XML 21 R57.htm IDEA: XBRL DOCUMENT
v3.2.0.727

Financial Instruments And Fair Value Measurements (Summary Of Carrying Values And Fair Values Of Fixed Rate Debt) (Details) - USD ($) $ in Millions | Jun. 30, 2015 | Dec. 31, 2014
--- | --- | ---
Carrying Value [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Fixed rate debt | $ 1,030.1 | $ 1,018.4
Fair Value [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Fixed rate debt | $ 1,118.4 | $ 1,109.9

X
- Definition The total amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a fixed rate. This element is used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. + References No definition available. + Details
Name: | an_FixedRateDebtFairValue
Namespace Prefix: | an_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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 No definition available. + Details
Name: | us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

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