CONSOLIDATED CONDENSED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Statement Of Operations [Abstract]
NET SALES	$ 209,986	$ 176,964
COST OF GOODS SOLD	148,405	130,781
Gross profit	61,581	46,183
OPERATING EXPENSES
Selling, general and administrative	32,330	30,376
Research and development	12,920	10,080
Other operating expenses	1,988	1,951
Total operating expenses	47,238	42,407
Income from operations	14,343	3,776
OTHER INCOME (EXPENSES)	(1,350)	521
Income before income taxes and noncontrolling interest	12,993	4,297
INCOME TAX PROVISION	2,547	6,574
NET INCOME (LOSS)	10,446	(2,277)
Less: NET (INCOME) LOSS attributable to noncontrolling interest	(244)	351
NET INCOME (LOSS) attributable to common stockholders	$ 10,202	$ (1,926)
EARNINGS (LOSS) PER SHARE attributable to common stockholders
Basic	$ 0.22	$ (0.04)
Diluted	$ 0.21	$ (0.04)
Number of shares used in computation
Basic	46,699	46,021
Diluted	47,996	46,021