Related Party Transactions - Shared Services Agreement with DriveTime (Details) - DriveTime Automotive Group, Inc. - Related parties - Shared Services Agreement with DriveTime - USD ($) $ in Millions	1 Months Ended	3 Months Ended	6 Months Ended
Feb. 28, 2021	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Related Party Transaction [Line Items]
Number of allowable days prior to contract termination with written notice	30 days
Number of allowable days prior to contract termination with written notice from service provider	90 days
Payments to acquire GAP waiver insurance policy (less than)		$ 1	$ 1	$ 1	$ 1

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.

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