Consolidated Statements of Common Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Treasury Stock, Common [Member]	Noncontrolling Interest [Member]	Total
Balance (in shares) at May. 31, 2020	584.2
Balance (Accounting Standards Update 2016-13 [Member]) at May. 31, 2020			$ (1.1)				$ (1.1)
Balance at May. 31, 2020	2,921.2	2,323.2	5,471.2	(109.6)	(2,729.9)	74.6	7,950.7
Stock option and incentive plans		18.9	(3.1)		48.1	0.2	64.1
Currency translation adjustments				48.6		3.2	51.8
Repurchase of common shares					(298.1)		(298.1)
Derivative adjustments				(2.0)			(2.0)
Activities of noncontrolling interests						1.6	1.6
Pension and postretirement healthcare benefits				68.8			68.8
Dividends declared on common stock			(503.2)				(503.2)
Net income attributable to Conagra Brands, Inc. common stockholders:			1,298.8				1,298.8
Pension and postretirement healthcare benefits				(68.8)			(68.8)
Balance (in shares) at May. 30, 2021	584.2
Balance at May. 30, 2021	$ 2,921.2	2,342.1	6,262.6	5.8	(2,979.9)	79.6	8,631.4
Stock option and incentive plans		(17.5)	(0.3)		32.3	0.4	14.9
Currency translation adjustments				(18.0)		(5.5)	(23.5)
Repurchase of common shares					(50.0)		(50.0)
Derivative adjustments				5.5			5.5
Pension and postretirement healthcare benefits				4.5			4.5
Dividends declared on common stock			(599.8)				(599.8)
Net income attributable to Conagra Brands, Inc. common stockholders:			888.2				888.2
Pension and postretirement healthcare benefits				(4.5)			(4.5)
Balance (in shares) at May. 29, 2022	584.2
Balance at May. 29, 2022	$ 2,921.2	2,324.6	6,550.7	(11.2)	(2,997.6)	74.5	8,862.2
Stock option and incentive plans		52.3	(3.7)		31.3	2.1	82.0
Currency translation adjustments				(4.6)		(5.2)	(9.8)
Repurchase of common shares					(150.0)		(150.0)
Derivative adjustments				(0.6)			(0.6)
Activities of noncontrolling interests						(0.8)	(0.8)
Pension and postretirement healthcare benefits				28.0		0.1	28.1
Dividends declared on common stock			(631.2)				(631.2)
Net income attributable to Conagra Brands, Inc. common stockholders:			683.6				683.6
Pension and postretirement healthcare benefits				(28.0)		(0.1)	(28.1)
Balance (in shares) at May. 28, 2023	584.2
Balance at May. 28, 2023	$ 2,921.2	$ 2,376.9	$ 6,599.4	$ (44.4)	$ (3,116.3)	$ 70.5	$ 8,807.3