CONSOLIDATED STATEMENTS OF EARNINGS (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Statement [Abstract]
Sales	$ 932,135	$ 645,643	$ 521,359
Cost of sales	705,078	487,125	408,815
Gross profit	227,057	158,518	112,544
Selling, general and administrative expenses	110,733	89,859	75,120
Acquisition expenses	7,066
Litigation reserve	1,780	1,000	6,000
Operating income	107,478	67,659	31,424
Interest income	116	54	899
Interest expense	(1,643)	(562)	(650)
Other income (expense), net	(482)	294	1,339
Earnings from continuing operations before income tax provision	105,469	67,445	33,012
Income tax provision	39,498	23,914	10,533
Earnings from continuing operations	65,971	43,531	22,479
Earnings (loss) from discontinued operations, net of tax	0	292	(453)
Net earnings	$ 65,971	$ 43,823	$ 22,026
Basic earnings per share
Earnings from continuing operations (in dollars per share)	$ 2.17	$ 1.45	$ 0.76
Earnings (loss) from discontinued operations (in dollars per share)	$ 0	$ 0.01	$ (0.02)
Net earnings (in dollars per share)	$ 2.17	$ 1.46	$ 0.74
Diluted earnings per share
Earnings from continuing operations (in dollars per share)	$ 2.14	$ 1.44	$ 0.76
Earnings (loss) from discontinued operations (in dollars per share)	$ 0	$ 0.01	$ (0.02)
Net earnings (in dollars per share)	$ 2.14	$ 1.45	$ 0.74