Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Consolidated Statements Of Income (Loss) [Abstract]
Sales	$ 2,268,095	$ 2,566,465	$ 2,454,479
Cost of sales	2,067,689	2,345,872	2,228,559
Gross profit	200,406	220,593	225,920
Selling, general and administrative expenses	141,618	143,205	130,401
Amortization of intangible assets	9,461	9,485	10,065
Restructuring charges and other costs	13,101	9,365	8,628
Ransomware related incident costs, net	7,681	0	0
Income from operations	28,545	58,538	76,826
Interest expense	(6,664)	(10,473)	(9,405)
Interest income	3,829	6,848	5,370
Other income (expense)	1,559	628	(1,786)
Income before income taxes	27,269	55,541	71,005
Income tax expense	3,844	32,724	102,906
Net income (loss)	$ 23,425	$ 22,817	$ (31,901)
Earnings (loss) per share:
Basic	$ 0.61	$ 0.49	$ (0.64)
Diluted	$ 0.60	$ 0.49	$ (0.64)
Weighted-average number of shares outstanding:
Basic	38,338	46,332	49,680
Diluted	38,763	46,655	49,680