Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Consolidated Statements of Operations [Abstract]
Net sales	$ 262,915	$ 276,634	$ 250,337
Cost of sales	173,095	173,810	153,323
Gross margin	89,820	102,824	97,014
Selling, engineering and administration	62,286	58,001	54,771
Operating earnings	27,534	44,823	42,243
Interest expense (income), net	185	385	(90)
Earnings from continuing operations before income taxes	27,349	44,438	42,333
Provision for income taxes (Note 8)	8,188	15,776	15,553
Earnings from continuing operations	19,161	28,662	26,780
Earnings from discontinued operations net of income taxes (Note 8)			7,390
Net earnings	$ 19,161	$ 28,662	$ 34,170
Basic:
from continuing operations	$ 1.28	$ 1.92	$ 1.81
from discontinued operations			$ 0.50
Total basic	$ 1.28	$ 1.92	$ 2.31
Diluted:
from continuing operations	$ 1.27	$ 1.91	$ 1.79
from discontinued operations			$ 0.49
Total diluted	$ 1.27	$ 1.91	$ 2.28
Shares used in computation of earnings per share:
Basic	14,971	14,906	14,800
Impact of dilutive securities	78	100	148
Diluted	15,049	15,006	14,948