Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Revenue:
Total revenue	$ 105,136	$ 94,864	$ 100,077
Operating costs and expenses:
Type of Cost, Good or Service [Extensible List]	Product Sales [Member]	Product Sales [Member]	Product Sales [Member]
Product costs	$ 17,177	$ 15,317	$ 13,639
Research and development	46,734	50,188	52,885
Selling, general and administrative	30,677	28,392	23,950
Acquired intangible asset amortization	2,793	2,218	2,405
Acquisition transaction, integration and other costs	1,049
Contingent consideration expense (gain)	3		(161)
Acquired in-process research and development			890
Total operating costs and expenses	98,433	96,115	93,608
Operating income (loss)	6,703	(1,251)	6,469
Other (expense) income:
Investment income, net	123	656	1,097
Interest expense	(310)	(133)	(152)
Foreign exchange (loss) gain	(170)	(248)	134
(Loss) gain on strategic investments and other		(478)	10
Other (expense) income	(357)	(203)	1,089
Income (loss) before income taxes	6,346	(1,454)	7,558
Income tax (provision) benefit	(2,109)	2,577	34
Net income	$ 4,237	$ 1,123	$ 7,592
Basic net income per share	$ 0.31	$ 0.08	$ 0.57
Diluted net income per share	$ 0.30	$ 0.08	$ 0.55
Weighted average number of shares outstanding:
Basic	13,765	13,552	13,389
Diluted	13,989	13,812	13,779
Product Sales [Member]
Revenue:
Total revenue	$ 46,478	$ 44,317	$ 40,219
Royalties and License Fees [Member]
Revenue:
Total revenue	47,056	40,634	48,458
Research, Development and Other [Member]
Revenue:
Total revenue	$ 11,602	$ 9,913	$ 11,400