XML 77 R66.htm IDEA: XBRL DOCUMENT
v3.25.3

Financial Instruments and Fair Value Measurements (Narrative) (Details) $ in Millions | 3 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | ---
Sep. 30, 2025 USD ($) | Jun. 30, 2025 USD ($) store | Sep. 30, 2024 USD ($) | Sep. 30, 2025 USD ($) | Sep. 30, 2024 USD ($) | Apr. 30, 2025 USD ($) | Dec. 31, 2024 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |
Goodwill impairment | $ 0.0 |  | $ 0.0 | $ 65.3 | $ 0.0 |  |
Franchise rights impairment, number of stores | store |  | 9 |  |  |  |  |
Franchise rights impairment | 0.0 |  | 0.0 | 71.7 | 0.0 |  |
Reporting Unit, Other |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |
Goodwill impairment |  |  |  | 65.3 |  |  |
Fair Value, Nonrecurring [Member] |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |
Goodwill impairment |  |  |  | 65.3 | 0.0 |  |
Fair Value, Nonrecurring [Member] | Reporting Unit, Mobile Service |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |
Goodwill impairment |  | $ 65.3 |  |  |  |  |
Franchise Rights | Fair Value, Nonrecurring [Member] |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |
Franchise rights impairment |  | $ 71.7 |  | 71.7 | 0.0 |  |
Franchise Rights | Fair Value, Nonrecurring [Member] | Level 3 |  |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |  |  |  |  |
Franchise rights | 42.7 |  | $ 0.0 | 42.7 | $ 0.0 |  |
Franchise Rights | Fair Value, Nonrecurring [Member] | Level 3 | Valuation Technique, Discounted Cash Flow [Member] |  |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |  |  |  |  |
Franchise rights |  |  |  |  |  | $ 42.7 |
Franchise Rights | Fair Value, Nonrecurring [Member] | Level 3 | Measurement Input, Long-Term Revenue Growth Rate [Member] | Valuation Technique, Discounted Cash Flow [Member] |  |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |  |  |  |  |
Franchise Rights, Measurement Input |  |  |  |  |  | 0.020 |
Franchise Rights | Fair Value, Nonrecurring [Member] | Arithmetic Average [Member] | Level 3 | Measurement Input, Weighted Average Cost of Capital [Member] | Valuation Technique, Discounted Cash Flow [Member] |  |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |  |  |  |  |
Franchise Rights, Measurement Input |  |  |  |  |  | 0.090 |
Franchise Rights | Fair Value, Nonrecurring [Member] | Arithmetic Average [Member] | Level 3 | Measurement Input, Discount Rate [Member] | Valuation Technique, Discounted Cash Flow [Member] |  |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |  |  |  |  |
Franchise Rights, Measurement Input |  |  |  |  |  | 0.104 |
Franchise Rights | Fair Value, Nonrecurring [Member] | Arithmetic Average [Member] | Level 3 | Measurement Input, Long-term Pretax Loss Margin [Member] | Valuation Technique, Discounted Cash Flow [Member] |  |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |  |  |  |  |
Franchise Rights, Measurement Input |  |  |  |  |  | 0.024 |
Franchise Rights | Fair Value, Nonrecurring [Member] | Arithmetic Average [Member] | Level 3 | Measurement Input, Contributory Asset Charges [Member] | Valuation Technique, Discounted Cash Flow [Member] |  |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |  |  |  |  |
Franchise Rights, Measurement Input |  |  |  |  |  | 0.062 |
Franchise Rights | Fair Value, Nonrecurring [Member] | Minimum | Level 3 | Measurement Input, Weighted Average Cost of Capital [Member] | Valuation Technique, Discounted Cash Flow [Member] |  |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |  |  |  |  |
Franchise Rights, Measurement Input |  |  |  |  |  | 0.089 |
Franchise Rights | Fair Value, Nonrecurring [Member] | Minimum | Level 3 | Measurement Input, Discount Rate [Member] | Valuation Technique, Discounted Cash Flow [Member] |  |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |  |  |  |  |
Franchise Rights, Measurement Input |  |  |  |  |  | 0.096 |
Franchise Rights | Fair Value, Nonrecurring [Member] | Minimum | Level 3 | Measurement Input, Long-term Pretax Loss Margin [Member] | Valuation Technique, Discounted Cash Flow [Member] |  |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |  |  |  |  |
Franchise Rights, Measurement Input |  |  |  |  |  | 0.000 |
Franchise Rights | Fair Value, Nonrecurring [Member] | Minimum | Level 3 | Measurement Input, Contributory Asset Charges [Member] | Valuation Technique, Discounted Cash Flow [Member] |  |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |  |  |  |  |
Franchise Rights, Measurement Input |  |  |  |  |  | 0.051 |
Franchise Rights | Fair Value, Nonrecurring [Member] | Maximum | Level 3 | Measurement Input, Weighted Average Cost of Capital [Member] | Valuation Technique, Discounted Cash Flow [Member] |  |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |  |  |  |  |
Franchise Rights, Measurement Input |  |  |  |  |  | 0.091 |
Franchise Rights | Fair Value, Nonrecurring [Member] | Maximum | Level 3 | Measurement Input, Discount Rate [Member] | Valuation Technique, Discounted Cash Flow [Member] |  |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |  |  |  |  |
Franchise Rights, Measurement Input |  |  |  |  |  | 0.113 |
Franchise Rights | Fair Value, Nonrecurring [Member] | Maximum | Level 3 | Measurement Input, Long-term Pretax Loss Margin [Member] | Valuation Technique, Discounted Cash Flow [Member] |  |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |  |  |  |  |
