Receivables (Installment Receivables by Class) (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2018	Dec. 31, 2017
Total Installment Receivables
Non-Impaired installment receivables with no related allowance recorded	$ 889	$ 923
Impaired installment receivables with a related allowance recorded	3,005	3,568
Total installment receivables	3,894	4,491
Unpaid Principal Balance
Non-Impaired installment receivables with no related allowance recorded	857	885
Impaired installment receivables with a related allowance recorded	3,005	3,568
Total installment receivables	3,862	4,453
Non-Impaired Financing Receivable, Related Allowance	0	0
Related Allowance for Doubtful Accounts
Impaired installment receivables with a related allowance recorded	2,285	2,644
Interest Income Recognized
Non-Impaired installment receivables with no related allowance recorded	68	74
Impaired installment receivables with a related allowance recorded	0	0
Total installment receivables	68	74
U.S.
Total Installment Receivables
Impaired installment receivables with a related allowance recorded	3,005	3,566
Unpaid Principal Balance
Impaired installment receivables with a related allowance recorded	3,005	3,566
Related Allowance for Doubtful Accounts
Impaired installment receivables with a related allowance recorded	2,285	2,642
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	889	923
Impaired installment receivables with a related allowance recorded	0	2
Total installment receivables	889	925
Unpaid Principal Balance
Non-Impaired installment receivables with no related allowance recorded	857	885
Impaired installment receivables with a related allowance recorded	0	2
Total installment receivables	857	887
Non-Impaired Financing Receivable, Related Allowance	0	0
Related Allowance for Doubtful Accounts
Impaired installment receivables with a related allowance recorded	0	2
Interest Income Recognized
Non-Impaired installment receivables with no related allowance recorded	68	74
Impaired installment receivables with a related allowance recorded	0	0
Total installment receivables	$ 68	$ 74

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- Definition

Financing Receivable, Recorded Investment

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Financing Receivable, Unpaid Principal Balance

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Financing Receivable, with No Related Allowance, Interest Income, Accrual Method

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Financing Receivable, with No Related Allowance, Recorded Investment

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Financing Receivable, with No Related Allowance, Unpaid Principal Balance

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Impaired Financing Receivable, Related Allowance [Abstract]

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Non-Impaired Financing Receivable, Related Allowance

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Amount of allowance for credit losses related to recorded investment.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
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Amount of interest income, recognized on accrual basis, on financing receivables, for which there is a related allowance for credit losses and are recognized as impaired.

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-Publisher FASB
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Amount of investment in impaired financing receivables for which there is a related allowance for credit losses.

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-Publisher FASB
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Unpaid principal balance of impaired financing receivables for which there is a related allowance for credit losses.

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