actuarial gain (17.4) (4.3) Benefits paid (2.3) (2.4) Currency translation (0.5) 0.5 Benefit obligation at end of year $ 48.3 $ 66.5 Change in fair value of plan assets Employer contributions 2.3 2.4 Benefits paid (2.3) (2.4) Fair value of plan assets at end of year — — Funded status $ (48.3) $ (66.5) Amounts recognized in assets or liabilities Other current liabilities (3.0) (2.8) Other liabilities (45.3) (63.7) Net amount recognized $ (48.3) $ (66.5) Amounts recognized in accumulated OCI Net actuarial loss $ (9.2) $ 8.9 Prior service credit (5.4) (10.0) Total $ (14.6) $ (1.1) Weighted-average assumptions used to determine benefit obligation Discount rate — U.S. plans 5.62 % 2.89 % Discount rate — Canadian plans 5.12 % 3.45 % Rate of compensation increase — Canadian plans 2.75 % 2.75 %
Pension plan's assets measured at fair value on a recurring basis	North America September 30, 2022 September 30, 2021 Total Level 1 Level 2 Total Level 1 Level 2 Equities $ 11.0 $ — $ 11.0 $ 13.8 $ — $ 13.8 Fixed income and bonds 5.0 — 5.0 5.7 — 5.7 Cash and cash equivalents 8.9 8.9 — 3.4 3.4 — Fair value of plan assets in the fair value hierarchy 24.9 8.9 16.0 22.9 3.4 19.5 Equities 45.1 — — 70.1 — — Fixed income and bonds 29.9 — — 41.2 — — Real assets 3.0 — — 2.4 — — Investments measured at net asset value (a) 78.0 — — 113.7 — — Total plan assets $ 102.9 $ 8.9 $ 16.0 $ 136.6 $ 3.4 $ 19.5 Other International September 30, 2022 September 30, 2021 Total Level 1 Level 2 Total Level 1 Level 2 Fixed income and bonds $ 321.3 $ 321.3 $ — $ 649.3 $ 649.3 $ — Liability driven instruments 77.9 77.9 — 206.4 206.4 — Cash and cash equivalents 10.6 10.6 — 17.8 17.8 — Fair value of plan assets in the fair value hierarchy 409.8 409.8 — 873.5 873.5 — Fixed income and bonds 78.5 — — 56.1 — — Liability driven instruments 16.9 — — 29.3 — — Real assets 2.1 — — 9.5 — — Cash and cash equivalents — — — 2.5 — — Investments measured at net asset value (a) 97.5 — — 97.4 — — Total plan assets $ 507.3 $ 409.8 $ — $ 970.9 $ 873.5 $ — (a) In accordance with ASC Topic 820, certain investments were measured at NAV. In cases where the fair value was measured at NAV using the practical expedient provided for in ASC Topic 820, the investments have not been classified in the fair value hierarchy. The fair value amounts presented in these tables are intended to permit reconciliation of the fair value hierarchy to the tables above.
Expected future benefit payments and related federal subsidy receipts	2023 2024 2025 2026 2027 2028 - 2032 Pension benefits $ 24.3 $ 24.8 $ 25.9 $ 27.1 $ 28.2 $ 156.2 Other benefits 3.2 3.4 3.4 3.4 3.5 17.9 Subsidy receipts 0.1 0.1 0.1 0.2 0.2 1.1
Pension Benefits
Defined Benefit Plan Disclosure
Schedule of net benefit costs and assumptions used in calculation	The following tables provide the components of net periodic benefit cost for the pension plans including amounts recognized in OCI. For the years ended September 30, 2022, 2021 and 2020, service cost was reported in “Cost of goods sold” and “Selling, general and administrative expenses” and all other components of net periodic benefit cost were reported in “Other income, net” in the Consolidated Statements of Operations. North America Year Ended September 30, 2022 2021 2020 Components of net periodic benefit cost Service cost $ 4.3 $ 3.9 $ 4.3 Interest cost 3.5 3.2 3.7 Expected return on plan assets (7.0) (6.4) (6.4) Recognized net actuarial loss 1.6 2.4 1.8 Recognized prior service cost 0.1 0.1 0.1 Net periodic benefit cost $ 2.5 $ 3.2 $ 3.5 Weighted-average assumptions used to determine net benefit cost Discount rate — U.S. plans 3.05 % 3.01 % 3.32 % Discount rate — Canadian plans 3.32 % 2.71 % 2.84 % Rate of compensation increase — U.S. plans 3.00 % 3.00 % 3.00 % Rate of compensation increase — Canadian plans 2.75 % 2.75 % 2.75 % Expected return on plan assets — U.S. plans 5.75 % 5.40 % 5.53 % Expected return on plan assets — Canadian plans 5.25 % 5.25 % 5.75 % Changes in plan assets and benefit obligation recognized in total comprehensive income Net (gain) loss $ (4.7) $ (14.5) $ 6.6 Recognized loss (1.6) (2.4) (1.8) Prior service cost (a) — 0.5 — Recognized prior service cost (0.1) (0.1) (0.1) Total recognized in OCI (before tax effects) $ (6.4) $ (16.5) $ 4.7 (a) Amounts reported for the year ended September 30, 2021 represent the impact of fiscal 2020 union negotiations that were ratified subsequent to September 30, 2020. Other International Year Ended September 30, 2022 2021 2020 Components of net periodic benefit cost Interest cost $ 15.7 $ 15.2 $ 14.7 Expected return on plan assets (24.8) (24.9) (24.6) Recognized prior service cost 0.4 0.5 — Net periodic benefit income $ (8.7) $ (9.2) $ (9.9) Weighted-average assumptions used to determine net benefit cost Discount rate 2.05 % 1.73 % 1.84 % Rate of compensation increase 3.45 % 2.65 % 2.55 % Expected return on plan assets 2.73 % 2.38 % 2.53 % Changes in plan assets and benefit obligation recognized in total comprehensive income Net loss $ 46.2 $ 26.4 $ 14.2 Prior service cost (a) — — 11.4 Recognized prior service cost (0.4) (0.5) — Total recognized in OCI (before tax effects) $ 45.8 $ 25.9 $ 25.6 (a) During the year ended September 30, 2020, the Company recognized prior service cost as a result of an amendment to the benefit plan for Weetabix employees in the U.K. participating in the group scheme.
Other Benefits
Defined Benefit Plan Disclosure
Schedule of net benefit costs and assumptions used in calculation	The following table provides the components of net periodic benefit cost for the other postretirement benefit plans including amounts recognized in OCI. For the years ended September 30, 2022, 2021 and 2020, service cost was reported in “Cost of goods sold” and “Selling, general and administrative expenses” and all other components of net periodic benefit cost were reported in “Other income, net” in the Consolidated Statements of Operations. Year Ended September 30, 2022 2021 2020 Components of net periodic benefit cost Service cost $ 0.5 $ 0.5 $ 0.6 Interest cost 1.5 1.5 1.9 Recognized net actuarial loss 0.6 1.1 0.6 Recognized prior service credit (4.6) (4.7) (4.7) Net periodic benefit cost $ (2.0) $ (1.6) $ (1.6) Weighted-average assumptions used to determine net benefit cost Discount rate — U.S. plans 2.89 % 2.79 % 3.20 % Discount rate — Canadian plans 3.45 % 2.78 % 2.86 % Rate of compensation increase — Canadian plans 2.75 % 2.75 % 2.75 % Changes in benefit obligation recognized in total comprehensive income Net (gain) loss $ (17.5) $ (4.3) $ 4.6 Recognized net actuarial loss (0.6) (1.1) (0.6) Recognized prior service credit 4.6 4.7 4.7 Total recognized in OCI (before tax effects) $ (13.5) $ (0.7) $ 8.7

Stock-Based Compensation Plans

Stock-Based Compensation Plans (Tables)	12 Months Ended
	Sep. 30, 2022
Post Stock Settled
Share-based Payment Award [Line Items]
Stock Appreciation Rights, Activity	in millions, except SARs or where otherwise indicated SARs Weighted- Weighted- Aggregate Outstanding at September 30, 2021 95,000 $ 46.59 Granted — Impact of BellRing Spin-off 41,038 33.62 Exercised (54,484) 31.22 Forfeited — Expired — Outstanding at September 30, 2022 81,554 33.42 1.64 $ 4.0 Vested and expected to vest as of September 30, 2022 81,554 33.42 1.64 4.0 Exercisable at September 30, 2022 81,554 33.42 1.64 4.0 (a) The weighted-average exercise price per share for activity subsequent to the BellRing Spin-off, including the outstanding balance as of September 30, 2022, reflects the adjustment to preserve the intrinsic value of the Equity Awards outstanding immediately prior to the BellRing Spin-off. Upon exercise of each SAR, the holder will receive the number of shares of Post common stock equal in value to the difference between the exercise price and the fair market value at the date of exercise, less all applicable taxes. The total intrinsic value of SARs exercised was $3.0, $3.2 and $0.1 during the years ended September 30, 2022, 2021 and 2020, respectively. There were no SARs granted during the years ended September 30, 2022, 2021 or 2020.
Restricted Stock Units, Activity	RSUs Weighted- Nonvested at September 30, 2021 822,112 $ 97.23 Granted 432,538 102.58 Impact of BellRing Spin-off (b) 520,090 n/a Vested (361,026) 91.68 Forfeited (64,908) 81.63 Nonvested at September 30, 2022 1,348,806 68.38
Post Stock Options
Share-based Payment Award [Line Items]
Stock Options, Activity	in millions, except stock options or where otherwise indicated Stock Options Weighted- Weighted- Aggregate Outstanding at September 30, 2021 889,096 $ 65.67 Granted — — Impact of BellRing Spin-off 353,559 48.89 Exercised (231,340) 39.28 Forfeited — — Expired — — Outstanding at September 30, 2022 1,011,315 48.75 4.34 $ 33.5 Vested and expected to vest as of September 30, 2022 1,011,315 48.75 4.34 33.5 Exercisable at September 30, 2022 996,235 48.40 4.30 33.4 (a) The weighted-average exercise price per share for activity subsequent to the BellRing Spin-off, including the outstanding balance as of September 30, 2022, reflects the adjustment to preserve the intrinsic value of the Equity Awards outstanding immediately prior to the BellRing Spin-off.
Stock Options, Valuation Assumptions	Expected term (in years) 6.5 Expected stock price volatility 29.2% Risk-free interest rate 1.8% Expected dividends 0% Fair value (per stock option) $35.32
Post Cash Settled
Share-based Payment Award [Line Items]
Restricted Stock Units, Activity	Cash RSUs Weighted- Nonvested at September 30, 2021 29,400 $ 51.43 Granted — — Impact of BellRing Spin-off 14,193 n/a Vested (14,530) 34.68 Forfeited — — Nonvested at September 30, 2022 29,063 34.68
Earnings-Based Restricted Stock Units
Share-based Payment Award [Line Items]
Performance-Based Restricted Stock Units	Earnings PRSUs Weighted- Nonvested at September 30, 2021 7,526 $ 98.33 Granted 195,533 104.74 Impact of BellRing Spin-off 96,177 n/a Adjustment for performance achievement (b) (12,588) n/a Vested — — Forfeited (14,221) 78.27 Nonvested at September 30, 2022 272,427 70.46 (a) The weighted-average grant date fair value for the activity subsequent to the BellRing Spin-off, including the nonvested balance as of September 30, 2022, reflects the adjustment to preserve the intrinsic value of the Equity Awards outstanding immediately prior to the BellRing Spin-off. (b) Represents the adjustment to previously granted Earnings PRSUs for performance achievement.
Performance RSU, Valuation Assumptions	2022 2021 2020 Expected term (in years) 3.0 3.0 3.0 Expected stock price volatility 27.7% 28.3% 22.2% Risk-free interest rate 0.9% 0.2% 1.6% Fair value (per Market PRSU) $163.63 $152.58 $138.10
Market-based performance shares
Share-based Payment Award [Line Items]
Performance-Based Restricted Stock Units	Market PRSUs Weighted- Nonvested at September 30, 2021 285,335 $ 142.61 Granted 108,922 163.63 Impact of BellRing Spin-off (b) 62,114 n/a Adjustment for performance achievement (c) (19,508) n/a Vested (61,940) 122.34 Forfeited (521) 110.35 Nonvested at September 30, 2022 374,402 106.10 (a) The weighted-average grant date fair value for the activity subsequent to the BellRing Spin-off, including the nonvested balance as of September 30, 2022, reflects the adjustment to preserve the intrinsic value of the Equity Awards outstanding immediately prior to the BellRing Spin-off. (b) The Impact of BellRing Spin-off includes adjustments to preserve the intrinsic value of the Equity Awards outstanding immediately prior to the BellRing Spin-off, offset by the conversion of the Fiscal 2020 Market PRSUs into RSUs. (c) Represents the adjustment to previously granted Market PRSUs for performance achievement.

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
	Sep. 30, 2022
Stockholders' Equity Attributable to Parent [Abstract]
Repurchases of Common Stock	September 30, 2022 2021 2020 Shares repurchased (in millions) 4.9 4.0 6.1 Average price per share including broker’s commissions (a) $ 90.04 $ 98.39 $ 97.67 Total cost including broker’s commissions (b) $ 439.0 $ 393.7 $ 587.8 (a) Average repurchase price per share including broker’s commissions during the year ended September 30, 2022 was $103.81 prior to the BellRing Spin-off and $81.54 subsequent to the BellRing Spin-off. (b) Of the $393.7 total cost recorded during the year ended September 30, 2021, $4.0 was not settled until October 2021 and was included in “Other current liabilities” on the Consolidated Balance Sheet at September 30, 2021.

