RESTRUCTURING (Liabilities for Initiatives and Changes) (Details) (Ralcorp Restructuring, USD $) In Millions, unless otherwise specified	3 Months Ended
	Aug. 25, 2013
Restructuring Cost and Reserve [Line Items]
Beginning balance	$ 28.4
Costs incurred and charged to expense	7.3
Costs paid or otherwise settled	(3.4)
Ending balance	32.3
Severance and Related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Beginning balance	17.2
Costs incurred and charged to expense	7.0
Costs paid or otherwise settled	(3.1)
Ending balance	21.1
Multi-employer Pension Cost [Member]
Restructuring Cost and Reserve [Line Items]
Beginning balance	11.2
Costs incurred and charged to expense	0.3
Costs paid or otherwise settled	(0.3)
Ending balance	$ 11.2