Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Operating Activities:
Net income (loss)		$ 7,592	$ (4,457)	$ 3,926
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization		7,312	6,431	5,555
Stock-based compensation		5,077	4,807	3,472
Payment of contingent consideration obligations in excess of acquisition-date value		(2,041)
Contingent consideration (gain) expense		(161)	675	(127)
Acquired in-process research and development		890	7,888
Deferred taxes	[1]	(1,088)	(2,277)	1,000
Gains on strategic investments		(7)	(177)	(43)
Provision for bad debts		160	85	208
Impairment losses on intangible assets		259		427
Property and equipment disposal loss		(10)		6
Unrealized foreign exchange (gain) loss			(148)	474
Other, net		1	45
Change in operating assets and liabilities
Accounts receivable and contract asset	[1]	(1,630)	(1,773)	(528)
Inventories		(543)	(513)	97
Prepaids and other		(2,131)	(1,584)	(599)
Accounts payable		(765)	155	1,101
Accrued liabilities		(2,187)	5,086	(733)
Deferred revenue	[1]	(3,512)	20,651	(124)
Income taxes	[1]	822	(842)	(59)
Net cash provided by operating activities		8,038	34,052	14,053
Investing Activities:
Purchases of property and equipment		(5,998)	(9,092)	(6,432)
Cash proceeds from sale of property and equipment		10
Purchases of available-for-sale securities		(44,973)	(81,536)	(73,671)
Sales and maturities of available-for-sale securities		61,458	71,951	63,871
Acquisition of in-process research and development (Note 10)		(750)	(5,000)
Cash received from strategic investments		7	177	43
Net cash used in investing activities		9,754	(23,500)	(16,189)
Financing Activities:
Issuance of common stock		723	2,089	444
Payments for taxes related to net share settlement of equity awards		(2,688)	(4,557)	(2,156)
Payment of contingent consideration		(9,064)	(925)
Payment of deferred financing costs				(96)
Repurchase of common stock				(4,702)
Net cash used in financing activities		(11,029)	(3,393)	(6,510)
Effect of exchange rate changes on cash		(70)	(25)	193
Net change in cash and cash equivalents		6,693	7,134	(8,453)
Cash and Cash Equivalents:
Beginning of year		23,668	16,534	24,987
End of year		30,361	23,668	16,534
Supplemental Information:
Cash paid for income taxes		193	914	2,114
Noncash financing and investing activities:
Acquisition of property and equipment on account, net of refundable credits in other current assets		202	632	$ 109
Acquisition of property and equipment in long-term deferred rent			1,200
Acquisition of in process research and development in other long-term liabilities		140	2,888
Accrual of employee taxes on common stock exercises		$ 104	$ 130

[1] Amounts presented are net of impact from adoption of ASC Topic 606.