Earnings per Share (Schedule of earnings per share) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended	6 Months Ended
Nov. 25, 2012	Nov. 27, 2011	Nov. 25, 2012	Nov. 27, 2011
Earnings Per Share [Abstract]
Net earnings attributable to General Mills	$ 541.6	$ 444.8	$ 1,090.5	$ 850.4
Average number of common shares - basic EPS	648.1	646.3	649.2	647.1
Dilutive Securities [Abstract]
Stock options (a)	11.9	14.8	12.2	14.6
Restricted stock, restricted stock units, and other (a)	4.5	4.7	4.6	4.6
Average number of common shares - diluted EPS	664.5	665.8	666.0	666.3
Earnings per share - basic	$ 0.84	$ 0.69	$ 1.68	$ 1.31
Earnings per share - diluted	$ 0.82	$ 0.67	$ 1.64	$ 1.28

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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-Section 03

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+ Details

- Definition

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.

+ References+ Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Regulation S-X (SX)

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-Publisher FASB

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-Glossary Other Comprehensive Income

-URI http://asc.fasb.org/extlink&oid=6519514

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Reference 8: http://www.xbrl.org/2003/role/presentationRef

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-Glossary Net Income

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-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph A7

-Appendix A

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-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph a

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+ Details

- Definition

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.

+ References+ Details

- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Weighted-Average Number of Common Shares Outstanding

-URI http://asc.fasb.org/extlink&oid=6528421

+ Details