Business Combinations (Details) - USD ($)		3 Months Ended
	Jan. 12, 2018	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017	Oct. 01, 2018
Business Acquisition
Business Divestiture, Purchase Price Adjustment, Net Working Capital and Other Adjustments		$ 22,600,000
Gain on sale of business related to 8th Avenue Transactions		124,700,000		$ 0
Foreign currency losses reclassified from accumulated OCI		42,100,000		0
Goodwill		4,478,500,000	$ 4,499,600,000
Goodwill, Purchase Accounting Adjustments		(700,000)
Transaction-related expenses		$ 10,700,000		3,100,000
Bob Evans Farms
Business Acquisition
Business Acquisition, Share Price	$ 77.00
Shares for which merger consideration has been paid		2,500,000
Payments to Acquire Businesses, Net of Cash Acquired	$ 1,381,200,000
Shares not yet paid	4,350,000		3,300,000
Basis spread on amounts owed to appraisal rights holders		5.00%
Business Acquisition, Goodwill, Expected Tax Deductible Amount	$ 13,800,000
Cash and cash equivalents		$ 15,600,000	$ 15,600,000
Receivables		58,500,000	58,500,000
Inventories		27,100,000	27,100,000
Prepaid expenses and other current assets		34,300,000	34,300,000
Property		184,300,000	184,300,000
Goodwill		897,600,000	898,300,000
Other intangible assets		782,000,000	782,000,000
Other assets		400,000	400,000
Accounts payable		(18,200,000)	(18,200,000)
Other current liabilities		(58,500,000)	(58,500,000)
Deferred tax liability - long-term		(194,200,000)	(194,900,000)
Other liabilities		(5,300,000)	(5,300,000)
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net		1,723,600,000	1,723,600,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Inventory		0
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Property		0
Goodwill, Purchase Accounting Adjustments		(700,000)
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Other intangible assets		0
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Consideration Transferred		0
Bob Evans Farms | Cash and Cash Equivalents
Business Acquisition
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Assets		0
Bob Evans Farms | Accounts Receivable
Business Acquisition
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Assets		0
Bob Evans Farms | Prepaid Expenses and Other Current Assets
Business Acquisition
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Assets		0
Bob Evans Farms | Other Assets
Business Acquisition
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Assets		0
Bob Evans Farms | Accounts Payable
Business Acquisition
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Liabilities		0
Bob Evans Farms | Other Current Liabilities
Business Acquisition
Payments to be made subsequent to the closing of the acquisition		13,700,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Liabilities		0
Bob Evans Farms | Deferred tax liability - long term
Business Acquisition
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Liabilities		700,000
Bob Evans Farms | Other Liabilities
Business Acquisition
Payments to be made subsequent to the closing of the acquisition			267,000,000
Payments to appraisal rights holders, including interest		257,600,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Liabilities		0
Bob Evans Farms | Trademarks
Business Acquisition
Indefinite-Lived Intangible Assets Acquired	400,000,000
Bob Evans Farms | Customer Relationships
Business Acquisition
Definite-lived Intangible Assets Acquired	$ 376,000,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	18 years
Bob Evans Farms | Trademarks
Business Acquisition
Definite-lived Intangible Assets Acquired	$ 6,000,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	10 years
8th Avenue
Business Acquisition
Equity Method Investment, Ownership Percentage					60.50%
Transaction-related expenses		$ 9,100,000		$ 700,000
8th Avenue | Post Holdings, Inc.
Business Acquisition
Proceeds from independent capitalization of a subsidiary					$ 875,000,000
Equity Method Investment, Ownership Percentage					60.50%
Proceeds from Issuance of Preferred Stock					$ 250,000,000
8th Avenue | THL
Business Acquisition
Equity Method Investment, Ownership Percentage					39.50%
Preferred Stock, Shares Issued					2,500,000
Preferred Stock, Dividend Rate, Agreed upon Percentage					11.00%
Preferred Stock, Liquidation Preference, Value					$ 100.00
Bridge Loan | 8th Avenue
Business Acquisition
Proceeds from Issuance of Unsecured Debt			625,000,000
Bridge Loan | 8th Avenue | Post Holdings, Inc.
Business Acquisition
Proceeds from Issuance of Unsecured Debt			$ 625,000,000