Inventories and Deferred Costs of Goods Sold (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Raw materials	$ 1,524		$ 1,784
Work in process	2,086		2,103
Finished goods	1,356		1,429
Net inventory	4,966		5,316
Inventory Valuation Reserves	1,000		860
Deferred cost of goods sold	92		185
Inventory write-off	$ 0	$ 29