| **GOODWILL AND OTHER INTANGIBLES (Finite-lived Intangibles) (Details) - USD ($) $ in Thousands** | Mar. 31, 2019 | Dec. 31, 2018 |
|--------------------------------------------------------------------------------------------------|---------------|---------------|
| **Finite-Lived Intangible Assets [Line Items]**                                                  |          |          |
| Net Carrying Amount                                                                              | $ 460,429     | $ 475,193     |
| Accumulated Amortization                                                                         | (331,510)     | (316,748)     |
| Dealer networks                                                                                  |          |          |
| **Finite-Lived Intangible Assets [Line Items]**                                                  |          |          |
| Net Carrying Amount                                                                              | 377,393       | 387,196       |
| Accumulated Amortization                                                                         | (202,607)     | (192,804)     |
| Chrysler relationship                                                                            |          |          |
| **Finite-Lived Intangible Assets [Line Items]**                                                  |          |          |
| Net Carrying Amount                                                                              | 61,250        | 65,000        |
| Accumulated Amortization                                                                         | (77,500)      | (73,750)      |
| Trade name                                                                                       |          |          |
| **Finite-Lived Intangible Assets [Line Items]**                                                  |          |          |
| Net Carrying Amount                                                                              | 14,400        | 14,700        |
| Accumulated Amortization                                                                         | (3,600)       | (3,300)       |
| Other intangibles                                                                                |          |          |
| **Finite-Lived Intangible Assets [Line Items]**                                                  |          |          |
| Net Carrying Amount                                                                              | 7,386         | 8,297         |
| Accumulated Amortization                                                                         | $ (47,803)    | $ (46,894)    |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.
+ References
Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275
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| 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.
+ References
No definition available.
+ Details**Name:**us-gaap_FiniteLivedIntangibleAssetsLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.
+ References
Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275
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| X                                                                                                                                                                   |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                                               |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                                    |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                                               |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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