The net assets of money purchase plan for certain domestic hourly employees.

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The period of time after a change in control of the company within which the excess pension assets would be allocated to active retirement plan participants.

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Value of common stock issued to a trust (for example, but not limited to, rabbi trust) set up specifically to accumulate stock for the sole purpose of distribution to participating employees.

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Amount of actuarial present value of benefits attributed to employee service rendered, excluding assumptions about future compensation level.

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Amount of actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

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Amount of contribution received by defined benefit plan from employer which increases plan assets.

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Assumed rate, for next fiscal year, based on annual change in cost of health care cost benefits used to measure expected cost of benefits covered by defined benefit postretirement plan. Factors include, but are not limited to, estimate of health care inflation, change in health care utilization or delivery pattern, technological advances, and change in health status of participant. Excludes factors for change in composition of plan population by age and dependency status.

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Amount of accumulated benefit obligation for defined benefit plan with accumulated benefit obligation in excess of plan assets.

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Amount of plan asset for defined benefit plan with accumulated benefit obligation in excess of plan assets.

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Amount of projected benefit obligation for defined benefit pension plan with accumulated benefit obligation in excess of plan assets.

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Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

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Ultimate trend rate for health care cost for defined benefit postretirement plan.

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Year ultimate health care cost trend rate is expected to be reached, in CCYY format.

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Amount of cost for defined contribution plan.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The shares or units in an ESOP trust that have been assigned to individual participant accounts based on a known formula. IRS rules require allocations to be nondiscriminatory generally based on compensation, length of service, or a combination of both. For any particular participant such shares or units may be vested, unvested, or partially vested.

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Retirement Benefits and Postemployment Benefits (Narrative) (Details) - USD ($) shares in Millions	12 Months Ended
	May 30, 2021	May 31, 2020	May 26, 2019
Defined Benefit Plan, Information About Plan Assets
Accumulated benefit obligation	$ 7,402,100,000	$ 7,285,200,000
Rate to which the cost trend rate is assumed to decline (ultimate rate)	4.50%	4.50%
Year that Rate Reaches Ultimate Trend Rate	2029	2029
Defined Contribution Plan Disclosure [Line Items]
Recognized expense	$ 76,100,000	$ 90,100,000	$ 52,700,000
Under Age 65 [Member]
Defined Benefit Plan, Information About Plan Assets
Health care cost trend rate for next year	6.00%	6.20%
Over Age 65 [Member]
Defined Benefit Plan, Information About Plan Assets
Health care cost trend rate for next year	6.30%	6.50%
Defined Benefit Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 33,800,000	$ 32,900,000
Defined Benefit Plan, Information About Plan Assets
Accumulated benefit obligation	556,200,000	3,200,100,000
Projected benefit obligation at end of year	7,714,400,000	7,640,200,000	6,750,700,000
Plan assets at fair value	26,700,000	2,569,900,000
Projected benefit obligation	$ 615,300,000	3,512,900,000
Defined Benefit Pension Plans [Member] \| United States Equities [Member]
Defined Benefit Plan, Information About Plan Assets
Target Allocation, Percentage of Assets Equity Securities	15.00%
Defined Benefit Pension Plans [Member] \| International Equities [Member]
Defined Benefit Plan, Information About Plan Assets
Target Allocation, Percentage of Assets Equity Securities	9.00%
Defined Benefit Pension Plans [Member] \| Private Equities [Member]
Defined Benefit Plan, Information About Plan Assets
Target Allocation, Percentage of Assets Equity Securities	8.00%
Defined Benefit Pension Plans [Member] \| Fixed income [Member]
Defined Benefit Plan, Information About Plan Assets
Target Allocation, Percentage of Assets Equity Securities	57.00%
Defined Benefit Pension Plans [Member] \| Real asset investments [Member]
Defined Benefit Plan, Information About Plan Assets
Target Allocation, Percentage of Assets Equity Securities	12.00%
Defined Benefit Pension Plans [Member] \| United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 0
Defined Benefit Plan, Information About Plan Assets
Retirement Plan Provision Termination Period	5 years
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions		100,000
Defined Benefit Plan, Information About Plan Assets
Accumulated benefit obligation	$ 412,400,000	479,400,000
Projected benefit obligation at end of year	600,000,000.0	773,700,000	824,100,000
Plan assets at fair value	310,100,000	248,000,000.0
Other Postretirement Benefit Plans [Member] \| United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	0
Postemployment Benefit Plans [Member]
Defined Benefit Plan, Information About Plan Assets
Accumulated benefit obligation	151,700,000
Projected benefit obligation at end of year	$ 151,700,000	150,300,000	$ 128,000,000.0
Postemployment Benefit Plans [Member] \| United States Equities [Member]
Defined Benefit Plan, Information About Plan Assets
Target Allocation, Percentage of Assets Equity Securities	28.00%
Postemployment Benefit Plans [Member] \| International Equities [Member]
Defined Benefit Plan, Information About Plan Assets
Target Allocation, Percentage of Assets Equity Securities	14.00%
Postemployment Benefit Plans [Member] \| Private Equities [Member]
Defined Benefit Plan, Information About Plan Assets
Target Allocation, Percentage of Assets Equity Securities	14.00%
Postemployment Benefit Plans [Member] \| Fixed income [Member]
Defined Benefit Plan, Information About Plan Assets
Target Allocation, Percentage of Assets Equity Securities	44.00%
General Mills Savings Plan [Member]
Defined Contribution Plan Disclosure [Line Items]
Net assets of money purchase plan	$ 22,500,000	$ 20,600,000
ESOP number of allocated shares	4.3	4.6
Common stock held by ESOP and company stock fund	$ 433,000,000.0	$ 464,800,000