|**GOODWILL AND OTHER INTANGIBLES (Tables)**                            | 6 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
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|**Goodwill and Intangible Assets Disclosure [Abstract]**               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Summary of Goodwill                                                    | The following table presents the roll-forward of the Company's goodwill by its reporting units for the quarter ended June 30, 2022:(in thousands)AutoCBBC&ICRECIBSCTotalGoodwill at December 31, 2021$—$297,802$52,198$1,095,071$131,130$1,019,960$2,596,161Additions during the period————171,571—171,571Re-allocation of goodwill1,238,676(138,776)—(79,940)—(1,019,960)—Goodwill at June 30, 2022$1,238,676$159,026$52,198$1,015,131$302,701$—$2,767,732                                                                         
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|(in thousands)                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Goodwill at December 31, 2021                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
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|Additions during the period                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
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|Re-allocation of goodwill                                              |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Goodwill at June 30, 2022                                              |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Summary of Finite-Lived Intangible Assets                              | The following table details amounts related to the Company's intangible assets subject to amortization for the dates indicated.June 30, 2022December 31, 2021(in thousands)Net CarryingAmountAccumulatedAmortizationNet CarryingAmountAccumulatedAmortizationIntangibles subject to amortization:Dealer networks$272,208$(197,792)$283,958$(186,042)Stellantis  relationship13,815(124,935)20,000(118,750)Other intangibles68,864(54,366)35,121(48,541)Total intangibles subject to amortization$354,887$(377,093)$339,079$(353,333)
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|(in thousands)                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Intangibles subject to amortization:                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Dealer networks                                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Stellantis  relationship                                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Other intangibles                                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Total intangibles subject to amortization                              |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Summary of Finite-Lived Intangible Assets, Future Amortization Expense | The estimated aggregate amortization expense related to intangibles, excluding any impairment charges, for each of the five succeeding calendar years ending December 31 is:YearCalendar Year AmountRecorded To DateRemaining Amount To Record(in thousands)2022$45,711$23,034$22,677202343,204—43,204202439,085—39,085202534,685—34,685202632,512—32,512Thereafter182,724—182,724                                                                                                                                                  
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|Year                                                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
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|2022                                                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|2023                                                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|2024                                                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|2025                                                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|2026                                                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Thereafter                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     

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