Supplemental Information (Schedule of certain Consolidated Balance Sheet accounts) (Details) - USD ($) $ in Millions		May 28, 2017	May 29, 2016	May 31, 2015	May 25, 2014
Receivables [Abstract]
Customers		$ 1,454.4	$ 1,390.4
Less allowance for doubtful accounts		(24.3)	(29.6)
Total		1,430.1	1,360.8
Inventories [Abstract]
Raw materials and packaging		395.4	397.3
Finished goods		1,224.3	1,163.1
Grain		73.0	72.6
Excess of FIFO over LIFO cost	[1]	(209.1)	(219.3)
Total		1,483.6	1,413.7
LIFO Inventory Amount		893.8	841.0
Prepaid Expenses and Other Current Assets [Abstract]
Other receivables		163.7	159.3
Prepaid expenses		168.9	177.9
Derivative receivables, primarily commodity-related		35.0	44.6
Grain contracts		2.7	1.8
Miscellaneous		11.3	15.4
Total		381.6	399.0
Land, Buildings and Equipment [Abstract]
Land		79.8	92.9
Buildings		2,249.2	2,236.0
Equipment		6,095.9	5,945.6
Capitalized software		545.4	523.0
Construction in progress		553.0	702.7
Total land, buildings, and equipment		9,526.6	9,503.5
Less accumulated depreciation		(5,838.9)	(5,759.9)
Total		3,687.7	3,743.6
Other Assets [Abstract]
Investments in and advances to joint ventures		505.3	518.9
Pension assets		144.9	90.9
Exchangeable note with related party		0.0	12.7
Life insurance		25.6	26.3
Miscellaneous		110.1	102.9
Total		785.9	751.7
Other Current Liabilities [Abstract]
Accrued trade and consumer promotions		482.6	563.7
Accrued payroll		326.6	386.4
Dividends payable		21.5	23.8
Accrued taxes		58.0	110.5
Accrued interest, including interest rate swaps		83.8	90.4
Grains contracts		5.6	5.5
Restructuring and other exit costs reserve		85.0	76.6	$ 120.8	$ 3.5
Derivative payable		18.1	35.6
Miscellaneous		291.0	302.5
Total		1,372.2	1,595.0
Other Noncurrent Liabilities [Abstract]
Accrued compensation and benefits, including obligations for underfunded other postretirement benefit and postemployment benefit plans		1,249.7	1,755.0
Accrued taxes		162.3	204.0
Miscellaneous		111.1	128.6
Total		1,523.1	2,087.6
Buildings [Member]
Land, Buildings and Equipment [Abstract]
Capital leased assets		0.3	0.3
Equipment [Member]
Land, Buildings and Equipment [Abstract]
Capital leased assets		$ 3.0	$ 3.0

[1] Inventories of $893.8 million as of May 28, 2017 , and $841.0 million as of May 29, 2016 , were valued at LIFO. The difference between replacement cost and the stated LIFO inventory value is not materially different from the reserve for the LIFO valuation meth od.