RESTRUCTURING ACTIVITIES - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Feb. 24, 2019	Feb. 25, 2018	Feb. 24, 2019	Feb. 25, 2018	Dec. 31, 2018
Pinnacle Integration Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Charges expected to be incurred	$ 255.6		$ 255.6		$ 360.0
Cash charges expected to be incurred					285.0
Non-cash charges expected to be incurred					$ 75.0
Charges incurred or expected to be incurred	255.6		255.6
Cash charges incurred or expected to be incurred	253.7		253.7
Non-cash charges incurred or expected to be incurred	1.9		1.9
Charges that have resulted or will result in cash outflows	35.9		138.2
Non-cash charges	1.0		1.3
Recognized charges	36.9		139.5
Conagra Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Charges incurred or expected to be incurred	4.3		4.3
Cash charges incurred or expected to be incurred	2.4		2.4
Non-cash charges incurred or expected to be incurred	1.9		1.9
Charges that have resulted or will result in cash outflows	0.7		0.7
Non-cash charges	0.3		0.3
Recognized charges	1.0		1.0
SCAE Plan
Restructuring Cost and Reserve [Line Items]
Charges expected to be incurred	472.7		472.7
Cash charges expected to be incurred	322.7		322.7
Non-cash charges expected to be incurred	150.0		150.0
Charges incurred or expected to be incurred	468.9		468.9
Recognized charges	3.5	$ 14.7	8.6	$ 33.2
Cash charges incurred and expected to be incurred	318.9		318.9
Non-cash charges incurred and expected to be incurred	150.0		150.0
Cost of goods sold | SCAE Plan
Restructuring Cost and Reserve [Line Items]
Charges incurred or expected to be incurred	103.2		103.2
Selling, general and administrative expense | SCAE Plan
Restructuring Cost and Reserve [Line Items]
Charges incurred or expected to be incurred	363.4		363.4
Reclassified to Pension and postretirement non-service income | SCAE Plan
Restructuring Cost and Reserve [Line Items]
Charges incurred or expected to be incurred	$ 2.3		$ 2.3