Business Combinations (Details) - USD ($) $ in Millions						3 Months Ended			9 Months Ended		12 Months Ended
	Jun. 01, 2021	May 27, 2021	Feb. 01, 2021	Jan. 25, 2021	Jul. 01, 2020	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Sep. 30, 2020
Business Acquisition
Net Sales						$ 1,589.8		$ 1,336.4	$ 4,531.1	$ 4,287.4
Operating Profit (Loss)						206.5		$ 172.1	517.9	$ 521.6
Goodwill						4,597.1			4,597.1		$ 4,438.6
Foodservice
Business Acquisition
Goodwill						1,355.0			1,355.0		1,335.6
Refrigerated Retail
Business Acquisition
Goodwill						762.7			762.7		744.9
PL RTE Cereal Business
Business Acquisition
Payments to Acquire Businesses, Base Purchase Price	$ 85.0
Payment at closing	$ 88.0
Net Sales						16.6			16.6
Operating Profit (Loss)						(2.0)			(2.0)
Receivables						0.0			0.0
Inventories						36.0			36.0
Prepaid expenses and other current assets						0.0			0.0
Property						69.4			69.4
Goodwill						0.0			0.0
Other intangible assets						0.0			0.0
Deferred tax asset						0.0			0.0
Other assets						0.2			0.2
Accounts payable						0.0			0.0
Other current liabilities						0.0			0.0
Deferred tax liability						(4.2)			(4.2)
Other liabilities						(0.7)			(0.7)
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net						100.7			100.7
Business Combination, Bargain Purchase, Gain Recognized, Amount							$ 12.7		12.7
Egg Beaters
Business Acquisition
Payments to Acquire Businesses, Base Purchase Price		$ 50.0
Payment at closing		$ 50.6
Net Sales						3.2			3.2
Operating Profit (Loss)						0.0			0.0
Receivables						0.0			0.0
Inventories						3.1			3.1
Prepaid expenses and other current assets						0.0			0.0
Property						7.0			7.0
Goodwill						17.8			17.8
Other intangible assets						35.0			35.0
Deferred tax asset						0.0			0.0
Other assets						0.0			0.0
Accounts payable						(10.1)			(10.1)
Other current liabilities						0.0			0.0
Deferred tax liability						(2.1)			(2.1)
Other liabilities						0.0			0.0
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net						50.7			50.7
Egg Beaters | Other Current Liabilities
Business Acquisition
Business Combination, Working Capital Payable						0.1			$ 0.1
Egg Beaters | Customer Relationships
Business Acquisition
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life									15 years
Other intangible assets						26.0			$ 26.0
Egg Beaters | Trademarks and Brands
Business Acquisition
Other intangible assets						9.0			9.0
Almark Foods
Business Acquisition
Payments to Acquire Businesses, Base Purchase Price			$ 52.0
Payment at closing			$ 51.3
Net Sales						24.0			38.4
Operating Profit (Loss)						(2.7)			(2.6)
Receivables						5.9			5.9
Inventories						4.0			4.0
Prepaid expenses and other current assets						0.1			0.1
Property						9.8			9.8
Goodwill						19.4			19.4
Other intangible assets						19.5			19.5
Deferred tax asset						1.3			1.3
Other assets						27.7			27.7
Accounts payable						(6.4)			(6.4)
Other current liabilities						(1.2)			(1.2)
Deferred tax liability						0.0			0.0
Other liabilities						(31.8)			(31.8)
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net						48.3			48.3
Almark Foods | Receivables, net
Business Acquisition
Business Combination, Working Capital Receivable						3.0			$ 3.0
Almark Foods | Customer Relationships
Business Acquisition
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life									10 years
Other intangible assets						19.5			$ 19.5
Peter Pan
Business Acquisition
Payments to Acquire Businesses, Base Purchase Price				$ 102.0
Payment at closing				$ 103.4
Net Sales						21.8			39.2
Operating Profit (Loss)						2.1			5.6
Working capital settlement received									2.0
Receivables						0.0			0.0
Inventories						4.6			4.6
Prepaid expenses and other current assets						0.0			0.0
Property						0.0			0.0
Goodwill						55.1			55.1
Other intangible assets						67.0			67.0
Deferred tax asset						0.0			0.0
Other assets						0.0			0.0
Accounts payable						(11.7)			(11.7)
Other current liabilities						0.0			0.0
Deferred tax liability						(13.6)			(13.6)
Other liabilities						0.0			0.0
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net						101.4			$ 101.4
Peter Pan | Customer Relationships
Business Acquisition
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life									20 years
Other intangible assets						12.0			$ 12.0
Peter Pan | Trademarks and Brands
Business Acquisition
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life									20 years
Other intangible assets						$ 55.0			$ 55.0
Henningsen Foods
Business Acquisition
Payments to Acquire Businesses, Base Purchase Price					$ 20.0
Payment at closing					$ 22.7
Working capital settlement received									1.0
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net											32.6
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents											2.8
Business Combination, Bargain Purchase, Gain Recognized, Amount											11.7
Business Combination, Working Capital Receivable											$ 1.8
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Inventory and Deferred Income Taxes									0.7
Business Combination, Adjustment to Bargain Purchase, Gain (Loss)									$ (0.1)