Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Revenue:
Total revenue	$ 26,106	$ 34,995	$ 49,109	$ 57,292
Operating costs and expenses:
Cost, Product and Service [Extensible Enumeration]	Product Sales [Member]	Product Sales [Member]	Product Sales [Member]	Product Sales [Member]
Product costs	$ 5,107	$ 4,170	$ 9,604	$ 7,913
Research and development	13,712	12,875	25,375	23,757
Selling, general and administrative	11,113	7,907	20,305	14,930
Acquired intangible asset amortization	1,071	560	2,160	1,116
Contingent consideration expense	3		6
Total operating costs and expenses	31,006	25,512	57,450	47,716
Operating (loss) income	(4,900)	9,483	(8,341)	9,576
Other (expense) income:
Investment income, net	25	28	51	69
Interest expense	(129)	(59)	(265)	(119)
Foreign exchange gain (loss)	2	73	35	(107)
Other (expense) income	(102)	42	(179)	(157)
(Loss) income before income taxes	(5,002)	9,525	(8,520)	9,419
Income tax benefit (provision)	919	(1,438)	1,625	(1,606)
Net (loss) income	$ (4,083)	$ 8,087	$ (6,895)	$ 7,813
Basic net loss (income) per share	$ (0.29)	$ 0.59	$ (0.50)	$ 0.57
Diluted net loss (income) per share	$ (0.29)	$ 0.58	$ (0.50)	$ 0.56
Weighted average number of shares outstanding:
Basic	13,917	13,746	13,896	13,699
Diluted	13,917	13,981	13,896	13,915
Product Sales [Member]
Revenue:
Total revenue	$ 13,964	$ 11,783	$ 26,308	$ 21,885
Royalties and License Fees [Member]
Revenue:
Total revenue	9,844	20,052	17,943	29,386
Research, Development and Other [Member]
Revenue:
Total revenue	$ 2,298	$ 3,160	$ 4,858	$ 6,021