Segments (Tables)

Segments (Tables)	12 Months Ended
	Sep. 30, 2022
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Year Ended September 30, 2022 2021 2020 Net Sales Post Consumer Brands $ 2,242.7 $ 1,915.3 $ 1,949.1 Weetabix 477.3 477.5 440.4 Foodservice 2,095.0 1,615.6 1,361.8 Refrigerated Retail 1,036.6 974.5 961.2 Eliminations and Corporate (0.4) (2.2) (1.5) Total $ 5,851.2 $ 4,980.7 $ 4,711.0 Segment Profit Post Consumer Brands $ 314.6 $ 316.6 $ 393.5 Weetabix 109.5 115.4 112.3 Foodservice 151.0 61.7 25.6 Refrigerated Retail 57.1 75.9 125.6 Total segment profit 632.2 569.6 657.0 General corporate expenses and other 196.8 52.6 109.0 Interest expense, net 317.8 332.6 333.9 (Gain) loss on extinguishment of debt, net (72.6) 93.2 72.9 (Income) expense on swaps, net (268.0) (122.8) 187.1 Gain on investment in BellRing (437.1) — — Earnings (loss) before income taxes and equity method loss $ 895.3 $ 214.0 $ (45.9) Net sales by product Cereal $ 2,595.0 $ 2,333.3 $ 2,388.7 Nut butters 111.7 58.7 — Eggs and egg products 2,026.1 1,556.1 1,307.8 Side dishes (including potato products) 652.4 575.0 536.6 Cheese and dairy 214.3 223.0 253.2 Sausage 171.2 165.9 168.1 Protein-based products 12.9 — — Other 68.5 70.9 58.1 Eliminations and Corporate (0.9) (2.2) (1.5) Total $ 5,851.2 $ 4,980.7 $ 4,711.0 Additions to property and intangibles Post Consumer Brands $ 91.2 $ 81.2 $ 67.4 Weetabix 26.7 19.6 24.6 Foodservice and Refrigerated Retail 136.1 89.7 139.5 Corporate (a) 20.8 0.4 1.0 Total $ 274.8 $ 190.9 $ 232.5 Depreciation and amortization Post Consumer Brands $ 133.1 $ 122.0 $ 112.4 Weetabix 37.5 39.0 35.9 Foodservice 127.5 126.0 119.6 Refrigerated Retail 78.4 75.5 73.1 Total segment depreciation and amortization 376.5 362.5 341.0 Corporate 3.7 4.0 4.0 Total $ 380.2 $ 366.5 $ 345.0 September 30, 2022 2021 Assets, end of year Post Consumer Brands $ 3,529.1 $ 3,467.8 Weetabix 1,591.3 1,930.4 Foodservice and Refrigerated Retail 5,022.7 5,074.2 Corporate 1,164.9 1,248.2 Total assets of continuing operations 11,308.0 11,720.6 Total assets of discontinued operations — 694.1 Total assets $ 11,308.0 $ 12,414.7 (a) During the year ended September 30, 2022, the Company had non-cash exchanges of fixed assets of $19.5, which were included in the Corporate additions to property and intangibles.

Background (Details)

Background (Details)	Mar. 10, 2022
Post | New BellRing Common Stock
Distribution of ownership in subsidiary, percentage	80.10%

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Weetabix Segment | Operating Segments
Business Acquisition
Receivables Sold	$ 111.7	$ 140.2

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Property (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Property, Plant and Equipment, Net [Abstract]
Depreciation	$ 232.9	$ 222.2	$ 206.7
Property, plant and equipment, gross	3,269.3	3,217.9
Accumulated depreciation	(1,517.4)	(1,387.4)
Property, net	1,751.9	1,830.5
Land
Property, Plant and Equipment, Net [Abstract]
Property, plant and equipment, gross	92.2	106.2
Building and leasehold improvements
Property, Plant and Equipment, Net [Abstract]
Property, plant and equipment, gross	$ 932.7	939.4
Building and leasehold improvements | Minimum
Property, Plant and Equipment, Net [Abstract]
Useful life	1 year
Building and leasehold improvements | Maximum
Property, Plant and Equipment, Net [Abstract]
Useful life	35 years
Machinery and equipment
Property, Plant and Equipment, Net [Abstract]
Property, plant and equipment, gross	$ 1,951.1	1,949.6
Machinery and equipment | Minimum
Property, Plant and Equipment, Net [Abstract]
Useful life	1 year
Machinery and equipment | Maximum
Property, Plant and Equipment, Net [Abstract]
Useful life	29 years
Software
Property, Plant and Equipment, Net [Abstract]
Property, plant and equipment, gross	$ 110.6	111.4
Software | Minimum
Property, Plant and Equipment, Net [Abstract]
Useful life	1 year
Software | Maximum
Property, Plant and Equipment, Net [Abstract]
Useful life	7 years
Construction in Progress
Property, Plant and Equipment, Net [Abstract]
Property, plant and equipment, gross	$ 182.7	$ 111.3

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Other Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Finite-Lived and Indefinite-Lived, Intangible Assets
Amortization of intangible assets	$ 146	$ 143.2	$ 138.1
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
2023	145
2024	143.9
2025	142.6
2026	142.6
2027	142.6
Finite-Lived Intangible Assets [Abstract]
Finite-Lived Intangible Assets, Gross	2,777.4	2,811
Finite-Lived Intangible Assets, Accumulated Amortization	(1,076.8)	(944.9)
Finite-Lived Intangible Assets, Net	1,700.6	1,866.1
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Carrying amount, total	3,789	3,869.3
Other intangible assets, net	2,712.2	2,924.4
Customer Relationships
Finite-Lived Intangible Assets [Abstract]
Finite-Lived Intangible Assets, Gross	2,129.7	2,163.1
Finite-Lived Intangible Assets, Accumulated Amortization	(816.4)	(716.4)
Finite-Lived Intangible Assets, Net	1,313.3	1,446.7
Trademarks
Finite-Lived Intangible Assets [Abstract]
Finite-Lived Intangible Assets, Gross	647.7	647.9
Finite-Lived Intangible Assets, Accumulated Amortization	(260.4)	(228.5)
Finite-Lived Intangible Assets, Net	387.3	419.4
Trademarks
Indefinite-lived Intangible Assets (Excluding Goodwill) [Abstract]
Indefinite-lived Intangible Assets (Excluding Goodwill)	1,011.6	$ 1,058.3
Trademarks | Refrigerated Retail
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Indefinite-Lived Intangible Assets, Written off Related to Sale of Business Unit	1.7
Customer Relationships | Refrigerated Retail
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Indefinite-Lived Intangible Assets, Written off Related to Sale of Business Unit	$ 8.8

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Cost of Products Sold (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Accounting Policies [Abstract]
Cost Of Goods Sold, Storage And Warehouse Costs	$ 204	$ 167.7	$ 160.4

Summary of Significant Accoun_8

Summary of Significant Accounting Policies Advertising (Details) - USD ($) $ in Millions	Sep. 30, 2022	Sep. 30, 2021
Accounting Policies [Abstract]
Prepaid Advertising	$ 1.4	$ 1.1

Discontinued Operations and D_3

Discontinued Operations and Disposal Groups (Details) - USD ($) $ / shares in Units, $ in Millions		5 Months Ended	12 Months Ended
	Mar. 10, 2022	Mar. 10, 2022	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020	Oct. 21, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payment of merger consideration			$ 550.4
Common Stock, Dividends, Per Share, Cash Paid			$ 2.97
Payments for Merger Related Costs		$ 115.5
Investment in BellRing LLC	$ 127.1	127.1
Disposal Group, Including Discontinued Operation, Revenue			$ 541.9	$ 1,246	$ 987.7
Disposal Group, Including Discontinued Operation, Costs of Goods Sold			390.3	859.8	649.7
Disposal Group, Including Discontinued Operation, Gross Profit (Loss)			151.6	386.2	338
Disposal Group, Including Discontinued Operation, General and Administrative Expense			68.5	167.1	151.8
Disposal Group, Including Discontinued Operation, Amortization of intangible assets			8.7	51.2	22.2
Disposal Group, Including Discontinued Operation, Other operating income, net			0	(0.1)	0
Disposal Group, Including Discontinued Operation, Operating Income (Loss)			74.4	168	164
Disposal Group, Including Discontinued Operation, Interest Expense			13.1	43.2	54.7
Disposal Group, Including Discontinued Operation, Loss on extinguishment and refinancing of debt, net			17.6	1.6	0
Earnings from Discontinued Operations before Income Taxes			43.7	123.2	109.3
Disposal Group, Including Discontinued Operation, Income tax expense			10.3	28.4	24.8
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest			33.4	94.8	84.5
Net earnings attributable to noncontrolling interest from discontinued operations			11.8	33	27.2
Net earnings from discontinued operations, net of tax and noncontrolling interest			21.6	61.8	$ 57.3
Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents	50.6	50.6		152.6
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net	120	120		101.5
Disposal Group, Including Discontinued Operation, Inventory, Current	146.1	146.1		117.9
Disposal Group, Including Discontinued Operation, Prepaid and Other Assets, Current	17	17		13.7
Current assets of discontinued operations			0	385.7
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment, Noncurrent	8.7	8.7		8.9
Disposal Group, Including Discontinued Operation, Goodwill, Noncurrent	65.9	65.9		65.9
Disposal Group, Including Discontinued Operation, Intangible Assets, Noncurrent	214.4	214.4		223.1
Disposal Group, Including Discontinued Operation, Other Assets, Noncurrent	10.3	10.3		10.5
Other assets of discontinued operations	633	633	0	308.4
Disposal Group, Including Discontinued Operations, Long-term debt, Curent Maturities	0	0		116.3
Disposal Group, Including Discontinued Operation, Accounts Payable, Current	69.5	69.5		89.5
Disposal Group, Including Discontinued Operation, Other Liabilities, Current	40.5	40.5		43.1
Current liabilities of discontinued operations			0	248.9
Disposal Group, Including Discontinued Operations, Long-term debt, Excluding Current Maturities	938.8	938.8		481.2
Disposal Group, Including Discontinued Operation, Deferred Tax Liabilities	6.3	6.3		134.8
Disposal Group, Including Discontinued Operation, Other Liabilities, Noncurrent	9.5	9.5		11.7
Other liabilities of discontinued operations	1,064.6	1,064.6	0	627.7
Disposal Group, Including Discontinued Operation, Net Assets	(431.6)	(431.6)
Additional Paid-in Capital
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
BellRing Spin-Off	442.5		442.5
Foreign Currency Translation Adjustments
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
BellRing Spin-Off	$ 2.3		$ 2.3
BellRing Brands, Inc. | BellRing Common Stock
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Par value of common stock			$ 0.01
BellRing Brands, Inc. | Common Class B
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Par value of common stock						$ 0.01
BellRing Brands, Inc. | Common Class A
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Par value of common stock						$ 0.01
Common Stock, Shares, Issued						39,400,000
Post
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Separation Costs			$ 29.9	1.6
Old BellRing
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Separation Costs		$ 4.3		$ 0.2
BellRing | 7.00% Senior Notes due 2030 | Senior Notes
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Long-Term Debt, Gross			$ 840
BellRing Brands, LLC | BellRing Brands, Inc.
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners						28.80%
BellRing Brands, LLC | Post
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners						71.20%
Post shareholders | BellRing
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent	57.30%	57.30%
Post shareholders | BellRing Common Stock
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Conversion of Stock, Shares Received	1.267788
Post | BellRing
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent	14.20%	14.20%	3.40%
Post | New BellRing Common Stock
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Distribution of ownership in subsidiary, shares	78,100,000
Distribution of ownership in subsidiary, percentage	80.10%
BellRing stockholders | BellRing
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent	28.50%	28.50%

