SHARE-BASED PAYMENTS (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
May 26, 2013	May 27, 2012	May 29, 2011
Share Based Payments (Textual) [Abstract]
Shares issued under the plan	16,700,000
Stock option granted	3,900,000	4,100,000	6,200,000
Cash received from option exercises	$ 259.8	$ 217.8	$ 71.6
Actual tax benefit realized for the tax deductions from option exercises	28.7	15.4	3.4
Shares units granted	1,000,000	1,800,000	1,600,000
Closing market price of our common stock	$ 34.77
ConAgra foods 2009 stock plan
Share Based Payments (Textual) [Abstract]
Shares issued under the plan	29,500,000
Stock Options
Share Based Payments (Textual) [Abstract]
Weighted average grant date fair value, options	$ 2.93	$ 3.26	$ 3.31
Total intrinsic value of share units vested	77.2	41.5	9.3
Compensation expense	12.8	15.4	19.9
Tax benefit related to Compensation expense	4.8	5.7	7.4
Unrecognized compensation expense	10.0
Weighted average period	1 year 2 months 12 days
Share Unit Plans
Share Based Payments (Textual) [Abstract]
Compensation expense	26.7	25.5	21.2
Total intrinsic value of share units vested, other than options	24.3	23.2	14.5
Tax benefit related to Compensation expense	9.9	9.5	7.9
Unrecognized compensation expense	45.0
Weighted average grant date fair value	$ 25.59	$ 26.11	$ 21.55
Weighted average period	1 year 9 months 24 days
Cash-Settled Share Unit
Share Based Payments (Textual) [Abstract]
Compensation expense	8.0
Tax benefit related to Compensation expense	3.0
Weighted average grant date fair value	$ 24.74
Shares units granted	920,000
Share-Settled Share Unit
Share Based Payments (Textual) [Abstract]
Weighted average grant date fair value	$ 25.59
Performance based share plan
Share Based Payments (Textual) [Abstract]
Compensation expense	19.9	0.8	4.0
Total intrinsic value of share units vested, other than options		16.0	7.4
Tax benefit related to Compensation expense	7.4	0.3	1.5
Unrecognized compensation expense	15.0
Weighted average period	1 year 7 months 6 days
Restricted cash plan
Share Based Payments (Textual) [Abstract]
Cash flows decrease and net financing cash flow increase	$ (21.3)	$ (8.7)
Performance period ending 2013
Share Based Payments (Textual) [Abstract]
Percentage of the targeted number of performance shares, minimum range and will be paid in shares of common stock	0.00%
Percentage of the targeted number of performance shares, maximum range and will be paid in shares of common stock	200.00%
Performance period ending 2014
Share Based Payments (Textual) [Abstract]
Percentage of the targeted number of performance shares, minimum range and will be paid in shares of common stock	0.00%
Percentage of the targeted number of performance shares, maximum range and will be paid in shares of common stock	220.00%
Percentage of target incentive required payout	25.00%

Percentage of the targeted number of performance shares maximum range and will be paid in shares of common stock.

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Percentage of the targeted number of performance shares, minimum range and will be paid in shares of common stock.

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Percentage of target incentive required payout.

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Share based compensation arrangement by share based payment award, equity instruments other than options, outstanding, exercises in period, total intrinsic value

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Unrecognized compensation expense.

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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Aggregate proceeds received by the entity during the annual period from exercises of stock or unit options and conversion of similar instruments granted under equity-based payment arrangements.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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Disclosure of the aggregate tax benefit realized from the exercise of stock options and the conversion of similar instruments during the annual period.

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Amount of excess tax benefit (tax deficiency) that arises when compensation cost from non-qualified equity-based compensation recognized on the entity's tax return exceeds (is less than) compensation cost from equity-based compensation recognized in financial statements. Excess tax benefit (tax deficiency) reduces (increases) net cash provided by operating activities.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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The total accumulated difference between fair values of underlying shares on dates of exercise and exercise price on options which were exercised (or share units converted) into shares during the reporting period under the plan.

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Net number of share options (or share units) granted during the period.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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Price of a single share of a number of saleable stocks of a company.

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