Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Revenue:
Research, development and other	$ 2,857	$ 1,944	$ 5,251	$ 3,793
Total revenue	$ 22,676	$ 19,058	$ 44,917	$ 36,071
Operating costs and expenses:
Type of Cost, Good or Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Product costs	$ 3,093	$ 2,913	$ 6,616	$ 5,804
Research and development	13,555	10,774	25,041	18,605
Selling, general and administrative	4,876	6,440	10,825	11,628
Acquired intangible asset amortization	604	636	1,210	1,254
Contingent consideration gain	(317)	(2,230)	(352)	(1,112)
Total operating costs and expenses	21,811	18,533	43,340	36,179
Operating income (loss)	865	525	1,577	(108)
Other income (loss):
Investment income, net	265	142	581	263
Interest expense	(37)		(74)
Foreign exchange gain (loss)	5	(353)	141	(539)
Gain on strategic investment and other	2		9	177
Other income (loss), net	235	(211)	657	(99)
Income (loss) before income taxes	1,100	314	2,234	(207)
Income tax benefit	162	1,220	338	185
Net income (loss)	$ 1,262	$ 1,534	$ 2,572	$ (22)
Basic net income (loss) per share	$ 0.09	$ 0.12	$ 0.19	$ 0.00
Diluted net income (loss) per share	$ 0.09	$ 0.11	$ 0.19	$ 0.00
Weighted average number of shares outstanding:
Basic	13,390	13,102	13,379	13,078
Diluted	13,785	13,465	13,816	13,078
Product Sales [Member]
Revenue:
Revenue	$ 9,887	$ 8,686	$ 19,638	$ 16,774
Royalties and License Fees [Member]
Revenue:
Revenue	$ 9,932	$ 8,428	$ 20,028	$ 15,504