Noncontrolling Interests, Equ_3

Noncontrolling Interests, Equity Interests and Related Party Transactions (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
	Aug. 08, 2022	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020	Mar. 10, 2022	Oct. 21, 2019	Oct. 01, 2018
Schedule of Equity Method Investments [Line Items]
Equity method (loss) earnings, net of tax		$ (67.1)	$ (43.9)	$ (30.9)
Related party		4.4	4.6
Related party		26.1	1.2
Equity method investments		4.1	70.7
Increase in additional paid-in capital related to net proceeds from IPO		0	305	0
Current investments held in trust		346.8	0
Investments held in trust		0	345
Redeemable noncontrolling interest		306.6	305
Initial public offering costs			17.9
Deferred Offering Costs		$ 10.7	10.7
Series A common stock included in each unit		1
Series B common stock included in each unit		1
Warrants included in each PHPC unit		0.333
Investment in BellRing		$ 94.8	0
Gain on investment in BellRing		$ (437.1)	0	0
PHPC Units
Schedule of Equity Method Investments [Line Items]
Common Unit, Issued		34,500,000
Share Price		$ 10
PHPC warrants
Schedule of Equity Method Investments [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights		11.50
PHPC Private Placement Units
Schedule of Equity Method Investments [Line Items]
Share Price		10
Proceeds from Issuance of Private Placement			$ 10.9
PHPC Forward Purchase Units
Schedule of Equity Method Investments [Line Items]
Share Price		$ 10
Maximum | PHPC Forward Purchase Units
Schedule of Equity Method Investments [Line Items]
Common Unit, Authorized			10,000,000
PHPC Sponsor | PHPC Units
Schedule of Equity Method Investments [Line Items]
Common Unit, Issued		4,000,000
PHPC Sponsor | Series F Common Stock
Schedule of Equity Method Investments [Line Items]
Common Stock, Shares		8,600,000
Additional Paid-in Capital
Schedule of Equity Method Investments [Line Items]
Initial public offering				455.6
Redeemable Noncontrolling Interest
Schedule of Equity Method Investments [Line Items]
Initial public offering		$ 0	$ 271.2
Redeemable noncontrolling interest		306.6	305	0
Initial public offering costs		0	16.9
Warrant Initial Valuation		0	(16.9)
Net earnings attributable to redeemable NCI, subsequent to IPO		6.7	5.8
Noncontrolling interest, Redemption value adjustment		(1.6)	0
Noncontrolling Interest, Change in Redemption Value		(5.1)	28
8th Avenue
Schedule of Equity Method Investments [Line Items]
Net Loss Available to 8th Avenue Common Shareholders		$ (251.3)	$ (60.6)	$ (38.9)
Equity Method Investment, Ownership Percentage		60.50%	60.50%	60.50%
Equity method loss available to Common Shareholders			$ (36.7)	$ (23.5)
Amortization of basis difference, net of tax			6.8	6.9
Equity method (loss) earnings, net of tax			(43.5)	(30.4)
Total Basis Difference Recognized							$ 70.3
Remaining Basis Difference to be Amortized			47.8
Net sales		$ 1,089	900.8	924.2
Gross profit		159.9	132.3	160
Net loss		(210.9)	(24.3)	(6.4)
Less: Preferred stock dividend		40.4	36.3	32.5
Current assets		337	282.8
Other assets		746.6	903
Total Assets		1,083.6	1,185.8
Current portion of long-term debt		6.5	6.5
Accounts payable and other current liabilities		166.3	131.7
Long-term debt		862.4	780
Other liabilities		54.1	63
Total Liabilities		1,089.3	981.2
Preferred stock		138.3	97.9
Other shareholders’ (deficit) equity		(144)	106.7
Shareholders’ (Deficit) Equity		(5.7)	204.6
Total Liabilities and Shareholders’ Equity		1,083.6	1,185.8
Revenue from Related Parties		8.1	6.7	5.7
Purchases from and Royalties paid to Related Party		$ 102.9	54.1	9.9
Alpen Food Company South Africa (Proprietary) Limited
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage		50%
Equity method (loss) earnings, net of tax		$ (0.5)	(0.4)	(0.5)
Weetabix East Africa Limited | Post
Schedule of Equity Method Investments [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent		50.10%
BellRing | Post
Schedule of Equity Method Investments [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent		3.40%			14.20%
Noncontrolling Interest, Common Stock, Amount		4,600,000			19,400,000
Noncontrolling Interest, Common Stock, Transfer	14,800,000
Other Assets | Alpen Food Company South Africa (Proprietary) Limited
Schedule of Equity Method Investments [Line Items]
Equity method investments		$ 4.1	4.1
Notes Receivable, Related Parties, Noncurrent		0.4	0.5
Other Liabilities | 8th Avenue
Schedule of Equity Method Investments [Line Items]
Due to Related Parties, Noncurrent		0.7	0.7
Equity Method Investments | 8th Avenue
Schedule of Equity Method Investments [Line Items]
Equity method investments		0	66.6
Accounts Receivable | 8th Avenue
Schedule of Equity Method Investments [Line Items]
Related party		4.4	4.6
Accounts Payable | 8th Avenue
Schedule of Equity Method Investments [Line Items]
Related party		26.1	1.2
Redeemable Noncontrolling Interest
Schedule of Equity Method Investments [Line Items]
Initial public offering costs			(16.9)
Selling, general and administrative expenses
Schedule of Equity Method Investments [Line Items]
MSA and Advisory Income		$ (3.2)	(3.5)	$ (3.9)
Initial public offering costs			(1)
PHPC
Schedule of Equity Method Investments [Line Items]
Increase in additional paid-in capital related to net proceeds from IPO			345
PHPC | PHPC Units
Schedule of Equity Method Investments [Line Items]
Increase in additional paid-in capital related to net proceeds from IPO			$ 345
PHPC | Common Class B
Schedule of Equity Method Investments [Line Items]
Par value of common stock		$ 0.0001
PHPC | Common Class A
Schedule of Equity Method Investments [Line Items]
Par value of common stock		0.0001
PHPC | Series F Common Stock
Schedule of Equity Method Investments [Line Items]
Par value of common stock		$ 0.0001
PHPC Sponsor | PHPC Private Placement Units
Schedule of Equity Method Investments [Line Items]
Common Unit, Issued			1,100,000
PHPC Sponsor | Maximum | PHPC Forward Purchase Units
Schedule of Equity Method Investments [Line Items]
Potential Proceeds from Issuance of Forward Purchase Agreement		$ 100
Public Shareholders | PHPC
Schedule of Equity Method Investments [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners		69%	69%
Post | PHPC
Schedule of Equity Method Investments [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent		31%	31%
Post | BellRing Brands, LLC
Schedule of Equity Method Investments [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners						71.20%
BellRing Brands, Inc. | Common Class B
Schedule of Equity Method Investments [Line Items]
Par value of common stock						$ 0.01
BellRing Brands, Inc. | Common Class A
Schedule of Equity Method Investments [Line Items]
Par value of common stock						$ 0.01
Common Stock, Shares, Issued						39,400,000
BellRing Brands, Inc. | BellRing Brands, LLC
Schedule of Equity Method Investments [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners						28.80%

Business Combinations (Details)

Business Combinations (Details) $ / shares in Units, £ in Millions, $ in Millions								12 Months Ended
	Apr. 05, 2022 GBP (£)	Apr. 05, 2022 USD ($)	Jun. 01, 2021 USD ($)	May 27, 2021 USD ($)	Feb. 01, 2021 USD ($)	Jan. 25, 2021 USD ($)	Jul. 01, 2020 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($) $ / shares	Sep. 30, 2020 USD ($) $ / shares
Business Acquisition
Business Combination, Acquisition Related Costs								$ 3.2	$ 6.4	$ 3.8
Pro forma net sales									5,184.3	5,182
Pro forma net earnings available to common stockholders									$ 96.9	$ (42.2)
Pro forma basic earnings per share | $ / shares									$ 1.51	$ (0.61)
Pro forma diluted earnings per share | $ / shares									$ 1.48	$ (0.61)
8th Avenue
Business Acquisition
Equity Method Investment, Ownership Percentage								60.50%	60.50%	60.50%
PL RTE Cereal Business
Business Acquisition
Payments to Acquire Businesses, Base Purchase Price			$ 85
Payments to Acquire Businesses, Gross			$ 88
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net									$ 99.5
Business Combination, Bargain Purchase, Gain, Statement of Income or Comprehensive Income [Extensible Enumeration]								Other Operating Income (Expense), Net
Business Combination, Bargain Purchase, Gain Recognized, Amount								$ 11.5
Egg Beaters
Business Acquisition
Payments to Acquire Businesses, Base Purchase Price				$ 50
Payments to Acquire Businesses, Gross				$ 50.6
Almark Foods
Business Acquisition
Payments to Acquire Businesses, Base Purchase Price					$ 52
Payments to Acquire Businesses, Gross					$ 51.3
Business Combinations, Measurement Period adjustment								0.3
Business Combination, Final Adjustment								1.3
Business Combination, Cash Received Related to WC Adjustment								2.9
Business Combination, Gain Related to Working Capital Adjustment								$ 1.2
Almark Foods | Receivables, net
Business Acquisition
Business Combination, Working Capital Receivable									3
Peter Pan
Business Acquisition
Payments to Acquire Businesses, Base Purchase Price						$ 102
Payments to Acquire Businesses, Gross						$ 103.4
Cash Acquired from Acquisition									2
Henningsen Foods
Business Acquisition
Payments to Acquire Businesses, Base Purchase Price							$ 20
Payments to Acquire Businesses, Gross							$ 22.7
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net										$ 32.6
Cash and cash equivalents										2.8
Business Combination, Working Capital Receivable										$ 1.8
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Inventory									0.7
Cash Acquired from Acquisition									1
Business Combination, Separately Recognized Transactions, Net Gains and Losses									$ 0.1
Business Combination, Bargain Purchase, Gain, Statement of Income or Comprehensive Income [Extensible Enumeration]										Other Operating Income (Expense), Net
Business Combination, Bargain Purchase, Gain Recognized, Amount										$ 11.7
Lacka Foods
Business Acquisition
Payments to Acquire Businesses, Base Purchase Price		$ 32.2
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net		32.9
Consideration Transferred		4.6
Business Combination, Acquired Cash		0.7
Lacka Foods | Euro Member Countries, Euro
Business Acquisition
Payments to Acquire Businesses, Base Purchase Price | £	£ 24.5
Consideration Transferred | £	3.5
Lacka Foods | Euro Member Countries, Euro | Maximum
Business Acquisition
Consideration Transferred | £	£ 3.5
Lacka Foods | Customer Relationships
Business Acquisition
Other intangible assets		$ 11.8
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	13 years	13 years
Lacka Foods | Trademarks and Brands
Business Acquisition
Other intangible assets		$ 8.9
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	13 years	13 years

Divestitures and Amounts Held_2

Divestitures and Amounts Held For Sale (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Assets	$ 0	$ 694.1
Proceeds from sale of property and assets held for sale	$ 18	$ 19.4	$ 2.5
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Operating Income (Expense), Net	Other Operating Income (Expense), Net	Other Operating Income (Expense), Net
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	$ 9.4	$ 0.5	$ 2.7
Refrigerated Retail | Williamette Egg Farms
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
(Gain) loss on sale of business	6.3
Disposal Group, Including Discontinued Operation, Assets	62.8
Disposition of Business, Adjustment, Working Capital	0.4
Proceeds from Divestiture of Businesses	56.1
Refrigerated Retail | Williamette Egg Farms | Receivables, net
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposition of Business, Working Capital Settlement Receivable	6
Foodservice | Klingerstown Equipment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of property and assets held for sale	$ 10.3
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Operating Income (Expense), Net
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	$ 9.8
Foodservice | Jefferson City Equipment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Operating Income (Expense), Net
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	$ 0.4
Weetabix Segment | Corby, United Kingdom facility
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal, Statement of Income or Comprehensive Income [Extensible Enumeration]		Other Operating Income (Expense), Net
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal		$ 0.7
Post Consumer Brands Segment | Clinton, Massachusetts facility
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal, Statement of Income or Comprehensive Income [Extensible Enumeration]		Other Operating Income (Expense), Net	Other Operating Income (Expense), Net
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal		$ 0.1	$ 2.6
Post Consumer Brands Segment | Asheboro, North Carolina facility
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal, Statement of Income or Comprehensive Income [Extensible Enumeration]		Other Operating Income (Expense), Net	Other Operating Income (Expense), Net
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal		$ 0.1	$ 0.1

Goodwill (Details)

Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Goodwill [Line Items]
Goodwill	$ 4,349.6	$ 4,501.6
Operating Segments
Goodwill [Line Items]
Goodwill (gross)	5,007.4	5,159.4	$ 5,030.5
Accumulated impairment losses	(657.8)	(657.8)	(657.8)
Goodwill	4,349.6	4,501.6	$ 4,372.7
Goodwill acquired	14.2	88.8
Goodwill, Sale of Business	(4.2)
Currency translation adjustment	$ (162)	$ 40.1
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount	10%	15%	13%
Operating Segments | Cheese and dairy
Goodwill [Line Items]
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount	6.50%
Operating Segments | Post Consumer Brands Segment
Goodwill [Line Items]
Goodwill (gross)	$ 2,066.8	$ 2,067.1	$ 2,011.8
Accumulated impairment losses	(609.1)	(609.1)	(609.1)
Goodwill	1,457.7	1,458	1,402.7
Goodwill acquired	0	55.1
Goodwill, Sale of Business	0
Currency translation adjustment	(0.3)	0.2
Operating Segments | Weetabix Segment
Goodwill [Line Items]
Goodwill (gross)	781.6	929.4	889.5
Accumulated impairment losses	0	0	0
Goodwill	781.6	929.4	889.5
Goodwill acquired	13.9	0
Goodwill, Sale of Business	0
Currency translation adjustment	(161.7)	39.9
Operating Segments | Foodservice Segment
Goodwill [Line Items]
Goodwill (gross)	1,355.3	1,355	1,335.6
Accumulated impairment losses	0	0	0
Goodwill	1,355.3	1,355	$ 1,335.6
Goodwill acquired	0.3	19.4
Goodwill, Sale of Business	0
Currency translation adjustment	0	$ 0
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount		11%	4%
Operating Segments | Refrigerated Retail Segment
Goodwill [Line Items]
Goodwill (gross)	803.7	$ 807.9	$ 793.6
Accumulated impairment losses	(48.7)	(48.7)	(48.7)
Goodwill	755	759.2	$ 744.9
Goodwill acquired	0	14.3
Goodwill, Sale of Business	(4.2)
Currency translation adjustment	$ 0	$ 0
Operating Segments | Refrigerated Retail
Goodwill [Line Items]
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount	8.50%

Income Taxes (Loss) Earnings be

Income Taxes (Loss) Earnings before Income Taxes and Equity Method Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Earnings before Income Taxes and Equity Method Loss [Abstract]
Domestic	$ 799.9	$ 105.9	$ (146.5)
Foreign	95.4	108.1	100.6
Earnings (Loss) before Income Taxes and Equity Method Loss	895.3	214	(45.9)
Income tax expense (benefit)	$ 85.7	$ 58.2	$ (21.3)
Effective Income Tax Rate Reconciliation, Percent	9.60%	27.20%	(46.40%)

Income Taxes - Income tax (bene

Income Taxes - Income tax (benefit) expense (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Current
Federal	$ 71.1	$ (20.3)	$ 9.2
State	11.1	(0.2)	4.6
Foreign	13.2	10.5	9
Current	95.4	(10)	22.8
Deferred
Federal	(9.7)	22.6	(45.9)
State	0	3.4	(14.6)
Foreign	0	42.2	16.4
Deferred	(9.7)	68.2	(44.1)
Income tax expense (benefit)	$ 85.7	$ 58.2	$ (21.3)

