Investments in Joint Ventures (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	May 27, 2012	May 29, 2011	May 30, 2010
Schedule of Equity Method Investments [Line Items]
Net sales	$ 2,573.4	$ 2,444.9	$ 2,360.0
Cumulative investments	529.0	519.1
JV Goodwill and other intangibles	522.1	597.1
Aggregate advances	268.1	293.3
Sales to joint ventures	10.4	10.2	10.7
Net advances (repayments)	22.2	1.8	128.1
Distributions of earnings from joint ventures	68.0	72.7	88.0
Gross Margin	1,076.0	1,066.3	1,053.2
Earnings before income taxes	250.3	233.4	251.2
Earnings after income taxes	189.0	164.2	202.3
Equity Method Investment Activity At One Hundred Percent	Summary combined financial information for the joint ventures on a 100 percent basis follows:
Current assets	934.8	904.7
Noncurrent assets	1,078.0	1,138.0
Current liabilities	1,671.0	1,690.1
Noncurrent liabilities	91.0	103.3
Cereal Partners Worldwide [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50.00%
Additional Information	We have a 50 percent equity interest in Cereal Partners Worldwide (CPW), which manufactures and markets ready-to-eat cereal products in more than 130 countries and republics outside the United States and Canada. CPW also markets cereal bars in several European countries and manufactures private label cereals for customers in the United Kingdom. We have guaranteed a portion of CPW’s debt and its pension obligation in the United Kingdom.
Net sales	2,152.6	2,067.2	1,997.4
Haagen Dazs Japan [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50.00%
Additional Information	We also have a 50 percent equity interest in Häagen-Dazs Japan, Inc. (HDJ). This joint venture manufactures, distributes, and markets Häagen-Dazs ice cream products and frozen novelties.
Net sales	$ 420.8	$ 377.7	$ 362.6