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
CONSOLIDATED INCOME STATEMENTS [Abstract]
Gross Sales	$ 374,150	$ 317,212	$ 277,931
Commissions, allowances and rebates	2,306	1,351	2,503
Net sales	371,844	315,861	275,428
Other revenues	2,769	2,315	1,073
Net revenues	374,613	318,176	276,501
Cost of goods sold	250,815	215,272	186,014
Gross profit	123,798	102,904	90,487
Selling, general and administrative expenses	52,489	47,568	45,248
Research and development expenses	13,075	10,387	9,544
Total operating expenses	65,564	57,955	54,792
Loss on voluntary pension settlement	7,170	0	0
Gain on sale of asset	(1,234)	(4,680)	0
Operating profit	52,298	49,629	35,695
Other expenses/(income)
Interest expense, net	2,174	2,242	2,439
Equity in losses of partially-owned affiliates	4,623	2,262	1,766
Other (income)/expenses, net	(5)	118	122
Income before income taxes	45,506	45,007	31,368
(Benefit)/provision for income taxes	(12,627)	14,732	(31,861)
Income from continuing operations	58,133	30,275	63,229
Loss from discontinued operations, net of tax	(830)	(4,360)	(926)
Net income	$ 57,303	$ 25,915	$ 62,303
Basic earnings per share
Income from continuing operations (in dollars per share)	$ 1.89	$ 1.00	$ 2.13
Loss from discontinued operations, net of tax (in dollars per share)	$ (0.03)	$ (0.14)	$ (0.03)
Net income (in dollars per share)	$ 1.86	$ 0.86	$ 2.10
Diluted earnings per share
Income from continuing operations (in dollars per share)	$ 1.84	$ 0.98	$ 2.09
Loss from discontinued operations, net of tax (in dollars per share)	$ (0.03)	$ (0.14)	$ (0.03)
Net income (in dollars per share)	$ 1.81	$ 0.84	$ 2.06
Weighted average shares outstanding:
Basic weighted average shares outstanding (in shares)	30,763	30,150	29,703
Effect of dilutive stock based compensation (in shares)	880	751	611
Diluted weighted average shares outstanding (in shares)	31,643	30,901	30,314