Concentrations and Risks (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Revenues earned in geographic areas
Total	$ 91,693	$ 97,903
The People's Republic of China [Member]
Revenues earned in geographic areas
Total	14,798	18,934
Germany [Member]
Revenues earned in geographic areas
Total	1,453	4,487
United Kingdom [Member]
Revenues earned in geographic areas
Total	2,588	3,152
Europe-Other [Member]
Revenues earned in geographic areas
Total	5,454	1,802
Japan [Member]
Revenues earned in geographic areas
Total	4,813	2,930
United States [Member]
Revenues earned in geographic areas
Total	3,444	1,969
Total wholesale business [Member]
Revenues earned in geographic areas
Total	32,550	33,274
Retail Business [Member]
Revenues earned in geographic areas
Total	$ 59,143	$ 64,629