EARNINGS PER SHARE - Computation of basic and diluted earnings per common share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended	6 Months Ended
Nov. 27, 2016	Nov. 29, 2015	Nov. 27, 2016	Nov. 29, 2015
Numerator:
Net income attributable to Lamb Weston Holdings, Inc	$ 87.2	$ 73.3	$ 166.8	$ 135.3
Less: Increase in redemption value of noncontrolling interests in excess of earnings allocated	0.5	0.4	0.9	0.9
Net income available to Lamb Weston common stockholders	$ 86.7	$ 72.9	$ 165.9	$ 134.4
Denominator:
Basic weighted average common shares outstanding	146.0	146.0	146.0	146.0
Add: Dilutive effect of stock options, restricted stock units, and other dilutive securities	0.3		0.3
Diluted weighted average common shares outstanding	146.3	146.0	146.3	146.0
Earning per share
Basic	$ 0.59	$ 0.50	$ 1.14	$ 0.92
Diluted	$ 0.59	$ 0.50	$ 1.13	$ 0.92

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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Change in noncontrolling interest during the period as a result of a change in the redemption value of redeemable noncontrolling interest.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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Net Income or Loss Available to Common Stockholders plus adjustments resulting from the assumption that dilutive convertible securities were converted, options or warrants were exercised, or that other shares were issued upon the satisfaction of certain conditions.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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