Condensed Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Revenue:
Royalties and license fees	$ 7,329	$ 6,951	$ 14,794	$ 14,467
Product sales	5,165	5,758	10,565	11,111
Research and development	1,110	986	2,128	1,968
Total revenue	13,604	13,695	27,487	27,546
Operating costs and expenses:
Product costs	1,696	1,945	3,700	3,904
Research and development	4,134	3,774	7,833	7,136
Selling, general and administrative	4,294	3,847	8,145	7,500
Total operating costs and expenses	10,124	9,566	19,678	18,540
Operating income from continuing operations	3,480	4,129	7,809	9,006
Other income (loss):
Investment income, net	66	56	152	127
Impairment loss on strategic investment		(129)		(129)
Gain on sales of strategic investments		119	681	1,293
Other income, net	125	163	125	165
Other income, net	191	209	958	1,456
Income from continuing operations before income taxes	3,671	4,338	8,767	10,462
Income tax provision	(1,212)	(918)	(2,678)	(2,794)
Income from continuing operations	2,459	3,420	6,089	7,668
Discontinued operations:
Income from discontinued operations, net of income taxes		682		682
Income from discontinued operations		682		682
Net income	$ 2,459	$ 4,102	$ 6,089	$ 8,350
Basic income per share:
Continuing operations	$ 0.18	$ 0.23	$ 0.45	$ 0.52
Discontinued operations	$ 0.00	$ 0.05	$ 0.00	$ 0.05
Net income	$ 0.18	$ 0.28	$ 0.45	$ 0.57
Diluted income per share:
Continuing operations	$ 0.18	$ 0.23	$ 0.44	$ 0.52
Discontinued operations	$ 0.00	$ 0.05	$ 0.00	$ 0.05
Net income	$ 0.18	$ 0.28	$ 0.44	$ 0.56
Weighted average number of shares outstanding:
Basic	13,538	14,622	13,658	14,639
Diluted	13,824	14,914	13,925	14,871