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Income Tax (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosures
Income Tax Reconciliation Threshold for Other Expenses	5%	5%	5%
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Computed tax (21%)	$ 188	$ 44.9	$ (9.6)
Enacted tax law changes, including the Tax Act	0.9	40	10.2
Effective Income Tax Rate Reconciliation, Gain on investment in BellRing	(91.8)	0	0
Non-deductible compensation	5.9	5.4	4.5
State income tax, net of effect on federal tax	10.3	1.7	(7.8)
Valuation allowances	1.4	2.9	6.1
Net losses and basis difference attributable to equity method investment	(14.1)	(9.2)	(6.5)
Income tax credits	(1.9)	(1.5)	(2.6)
Rate differential on foreign income	(10.2)	(11)	(10.7)
Excess tax benefits for share-based payments	(3.6)	(6.1)	(1.3)
Gain on bargain purchase	0	(2.4)	(2.5)
Enhanced deduction for food donations	(1)	(0.8)	(1.3)
Return-to-provision and changes in prior year accruals	(0.5)	(2.8)	(1.4)
Other, net (none in excess of 5% of statutory tax)	2.3	(2.9)	1.6
Income tax expense (benefit)	$ 85.7	$ 58.2	$ (21.3)
UNITED STATES
Income Tax Disclosures
Federal Income Tax Rate	21%	21%	21%

Income Taxes - Deferred Taxes (

Income Taxes - Deferred Taxes (Details) - USD ($)	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Components of Deferred Tax Liabilities [Abstract]
Operating Loss Carryforwards	$ 3.4
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ (6,100,000)	$ 500,000	$ 8,500,000
Maximum
Components of Deferred Tax Liabilities [Abstract]
Operating Loss Carryforwards, Expiration	10 years
Domestic Tax Authority
Components of Deferred Tax Liabilities [Abstract]
Operating Loss Carryforwards	$ 1,900,000
State and Local Jurisdiction
Components of Deferred Tax Assets [Abstract]
Disallowed Interest Carryforwards	4,800,000
Components of Deferred Tax Liabilities [Abstract]
Operating Loss Carryforwards	13,500,000
Foreign Tax Authority
Components of Deferred Tax Liabilities [Abstract]
Operating Loss Carryforwards	5,300,000
Assets | Noncurrent
Components of Deferred Tax Assets [Abstract]
Derivatives and mark-to-market adjustments	34,900,000	100,000,000
Disallowed Interest Carryforwards	55,400,000	34,200,000
Lease liabilities	35,800,000	31,900,000
Net operating loss and credit carryforwards	24,100,000	29,100,000
Stock-based and deferred compensation	19,900,000	17,500,000
Accrued liabilities	7,000,000	9,400,000
Accrued vacation, incentive and severance	6,200,000	8,200,000
Inventory	8,800,000	4,100,000
Basis difference attributable to equity method investment	4,600,000
Other items	5,500,000	5,600,000
Deferred Tax Assets, Gross, Total	202,200,000	240,000,000
Valuation allowance	(35,500,000)	(41,600,000)
Total deferred taxes	166,700,000	198,400,000
Components of Deferred Tax Liabilities [Abstract]
Basis difference attributable to equity method investment	4,600,000
Liability | Noncurrent
Components of Deferred Tax Assets [Abstract]
Basis difference attributable to equity method investment	0	(11,800,000)
Components of Deferred Tax Liabilities [Abstract]
Intangible assets	(611,400,000)	(643,500,000)
Property	(197,600,000)	(218,700,000)
ROU assets	(32,900,000)	(30,000,000)
Pension and other postretirement benefits	(11,400,000)	(21,700,000)
Basis difference attributable to equity method investment	0	(11,800,000)
Other items	(1,800,000)	(1,800,000)
Deferred Tax Liabilities, Gross	(855,100,000)	(927,500,000)
Net Assets | Noncurrent
Components of Deferred Tax Assets [Abstract]
Derivatives and mark-to-market adjustments	34,900,000	100,000,000
Disallowed Interest Carryforwards	55,400,000	34,200,000
Lease liabilities	35,800,000	31,900,000
Net operating loss and credit carryforwards	24,100,000	29,100,000
Stock-based and deferred compensation	19,900,000	17,500,000
Accrued liabilities	7,000,000	9,400,000
Accrued vacation, incentive and severance	6,200,000	8,200,000
Inventory	8,800,000	4,100,000
Basis difference attributable to equity method investment	4,600,000	(11,800,000)
Other items	3,700,000	3,800,000
Valuation allowance	(35,500,000)	(41,600,000)
Components of Deferred Tax Liabilities [Abstract]
Intangible assets	(611,400,000)	(643,500,000)
Property	(197,600,000)	(218,700,000)
ROU assets	(32,900,000)	(30,000,000)
Pension and other postretirement benefits	(11,400,000)	(21,700,000)
Basis difference attributable to equity method investment	4,600,000	(11,800,000)
Deferred Tax Liabilities, Gross	(652,900,000)	(687,500,000)
Total deferred tax liabilities, gross	$ (688,400,000)	$ (729,100,000)

Income Taxes - Income Taxes Nar

Income Taxes - Income Taxes Narrative (Details) - USD ($)	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosures
Operating Loss Carryforwards	$ 3.4
Operating Loss Carryforwards, Limitations on Usage	13,400,000
Undistributed Earnings of Foreign Subsidiaries	90,000,000
Domestic Tax Authority
Income Tax Disclosures
Operating Loss Carryforwards	1,900,000
Foreign Tax Authority
Income Tax Disclosures
Operating Loss Carryforwards	$ 5,300,000
UNITED KINGDOM
Income Tax Disclosures
Newly Enacted Tax Rate	19%		17%
Provisional Tax Rate	25%		19%
Change in deferred tax rates	$ 900,000	$ 40,000,000	$ 13,000,000

Income Taxes - Unrecognized tax

Income Taxes - Unrecognized tax benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Unrecognized Tax Benefits	$ 12.5	$ 8.3	$ 8.6
Unrecognized Tax Benefits, Increases Resulting from Current Period Tax Positions	0.1	0.3	0.2
Unrecognized Tax Benefits, Decreases Resulting from Prior Period Tax Positions	0	5.2	0
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities	(0.9)	(1.3)	(0.5)
Unrecognized Tax Benefits	11.7	12.5	8.3
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	6.5
Decrease in Unrecognized Tax Benefits is Reasonably Possible	0.2
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	0.1	(0.5)	$ 0
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	$ 0.6	$ 0.5

Earnings per Share (Details)

Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share, Diluted
Net Income (Loss) from continuing operations, net of tax and noncontrolling interest		$ 735	$ 104.9	$ (56.5)
Temporary Equity, Accretion to Redemption Value, Adjustment		0	(11)	0
Net earnings (loss) from continuing operations for basic earnings (loss) per share		735	93.9	(56.5)
Impact of interest expense, net of tax, related to convertible senior notes		1.5	0	0
Net earnings (loss) from continuing operations for diluted earnings (loss) per share		736.5	93.9	(56.5)
Net earnings from discontinued operations for basic earnings		21.6	61.8	57.3
Dilutive impact of BellRing net earnings		0	(0.1)	0
Net earnings from discontinued operations for diluted earnings		21.6	61.7	57.3
Net Earnings (Loss) Available to Common Stockholders, Basic		756.6	155.7	0.8
Net Income (Loss) Available to Common Stockholders, Diluted		$ 758.1	$ 155.6	$ 0.8
Weighted-average shares for basic earnings per share		60.9	64.2	68.9
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities		0.7	0	0
Weighted Average Number of Shares Outstanding, Diluted, Adjustment		1.8	1.1	0
Weighted-average shares for diluted earnings per share		62.7	65.3	68.9
Earnings (Loss) from Continuing Operations, Per Basic Share		$ 12.07	$ 1.46	$ (0.82)
Earnings (Loss) from Continuing Operations, Per Diluted Share		11.75	1.44	(0.82)
Discontinued Operation, Earnings (Loss) from Discontinued Operation, Net of Tax, Per Basic Share		0.35	0.96	0.83
Discontinued Operation, Earnings (Loss) from Discontinued Operation, Net of Tax, Per Diluted Share		0.34	0.94	0.83
Basic earnings per common share (in usd per share)		12.42	2.42	0.01
Diluted earnings per common share (in usd per share)		$ 12.09	$ 2.38	$ 0.01
Stock Options
Earnings Per Share, Diluted
Effect of dilutive securities		0.3	0.6	0
Stock Appreciation Rights
Earnings Per Share, Diluted
Effect of dilutive securities		0.1	0.1	0
Restricted Stock
Earnings Per Share, Diluted
Effect of dilutive securities		0.5	0.3	0
Earnings-based performance shares
Earnings Per Share, Diluted
Effect of dilutive securities		0.1	0	0
Market-based performance shares
Earnings Per Share, Diluted
Effect of dilutive securities		0.1	0.1	0

Earnings per Share Antidilutive

Earnings per Share Antidilutive shares excluded from earnings per share (Details) - shares shares in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	0	1.6
Stock Appreciation Rights
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	0	0.1
Restricted Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0.3	0	0.5
Performance-based Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0.1	0	0.2

Supplemental Operations State_3

Supplemental Operations Statement and Cash Flow Information (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Supplemental Operations Statement and Cash Flow Information [Abstract]
Advertising expenses	$ 93.2	$ 112.3	$ 113.1
Research and development expenses	18.9	21.9	19.1
Interest income	(4.4)	(0.6)	(6.2)
Interest paid	320	348.2	300
Income taxes paid	45.8	45.6	44.4
Accrued additions to property	$ 36.4	$ 38.3	$ 29.8

Supplemental Balance Sheet In_3

Supplemental Balance Sheet Information (Details) - USD ($) $ in Millions	Sep. 30, 2022	Sep. 30, 2021
Receivables, net
Trade	$ 499.4	$ 374.8
Income tax receivable	17.4	57.2
Related party	4.4	4.6
Other	25.3	18
Gross receivables	546.5	454.6
Allowance for credit losses	(2.3)	(2.2)
Receivables, net	544.2	452.4
Inventories
Raw materials and supplies	130.9	99.6
Work in process	21.1	19.2
Finished products	361.9	318.7
Flocks	35.2	39.1
Inventories	549.1	476.6
Other Assets
Pension asset	93.9	153.4
Operating ROU assets	122.9	115.5
Other investments	26.9	22.9
Derivative assets	3	29.1
Other	20.1	27.1
Other Assets	266.8	348
Accounts Payable
Trade	362.1	369.1
Book cash overdrafts	53.3	1.5
Related party	26.1	1.2
Other	11.2	12.4
Accounts payable	452.7	384.2
Current Liabilities
Advertising and promotion	47.2	40.2
Accrued interest	69.5	68.1
Accrued compensation	63.4	41.7
Hedging liabilities	25.9	127.7
Operating lease liabilities	25.5	23.5
Accrued freight	25.1	24
Other accrued taxes	19.1	21.6
Other	94.3	68.2
Other current liabilities	370	415
Other Liabilities
Pension and other postretirement benefit obligations	45.6	64.2
Derivative liabilities	49.1	256
Accrued compensation	33.1	36.1
Operating lease liabilities	113.7	105.2
Other	25.4	46.4
Other Liabilities	$ 266.9	$ 507.9

Derivative Financial Instrume_3

Derivative Financial Instruments and Hedging Derivative Financial Instruments and Hedging Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2020	Sep. 30, 2021
Portion Designated as Hedging Instruments | Currency Swap
Derivative [Line Items]
Derivative, Notional Amount of Terminated Contracts		$ 448.7
Not Designated as Hedging Instrument | Interest rate swap
Derivative [Line Items]
Derivative, Notional Amount	$ 200		$ 200
Not Designated as Hedging Instrument | Interest rate swap, rate lock swaps
Derivative [Line Items]
Derivative, Notional amount of terminated contracts	700
Derivative, Cash Paid for Termination	17
Derivative, Notional Amount	849.3		1,549.3
Not Designated as Hedging Instrument | Interest rate swap, options
Derivative [Line Items]
Derivative, Notional Amount	$ 332.6		$ 0
Not Designated as Hedging Instrument | Interest expense, net | Interest rate swap
Derivative [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income		(7.2)
Accumulated OCI | Portion Designated as Hedging Instruments | Currency Swap
Derivative [Line Items]
Derivative, Cash Received on Hedge		$ 50.3

