Description of Business (Percentage of Consumer Loans Assigned Based on Volumes) (Details)		3 Months Ended
		Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022
Portfolio Program [Member]
Description Of Business [Line Items]
Percentage of new consumer loans unit volume		78.20%	77.20%	74.80%	72.40%	72.10%
Percentage of new consumer loans dollar volume	[1]	76.60%	75.00%	71.70%	68.60%	68.10%
Purchase Program [Member]
Description Of Business [Line Items]
Percentage of new consumer loans unit volume		21.80%	22.80%	25.20%	27.60%	27.90%
Percentage of new consumer loans dollar volume	[1]	23.40%	25.00%	28.30%	31.40%	31.90%

[1] Represents advances paid to Dealers on Consumer Loans assigned under our Portfolio Program and one-time payments made to Dealers to purchase Consumer Loans assigned under our Purchase Program. Payments of Dealer Holdback (as defined below) and accelerated Dealer Holdback are not included.