Retirement Benefits and Postemployment Benefits (Schedule of summarized financial information about defined benefit pension, other postretirement, and postemployment benefit plans) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	May 25, 2014	May 26, 2013	May 27, 2012
Defined Benefit Pension Plans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets Roll Forward [Abstract]
Fair value at beginning of year	$ 5,066.1	$ 4,353.9
Actual return on assets	740.2	698.7
Employer contributions	25.6	223.1
Plan participant contributions	6.7	15.2
Benefits payments	(231.4)	(222.6)
Foreign currency	4.6	(2.2)
Fair value at end of year	5,611.8	5,066.1	4,353.9
Defined Benefit Plan, Change in Projected Benefit Obligation Roll Forward [Abstract]
Benefit obligation at beginning of year	5,381.4	4,991.5
Service cost	133.0	124.4	114.3
Interest cost	239.5	237.3	237.9
Plan amendment	17.8	0.2
Curtailment/other	0	0
Plan participant contributions	6.7	15.2
Medicare Part D reimbursements	0	0
Actuarial loss (gain)	67.6	237.5
Benefits payments	(231.6)	(222.8)
Foreign currency	3.6	(1.9)
Acquisitions	0	0
Projected benefit obligation at end of year	5,618.0	5,381.4	4,991.5
Plan assets less than benefit obligation as of fiscal year end	(6.2)	(315.3)
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets Roll Forward [Abstract]
Fair value at beginning of year	436.9	358.8
Actual return on assets	59.1	67.9
Employer contributions	24.1	0.1
Plan participant contributions	13.5	13.0
Benefits payments	(16.3)	(2.9)
Foreign currency	0	0
Fair value at end of year	517.3	436.9	358.8
Defined Benefit Plan, Change in Projected Benefit Obligation Roll Forward [Abstract]
Benefit obligation at beginning of year	1,148.2	1,129.0
Service cost	22.7	21.6	18.0
Interest cost	50.5	52.1	55.6
Plan amendment	18.2	0
Curtailment/other	(2.9)	0
Plan participant contributions	13.5	13.0
Medicare Part D reimbursements	4.3	4.1
Actuarial loss (gain)	(119.4)	(23.0)
Benefits payments	(59.3)	(58.9)
Foreign currency	(1.0)	(0.1)
Acquisitions	0	10.4
Projected benefit obligation at end of year	1,074.8	1,148.2	1,129.0
Plan assets less than benefit obligation as of fiscal year end	(557.5)	(711.3)
Postemployment Benefit Plans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets Roll Forward [Abstract]
Plan participant contributions	0	0
Defined Benefit Plan, Change in Projected Benefit Obligation Roll Forward [Abstract]
Benefit obligation at beginning of year	145.4	141.3
Service cost	7.7	7.8	7.5
Interest cost	4.1	4.4	4.8
Plan amendment	0	4.5
Curtailment/other	3.7	11.4
Plan participant contributions	0	0
Medicare Part D reimbursements	0	0
Actuarial loss (gain)	1.8	(10.4)
Benefits payments	(17.2)	(13.6)
Foreign currency	(0.2)	0
Acquisitions	0	0
Projected benefit obligation at end of year	145.3	145.4	141.3
Plan assets less than benefit obligation as of fiscal year end	$ (145.3)	$ (145.4)