Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
	May 30, 2021	May 31, 2020	May 26, 2019	May 27, 2018	Jul. 01, 2011
Noncontrolling Interest [Line Items]
Recognized tax windfall benefits related to the exercise of stock-based awards	$ 12.4	$ 27.3	$ 24.5
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Equity	(9,773.2)	(8,349.5)	(7,367.7)	$ (6,492.4)
Benefit plan non-service income	(132.9)	(112.8)	(87.9)
Retained earnings	(17,069.8)	(15,982.1)
Deferred income taxes	(2,118.4)	(1,947.1)
Other current liabilities	1,787.2	1,633.3
Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Equity	$ (17,069.8)	(15,982.1)	(14,996.7)	$ (14,459.6)
Building [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment Useful Life	40 years
Yoplait SAS [Member]
Noncontrolling Interest [Line Items]
Ownership interest percentage in consolidated subsidiary	51.00%
Yoplait SAS [Member] | Redeemable Interest [Member]
Noncontrolling Interest [Line Items]
Redeemable interest percentage	49.00%				49.00%
Redeemable interest terms	Sodiaal has the ability to put all or a portion of its redeemable interest to us at fair value once per year, up to three times before December 2024.
Minimum [Member]
Property, Plant and Equipment [Line Items]
Finite-Lived Intangible Assets Useful Life	4 years
Minimum [Member] | Equipment, Furniture and Software [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment Useful Life	3 years
Maximum [Member]
Property, Plant and Equipment [Line Items]
Finite-Lived Intangible Assets Useful Life	30 years
Maximum [Member] | Equipment, Furniture and Software [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment Useful Life	10 years
Accounting Standards Update 2017-07 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Operating Results			87.9
Benefit plan non-service income			87.9
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred income taxes			11.4
Other current liabilities			45.3
Accounting Standards Update 2014-09 [Member] | Retained Earnings [Member] | Cumulative Effect Period Of Adoption [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Equity	$ 0.0	0.0	33.9
Accounting Standards Update 2016-13 [Member] | Retained Earnings [Member] | Cumulative Effect Period Of Adoption [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Equity	$ 5.7	$ 0.0	$ 0.0