Supplemental Information (Details) (USD $)
In Millions
 12 Months Ended
May 29, 2011
May 30, 2010
May 31, 2009
Receivables [Abstract]      
From customers $ 1,178.6 $ 1,057.4  
Less allowance for doubtful accounts (16.3) (15.8)  
Total 1,162.3 1,041.6  
Inventory [Abstract]      
Raw materials and packaging 286.2 247.5  
Finished goods 1,273.6 1,131.4  
Grain 218.0 107.4  
Excess of FIFO or weighted-average cost over LIFO cost (168.5) (142.3)  
Total 1,609.3 1,344.0  
LIFO Inventory Amount 1,034.1 958.3  
Prepaid Expenses And Other Assets Current [Abstract]      
Prepaid expenses 161.0 127.5  
Accrued interest receivable, including interest rate swaps 29.0 64.9  
Derivative receivables, primarily commodity-related 109.1 48.8  
Other receivables 104.7 101.4  
Grain Derivative Asset Not Designated As Hedging Instrument Fair Value Current 57.3 11.4  
Miscellaneous 22.4 24.5  
Total 483.5 378.5  
Land Buildings And Equipment [Abstract]      
Land 61.2 58.0  
Buildings 1,777.7 1,653.8  
Buildings under capital lease 25.0 19.6  
Equipment 4,719.7 4,405.6  
Equipment under capital lease 18.9 25.0  
Capitalized Software 367.7 318.7  
Construction in progress 521.9 469.0  
Total land, buildings, and equipment 7,492.1 6,949.7  
Less accumulated depreciation (4,146.2) (3,822.0)  
Total 3,345.9 3,127.7  
Other Noncurrent Assets [Abstract]      
Pension assets 128.6 2.2  
Investments in and advances to joint ventures 519.1 398.1  
Life insurance 87.2 88.2  
Non-current derivative receivables 13.3 130.1  
Miscellaneous 114.3 144.8  
Total 862.5 763.4  
Other Current Liabilities [Abstract]      
Accrued payroll 303.3 331.4  
Accrued interest 114.0 136.5  
Accrued trade and consumer promotions 463.0 555.2  
Accrued taxes 80.4 440.2  
Derivatives payable 34.8 18.1  
Accrued customer advances 36.4 25.5  
Grain Derivative Liability Not Designated As Hedging Instrument Fair Value Current 28.7 12.7  
Miscellaneous 260.9 242.6  
Total 1,321.5 1,762.2  
Other Noncurrent Liabilities [Abstract]      
Interest rate swaps 22.2 180.2  
Accrued compensation and benefits, including obligations for underfunded other postretirement and postemployment benefit plans 1,412.8 1,588.1  
Accrued income taxes 233.3 276.3  
Miscellaneous 64.9 74.1  
Total 1,733.2 2,118.7  
Earnings Supplemental [Abstract]      
Depreciation and amortization 472.6 457.1 453.6
Research and development expense 235.0 218.3 208.2
Advertising and media expense (including production and communication costs) 843.7 908.5 732.1
Interest Net [Abstract]      
Interest expense 360.9 374.5 409.5
Capitalized interest (7.2) (6.2) (5.1)
Interest income (7.4) (6.8) (21.6)
Loss on debt repurchase 0 40.1 0
Total 346.3 401.6 382.8
Cash Flows [Abstract]      
Cash interest payments 333.1 384.1 292.8
Cash paid for income taxes 699.3 672.5 395.3
Shares issued for acquisition, value     55.0
Humm Foods [Member]
      
Cash Flows [Abstract]      
Shares issued for acquisition, value     $ 55.0
Shares issued for acquisition, shares     1.8