Derivative Financial Instrume_4

Derivative Financial Instruments and Hedging (Details) - USD ($) $ in Millions	Sep. 30, 2022	Sep. 30, 2021
Level 2
Derivatives, Fair Value
Asset Derivatives:	$ 32.9	$ 65.5
Liability Derivatives:	75	383.7
Commodity contracts | Level 2 | Prepaid expenses and other current assets
Derivatives, Fair Value
Asset Derivatives:	12.9	16.3
Commodity contracts | Level 2 | Other Assets
Derivatives, Fair Value
Asset Derivatives:	0.5	2.9
Commodity contracts | Level 2 | Other current liabilities
Derivatives, Fair Value
Liability Derivatives:	1.5	2.8
Commodity contracts | Not Designated as Hedging Instrument
Derivatives, Fair Value
Derivative, Notional Amount	145	56.4
Energy contracts | Level 2 | Prepaid expenses and other current assets
Derivatives, Fair Value
Asset Derivatives:	13.6	20.1
Energy contracts | Level 2 | Other Assets
Derivatives, Fair Value
Asset Derivatives:	0	2
Energy contracts | Level 2 | Other current liabilities
Derivatives, Fair Value
Liability Derivatives:	1.8	0
Energy contracts | Not Designated as Hedging Instrument
Derivatives, Fair Value
Derivative, Notional Amount	23.7	45.9
Foreign exchange contracts | Level 2 | Other current liabilities
Derivatives, Fair Value
Liability Derivatives:	0.1	0
Foreign exchange contracts | Not Designated as Hedging Instrument
Derivatives, Fair Value
Derivative, Notional Amount	3.2	0
Interest rate swap | Level 2 | Prepaid expenses and other current assets
Derivatives, Fair Value
Asset Derivatives:	3.4	0
Interest rate swap | Level 2 | Other Assets
Derivatives, Fair Value
Asset Derivatives:	2.5	24.2
Interest rate swap | Level 2 | Other current liabilities
Derivatives, Fair Value
Liability Derivatives:	22.5	124.9
Interest rate swap | Level 2 | Other liabilities
Derivatives, Fair Value
Liability Derivatives:	48.1	246.8
Interest rate swap | Not Designated as Hedging Instrument
Derivatives, Fair Value
Derivative, Notional Amount	200	200
Interest rate swap, rate lock swaps | Not Designated as Hedging Instrument
Derivatives, Fair Value
Derivative, Notional Amount	849.3	1,549.3
Interest rate swap, options | Not Designated as Hedging Instrument
Derivatives, Fair Value
Derivative, Notional Amount	332.6	0
PHPC warrants | Level 2 | Other liabilities
Derivatives, Fair Value
Liability Derivatives:	1	9.2
PHPC warrants | Not Designated as Hedging Instrument
Derivatives, Fair Value
Derivative, Notional Amount	$ 16.9	$ 16.9

Derivative Financial Instrume_5

Derivative Financial Instruments and Hedging Loss (Gain) recognized in earnings from derivative instruments (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Derivative Instruments, Loss (Gain) [Line Items]
(Income) expense on swaps, net	$ (268)	$ (122.8)	$ 187.1
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	(7.1)	(2.3)	(8.2)
Net gain (loss) on derivatives	0	0	22.5
Commodity contracts
Derivative Instruments, Loss (Gain) [Line Items]
(Gain) Loss Recognized in Statement of Operations	$ (32.2)	$ (11.3)	$ 3.8
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Cost of goods sold	Cost of goods sold	Cost of goods sold
Energy contracts
Derivative Instruments, Loss (Gain) [Line Items]
(Gain) Loss Recognized in Statement of Operations	$ (28.5)	$ (43.1)	$ 21.6
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Cost of goods sold	Cost of goods sold	Cost of goods sold
Foreign exchange contracts
Derivative Instruments, Loss (Gain) [Line Items]
(Gain) Loss Recognized in Statement of Operations	$ 0.1	$ 0.1	$ (0.1)
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Selling, general and administrative expenses	Selling, general and administrative expenses	Selling, general and administrative expenses
Interest rate swap
Derivative Instruments, Loss (Gain) [Line Items]
(Income) expense on swaps, net	$ (268)	$ (122.8)	$ 187.1
PHPC warrants
Derivative Instruments, Loss (Gain) [Line Items]
(Gain) Loss Recognized in Statement of Operations	$ (8.2)	$ (7.7)	$ 0
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Portion Designated as Hedging Instruments | Currency Swap
Derivative Instruments, Loss (Gain) [Line Items]
Losses (Gains) Reclassified to Net Earnings			$ 0
Derivative Instrument, Gain Reclassified from AOCI into Income, Effective Portion, Statement of Income or Comprehensive Income [Extensible Enumeration]			(Income) expense on swaps, net
Portion Designated as Hedging Instruments | Currency Swap | (Income) expense on swaps, net
Derivative Instruments, Loss (Gain) [Line Items]
Net gain (loss) on derivatives			$ (32.2)
Portion Designated as Hedging Instruments | Interest rate swap
Derivative Instruments, Loss (Gain) [Line Items]
Derivative Instruments, Gain Reclassified from Accumulated OCI into Income, Effective Portion			7.2
Portion Designated as Hedging Instruments | Interest rate swap | Interest expense, net
Derivative Instruments, Loss (Gain) [Line Items]
Net gain (loss) on derivatives			$ (0.6)
Derivative Instrument, Gain Reclassified from AOCI into Income, Effective Portion, Statement of Income or Comprehensive Income [Extensible Enumeration]			Interest expense, net

Derivative Financial Instrume_6

Derivative Financial Instruments and Hedging Derivative and Financial Instruments designated as hedges and Pledged Collateral (Details) - USD ($) $ in Millions	Sep. 30, 2022	Sep. 30, 2021
Derivative [Line Items]
Accumulated Other Comprehensive Income, Cumulative Changes in Net Loss from Hedges, Before Tax	$ 99.5	$ 99.5
AOCI, Cash Flow Hedge, Cumulative Gain (Loss), after Tax	74.9	74.9
Collateral Already Posted	$ 2.8	$ 6.4

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020	Mar. 10, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Deferred compensation investment	$ 12	$ 15.5
Derivative Asset	Other assets	Other assets
Equity securities	$ 32.1	$ 28.9
Investment in BellRing	94.8	0
Assets, Fair Value Disclosure	171.8	109.9
Deferred compensation liabilities	33.7	36
Derivative Liability	75	383.7
Liabilities, Fair Value Disclosure	108.7	419.7
(Losses) gains related to assets and liabilities held for sale	$ 9.4	$ 0.5	$ 2.7
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Other liabilities	Other liabilities
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Deferred compensation investment	$ 12	$ 15.5
Derivative Asset	Other assets	Other assets
Equity securities	$ 32.1	$ 28.9
Investment in BellRing	94.8	0
Assets, Fair Value Disclosure	138.9	44.4
Deferred compensation liabilities	0	0
Derivative Liability	1	9.2
Liabilities, Fair Value Disclosure	$ 1	$ 9.2
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Other liabilities	Other liabilities
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Deferred compensation investment	$ 0	$ 0
Derivative Asset	Other assets	Other assets
Equity securities	$ 0	$ 0
Investment in BellRing	0	0
Assets, Fair Value Disclosure	32.9	65.5
Deferred compensation liabilities	33.7	36
Derivative Liability	74	374.5
Liabilities, Fair Value Disclosure	107.7	410.5
Debt, Fair Value Disclosure	$ 5,171	$ 6,596.7
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Other liabilities	Other liabilities
Level 2 | Senior Notes | 2.50% convertible senior notes maturing in August 2027
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt, Fair Value Disclosure	$ 566.1	$ 0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of assets held-for-sale	0.1	0	$ 7.3
Proceeds from Sale of Assets and Liabilities Held for Sale	(10.3)	(7.9)
(Losses) gains related to assets and liabilities held for sale	9.4	0.5
Translation Adjustment Functional to Reporting Currency, Increase (Decrease), Gross of Tax		$ 0.1
Transfers into assets held for sale	$ 1
BellRing | Post
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Noncontrolling Interest, Ownership Percentage by Parent	3.40%			14.20%

Leases (Details)

Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Lessee, Lease, Description [Line Items]
Operating Lease, Weighted Average Remaining Lease Term	9 years	9 years	7 years
Operating Lease, Weighted Average Discount Rate, Percent	5.26%	4.70%	4.46%
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Other assets	Other assets
Operating ROU assets	$ 122.9	$ 115.5
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other current liabilities	Other current liabilities
Operating lease liabilities	$ 25.5	$ 23.5
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other liabilities	Other liabilities
Operating lease liabilities	$ 113.7	$ 105.2
Operating Lease, Liability, Statement of Financial Position [Extensible List]	Other Liabilities	Other Liabilities
Operating Lease, Liability	$ 139.2	$ 128.7
Lessee, Operating Lease, Liability, Payments, Due Year One	32.1
Lessee, Operating Lease, Liability, Payments, Due Year Two	26.3
Lessee, Operating Lease, Liability, Payments, Due Year Three	20.4
Lessee, Operating Lease, Liability, Payments, Due Year Four	18.9
Lessee, Operating Lease, Liability, Payments, Due Year Five	14.5
Lessee, Operating Lease, Liability, Payments, Due after Year Five	64.3
Lessee, Operating Lease, Liability, Payments, Due	176.5
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	37.3
Operating Lease, Cost	45.5	40.1	$ 38
Variable Lease, Cost	5.2	4.8	4.5
Short-term Lease, Cost	9.4	7.5	7.4
Operating Lease, Payments	29.6	28.4	26
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 20.7	33.8	$ 5.3
Almark Foods
Lessee, Lease, Description [Line Items]
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability		$ 27.7
Minimum
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	1 year
Maximum
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	54 years

Long Term Debt (Details)

