Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
NET REVENUES	$ 50,140	$ 50,665	$ 151,074	$ 149,084
COST OF SALES	18,943	17,756	56,896	51,020
GROSS PROFIT	31,197	32,909	94,178	98,064
OPERATING EXPENSES
Research and development	3,906	3,546	11,218	10,056
Selling and marketing	7,885	8,085	23,411	21,738
General and administrative	8,474	7,537	24,346	22,306
Goodwill impairment charge	6,628		6,628
Acquisition-related costs				1,481
Total operating expenses	26,893	19,168	65,603	55,581
OPERATING INCOME	4,304	13,741	28,575	42,483
OTHER INCOME (EXPENSE)
Interest income	51	22	102	42
Interest expense	(407)	(427)	(1,238)	(470)
Other, net	(2)	65	356	(163)
Total other expense	(358)	(340)	(780)	(591)
EARNINGS BEFORE INCOME TAXES	3,946	13,401	27,795	41,892
INCOME TAX PROVISION	3,706	4,647	11,964	15,154
NET EARNINGS	$ 240	$ 8,754	$ 15,831	$ 26,738
BASIC EARNINGS PER COMMON SHARE	$ 0.01	$ 0.21	$ 0.38	$ 0.64
DILUTED EARNINGS PER COMMON SHARE	$ 0.01	$ 0.21	$ 0.37	$ 0.63
WEIGHTED AVERAGE NUMBER OF COMMON SHARES OUTSTANDING - BASIC	42,203	42,076	42,184	42,000
EFFECT OF DILUTIVE STOCK OPTIONS AND RESTRICTED SHARE UNITS	390	387	372	379
WEIGHTED AVERAGE NUMBER OF COMMON SHARES OUTSTANDING - DILUTED	42,593	42,463	42,556	42,379
ANTI-DILUTIVE SECURITIES:
Common share options and restricted share units	861	465	872	449
DIVIDENDS DECLARED PER COMMON SHARE	$ 0.125	$ 0.200	$ 0.450	$ 0.600