Quarterly Data (Unaudited) (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	May 29, 2016	May 28, 2017	May 29, 2016	May 31, 2015
QUARTERLY DATA (UNAUDITED) [Abstract]
Effective income tax rate	19.20%	28.80%	31.40%	33.30%
Divestitures [Line Items]
Pre-tax gain (loss) on sale of business		$ (13.5)	$ 148.2	$ 0.0
General Mills de Venezuela CA Subsidiary [Member]
Divestitures [Line Items]
Pre-tax gain (loss) on sale of business	$ (37.6)
General Mills Argentina S.A. Foodservice Business [Member]
Divestitures [Line Items]
Pre-tax gain (loss) on sale of business	$ (14.8)