Consolidated Statement of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Net sales	$ 817,740	$ 794,020	$ 863,980
Cost of sales	(598,600)	(583,540)	(627,870)
Gross profit	219,140	210,480	236,110
Selling, general and administrative expenses	(129,570)	(153,710)	(162,350)
Net loss on dispositions of assets	(1,080)	(1,870)	(2,330)
Impairment of goodwill and indefinite-lived intangible assets	0	(98,900)	(75,680)
Operating profit (loss)	88,490	(44,000)	(4,250)
Other expense, net:
Interest expense	(14,400)	(13,720)	(14,060)
Debt financing and related expenses	(6,640)	0	(1,970)
Other expense, net	(1,240)	(510)	(1,840)
Other expense, net	(22,280)	(14,230)	(17,870)
Income (loss) from continuing operations before income taxes	66,210	(58,230)	(22,120)
Income tax benefit (expense)	(35,250)	18,430	(6,540)
Income (loss) from continuing operations	30,960	(39,800)	(28,660)
Loss from discontinued operations, net of income taxes	0	0	(4,740)
Net income (loss)	$ 30,960	$ (39,800)	$ (33,400)
Basic earnings (loss) per share:
Continuing operations	$ 0.68	$ (0.88)	$ (0.64)
Discontinued operations	0.00	0.00	(0.10)
Net income (loss) per share	$ 0.68	$ (0.88)	$ (0.74)
Weighted average common shares—basic	45,682,627	45,407,316	45,123,626
Diluted earnings (loss) per share:
Continuing operations	$ 0.67	$ (0.88)	$ (0.64)
Discontinued operations	0.00	0.00	(0.10)
Net income (loss) per share	$ 0.67	$ (0.88)	$ (0.74)
Weighted average common shares—diluted	45,990,252	45,407,316	45,123,626