| Business Acquisitions and Dispositions - Revenues and Other Activities Associated with Disposed Dealerships That Remain in Continuing Operations (Details) - Disposed dealerships that remain in continuing operations - USD ($) $ in Thousands | 12 Months Ended | ||
|---|---|---|---|
| Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | |
| Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] | |||
| Income (loss) from operations before taxes and items below | $ (2,200) | $ (2,600) | $ 2,700 | 
| Gain (loss) on disposal of dealerships (1) | 2,300 | 3,100 | 74,800 | 
| Discontinued Operation Lease Exit Accrual Adjustments And Charges | 400 | 0 | 200 | 
| Income (loss) before taxes | 500 | 500 | 77,700 | 
| Total revenues | $ 25,500 | $ 52,100 | $ 419,500 | 
| X | ||||||||||
| 
- Definition Discontinued operation lease exit accrual adjustments and charges. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Disposal group not discontinued operation income loss before income tax. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Disposal group not discontinued operation operating income loss. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Disposal group not discontinued operation revenue. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Amount before tax of gain (loss) recognized on the sale or disposal of a disposal group. Excludes discontinued operations. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
 | 
| X | ||||||||||
| 
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
 | 
| X | ||||||||||
| 
- Details 
 |