Segment Information and Foreign Operations (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014 Segment	Mar. 31, 2013	Dec. 31, 2013
Segment Information [Abstract]
Number of operating segments	1
Net revenues reported for products shipped to customers in corresponding geographic region [Abstract]
Net revenue	$ 19,345	$ 22,380
Long-lived assets by geographic region [Abstract]
Long-lived assets	36,179		37,621
Major Customer One [Member]
Revenue, Major Customer [Line Items]
Number of customers representing significant revenue	0	0
Number of customers who accounted for 10% or more share in trade accounts receivable	1
Percentage of trade accounts receivable accounted by one customer (in hundredths)			20.00%
Top Five Major Customers [Member]
Revenue, Major Customer [Line Items]
Percentage of revenue generated by major customers (in hundredths)	39.00%	34.00%
Number of major customers	5	5
Europe (primarily Germany) [Member]
Net revenues reported for products shipped to customers in corresponding geographic region [Abstract]
Net revenue	6,583	4,689
China [Member]
Net revenues reported for products shipped to customers in corresponding geographic region [Abstract]
Net revenue	4,165	6,029
Long-lived assets by geographic region [Abstract]
Long-lived assets	36,000		37,417
Asia Pacific (excluding China, Japan and Taiwan) [Member]
Net revenues reported for products shipped to customers in corresponding geographic region [Abstract]
Net revenue	2,389	2,132
Taiwan [Member]
Net revenues reported for products shipped to customers in corresponding geographic region [Abstract]
Net revenue	2,115	3,779
Japan [Member]
Net revenues reported for products shipped to customers in corresponding geographic region [Abstract]
Net revenue	2,313	2,282
North America (primarily the United States) [Member]
Net revenues reported for products shipped to customers in corresponding geographic region [Abstract]
Net revenue	1,780	3,469
Long-lived assets by geographic region [Abstract]
Long-lived assets	$ 179		$ 204