Long Term Debt (Details) $ / shares in Units, shares in Millions			3 Months Ended					12 Months Ended
	Aug. 12, 2022 shares	Jul. 26, 2022 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Sep. 30, 2022 USD ($) d $ / shares shares	Sep. 30, 2021 USD ($) shares	Sep. 30, 2020 USD ($) shares	Mar. 31, 2021 USD ($)	Mar. 31, 2020 USD ($)	Oct. 21, 2019 USD ($)	Oct. 11, 2019 USD ($)
Debt Instrument
Long-term Debt and Capital Lease Obligations, Including Current Maturities								$ 5,969,300,000	$ 6,447,700,000
Current portion of long-term debt								1,100,000	1,100,000
Unamortized Debt Issuance Expense								50,100,000	47,200,000
Plus: Unamortized premium, net								38,500,000	42,200,000
Total long-term debt								$ 5,956,600,000	6,441,600,000
Debt Covenant, Leverage Ratio								4.25
Debt Covenant, Percentage of Revolving Credit Commitments								30%
Gross Repayments of Long-term debt								$ 1,661,100,000	1,698,300,000	$ 2,932,800,000
(Gain) loss on extinguishment of debt, net								(72,600,000)	93,200,000	72,900,000
Premium and Debt Extinguishment Costs Paid								24,100,000	74,300,000	49,800,000
Payments of Debt Issuance Costs								$ 26,400,000	16,800,000	35,700,000
Debt Instruments, Covenant Compliance, Percentage of Revolving Credit Commitments								30%
Write off of Debt Issuance Costs								$ (9,400,000)	(500,000)	(2,700,000)
Repayments of Long-term Debt								1,563,300,000	1,698,300,000	2,932,800,000
Refund of debt issuance costs								0	$ 0	$ 15,300,000
Long-Term Debt, Maturity, Year One								1,100,000
Long-Term Debt, Maturity, Year Two								1,100,000
Long-Term Debt, Maturity, Year Three								1,200,000
Long-Term Debt, Maturity, Year Four								1,200,000
Long-Term Debt, Maturity, Year Five								1,035,600,000
Estimated future interest payments on debt								1,395,600,000
Estimated future interest payments on debt, next twelve months								$ 284,100,000
Debt Instrument, Convertible, Threshold Consecutive Trading Days | d								5
Debt Instrument, Convertible, Earliest Date								May 15, 2027
Debt Instrument, Convertible, Latest Date								Aug. 15, 2027
Common Stock
Debt Instrument
Treasury Stock, Shares, Acquired | shares	1.1							4.9	4	6.1
Noncash
Debt Instrument
Gross Repayments of Long-term debt								$ 1,182,300,000		$ 1,225,000,000
Level 2
Debt Instrument
Debt, Fair Value Disclosure								$ 5,171,000,000	$ 6,596,700,000
Minimum
Debt Instrument
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger								98%
Maximum
Debt Instrument
Gross Repayments of Long-term debt								$ 450,000,000
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger								130%
Revolving Credit Facility
Debt Instrument
Debt Covenant, Maximum Undischarged Judgments								$ 100,000,000
Gross Repayments of Long-term debt										500,000,000
Line of Credit Facility, Current Borrowing Capacity								750,000,000
Letters of Credit Outstanding, Amount								19,700,000	19,200,000
Line of Credit Facility, Remaining Borrowing Capacity								730,300,000	730,800,000
Payments of Financing Costs								$ 400,000
Revolving Credit Facility | High-End Ratio
Debt Instrument
Debt Covenant, Leverage Ratio								3
Revolving Credit Facility | Low-End Ratio
Debt Instrument
Debt Covenant, Leverage Ratio								1.50
Revolving Credit Facility | Minimum
Debt Instrument
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage								0.25%
Revolving Credit Facility | Maximum
Debt Instrument
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage								0.375%
Line of Credit
Debt Instrument
Line of Credit Facility, Current Borrowing Capacity								$ 75,000,000
Credit Agreement
Debt Instrument
Gross Repayments of Long-term debt										0
Payments of Debt Issuance Costs										3,600,000
2020 Bridge Loan | Noncash
Debt Instrument
Gross Repayments of Long-term debt										1,225,000,000
Proceeds from issuance of unsecured debt										1,225,000,000
Term Loan
Debt Instrument
Long-term Debt													$ 1,309,500,000
Gross Repayments of Long-term debt										1,309,500,000
Term Loan | Incremental Term Loan
Debt Instrument
Gross Repayments of Long-term debt								840,000,000
Term Loan | Incremental Term Loan | Noncash
Debt Instrument
Gross Repayments of Long-term debt								840,000,000
Term Loan | Second Incremental Term Loan
Debt Instrument
Gross Repayments of Long-term debt								107,700,000
Loans Payable to Bank								450,000,000
Term Loan | Second Incremental Term Loan | Noncash
Debt Instrument
Gross Repayments of Long-term debt								342,300,000
Municipal Bonds
Debt Instrument
Long-term Debt								6,400,000	7,500,000
Gross Repayments of Long-term debt								1,100,000	1,000,000	1,100,000
Senior Notes | 5.50% Senior Notes Maturing in December 2029
Debt Instrument
Long-term Debt								$ 1,235,000,000	750,000,000
Senior Notes				$ 750,000,000
Debt Instrument, Interest Rate, Stated Percentage								5.50%
Gross Repayments of Long-term debt								$ 15,000,000
Debt Instrument, Increase, Additional Borrowings				743,000,000				514,000,000
Payments of Debt Issuance Costs				$ 7,000,000				$ 3,500,000
Debt Instrument, Issuance Price, Percentage of Par Value								103.50%
Senior Notes | 5.625% Senior Notes Maturing January 2028
Debt Instrument
Long-term Debt								$ 940,900,000	940,900,000
Senior Notes					$ 1,000,000,000
Debt Instrument, Interest Rate, Stated Percentage								5.625%
Debt Instrument, Increase, Additional Borrowings					990,600,000
Payments of Debt Issuance Costs					$ 9,400,000
Senior Notes | 5.50% Senior Notes maturing March 2025
Debt Instrument
Gross Repayments of Long-term debt										1,000,000,000
Senior Notes | 5.75% Senior Notes Maturing March 2027
Debt Instrument
Long-term Debt								$ 459,300,000	1,299,300,000
Senior Notes							$ 750,000,000
Debt Instrument, Interest Rate, Stated Percentage								5.75%
Gross Repayments of Long-term debt								$ 840,000,000
Debt Instrument, Redemption Price, Percentage								102.875%
Gross Repayments of Long-term debt, percentage								65%
Senior Notes | 8.00% Senior Notes Maturing in July 2025
Debt Instrument
Gross Repayments of Long-term debt										122,200,000
Senior Notes | 5.50% and 5.75% Senior Notes
Debt Instrument
Debt Instrument, Increase, Additional Borrowings							739,500,000	$ 559,100,000
Payments of Debt Issuance Costs							$ 10,500,000	$ 15,900,000
Senior Notes | Additional Issuance of 5.75% Senior Notes Maturing in March 2027
Debt Instrument
Senior Notes						$ 750,000,000
Debt Instrument, Interest Rate, Stated Percentage								5.75%
Debt Instrument, Increase, Additional Borrowings						784,000,000
Payments of Debt Issuance Costs						$ 7,200,000
Debt Instrument, Issuance Price, Percentage of Par Value						105.50%
Senior Notes | 5.00% Senior Notes Maturing in August 2026
Debt Instrument
Gross Repayments of Long-term debt									1,697,300,000
Senior Notes | 4.625% Senior Notes Maturing in April 2030
Debt Instrument
Long-term Debt								$ 1,482,200,000	1,650,000,000
Debt Instrument, Interest Rate, Stated Percentage								4.625%
Gross Repayments of Long-term debt		$ 139,800,000						$ 167,800,000
Gross Repayments of Long-term debt, percentage								8%
Debt Instrument, Issuance Price, Percentage of Par Value								87%
Debt Issuance, Tender Premium, Percentage of Par Value								5%
Senior Notes | 4.625% Senior Notes Maturing in April 2030 | Minimum
Debt Instrument
Debt Instrument, Issuance Price, Percentage of Par Value								81%
Senior Notes | 4.625% Senior Notes Maturing in April 2030 | Maximum
Debt Instrument
Debt Instrument, Issuance Price, Percentage of Par Value								88%
Senior Notes | Original Issuance of 4.625% Senior Notes Maturing in April 2030
Debt Instrument
Long-term Debt												$ 1,250,000,000
Debt Instrument, Increase, Additional Borrowings										1,241,000,000
Payments of Debt Issuance Costs										9,000,000
Senior Notes | Additional Issuance of 4.625% Senior Notes Maturing in April 2030
Debt Instrument
Long-term Debt			$ 400,000,000							400,000,000
Debt Instrument, Increase, Additional Borrowings										417,500,000
Payments of Debt Issuance Costs										4,500,000
Debt Instrument, Issuance Price, Percentage of Par Value			105.50%
Senior Notes | 4.50% Senior Notes Maturing in September 2031
Debt Instrument
Long-term Debt								$ 1,270,500,000	1,800,000,000		$ 1,800,000,000
Debt Instrument, Interest Rate, Stated Percentage								4.50%
Gross Repayments of Long-term debt		$ 381,800,000						$ 529,500,000
Debt Instrument, Increase, Additional Borrowings									1,783,200,000
Payments of Debt Issuance Costs									16,800,000
Gross Repayments of Long-term debt, percentage								22%
Debt Instrument, Issuance Price, Percentage of Par Value								86%
Debt Issuance, Tender Premium, Percentage of Par Value								5%
Payment of tender fees								$ 1,700,000
Senior Notes | 4.50% Senior Notes Maturing in September 2031 | Minimum
Debt Instrument
Debt Instrument, Issuance Price, Percentage of Par Value								80%
Senior Notes | 4.50% Senior Notes Maturing in September 2031 | Maximum
Debt Instrument
Debt Instrument, Issuance Price, Percentage of Par Value								87%
Senior Notes | 2.50% convertible senior notes maturing in August 2027
Debt Instrument
Long-term Debt								$ 575,000,000	0
Senior Notes								575,000,000
Unamortized Debt Issuance Expense								$ 15,500,000
Debt Instrument, Interest Rate, Stated Percentage								2.50%
Long-Term Debt, Maturity, Year Five								$ 575,000,000
Debt Instrument, Convertible, Conversion Price | $ / shares								$ 106.10
Debt Instrument, Convertible, Conversion Ratio								9.4248
Long-Term Debt, Fair Value								$ 559,500,000
Debt Instrument, Issued, Principal								$ 1,000
Debt Instrument, Convertible, Threshold Trading Days | d								10
Senior Notes | 2.50% convertible senior notes maturing in August 2027 | Level 2
Debt Instrument
Debt, Fair Value Disclosure								$ 566,100,000	0
Senior Notes | Additional 5.50% Senior Notes Maturing in December 2029
Debt Instrument
Long-term Debt								500,000,000
Senior Notes | 4.50% and 4.625% Senior Notes
Debt Instrument
Gross Repayments of Long-term debt								$ 450,000,000
Base Rate | Revolving Credit Facility | Minimum
Debt Instrument
Debt Instrument, Basis Spread on Variable Rate								0.50%
Base Rate | Revolving Credit Facility | Maximum
Debt Instrument
Debt Instrument, Basis Spread on Variable Rate								1%
Base Rate | Revolving Credit Facility | Median
Debt Instrument
Debt Instrument, Basis Spread on Variable Rate								0.75%
Federal Funds | Revolving Credit Facility
Debt Instrument
Debt Instrument, Basis Spread on Variable Rate								0.50%
Secured Overnight Financing Rate | Term Loan | Incremental Term Loan
Debt Instrument
Debt Instrument, Basis Spread on Variable Rate								1.50%
Secured Overnight Financing Rate | Term Loan | Second Incremental Term Loan
Debt Instrument
Debt Instrument, Basis Spread on Variable Rate								1.50%
One-Month adjusted term SOFR | Revolving Credit Facility
Debt Instrument
Debt Instrument, Basis Spread on Variable Rate								1%
Adjusted term SOFR | Revolving Credit Facility | Minimum
Debt Instrument
Debt Instrument, Basis Spread on Variable Rate								1.50%
Adjusted term SOFR | Revolving Credit Facility | Maximum
Debt Instrument
Debt Instrument, Basis Spread on Variable Rate								2%
Adjusted term SOFR | Revolving Credit Facility | Median
Debt Instrument
Debt Instrument, Basis Spread on Variable Rate								1.75%
BellRing Brands, LLC | 2020 Bridge Loan
Debt Instrument
Loans Payable to Bank														$ 1,225,000,000
BellRing | 2020 Bridge Loan
Debt Instrument
Interest Costs Incurred										2,200,000
Loss on extinguishment of debt, net
Debt Instrument
Premium and Debt Extinguishment Costs Paid									74,300,000	49,800,000
Write off of Deferred Debt Issuance Cost								$ 12,200,000	18,900,000	19,300,000
Write-off of Unamortized Debt Discount/(Premium)								(15,300,000)	0	0
Payment (Proceeds) for debt discounts and premiums								(73,700,000)
Loss on extinguishment of debt, net | Noncash
Debt Instrument
Premium and Debt Extinguishment Costs Paid								0		0
Write off of Deferred Debt Issuance Cost								4,200,000		3,800,000
Write-off of Unamortized Debt Discount/(Premium)								0		0
Loss on extinguishment of debt, net | Revolving Credit Facility
Debt Instrument
Premium and Debt Extinguishment Costs Paid										0
Write off of Deferred Debt Issuance Cost										0
Write-off of Unamortized Debt Discount/(Premium)										0
Loss on extinguishment of debt, net | Credit Agreement
Debt Instrument
Premium and Debt Extinguishment Costs Paid										0
Write off of Deferred Debt Issuance Cost										800,000
Write-off of Unamortized Debt Discount/(Premium)										0
Loss on extinguishment of debt, net | 2020 Bridge Loan | Noncash
Debt Instrument
Premium and Debt Extinguishment Costs Paid										0
Write off of Deferred Debt Issuance Cost										3,800,000
Write-off of Unamortized Debt Discount/(Premium)										0
Loss on extinguishment of debt, net | Term Loan
Debt Instrument
Premium and Debt Extinguishment Costs Paid										0
Write off of Deferred Debt Issuance Cost										9,100,000
Write-off of Unamortized Debt Discount/(Premium)										0
Loss on extinguishment of debt, net | Term Loan | Incremental Term Loan | Noncash
Debt Instrument
Premium and Debt Extinguishment Costs Paid								0
Write off of Deferred Debt Issuance Cost								3,500,000
Write-off of Unamortized Debt Discount/(Premium)								0
Loss on extinguishment of debt, net | Term Loan | Second Incremental Term Loan
Debt Instrument
Write off of Deferred Debt Issuance Cost								0
Write-off of Unamortized Debt Discount/(Premium)								0
Payment (Proceeds) for debt discounts and premiums								0
Loss on extinguishment of debt, net | Term Loan | Second Incremental Term Loan | Noncash
Debt Instrument
Premium and Debt Extinguishment Costs Paid								0
Write off of Deferred Debt Issuance Cost								700,000
Write-off of Unamortized Debt Discount/(Premium)								0
Loss on extinguishment of debt, net | Municipal Bonds
Debt Instrument
Premium and Debt Extinguishment Costs Paid									0	0
Write off of Deferred Debt Issuance Cost								0	0	0
Write-off of Unamortized Debt Discount/(Premium)								0	0	0
Payment (Proceeds) for debt discounts and premiums								0
Loss on extinguishment of debt, net | Senior Notes | 5.50% Senior Notes Maturing in December 2029
Debt Instrument
Write off of Deferred Debt Issuance Cost								100,000
Write-off of Unamortized Debt Discount/(Premium)								(200,000)
Payment (Proceeds) for debt discounts and premiums								(1,200,000)
Loss on extinguishment of debt, net | Senior Notes | 5.50% Senior Notes maturing March 2025
Debt Instrument
Premium and Debt Extinguishment Costs Paid										41,300,000
Write off of Deferred Debt Issuance Cost										8,700,000
Write-off of Unamortized Debt Discount/(Premium)										0
Loss on extinguishment of debt, net | Senior Notes | 5.75% Senior Notes Maturing March 2027
Debt Instrument
Write off of Deferred Debt Issuance Cost								5,000,000
Write-off of Unamortized Debt Discount/(Premium)								(13,300,000)
Payment (Proceeds) for debt discounts and premiums								24,100,000
Loss on extinguishment of debt, net | Senior Notes | 8.00% Senior Notes Maturing in July 2025
Debt Instrument
Premium and Debt Extinguishment Costs Paid										8,500,000
Write off of Deferred Debt Issuance Cost										700,000
Write-off of Unamortized Debt Discount/(Premium)										$ 0
Loss on extinguishment of debt, net | Senior Notes | 5.00% Senior Notes Maturing in August 2026
Debt Instrument
Premium and Debt Extinguishment Costs Paid									74,300,000
Write off of Deferred Debt Issuance Cost									18,900,000
Write-off of Unamortized Debt Discount/(Premium)									$ 0
Loss on extinguishment of debt, net | Senior Notes | 4.625% Senior Notes Maturing in April 2030
Debt Instrument
Write off of Deferred Debt Issuance Cost								1,100,000
Write-off of Unamortized Debt Discount/(Premium)								(1,800,000)
Payment (Proceeds) for debt discounts and premiums								(21,900,000)
Loss on extinguishment of debt, net | Senior Notes | 4.50% Senior Notes Maturing in September 2031
Debt Instrument
Write off of Deferred Debt Issuance Cost								6,000,000
Write-off of Unamortized Debt Discount/(Premium)								0
Payment (Proceeds) for debt discounts and premiums								$ (74,700,000)

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Millions		12 Months Ended
	Dec. 08, 2016 USD ($)	Sep. 30, 2022 USD ($) defendant plaintiff_group	Sep. 30, 2021 USD ($)
Bob Evans Farms
Loss Contingencies [Line Items]
Lease Guarantee, Number of Properties		130	143
Current annual rent of guaranteed leases		$ 12.9
Lease Guarantee, Interest rate increase		1.50%
Lease Guarantee, Remaining Lease Term		15 years
Michael Foods
Loss Contingencies [Line Items]
Loss Contingency, Pending Claims, Number		22
Loss Contingency, Pending Claims, Other Defendants | defendant		20
Loss Contingency, Pending Claims, Number of Plaintiff Groups | plaintiff_group		3
Litigation Settlement	$ 75
Accrued legal settlements, current			$ 3.5
Selling, general and administrative expenses | Michael Foods
Loss Contingencies [Line Items]
Litigation Settlement, Expense		$ 13.8