Franchise Rights, Measurement Input |  |  |  |  |  | 0.059 |
Franchise Rights | Fair Value, Nonrecurring [Member] | Maximum | Level 3 | Measurement Input, Contributory Asset Charges [Member] | Valuation Technique, Discounted Cash Flow [Member] |  |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |  |  |  |  |
Franchise Rights, Measurement Input |  |  |  |  |  | 0.084 |
Carrying value | Continuing Operations |  |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |
Assets held for sale | $ 63.2 |  |  | $ 63.2 |  |  | $ 23.6

X
- Definition Number of stores with franchise rights carrying values that exceeded their fair values in the quantitative impairment tests. + References No definition available. + Details
Name: | an_FranchiseRightsImpairmentNumberOfStores
Namespace Prefix: | an_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Value of input used to measure franchise rights. + References No definition available. + Details
Name: | an_FranchiseRightsMeasurementInput
Namespace Prefix: | an_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount classified as assets attributable to disposal group held for sale or disposed of, expected to be disposed of within one year or the normal operating cycle, if longer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 10 -SubTopic 20 -Topic 205 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483475/205-20-45-10 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483499/205-20-50-7 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5C -Subparagraph (a)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483499/205-20-50-5C Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 360 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 9 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482130/360-10-45-9 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5B -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483499/205-20-50-5B Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 360 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482099/360-10-50-3 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483475/205-20-45-11 + Details
Name: | us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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 Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 100 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-100 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-3 + Details
Name: | us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_FairValueInputsQuantitativeInformationAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of impairment loss from asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -SubTopic 10 -Topic 230 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-28 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 24 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482548/350-20-55-24 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482573/350-20-50-2 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482573/350-20-50-6 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 100 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-100 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482573/350-20-50-1 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482598/350-20-45-2 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 805 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479581/805-30-50-4 + Details
Name: | us-gaap_GoodwillImpairmentLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of impairment loss resulting from write-down of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482686/350-30-45-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482665/350-30-50-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482665/350-30-50-3 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-28 + Details
Name: | us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Fair value portion of assets, excluding financial assets and goodwill, that lack physical substance, having a projected indefinite period of benefit. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-13 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2E -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2E + Details
Name: | us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwillFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_ReportingUnitAxis=an_ReportingUnitOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsNonrecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ReportingUnitAxis=an_ReportingUnitMobileServiceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_FranchiseRightsMember
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: | us-gaap_ValuationTechniqueAxis=us-gaap_ValuationTechniqueDiscountedCashFlowMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputLongTermRevenueGrowthRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_ArithmeticAverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=an_MeasurementInputWeightedAverageCostOfCapitalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputDiscountRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=an_MeasurementInputLongTermPretaxLossMarginMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=an_MeasurementInputContributoryAssetChargesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementOperatingActivitiesSegmentAxis=us-gaap_SegmentContinuingOperationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |