Sonic Automotive, Inc. Annual report pursuant to Section 13 and 15(d)

Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans - Additional Information (Details)

Employee Benefit Plans - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) Plans Employer Members shares	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Sep. 30, 2023 USD ($)	Jun. 30, 2023 shares	Mar. 31, 2023 USD ($)	Jun. 30, 2022 shares	Jun. 30, 2021 shares	Jun. 30, 2020 shares	Jun. 30, 2017 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of active stock compensation plans \| Plans	2
Restricted stock shares \| shares	400,000
Number of employers obligated to make contribution under multiemployer plan \| Employer	160
Number of employee increase / (decrease) under multiemployer benefit percentage	(9.60%)	4.30%
Total contributions of multi employer Plan		5.00%
Multiemployer Plan, Increase in Employer Contribution, Business Combination, Percentage	2.00%
AI Pension Plan projected pension liability						$ 1,000,000
AI Pension Plan special financial assistance				$ 1,100,000
SERP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Members of senior management \| Members	13
Restricted stock units and restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Tax benefit recognized	$ 6,600	$ 5,600	$ 4,000
Restricted stock units and restricted stock awards \| Selling, general and administrative expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	23,300	20,500	15,000
Restricted stock units and restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense not yet recognized	$ 39,800
Total compensation cost related to non-vested options expected to be recognized over weighted average period	2 years 10 months 24 days
401(k) plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employer contribution	$ 13,200	$ 12,100	$ 10,400
2012 Formula Plan \| Class A common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized \| shares					600,000		500,000			300,000
2012 Plan \| Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock award vesting period	3 years
2012 Plan \| Restricted stock units \| Executive officers and other key associates
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock shares \| shares	412,000
2012 Plan \| Restricted stock awards \| Board of Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock shares \| shares	40,000
2012 Plan \| Class A common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized \| shares					8,000,000			6,000,000	4,000,000	2,000,000
2012 Formula Plan and 2004 Plan \| Class A common stock \| Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option expiration period	10 years
2012 Formula Plan and 2004 Plan \| Class A common stock \| Options \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock award vesting period	3 years
2012 Formula Plan and 2004 Plan \| Class A common stock \| Restricted stock awards and restricted stock units \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock award vesting period	1 year
2012 Formula Plan and 2004 Plan \| Class A common stock \| Restricted stock awards and restricted stock units \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock award vesting period	3 years