Note 12 - Stockholders' Equity - Reconciliation of Stockholders' Equity Accounts (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended				6 Months Ended
	Nov. 27, 2022	Aug. 28, 2022	Nov. 28, 2021	Aug. 29, 2021	Nov. 27, 2022	Nov. 28, 2021
Balance	$ 8,576.7	$ 8,862.2	$ 8,635.9	$ 8,631.4	$ 8,862.2	$ 8,631.4
Stock option and incentive plans	39.6	14.9	11.9	(14.8)
Currency translation adjustments	(8.2)	(13.6)	(17.7)	(15.7)
Repurchase of common shares	(100.0)	(50.0)		(50.0)
Derivative adjustments	(6.6)	(2.1)	1.4	(2.1)
Pension and postretirement healthcare benefits	(1.4)	1.4	(0.6)	1.3
Dividends declared on common stock	(157.8)	(158.6)	(149.9)	(149.9)
Net loss attributable to Conagra Brands, Inc.	381.9	(77.5)	275.5	235.4	304.4	510.9
Stock option and incentive plans	39.6	14.9	11.9	(14.8)
Derivative adjustments	6.6	2.1	(1.4)	2.1
Activities of noncontrolling interests	0.3		0.4	0.3
Balance	$ 8,737.7	$ 8,576.7	$ 8,756.9	$ 8,635.9	$ 8,737.7	$ 8,756.9
Common Stock [Member]
Balance (in shares)	584.2	584.2	584.2	584.2	584.2	584.2
Balance	$ 2,921.2	$ 2,921.2	$ 2,921.2	$ 2,921.2	$ 2,921.2	$ 2,921.2
Stock option and incentive plans
Currency translation adjustments
Repurchase of common shares
Derivative adjustments
Pension and postretirement healthcare benefits
Dividends declared on common stock
Net loss attributable to Conagra Brands, Inc.
Stock option and incentive plans
Derivative adjustments
Activities of noncontrolling interests
Balance (in shares)	584.2	584.2	584.2	584.2	584.2	584.2
Balance	$ 2,921.2	$ 2,921.2	$ 2,921.2	$ 2,921.2	$ 2,921.2	$ 2,921.2
Additional Paid-in Capital [Member]
Balance	2,323.0	2,324.6	2,305.0	2,342.1	2,324.6	2,342.1
Stock option and incentive plans	37.9	(1.6)	12.1	(37.1)
Currency translation adjustments
Repurchase of common shares
Derivative adjustments
Pension and postretirement healthcare benefits
Dividends declared on common stock
Net loss attributable to Conagra Brands, Inc.
Stock option and incentive plans	37.9	(1.6)	12.1	(37.1)
Derivative adjustments
Activities of noncontrolling interests
Balance	2,360.9	2,323.0	2,317.1	2,305.0	2,360.9	2,317.1
Retained Earnings [Member]
Balance	6,314.8	6,550.7	6,348.3	6,262.6	6,550.7	6,262.6
Stock option and incentive plans	(2.4)	0.2	(0.6)	0.2
Currency translation adjustments
Repurchase of common shares
Derivative adjustments
Pension and postretirement healthcare benefits
Dividends declared on common stock	(157.8)	(158.6)	(149.9)	(149.9)
Net loss attributable to Conagra Brands, Inc.	381.9	(77.5)	275.5	235.4
Stock option and incentive plans	(2.4)	0.2	(0.6)	0.2
Derivative adjustments
Activities of noncontrolling interests
Balance	6,536.5	6,314.8	6,473.3	6,348.3	6,536.5	6,473.3
AOCI Attributable to Parent [Member]
Balance	(23.4)	(11.2)	(9.4)	5.8	(11.2)	5.8
Stock option and incentive plans
Currency translation adjustments	(6.5)	(11.5)	(16.2)	(14.4)
Repurchase of common shares
Derivative adjustments	(6.6)	(2.1)	1.4	(2.1)
Pension and postretirement healthcare benefits	(1.3)	1.4	(0.6)	1.3
Dividends declared on common stock
Net loss attributable to Conagra Brands, Inc.
Stock option and incentive plans
Derivative adjustments	6.6	2.1	(1.4)	2.1
Activities of noncontrolling interests
Balance	(24.6)	(23.4)	(24.8)	(9.4)	(24.6)	(24.8)
Treasury Stock [Member]
Balance	(3,031.3)	(2,997.6)	(3,008.1)	(2,979.9)	(2,997.6)	(2,979.9)
Stock option and incentive plans	3.6	16.3	0.3	21.8
Currency translation adjustments
Repurchase of common shares	(100.0)	(50.0)		(50.0)
Derivative adjustments
Pension and postretirement healthcare benefits
Dividends declared on common stock
Net loss attributable to Conagra Brands, Inc.
Stock option and incentive plans	3.6	16.3	0.3	21.8
Derivative adjustments
Activities of noncontrolling interests
Balance	(3,127.7)	(3,031.3)	(3,007.8)	(3,008.1)	(3,127.7)	(3,007.8)
Noncontrolling Interest [Member]
Balance	72.4	74.5	78.9	79.6	74.5	79.6
Stock option and incentive plans	0.5		0.1	0.3
Currency translation adjustments	(1.7)	(2.1)	(1.5)	(1.3)
Repurchase of common shares
Derivative adjustments
Pension and postretirement healthcare benefits	(0.1)
Dividends declared on common stock
Net loss attributable to Conagra Brands, Inc.
Stock option and incentive plans	0.5		0.1	0.3
Derivative adjustments
Activities of noncontrolling interests	0.3		0.4	0.3
Balance	$ 71.4	$ 72.4	$ 77.9	$ 78.9	$ 71.4	$ 77.9