SENIOR LONG-TERM DEBT (Narrative) (Details) (USD $)	3 Months Ended	12 Months Ended																														3 Months Ended	12 Months Ended			3 Months Ended									0 Months Ended		12 Months Ended							12 Months Ended
	Feb. 27, 2011	May 26, 2013	May 27, 2012	May 29, 2011	May 26, 2013 1.35% Senior Debt Due September 2015	Nov. 25, 2012 1.35% Senior Debt Due September 2015	May 27, 2012 1.35% Senior Debt Due September 2015	May 26, 2013 2.1% Senior Debt Due March 2018	Nov. 25, 2012 2.1% Senior Debt Due March 2018	May 27, 2012 2.1% Senior Debt Due March 2018	May 26, 2013 3.25% Senior Debt Due September 2022	Nov. 25, 2012 3.25% Senior Debt Due September 2022	May 27, 2012 3.25% Senior Debt Due September 2022	May 26, 2013 Unsecured Debt	Feb. 24, 2013 Unsecured Debt	May 26, 2013 1.3% Senior Debt Due January 2016	Feb. 24, 2013 1.3% Senior Debt Due January 2016	May 27, 2012 1.3% Senior Debt Due January 2016	May 26, 2013 1.9% Senior Debt Due January 2018	Feb. 24, 2013 1.9% Senior Debt Due January 2018	May 27, 2012 1.9% Senior Debt Due January 2018	May 26, 2013 3.2% Senior Debt Due January 2023	Feb. 24, 2013 3.2% Senior Debt Due January 2023	May 27, 2012 3.2% Senior Debt Due January 2023	May 26, 2013 4.65% Senior Debt Due January 2043	Feb. 24, 2013 4.65% Senior Debt Due January 2043	May 27, 2012 4.65% Senior Debt Due January 2043	May 26, 2013 4.95% Senior Debt Due August 2020 (Including Ralcorp Senior Notes)	May 27, 2012 4.95% Senior Debt Due August 2020 (Including Ralcorp Senior Notes)	May 26, 2013 6.625% Senior Debt Due August 2039 (Including Ralcorp Senior Notes)	May 27, 2012 6.625% Senior Debt Due August 2039 (Including Ralcorp Senior Notes)	Feb. 24, 2013 Term Facility Agreement	May 26, 2013 Term Facility Agreement	May 26, 2013 Ralcorp Senior Debt	Feb. 24, 2013 Base Rate Term Facility Agreement	Feb. 24, 2013 Ralcorp	Feb. 24, 2013 Ralcorp	Feb. 24, 2013 Ralcorp Secured Debt	May 26, 2013 Ralcorp 4.95% Ralcorp Senior Notes	May 26, 2013 Ralcorp 6.625% Senior Notes Ralcorp Due August 2019	May 26, 2013 Ralcorp Ralcorp Notes	Feb. 24, 2013 Ralcorp 7.29% Senior Notes Due August 2018 Issued by Ralcorp	Feb. 24, 2013 Ralcorp 7.39% Senior Notes Due August 2020 Issued by Ralcorp	Feb. 24, 2013 Ralcorp 7.29% Senior Notes Due August 2018 Issued by Ralcorp, Ralcorp Discharged Notes	Feb. 28, 2013 Ralcorp Ralcorp Callable Notes	May 26, 2013 Ralcorp Ralcorp Callable Notes	May 27, 2012 Six Point Seven Five Percent Senior Notes Due September Twenty Eleven	Feb. 24, 2013 Unsecured Debt	Nov. 25, 2012 Unsecured Debt	Nov. 25, 2012 Unsecured Debt Tranche One	Nov. 25, 2012 Unsecured Debt Tranche Two	Nov. 25, 2012 Unsecured Debt Tranche Three	Feb. 24, 2013 Unsecured Debt Ralcorp	May 26, 2013 Revolving Credit Facility	May 26, 2013 Revolving Credit Facility Base Rate
Debt Instrument [Line Items]
Lease financing obligations			$ 30,100,000
Senior unsecured notes														716,000,000	716,000,000																																	3,975,000,000	750,000,000	250,000,000	250,000,000	250,000,000	631,500,000
Interest rate at period end						1.35%			2.10%			3.25%					1.30%			1.90%			3.20%			4.65%		4.95%		6.625%		1.945%							4.95%	6.625%		7.29%	7.39%
Senior notes		9,292,200,000	2,938,800,000		250,000,000		0	250,000,000		0	250,000,000		0			750,000,000	750,000,000	0	1,000,000,000	1,000,000,000	0	1,225,000,000	1,225,000,000	0	1,000,000,000	1,000,000,000	0	300,000,000	0	450,000,000	0			33,900,000				460,700,000	33,900,000	17,200,000	16,700,000		664,500,000	33,000,000		460,700,000
Effective percentage																																								2.83%	4.82%
New term loan facility																																1,500,000,000
Repurchase amount																																												44,800,000
Extinguishment of debt charge																																	600,000,000				1,300,000								562,500,000
Unsecured debt																																1,500,000,000
Cost of extinguishment of debt																																	6,200,000
Term loan repayment percent																																2.50%
Interest rate on borrowings		2.00%																																	1.75%																				1.30%
Interest capitalized		(56,600,000)	0	0																																52,100,000
Debt issuance costs																																				27,300,000
Fair value adjustment		163,800,000
Repayments of long-term debt		2,074,000,000	363,600,000	294,300,000																																											342,700,000
Interest rate		3.25%			1.35%			2.10%			3.25%					1.30%			1.90%			3.20%			4.65%			4.95%		6.625%																	6.75%
Percentage of consolidated capital base if exceeded by funded debt than repay borrowings																																																						75.00%
Fixed charges coverage if range in than repay Borrowings as per multi year revolving credit facility																																																						1.75
Interest paid		215,600,000	211,900,000	231,700,000
Reduction of net interest expense due to impact of interest rate swap contracts		9,200,000	9,900,000	14,500,000
Proceeds from termination of interest rate swap contract	$ 31,500,000