CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Net sales	$ 482,566	$ 351,584	$ 1,323,991	$ 1,077,811
Cost of sales	431,521	308,390	1,170,172	963,553
Gross profit	51,045	43,194	153,819	114,258
General and administrative expenses	20,966	22,749	66,740	68,574
Selling expenses	5,590	6,510	18,320	19,394
Amortization of intangible assets	5,631	5,496	17,228	16,484
Impairment and other, net	595	31	(631)	105,455
Income (loss) from operations	18,263	8,408	52,162	(95,649)
Other income (expense):
Interest expense	(5,847)	(5,749)	(18,031)	(17,903)
Other, net	232	(57)	(195)	348
Other expense, net	(5,615)	(5,806)	(18,226)	(17,555)
Income (loss) before income tax expense (benefit)	12,648	2,602	33,936	(113,204)
Income tax expense (benefit)	1,640	(1,285)	7,459	(10,298)
Net income (loss)	$ 11,008	$ 3,887	$ 26,477	$ (102,906)
Net income (loss) per share:
Basic (in usd per share)	$ 0.22	$ 0.07	$ 0.52	$ (1.94)
Diluted (in usd per share)	$ 0.22	$ 0.07	$ 0.51	$ (1.94)
Weighted average common shares outstanding (in thousands):
Basic (in shares)	49,974	52,912	51,116	52,980
Diluted (in shares)	50,581	53,380	51,785	52,980
Dividends declared per share (in usd per share)	$ 0.08	$ 0.08	$ 0.24	$ 0.24