Finance Receivables - Assessment of credit quality by creditworthiness (Details 3) - Finance receivables - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Contracts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 478,397,403	$ 431,877,085
Chapter 13 bankrupt accounts	4,340,698	3,872,186
Finance receivables, gross contract	482,738,101	435,749,271
Contracts | Performing accounts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	467,285,487	422,592,527
Contracts | Non-performing accounts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	11,111,916	9,284,558
Direct Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	12,032,334	11,680,909
Chapter 13 bankrupt accounts	38,091	26,774
Finance receivables, gross contract	12,070,425	11,707,683
Direct Loans | Performing accounts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	11,931,941	11,575,091
Direct Loans | Non-performing accounts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 100,393	$ 105,818