Receivables Installment Receivables by Class (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Installment Receivables	$ 6,570	$ 6,488
Unpaid Principal Balance	6,508	6,417
Related Allowance for Doubtful Accounts	4,043	3,823
Interest Income Recognized	30	120
CANADA
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Installment Receivables	1,665	1,980
Unpaid Principal Balance	1,603	1,909
Related Allowance for Doubtful Accounts	211	458
Interest Income Recognized	30	120
Impaired Installment Receivables with Related Allowance [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Installment Receivables	5,116	4,966
Unpaid Principal Balance	5,116	4,966
Related Allowance for Doubtful Accounts	4,043	3,823
Interest Income Recognized	0	0
Impaired Installment Receivables with Related Allowance [Member] | U.S.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Installment Receivables	4,905	4,508
Unpaid Principal Balance	4,905	4,508
Related Allowance for Doubtful Accounts	3,832	3,365
Interest Income Recognized	0	0
Impaired Installment Receivables with Related Allowance [Member] | CANADA
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Installment Receivables	211	458
Unpaid Principal Balance	211	458
Related Allowance for Doubtful Accounts	211	458
Interest Income Recognized	0	0
Installment Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Installment Receivables	1,454	1,522
Unpaid Principal Balance	1,392	1,451
Related Allowance for Doubtful Accounts	0	0
Interest Income Recognized	30	120
Installment Receivables [Member] | CANADA
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Installment Receivables	1,454	1,522
Unpaid Principal Balance	1,392	1,451
Related Allowance for Doubtful Accounts	0	0
Interest Income Recognized	$ 30	$ 120