Supplemental Information (Schedule of certain Consolidated Balance Sheet accounts) (Details) (USD $) In Millions, unless otherwise specified	May 25, 2014	May 26, 2013	May 27, 2012	May 29, 2011
Receivables [Abstract]
From customers	$ 1,504.6	$ 1,466.3
Less allowance for doubtful accounts	(21.0)	(19.9)
Total	1,483.6	1,446.4
Inventory, Net [Abstract]
Raw materials and packaging	419.0	403.0
Finished goods	1,260.2	1,228.7
Grain	97.1	135.6
Excess of FIFO over LIFO cost	(216.9)	(221.8)
Total	1,559.4	1,545.5
LIFO Inventory Amount	904.2	897.8
Prepaid Expenses And Other Assets Current [Abstract]
Other receivables	153.9	193.1
Prepaid expenses	187.2	168.6
Derivative receivables, primarily commodity-related	33.3	47.6
Grain contracts	7.5	7.5
Miscellaneous	27.2	20.8
Total	409.1	437.6
Land, Buildings and Equipment [Abstract]
Land	106.9	101.2
Buildings	2,228.4	2,168.3
Buildings under capital lease	0.3	0.3
Equipment	5,979.7	5,731.1
Equipment under capital lease	9.0	9.0
Capitalized software	468.0	427.9
Construction in progress	600.8	495.1
Total land, buildings, and equipment	9,393.1	8,932.9
Less accumulated depreciation	(5,451.2)	(5,054.8)
Total	3,941.9	3,878.1
Other Assets, Noncurrent [Abstract]
Investments in and advances to joint ventures	507.5	478.5
Pension assets	432.2	131.8
Exchangeable note with related party	68.2	88.8
Life insurance	25.8	24.4
Miscellaneous	111.8	120.2
Total	1,145.5	843.7
Other Liabilities, Current [Abstract]
Accrued trade and consumer promotions	578.2	635.3
Accrued payroll	390.1	417.3
Dividends payable	33.5	279.6
Accrued taxes	63.1	88.0
Accrued interest, including interest rate swaps	92.5	91.2
Grains contracts	4.8	30.0
Restructuring and other exit costs reserve	3.5	19.5	85.9	7.2
Derivative payable	23.1	4.1
Miscellaneous	261.1	262.7
Total	1,449.9	1,827.7
Other Liabilities, Noncurrent [Abstract]
Accrued compensation and benefits, including obligations for underfunded other postretirement benefit and postemployment benefit plans	1,341.9	1,560.2
Accrued taxes, noncurrent	195.6	277.1
Miscellaneous	105.7	115.6
Total	$ 1,643.2	$ 1,952.9