Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Operating activities:
Net income	$ 16,708	$ 6,588	$ 1,751
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of property, equipment and improvements	2,742	2,949	3,557
Amortization of identifiable intangible assets	1,872	2,910	3,589
Stock-based compensation	3,654	4,301	4,330
Excess tax benefits from stock-based compensation	(212)	0	(44)
Deferred income tax provision (benefit)	1,115	(769)	(2,783)
Gain on insurance settlement related to property and equipment	0	(1,375)	0
Gain on sale of business	(2,870)	0	0
Change in fair value of contingent consideration	(441)	0	0
Bad debt/product return provision	168	357	98
Inventory obsolescence	1,734	1,284	860
Restructuring charges, net	747	509	81
Other	66	87	3
Changes in operating assets and liabilities (net of acquisition):
Accounts receivable	(1,188)	(1,794)	(2,730)
Inventories	3,993	(1,913)	(5,966)
Other assets	597	241	210
Income taxes	(1,589)	387	(1,408)
Accounts payable	1,612	(3,769)	970
Accrued expenses	(1,619)	4,081	(709)
Net cash provided by operating activities	27,089	14,074	1,809
Investing activities:
Purchase of marketable securities	(74,759)	(54,427)	(27,420)
Proceeds from maturities of marketable securities	73,706	38,028	47,420
Proceeds from sale of business	2,849	0	0
Acquisition of businesses, net of cash acquired	(2,860)	0	0
Proceeds from insurance settlement related to property and equipment	0	1,400	0
Proceeds from sale of property and equipment	0	45	0
Proceeds from sale of investment	13	0	0
Purchase of property, equipment, improvements and certain other intangible assets	(2,729)	(4,500)	(3,421)
Net cash (used in) provided by in investing activities	(3,780)	(19,454)	16,579
Financing activities:
Excess tax benefits from stock-based compensation	212	0	44
Proceeds from stock option plan transactions	7,191	6,559	3,689
Proceeds from employee stock purchase plan transactions	896	925	1,009
Purchase of common stock	(550)	(2,339)	(15,702)
Net cash provided by (used in) financing activities	7,749	5,145	(10,960)
Effect of exchange rate changes on cash and cash equivalents	(349)	(2,237)	(1,258)
Net increase (decrease) in cash and cash equivalents	30,709	(2,472)	6,170
Cash and cash equivalents, beginning of period	45,018	47,490	41,320
Cash and cash equivalents, end of period	75,727	45,018	47,490
Supplemental disclosures of cash flow information:
Interest paid	9	4	5
Income taxes paid, net	3,029	1,296	3,197
Supplemental schedule of non-cash investing and financing activities:
Accrual for capitalized intangible asset	(183)	(17)	0
Receivable related to sale of business	4,956	0	0
Liability related to acquisition of business	(10,550)	0	0
Accrual for purchase of common stock	$ 0	$ 0	$ (100)