Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	May 31, 2015	May 29, 2016	May 31, 2015
Tax Credit Carryforward [Line Items]
Valuation allowance	$ 215.4	$ 227.0	$ 215.4
Valuation allowance related to deferred tax asset for losses recorded as part of Pillsbury acquisition		167.9
Valuation allowance related to various state and foreign loss carryforwards		44.1
Tax loss carryforwards		113.1
Unremitted foreign earnings		2,000.0
Foreign earnings repatriated	606.1		606.1
Discrete income tax charge related to foreign earnings repatriated	78.6		78.6
Unrecognized tax benefits that would affect effective tax rate		79.0
Unrecognized tax benefits and accrued interest expected to be paid within the next 12 months		14.7
Tax-related net interest and penalties benefits recognized		2.7	0.2
Tax-related net interest and penalties accrued	$ 35.2	$ 32.1	$ 35.2
Minimum [Member]
Tax Credit Carryforward [Line Items]
Number of open tax years for certain U.S. tax jurisdictions		3 years
Maximum [Member]
Tax Credit Carryforward [Line Items]
Number of open tax years for certain U.S. tax jurisdictions		5 years
Foreign [Member]
Tax Credit Carryforward [Line Items]
Tax loss carryforwards		$ 100.5
Foreign [Member] | No Expiration Date [Member]
Tax Credit Carryforward [Line Items]
Tax loss carryforwards		72.6
Foreign [Member] | Expiration Dates in Year One and Two [Member]
Tax Credit Carryforward [Line Items]
Tax loss carryforwards		4.7
Foreign [Member] | Expiration Dates in Year Three and Beyond [Member]
Tax Credit Carryforward [Line Items]
Tax loss carryforwards		23.2
State [Member]
Tax Credit Carryforward [Line Items]
Tax loss carryforwards		12.6
Capital Loss Carryforward [Member] | Foreign [Member]
Tax Credit Carryforward [Line Items]
Valuation allowance		$ 13.0