Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt - Long-Term Debt (Detail)

v2.4.1.9
Long-Term Debt - Long-Term Debt (Detail) (USD $)
Mar. 31, 2015
Dec. 31, 2014
Debt Instrument [Line Items]    
Total debt $ 794,625,000us-gaap_DebtInstrumentCarryingAmount $ 773,412,000us-gaap_DebtInstrumentCarryingAmount
Less current maturities (38,237,000)us-gaap_LongTermDebtCurrent (30,802,000)us-gaap_LongTermDebtCurrent
Long-Term Debt 756,388,000us-gaap_LongTermDebtNoncurrent 742,610,000us-gaap_LongTermDebtNoncurrent
2014 Revolving Credit Facility [Member]    
Debt Instrument [Line Items]    
Total debt 0us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_LongtermDebtTypeAxis
= sah_TwoThousandFourteenRevolvingCreditFacilityMember
 
7.0% Senior Subordinated Notes Due 2022 [Member]    
Debt Instrument [Line Items]    
Total debt 200,000,000us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_LongtermDebtTypeAxis
= sah_SevenPercentSeniorSubordinateNoteDueTwoThousandTwentyTwoMember
200,000,000us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_LongtermDebtTypeAxis
= sah_SevenPercentSeniorSubordinateNoteDueTwoThousandTwentyTwoMember
5.0% Senior Subordinated Notes due 2023 [Member]    
Debt Instrument [Line Items]    
Total debt 300,000,000us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_LongtermDebtTypeAxis
= sah_FivePercentSeniorSubordinateNoteDueTwoThousandTwentyThreeMember
300,000,000us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_LongtermDebtTypeAxis
= sah_FivePercentSeniorSubordinateNoteDueTwoThousandTwentyThreeMember
Notes Payable to Finance Company [Member]    
Debt Instrument [Line Items]    
Total debt 3,496,000us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
4,367,000us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
Mortgage Loan at Fix Interest Rate [Member]    
Debt Instrument [Line Items]    
Total debt 145,732,000us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_LongtermDebtTypeAxis
= sah_MortgageLoanAtFixInterestRateMember
147,554,000us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_LongtermDebtTypeAxis
= sah_MortgageLoanAtFixInterestRateMember
Mortgage Loan at Variable Interest Rate [Member]    
Debt Instrument [Line Items]    
Total debt 142,305,000us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_LongtermDebtTypeAxis
= sah_MortgageLoanAtVariableInterestRateMember
118,368,000us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_LongtermDebtTypeAxis
= sah_MortgageLoanAtVariableInterestRateMember
Net Debt Discount and Premium [Member]    
Debt Instrument [Line Items]    
Total debt (1,724,000)us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_LongtermDebtTypeAxis
= sah_DebtAtDiscountAndPremiumMember
(1,761,000)us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_LongtermDebtTypeAxis
= sah_DebtAtDiscountAndPremiumMember
Other [Member]    
Debt Instrument [Line Items]    
Total debt $ 4,816,000us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_LongtermDebtTypeAxis
= sah_OtherDebtMember
$ 4,884,000us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_LongtermDebtTypeAxis
= sah_OtherDebtMember