Long-Term Debt and Commercial Paper (Restrictions And Covenants) (Details) - Jun. 30, 2015 - Credit Facility Due 2019 [Member] - USD ($) $ in Millions	Total
Debt Instrument [Line Items]
Capitalization ratio, requirement	70.00%
Leverage ratio, requirement	3.75
The maximum threshold of letters of credit excluded from the leverage ratio calculation	$ 150.0
Capitalization ratio calculation, additions to shareholders' equity	$ 1,530.0

Under the credit agreement, the amount added to shareholders' equity in the calculation of the capitalization ratio.

No definition available.

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Namespace Prefix:	an_
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Balance Type:	credit
Period Type:	instant

- Definition

Under the terms of the credit agreement, the maximum amount of letters of credit excluded from the definition of debt used in the calculation of the leverage ratio.

+ References

No definition available.

+ Details

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- Definition

The maximum capitalization ratio required under the company's credit agreement, which is a contractually defined amount principally reflecting vehicle floorplan payable and non-vehicle debt divided by the company's total capitalization including vehicle floorplan payable and certain adjustments.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

The maximum leverage ratio required under the company's credit agreement, which is a contractually defined amount principally reflecting non-vehicle debt divided by a contractually defined measure of earnings with certain adjustments.

+ References

No definition available.

+ Details

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- 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

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Period Type:	duration

- Details

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