Note 16 - Customer Concentration (Detail) - Percentage of Total Revenue From Licenses Over 10% of Revenue	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Genentech [Member]
Licensees
Minimum threshold percent of total royalty income requiring disclosure by license by product name - year to date (in hundredths)	86.00%	86.00%	71.00%
Elan [Member]
Licensees
Minimum threshold percent of total royalty income requiring disclosure by license by product name - year to date (in hundredths)	12.00%	10.00%	9.00%
MedImmune [Member]
Licensees
Minimum threshold percent of total royalty income requiring disclosure by license by product name - year to date (in hundredths)	0.00%	0.00%	13.00%