Condensed Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
REVENUES:
Net sales	$ 78,537	$ 77,139	$ 152,710	$ 152,522
Other	124	142	250	270
TOTAL REVENUE	78,661	77,281	152,960	152,792
COST OF GOODS SOLD	40,623	38,199	78,128	78,745
Gross profit	38,038	39,082	74,832	74,047
OPERATING EXPENSES:
Selling, general and administrative	23,182	22,806	46,048	43,696
Research and development	3,906	2,729	5,809	5,422
Total operating expenses	27,088	25,535	51,857	49,118
Income from operations	10,950	13,547	22,975	24,929
OTHER INCOME(EXPENSE)	212	145	380	280
Income before income taxes	11,162	13,692	23,355	25,209
PROVISION FOR INCOME TAXES	(3,795)	(4,543)	(7,303)	(8,459)
NET INCOME	$ 7,367	$ 9,149	$ 16,052	$ 16,750
NET INCOME PER SHARE
Basic (in dollars per share)	$ 0.50	$ 0.65	$ 1.10	$ 1.19
Diluted (in dollars per share)	$ 0.48	$ 0.63	$ 1.06	$ 1.16
WEIGHTED AVERAGE NUMBER OF SHARES
Basic (in shares)	14,617	14,179	14,562	14,067
Diluted (in shares)	15,216	14,620	15,147	14,484