CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Net sales	$ 59,492	$ 55,404	$ 115,451	$ 108,448
Cost of sales	29,163	28,149	57,014	55,338
Gross profit	30,329	27,255	58,437	53,110
Operating expenses
Selling, general and administrative	21,779	19,789	42,121	39,343
Amortization of intangible assets	999	728	1,980	1,460
Income from operations	7,551	6,738	14,336	12,307
Interest and other expense, net	322	273	596	570
Income before provision for income taxes	7,229	6,465	13,740	11,737
Provision for income taxes	2,611	2,369	4,881	4,290
Net income	4,618	4,096	8,859	7,447
Other comprehensive income (loss):
Foreign currency translation adjustment, net of tax	62	(109)	(17)	(330)
Comprehensive income	$ 4,680	$ 3,987	$ 8,842	$ 7,117
Net income per common share
Basic (in dollars per share)	$ 0.49	$ 0.43	$ 0.94	$ 0.77
Diluted (in dollars per share)	$ 0.49	$ 0.43	$ 0.94	$ 0.77
Weighted average common shares outstanding
Basic (in shares)	9,401,972	9,622,051	9,430,878	9,637,753
Dilutive effect of stock options (in shares)	0	4,874	0	5,884
Diluted (in shares)	9,401,972	9,626,925	9,430,878	9,643,637