Condensed Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Feb. 22, 2015	Feb. 23, 2014	Feb. 22, 2015	Feb. 23, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (952.7)us-gaap_ProfitLoss	$ 236.9us-gaap_ProfitLoss	$ (452.3)us-gaap_ProfitLoss	$ 636.5us-gaap_ProfitLoss
Derivative adjustments, net of tax:
Unrealized derivative adjustments	0	(8.1)	0	31.2
Reclassification for derivative adjustments included in net income	0	34.4	(0.3)	34.5
Unrealized gains (losses) on available-for-sale securities, net of tax	0.2	(0.2)	0.4	0.2
Unrealized currency translation losses	(82.8)	(29.5)	(135.6)	(50.5)
Pension and post-employment benefit obligations, net of tax:
Unrealized pension and post-employment benefit obligations	0	0	2.9	0.2
Reclassification for pension and post-employment benefit obligations included in net income	(0.1)	0.6	(0.4)	1.6
Comprehensive income (loss)	(1,035.4)	234.1	(585.3)	653.7
Less: Comprehensive income (loss) attributable to noncontrolling interests	0.7	3.2	3.9	(0.1)
Comprehensive income (loss) attributable to ConAgra Foods, Inc.	$ (1,036.1)us-gaap_ComprehensiveIncomeNetOfTax	$ 230.9us-gaap_ComprehensiveIncomeNetOfTax	$ (589.2)us-gaap_ComprehensiveIncomeNetOfTax	$ 653.8us-gaap_ComprehensiveIncomeNetOfTax

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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