XML 87 R90.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Commitments and Contingencies - Summary of Lease Exit Accruals (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2014
Commitments And Contingencies Disclosure [Abstract] |
Component of lease exit expense in interest expense, other, net | $ 0.2 sah_LeaseExitExpenseInterestOther
Component of lease exit expense in selling, general and administrative expenses | 0.3 sah_LeaseExitExpenseSellingGeneralAndAdministrative
Component of lease exit expense in income (loss) from operations and the sale of dealerships | 0.2 sah_LeaseExitExpenseDiscontinuedOperations
Component of lease exit payments in selling, general and administrative expenses | 0.8 sah_LeaseExitPaymentSellingGeneralAndAdministrative
Component of lease exit payments in income (loss) from operations and the sale of dealerships | $ 6.2 sah_LeaseExitPaymentDiscontinuedOperations

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

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

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

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

X
- Definition Lease exit payment selling general and administrative. + References No definition available. + Details
Name: | sah_LeaseExitPaymentSellingGeneralAndAdministrative
Namespace Prefix: | sah_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_CommitmentsAndContingenciesDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration