Condensed Consolidated Statements Of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Condensed Consolidated Statements Of Income (Loss) [Abstract]
Sales	$ 525,951	$ 555,229	$ 1,531,881	$ 1,759,651
Cost of sales	479,597	506,274	1,407,494	1,611,436
Gross profit	46,354	48,955	124,387	148,215
Selling, general and administrative expenses	29,724	30,947	89,815	92,461
Amortization of intangible assets	2,368	2,367	7,120	7,095
Restructuring charges and other costs	7,161	5,843	15,480	10,833
Ransomware incident related costs (recovery), net	(1,558)	0	(1,305)	0
Income from operations	8,659	9,798	13,277	37,826
Interest expense	(2,136)	(1,687)	(6,189)	(5,014)
Interest income	154	734	1,040	3,084
Other income (expense), net	439	(136)	(191)	2,276
Income before income taxes	7,116	8,709	7,937	38,172
Income tax expense	1,201	1,573	1,577	7,816
Net income	$ 5,915	$ 7,136	$ 6,360	$ 30,356
Earnings per share:
Basic	$ 0.16	$ 0.19	$ 0.17	$ 0.78
Diluted	$ 0.16	$ 0.19	$ 0.17	$ 0.77
Weighted-average number of shares outstanding:
Basic	36,467	37,419	36,565	38,813
Diluted	36,544	37,645	36,821	39,184