XML 66 R49.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Description of Business and Summary of Significant Accounting Policies (Revenue Recognition, Advertising) (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Advertising [Abstract] |  |  |  |
Advertising expense, net | $ 196.7 | $ 188.5 | $ 164.9 |
Manufacturer advertising reimbursements | 58.5 | 56.4 | 47.1 |
Chargeback Reserves [Member] |  |  |  |
Revenue Recognition [Abstract] |  |  |  |
Chargeback liabilities | $ 116.8 | $ 97.3 | $ 84.9 | $ 67.6

X
- Definition Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 720 -SubTopic 35 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6420018&loc=d3e36677-107848 + Details
Name: | us-gaap_AdvertisingExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Total amount received by an entity from a vendor under a cooperative advertising arrangement that has been offset against advertising expense. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 605 -SubTopic 50 -Section 45 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=68069731&loc=d3e63872-111659 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cooperative Advertising -URI http://asc.fasb.org/extlink&oid=51574790 + Details
Name: | us-gaap_CooperativeAdvertisingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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

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

X
- Definition Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690 + Details
Name: | us-gaap_ValuationAllowancesAndReservesBalance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_ValuationAllowancesAndReservesTypeAxis=an_ChargebacksReservesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |