Receivables (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Installment Receivables	$ 6,488	$ 11,921
Installment Receivables, Net of Unearned Interest	6,417	11,750
Allowance for doubtful accounts	(3,823)	(4,273)
Installment receivables, net	2,188	6,671
Installment receivables, net, long-term	406	806
Installment Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Installment Receivables, Current	4,982	8,990
Installment Receivables, Long-Term	1,506	2,931
Total Installment Receivables	6,488	11,921
Unearned Interest, Current	(71)	(171)
Unearned Interest, Noncurrent	0	0
Total Unearned Interest	(71)	(171)
Installment Receivables Net of Unearned Interest Current	4,911	8,819
Installment Receivables Net of Unearned Interest Noncurrent	1,506	2,931
Installment Receivables, Net of Unearned Interest	6,417	11,750
Allowance for doubtful accounts, current	(2,723)	(2,148)
Allowance for doubtful accounts, long-term	(1,100)	(2,125)
Allowance for doubtful accounts	(3,823)	(4,273)	(4,841)
Installment receivables, net	2,188	6,671
Installment receivables, net, long-term	406	806
Installment receivables, net	$ 2,594	$ 7,477