Significant Concentrations and Risks (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Customer A [Member]
Sales to major customers
Sales to major customers , Amount	$ 11,738		$ 38,024	$ 52,844
Sales to major customers , Percentage	13.00%		13.00%	14.00%
Customer B [Member]
Sales to major customers
Sales to major customers , Amount	$ 9,694	$ 40,695	$ 29,168
Sales to major customers , Percentage	10.00%	21.00%	10.00%