Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands		6 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Operating activities:
Net income (loss)		$ 6,024	$ (4,613)	[1]
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation of property, equipment and improvements		2,217	1,546	[1]
Amortization of intangible assets		4,609	4,287	[1]
Stock-based compensation		2,707	2,378	[1]
Deferred income tax provision		1,338	2,808	[1]
Gain on sale of property and equipment		(4,395)	5	[1]
Change in fair value of contingent consideration		810	(425)	[1]
Provision for bad debt and product returns		568	395	[1]
Provision for inventory obsolescence		900	900	[1]
Restructuring reversal		(67)	0	[1]
Other		(116)	25	[1]
Changes in operating assets and liabilities (net of acquisitions)		(8,393)	(12,287)	[1]
Net cash provided by (used in) operating activities		6,202	(4,981)	[1]
Investing activities:
Proceeds from maturities and sales of marketable securities		2,252	29,513	[1]
Proceeds from sale of business		0	2,000	[1]
Acquisition of businesses, net of cash acquired		0	(56,588)	[1]
Proceeds from sale of property and equipment		10,047	0	[1]
Purchase of property, equipment, improvements and certain other intangible assets		(7,346)	(785)	[1]
Net cash provided by (used in) investing activities		4,953	(25,860)	[1]
Financing activities:
Acquisition earn-out payments		(2,348)	0	[1]
Proceeds from stock option plan transactions		3,751	3,427	[1]
Proceeds from employee stock purchase plan transactions		549	618	[1]
Purchases of common stock		(1,044)	(681)	[1]
Net cash provided by financing activities		908	3,364	[1]
Effect of exchange rate changes on cash and cash equivalents		(484)	1,646	[1]
Net increase (decrease) in cash and cash equivalents		11,579	(25,831)	[1]
Cash and cash equivalents, beginning of period	[1]	58,014	78,222
Cash and cash equivalents, end of period		69,593	52,391	[1]
Supplemental schedule of non-cash investing and financing activities
Transfer of inventory to property, equipment and improvements		(654)	(827)	[1]
Liability related to acquisition of business		0	(2,300)	[1]
Accrual for purchase of property, equipment, improvements and certain other intangible assets		$ (20)	$ (27)	[1]

[1] Prior period information has been restated for the adoption of ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” which we adopted on October 1, 2018.