RESTRUCTURING (Consolidated Amounts) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	May 26, 2013
Administrative Efficiency Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	$ 2.0
Restructured and related cost incurred to date	18.7
Administrative Efficiency Restructuring Plan | Consumer Foods
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	1.6
Restructured and related cost incurred to date	13.8
Administrative Efficiency Restructuring Plan | Commercial Foods
Restructuring Cost and Reserve [Line Items]
Restructured and related cost incurred to date	1.0
Administrative Efficiency Restructuring Plan | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0.4
Restructured and related cost incurred to date	3.9
Acquisition-Related Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	9.5
Restructured and related cost incurred to date	14.0
Acquisition-Related Restructuring | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	2.5
Restructured and related cost incurred to date	2.5
Acquisition-Related Restructuring | Consumer
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	7.0
Restructured and related cost incurred to date	11.5
Ralcorp Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	28.4
Ralcorp Restructuring | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	28.4
Network Optimization Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	4.3
Restructured and related cost incurred to date	76.7
Network Optimization Plan | Consumer Foods
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	3.5
Restructured and related cost incurred to date	59.9
Network Optimization Plan | Commercial Foods
Restructuring Cost and Reserve [Line Items]
Restructured and related cost incurred to date	16.0
Network Optimization Plan | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0.8
Restructured and related cost incurred to date	0.8
Multi-employer Pension Cost | Ralcorp Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	11.2
Multi-employer Pension Cost | Ralcorp Restructuring | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	11.2
Cost of Goods, Total | Ralcorp Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	11.2
Cost of Goods, Total | Ralcorp Restructuring | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	11.2
Severance and Related Costs | Administrative Efficiency Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0.9
Restructured and related cost incurred to date	9.3
Severance and Related Costs | Administrative Efficiency Restructuring Plan | Consumer Foods
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0.9
Restructured and related cost incurred to date	7.1
Severance and Related Costs | Administrative Efficiency Restructuring Plan | Commercial Foods
Restructuring Cost and Reserve [Line Items]
Restructured and related cost incurred to date	0
Severance and Related Costs | Administrative Efficiency Restructuring Plan | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0
Restructured and related cost incurred to date	2.2
Severance and Related Costs | Acquisition-Related Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	4.7
Restructured and related cost incurred to date	9.0
Severance and Related Costs | Acquisition-Related Restructuring | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0
Restructured and related cost incurred to date	0
Severance and Related Costs | Acquisition-Related Restructuring | Consumer
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	4.7
Restructured and related cost incurred to date	9.0
Severance and Related Costs | Ralcorp Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	17.2
Severance and Related Costs | Ralcorp Restructuring | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	17.2
Severance and Related Costs | Network Optimization Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	(1.8)
Restructured and related cost incurred to date	7.8
Severance and Related Costs | Network Optimization Plan | Consumer Foods
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	(1.8)
Restructured and related cost incurred to date	7.7
Severance and Related Costs | Network Optimization Plan | Commercial Foods
Restructuring Cost and Reserve [Line Items]
Restructured and related cost incurred to date	0.1
Severance and Related Costs | Network Optimization Plan | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0
Restructured and related cost incurred to date	0
Asset Impairment Charge | Acquisition-Related Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	4.1
Restructured and related cost incurred to date	4.1
Asset Impairment Charge | Acquisition-Related Restructuring | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	2.5
Restructured and related cost incurred to date	2.5
Asset Impairment Charge | Acquisition-Related Restructuring | Consumer
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	1.6
Restructured and related cost incurred to date	1.6
Asset Impairment Charge | Network Optimization Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	1.4
Restructured and related cost incurred to date	29.3
Asset Impairment Charge | Network Optimization Plan | Consumer Foods
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	1.4
Restructured and related cost incurred to date	15.3
Asset Impairment Charge | Network Optimization Plan | Commercial Foods
Restructuring Cost and Reserve [Line Items]
Restructured and related cost incurred to date	14.0
Asset Impairment Charge | Network Optimization Plan | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0
Restructured and related cost incurred to date	0
Other, Net | Administrative Efficiency Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0.7
Restructured and related cost incurred to date	7.9
Other, Net | Administrative Efficiency Restructuring Plan | Consumer Foods
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0.7
Restructured and related cost incurred to date	6.7
Other, Net | Administrative Efficiency Restructuring Plan | Commercial Foods
Restructuring Cost and Reserve [Line Items]
Restructured and related cost incurred to date	1.0
Other, Net | Administrative Efficiency Restructuring Plan | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0
Restructured and related cost incurred to date	0.2
Other, Net | Acquisition-Related Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0.9
Restructured and related cost incurred to date	0.9
Other, Net | Acquisition-Related Restructuring | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0
Restructured and related cost incurred to date	0
Other, Net | Acquisition-Related Restructuring | Consumer
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0.9
Restructured and related cost incurred to date	0.9
Other, Net | Network Optimization Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	3.1
Restructured and related cost incurred to date	10.8
Other, Net | Network Optimization Plan | Consumer Foods
