Sonic Automotive, Inc. Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements (Details Textual) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Fair Value Measurements (Textual) [Abstract]
Assets recorded at fair value	$ 28.3	$ 21.4
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Measurements (Textual) [Abstract]
Assets recorded at fair value	0	0
Liabilities recorded at fair value	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Measurements (Textual) [Abstract]
Assets recorded at fair value	0	0
Liabilities recorded at fair value	0	0
9.0% Senior Subordinated Notes due 2018 [Member]
Fair Value Measurements (Textual) [Abstract]
Stated Interest rate on debt agreement	9.00%
7.0% Senior Subordinated Notes due 2022 [Member]
Fair Value Measurements (Textual) [Abstract]
Stated Interest rate on debt agreement	7.00%
5.0% Convertible Senior Note due 2023 [Member]
Fair Value Measurements (Textual) [Abstract]
Stated Interest rate on debt agreement	5.00%
Cash flow swaps designated as hedges [Member]
Fair Value Measurements (Textual) [Abstract]
Amount included in other accrued liabilities	11.2	11.4
Amount included in other long-term liabilities	11.2	20.0
Cash flow swaps not designated as hedges [Member]
Fair Value Measurements (Textual) [Abstract]
Amount included in other accrued liabilities	0.7	0.7
Amount included in other long-term liabilities	$ 1.6	$ 2.2