Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
	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	$ 27.3	$ 24.5	$ 25.5
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Benefit plan non-service income	(112.8)	(87.9)	(89.4)
Deferred Income Tax Liabilities, Net	1,947.1	2,031.0
Other current liabilities	$ 1,633.3	1,367.8
Yoplait SAS [Member]
Noncontrolling Interest [Line Items]
Ownership interest percentage in consolidated subsidiary	51.00%
Building [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment Useful Life	40 years
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
Sodiaal International Redeemable Interest [Member] | Yoplait SAS [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.
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	89.4
Benefit plan non-service income		(87.9)	(89.4)
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets		(33.9)
Deferred Income Tax Liabilities, Net		(11.4)
Other current liabilities		$ 45.3
Accounting Standards Update 2018 02 {Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification from AOCI to retained earnings, stranded income tax effects resulting from the Tax Cuts and Jobs Act of 2017			$ 329.4