RESTRUCTURING ACTIVITIES (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended	16 Months Ended	12 Months Ended
	May 25, 2014 SCAE Plan	May 25, 2014 SCAE Plan	May 25, 2014 Network Optimization Plan	May 25, 2014 Acquisition-Related Restructuring	May 25, 2014 Administrative Efficiency Restructuring Plan	May 25, 2014 SCAE Plan	May 25, 2014 2010 Restructuring Plan	May 27, 2012 2010 Restructuring Plan	May 25, 2014 Ralcorp Pre-acquisition Restructuring [Member]	May 25, 2014 Ralcorp Pre-Acquisition Restructure Transactions	May 26, 2013 Ralcorp Pre-Acquisition Restructure Transactions
Restructuring Cost and Reserve [Line Items]
Restructuring And Related Cost Cash Outflows	$ 60.5		$ 17.9	$ 15.5	$ 16.8				$ 1.9
Restructuring And Related Cost Noncash Charges	23.2		58.8	7.9	1.9				1.8
Restructured and related cost incurred to date	112.1		76.7	23.4	18.7		67.3		3.7
Restructuring and related cost expected outflows				23.8
Restructuring and related cost, expected cost		325.0				325.0
Expenses that have resulted or will result in cash outflows				15.9		245.4
Non-cash expenses				7.9		79.6
Restructuring and related cost, incurred cost	$ 83.7							$ 2.6		$ 2.4	$ 1.3