Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Revenue:
Total revenue	$ 94,864	$ 100,077	$ 81,336
Operating costs and expenses:
Type of Cost, Good or Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Product costs	$ 15,317	$ 13,639	$ 13,997
Research and development	50,188	52,885	40,973
Selling, general and administrative	28,392	23,950	24,111
Acquired in-process research and development		890	7,888
Acquired intangible asset amortization	2,218	2,405	2,491
Contingent consideration (gain) expense		(161)	675
Total operating costs and expenses	96,115	93,608	90,135
Operating (loss) income	(1,251)	6,469	(8,799)
Other (expense) income:
Investment income, net	656	1,097	851
Interest expense	(133)	(152)
Foreign exchange (loss) gain	(248)	134	239
(Loss) gain on strategic investments and other	(478)	10	177
Other (expense) income	(203)	1,089	1,267
(Loss) income before income taxes	(1,454)	7,558	(7,532)
Income tax benefit	2,577	34	3,075
Net income (loss)	$ 1,123	$ 7,592	$ (4,457)
Basic net income (loss) per share:	$ 0.08	$ 0.57	$ (0.34)
Diluted net income (loss) per share:	$ 0.08	$ 0.55	$ (0.34)
Weighted average number of shares outstanding:
Basic	13,552	13,389	13,157
Diluted	13,812	13,779	13,157
Product Sales [Member]
Revenue:
Total revenue	$ 44,317	$ 40,219	$ 37,953
Royalties and License Fees [Member]
Revenue:
Total revenue	40,634	48,458	35,424
Research, Development and Other [Member]
Revenue:
Total revenue	$ 9,913	$ 11,400	$ 7,959