Receivables Aging of Installment Receivables (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	$ 3,431	$ 5,612
0-30 Days Past Due	122	84
31-60 Days Past Due	44	42
61-90 Days Past Due	20	8
Greater than 90 Days Past Due	5,807	6,175
Total Installment Receivables Past Due	9,424	11,921
U.S.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	0	0
0-30 Days Past Due	0	0
31-60 Days Past Due	0	0
61-90 Days Past Due	0	0
Greater than 90 Days Past Due	5,499	6,116
Total Installment Receivables Past Due	5,499	6,116
CANADA
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	3,431	5,612
0-30 Days Past Due	122	84
31-60 Days Past Due	44	42
61-90 Days Past Due	20	8
Greater than 90 Days Past Due	308	59
Total Installment Receivables Past Due	$ 3,925	$ 5,805