Segment Reporting, Geographic Information, and Significant Customers (Details 1)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
United States of America [Member]
Summary of geographic revenue as percentage of total revenues by country
Revenue by countries, percentage	38.00%	40.00%	36.00%
Korea [Member]
Summary of geographic revenue as percentage of total revenues by country
Revenue by countries, percentage	36.00%	37.00%	35.00%