Description Of Business (Percentage Of Consumer Loans Assigned Based On Unit and Dollar Volumes) (Details)		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Portfolio Program [Member]
Description Of Business [Line Items]
Percentage of new consumer loans in unit volume		64.10%	67.20%	69.70%
Percentage of new consumer loans in dollar volume	[1]	60.60%	64.30%	67.20%
Purchase Program [Member]
Description Of Business [Line Items]
Percentage of new consumer loans in unit volume		35.90%	32.80%	30.30%
Percentage of new consumer loans in dollar volume	[1]	39.40%	35.70%	32.80%

[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.