Condensed Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
REVENUES:
Net sales	$ 82,709	$ 81,266	$ 235,419	$ 233,788
Other	106	139	356	409
TOTAL REVENUE	82,815	81,405	235,775	234,197
COST OF GOODS SOLD	41,860	40,710	119,988	119,455
Gross profit	40,955	40,695	115,787	114,742
OPERATING EXPENSES:
Selling, general and administrative	22,399	20,177	68,447	63,873
Research and development	3,140	2,988	8,949	8,410
Total operating expenses	25,539	23,165	77,396	72,283
Income from operations	15,416	17,530	38,391	42,459
OTHER INCOME(EXPENSE)	190	158	570	438
Income before income taxes	15,606	17,688	38,961	42,897
PROVISION FOR INCOME TAXES	(4,572)	(5,500)	(11,875)	(13,959)
NET INCOME	$ 11,034	$ 12,188	$ 27,086	$ 28,938
NET INCOME PER SHARE
Basic (in dollars per share)	$ 0.75	$ 0.85	$ 1.85	$ 2.04
Diluted (in dollars per share)	$ 0.72	$ 0.82	$ 1.79	$ 1.98
WEIGHTED AVERAGE NUMBER OF SHARES
Basic (in shares)	14,684	14,321	14,603	14,153
Diluted (in shares)	15,324	14,826	15,139	14,613