Consolidated Statement of Income Statement - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net sales	$ 217,100	$ 199,830
Cost of sales	(156,720)	(148,010)
Gross profit	60,380	51,820
Selling, general and administrative expenses	(25,170)	(35,910)
Operating profit	35,210	15,910
Other expense, net:
Interest expense	(3,700)	(3,550)
Other expense, net	(560)	(780)
Other expense, net	(4,260)	(4,330)
Income before income tax expense	30,950	11,580
Income tax expense	(6,630)	(4,590)
Net income	$ 24,320	$ 6,990
Basic earnings per share
Net income per share	$ 0.53	$ 0.15
Weighted average common shares—basic	45,779,966	45,570,495
Diluted earnings per share
Net income per share	$ 0.53	$ 0.15
Weighted average common shares—diluted	46,229,337	45,908,958