SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Summary of Reclassifications From Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
Aug. 25, 2019	Oct. 26, 2018	Aug. 26, 2018
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Interest expense, net	$ (122.7)		$ (49.0)
Pension and postretirement non-service income	400.8		257.3
Income before income taxes and equity method investment earnings	150.5		219.4
Income tax expense	11.5		(57.4)
Net income attributable to Conagra Brands, Inc.	173.8	$ 178.2	178.2
Reclassification out of accumulated other comprehensive loss \| Cash flow hedges
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Interest expense, net	(0.8)		0.0
Income before income taxes and equity method investment earnings	(0.8)		0.0
Income tax expense	0.2		0.0
Net income attributable to Conagra Brands, Inc.	(0.6)		0.0
Reclassification out of accumulated other comprehensive loss \| Net prior service cost
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Pension and postretirement non-service income	0.2		0.2
Reclassification out of accumulated other comprehensive loss \| Net actuarial gain
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Pension and postretirement non-service income	(1.2)		(0.4)
Reclassification out of accumulated other comprehensive loss \| Pension and postretirement liabilities
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Income before income taxes and equity method investment earnings	(0.4)		(0.2)
Income tax expense	0.1		0.1
Net income attributable to Conagra Brands, Inc.	(0.3)		(0.1)
Reclassification out of accumulated other comprehensive loss \| Curtailment
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Pension and postretirement non-service income	$ 0.6		$ 0.0

Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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