Consolidated Statements of Operations - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Income Statement [Abstract]        
Net sales $ 192,296 $ 154,382 $ 507,507 $ 481,282
Cost of sales 153,157 119,683 397,370 376,320
Gross profit 39,139 34,699 110,137 104,962
Operating expenses        
Selling, general and administrative expenses 20,082 22,107 65,982 75,725
Research and development expenses 18,439 20,450 54,432 64,541
Restructuring gain     (7,785)  
Total operating expenses 38,521 42,557 112,629 140,266
Operating income (loss) 618 (7,858) (2,492) (35,304)
Interest expense (4,055) (4,075) (12,185) (12,187)
Foreign currency gain (loss), net 33,174 (44,139) 34,268 (59,611)
Other income, net 887 256 2,429 1,162
Income (loss) before income taxes 30,624 (55,816) 22,020 (105,940)
Income tax expenses 758 1,250 1,845 1,781
Net income (loss) $ 29,866 $ (57,066) $ 20,175 $ (107,721)
Income (loss) per common share-        
Basic $ 0.86 $ (1.65) $ 0.58 $ (3.14)
Diluted $ 0.85 $ (1.65) $ 0.58 $ (3.14)
Weighted average number of shares-        
Basic 34,849,805 34,664,246 34,755,276 34,273,265
Diluted 35,302,706 34,664,246 35,077,315 34,273,265