Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Operating Activities:
Net (loss) income	$ (4,457)	$ 3,926	$ 9,985
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation and amortization	6,431	5,555	4,873
Stock-based compensation	4,807	3,472	3,844
Contingent consideration expense (gain)	675	(127)	1,492
Unrealized foreign exchange (gain) loss	(148)	474	444
Acquired in-process research and development	7,888
Deferred taxes	(2,277)	1,000	261
Gains on strategic investments	(177)	(43)	(514)
Provision for bad debts	85	208
Impairment losses on intangible assets		427
Property and equipment disposal (gain) loss		6	(66)
Other, net	45		13
Change in operating assets and liabilities
Accounts receivable	(1,773)	(528)	911
Inventories	(513)	97	(143)
Prepaids and other	(1,584)	(599)	409
Accounts payable and accrued liabilities	5,241	368	3,710
Income taxes	(842)	(59)	76
Deferred revenue	20,651	(124)	(129)
Net cash provided by operating activities	34,052	14,053	25,166
Investing Activities:
Purchases of property and equipment	(9,092)	(6,432)	(8,192)
Cash proceeds from sale of property and equipment			89
Purchases of available-for-sale securities	(81,536)	(73,671)	(24,517)
Sales and maturities of available-for-sale securities	71,951	63,871	2,498
Purchase of in-process research and development (Note 11)	(5,000)
Payments for acquisition, net of cash acquired			(25,859)
Cash received from strategic investments	177	43	513
Net cash used in investing activities	(23,500)	(16,189)	(55,468)
Financing Activities:
Issuance of common stock	2,089	444	494
Repurchase of common stock		(4,702)
Payments for taxes related to net share settlement of equity awards	(4,557)	(2,156)	(388)
Payment of deferred financing costs		(96)
Payment of contingent consideration	(925)		(305)
Net cash used in financing activities	(3,393)	(6,510)	(199)
Effect of exchange rate changes on cash	(25)	193	(100)
Net change in cash and cash equivalents	7,134	(8,453)	(30,601)
Cash, Restricted Cash and Cash Equivalents:
Beginning of year	16,534	24,987	55,588
End of year	23,668	16,534	24,987
Supplemental Information:
Cash paid for income taxes	914	2,114	6,710
Noncash financing and investing activities:
Acquisition of property and equipment on account, net of refundable credits in other current assets	632	$ 109	50
Acquisition of property and equipment in long-term deferred rent	1,200
Acquisition of in process research and development in other long-term liabilities	2,888
Accrual of employee taxes on common stock exercises	$ 130		1,585
Contingent consideration and debt assumed in acquisitions			$ 12,584