Annual report pursuant to Section 13 and 15(d)

Segment Information - Net Sales by Market (Details)

v3.8.0.1
Segment Information - Net Sales by Market (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Segment Reporting Information [Line Items]      
Net sales $ 197,563 $ 287,728 $ 264,860
United States      
Segment Reporting Information [Line Items]      
Net sales 3,348 4,100 3,246
Canada      
Segment Reporting Information [Line Items]      
Net sales 1,938 1,809 2,746
PERU      
Segment Reporting Information [Line Items]      
Net sales 508 0 0
Hong Kong      
Segment Reporting Information [Line Items]      
Net sales 174,926 263,482 245,737
China      
Segment Reporting Information [Line Items]      
Net sales 7,282 9,086 4,425
Taiwan      
Segment Reporting Information [Line Items]      
Net sales 5,591 6,213 5,965
South Korea      
Segment Reporting Information [Line Items]      
Net sales 466 691 1,129
Commonwealth of Independent States (Russia, Kazakhstan and Ukraine)      
Segment Reporting Information [Line Items]      
Net sales 913 858 1,139
Europe [Member]      
Segment Reporting Information [Line Items]      
Net sales 2,278 1,234 382
Other foreign countries      
Segment Reporting Information [Line Items]      
Net sales $ 313 $ 255 $ 91