Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
NET REVENUES	$ 50,665	$ 48,204	$ 149,084	$ 147,762
COST OF SALES	17,756	17,873	51,020	55,673
GROSS PROFIT	32,909	30,331	98,064	92,089
OPERATING EXPENSES
Research and development	3,546	3,214	10,056	9,685
Selling and marketing	8,085	6,184	21,738	18,745
General and administrative	7,537	6,535	22,306	20,860
Acquisition-related costs			1,481
Total operating expenses	19,168	15,933	55,581	49,290
OPERATING INCOME	13,741	14,398	42,483	42,799
OTHER INCOME (EXPENSE)
Interest income	22	6	42	18
Interest expense	(427)		(470)
Other, net	65	(99)	(163)	(892)
Total other income (expense)	(340)	(93)	(591)	(874)
EARNINGS BEFORE INCOME TAXES	13,401	14,305	41,892	41,925
INCOME TAX PROVISION	4,647	5,203	15,154	14,852
NET EARNINGS	$ 8,754	$ 9,102	$ 26,738	$ 27,073
BASIC EARNINGS PER COMMON SHARE	$ 0.21	$ 0.22	$ 0.64	$ 0.65
DILUTED EARNINGS PER COMMON SHARE	$ 0.21	$ 0.22	$ 0.63	$ 0.64
WEIGHTED AVERAGE NUMBER OF COMMON SHARES OUTSTANDING - BASIC	42,076	41,714	42,000	41,647
EFFECT OF DILUTIVE STOCK OPTIONS AND RESTRICTED SHARES AND UNITS	387	379	379	352
WEIGHTED AVERAGE NUMBER OF COMMON SHARES OUTSTANDING - DILUTED	42,463	42,093	42,379	41,999
ANTI-DILUTIVE SECURITIES:
Common share options and restricted shares and units	465	493	449	567
DIVIDENDS DECLARED PER COMMON SHARE	$ 0.20	$ 0.20	$ 0.60	$ 0.60