Consolidated Statements of Total Equity and Redeemable Interest - USD ($) shares in Millions, $ in Millions	Total	Redeemable Interest [Member]	Parent [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member] Cumulative Effect Period Of Adoption [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interests [Member]
Beginning Balance, Treasury Stock, Shares at May. 26, 2019								(152.7)
Stockholders' Equity, Number of Shares
Shares purchased, shares	(0.1)							(0.1)
Stock compensation plans								8.0
Ending Balance, Treasury Stock, Shares at May. 31, 2020								(144.8)
Ending Balance, Common Stock, Shares, Issued at May. 31, 2020	754.6
Beginning Balance, equity at May. 26, 2019	$ 7,367.7				$ 1,386.7	$ 14,996.7		$ (6,779.0)	$ (2,625.4)	$ 313.2
Beginning Balance, equity (Accounting Standards Update 2016-13 [Member]) at May. 26, 2019							$ 0.0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Shares issued, value				$ 75.5
Stock compensation plans					(12.1)			349.1
Unearned compensation related to stock unit awards					(85.7)
Earned compensation					92.8
Comprehensive income (loss)									(289.0)	10.3
Decrease (increase) in redemption value of redeemable interest		$ 33.1			(33.1)
Net earnings attributable to General Mills	2,181.2		$ 2,181.2			2,181.2
Shares purchased, value	(3.4)							(3.4)
Reclassification from Redeemable Interest										0.0
Reversal of Cumulative Redeemable Interest Value Adjustments					0.0					0.0
Divestiture										0.0
Acquisition of noncontrolling interest					0.0
Cash dividends declared ($2.04, $2.02 and $1.96 per share)						(1,195.8)
Distributions to redeemable interest holder		(40.0)								(32.5)
Reclassification to noncontrolling interest		0.0
Ending Balance, equity at May. 31, 2020	8,349.5				1,348.6	15,982.1		$ (6,433.3)	(2,914.4)	291.0
Ending Balance, equity (Accounting Standards Update 2016-13 [Member]) at May. 31, 2020							(5.7)
Beginning Balance, Redeemable Noncontrolling Interest, Equity, Other, Fair Value at May. 26, 2019		551.7
Redeemable Interest
Total comprehensive income (loss) attributable to redeemable interests		(0.2)
Decrease (increase) in redemption value of redeemable interest		33.1			(33.1)
Distributions to redeemable interest holder		(40.0)								(32.5)
Ending Balance, Redeemable Noncontrolling Interest, Equity, Other, Fair Value at May. 31, 2020		544.6
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Net earnings attributable to General Mills	$ 638.9
Ending Balance, equity (Accounting Standards Update 2016-13 [Member]) at Aug. 30, 2020							(5.7)
Beginning Balance, Common Stock, Shares, Issued at May. 31, 2020	754.6
Beginning Balance, Treasury Stock, Shares at May. 31, 2020								(144.8)
Stockholders' Equity, Number of Shares
Shares purchased, shares	(5.0)							(5.0)
Stock compensation plans								2.9
Ending Balance, Treasury Stock, Shares at May. 30, 2021	(146.9)							(146.9)
Ending Balance, Common Stock, Shares, Issued at May. 30, 2021	754.6
Beginning Balance, equity at May. 31, 2020	$ 8,349.5				1,348.6	15,982.1		$ (6,433.3)	(2,914.4)	291.0
Beginning Balance, equity (Accounting Standards Update 2016-13 [Member]) at May. 31, 2020							(5.7)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Shares issued, value				75.5
Stock compensation plans					6.2			123.5
Unearned compensation related to stock unit awards					(78.0)
Earned compensation					88.5
Comprehensive income (loss)									485.2	38.0
Decrease (increase) in redemption value of redeemable interest		(0.2)			0.2
Net earnings attributable to General Mills	2,339.8		2,339.8			2,339.8
Shares purchased, value	(301.4)							(301.4)
Reclassification from Redeemable Interest										0.0
Reversal of Cumulative Redeemable Interest Value Adjustments					0.0					0.0
Divestiture										0.0
Acquisition of noncontrolling interest					0.0
Cash dividends declared ($2.04, $2.02 and $1.96 per share)						(1,246.4)
Distributions to redeemable interest holder		(22.7)								(26.2)
Reclassification to noncontrolling interest		0.0
Ending Balance, equity at May. 30, 2021	9,773.2				1,365.5	17,069.8		$ (6,611.2)	(2,429.2)	302.8
Beginning Balance, Redeemable Noncontrolling Interest, Equity, Other, Fair Value at May. 31, 2020		544.6
Redeemable Interest
Total comprehensive income (loss) attributable to redeemable interests		83.2
Decrease (increase) in redemption value of redeemable interest		(0.2)			0.2
Distributions to redeemable interest holder		(22.7)								(26.2)
Ending Balance, Redeemable Noncontrolling Interest, Equity, Other, Fair Value at May. 30, 2021	$ 604.9	604.9
Stockholders' Equity, Number of Shares
Shares purchased, shares	(13.5)							(13.5)
Stock compensation plans								4.7
Ending Balance, Treasury Stock, Shares at May. 29, 2022	(155.7)							(155.7)
Ending Balance, Common Stock, Shares, Issued at May. 29, 2022	754.6
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Shares issued, value				$ 75.5
Stock compensation plans					17.9			$ 209.9
Unearned compensation related to stock unit awards					(92.2)
Earned compensation					104.5
Comprehensive income (loss)									458.7	(16.0)
Decrease (increase) in redemption value of redeemable interest		(14.1)			14.1
Net earnings attributable to General Mills	$ 2,707.3		$ 2,707.3			2,707.3
Shares purchased, value	(876.8)							(876.8)
Reclassification from Redeemable Interest										561.6
Reversal of Cumulative Redeemable Interest Value Adjustments					(207.4)					207.4
Divestiture										(680.4)
Acquisition of noncontrolling interest					(19.5)
Cash dividends declared ($2.04, $2.02 and $1.96 per share)						(1,244.5)
Distributions to redeemable interest holder		0.0								(129.8)
Reclassification to noncontrolling interest		(561.6)
Ending Balance, equity at May. 29, 2022	10,788.0				1,182.9	$ 18,532.6		$ (7,278.1)	$ (1,970.5)	245.6
Ending Balance, equity (Accounting Standards Update 2016-13 [Member]) at May. 29, 2022							$ 0.0
Redeemable Interest
Total comprehensive income (loss) attributable to redeemable interests		(29.2)
Decrease (increase) in redemption value of redeemable interest		(14.1)			$ 14.1
Distributions to redeemable interest holder		0.0								$ (129.8)
Ending Balance, Redeemable Noncontrolling Interest, Equity, Other, Fair Value at May. 29, 2022	$ 0.0	$ 0.0