Investments in Joint Ventures (Schedule of combined financial information for the joint ventures on a 100 percent basis) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	May 25, 2014	May 26, 2013	May 27, 2012
Schedule of Equity Method Investments [Line Items]
Net sales	$ 2,494.8	$ 2,552.7	$ 2,581.5
Gross Margin	1,030.3	1,057.3	1,084.1
Earnings before income taxes	219.1	260.3	250.3
Earnings after income taxes	168.8	201.6	189.0
Current assets	1,031.1	976.7
Noncurrent assets	1,129.8	1,088.2
Current liabilities	1,779.0	1,717.4
Noncurrent liabilities	110.3	115.1
Cereal Partners Worldwide [Member]
Schedule of Equity Method Investments [Line Items]
Net sales	2,107.9	2,132.2	2,152.6
Haagen Dazs Japan [Member]
Schedule of Equity Method Investments [Line Items]
Net sales	$ 386.9	$ 420.5	$ 428.9