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
	Aug. 26, 2012	Aug. 28, 2011
Defined Benefit Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 31.1	$ 28.5
Interest cost	59.3	59.4
Expected return on plan assets	(107.0)	(110.0)
Amortization of losses	34.0	27.1
Amortization of prior service costs (credits)	1.6	2.1
Other adjustments	0	0
Net (income) expense	19.0	7.1
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	5.3	4.5
Interest cost	12.9	13.9
Expected return on plan assets	(8.0)	(8.9)
Amortization of losses	4.3	3.6
Amortization of prior service costs (credits)	(0.9)	(0.8)
Other adjustments	0	0
Net (income) expense	13.6	12.3
Postemployment Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1.9	1.9
Interest cost	1.1	1.2
Expected return on plan assets	0	0
Amortization of losses	0.5	0.4
Amortization of prior service costs (credits)	0.5	0.5
Other adjustments	2.8	2.3
Net (income) expense	$ 6.8	$ 6.3