Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Revenue:
Total revenue	$ 100,077	$ 81,336	$ 73,112
Operating costs and expenses:
Type of Cost, Good or Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Product costs	$ 13,639	$ 13,997	$ 11,422
Research and development	52,885	40,973	31,817
Selling, general and administrative	23,950	24,111	20,478
Acquired in-process research and development	890	7,888
Acquired intangible asset amortization	2,405	2,491	2,419
Contingent consideration (gain) expense	(161)	675	(127)
Total operating costs and expenses	93,608	90,135	66,009
Operating income (loss)	6,469	(8,799)	7,103
Other income (loss):
Investment income, net	1,097	851	390
Interest expense	(152)
Foreign exchange gain (loss)	134	239	(504)
Gains on strategic investments and other	10	177	44
Other income (loss)	1,089	1,267	(70)
Income (loss) before income taxes	7,558	(7,532)	7,033
Income tax benefit (provision)	34	3,075	(3,107)
Net income (loss)	$ 7,592	$ (4,457)	$ 3,926
Basic net income (loss) per share:	$ 0.57	$ (0.34)	$ 0.30
Diluted net income (loss) per share:	$ 0.55	$ (0.34)	$ 0.29
Weighted average number of shares outstanding:
Basic	13,389	13,157	13,153
Diluted	13,779	13,157	13,389
Product Sales [Member]
Revenue:
Total revenue	$ 40,219	$ 37,953	$ 32,790
Royalties and License Fees [Member]
Revenue:
Total revenue	48,458	35,424	31,787
Research, Development and Other [Member]
Revenue:
Total revenue	$ 11,400	$ 7,959	$ 8,535