| Business Acquisitions and Dispositions - Results Associated with Disposed Dealerships That Remain in Continued Operations (Detail) (USD $) In Thousands, unless otherwise specified | 3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
| Jun. 30, 2014 | Jun. 30, 2013 | Jun. 30, 2014 | Jun. 30, 2013 | |
| Business Combinations [Abstract] | ||||
| Income (loss) from operations | $ (61) | $ (467) | $ (507) | $ (1,175) | 
| Gain (loss) on disposal | 7,260 | 7,624 | ||
| Pre-tax income (loss) | 7,199 | (467) | 7,117 | (1,175) | 
| Total revenues | $ 21,870 | $ 23,628 | $ 42,485 | $ 49,612 | 
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- Definition Disposal Group Not Discontinued Operation Income Loss Before Income Tax No definition available. 
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- Definition Disposal Group Not Discontinued Operation Operating Income Loss No definition available. 
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- Definition Disposal Group Not Discontinued Operation Revenue No definition available. 
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- Details 
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- Definition The gain (loss) resulting from the sale of a disposal group that is not a discontinued operation. It is included in income from continuing operations before income taxes in the income statement. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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