Notes Receivable (Percentage Of Gross Notes Receivable Outstanding By FICO Score At Origination) (Details)	12 Months Ended
	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Percentage of gross notes receivable outstanding	100.00%
No Score [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Percentage of gross notes receivable outstanding	1.00%
Less Than 601 [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Percentage of gross notes receivable outstanding	3.00%
601-700 [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Percentage of gross notes receivable outstanding	37.00%
701+ [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Percentage of gross notes receivable outstanding	59.00%