XML 120 R105.htm IDEA: XBRL DOCUMENT
v3.10.0.1

PENSION AND POSTRETIREMENT BENEFITS - Narrative (Details) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Nov. 26, 2017 | May 27, 2018 | May 28, 2017 | May 29, 2016 | Sep. 30, 2017 | Aug. 27, 2017 | Dec. 31, 2016 | Nov. 09, 2016
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |
Expense resulting from special termination benefits granted |  |  |  | $ 25.6 |  |  |  |
Expense related to expected incurrence of certain multi-employer plan withdrawal costs |  | $ 0.6 | $ 4.0 | 31.8 |  |  |  |
Fair value of certain investments |  | 487.2 |  |  |  |  |  |
Fair value of funds which have imposed such gates |  | 0.1 |  |  |  |  |  |
Additional expense related to expected incurrence of certain withdrawal costs |  | 0.6 | 4.0 | 31.8 |  |  |  |
Expense related to defined contribution plans |  | $ 24.5 | $ 18.0 | 35.4 |  |  |  |
Generally less than |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |
Maximum allowable funding percentage to be in critical status |  | 65.00% |  |  |  |  |  |
Maximum allowable funding percentage to be in endangered status status |  | 80.00% |  |  |  |  |  |
Generally at least |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |
Minimum required funding percentage to be in the green zone |  | 80.00% |  |  |  |  |  |
Percentage of plan's total contribution under Forms 5500 (more than) |  | 5.00% |  |  |  |  |  |
Private equity funds |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |
Unfunded commitments for additional investments |  | $ 65.4 |  |  |  |  |  |
Natural resources funds |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |
Unfunded commitments for additional investments |  | $ 26.7 |  |  |  |  |  |
Fixed income securities |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |
Target allocation (percent) |  | 90.00% |  |  |  |  |  |
Return seeking securities |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |
Target allocation (percent) |  | 10.00% |  |  |  |  |  |
Pension Benefits |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |
Effective discount rate assumption |  | 4.14% | 3.90% |  |  |  | 4.11% |
Decrease to underfunded status of the pension plans |  | $ 79.5 | $ 18.1 |  |  |  |  |
Charge reflecting year-end write-off of actuarial losses | $ 3.4 | 3.4 | 1.2 | 348.5 |  |  |  |
Accumulated benefit obligation |  | 3,400.0 | 3,500.0 |  |  |  |  |
Lump-sum settlement payments |  | 10.2 | 287.5 |  |  |  |  |
Settlement charge |  | 1.3 | 13.8 | 0.0 |  |  |  |
Benefit to accumulated other comprehensive income (loss) |  |  | 62.2 |  |  |  |  |
Expense resulting from special termination benefits granted |  | 0.0 | 1.5 | 25.6 |  |  |  |
Pre-tax reduction in total pension benefit cost associated with change in accounting estimate |  | (49.0) | $ (0.9) | 413.7 |  |  |  |
Anticipated contributions to plans in fiscal 2018 |  | $ 19.6 |  |  |  |  |  |
Other Benefits |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |
Effective discount rate assumption |  | 3.81% | 3.33% |  |  |  |  |
Decrease to underfunded status of the pension plans |  | $ 0.0 | $ 0.0 |  |  |  |  |
Lump-sum settlement payments |  | 0.0 | 0.0 |  |  |  |  |
Settlement charge |  | 0.0 | 0.0 | 0.0 |  |  |  |
Expense resulting from special termination benefits granted |  | 0.0 | 0.0 | 0.0 |  |  |  |
Pre-tax reduction in total pension benefit cost associated with change in accounting estimate |  | 0.7 | (1.2) | $ 0.2 |  |  |  |
Anticipated contributions to plans in fiscal 2018 |  | $ 16.2 |  |  |  |  |  |
Spinoff | Pension Benefits |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |
Effective discount rate assumption |  |  |  | 3.86% | 3.78% | 3.90% |  | 4.04%
Decrease to underfunded status of the pension plans | 43.5 |  | 66.0 |  |  |  |  |
Pension curtailment gain (charge) within other comprehensive income (loss) | $ (0.7) |  | 19.5 |  |  |  |  |
Discontinued operations |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |
Expense related to expected incurrence of certain multi-employer plan withdrawal costs |  |  | 2.1 | $ 2.0 |  |  |  |
Restructuring activities |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |
Expense related to expected incurrence of certain multi-employer plan withdrawal costs |  |  | 1.9 | $ 29.8 |  |  |  |
Change in Assumptions for Defined Benefit Plans | Pension Benefits |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |
Pre-tax reduction in total pension benefit cost associated with change in accounting estimate |  |  | $ 27.0 |  |  |  |  |

X
- Definition Benefit cost. + References No definition available. + Details
Name: | cag_BenefitCost
Namespace Prefix: | cag_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Defined Benefit Plan, Recognized Net Actuarial Gain (Loss) + References No definition available. + Details
Name: | cag_DefinedBenefitPlanRecognizedNetActuarialGainLoss
Namespace Prefix: | cag_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Fair value investments ability to impose customary redemption gates. + References No definition available. + Details
Name: | cag_FairValueInvestmentsAbilityToImposeCustomaryRedemptionGates
Namespace Prefix: | cag_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value investments impose customary redemption gates. + References No definition available. + Details
Name: | cag_FairValueInvestmentsImposeCustomaryRedemptionGates
Namespace Prefix: | cag_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Green zone multiemployer plan funded percentage. + References No definition available. + Details
Name: | cag_GreenZoneMultiemployerPlanFundedPercentage
