Consolidated Statement of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Net sales	$ 769,970	$ 723,530	$ 705,030
Cost of sales	(587,890)	(529,630)	(504,920)
Gross profit	182,080	193,900	200,110
Selling, general and administrative expenses	(134,480)	(102,530)	(91,210)
Net loss on dispositions of assets	(1,290)	(150)	(90)
Impairment of goodwill and indefinite-lived intangible assets	(134,600)	0	0
Operating profit (loss)	(88,290)	91,220	108,810
Other expense, net:
Interest expense	(14,660)	(13,950)	(13,910)
Other income (expense), net	240	990	(2,540)
Other expense, net	(14,420)	(12,960)	(16,450)
Income (loss) before income taxes	(102,710)	78,260	92,360
Income tax benefit (expense)	22,950	(16,320)	(18,650)
Income (loss) from continuing operations	(79,760)	61,940	73,710
Income from discontinued operations, net of income taxes	0	36,680	9,590
Net income (loss)	$ (79,760)	$ 98,620	$ 83,300
Basic earnings (loss) per share:
Continuing operations	$ (1.83)	$ 1.37	$ 1.61
Discontinued operations	0	0.81	0.21
Net income (loss) per share	$ (1.83)	$ 2.18	$ 1.82
Weighted average common shares—basic	43,581,232	45,303,659	45,824,555
Diluted earnings (loss) per share:
Continuing operations	$ (1.83)	$ 1.36	$ 1.60
Discontinued operations	0	0.80	0.20
Net income (loss) per share	$ (1.83)	$ 2.16	$ 1.80
Weighted average common shares—diluted	43,581,232	45,595,154	46,170,464