Receivables - Aging of Installment Receivables (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 976	$ 1,338
0-30 Days Past Due	15	7
31-60 Days Past Due	2	0
61-90 Days Past Due	0	0
90 Days Past Due	6,816	7,574
Total	7,809	8,919
U.S.
Financing Receivable, Recorded Investment, Past Due [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
90 Days Past Due	6,735	7,464
Total	6,735	7,464
CANADA
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	976	1,338
0-30 Days Past Due	15	7
31-60 Days Past Due	2	0
61-90 Days Past Due	0	0
90 Days Past Due	81	110
Total	$ 1,074	$ 1,455