XML 104 R88.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Retirement Plans (Fair Values Of The Qualified Plan's Assets) (Details) - USD ($) $ in Thousands | Sep. 30, 2018 | Oct. 01, 2017
--- | --- | ---
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | $ 456,127 |  | $ 460,709
Cash and Cash Equivalents [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 2,901 |  | 3,245
Corporate Bonds [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 160,106 |  | 133,737
High yield |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 14,384 |  | 19,889
Alternatives |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 35,964 |  | 38,933
Real Estate [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 38,008 |  | 35,534
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 168,665 |  | 180,143
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Cash and Cash Equivalents [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [1] | 0 |  | 0
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Corporate Bonds [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [2] | 0 |  | 0
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | High yield |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [3] | 14,384 |  | 19,889
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Alternatives |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [4] | 0 | [5] | 0
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Real Estate [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [5],[6] | 0 |  | 0
Significant Other Observable Inputs (Level 2) [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 163,007 |  | 136,982
Significant Other Observable Inputs (Level 2) [Member] | Cash and Cash Equivalents [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [1] | 2,901 |  | 3,245
Significant Other Observable Inputs (Level 2) [Member] | Corporate Bonds [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [2] | 160,106 |  | 133,737
Significant Other Observable Inputs (Level 2) [Member] | High yield |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [3] | 0 |  | 0
Significant Other Observable Inputs (Level 2) [Member] | Alternatives |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [4] | 0 | [5] | 0
Significant Other Observable Inputs (Level 2) [Member] | Real Estate [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [5],[6] | 0 |  | 0
Significant Unobservable Inputs (Level 3) [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 |  | 0
Significant Unobservable Inputs (Level 3) [Member] | Cash and Cash Equivalents [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [1] | 0 |  | 0
Significant Unobservable Inputs (Level 3) [Member] | Corporate Bonds [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [2] | 0 |  | 0
Significant Unobservable Inputs (Level 3) [Member] | High yield |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [3] | 0 |  | 0
Significant Unobservable Inputs (Level 3) [Member] | Alternatives |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [4] | 0 | [5] | 0
Significant Unobservable Inputs (Level 3) [Member] | Real Estate [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [5],[6] | 0 |  | 0
UNITED STATES | Equity Funds [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 104,424 |  | 108,241
UNITED STATES | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Equity Funds [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [7] | 104,424 |  | 108,241
UNITED STATES | Significant Other Observable Inputs (Level 2) [Member] | Equity Funds [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [7] | 0 |  | 0
UNITED STATES | Significant Unobservable Inputs (Level 3) [Member] | Equity Funds [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [7] | 0 |  | 0
Non-US [Member] | Equity Funds [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 100,340 |  | 121,130
Non-US [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Equity Funds [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [5],[8] | 49,857 |  | 52,013
Non-US [Member] | Significant Other Observable Inputs (Level 2) [Member] | Equity Funds [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [5],[8] | 0 |  | 0
Non-US [Member] | Significant Unobservable Inputs (Level 3) [Member] | Equity Funds [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [5],[8] | $ 0 |  | $ 0
[1] | Cash and cash equivalents are comprised of commercial paper, short-term bills and notes, and short-term investment funds, which are valued at quoted prices in active markets for similar securities.
[2] | Investment grade fixed income consists of debt obligations either issued by the US government or have a rating of BBB- / Baa or higher assigned by a major credit rating agency. These investments are valued based on unadjusted quoted market prices (Level 1), or based on quoted prices in inactive markets, or whose values are based on models, but the inputs to those models are observable either directly or indirectly (Level 2).
[3] | High yield fixed income consists primarily of debt obligations that have a rating of below BBB- / Baa or lower assigned by a major credit rating agency. These investments are valued based on unadjusted quoted market prices.
[4] | Alternative investments consists primarily of an investment in asset classes other than stocks, bonds, and cash. Alternative investments can include commodities, hedge funds, private equity, managed futures, and derivatives. These investments are valued based on unadjusted quoted market prices and can be redeemed on a bi-monthly basis.
[5] | Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been categorized in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position.
[6] | Real estate is investments in a real estate collective trust for purposes of total return. These investments are valued based on prices or valuation techniques that require inputs that are both unobservable and significant to the overall fair value measurement. These investments can be redeemed on a quarterly basis.
[7] | U.S. equity securities are comprised of investments in common stock of U.S. companies for total return purposes. These investments are valued by the trustee at closing prices from national exchanges on the valuation date.
[8] | International equity securities are comprised of investments in common stock of companies located outside of the U.S for total return purposes. These investments are valued by the trustee at closing prices from national exchanges on the valuation date, or the values are adjusted as a result of market movements following the close of local trading using inputs to models that are observable either directly or indirectly. The portion of these investments that are measured at fair value using the net asset value per share practical expedient (see note 4 below) can be redeemed on a monthly basis.

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 asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=112275985&loc=d3e4179-114921 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

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

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

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

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

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=country_US
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | srt_StatementGeographicalAxis=us-gaap_NonUsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |