BUSINESS SEGMENTS AND RELATED INFORMATION (Details) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 27, 2016 USD ($)	Nov. 29, 2015 USD ($)	Nov. 27, 2016 USD ($) segment	Nov. 29, 2015 USD ($)
BUSINESS SEGMENTS AND RELATED INFORMATION
Number of operating segments | segment			4
Revenue information
Total net sales	$ 790.7	$ 740.3	$ 1,567.0	$ 1,488.1
Product contribution margin	193.0	154.3	368.9	289.8
Equity method investment earnings	6.2	7.7	16.8	20.2
Total product contribution margin plus equity method investment earnings	199.2	162.0	385.7	310.0
Other selling, general and administrative expenses	67.5	44.8	118.4	95.7
Interest expense, net	6.8	1.5	8.3	2.8
Income tax expense	33.9	38.7	84.9	71.0
Net income	91.0	77.0	174.1	140.5
Less: Income attributable to noncontrolling interests	3.8	3.7	7.3	5.2
Net income attributable to Lamb Weston Holdings, Inc.	87.2	73.3	166.8	135.3
Pretax professional fees expenses	9.0		18.7
Global
Revenue information
Total net sales	412.6	388.3	811.8	771.1
Product contribution margin	92.3	78.9	165.9	134.3
Foodservice
Revenue information
Total net sales	250.6	225.2	510.9	471.5
Product contribution margin	80.2	57.8	159.7	118.0
Retail
Revenue information
Total net sales	96.5	91.8	186.1	179.5
Product contribution margin	20.9	15.4	40.5	28.6
Other
Revenue information
Total net sales	31.0	35.0	58.2	66.0
Product contribution margin	$ (0.4)	$ 2.2	$ 2.8	$ 8.9