Retirement and Postemployment Benefits (Schedule of components of net pension, other postretirement, and postemployment (income) expense) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Nov. 23, 2014	Nov. 24, 2013	Nov. 23, 2014	Nov. 24, 2013
Defined Benefit Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 34.4	$ 33.3	$ 68.8	$ 66.5
Interest cost	62.4	59.9	124.9	119.7
Expected return on plan assets	(119.2)	(113.9)	(238.5)	(227.7)
Amortization of losses	35.4	38.3	70.8	75.8
Amortization of prior service costs (credits)	1.8	1.4	3.7	2.8
Other adjustments	4.4	0	4.4	0
Settlement or curtailment losses (gains)	10.1	0	10.1	0
Net expense	29.3	19.0	44.2	37.1
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	5.6	5.5	11.2	11.4
Interest cost	11.7	12.5	23.5	25.1
Expected return on plan assets	(10.1)	(8.6)	(20.1)	(17.3)
Amortization of losses	1.3	3.9	2.5	7.7
Amortization of prior service costs (credits)	(0.4)	(0.8)	(0.8)	(1.7)
Other adjustments	0.3	0	0.3	0
Settlement or curtailment losses (gains)	0.8	(2.8)	0.8	(2.8)
Net expense	9.2	9.7	17.4	22.4
Postemployment Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1.9	2.0	3.8	3.9
Interest cost	1.0	1.1	2.1	2.1
Expected return on plan assets	0	0	0	0
Amortization of losses	0.2	0.1	0.4	0.3
Amortization of prior service costs (credits)	0.6	0.6	1.2	1.2
Other adjustments	3.2	2.5	6.3	5.0
Settlement or curtailment losses (gains)	0	0	0	0
Net expense	$ 6.9	$ 6.3	$ 13.8	$ 12.5