Finance Receivables - Assessment of credit quality by creditworthiness (Details 4) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Contracts
Financing Receivable, Recorded Investment [Line Items]
Total	$ 499,549	$ 478,397
Chapter 13 bankruptcy accounts	4,220	4,341
Finance receivables, gross contract	503,769	482,738
Contracts | Performing accounts
Financing Receivable, Recorded Investment [Line Items]
Total	462,569	467,285
Contracts | Non-performing accounts
Financing Receivable, Recorded Investment [Line Items]
Total	36,980	11,112
Direct Loan Portfolio
Financing Receivable, Recorded Investment [Line Items]
Total	11,511	12,032
Chapter 13 bankruptcy accounts	36	38
Finance receivables, gross contract	11,547	12,070
Direct Loan Portfolio | Performing accounts
Financing Receivable, Recorded Investment [Line Items]
Total	11,231	11,932
Direct Loan Portfolio | Non-performing accounts
Financing Receivable, Recorded Investment [Line Items]
Total	$ 280	$ 100