Finance Receivables - Information regarding delinquency rates with respect to contracts and direct loans (Details 5) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Contracts
Financing Receivable, Recorded Investment, Past Due [Line Items]
Gross Balance Outstanding	$ 439,828	$ 499,549
Total	$ 60,506	$ 72,164
Total (in percentage)	13.76%	14.45%
Contracts | 31 - 60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Gross Balance Outstanding	$ 33,453	$ 35,184
Total (in percentage)	7.61%	7.04%
Contracts | 61 - 90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Gross Balance Outstanding	$ 14,039	$ 17,263
Total (in percentage)	3.19%	3.46%
Contracts | 91 - 120 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Gross Balance Outstanding	$ 7,893	$ 11,072
Total (in percentage)	1.79%	2.22%
Contracts | Over 120 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Gross Balance Outstanding	$ 5,121	$ 8,645
Total (in percentage)	1.16%	1.73%
Direct Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Gross Balance Outstanding	$ 10,566	$ 11,511
Total	$ 471	$ 562
Total (in percentage)	4.46%	4.88%
Direct Loans | 31 - 60 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Gross Balance Outstanding	$ 254	$ 282
Total (in percentage)	2.41%	2.45%
Direct Loans | 61 - 90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Gross Balance Outstanding	$ 102	$ 155
Total (in percentage)	0.97%	1.34%
Direct Loans | 91 - 120 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Gross Balance Outstanding	$ 32	$ 61
Total (in percentage)	0.30%	0.53%
Direct Loans | Over 120 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Gross Balance Outstanding	$ 83	$ 64
Total (in percentage)	0.78%	0.56%