Description of Business (Percentage of Consumer Loans Assigned Based on Unit Volumes) (Details)	3 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015
Portfolio Program [Member]
Description Of Business [Line Items]
Percentage of new consumer loans	76.20%	77.80%	82.40%	85.70%	87.30%	87.70%	88.60%
Purchase Program [Member]
Description Of Business [Line Items]
Percentage of new consumer loans	23.80%	22.20%	17.60%	14.30%	12.70%	12.30%	11.40%