Consolidated Income Statements (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
Net sales	$ 600,468	$ 571,164	$ 498,713
Cost of goods sold	435,689	411,342	355,213
Gross profit	164,779	159,822	143,500
Selling, general and administrative expenses	114,141	114,413	101,904
Pension expense	3,739	5,206	3,195
Asset impairment charges	1,179	0	0
Operating income	45,720	40,203	38,401
Other:
Interest expense	7,544	13,662	16,688
Realized and unrealized gain on derivatives	(1,307)	(1,195)	(2,582)
Other expense	181	240	434
Income from continuing operations before tax and equity investment	39,302	27,496	23,861
Tax provision	17,008	12,161	9,637
Loss (gain) from associated company, net of tax	7,101	(6,006)	0
Income from continuing operations, net of tax	15,193	21,341	14,224
Discontinued operations:
Income from discontinued operations, net of tax	9,935	5,789	12,236
Gain on disposal of assets, net of tax	42	14,899	21
Net income from discontinued operations	9,977	20,688	12,257
Net income	$ 25,170	$ 42,029	$ 26,481
Basic and diluted income per share of common stock (in dollars per share)
Income from continuing operations, net of tax, per share	$ 1.23	$ 1.61	$ 1.09
Discontinued operations, net of tax, per share	$ 0.81	$ 1.56	$ 0.94
Net income per share	$ 2.04	$ 3.17	$ 2.03
Weighted-average number of common shares outstanding	12,334	13,251	13,032