Consolidated Income Statements - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Net sales	$ 166,475	$ 168,545	$ 304,457	$ 304,032
Cost of goods sold	118,299	120,918	217,903	219,254
Gross profit	48,176	47,627	86,554	84,778
Selling, general and administrative expenses	30,892	28,937	61,751	59,630
Pension expense	2,072	1,105	4,145	2,210
Operating income	15,212	17,585	20,658	22,938
Other:
Interest expense	1,107	1,603	2,275	3,149
Realized and unrealized (gain) loss on derivatives	(312)	606	(105)	466
Other expense	113	77	204	146
Income from continuing operations before tax and equity investment	14,304	15,299	18,284	19,177
Tax provision	5,867	6,648	7,511	8,455
Loss from associated company, net of tax	2,161	1,242	1,239	6,540
Income from continuing operations, net of tax	6,276	7,409	9,534	4,182
Discontinued operations:
Income from discontinued operations, net of tax	0	3,667	565	6,482
(Loss) gain on disposal of assets, net of tax	(147)	0	89,373	42
Net (loss) income from discontinued operations	(147)	3,667	89,938	6,524
Net income	$ 6,129	$ 11,076	$ 99,472	$ 10,706
Basic and diluted income (loss) per share of common stock
Income from continuing operations, net of tax, per share (in dollars per share)	$ 0.58	$ 0.56	$ 0.88	$ 0.32
Discontinued operations, net of tax, per share (in dollars shares)	(0.01)	0.28	8.35	0.50
Net income per common share (in dollars per share)	$ 0.57	$ 0.84	$ 9.23	$ 0.82
Weighted-average number of common shares outstanding (in shares)	10,784	13,114	10,782	13,055