VIEs (Off-balance Sheet Portfolio) (Details) - VIE, Not Primary Beneficiary - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Total serviced for other portfolio	$ 2,250,584	$ 2,408,205
Third party SCART serviced securitizations
Variable Interest Entity [Line Items]
Total serviced for other portfolio	484,413	0
Third party Chrysler Capital securitizations
Variable Interest Entity [Line Items]
Total serviced for other portfolio	127,108	259,197
SC
Variable Interest Entity [Line Items]
Total serviced for other portfolio	$ 1,639,063	$ 2,149,008