4. Trade Receivables, net (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Valuation and Qualifying Accounts Disclosure [Line Items]
Non-EPTA trade receivables	$ 444	$ 432
Conforming EPTAs	2,316	3,945
Gross trade receivables	3,224	4,960
Less allowance for doubtful accounts	(1,028)	(1,522)
Trade receivables, net	2,196	3,438
Current trade receivables, net	1,937	3,043
Long-term trade receivables, net	259	395
Trade receivables, net	2,196	3,438
Non-Conforming EPTAs [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
1 - 30 days	237	341
31 - 60 days	145	163
61 - 90 days	$ 82	$ 79