CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Net sales	$ 351,584	$ 580,908	$ 1,077,811	$ 1,740,135
Cost of sales	308,390	503,173	963,553	1,506,060
Gross profit	43,194	77,735	114,258	234,075
General and administrative expenses	22,749	25,353	68,574	82,002
Selling expenses	6,510	8,998	19,394	25,715
Amortization of intangible assets	5,496	5,115	16,484	15,353
Asset Impairment Charges and Other	31	0	105,455	0
Income (loss) from operations	8,408	38,269	(95,649)	111,005
Other income (expense):
Interest expense	(5,749)	(6,713)	(17,903)	(20,823)
Other, net	(57)	1,333	348	2,245
Other expense, net	(5,806)	(5,380)	(17,555)	(18,578)
Income (loss) before income tax (benefit) expense	2,602	32,889	(113,204)	92,427
Income tax (benefit) expense	(1,285)	7,429	(10,298)	21,227
Net income (loss)	$ 3,887	$ 25,460	$ (102,906)	$ 71,200
Net income (loss) per share:
Basic (in usd per share)	$ 0.07	$ 0.47	$ (1.94)	$ 1.30
Diluted (in usd per share)	$ 0.07	$ 0.46	$ (1.94)	$ 1.28
Weighted average common shares outstanding (in thousands):
Basic (in shares)	52,912	54,413	52,980	54,975
Diluted (in shares)	53,380	55,019	52,980	55,502
Dividends declared per share (in usd per share)	$ 0.08	$ 0.08	$ 0.24	$ 0.24