Condensed Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
REVENUES:
Net sales	$ 74,173	$ 75,383
Other	126	128
TOTAL REVENUE	74,299	75,511
COST OF GOODS SOLD	37,505	40,546
Gross profit	36,794	34,965
OPERATING EXPENSES:
Selling, general and administrative	22,866	20,890
Research and development	1,903	2,693
Total operating expenses	24,769	23,583
Income from operations	12,025	11,382
OTHER INCOME(EXPENSE)	168	135
Income before income taxes	12,193	11,517
PROVISION FOR INCOME TAXES	(3,508)	(3,916)
NET INCOME	$ 8,685	$ 7,601
NET INCOME PER SHARE
Basic (in dollars per share)	$ 0.60	$ 0.54
Diluted (in dollars per share)	$ 0.58	$ 0.53
WEIGHTED AVERAGE NUMBER OF SHARES
Basic (in shares)	14,507	13,956
Diluted (in shares)	15,053	14,318