Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net sales	$ 642,411	$ 584,956	$ 1,174,535	$ 1,116,934
Cost of sales	504,951	507,774	946,737	1,039,640
Gross profit	137,460	77,182	227,798	77,294
Operating expenses:
Selling, general and administrative	51,770	50,934	110,357	96,286
Research and development	22,483	24,395	48,096	46,272
Production start-up	6,311	10,437	10,793	19,959
Litigation loss	6,000	0	6,000	0
Total operating expenses	86,564	85,766	175,246	162,517
Operating income (loss)	50,896	(8,584)	52,552	(85,223)
Foreign currency (loss) income, net	(1,299)	1,726	(1,697)	1,898
Interest income	3,674	13,510	13,004	27,769
Interest expense, net	(3,254)	(8,921)	(10,043)	(19,042)
Other expense, net	(3,195)	(4,438)	(5,417)	(929)
Income (loss) before taxes and equity in earnings	46,822	(6,707)	48,399	(75,527)
Income tax (expense) benefit	(10,214)	(11,744)	79,001	(10,350)
Equity in earnings, net of tax	303	(97)	215	(270)
Net income (loss)	$ 36,911	$ (18,548)	$ 127,615	$ (86,147)
Net income (loss) per share:
Basic	$ 0.35	$ (0.18)	$ 1.21	$ (0.82)
Diluted	$ 0.35	$ (0.18)	$ 1.20	$ (0.82)
Weighted-average number of shares used in per share calculations:
Basic	105,927	105,369	105,761	105,208
Diluted	106,473	105,369	106,429	105,208