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 [Member]	Noncontrolling Interest [Member]	Total
Balance (in shares) at May. 26, 2019	584.2
Balance at May. 26, 2019	$ 2,921.2	$ 2,286.0	$ 5,047.9	$ (110.3)	$ (2,760.2)	$ 79.1	$ 7,463.7
Stock option and incentive plans		37.2	(2.9)		30.3		64.6
Currency translation adjustments				(34.8)		(6.5)	(41.3)
Derivative adjustments				(7.7)			(7.7)
Activities of noncontrolling interests						2.0	2.0
Pension and postretirement healthcare benefits				43.2			43.2
Dividends declared on common stock			(413.9)				(413.9)
Net income attributable to Conagra Brands, Inc. common stockholders:			840.1				840.1
Pension and postretirement healthcare benefits				(43.2)			(43.2)
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
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
Repurchase of common shares					(298.1)		(298.1)
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)
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
Repurchase of common shares					(50.0)		(50.0)
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