Description of Business (Percentage of Consumer Loans Assigned Based on Unit Volumes) (Details)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014
Description Of Business [Line Items]
Financing Receivable, Credit Quality, Additional Information	0.967				0.963
Portfolio Program [Member]
Description Of Business [Line Items]
Percentage of new consumer loans	88.60%	89.00%	90.50%	91.40%	91.70%
Purchase Program [Member]
Description Of Business [Line Items]
Percentage of new consumer loans	11.40%	11.00%	9.50%	8.60%	8.30%