Restructuring, Impairment, and Other Exit Costs (Schedule of restructuring and other exit cost reserves) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	May 25, 2014	May 26, 2013	May 27, 2012
Restructuring Reserve [Line Items]
Reserve beginning balance	$ 19.5	$ 85.9	$ 7.2
Restructuring charges, including foreign currency translation	6.4	10.6	82.4
Restructuring reserve utilized	(22.4)	(77.0)	(3.7)
Reserve ending balance	3.5	19.5	85.9
Severance [Member]
Restructuring Reserve [Line Items]
Reserve beginning balance	19.5	83.1	1.7
Restructuring charges, including foreign currency translation	6.4	10.6	82.4
Restructuring reserve utilized	(22.4)	(74.2)	(1.0)
Reserve ending balance	3.5	19.5	83.1
Contract Termination [Member]
Restructuring Reserve [Line Items]
Reserve beginning balance	0	2.7	5.5
Restructuring charges, including foreign currency translation	0	0	0
Restructuring reserve utilized	0	(2.7)	(2.8)
Reserve ending balance	0	0	2.7
Other Exit Costs [Member]
Restructuring Reserve [Line Items]
Reserve beginning balance	0	0.1	0
Restructuring charges, including foreign currency translation	0	0	0
Restructuring reserve utilized	0	(0.1)	0.1
Reserve ending balance	$ 0	$ 0	$ 0.1