Loan Loss Allowance and Credit Quality - Summary of Credit Risk Profile (Details)	Mar. 31, 2014	Dec. 31, 2013
FICO Band 540
Financing Receivable Recorded Investment [Line Items]
Retail Installment Contracts Held for Investment	27.00%	26.80%
Unsecured Consumer Loans	3.60%	6.30%
FICO Band 540-599
Financing Receivable Recorded Investment [Line Items]
Retail Installment Contracts Held for Investment	32.20%	31.80%
Unsecured Consumer Loans	27.70%	24.20%
FICO Band 600-659
Financing Receivable Recorded Investment [Line Items]
Retail Installment Contracts Held for Investment	26.20%	26.30%
Unsecured Consumer Loans	43.80%	39.40%
FICO Band 660
Financing Receivable Recorded Investment [Line Items]
Retail Installment Contracts Held for Investment	14.60%	15.10%
Unsecured Consumer Loans	24.90%	30.10%