Condensed Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Revenue:
Royalties and license fees	$ 6,951	$ 6,283	$ 14,467	$ 12,893
Product sales	5,758	5,067	11,111	9,701
Research and development	986	860	1,968	1,532
Total revenue	13,695	12,210	27,546	24,126
Operating costs and expenses:
Product costs	1,945	1,615	3,904	3,205
Research and development	3,774	3,512	7,136	7,150
Selling, general and administrative	3,847	3,394	7,500	6,860
Total operating costs and expenses	9,566	8,521	18,540	17,215
Operating income from continuing operations	4,129	3,689	9,006	6,911
Other income (loss):
Investment income, net	56	143	127	281
Impairment loss on investments	(129)	(804)	(129)	(804)
Other income, net	282	162	1,458	170
Other income (loss)	209	(499)	1,456	(353)
Income from continuing operations before income taxes	4,338	3,190	10,462	6,558
Income tax provision	(918)	(1,244)	(2,794)	(2,457)
Income from continuing operations	3,420	1,946	7,668	4,101
Discontinued operations:
Income (loss) from discontinued operations, net of income taxes	682	(344)	682	1,261
Income (loss) on sale of discontinued operations, net of income taxes		121		(933)
Income (loss) from discontinued operations	682	(223)	682	328
Net income	$ 4,102	$ 1,723	$ 8,350	$ 4,429
Basic income (loss) per share:
Continuing operations	$ 0.23	$ 0.11	$ 0.52	$ 0.23
Discontinued operations	$ 0.05	$ (0.01)	$ 0.05	$ 0.02
Net income	$ 0.28	$ 0.10	$ 0.57	$ 0.25
Diluted income (loss) per share:
Continuing operations	$ 0.23	$ 0.11	$ 0.52	$ 0.23
Discontinued operations	$ 0.05	$ (0.01)	$ 0.05	$ 0.02
Net income	$ 0.28	$ 0.10	$ 0.56	$ 0.25
Weighted average number of shares outstanding:
Basic	14,622	17,519	14,639	17,498
Diluted	14,914	17,632	14,871	17,575