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	2.3
Restructured and related cost incurred to date	8.5
Other, Net | Network Optimization Plan | Commercial Foods
Restructuring Cost and Reserve [Line Items]
Restructured and related cost incurred to date	1.5
Other, Net | Network Optimization Plan | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0.8
Restructured and related cost incurred to date	0.8
Selling, general and administrative expenses | Administrative Efficiency Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	2.0
Restructured and related cost incurred to date	18.7
Selling, general and administrative expenses | Administrative Efficiency Restructuring Plan | Consumer Foods
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	1.6
Restructured and related cost incurred to date	13.8
Selling, general and administrative expenses | Administrative Efficiency Restructuring Plan | Commercial Foods
Restructuring Cost and Reserve [Line Items]
Restructured and related cost incurred to date	1.0
Selling, general and administrative expenses | Administrative Efficiency Restructuring Plan | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0.4
Restructured and related cost incurred to date	3.9
Selling, general and administrative expenses | Acquisition-Related Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	9.7
Restructured and related cost incurred to date	14.0
Selling, general and administrative expenses | Acquisition-Related Restructuring | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	2.5
Restructured and related cost incurred to date	2.5
Selling, general and administrative expenses | Acquisition-Related Restructuring | Consumer
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	7.2
Restructured and related cost incurred to date	11.5
Selling, general and administrative expenses | Ralcorp Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	17.2
Selling, general and administrative expenses | Ralcorp Restructuring | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	17.2
Selling, general and administrative expenses | Network Optimization Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	1.7
Restructured and related cost incurred to date	46.3
Selling, general and administrative expenses | Network Optimization Plan | Consumer Foods
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0.9
Restructured and related cost incurred to date	29.9
Selling, general and administrative expenses | Network Optimization Plan | Commercial Foods
Restructuring Cost and Reserve [Line Items]
Restructured and related cost incurred to date	15.6
Selling, general and administrative expenses | Network Optimization Plan | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0.8
Restructured and related cost incurred to date	0.8
Accelerated Depreciation | Administrative Efficiency Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0.4
Restructured and related cost incurred to date	1.5
Accelerated Depreciation | Administrative Efficiency Restructuring Plan | Consumer Foods
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0
Restructured and related cost incurred to date	0
Accelerated Depreciation | Administrative Efficiency Restructuring Plan | Commercial Foods
Restructuring Cost and Reserve [Line Items]
Restructured and related cost incurred to date	0
Accelerated Depreciation | Administrative Efficiency Restructuring Plan | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0.4
Restructured and related cost incurred to date	1.5
Accelerated Depreciation | Acquisition-Related Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	(0.2)
Accelerated Depreciation | Acquisition-Related Restructuring | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0
Accelerated Depreciation | Acquisition-Related Restructuring | Consumer
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	(0.2)
Accelerated Depreciation | Network Optimization Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	2.0
Restructured and related cost incurred to date	22.5
Accelerated Depreciation | Network Optimization Plan | Consumer Foods
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	2.0
Restructured and related cost incurred to date	22.5
Accelerated Depreciation | Network Optimization Plan | Commercial Foods
Restructuring Cost and Reserve [Line Items]
Restructured and related cost incurred to date	0
Accelerated Depreciation | Network Optimization Plan | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0
Restructured and related cost incurred to date	0
Cost Of Goods Sold | Acquisition-Related Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	(0.2)
Cost Of Goods Sold | Acquisition-Related Restructuring | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0
Cost Of Goods Sold | Acquisition-Related Restructuring | Consumer
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	(0.2)
Cost Of Goods Sold | Network Optimization Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	2.6
Restructured and related cost incurred to date	30.4
Cost Of Goods Sold | Network Optimization Plan | Consumer Foods
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	2.6
Restructured and related cost incurred to date	30.0
Cost Of Goods Sold | Network Optimization Plan | Commercial Foods
Restructuring Cost and Reserve [Line Items]
Restructured and related cost incurred to date	0.4
Cost Of Goods Sold | Network Optimization Plan | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0
Restructured and related cost incurred to date	0
Inventory Write-Offs and Related Costs | Network Optimization Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0.6
Restructured and related cost incurred to date	7.9
Inventory Write-Offs and Related Costs | Network Optimization Plan | Consumer Foods
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0.6
Restructured and related cost incurred to date	7.5
Inventory Write-Offs and Related Costs | Network Optimization Plan | Commercial Foods
Restructuring Cost and Reserve [Line Items]
Restructured and related cost incurred to date	0.4
Inventory Write-Offs and Related Costs | Network Optimization Plan | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0
Restructured and related cost incurred to date	0
Gain (Loss) on Disposition of Property | Network Optimization Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	(1.0)
Restructured and related cost incurred to date	(1.6)
Gain (Loss) on Disposition of Property | Network Optimization Plan | Consumer Foods
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	(1.0)
Restructured and related cost incurred to date	(1.6)
Gain (Loss) on Disposition of Property | Network Optimization Plan | Commercial Foods
Restructuring Cost and Reserve [Line Items]
Restructured and related cost incurred to date	0
Gain (Loss) on Disposition of Property | Network Optimization Plan | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0
Restructured and related cost incurred to date	$ 0