Pension and Other Postretirem_3

Pension and Other Postretirement Benefits - Change in Projected Benefit Obligation, Fair Value of Plan Assets, and Net Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Amounts recognized in assets or liabilities [Abstract]
Other liabilities	$ (45.6)	$ (64.2)
UNITED STATES
Weighted-average assumptions used to determine benefit obligation [Abstract]
Discount rate	5.62%	2.89%
CANADA
Weighted-average assumptions used to determine benefit obligation [Abstract]
Discount rate	5.12%	3.45%
Rate of compensation increase	2.75%	2.75%
Pension Benefits | UNITED STATES
Weighted-average assumptions used to determine benefit obligation [Abstract]
Discount rate	5.65%	3.05%
Rate of compensation increase	3%	3%
Pension Benefits | North America
Change in benefit obligation [roll forward]
Benefit obligation at beginning of period	$ 133.3	$ 131.1
Service cost	4.3	3.9	$ 4.3
Interest cost	3.5	3.2	3.7
Plan participants' contributions	0.4	0.4
Prior service cost	0	0.5
Actuarial (gain) loss	(38.9)	(1.4)
Business Combinations	0	0.5
Benefits Paid	(5.9)	(5.8)
Currency translation	(1.2)	0.9
Benefit obligation at end of period	$ 95.5	$ 133.3	$ 131.1
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Change in fair value of plan assets [roll forward]
Fair value of plan assets at beginning of period	$ 136.6	$ 121.5
Actual return on plan assets	(27.1)	19.5
Employer contributions	0.4	0.2
Plan participants' contributions	0.4	0.4
Benefits Paid	(5.9)	(5.8)
Currency translation	(1.5)	0.8
Other	0	0
Fair value of plan assets at end of period	102.9	136.6	$ 121.5
Defined benefit plan, funded status of plan [Abstract]
Funded status	7.4	3.3
Amounts recognized in assets or liabilities [Abstract]
Other assets	7.7	3.8
Other liabilities	(0.3)	(0.5)
Net amount recognized	7.4	3.3
Amounts recognized in accumulated other comprehensive income or loss [Abstract]
Net actuarial (gain) loss	5	11.3
Prior service cost (credit)	0.6	0.7
Total	5.6	12
Weighted-average assumptions used to determine benefit obligation [Abstract]
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Accumulated Benefit Obligation	94.6	130.8
Pension Benefits | Other international
Change in benefit obligation [roll forward]
Benefit obligation at beginning of period	821.3	834.4
Service cost	0	0
Interest cost	15.7	15.2	14.7
Plan participants' contributions	0	0
Prior service cost	0	0
Actuarial (gain) loss	(251.6)	(32.7)
Business Combinations	0	0
Benefits Paid	(28.4)	(34.7)
Currency translation	(135.9)	39.1
Benefit obligation at end of period	$ 421.1	$ 821.3	$ 834.4
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Change in fair value of plan assets [roll forward]
Fair value of plan assets at beginning of period	$ 970.9	$ 993.2
Actual return on plan assets	(273)	(34.1)
Employer contributions	0	0
Plan participants' contributions	0	0
Benefits Paid	(28.4)	(34.7)
Currency translation	(162.1)	46.7
Other	(0.1)	(0.2)
Fair value of plan assets at end of period	507.3	970.9	$ 993.2
Defined benefit plan, funded status of plan [Abstract]
Funded status	86.2	149.6
Amounts recognized in assets or liabilities [Abstract]
Other assets	86.2	149.6
Other liabilities	0	0
Net amount recognized	86.2	149.6
Amounts recognized in accumulated other comprehensive income or loss [Abstract]
Net actuarial (gain) loss	40.2	(6)
Prior service cost (credit)	10.7	11.1
Total	$ 50.9	$ 5.1
Weighted-average assumptions used to determine benefit obligation [Abstract]
Discount rate	5.15%	2.05%
Rate of compensation increase	3.85%	3.45%
Pension Benefits | CANADA
Weighted-average assumptions used to determine benefit obligation [Abstract]
Discount rate	5.12%	3.32%
Rate of compensation increase	2.75%	2.75%
Pension Benefits | Other International
Weighted-average assumptions used to determine benefit obligation [Abstract]
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Accumulated Benefit Obligation	$ 418.9	$ 817.8
Other Benefits | North America
Change in benefit obligation [roll forward]
Benefit obligation at beginning of period	66.5	70.7
Service cost	0.5	0.5	0.6
Interest cost	1.5	1.5	1.9
Actuarial (gain) loss	(17.4)	(4.3)
Benefits Paid	(2.3)	(2.4)
Currency translation	(0.5)	0.5
Benefit obligation at end of period	$ 48.3	$ 66.5	$ 70.7
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Change in fair value of plan assets [roll forward]
Fair value of plan assets at beginning of period	$ 0
Employer contributions	2.3	$ 2.4
Benefits Paid	(2.3)	(2.4)
Fair value of plan assets at end of period	0	0
Defined benefit plan, funded status of plan [Abstract]
Funded status	(48.3)	(66.5)
Amounts recognized in assets or liabilities [Abstract]
Other current liabilities	(3)	(2.8)
Other liabilities	(45.3)	(63.7)
Net amount recognized	(48.3)	(66.5)
Amounts recognized in accumulated other comprehensive income or loss [Abstract]
Net actuarial (gain) loss	(9.2)	8.9
Prior service cost (credit)	(5.4)	(10)
Total	$ (14.6)	$ (1.1)

Pension and Other Postretirem_4

Pension and Other Postretirement Benefits - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Changes in plan assets and benefit obligation recognized in other comprehensive income or loss [Abstract]
Net (gain) loss	$ 24	$ 8.1	$ 36.8
Pension Benefits | UNITED STATES
Weighted-average assumptions used to determine net benefit cost [Abstract]
Discount rate	3.05%	3.01%	3.32%
Rate of compensation increase	3%	3%	3%
Expected return on plan assets	5.75%	5.40%	5.53%
Pension Benefits | Other international
Components of net periodic benefit cost [Abstract]
Service cost	$ 0	$ 0
Interest cost	15.7	15.2	$ 14.7
Expected return on plan assets	(24.8)	(24.9)	(24.6)
Recognized prior service cost	0.4	0.5	0
Net periodic benefit cost	$ (8.7)	$ (9.2)	$ (9.9)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Expected Return (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Amortization of Prior Service Cost (Credit), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Weighted-average assumptions used to determine net benefit cost [Abstract]
Discount rate	2.05%	1.73%	1.84%
Rate of compensation increase	3.45%	2.65%	2.55%
Expected return on plan assets	2.73%	2.38%	2.53%
Changes in plan assets and benefit obligation recognized in other comprehensive income or loss [Abstract]
Net (gain) loss	$ 46.2	$ 26.4	$ 14.2
Prior Service Cost	0	0	11.4
Recognized prior service cost	(0.4)	(0.5)	0
Total recognized in other comprehensive income or loss (before tax effects)	45.8	25.9	25.6
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	0
Pension Benefits | North America
Components of net periodic benefit cost [Abstract]
Service cost	4.3	3.9	4.3
Interest cost	3.5	3.2	3.7
Expected return on plan assets	(7)	(6.4)	(6.4)
Recognized net actuarial loss	1.6	2.4	1.8
Recognized prior service cost	0.1	0.1	0.1
Net periodic benefit cost	$ 2.5	$ 3.2	$ 3.5
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Expected Return (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Amortization of Prior Service Cost (Credit), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Changes in plan assets and benefit obligation recognized in other comprehensive income or loss [Abstract]
Net (gain) loss	$ (4.7)	$ (14.5)	$ 6.6
Recognized loss	(1.6)	(2.4)	(1.8)
Prior Service Cost	0	0.5	0
Recognized prior service cost	(0.1)	(0.1)	(0.1)
Total recognized in other comprehensive income or loss (before tax effects)	(6.4)	$ (16.5)	$ 4.7
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 0.3
Pension Benefits | CANADA
Weighted-average assumptions used to determine net benefit cost [Abstract]
Discount rate	3.32%	2.71%	2.84%
Rate of compensation increase	2.75%	2.75%	2.75%
Expected return on plan assets	5.25%	5.25%	5.75%
Other Benefits | UNITED STATES
Weighted-average assumptions used to determine net benefit cost [Abstract]
Discount rate	2.89%	2.79%	3.20%
Other Benefits | North America
Components of net periodic benefit cost [Abstract]
Service cost	$ 0.5	$ 0.5	$ 0.6
Interest cost	1.5	1.5	1.9
Recognized net actuarial loss	0.6	1.1	0.6
Recognized prior service cost	(4.6)	(4.7)	(4.7)
Net periodic benefit cost	$ (2)	$ (1.6)	$ (1.6)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Amortization of Prior Service Cost (Credit), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Changes in plan assets and benefit obligation recognized in other comprehensive income or loss [Abstract]
Net (gain) loss	$ (17.5)	$ (4.3)	$ 4.6
Recognized loss	(0.6)	(1.1)	(0.6)
Recognized prior service cost	4.6	4.7	4.7
Total recognized in other comprehensive income or loss (before tax effects)	$ (13.5)	$ (0.7)	$ 8.7
Other Benefits | CANADA
Weighted-average assumptions used to determine net benefit cost [Abstract]
Discount rate	3.45%	2.78%	2.86%
Rate of compensation increase	2.75%	2.75%	2.75%

Pension and Other Postretirem_5

Pension and Other Postretirement Benefits - Pension Plan Assets Measured at Fair Value on a Recurring Basis (Details) - Pension Benefits - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Other international
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Actual allocations, index funds	20.20%	31.30%
Pension plan's assets at fair value	$ 507.3	$ 970.9	$ 993.2
Defined Benefit Plan, Fair Value of Plan Assets not Measured at NAV	409.8	873.5
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	97.5	97.4
Other international | Level 1
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	409.8	873.5
Defined Benefit Plan, Fair Value of Plan Assets not Measured at NAV	409.8	873.5
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	0	0
Other international | Level 2
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	0	0
Defined Benefit Plan, Fair Value of Plan Assets not Measured at NAV	0	0
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	$ 0	$ 0
Other international | Fixed Income Funds and Bonds
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	71.70%
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	78.80%	72.60%
Other international | Fixed Income Funds and Bonds | Level 1
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	$ 321.3	$ 649.3
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	0	0
Other international | Fixed Income Funds and Bonds | Level 2
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	0	0
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	0	0
Other international | Fixed Income Funds and Bonds | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	321.3	649.3
Other international | Fixed Income Funds and Bonds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	$ 78.5	$ 56.1
Other international | Liability Hedging Instruments
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	27.60%
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	18.70%	24.30%
Other international | Liability Hedging Instruments | Level 1
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	$ 77.9	$ 206.4
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	0	0
Other international | Liability Hedging Instruments | Level 2
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	0	0
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	0	0
Other international | Liability Hedging Instruments | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	77.9	206.4
Other international | Liability Hedging Instruments | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	$ 16.9	$ 29.3
Other international | Real assets
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	0.50%
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	0.40%	1%
Other international | Real assets | Level 1
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	$ 0	$ 0
Other international | Real assets | Level 2
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	0	0
Other international | Real assets | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	$ 2.1	$ 9.5
Other international | Cash and Cash Equivalents
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	0.20%
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	2.10%	2.10%
Other international | Cash and Cash Equivalents | Level 1
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	$ 10.6	$ 17.8
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	0	0
Other international | Cash and Cash Equivalents | Level 2
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	0	0
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	0	0
Other international | Cash and Cash Equivalents | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	10.6	17.8
Other international | Cash and Cash Equivalents | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	$ 0	$ 2.5
North America
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Actual allocations, index funds	91.90%	97.80%
Pension plan's assets at fair value	$ 102.9	$ 136.6	$ 121.5
Defined Benefit Plan, Fair Value of Plan Assets not Measured at NAV	24.9	22.9
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	78	113.7
North America | Level 1
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	8.9	3.4
Defined Benefit Plan, Fair Value of Plan Assets not Measured at NAV	8.9	3.4
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	0	0
North America | Level 2
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	16	19.5
Defined Benefit Plan, Fair Value of Plan Assets not Measured at NAV	16	19.5
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	$ 0	$ 0
North America | Equities
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	58.10%
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	54.50%	61.40%
North America | Equities | Level 1
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	$ 0	$ 0
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	0	0
North America | Equities | Level 2
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	11	13.8
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	0	0
North America | Equities | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	11	13.8
North America | Equities | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	$ 45.1	$ 70.1
North America | Fixed Income Funds and Bonds
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	37.80%
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	33.90%	34.40%
North America | Fixed Income Funds and Bonds | Level 1
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	$ 0	$ 0
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	0	0
North America | Fixed Income Funds and Bonds | Level 2
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	5	5.7
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	0	0
North America | Fixed Income Funds and Bonds | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	5	5.7
North America | Fixed Income Funds and Bonds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	$ 29.9	$ 41.2
North America | Real assets
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	3.40%
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	2.90%	1.80%
North America | Real assets | Level 1
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	$ 0	$ 0
North America | Real assets | Level 2
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	0	0
North America | Real assets | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Defined Benefit Plan, Plan Assets, Amount Measured at Net Asset Value	$ 3	$ 2.4
North America | Cash and Cash Equivalents
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	0.70%
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	8.70%	2.40%
North America | Cash and Cash Equivalents | Level 1
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	$ 8.9	$ 3.4
North America | Cash and Cash Equivalents | Level 2
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	0	0
North America | Cash and Cash Equivalents | Fair Value, Inputs, Level 1, 2 and 3
Defined Benefit Plan, Actual Plan Asset Allocation [Abstract]
Pension plan's assets at fair value	$ 8.9	$ 3.4

