Receivables - Installment Receivables by Class (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Total Installment Receivables    
Non-impaired installment receivables with no related allowance recorded $ 818 $ 946
Impaired installment receivables with a related allowance recorded 3,894 3,681
Total installment receivables 4,712 4,627
Unpaid Principal Balance    
Non-impaired installment receivables with no related allowance recorded 778 904
Impaired installment receivables with a related allowance recorded 3,894 3,681
Total installment receivables 4,672 4,585
Related Allowance for Doubtful Accounts    
Impaired installment receivables with a related allowance recorded 2,838 2,792
Interest Income Recognized    
Non-impaired installment receivables with no related allowance recorded 65 52
Impaired installment receivables with a related allowance recorded 0 0
Total installment receivables 65 52
U.S.    
Total Installment Receivables    
Impaired installment receivables with a related allowance recorded 3,762 3,618
Unpaid Principal Balance    
Impaired installment receivables with a related allowance recorded 3,762 3,618
Related Allowance for Doubtful Accounts    
Impaired installment receivables with a related allowance recorded 2,706 2,729
Interest Income Recognized    
Impaired installment receivables with a related allowance recorded 0 0
CANADA    
Total Installment Receivables    
Non-impaired installment receivables with no related allowance recorded 818 946
Impaired installment receivables with a related allowance recorded 132 63
Total installment receivables 950 1,009
Unpaid Principal Balance    
Non-impaired installment receivables with no related allowance recorded 778 904
Impaired installment receivables with a related allowance recorded 132 63
Total installment receivables 910 967
Related Allowance for Doubtful Accounts    
Impaired installment receivables with a related allowance recorded 132 63
Interest Income Recognized    
Non-impaired installment receivables with no related allowance recorded 65 52
Impaired installment receivables with a related allowance recorded 0 0
Total installment receivables $ 65 $ 52