Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Statement [Abstract]
Net sales	$ 48,824	$ 47,632	$ 144,012	$ 143,310
Cost of sales	24,104	22,328	69,852	67,793
Gross profit	24,720	25,304	74,160	75,517
Operating expenses:
Sales and marketing	10,372	9,920	31,060	30,359
Research and development	7,606	7,779	22,798	23,764
General and administrative	4,850	4,560	16,356	13,808
Restructuring	0	963	(37)	1,259
Total operating expenses	22,828	23,222	70,177	69,190
Operating income	1,892	2,082	3,983	6,327
Other (expense) income, net:
Interest income	58	71	160	217
Interest expense	0	0	(37)	(15)
Other income, net	(59)	(192)	503	(37)
Total other (expense) income, net	(1)	(121)	626	165
Income before income taxes	1,891	1,961	4,609	6,492
Income tax provision (benefit)	363	(346)	851	1,339
Net income	$ 1,528	$ 2,307	$ 3,758	$ 5,153
Net income per common share:
Basic	$ 0.06	$ 0.09	$ 0.14	$ 0.20
Diluted	$ 0.06	$ 0.09	$ 0.14	$ 0.20
Weighted average common shares:
Basic	25,849	25,770	26,057	25,705
Diluted	26,114	26,043	26,323	26,138