Basis and Summary of Significant Accounting Policies - Credit Quality Indicators (Details)	Mar. 31, 2020	Dec. 31, 2019
600 or Less
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, percentage of loan portfolio per FICO Score	7.60%	6.70%
Between 600 and 700
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, percentage of loan portfolio per FICO Score	79.70%	80.10%
700 or Greater
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, percentage of loan portfolio per FICO Score	12.70%	13.20%