Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Operating activities:
Net income	$ 1,303	$ 9,366	$ 16,708
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Depreciation of property, equipment and improvements	2,835	2,900	2,742
Amortization of identifiable intangible assets	9,435	2,597	1,872
Stock-based compensation	4,854	4,659	3,654
Excess tax benefits from stock-based compensation	0	(326)	(212)
Deferred income tax (benefit) provision	(508)	(2,108)	1,115
Gain on sale of property, equipment and improvements	(622)	0	0
Gain on sale of business	0	0	(2,870)
Change in fair value of contingent consideration	1,377	(4,364)	(441)
Bad debt/product return provision	1,120	361	168
Inventory obsolescence	2,056	1,850	1,734
Restructuring charges, net	301	2,515	747
Other	67	(9)	66
Changes in operating assets and liabilities (net of acquisitions):
Accounts receivable	(17,002)	833	(1,188)
Inventories	(9,186)	(4,484)	3,993
Other assets	(1,412)	562	597
Income taxes	697	(3)	(1,589)
Accounts payable	2,728	(3,536)	1,612
Accrued expenses	(821)	(8,338)	(1,619)
Net cash (used in) provided by operating activities	(2,778)	2,475	27,089
Investing activities:
Purchase of marketable securities	0	(61,964)	(74,759)
Proceeds from maturities of marketable securities	32,032	87,105	73,706
Proceeds from sale of business	2,000	3,000	2,849
Acquisition of businesses, net of cash acquired	(56,258)	(30,111)	(2,860)
Proceeds from sale of property and equipment	731	0	0
Proceeds from sale of investment	0	0	13
Purchase of property, equipment, improvements and certain other intangible assets	(1,842)	(1,773)	(2,729)
Net cash used in investing activities	(23,337)	(3,743)	(3,780)
Financing activities:
Acquisition earn-out payments	0	(518)	0
Excess tax benefits from stock-based compensation	0	326	212
Proceeds from stock option plan transactions	5,460	3,502	7,191
Proceeds from employee stock purchase plan transactions	1,115	685	896
Repurchase of common stock	(748)	(938)	(550)
Net cash provided by financing activities	5,827	3,057	7,749
Effect of exchange rate changes on cash and cash equivalents	80	706	(349)
Net (decrease) increase in cash and cash equivalents	(20,208)	2,495	30,709
Cash and cash equivalents, beginning of period	78,222	75,727	45,018
Cash and cash equivalents, end of period	58,014	78,222	75,727
Supplemental disclosures of cash flow information:
Interest paid	10	1	9
Income taxes paid, net	1,235	2,129	3,029
Supplemental schedule of non-cash investing and financing activities:
Accrual for capitalized intangible asset	(78)	(36)	(183)
Receivable related to sale of business	0	0	4,956
Liability related to acquisition of business	$ (2,300)	$ (1,310)	$ (10,550)