Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Net sales	$ 1,476,353	$ 1,578,203	$ 1,328,297
Cost of sales	1,086,644	1,148,232	950,701
Gross profit	389,708	429,971	377,596
Selling, general and administrative expenses	206,886	231,918	207,493
Research and development costs	19,874	20,320	18,159
Other expenses, net	12,169	6,061	7,581
Restructuring income	0	40,253	0
Restructuring expenses	3,628	15,620	6,492
Income from operations	147,151	196,305	137,871
Interest and other financial expense, net	27,572	28,642	44,135
Reclassification of actuarial losses from AOCI	0	0	9,687
Income from operations before income taxes and equity in earnings of affiliated companies	119,579	167,663	84,049
Income tax expense	33,216	46,944	19,736
Equity in earnings of affiliated companies, net of tax	558	591	547
Net income	$ 86,920	$ 121,310	$ 64,860
Weighted-average shares outstanding (in thousands of shares):
Basic (in shares)	59,986	59,567	59,320
Diluted (in shares)	61,300	61,049	60,674
Earnings per share (USD per share):
Basic (in USD per share)	$ 1.45	$ 2.04	$ 1.09
Diluted (in USD per share)	1.42	1.99	1.07
Dividends per share (in USD per share)	$ 0.80	$ 0.80	$ 0.77