Consolidated Income Statements (unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Consolidated Income Statements (unaudited) [Abstract]
Gross sales	$ 74,581	$ 70,559
Commissions, allowances and rebates	163	535
Net sales	74,418	70,024
Other	467	204
Net revenues	74,885	70,228
Cost of goods sold	50,136	47,800
Gross profit	24,749	22,428
Operating expenses:
Selling, general and administrative expenses	11,104	9,960
Research and development expenses	2,194	2,358
Total operating expenses	13,298	12,318
Gain on sale of asset	4,680	0
Operating profit	16,131	10,110
Other expenses/(income):
Interest expense, net	495	651
Other (income)/expenses, net	(32)	8
Equity in losses of partially-owned affiliates	481	208
Income before income taxes	15,187	9,243
Provision for income taxes	3,762	2,205
Income from continuing operations	11,425	7,038
Loss from discontinued operations, net of tax	(257)	0
Net income	$ 11,168	$ 7,038
Basic earnings/(loss) per share of common stock:
Income from continuing operations (in dollars per share)	$ 0.38	$ 0.24
Loss from discontinued operations, net of tax (in dollars per share)	$ (0.01)	$ 0
Net income (in dollars per share)	$ 0.37	$ 0.24
Diluted earnings/(loss) per share of common stock:
Income from continuing operations (in dollars per share)	$ 0.37	$ 0.24
Loss from discontinued operations, net of tax (in dollars per share)	$ (0.01)	$ 0
Net income (in dollars per share)	$ 0.36	$ 0.24
Weighted average shares outstanding:
Basic (in shares)	29,970	29,602
Effect of dilutive stock based compensation (in shares)	818	284
Diluted (in shares)	30,788	29,886