Consolidated Statements of Common Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Noncontrolling Interests
Beginning balance (in shares) at May. 29, 2016		567.9
Beginning balance at May. 29, 2016	$ 3,794.8	$ 2,839.7	$ 1,136.3	$ 3,218.3	$ (344.5)	$ (3,136.2)	$ 81.2
Increase (Decrease) in Stockholders' Equity
Stock option and incentive plans	116.4		36.4	(1.3)		81.3
Spinoff of Lamb Weston	796.9			783.3	13.6
Currency translation adjustment, net	(13.4)				(16.6)		3.2
Repurchase of common shares	(1,000.0)					(1,000.0)
Unrealized gain on securities	0.3				0.3
Derivative adjustment, net of reclassification adjustment	(0.7)				(0.7)
Activities of noncontrolling interests	1.8		(0.8)				2.6
Pension and postretirement healthcare benefits	135.0				135.0
Dividends declared on common stock	(388.7)			(388.7)
Net income attributable to Conagra Brands, Inc.	639.3			639.3
Ending balance (in shares) at May. 28, 2017		567.9
Ending balance at May. 28, 2017	4,077.8	$ 2,839.7	1,171.9	4,247.0	(212.9)	(4,054.9)	87.0
Increase (Decrease) in Stockholders' Equity
Stock option and incentive plans	53.7		10.0	(0.8)		44.3	0.2
Spinoff of Lamb Weston	14.8			14.8
Currency translation adjustment, net	0.7				4.6		(3.9)
Repurchase of common shares	(967.3)					(967.3)
Unrealized gain on securities	0.8				0.8
Derivative adjustment, net of reclassification adjustment	2.1				2.1
Activities of noncontrolling interests	(5.5)		(1.9)		(0.7)		(2.9)
Pension and postretirement healthcare benefits	113.0				113.0
Dividends declared on common stock	(341.9)			(341.9)
Net income attributable to Conagra Brands, Inc.	808.4			808.4
Ending balance (in shares) at May. 27, 2018		567.9
Ending balance at May. 27, 2018	3,756.6	$ 2,839.7	1,180.0	4,744.9	(110.5)	(4,977.9)	80.4
Increase (Decrease) in Stockholders' Equity
Stock option and incentive plans	33.1		(6.7)	0.1		39.6	0.1
Currency translation adjustment, net	0.2				2.1		(1.9)
Issuance of treasury shares	2,816.3		638.2			2,178.1
Unrealized gain on securities	0.0
Unrealized gain on securities | ASU 2016-01				0.6	(0.6)
Issuance of common stock (in shares)		16.3
Issuance of common stock	555.7	$ 81.5	474.2
Derivative adjustment, net of reclassification adjustment	32.7				32.7
Activities of noncontrolling interests	0.8		0.3				0.5
Pension and postretirement healthcare benefits	(34.0)				(34.0)
Dividends declared on common stock	(376.5)			(376.5)
Net income attributable to Conagra Brands, Inc.	678.3			678.3
Ending balance (in shares) at May. 26, 2019		584.2
Ending balance at May. 26, 2019	$ 7,463.7	$ 2,921.2	$ 2,286.0	$ 5,047.9	$ (110.3)	$ (2,760.2)	$ 79.1