Retirement and Postemployment Benefits (Schedule of components of net pension, other postretirement, and postemployment (income) expense) (Details) - USD ($) $ in Millions	3 Months Ended
	Aug. 26, 2018	Aug. 27, 2017
Defined Benefit Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 23.7	$ 23.9
Interest cost	62.0	55.4
Expected return on plan assets	(111.5)	(119.1)
Amortization of losses	27.5	44.1
Amortization of prior service costs (credits)	0.4	0.5
Other adjustments	0.0	0.0
Net expense (income)	2.1	4.8
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2.4	2.8
Interest cost	8.3	7.7
Expected return on plan assets	(10.1)	(13.0)
Amortization of losses	0.2	0.2
Amortization of prior service costs (credits)	(1.4)	(1.4)
Other adjustments	0.0	0.0
Net expense (income)	(0.6)	(3.7)
Postemployment Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1.9	2.1
Interest cost	0.7	0.6
Expected return on plan assets	0.0	0.0
Amortization of losses	0.1	0.2
Amortization of prior service costs (credits)	0.1	0.2
Other adjustments	2.8	3.4
Net expense (income)	$ 5.6	$ 6.5