Namespace Prefix: | cag_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The expected incurrence of certain withdrawal costs related to multiemployer plans. + References No definition available. + Details
Name: | cag_MultiemployerPlansExpectedWithdrawalCosts
Namespace Prefix: | cag_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Multiemployer Plans, Withdrawal Costs + References No definition available. + Details
Name: | cag_MultiemployerPlansWithdrawalCosts
Namespace Prefix: | cag_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage providing more than plans total contribution. + References No definition available. + Details
Name: | cag_PercentageProvidingMoreThanPlansContribution
Namespace Prefix: | cag_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Red zone multiemployer plans funded percentage. + References No definition available. + Details
Name: | cag_RedZoneMultiemployerPlansFundedPercentage
Namespace Prefix: | cag_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Unfunded commitment for additional investment. + References No definition available. + Details
Name: | cag_UnfundedCommitmentForAdditionalInvestment
Namespace Prefix: | cag_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Yellow zone multiemployer plans funded percentage. + References No definition available. + Details
Name: | cag_YellowZoneMultiemployerPlansFundedPercentage
Namespace Prefix: | cag_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of actuarial present value of benefits attributed to employee service rendered, excluding assumptions about future compensation level. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of (increase) decrease in accumulated benefit obligation of defined benefit plan from effects of settlement and curtailment. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (r) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanAccumulatedBenefitObligationIncreaseDecreaseForSettlementAndCurtailment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(1) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of cost of providing special or contractual termination benefits payable from defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (q) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanCostOfProvidingSpecialOrContractualTerminationBenefitRecognizedDuringPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of (increase) decrease in benefit obligation of defined benefit plan from event reducing expected years of future service of present employees or eliminating accrual of benefits for some or all future services of present employees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a)(10) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanCurtailments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of contributions expected to be received by defined benefit plan from employer in fiscal year. Excludes contributions paid by employer in current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e2709-114920 + Details
Name: | us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsRemainderOfFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(5)(i) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of gain (loss) recognized in net periodic benefit (cost) credit from irrevocable action relieving primary responsibility for benefit obligation and eliminating risk related to obligation and assets used to effect settlement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(7) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of payment, which decreases plan assets of defined benefit plan, for irrevocable action relieving primary responsibility for benefit obligation and eliminating risk for obligation and assets used to effect settlement. Transaction constituting settlement includes, but is not limited to, making lump-sum cash payment to participant in exchange for their rights to receive specified benefits and purchasing nonparticipating annuity contract. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(5)(ii) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(5)(iv)(01) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(8) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanSettlementsPlanAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of cost for defined contribution plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 70 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942 + Details
Name: | us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, before tax, of increase (decrease) to other comprehensive income from settlement and curtailment gain (loss) of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e637-108580 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e689-108580 + Details
Name: | us-gaap_OtherComprehensiveIncomeLossFinalizationOfPensionAndNonPensionPostretirementPlanValuationBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_PrivateEquityFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=cag_PrivateEnergyFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_FixedIncomeSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DisposalGroupClassificationAxis=us-gaap_DiscontinuedOperationsDisposedOfByMeansOtherThanSaleSpinoffMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=cag_RecordedInDiscontinuedOperationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=cag_RecordedInRestructuringActivitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ChangeInAccountingEstimateByTypeAxis=us-gaap_ChangeInAssumptionsForPensionPlansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |