Long Term Debt - Schedule of Securitization Debt of Consolidated VIEs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Initial Principal		$ 93,730
Outstanding Principal		82,556
Fair Value		$ 79,829
United Auto Credit 2021-1-C
Debt Instrument [Line Items]
Final Scheduled Payment Date		Jun. 10, 2026
Initial Principal		$ 29,640
Contractual Interest Rate		0.84%
Outstanding Principal		$ 18,466
Fair Value		$ 18,322
United Auto Credit 2021-1-D
Debt Instrument [Line Items]
Final Scheduled Payment Date	Jun. 10, 2026	Jun. 10, 2026
Initial Principal	$ 29,380	$ 29,380
Contractual Interest Rate	1.14%	1.14%
Outstanding Principal	$ 3,246	$ 29,380
Fair Value	$ 3,235	$ 28,481
United Auto Credit 2021-1-E
Debt Instrument [Line Items]
Final Scheduled Payment Date	Jun. 10, 2026	Jun. 10, 2026
Initial Principal	$ 20,800	$ 20,800
Contractual Interest Rate	2.58%	2.58%
Outstanding Principal	$ 20,800	$ 20,800
Fair Value	$ 20,540	$ 19,685
United Auto Credit 2021-1-F
Debt Instrument [Line Items]
Final Scheduled Payment Date	Sep. 10, 2027	Sep. 10, 2027
Initial Principal	$ 13,910	$ 13,910
Contractual Interest Rate	4.30%	4.30%
Outstanding Principal	$ 13,910	$ 13,910
Fair Value	$ 13,644	$ 13,341
United Auto Credit 2022-2-B
Debt Instrument [Line Items]
Final Scheduled Payment Date	Dec. 10, 2025
Initial Principal	$ 30,324
Contractual Interest Rate	5.41%
Outstanding Principal	$ 28,786
Fair Value	$ 28,745
United Auto Credit 2022-2-C
Debt Instrument [Line Items]
Final Scheduled Payment Date	May 10, 2027
Initial Principal	$ 26,533
Contractual Interest Rate	5.81%
Outstanding Principal	$ 26,533
Fair Value	$ 26,331
United Auto Credit 2022-2-D
Debt Instrument [Line Items]
Final Scheduled Payment Date	Jan. 10, 2028
Initial Principal	$ 32,889
Contractual Interest Rate	6.84%
Outstanding Principal	$ 32,889
Fair Value	$ 32,642
United Auto Credit 2022-2-E
Debt Instrument [Line Items]
Final Scheduled Payment Date	Apr. 10, 2029
Initial Principal	$ 33,440
Contractual Interest Rate	10.00%
Outstanding Principal	$ 33,440
Fair Value	$ 29,691
United Auto Credit 2023-1-A
Debt Instrument [Line Items]
Final Scheduled Payment Date	Jul. 10, 2025
Initial Principal	$ 118,598
Contractual Interest Rate	5.57%
Outstanding Principal	$ 15,089
Fair Value	$ 15,083
United Auto Credit 2023-1-B
Debt Instrument [Line Items]
Final Scheduled Payment Date	Jul. 10, 2028
Initial Principal	$ 51,157
Contractual Interest Rate	5.91%
Outstanding Principal	$ 51,157
Fair Value	$ 51,019
United Auto Credit 2023-1-C
Debt Instrument [Line Items]
Final Scheduled Payment Date	Jul. 10, 2028
Initial Principal	$ 33,326
Contractual Interest Rate	6.28%
Outstanding Principal	$ 33,326
Fair Value	$ 33,199
United Auto Credit 2023-1-D
Debt Instrument [Line Items]
Final Scheduled Payment Date	Jul. 10, 2028
Initial Principal	$ 35,653
Contractual Interest Rate	8.00%
Outstanding Principal	$ 35,653
Fair Value	$ 36,152
United Auto Credit 2023-1-E
Debt Instrument [Line Items]
Final Scheduled Payment Date	Sep. 10, 2029
Initial Principal	$ 23,256
Contractual Interest Rate	10.98%
Outstanding Principal	$ 23,256
Fair Value	23,814
Total Rated Notes
Debt Instrument [Line Items]
Initial Principal	449,266
Outstanding Principal	318,085
Fair Value	$ 314,095