SEGMENTS - General Financial Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 24, 2019	Nov. 25, 2018	Nov. 24, 2019	Nov. 25, 2018
Segment information
Net sales	$ 1,019.2	$ 911.4	$ 2,008.2	$ 1,826.3
Product contribution margin	279.1	242.9	522.9	467.1
Advertising and promotion expenses	6.0	6.1	10.8	12.5
Gross profit	285.1	249.0	533.7	479.6
Selling, general and administrative expenses	91.6	75.0	170.2	153.0
Income from operations	193.5	174.0	363.5	326.6
Interest expense, net	25.4	26.2	53.6	53.0
Income tax expense	42.7	34.0	79.4	68.3
Equity method investment earnings	15.0	10.2	25.6	30.1
Net income	140.4	124.0	256.1	235.4
Less: Income attributable to noncontrolling interests		5.0		8.6
Net income attributable to Lamb Weston Holdings, Inc.	140.4	119.0	256.1	226.8
Global
Segment information
Net sales	539.6	470.0	1,057.2	936.8
Product contribution margin	128.9	112.4	231.6	206.9
Foodservice
Segment information
Net sales	304.9	279.7	610.3	577.5
Product contribution margin	111.3	97.4	213.8	199.4
Retail
Segment information
Net sales	132.1	123.9	261.4	240.1
Product contribution margin	28.5	25.9	57.4	48.6
Other
Segment information
Net sales	42.6	37.8	79.3	71.9
Product contribution margin	$ 10.4	$ 7.2	$ 20.1	$ 12.2