CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement [Abstract]
Net sales	$ 339,153	$ 626,053	$ 726,227	$ 1,159,227
Cost of sales	304,832	538,403	655,163	1,002,887
Gross profit	34,321	87,650	71,064	156,340
General and administrative expenses	19,633	26,509	45,825	56,649
Selling expenses	4,886	8,494	12,884	16,717
Amortization of intangible assets	5,493	5,109	10,988	10,238
Asset Impairment Charges and Other	(1,690)	0	105,424	0
Income (loss) from operations	5,999	47,538	(104,057)	72,736
Other income (expense):
Interest expense	(5,882)	(7,020)	(12,154)	(14,110)
Other, net	285	1,081	405	912
Other expense, net	(5,597)	(5,939)	(11,749)	(13,198)
Income (loss) before income tax expense (benefit)	402	41,599	(115,806)	59,538
Income tax expense (benefit)	548	10,639	(9,013)	13,798
Net (loss) income	$ (146)	$ 30,960	$ (106,793)	$ 45,740
Net (loss) income per share:
Basic (in usd per share)	$ 0.00	$ 0.56	$ (2.01)	$ 0.83
Diluted (in usd per share)	$ 0.00	$ 0.56	$ (2.01)	$ 0.82
Weighted average common shares outstanding (in thousands):
Basic (in shares)	52,874	55,197	53,015	55,233
Diluted (in shares)	52,874	55,668	53,015	55,719
Dividends declared per share (in usd per share)	$ 0.08	$ 0.08	$ 0.16	$ 0.16