Pension and Other Postretirem_6

Pension and Other Postretirement Benefits - Effect of One-Percentage Point Change in Assumed Health Care Cost Trend Rates (Details) - Other Benefits	Sep. 30, 2022	Sep. 30, 2021
Defined Benefit Plan Disclosure
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate	5%	5%
Participants Over and Under 65
Defined Benefit Plan Disclosure
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year	6.30%	5.90%
CANADA | Participants Over and Under 65
Defined Benefit Plan Disclosure
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year	4.50%	4.50%

Pension and Other Postretirem_7

Pension and Other Postretirement Benefits - Expected Future Benefit Payments and Related Federal Subsidy Receipts (Details) $ in Millions	Sep. 30, 2022 USD ($)
Pension Benefits
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
Year 1	$ 24.3
Year 2	24.8
Year 3	25.9
Year 4	27.1
Year 5	28.2
Year 6 and thereafter	156.2
Other Benefits
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
Year 1	3.2
Year 2	3.4
Year 3	3.4
Year 4	3.4
Year 5	3.5
Year 6 and thereafter	17.9
Disclosure of Expected Gross Prescription Drug Subsidy Receipts [Abstract]
Year 1	0.1
Year 2	0.1
Year 3	0.1
Year 4	0.2
Year 5	0.2
Years 6 and thereafter	$ 1.1

Pension and Other Postretirem_8

Pension and Other Postretirement Benefits - Defined contribution plan expense (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Retirement Benefits [Abstract]
401K Matching Contributions	$ 19.6	$ 19.9	$ 18.4

Stock-Based Compensation Plan_2

Stock-Based Compensation Plans Narrative (Details) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020	Jan. 27, 2022
Share-based Payment Award [Line Items]
Matching contribution on Director Deferred Compensation	33.30%
Post Long-Term Incentive Plans
Share-based Payment Award [Line Items]
Share-based Compensation Arrangement , Maximum Award Vesting Period	10 years
Stock Based Compensation Awards [Abstract]
Stock-based Compensation Expense	$ 66.4	$ 49.7	$ 43.2
Recognized deferred tax beneft	9.1	$ 5.8	$ 6
Compensation cost related to nonvested awards not yet recognized	$ 78.5
Awards not yet recognized. weighted average period to be recognized	1 year 3 months 18 days
Restricted Stock Awards [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	1.8
2021 Long-Term Incentive Plan
Restricted Stock Awards [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized				2.4

Stock-Based Compensation Plan_3

Stock-Based Compensation Plans - Stock Appreciation Rights Award Activity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Post Cash Settled
Stock Appreciation Rights
Total Share-based Liabilities Paid	$ 1.1	$ 1.1	$ 0.9
Granted	0
Impact of Spin-off	14,193
Nonvestsed restricted stock awards	29,063	29,400
Post Stock Settled
Stock Appreciation Rights
Outstanding	81,554	95,000
Granted	0
Impact of Spin-off	41,038
Exercised	(54,484)
Forfeited	0
Expired	0
Vested And Expected To Vest	81,554
Exercisable	81,554
Outstanding, Weighted Average Exercise Price	$ 33.42	$ 46.59
Granted, Weighted Average Exercise Price
Impact of Spin-off, Weighted Average Price	33.62
Exercised, Weighted Average Exercise Price	31.22
Forfeited, Weighted Average Exercise Price
Expired, Weighted Average Exercise Price
Vested And Expected To Vest, Weighted Average Exercise Price	33.42
Exercisable, Weighted Average Exercise Price	$ 33.42
Outstanding, Weighted Average Remaining Contractual Term	1 year 7 months 20 days
Vested And Expected To Vest, Outstanding, Weighted Average Remaining Contractual Term	1 year 7 months 20 days
Exercisable, Weighted Average Remaining Contractual Term	1 year 7 months 20 days
Outstanding, Intrinsic Value	$ 4
Vested And Expected To Vest, Outstanding, Aggregate Intrinsic Value	4
Exercisable, Aggregate Intrinsic Value	4
Exercised, Total Intrinsic Value	$ 3	$ 3.2	$ 0.1

Stock-Based Compensation Plan_4

Stock-Based Compensation Plans - Stock Option award activity (Details) - Post Stock Options - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Share-based Payment Award [Line Items]
Outstanding	1,011,315	889,096
Granted	0
Impact of Spin-off	353,559
Exercised	(231,340)
Forfeited	0
Expired	0
Vested and Expected to Vest	1,011,315
Exercisable	996,235
Outstanding, Weighted Average Exercise Price	$ 48.75	$ 65.67
Granted, Weighted Average Exercise Price	0
Impact of Spin-off, Weighted Average Price	48.89
Exercised, Weighted Average Exercise Price	39.28
Forfeited, Weighted Average Exercise Price	0
Expired, Weighted Average Exercise Price	0
Vested and Expected to Vest, Weighted Average Exercise Price	48.75
Exercisable, Weighted Average Exercise Price	$ 48.40
Outstanding, Weighted Average Remaining Contractual Term	4 years 4 months 2 days
Vested and Expected to Vest, Weighted Average Remaining Contractual Term	4 years 4 months 2 days
Exercisable, Weighted Average Remaining Contractual Term	4 years 3 months 18 days
Outstanding, Intrinsic Value	$ 33.5
Vested and Expected to Vest, Aggregate Intrinsic Value	33.5
Exercisable, Intrinsic Value	33.4
Expected Term			6 years 6 months
Expected Volatility Rate			29.20%
Risk Free Interest Rate			1.80%
Expected Dividend Rate			0%
Fair value per option			$ 35.32
Exercised, Total Intrinsic Value	14.1	$ 46.4	$ 5.5
Proceeds from Stock Options Exercised	$ 4.9	$ 7.6	$ 3.9

Stock-Based Compensation Plan_5

Stock-Based Compensation Plans - Restricted Stock Units (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Post Stock Settled
Share-based Payment Award [Line Items]
Nonvestsed restricted stock awards	1,348,806	822,112
Granted	432,538
Impact of Spin-off	520,090
Vested	(361,026)
Forfeited	(64,908)
Grant date value per share	$ 68.38	$ 97.23	$ 89.14
Granted, Weighted Average Exercise Price	102.58
Vested, Weighted Average Exercise Price	91.68
Forfeited, Weighted Average Exercise Price	$ 81.63
Fair value of restricted stock awards vested	$ 35.1	$ 49.8	$ 42.1
Post Cash Settled
Share-based Payment Award [Line Items]
Grant date price of restricted stock units valued at greater of current stock price or grant price	$ 34.68
Nonvestsed restricted stock awards	29,063	29,400
Granted	0
Impact of Spin-off	14,193
Vested	(14,530)
Forfeited	0
Grant date value per share	$ 34.68	$ 51.43
Granted, Weighted Average Exercise Price	0
Vested, Weighted Average Exercise Price	34.68
Forfeited, Weighted Average Exercise Price	$ 0
Total Share-based Liabilities Paid	$ 1.1	$ 1.1	$ 0.9

Stock-Based Compensation Plan_6

Stock-Based Compensation Plans Performance Restricted Stock Units (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Post Stock Settled
Share-based Payment Award [Line Items]
Granted, Weighted Average Exercise Price	$ 163.63	$ 152.58	$ 138.10
Fair value of restricted stock awards vested	$ 6.6	$ 3.9
Minimum
Share-based Payment Award [Line Items]
Total Award Range	0%
Maximum
Share-based Payment Award [Line Items]
Total Award Range	260%
Earnings-Based Restricted Stock Units
Share-based Payment Award [Line Items]
Expected Term	3 years	3 years	3 years
Expected Volatility Rate	27.70%	28.30%	22.20%
Risk Free Interest Rate	0.90%	0.20%	1.60%
Earnings-Based Restricted Stock Units | Post Stock Settled
Share-based Payment Award [Line Items]
Nonvestsed restricted stock awards	272,427	7,526
Granted	195,533
Impact of Spin-off	96,177
Adjustment for performance achievement	(12,588)
Vested	0
Forfeited	(14,221)
Grant date value per share	$ 70.46	$ 98.33
Granted, Weighted Average Exercise Price	104.74
Vested, Weighted Average Exercise Price	0
Forfeited, Weighted Average Exercise Price	$ 78.27
Market-based performance shares | Post Stock Settled
Share-based Payment Award [Line Items]
Nonvestsed restricted stock awards	374,402	285,335
Granted	108,922
Impact of Spin-off	62,114
Adjustment for performance achievement	(19,508)
Vested	(61,940)
Forfeited	(521)
Grant date value per share	$ 106.10	$ 142.61
Granted, Weighted Average Exercise Price	163.63
Vested, Weighted Average Exercise Price	122.34
Forfeited, Weighted Average Exercise Price	$ 110.35

Shareholders' Equity (Details)

Shareholders' Equity (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		5 Months Ended	7 Months Ended	12 Months Ended
	Aug. 12, 2022	Mar. 10, 2022	Sep. 30, 2022	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Class of Stock [Line Items]
Cash paid for share repurchase contracts				$ 0	$ 0	$ (46.4)
Cash received from share repurchase contracts				$ 0	$ 47.5	$ 0
Common Stock
Class of Stock [Line Items]
Treasury Stock, Shares, Acquired	1.1			4.9	4	6.1
Treasury Stock Acquired, Average Cost Per Share				$ 90.04	$ 98.39	$ 97.67
Purchases of treasury stock				$ 439	$ 393.7	$ 587.8
Payments for accrued repurchases of common stock					$ 4
Common Stock
Class of Stock [Line Items]
Treasury Stock Acquired, Average Cost Per Share		$ 103.81	$ 81.54

Segments (Details)

Segments (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Net Sales	$ 5,851.2	$ 4,980.7	$ 4,711
Operating Profit	415.6	487.7	536.5
Interest expense, net	317.8	332.6	333.9
(Gain) loss on extinguishment of debt, net	(72.6)	93.2	72.9
(Income) expense on swaps, net	(268)	(122.8)	187.1
Gain on investment in BellRing	(437.1)	0	0
Earnings (loss) before income taxes and equity method loss	895.3	214	(45.9)
Property, Plant and Equipment, Additions	274.8	190.9	232.5
Depreciation and amortization	380.2	366.5	$ 345
Assets	11,308	12,414.7
Disposal Group, Including Discontinued Operation, Assets	0	694.1
Noncash
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Additions	19.5
Continuing Operations
Segment Reporting Information [Line Items]
Assets	$ 11,308	$ 11,720.6
Customer Concentration Risk | Revenue Benchmark | Walmart
Segment Reporting Information [Line Items]
Entity-Wide Revenue, Major Customer, Percentage	14.40%	15.90%	18.70%
Non-US
Segment Reporting Information [Line Items]
Sales to Foreign Countries as a Percentage of Total Net Sales	12.50%	14.30%	14.50%
Disclosure on Geographic Areas, Long-Lived Assets in Foreign Countries	$ 253.6	$ 300.2
Canada as a percentage of Non-US
Segment Reporting Information [Line Items]
Sales to Foreign Countries as a Percentage of Total Net Sales	52.90%	54.60%	53.60%
Operating Segments
Segment Reporting Information [Line Items]
Net Sales	$ 5,851.2	$ 4,980.7	$ 4,711
Operating Profit	632.2	569.6	657
Depreciation and amortization	376.5	362.5	341
Operating Segments | Post Consumer Brands Segment
Segment Reporting Information [Line Items]
Net Sales	2,242.7	1,915.3	1,949.1
Operating Profit	314.6	316.6	393.5
Property, Plant and Equipment, Additions	91.2	81.2	67.4
Depreciation and amortization	133.1	122	112.4
Assets	3,529.1	3,467.8
Operating Segments | Weetabix Segment
Segment Reporting Information [Line Items]
Net Sales	477.3	477.5	440.4
Operating Profit	109.5	115.4	112.3
Property, Plant and Equipment, Additions	26.7	19.6	24.6
Depreciation and amortization	37.5	39	35.9
Assets	1,591.3	1,930.4
Operating Segments | Foodservice and Refrigerated Retail
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Additions	136.1	89.7	139.5
Assets	5,022.7	5,074.2
Operating Segments | Foodservice Segment
Segment Reporting Information [Line Items]
Net Sales	2,095	1,615.6	1,361.8
Operating Profit	151	61.7	25.6
Depreciation and amortization	127.5	126	119.6
Operating Segments | Refrigerated Retail Segment
Segment Reporting Information [Line Items]
Net Sales	1,036.6	974.5	961.2
Operating Profit	57.1	75.9	125.6
Depreciation and amortization	78.4	75.5	73.1
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Other Expenses	196.8	52.6	109
Property, Plant and Equipment, Additions	20.8	0.4	1
Depreciation and amortization	3.7	4	4
Assets	1,164.9	1,248.2
Intersegment Eliminations
Segment Reporting Information [Line Items]
Net Sales	(0.4)	(2.2)	(1.5)
Cereal | Operating Segments
Segment Reporting Information [Line Items]
Net Sales	2,595	2,333.3	2,388.7
Nut butters | Operating Segments
Segment Reporting Information [Line Items]
Net Sales	111.7	58.7	0
Eggs and egg products | Operating Segments
Segment Reporting Information [Line Items]
Net Sales	2,026.1	1,556.1	1,307.8
Side dishes (including potato products) | Operating Segments
Segment Reporting Information [Line Items]
Net Sales	652.4	575	536.6
Cheese and dairy | Operating Segments
Segment Reporting Information [Line Items]
Net Sales	214.3	223	253.2
Sausage | Operating Segments
Segment Reporting Information [Line Items]
Net Sales	171.2	165.9	168.1
Protein-based products | Operating Segments
Segment Reporting Information [Line Items]
Net Sales	12.9	0	0
Other | Operating Segments
Segment Reporting Information [Line Items]
Net Sales	68.5	70.9	58.1
Product Eliminations
Segment Reporting Information [Line Items]
Net Sales	$ (0.9)	$ (2.2)	$ (1.5)