Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net sales	$ 319,660	$ 262,915	$ 276,634
Cost of sales	197,414	173,095	173,810
Gross margin	122,246	89,820	102,824
Selling, engineering and administration	77,777	62,286	58,001
Operating earnings	44,469	27,534	44,823
Interest expense, net	998	185	385
Earnings before income taxes	43,471	27,349	44,438
Provision for income taxes	15,439	8,188	15,776
Net earnings	$ 28,032	$ 19,161	$ 28,662
Basic:
from continuing operations (in dollars per share)	$ 1.96	$ 1.28	$ 1.92
Diluted:
from continuing operations (in dollars per share)	$ 1.95	$ 1.27	$ 1.91
Shares used in computation of earnings per share:
Basic (in shares)	14,332	14,971	14,906
Impact of dilutive securities (in shares)	67	78	100
Diluted (in shares)	14,399	15,049	15,006