XML 60 R44.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Business Acquisitions and Dispositions - Additional Information (Details) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2018 USD ($) Dealerships Store Franchise | Dec. 31, 2017 USD ($) Dealerships | Dec. 31, 2016 USD ($) Store Dealerships
Business Acquisition [Line Items] |  |  |
Number of franchise dealerships opened | 1 |  |
Number of stores opened | Store | 3 |  |
Number of franchises disposed | 7 | 3 | 0
Cash generated from disposition | $ | $ 128,700 | $ 38,200 |
Number of franchises terminated | 1 |  |
Number of terminated stores | Store | 4 |  |
Number of dealerships held for sale | Franchise | 0 |  |
Pre-owned vehicle store |  |  |
Business Acquisition [Line Items] |  |  |
Business acquisition, consideration amount | $ |  | $ 76,600 |
Number of businesses acquired |  |  | 1
Operating locations and related real estate |  |  |
Business Acquisition [Line Items] |  |  |
Business acquisition, consideration amount | $ |  |  | $ 15,900
Operating locations | Store |  |  | 3

X
- Definition Held for sale dealerships number. + References No definition available. + Details
Name: | sah_HeldForSaleDealershipsNumber
Namespace Prefix: | sah_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of Franchise Dealerships Opened + References No definition available. + Details
Name: | sah_NumberOfFranchiseDealershipsOpened
Namespace Prefix: | sah_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of franchises disposed. + References No definition available. + Details
Name: | sah_NumberOfFranchisesDisposed
Namespace Prefix: | sah_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number Of Franchises Terminated + References No definition available. + Details
Name: | sah_NumberOfFranchisesTerminated
Namespace Prefix: | sah_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- References No definition available. + Details
Name: | sah_NumberOfOperatingLocations
Namespace Prefix: | sah_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number Of Stores Opened + References No definition available. + Details
Name: | sah_NumberOfStoresOpened
Namespace Prefix: | sah_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of Stores Terminated + References No definition available. + Details
Name: | sah_NumberOfStoresTerminated
Namespace Prefix: | sah_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Proceeds from dispositions of franchises. + References No definition available. + Details
Name: | sah_ProceedsFromDispositionsOfFranchises
Namespace Prefix: | sah_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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_BusinessAcquisitionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=109124213&loc=d3e6613-128477 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=109124213&loc=d3e6578-128477 + Details
Name: | us-gaap_BusinessCombinationConsiderationTransferred1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The number of businesses acquired by the entity during the period. + References No definition available. + Details
Name: | us-gaap_NumberOfBusinessesAcquired
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=sah_StandAlonePreOwnedVehicleStoreMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=sah_StandAlonePreOwnedVehicleStoreAndRelatedRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |