Concentrations and Risks (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues earned in geographic areas
Revenues	$ 113,326	$ 125,480	$ 278,598	$ 306,806
Wholesale Business [Member]
Revenues earned in geographic areas
Revenues	81,737	85,683	147,090	149,753
Retail Business [Member]
Revenues earned in geographic areas
Revenues	31,589	39,797	131,508	157,053
The People’s Republic of China [Member]
Revenues earned in geographic areas
Revenues	23,241	25,853	40,486	39,195
Hong Kong China [Member]
Revenues earned in geographic areas
Revenues	14,574	18,427	22,291	30,982
Germany [Member]
Revenues earned in geographic areas
Revenues	981	2,750	2,708	5,515
United Kingdom
Revenues earned in geographic areas
Revenues	10,555	8,254	13,393	13,353
Europe-Other [Member]
Revenues earned in geographic areas
Revenues	12,523	19,707	21,977	29,993
Japan [Member]
Revenues earned in geographic areas
Revenues	10,056	2,371	16,304	6,689
United States [Member]
Revenues earned in geographic areas
Revenues	$ 9,807	$ 8,321	$ 29,931	$ 24,026