XML 98 R80.htm IDEA: XBRL DOCUMENT
v3.20.4

Commitments and Contingencies - Summary of Lease Exit Accruals (Details) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2018 USD ($)
Commitments and Contingencies Disclosure [Abstract] |
Lease exit expense | $ 1,400

X
- Definition Lease exit expense. + References No definition available. + Details
Name: | sah_LeaseExitExpense
Namespace Prefix: | sah_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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