Consolidated Condensed Statements of Operations (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Consolidated Condensed Statements of Operations [Abstract]
Net sales	$ 76,233	$ 57,359
Cost of sales	47,369	36,922
Gross margin	28,864	20,437
Selling, engineering and administration	18,676	15,199
Operating earnings	10,188	5,238
Interest expense	205	112
Earnings before income taxes	9,983	5,126
Provision for income taxes	3,734	1,866
Net earnings	$ 6,249	$ 3,260
Earnings per share:
Basic	$ 0.42	$ 0.22
Diluted	$ 0.42	$ 0.22
Dividends declared - Common stock	$ 0.16	$ 0.14
Shares used in computation of earnings per share:
Basic	14,831,780	14,938,758
Impact of dilutive securities	65,837	119,474
Diluted	14,897,617	15,058,232